Annotation of win32/pcre/ChangeLog, revision 1.2

1.1       misha       1: ChangeLog for PCRE
                      2: ------------------
                      3: 
1.2     ! misha       4: Version 7.8 05-Sep-08
        !             5: ---------------------
        !             6: 
        !             7: 1.  Replaced UCP searching code with optimized version as implemented for Ad
        !             8:     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
        !             9:     stage table and inline lookup instead of a function, giving speed ups of 2
        !            10:     to 5 times on some simple patterns that I tested. Permission was given to
        !            11:     distribute the MultiStage2.py script that generates the tables (it's not in
        !            12:     the tarball, but is in the Subversion repository).
        !            13: 
        !            14: 2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
        !            15:     scripts.
        !            16: 
        !            17: 3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
        !            18:     a group with a zero qualifier. The result of the study could be incorrect,
        !            19:     or the function might crash, depending on the pattern.
        !            20: 
        !            21: 4.  Caseless matching was not working for non-ASCII characters in back
        !            22:     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
        !            23:     It now works when Unicode Property Support is available.
        !            24: 
        !            25: 5.  In pcretest, an escape such as \x{de} in the data was always generating
        !            26:     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
        !            27:     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
        !            28:     truncation.
        !            29: 
        !            30: 6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
        !            31: 
        !            32: 7.  Added two (int) casts to pcregrep when printing the difference of two
        !            33:     pointers, in case they are 64-bit values.
        !            34: 
        !            35: 8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
        !            36:     test 2 if it fails.
        !            37: 
        !            38: 9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
        !            39:     and a #define of that name to empty if it is not externally set. This is to
        !            40:     allow users of MSVC to set it if necessary.
        !            41: 
        !            42: 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
        !            43:     the convenience functions in the pcre_get.c source file.
        !            44: 
        !            45: 11. An option change at the start of a pattern that had top-level alternatives
        !            46:     could cause overwriting and/or a crash. This command provoked a crash in
        !            47:     some environments:
        !            48: 
        !            49:       printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
        !            50: 
        !            51:     This potential security problem was recorded as CVE-2008-2371.
        !            52: 
        !            53: 12. For a pattern where the match had to start at the beginning or immediately
        !            54:     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
        !            55:     pcre_dfa_exec() could read past the end of the passed subject if there was
        !            56:     no match. To help with detecting such bugs (e.g. with valgrind), I modified
        !            57:     pcretest so that it places the subject at the end of its malloc-ed buffer.
        !            58: 
        !            59: 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
        !            60:     exec() might read past the end of the data buffer in UTF-8 mode.
        !            61: 
        !            62: 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
        !            63:     the data contained the byte 0x85 as part of a UTF-8 character within its
        !            64:     first line. This applied both to normal and DFA matching.
        !            65: 
        !            66: 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
        !            67:     /^[^d]*?$/8 failed to match "abc".
        !            68: 
        !            69: 16. Added a missing copyright notice to pcrecpp_internal.h.
        !            70: 
        !            71: 17. Make it more clear in the documentation that values returned from
        !            72:     pcre_exec() in ovector are byte offsets, not character counts.
        !            73: 
        !            74: 18. Tidied a few places to stop certain compilers from issuing warnings.
        !            75: 
        !            76: 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
        !            77:     supplied by Stefan Weber. I made a further small update for 7.8 because
        !            78:     there is a change of source arrangements: the pcre_searchfuncs.c module is
        !            79:     replaced by pcre_ucd.c.
        !            80: 
        !            81: 
1.1       misha      82: Version 7.7 07-May-08
                     83: ---------------------
                     84: 
                     85: 1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
                     86:     a string to a long long, pretend we don't even have a long long." This is
                     87:     done by checking for the strtoq, strtoll, and _strtoi64 functions.
                     88: 
                     89: 2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
                     90:     pre-7.6 versions, which defined a global no_arg variable instead of putting
                     91:     it in the RE class. (See also #8 below.)
                     92: 
                     93: 3.  Remove a line of dead code, identified by coverity and reported by Nuno
                     94:     Lopes.
                     95: 
                     96: 4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
                     97: 
                     98:     (1) The include/exclude patterns were being applied to the whole pathnames
                     99:         of files, instead of just to the final components.
                    100: 
                    101:     (2) If there was more than one level of directory, the subdirectories were
                    102:         skipped unless they satisfied the include/exclude conditions. This is
                    103:         inconsistent with GNU grep (and could even be seen as contrary to the
                    104:         pcregrep specification - which I improved to make it absolutely clear).
                    105:         The action now is always to scan all levels of directory, and just
                    106:         apply the include/exclude patterns to regular files.
                    107: 
                    108: 5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
                    109:     --exclude_dir in the tests to avoid scanning .svn directories.
                    110: 
                    111: 6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
                    112:     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
                    113:     doesn't support NULs in patterns.
                    114: 
                    115: 7.  Added some missing "const"s to declarations of static tables in
                    116:     pcre_compile.c and pcre_dfa_exec.c.
                    117: 
                    118: 8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
                    119:     caused by fix #2  above. (Subsequently also a second patch to fix the
                    120:     first patch. And a third patch - this was a messy problem.)
                    121: 
                    122: 9.  Applied Craig's patch to remove the use of push_back().
                    123: 
                    124: 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
                    125:     matching function regexec().
                    126: 
                    127: 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
                    128:     which, however, unlike Perl's \g{...}, are subroutine calls, not back
                    129:     references. PCRE supports relative numbers with this syntax (I don't think
                    130:     Oniguruma does).
                    131: 
                    132: 12. Previously, a group with a zero repeat such as (...){0} was completely
                    133:     omitted from the compiled regex. However, this means that if the group
                    134:     was called as a subroutine from elsewhere in the pattern, things went wrong
                    135:     (an internal error was given). Such groups are now left in the compiled
                    136:     pattern, with a new opcode that causes them to be skipped at execution
                    137:     time.
                    138: 
                    139: 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
                    140:     to the way PCRE behaves:
                    141: 
                    142:     (a) A lone ] character is dis-allowed (Perl treats it as data).
                    143: 
                    144:     (b) A back reference to an unmatched subpattern matches an empty string
                    145:         (Perl fails the current match path).
                    146: 
                    147:     (c) A data ] in a character class must be notated as \] because if the
                    148:         first data character in a class is ], it defines an empty class. (In
                    149:         Perl it is not possible to have an empty class.) The empty class []
                    150:         never matches; it forces failure and is equivalent to (*FAIL) or (?!).
                    151:         The negative empty class [^] matches any one character, independently
                    152:         of the DOTALL setting.
                    153: 
                    154: 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
                    155:     non-existent subpattern following a character class starting with ']' and
                    156:     containing () gave an internal compiling error instead of "reference to
                    157:     non-existent subpattern". Fortunately, when the pattern did exist, the
                    158:     compiled code was correct. (When scanning forwards to check for the
                    159:     existencd of the subpattern, it was treating the data ']' as terminating
                    160:     the class, so got the count wrong. When actually compiling, the reference
                    161:     was subsequently set up correctly.)
                    162: 
                    163: 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
                    164:     it was being rejected as not supported by pcre_dfa_exec(), even though
                    165:     other assertions are supported. I have made pcre_dfa_exec() support
                    166:     (*FAIL).
                    167: 
                    168: 16. The implementation of 13c above involved the invention of a new opcode,
                    169:     OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
                    170:     cannot be changed at match time, I realized I could make a small
                    171:     improvement to matching performance by compiling OP_ALLANY instead of
                    172:     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
                    173:     on the OP_ANY path.
                    174: 
                    175: 17. Compiling pcretest on Windows with readline support failed without the
                    176:     following two fixes: (1) Make the unistd.h include conditional on
                    177:     HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
                    178: 
                    179: 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
                    180:     ncurses library to be included for pcretest when ReadLine support is
                    181:     requested, but also to allow for it to be overridden. This patch came from
                    182:     Daniel Bergström.
                    183: 
                    184: 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
                    185:     as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
                    186:     any errors with the current Unicode tables. Thanks to Peter Kankowski for
                    187:     spotting this.
                    188: 
                    189: 
                    190: Version 7.6 28-Jan-08
                    191: ---------------------
                    192: 
                    193: 1.  A character class containing a very large number of characters with
                    194:     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
                    195:     overflow.
                    196: 
                    197: 2.  Patch to cut out the "long long" test in pcrecpp_unittest when
                    198:     HAVE_LONG_LONG is not defined.
                    199: 
                    200: 3.  Applied Christian Ehrlicher's patch to update the CMake build files to
                    201:     bring them up to date and include new features. This patch includes:
                    202: 
                    203:     - Fixed PH's badly added libz and libbz2 support.
                    204:     - Fixed a problem with static linking.
                    205:     - Added pcredemo. [But later removed - see 7 below.]
                    206:     - Fixed dftables problem and added an option.
                    207:     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
                    208:         HAVE_LONG_LONG.
                    209:     - Added readline support for pcretest.
                    210:     - Added an listing of the option settings after cmake has run.
                    211: 
                    212: 4.  A user submitted a patch to Makefile that makes it easy to create
                    213:     "pcre.dll" under mingw when using Configure/Make. I added stuff to
                    214:     Makefile.am that cause it to include this special target, without
                    215:     affecting anything else. Note that the same mingw target plus all
                    216:     the other distribution libraries and programs are now supported
                    217:     when configuring with CMake (see 6 below) instead of with
                    218:     Configure/Make.
                    219: 
                    220: 5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
                    221:     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
                    222:     exported in the Windows port". It has not yet been confirmed that the patch
                    223:     solves the problem, but it does no harm.
                    224: 
                    225: 6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
                    226:     NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
                    227:     with CMake, and also correct the comment about stack recursion.
                    228: 
                    229: 7.  Remove the automatic building of pcredemo from the ./configure system and
                    230:     from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
                    231:     of a program that users should build themselves after PCRE is installed, so
                    232:     building it automatically is not really right. What is more, it gave
                    233:     trouble in some build environments.
                    234: 
                    235: 8.  Further tidies to CMakeLists.txt from Sheri and Christian.
                    236: 
                    237: 
                    238: Version 7.5 10-Jan-08
                    239: ---------------------
                    240: 
                    241: 1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
                    242:     values in parens when parsing an RE using the C++ wrapper."
                    243: 
                    244: 2.  Negative specials like \S did not work in character classes in UTF-8 mode.
                    245:     Characters greater than 255 were excluded from the class instead of being
                    246:     included.
                    247: 
                    248: 3.  The same bug as (2) above applied to negated POSIX classes such as
                    249:     [:^space:].
                    250: 
                    251: 4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
                    252:     defined or documented. It seems to have been a typo for PCRE_STATIC, so
                    253:     I have changed it.
                    254: 
                    255: 5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
                    256:     first named subpattern) and a construct such as (?&a) would reference the
                    257:     first named subpattern whose name started with "a" (in other words, the
                    258:     length check was missing). Both these problems are fixed. "Subpattern name
                    259:     expected" is now given for (?&) (a zero-length name), and this patch also
                    260:     makes it give the same error for \k'' (previously it complained that that
                    261:     was a reference to a non-existent subpattern).
                    262: 
                    263: 6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
                    264:     this is right because (?- can be followed by option settings as well as by
                    265:     digits. I have, however, made the messages clearer.
                    266: 
                    267: 7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
                    268:     than the number used in the conditional) now cause a compile-time error.
                    269:     This is actually not compatible with Perl, which accepts such patterns, but
                    270:     treats the conditional as always being FALSE (as PCRE used to), but it
                    271:     seems to me that giving a diagnostic is better.
                    272: 
                    273: 8.  Change "alphameric" to the more common word "alphanumeric" in comments
                    274:     and messages.
                    275: 
                    276: 9.  Fix two occurrences of "backslash" in comments that should have been
                    277:     "backspace".
                    278: 
                    279: 10. Remove two redundant lines of code that can never be obeyed (their function
                    280:     was moved elsewhere).
                    281: 
                    282: 11. The program that makes PCRE's Unicode character property table had a bug
                    283:     which caused it to generate incorrect table entries for sequences of
                    284:     characters that have the same character type, but are in different scripts.
                    285:     It amalgamated them into a single range, with the script of the first of
                    286:     them. In other words, some characters were in the wrong script. There were
                    287:     thirteen such cases, affecting characters in the following ranges:
                    288: 
                    289:       U+002b0 - U+002c1
                    290:       U+0060c - U+0060d
                    291:       U+0061e - U+00612
                    292:       U+0064b - U+0065e
                    293:       U+0074d - U+0076d
                    294:       U+01800 - U+01805
                    295:       U+01d00 - U+01d77
                    296:       U+01d9b - U+01dbf
                    297:       U+0200b - U+0200f
                    298:       U+030fc - U+030fe
                    299:       U+03260 - U+0327f
                    300:       U+0fb46 - U+0fbb1
                    301:       U+10450 - U+1049d
                    302: 
                    303: 12. The -o option (show only the matching part of a line) for pcregrep was not
                    304:     compatible with GNU grep in that, if there was more than one match in a
                    305:     line, it showed only the first of them. It now behaves in the same way as
                    306:     GNU grep.
                    307: 
                    308: 13. If the -o and -v options were combined for pcregrep, it printed a blank
                    309:     line for every non-matching line. GNU grep prints nothing, and pcregrep now
                    310:     does the same. The return code can be used to tell if there were any
                    311:     non-matching lines.
                    312: 
                    313: 14. Added --file-offsets and --line-offsets to pcregrep.
                    314: 
                    315: 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
                    316:     infinitely looping recursion. The bug was that positive lookaheads were not
                    317:     being skipped when checking for a possible empty match (negative lookaheads
                    318:     and both kinds of lookbehind were skipped).
                    319: 
                    320: 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
                    321:     inclusion of <windows.h> to before rather than after the definition of
                    322:     INVALID_FILE_ATTRIBUTES (patch from David Byron).
                    323: 
                    324: 17. Specifying a possessive quantifier with a specific limit for a Unicode
                    325:     character property caused pcre_compile() to compile bad code, which led at
                    326:     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
                    327:     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
                    328:     caused the error; without that there was no problem.
                    329: 
                    330: 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
                    331: 
                    332: 19. Added --enable-pcretest-libreadline.
                    333: 
                    334: 20. In pcrecpp.cc, the variable 'count' was incremented twice in
                    335:     RE::GlobalReplace(). As a result, the number of replacements returned was
                    336:     double what it should be. I removed one of the increments, but Craig sent a
                    337:     later patch that removed the other one (the right fix) and added unit tests
                    338:     that check the return values (which was not done before).
                    339: 
                    340: 21. Several CMake things:
                    341: 
                    342:     (1) Arranged that, when cmake is used on Unix, the libraries end up with
                    343:         the names libpcre and libpcreposix, not just pcre and pcreposix.
                    344: 
                    345:     (2) The above change means that pcretest and pcregrep are now correctly
                    346:         linked with the newly-built libraries, not previously installed ones.
                    347: 
                    348:     (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
                    349: 
                    350: 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
                    351:     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
                    352:     UTF-8 newline character). The key issue is that the pattern starts .*;
                    353:     this means that the match must be either at the beginning, or after a
                    354:     newline. The bug was in the code for advancing after a failed match and
                    355:     checking that the new position followed a newline. It was not taking
                    356:     account of UTF-8 characters correctly.
                    357: 
                    358: 23. PCRE was behaving differently from Perl in the way it recognized POSIX
                    359:     character classes. PCRE was not treating the sequence [:...:] as a
                    360:     character class unless the ... were all letters. Perl, however, seems to
                    361:     allow any characters between [: and :], though of course it rejects as
                    362:     unknown any "names" that contain non-letters, because all the known class
                    363:     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
                    364:     for example, whereas PCRE did not - it did not recognize a POSIX character
                    365:     class. This seemed a bit dangerous, so the code has been changed to be
                    366:     closer to Perl. The behaviour is not identical to Perl, because PCRE will
                    367:     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
                    368:     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
                    369:     Perl does, and where it didn't before.
                    370: 
                    371: 24. Rewrite so as to remove the single use of %n from pcregrep because in some
                    372:     Windows environments %n is disabled by default.
                    373: 
                    374: 
                    375: Version 7.4 21-Sep-07
                    376: ---------------------
                    377: 
                    378: 1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
                    379:     means that a class such as [\s] counted as "explicit reference to CR or
                    380:     LF". That isn't really right - the whole point of the change was to try to
                    381:     help when there was an actual mention of one of the two characters. So now
                    382:     the change happens only if \r or \n (or a literal CR or LF) character is
                    383:     encountered.
                    384: 
                    385: 2.  The 32-bit options word was also used for 6 internal flags, but the numbers
                    386:     of both had grown to the point where there were only 3 bits left.
                    387:     Fortunately, there was spare space in the data structure, and so I have
                    388:     moved the internal flags into a new 16-bit field to free up more option
                    389:     bits.
                    390: 
                    391: 3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
                    392:     but did not set the internal JCHANGED flag - either of these is enough to
                    393:     control the way the "get" function works - but the PCRE_INFO_JCHANGED
                    394:     facility is supposed to tell if (?J) was ever used, so now (?J) at the
                    395:     start sets both bits.
                    396: 
                    397: 4.  Added options (at build time, compile time, exec time) to change \R from
                    398:     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
                    399: 
                    400: 5.  doc/pcresyntax.html was missing from the distribution.
                    401: 
                    402: 6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
                    403:     compatibility, even though it is no longer used.
                    404: 
                    405: 7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
                    406:     strtoull to pcrecpp.cc to select the available functions in WIN32 when the
                    407:     windows.h file is present (where different names are used). [This was
                    408:     reversed later after testing - see 16 below.]
                    409: 
                    410: 8.  Changed all #include <config.h> to #include "config.h". There were also
                    411:     some further <pcre.h> cases that I changed to "pcre.h".
                    412: 
                    413: 9.  When pcregrep was used with the --colour option, it missed the line ending
                    414:     sequence off the lines that it output.
                    415: 
                    416: 10. It was pointed out to me that arrays of string pointers cause lots of
                    417:     relocations when a shared library is dynamically loaded. A technique of
                    418:     using a single long string with a table of offsets can drastically reduce
                    419:     these. I have refactored PCRE in four places to do this. The result is
                    420:     dramatic:
                    421: 
                    422:       Originally:                          290
                    423:       After changing UCP table:            187
                    424:       After changing error message table:   43
                    425:       After changing table of "verbs"       36
                    426:       After changing table of Posix names   22
                    427: 
                    428:     Thanks to the folks working on Gregex for glib for this insight.
                    429: 
                    430: 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
                    431:     unicode-properties was also set.
                    432: 
                    433: 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
                    434: 
                    435: 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
                    436:     checked only for CRLF.
                    437: 
                    438: 14. Added casts to pcretest.c to avoid compiler warnings.
                    439: 
                    440: 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
                    441: 
                    442: 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
                    443:     and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
                    444:     entirely. This removes changes made in 7 above.
                    445: 
                    446: 17. The CMake files have been updated, and there is now more information about
                    447:     building with CMake in the NON-UNIX-USE document.
                    448: 
                    449: 
                    450: Version 7.3 28-Aug-07
                    451: ---------------------
                    452: 
                    453:  1. In the rejigging of the build system that eventually resulted in 7.1, the
                    454:     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
                    455:     brackets there is not right, since it causes compilers to look for an
                    456:     installed pcre.h, not the version that is in the source that is being
                    457:     compiled (which of course may be different). I have changed it back to:
                    458: 
                    459:       #include "pcre.h"
                    460: 
                    461:     I have a vague recollection that the change was concerned with compiling in
                    462:     different directories, but in the new build system, that is taken care of
                    463:     by the VPATH setting the Makefile.
                    464: 
                    465:  2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
                    466:     when the subject happened to end in the byte 0x85 (e.g. if the last
                    467:     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
                    468:     characters but of course it shouldn't be taken as a newline when it is part
                    469:     of another character. The bug was that, for an unlimited repeat of . in
                    470:     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
                    471:     characters when looking for a newline.
                    472: 
                    473:  3. A small performance improvement in the DOTALL UTF-8 mode .* case.
                    474: 
                    475:  4. Debugging: adjusted the names of opcodes for different kinds of parentheses
                    476:     in debug output.
                    477: 
                    478:  5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
                    479:     long printing in the pcrecpp unittest when running under MinGW.
                    480: 
                    481:  6. ESC_K was left out of the EBCDIC table.
                    482: 
                    483:  7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
                    484:     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
                    485:     limit also applies to "virtual nesting" when a pattern is recursive, and in
                    486:     this case 1000 isn't so big. I have been able to remove this limit at the
                    487:     expense of backing off one optimization in certain circumstances. Normally,
                    488:     when pcre_exec() would call its internal match() function recursively and
                    489:     immediately return the result unconditionally, it uses a "tail recursion"
                    490:     feature to save stack. However, when a subpattern that can match an empty
                    491:     string has an unlimited repetition quantifier, it no longer makes this
                    492:     optimization. That gives it a stack frame in which to save the data for
                    493:     checking that an empty string has been matched. Previously this was taken
                    494:     from the 1000-entry workspace that had been reserved. So now there is no
                    495:     explicit limit, but more stack is used.
                    496: 
                    497:  8. Applied Daniel's patches to solve problems with the import/export magic
                    498:     syntax that is required for Windows, and which was going wrong for the
                    499:     pcreposix and pcrecpp parts of the library. These were overlooked when this
                    500:     problem was solved for the main library.
                    501: 
                    502:  9. There were some crude static tests to avoid integer overflow when computing
                    503:     the size of patterns that contain repeated groups with explicit upper
                    504:     limits. As the maximum quantifier is 65535, the maximum group length was
                    505:     set at 30,000 so that the product of these two numbers did not overflow a
                    506:     32-bit integer. However, it turns out that people want to use groups that
                    507:     are longer than 30,000 bytes (though not repeat them that many times).
                    508:     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
                    509:     made it possible to implement the integer overflow checks in a much more
                    510:     dynamic way, which I have now done. The artificial limitation on group
                    511:     length has been removed - we now have only the limit on the total length of
                    512:     the compiled pattern, which depends on the LINK_SIZE setting.
                    513: 
                    514: 10. Fixed a bug in the documentation for get/copy named substring when
                    515:     duplicate names are permitted. If none of the named substrings are set, the
                    516:     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
                    517:     empty string.
                    518: 
                    519: 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
                    520:     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
                    521:     because the ] is interpreted as the first data character and the
                    522:     terminating ] is not found. PCRE has been made compatible with Perl in this
                    523:     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
                    524:     cause memory overwriting.
                    525: 
                    526: 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
                    527:     string has been matched (to stop an infinite loop). It was not recognizing
                    528:     a conditional subpattern that could match an empty string if that
                    529:     subpattern was within another subpattern. For example, it looped when
                    530:     trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
                    531:     condition was not nested. This bug has been fixed.
                    532: 
                    533: 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
                    534:     past the start of the subject in the presence of bytes with the top bit
                    535:     set, for example "\x8aBCD".
                    536: 
                    537: 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
                    538:     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
                    539: 
                    540: 14. Optimized (?!) to (*FAIL).
                    541: 
                    542: 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
                    543:     This restricts code points to be within the range 0 to 0x10FFFF, excluding
                    544:     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
                    545:     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
                    546:     does: it's just the validity check that is more restrictive.
                    547: 
                    548: 16. Inserted checks for integer overflows during escape sequence (backslash)
                    549:     processing, and also fixed erroneous offset values for syntax errors during
                    550:     backslash processing.
                    551: 
                    552: 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
                    553:     for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
                    554: 
                    555: 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
                    556:     caused an overrun.
                    557: 
                    558: 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
                    559:     something other than just ASCII characters) inside a group that had an
                    560:     unlimited repeat caused a loop at compile time (while checking to see
                    561:     whether the group could match an empty string).
                    562: 
                    563: 20. Debugging a pattern containing \p or \P could cause a crash. For example,
                    564:     [\P{Any}] did so. (Error in the code for printing property names.)
                    565: 
                    566: 21. An orphan \E inside a character class could cause a crash.
                    567: 
                    568: 22. A repeated capturing bracket such as (A)? could cause a wild memory
                    569:     reference during compilation.
                    570: 
                    571: 23. There are several functions in pcre_compile() that scan along a compiled
                    572:     expression for various reasons (e.g. to see if it's fixed length for look
                    573:     behind). There were bugs in these functions when a repeated \p or \P was
                    574:     present in the pattern. These operators have additional parameters compared
                    575:     with \d, etc, and these were not being taken into account when moving along
                    576:     the compiled data. Specifically:
                    577: 
                    578:     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
                    579:         length.
                    580: 
                    581:     (b) An item such as \pL+ within a repeated group could cause crashes or
                    582:         loops.
                    583: 
                    584:     (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
                    585:         "reference to non-existent subpattern" error.
                    586: 
                    587:     (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
                    588: 
                    589: 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
                    590:     characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
                    591: 
                    592: 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
                    593: 
                    594: 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
                    595:     character were causing crashes (broken optimization).
                    596: 
                    597: 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
                    598:     \p or \P) caused a compile-time loop.
                    599: 
                    600: 28. More problems have arisen in unanchored patterns when CRLF is a valid line
                    601:     break. For example, the unstudied pattern [\r\n]A does not match the string
                    602:     "\r\nA" because change 7.0/46 below moves the current point on by two
                    603:     characters after failing to match at the start. However, the pattern \nA
                    604:     *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
                    605:     the same is true. There doesn't seem any very clean way out of this, but
                    606:     what I have chosen to do makes the common cases work: PCRE now takes note
                    607:     of whether there can be an explicit match for \r or \n anywhere in the
                    608:     pattern, and if so, 7.0/46 no longer applies. As part of this change,
                    609:     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
                    610:     pattern has explicit CR or LF references.
                    611: 
                    612: 29. Added (*CR) etc for changing newline setting at start of pattern.
                    613: 
                    614: 
                    615: Version 7.2 19-Jun-07
                    616: ---------------------
                    617: 
                    618:  1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
                    619:     which is apparently normally available under Windows.
                    620: 
                    621:  2. Re-jig the pcregrep tests with different newline settings in an attempt
                    622:     to make them independent of the local environment's newline setting.
                    623: 
                    624:  3. Add code to configure.ac to remove -g from the CFLAGS default settings.
                    625: 
                    626:  4. Some of the "internals" tests were previously cut out when the link size
                    627:     was not 2, because the output contained actual offsets. The recent new
                    628:     "Z" feature of pcretest means that these can be cut out, making the tests
                    629:     usable with all link sizes.
                    630: 
                    631:  5. Implemented Stan Switzer's goto replacement for longjmp() when not using
                    632:     stack recursion. This gives a massive performance boost under BSD, but just
                    633:     a small improvement under Linux. However, it saves one field in the frame
                    634:     in all cases.
                    635: 
                    636:  6. Added more features from the forthcoming Perl 5.10:
                    637: 
                    638:     (a) (?-n) (where n is a string of digits) is a relative subroutine or
                    639:         recursion call. It refers to the nth most recently opened parentheses.
                    640: 
                    641:     (b) (?+n) is also a relative subroutine call; it refers to the nth next
                    642:         to be opened parentheses.
                    643: 
                    644:     (c) Conditions that refer to capturing parentheses can be specified
                    645:         relatively, for example, (?(-2)... or (?(+3)...
                    646: 
                    647:     (d) \K resets the start of the current match so that everything before
                    648:         is not part of it.
                    649: 
                    650:     (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
                    651: 
                    652:     (f) \g{name} is another synonym - part of Perl 5.10's unification of
                    653:         reference syntax.
                    654: 
                    655:     (g) (?| introduces a group in which the numbering of parentheses in each
                    656:         alternative starts with the same number.
                    657: 
                    658:     (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
                    659: 
                    660:  7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
                    661:     PCRE_INFO_JCHANGED.
                    662: 
                    663:  8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
                    664:     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
                    665:     for detecting groups that can match an empty string.
                    666: 
                    667:  9. A pattern with a very large number of alternatives (more than several
                    668:     hundred) was running out of internal workspace during the pre-compile
                    669:     phase, where pcre_compile() figures out how much memory will be needed. A
                    670:     bit of new cunning has reduced the workspace needed for groups with
                    671:     alternatives. The 1000-alternative test pattern now uses 12 bytes of
                    672:     workspace instead of running out of the 4096 that are available.
                    673: 
                    674: 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
                    675: 
                    676: 11. Applied patch from Google to remove an optimization that didn't quite work.
                    677:     The report of the bug said:
                    678: 
                    679:       pcrecpp::RE("a*").FullMatch("aaa") matches, while
                    680:       pcrecpp::RE("a*?").FullMatch("aaa") does not, and
                    681:       pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
                    682: 
                    683: 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
                    684:     it matched the wrong number of bytes.
                    685: 
                    686: 
                    687: Version 7.1 24-Apr-07
                    688: ---------------------
                    689: 
                    690:  1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
                    691:     that is more "standard", making use of automake and other Autotools. There
                    692:     is some re-arrangement of the files and adjustment of comments consequent
                    693:     on this.
                    694: 
                    695:  2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
                    696:     for recursive directory scanning broke on some systems because the files
                    697:     are not scanned in any specific order and on different systems the order
                    698:     was different. A call to "sort" has been inserted into RunGrepTest for the
                    699:     approprate test as a short-term fix. In the longer term there may be an
                    700:     alternative.
                    701: 
                    702:  3. I had an email from Eric Raymond about problems translating some of PCRE's
                    703:     man pages to HTML (despite the fact that I distribute HTML pages, some
                    704:     people do their own conversions for various reasons). The problems
                    705:     concerned the use of low-level troff macros .br and .in. I have therefore
                    706:     removed all such uses from the man pages (some were redundant, some could
                    707:     be replaced by .nf/.fi pairs). The 132html script that I use to generate
                    708:     HTML has been updated to handle .nf/.fi and to complain if it encounters
                    709:     .br or .in.
                    710: 
                    711:  4. Updated comments in configure.ac that get placed in config.h.in and also
                    712:     arranged for config.h to be included in the distribution, with the name
                    713:     config.h.generic, for the benefit of those who have to compile without
                    714:     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
                    715: 
                    716:  5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
                    717:     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
                    718:     makevp.bat for the current PCRE, using the additional files
                    719:     makevp_c.txt, makevp_l.txt, and pcregexp.pas.
                    720: 
                    721:  6. A Windows user reported a minor discrepancy with test 2, which turned out
                    722:     to be caused by a trailing space on an input line that had got lost in his
                    723:     copy. The trailing space was an accident, so I've just removed it.
                    724: 
                    725:  7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
                    726:     that is needed.
                    727: 
                    728:  8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
                    729:     as "const" (a) because they are and (b) because it helps the PHP
                    730:     maintainers who have recently made a script to detect big data structures
                    731:     in the php code that should be moved to the .rodata section. I remembered
                    732:     to update Builducptable as well, so it won't revert if ucptable.h is ever
                    733:     re-created.
                    734: 
                    735:  9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
                    736:     pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
                    737:     order to be able to cut out the UTF-8 tables in the latter when UTF-8
                    738:     support is not required. This saves 1.5-2K of code, which is important in
                    739:     some applications.
                    740: 
                    741:     Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
                    742:     so as not to refer to the tables, even though these functions will never be
                    743:     called when UTF-8 support is disabled. Otherwise there are problems with a
                    744:     shared library.
                    745: 
                    746: 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
                    747: 
                    748:     (a) It was defining its arguments as char * instead of void *.
                    749: 
                    750:     (b) It was assuming that all moves were upwards in memory; this was true
                    751:         a long time ago when I wrote it, but is no longer the case.
                    752: 
                    753:     The emulated memove() is provided for those environments that have neither
                    754:     memmove() nor bcopy(). I didn't think anyone used it these days, but that
                    755:     is clearly not the case, as these two bugs were recently reported.
                    756: 
                    757: 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
                    758:     and Detrail to create the HTML documentation, the .txt form of the man
                    759:     pages, and it removes trailing spaces from listed files. It also creates
                    760:     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
                    761:     case, it wraps all the #defines with #ifndefs. This script should be run
                    762:     before "make dist".
                    763: 
                    764: 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
                    765:     with Unicode property support.
                    766: 
                    767:     (a) For a maximizing quantifier, if the two different cases of the
                    768:         character were of different lengths in their UTF-8 codings (there are
                    769:         some cases like this - I found 11), and the matching function had to
                    770:         back up over a mixture of the two cases, it incorrectly assumed they
                    771:         were both the same length.
                    772: 
                    773:     (b) When PCRE was configured to use the heap rather than the stack for
                    774:         recursion during matching, it was not correctly preserving the data for
                    775:         the other case of a UTF-8 character when checking ahead for a match
                    776:         while processing a minimizing repeat. If the check also involved
                    777:         matching a wide character, but failed, corruption could cause an
                    778:         erroneous result when trying to check for a repeat of the original
                    779:         character.
                    780: 
                    781: 13. Some tidying changes to the testing mechanism:
                    782: 
                    783:     (a) The RunTest script now detects the internal link size and whether there
                    784:         is UTF-8 and UCP support by running ./pcretest -C instead of relying on
                    785:         values substituted by "configure". (The RunGrepTest script already did
                    786:         this for UTF-8.) The configure.ac script no longer substitutes the
                    787:         relevant variables.
                    788: 
                    789:     (b) The debugging options /B and /D in pcretest show the compiled bytecode
                    790:         with length and offset values. This means that the output is different
                    791:         for different internal link sizes. Test 2 is skipped for link sizes
                    792:         other than 2 because of this, bypassing the problem. Unfortunately,
                    793:         there was also a test in test 3 (the locale tests) that used /B and
                    794:         failed for link sizes other than 2. Rather than cut the whole test out,
                    795:         I have added a new /Z option to pcretest that replaces the length and
                    796:         offset values with spaces. This is now used to make test 3 independent
                    797:         of link size. (Test 2 will be tidied up later.)
                    798: 
                    799: 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
                    800:     segmentation fault instead of returning the appropriate error message.
                    801: 
                    802: 15. In multiline mode when the newline sequence was set to "any", the pattern
                    803:     ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
                    804:     This doesn't seem right; it now treats the CRLF combination as the line
                    805:     ending, and so does not match in that case. It's only a pattern such as ^$
                    806:     that would hit this one: something like ^ABC$ would have failed after \r
                    807:     and then tried again after \r\n.
                    808: 
                    809: 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
                    810:     in an attempt to make files that differ only in their line terminators
                    811:     compare equal. This works on Linux.
                    812: 
                    813: 17. Under certain error circumstances pcregrep might try to free random memory
                    814:     as it exited. This is now fixed, thanks to valgrind.
                    815: 
                    816: 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
                    817:     "abc\r\n\r\n", it found an unwanted second match after the second \r. This
                    818:     was because its rules for how to advance for /g after matching an empty
                    819:     string at the end of a line did not allow for this case. They now check for
                    820:     it specially.
                    821: 
                    822: 20. pcretest is supposed to handle patterns and data of any length, by
                    823:     extending its buffers when necessary. It was getting this wrong when the
                    824:     buffer for a data line had to be extended.
                    825: 
                    826: 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
                    827:     CRLF as a newline sequence.
                    828: 
                    829: 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
                    830:     out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
                    831:     I have nevertheless tidied it up.
                    832: 
                    833: 23. Added some casts to kill warnings from HP-UX ia64 compiler.
                    834: 
                    835: 24. Added a man page for pcre-config.
                    836: 
                    837: 
                    838: Version 7.0 19-Dec-06
                    839: ---------------------
                    840: 
                    841:  1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
                    842:     moving to gcc 4.1.1.
                    843: 
                    844:  2. The -S option for pcretest uses setrlimit(); I had omitted to #include
                    845:     sys/time.h, which is documented as needed for this function. It doesn't
                    846:     seem to matter on Linux, but it showed up on some releases of OS X.
                    847: 
                    848:  3. It seems that there are systems where bytes whose values are greater than
                    849:     127 match isprint() in the "C" locale. The "C" locale should be the
                    850:     default when a C program starts up. In most systems, only ASCII printing
                    851:     characters match isprint(). This difference caused the output from pcretest
                    852:     to vary, making some of the tests fail. I have changed pcretest so that:
                    853: 
                    854:     (a) When it is outputting text in the compiled version of a pattern, bytes
                    855:         other than 32-126 are always shown as hex escapes.
                    856: 
                    857:     (b) When it is outputting text that is a matched part of a subject string,
                    858:         it does the same, unless a different locale has been set for the match
                    859:         (using the /L modifier). In this case, it uses isprint() to decide.
                    860: 
                    861:  4. Fixed a major bug that caused incorrect computation of the amount of memory
                    862:     required for a compiled pattern when options that changed within the
                    863:     pattern affected the logic of the preliminary scan that determines the
                    864:     length. The relevant options are -x, and -i in UTF-8 mode. The result was
                    865:     that the computed length was too small. The symptoms of this bug were
                    866:     either the PCRE error "internal error: code overflow" from pcre_compile(),
                    867:     or a glibc crash with a message such as "pcretest: free(): invalid next
                    868:     size (fast)". Examples of patterns that provoked this bug (shown in
                    869:     pcretest format) are:
                    870: 
                    871:       /(?-x: )/x
                    872:       /(?x)(?-x: \s*#\s*)/
                    873:       /((?i)[\x{c0}])/8
                    874:       /(?i:[\x{c0}])/8
                    875: 
                    876:     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
                    877:     is now done differently.
                    878: 
                    879:  5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
                    880:     wrapper classes; (b) implement a new function in the C++ scanner that is
                    881:     more efficient than the old way of doing things because it avoids levels of
                    882:     recursion in the regex matching; (c) add a paragraph to the documentation
                    883:     for the FullMatch() function.
                    884: 
                    885:  6. The escape sequence \n was being treated as whatever was defined as
                    886:     "newline". Not only was this contrary to the documentation, which states
                    887:     that \n is character 10 (hex 0A), but it also went horribly wrong when
                    888:     "newline" was defined as CRLF. This has been fixed.
                    889: 
                    890:  7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
                    891:     was being set to -1 for the "end of line" case (supposedly a value that no
                    892:     character can have). Though this value is never used (the check for end of
                    893:     line is "zero bytes in current character"), it caused compiler complaints.
                    894:     I've changed it to 0xffffffff.
                    895: 
                    896:  8. In pcre_version.c, the version string was being built by a sequence of
                    897:     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
                    898:     string (as it is for production releases) called a macro with an empty
                    899:     argument. The C standard says the result of this is undefined. The gcc
                    900:     compiler treats it as an empty string (which was what was wanted) but it is
                    901:     reported that Visual C gives an error. The source has been hacked around to
                    902:     avoid this problem.
                    903: 
                    904:  9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
                    905:     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
                    906:     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
                    907:     of them did).
                    908: 
                    909: 10. Originally, pcretest opened its input and output without "b"; then I was
                    910:     told that "b" was needed in some environments, so it was added for release
                    911:     5.0 to both the input and output. (It makes no difference on Unix-like
                    912:     systems.) Later I was told that it is wrong for the input on Windows. I've
                    913:     now abstracted the modes into two macros, to make it easier to fiddle with
                    914:     them, and removed "b" from the input mode under Windows.
                    915: 
                    916: 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
                    917: 
                    918: 12. Added -help and --help to pcretest as an official way of being reminded
                    919:     of the options.
                    920: 
                    921: 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
                    922:     and pcrecpp.cc because they annoy compilers at high warning levels.
                    923: 
                    924: 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
                    925: 
                    926: 15. Fixed an occurrence of == in configure.ac that should have been = (shell
                    927:     scripts are not C programs :-) and which was not noticed because it works
                    928:     on Linux.
                    929: 
                    930: 16. pcretest is supposed to handle any length of pattern and data line (as one
                    931:     line or as a continued sequence of lines) by extending its input buffer if
                    932:     necessary. This feature was broken for very long pattern lines, leading to
                    933:     a string of junk being passed to pcre_compile() if the pattern was longer
                    934:     than about 50K.
                    935: 
                    936: 17. I have done a major re-factoring of the way pcre_compile() computes the
                    937:     amount of memory needed for a compiled pattern. Previously, there was code
                    938:     that made a preliminary scan of the pattern in order to do this. That was
                    939:     OK when PCRE was new, but as the facilities have expanded, it has become
                    940:     harder and harder to keep it in step with the real compile phase, and there
                    941:     have been a number of bugs (see for example, 4 above). I have now found a
                    942:     cunning way of running the real compile function in a "fake" mode that
                    943:     enables it to compute how much memory it would need, while actually only
                    944:     ever using a few hundred bytes of working memory and without too many
                    945:     tests of the mode. This should make future maintenance and development
                    946:     easier. A side effect of this work is that the limit of 200 on the nesting
                    947:     depth of parentheses has been removed (though this was never a serious
                    948:     limitation, I suspect). However, there is a downside: pcre_compile() now
                    949:     runs more slowly than before (30% or more, depending on the pattern). I
                    950:     hope this isn't a big issue. There is no effect on runtime performance.
                    951: 
                    952: 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
                    953:     newline (only possible for the last line of a file) and it was a
                    954:     pattern that set a locale (followed by /Lsomething), pcretest crashed.
                    955: 
                    956: 19. Added additional timing features to pcretest. (1) The -tm option now times
                    957:     matching only, not compiling. (2) Both -t and -tm can be followed, as a
                    958:     separate command line item, by a number that specifies the number of
                    959:     repeats to use when timing. The default is 50000; this gives better
                    960:     precision, but takes uncomfortably long for very large patterns.
                    961: 
                    962: 20. Extended pcre_study() to be more clever in cases where a branch of a
                    963:     subpattern has no definite first character. For example, (a*|b*)[cd] would
                    964:     previously give no result from pcre_study(). Now it recognizes that the
                    965:     first character must be a, b, c, or d.
                    966: 
                    967: 21. There was an incorrect error "recursive call could loop indefinitely" if
                    968:     a subpattern (or the entire pattern) that was being tested for matching an
                    969:     empty string contained only one non-empty item after a nested subpattern.
                    970:     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
                    971:     incorrectly, because the \d was being skipped in the check.
                    972: 
                    973: 22. The pcretest program now has a new pattern option /B and a command line
                    974:     option -b, which is equivalent to adding /B to every pattern. This causes
                    975:     it to show the compiled bytecode, without the additional information that
                    976:     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
                    977:     is the same as /B/I).
                    978: 
                    979: 23. A new optimization is now able automatically to treat some sequences such
                    980:     as a*b as a*+b. More specifically, if something simple (such as a character
                    981:     or a simple class like \d) has an unlimited quantifier, and is followed by
                    982:     something that cannot possibly match the quantified thing, the quantifier
                    983:     is automatically "possessified".
                    984: 
                    985: 24. A recursive reference to a subpattern whose number was greater than 39
                    986:     went wrong under certain circumstances in UTF-8 mode. This bug could also
                    987:     have affected the operation of pcre_study().
                    988: 
                    989: 25. Realized that a little bit of performance could be had by replacing
                    990:     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
                    991: 
                    992: 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
                    993: 
                    994: 27. Possessive quantifiers such as a++ were previously implemented by turning
                    995:     them into atomic groups such as ($>a+). Now they have their own opcodes,
                    996:     which improves performance. This includes the automatically created ones
                    997:     from 23 above.
                    998: 
                    999: 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
                   1000:     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
                   1001:     the first matched character to be a colon. This applied both to named and
                   1002:     numbered groups.
                   1003: 
                   1004: 29. The ucpinternal.h header file was missing its idempotency #ifdef.
                   1005: 
                   1006: 30. I was sent a "project" file called libpcre.a.dev which I understand makes
                   1007:     building PCRE on Windows easier, so I have included it in the distribution.
                   1008: 
                   1009: 31. There is now a check in pcretest against a ridiculously large number being
                   1010:     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
                   1011:     loop, the loop is abandoned.
                   1012: 
                   1013: 32. Forward references to subpatterns in conditions such as (?(2)...) where
                   1014:     subpattern 2 is defined later cause pcre_compile() to search forwards in
                   1015:     the pattern for the relevant set of parentheses. This search went wrong
                   1016:     when there were unescaped parentheses in a character class, parentheses
                   1017:     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
                   1018: 
                   1019: 33. "Subroutine" calls and backreferences were previously restricted to
                   1020:     referencing subpatterns earlier in the regex. This restriction has now
                   1021:     been removed.
                   1022: 
                   1023: 34. Added a number of extra features that are going to be in Perl 5.10. On the
                   1024:     whole, these are just syntactic alternatives for features that PCRE had
                   1025:     previously implemented using the Python syntax or my own invention. The
                   1026:     other formats are all retained for compatibility.
                   1027: 
                   1028:     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
                   1029:         as (?P<name>...). The new forms, as well as being in Perl 5.10, are
                   1030:         also .NET compatible.
                   1031: 
                   1032:     (b) A recursion or subroutine call to a named group can now be defined as
                   1033:         (?&name) as well as (?P>name).
                   1034: 
                   1035:     (c) A backreference to a named group can now be defined as \k<name> or
                   1036:         \k'name' as well as (?P=name). The new forms, as well as being in Perl
                   1037:         5.10, are also .NET compatible.
                   1038: 
                   1039:     (d) A conditional reference to a named group can now use the syntax
                   1040:         (?(<name>) or (?('name') as well as (?(name).
                   1041: 
                   1042:     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
                   1043:         groups (named and numbered) that are never evaluated inline, but can be
                   1044:         called as "subroutines" from elsewhere. In effect, the DEFINE condition
                   1045:         is always false. There may be only one alternative in such a group.
                   1046: 
                   1047:     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
                   1048:         as the simple (?(R). The condition is true only if the most recent
                   1049:         recursion is that of the given number or name. It does not search out
                   1050:         through the entire recursion stack.
                   1051: 
                   1052:     (g) The escape \gN or \g{N} has been added, where N is a positive or
                   1053:         negative number, specifying an absolute or relative reference.
                   1054: 
                   1055: 35. Tidied to get rid of some further signed/unsigned compiler warnings and
                   1056:     some "unreachable code" warnings.
                   1057: 
                   1058: 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
                   1059:     things, this adds five new scripts.
                   1060: 
                   1061: 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
                   1062:     There were also incompatibilities regarding the handling of \Q..\E inside
                   1063:     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
                   1064:     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
                   1065: 
                   1066: 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
                   1067:     matches an empty string, and forcibly breaks the loop. There were bugs in
                   1068:     this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
                   1069:     against  aaaa  the result was just "a" rather than "aaaa", for example. Two
                   1070:     separate and independent bugs (that affected different cases) have been
                   1071:     fixed.
                   1072: 
                   1073: 39. Refactored the code to abolish the use of different opcodes for small
                   1074:     capturing bracket numbers. This is a tidy that I avoided doing when I
                   1075:     removed the limit on the number of capturing brackets for 3.5 back in 2001.
                   1076:     The new approach is not only tidier, it makes it possible to reduce the
                   1077:     memory needed to fix the previous bug (38).
                   1078: 
                   1079: 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
                   1080:     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
                   1081:     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
                   1082:     mode.
                   1083: 
                   1084: 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
                   1085:     report.
                   1086: 
                   1087: 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
                   1088:     copy construction and assignment in the C++ wrapper.
                   1089: 
                   1090: 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
                   1091:     couple of bugs that could have given wrong results in the "--newline=crlf"
                   1092:     case.
                   1093: 
                   1094: 44. Added a number of casts and did some reorganization of signed/unsigned int
                   1095:     variables following suggestions from Dair Grant. Also renamed the variable
                   1096:     "this" as "item" because it is a C++ keyword.
                   1097: 
                   1098: 45. Arranged for dftables to add
                   1099: 
                   1100:       #include "pcre_internal.h"
                   1101: 
                   1102:     to pcre_chartables.c because without it, gcc 4.x may remove the array
                   1103:     definition from the final binary if PCRE is built into a static library and
                   1104:     dead code stripping is activated.
                   1105: 
                   1106: 46. For an unanchored pattern, if a match attempt fails at the start of a
                   1107:     newline sequence, and the newline setting is CRLF or ANY, and the next two
                   1108:     characters are CRLF, advance by two characters instead of one.
                   1109: 
                   1110: 
                   1111: Version 6.7 04-Jul-06
                   1112: ---------------------
                   1113: 
                   1114:  1. In order to handle tests when input lines are enormously long, pcretest has
                   1115:     been re-factored so that it automatically extends its buffers when
                   1116:     necessary. The code is crude, but this _is_ just a test program. The
                   1117:     default size has been increased from 32K to 50K.
                   1118: 
                   1119:  2. The code in pcre_study() was using the value of the re argument before
                   1120:     testing it for NULL. (Of course, in any sensible call of the function, it
                   1121:     won't be NULL.)
                   1122: 
                   1123:  3. The memmove() emulation function in pcre_internal.h, which is used on
                   1124:     systems that lack both memmove() and bcopy() - that is, hardly ever -
                   1125:     was missing a "static" storage class specifier.
                   1126: 
                   1127:  4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
                   1128:     containing an extended class (one that cannot be represented by a bitmap
                   1129:     because it contains high-valued characters or Unicode property items, e.g.
                   1130:     [\pZ]). Almost always one would set UTF-8 mode when processing such a
                   1131:     pattern, but PCRE should not loop if you do not (it no longer does).
                   1132:     [Detail: two cases were found: (a) a repeated subpattern containing an
                   1133:     extended class; (b) a recursive reference to a subpattern that followed a
                   1134:     previous extended class. It wasn't skipping over the extended class
                   1135:     correctly when UTF-8 mode was not set.]
                   1136: 
                   1137:  5. A negated single-character class was not being recognized as fixed-length
                   1138:     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
                   1139:     compile error "lookbehind assertion is not fixed length".
                   1140: 
                   1141:  6. The RunPerlTest auxiliary script was showing an unexpected difference
                   1142:     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
                   1143:     write a Perl script that can interpret lines of an input file either as
                   1144:     byte characters or as UTF-8, which is what "perltest" was being required to
                   1145:     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
                   1146:     can't do is switch easily at run time between having the "use utf8;" pragma
                   1147:     or not. In the end, I fudged it by using the RunPerlTest script to insert
                   1148:     "use utf8;" explicitly for the UTF-8 tests.
                   1149: 
                   1150:  7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
                   1151:     the end of the subject string, contrary to the documentation and to what
                   1152:     Perl does. This was true of both matching functions. Now it matches only at
                   1153:     the start of the subject and immediately after *internal* newlines.
                   1154: 
                   1155:  8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
                   1156:     a pointer to an int instead of a pointer to an unsigned long int. This
                   1157:     caused problems on 64-bit systems.
                   1158: 
                   1159:  9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
                   1160:     instance of the 'standard' template library not being so standard".
                   1161: 
                   1162: 10. There was no check on the number of named subpatterns nor the maximum
                   1163:     length of a subpattern name. The product of these values is used to compute
                   1164:     the size of the memory block for a compiled pattern. By supplying a very
                   1165:     long subpattern name and a large number of named subpatterns, the size
                   1166:     computation could be caused to overflow. This is now prevented by limiting
                   1167:     the length of names to 32 characters, and the number of named subpatterns
                   1168:     to 10,000.
                   1169: 
                   1170: 11. Subpatterns that are repeated with specific counts have to be replicated in
                   1171:     the compiled pattern. The size of memory for this was computed from the
                   1172:     length of the subpattern and the repeat count. The latter is limited to
                   1173:     65535, but there was no limit on the former, meaning that integer overflow
                   1174:     could in principle occur. The compiled length of a repeated subpattern is
                   1175:     now limited to 30,000 bytes in order to prevent this.
                   1176: 
                   1177: 12. Added the optional facility to have named substrings with the same name.
                   1178: 
                   1179: 13. Added the ability to use a named substring as a condition, using the
                   1180:     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
                   1181:     are numbers (not recommended). Forward references are permitted.
                   1182: 
                   1183: 14. Added forward references in named backreferences (if you see what I mean).
                   1184: 
                   1185: 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
                   1186:     pattern could run off the end of the subject. For example, the pattern
                   1187:     "(?s)(.{1,5})"8 did this with the subject "ab".
                   1188: 
                   1189: 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
                   1190:     PCRE_CASELESS was set when matching characters that were quantified with ?
                   1191:     or *.
                   1192: 
                   1193: 17. A character class other than a single negated character that had a minimum
                   1194:     but no maximum quantifier - for example [ab]{6,} - was not handled
                   1195:     correctly by pce_dfa_exec(). It would match only one character.
                   1196: 
                   1197: 18. A valid (though odd) pattern that looked like a POSIX character
                   1198:     class but used an invalid character after [ (for example [[,abc,]]) caused
                   1199:     pcre_compile() to give the error "Failed: internal error: code overflow" or
                   1200:     in some cases to crash with a glibc free() error. This could even happen if
                   1201:     the pattern terminated after [[ but there just happened to be a sequence of
                   1202:     letters, a binary zero, and a closing ] in the memory that followed.
                   1203: 
                   1204: 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
                   1205:     over the years. Originally (before any Unicode support), just the bottom 8
                   1206:     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
                   1207:     output from "man perlunicode" includes this:
                   1208: 
                   1209:       The regular expression compiler produces polymorphic opcodes.  That
                   1210:       is, the pattern adapts to the data and automatically switches to
                   1211:       the Unicode character scheme when presented with Unicode data--or
                   1212:       instead uses a traditional byte scheme when presented with byte
                   1213:       data.
                   1214: 
                   1215:     Sadly, a wide octal escape does not cause a switch, and in a string with
                   1216:     no other multibyte characters, these octal escapes are treated as before.
                   1217:     Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
                   1218:     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
                   1219:     Unicode string.
                   1220: 
                   1221:     I have not perpetrated such confusion in PCRE. Up till now, it took just
                   1222:     the bottom 8 bits, as in old Perl. I have now made octal escapes with
                   1223:     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
                   1224:     translate to the appropriate multibyte character.
                   1225: 
                   1226: 29. Applied some refactoring to reduce the number of warnings from Microsoft
                   1227:     and Borland compilers. This has included removing the fudge introduced
                   1228:     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
                   1229:     a warning about an unused variable.
                   1230: 
                   1231: 21. PCRE has not included VT (character 0x0b) in the set of whitespace
                   1232:     characters since release 4.0, because Perl (from release 5.004) does not.
                   1233:     [Or at least, is documented not to: some releases seem to be in conflict
                   1234:     with the documentation.] However, when a pattern was studied with
                   1235:     pcre_study() and all its branches started with \s, PCRE still included VT
                   1236:     as a possible starting character. Of course, this did no harm; it just
                   1237:     caused an unnecessary match attempt.
                   1238: 
                   1239: 22. Removed a now-redundant internal flag bit that recorded the fact that case
                   1240:     dependency changed within the pattern. This was once needed for "required
                   1241:     byte" processing, but is no longer used. This recovers a now-scarce options
                   1242:     bit. Also moved the least significant internal flag bit to the most-
                   1243:     significant bit of the word, which was not previously used (hangover from
                   1244:     the days when it was an int rather than a uint) to free up another bit for
                   1245:     the future.
                   1246: 
                   1247: 23. Added support for CRLF line endings as well as CR and LF. As well as the
                   1248:     default being selectable at build time, it can now be changed at runtime
                   1249:     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
                   1250:     specify that it is scanning data with non-default line endings.
                   1251: 
                   1252: 24. Changed the definition of CXXLINK to make it agree with the definition of
                   1253:     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
                   1254: 
                   1255: 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
                   1256:     recursions. This makes a big different to stack usage for some patterns.
                   1257: 
                   1258: 26. If a subpattern containing a named recursion or subroutine reference such
                   1259:     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
                   1260:     the space required for the compiled pattern went wrong and gave too small a
                   1261:     value. Depending on the environment, this could lead to "Failed: internal
                   1262:     error: code overflow at offset 49" or "glibc detected double free or
                   1263:     corruption" errors.
                   1264: 
                   1265: 27. Applied patches from Google (a) to support the new newline modes and (b) to
                   1266:     advance over multibyte UTF-8 characters in GlobalReplace.
                   1267: 
                   1268: 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
                   1269:     difference for some implementation of PCRE in some Windows version.
                   1270: 
                   1271: 29. Added some extra testing facilities to pcretest:
                   1272: 
                   1273:     \q<number>   in a data line sets the "match limit" value
                   1274:     \Q<number>   in a data line sets the "match recursion limt" value
                   1275:     -S <number>  sets the stack size, where <number> is in megabytes
                   1276: 
                   1277:     The -S option isn't available for Windows.
                   1278: 
                   1279: 
                   1280: Version 6.6 06-Feb-06
                   1281: ---------------------
                   1282: 
                   1283:  1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
                   1284:     in pcreposix.h. I have copied the definition from pcre.h.
                   1285: 
                   1286:  2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
                   1287:     because pcre.h is no longer a built file.
                   1288: 
                   1289:  3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
                   1290:     not normally included in the compiled code.
                   1291: 
                   1292: 
                   1293: Version 6.5 01-Feb-06
                   1294: ---------------------
                   1295: 
                   1296:  1. When using the partial match feature with pcre_dfa_exec(), it was not
                   1297:     anchoring the second and subsequent partial matches at the new starting
                   1298:     point. This could lead to incorrect results. For example, with the pattern
                   1299:     /1234/, partially matching against "123" and then "a4" gave a match.
                   1300: 
                   1301:  2. Changes to pcregrep:
                   1302: 
                   1303:     (a) All non-match returns from pcre_exec() were being treated as failures
                   1304:         to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
                   1305:         error message is output. Some extra information is given for the
                   1306:         PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
                   1307:         probably the only errors that are likely to be caused by users (by
                   1308:         specifying a regex that has nested indefinite repeats, for instance).
                   1309:         If there are more than 20 of these errors, pcregrep is abandoned.
                   1310: 
                   1311:     (b) A binary zero was treated as data while matching, but terminated the
                   1312:         output line if it was written out. This has been fixed: binary zeroes
                   1313:         are now no different to any other data bytes.
                   1314: 
                   1315:     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
                   1316:         used to set a locale for matching. The --locale=xxxx long option has
                   1317:         been added (no short equivalent) to specify a locale explicitly on the
                   1318:         pcregrep command, overriding the environment variables.
                   1319: 
                   1320:     (d) When -B was used with -n, some line numbers in the output were one less
                   1321:         than they should have been.
                   1322: 
                   1323:     (e) Added the -o (--only-matching) option.
                   1324: 
                   1325:     (f) If -A or -C was used with -c (count only), some lines of context were
                   1326:         accidentally printed for the final match.
                   1327: 
                   1328:     (g) Added the -H (--with-filename) option.
                   1329: 
                   1330:     (h) The combination of options -rh failed to suppress file names for files
                   1331:         that were found from directory arguments.
                   1332: 
                   1333:     (i) Added the -D (--devices) and -d (--directories) options.
                   1334: 
                   1335:     (j) Added the -F (--fixed-strings) option.
                   1336: 
                   1337:     (k) Allow "-" to be used as a file name for -f as well as for a data file.
                   1338: 
                   1339:     (l) Added the --colo(u)r option.
                   1340: 
                   1341:     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
                   1342:         is not present by default.
                   1343: 
                   1344:  3. A nasty bug was discovered in the handling of recursive patterns, that is,
                   1345:     items such as (?R) or (?1), when the recursion could match a number of
                   1346:     alternatives. If it matched one of the alternatives, but subsequently,
                   1347:     outside the recursion, there was a failure, the code tried to back up into
                   1348:     the recursion. However, because of the way PCRE is implemented, this is not
                   1349:     possible, and the result was an incorrect result from the match.
                   1350: 
                   1351:     In order to prevent this happening, the specification of recursion has
                   1352:     been changed so that all such subpatterns are automatically treated as
                   1353:     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
                   1354: 
                   1355:  4. I had overlooked the fact that, in some locales, there are characters for
                   1356:     which isalpha() is true but neither isupper() nor islower() are true. In
                   1357:     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
                   1358:     and ordfeminine) are like this. This affected the treatment of \w and \W
                   1359:     when they appeared in character classes, but not when they appeared outside
                   1360:     a character class. The bit map for "word" characters is now created
                   1361:     separately from the results of isalnum() instead of just taking it from the
                   1362:     upper, lower, and digit maps. (Plus the underscore character, of course.)
                   1363: 
                   1364:  5. The above bug also affected the handling of POSIX character classes such as
                   1365:     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
                   1366:     permanent tables. Instead, the bit maps for such a class were previously
                   1367:     created as the appropriate unions of the upper, lower, and digit bitmaps.
                   1368:     Now they are created by subtraction from the [[:word:]] class, which has
                   1369:     its own bitmap.
                   1370: 
                   1371:  6. The [[:blank:]] character class matches horizontal, but not vertical space.
                   1372:     It is created by subtracting the vertical space characters (\x09, \x0a,
                   1373:     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
                   1374:     subtraction was done in the overall bitmap for a character class, meaning
                   1375:     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
                   1376:     be recognized. This bug has been fixed.
                   1377: 
                   1378:  7. Patches from the folks at Google:
                   1379: 
                   1380:       (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
                   1381:       real life, but is still worth protecting against".
                   1382: 
                   1383:       (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
                   1384:       regular expressions".
                   1385: 
                   1386:       (c) pcre_scanner.cc: avoid use of std::count() because not all systems
                   1387:       have it.
                   1388: 
                   1389:       (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
                   1390:       "configure" and the latter not, in order to fix a problem somebody had
                   1391:       with compiling the Arg class on HP-UX.
                   1392: 
                   1393:       (e) Improve the error-handling of the C++ wrapper a little bit.
                   1394: 
                   1395:       (f) New tests for checking recursion limiting.
                   1396: 
                   1397:  8. The pcre_memmove() function, which is used only if the environment does not
                   1398:     have a standard memmove() function (and is therefore rarely compiled),
                   1399:     contained two bugs: (a) use of int instead of size_t, and (b) it was not
                   1400:     returning a result (though PCRE never actually uses the result).
                   1401: 
                   1402:  9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
                   1403:     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
                   1404:     returned instead of calling malloc() with an overflowing number that would
                   1405:     most likely cause subsequent chaos.
                   1406: 
                   1407: 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
                   1408: 
                   1409: 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
                   1410:     with this option is matched, the nmatch and pmatch options of regexec() are
                   1411:     ignored.
                   1412: 
                   1413: 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
                   1414:     provided in case anyone wants to the the POSIX interface with UTF-8
                   1415:     strings.
                   1416: 
                   1417: 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
                   1418:     C++ linking (needed for some HP-UX environments).
                   1419: 
                   1420: 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
                   1421:     (unused parameter) and in the pcre_printint() function (omitted "default"
                   1422:     switch label when the default is to do nothing).
                   1423: 
                   1424: 15. Added some code to make it possible, when PCRE is compiled as a C++
                   1425:     library, to replace subject pointers for pcre_exec() with a smart pointer
                   1426:     class, thus making it possible to process discontinuous strings.
                   1427: 
                   1428: 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
                   1429:     much the same function. They were added by different people who were trying
                   1430:     to make PCRE easy to compile on non-Unix systems. It has been suggested
                   1431:     that PCRE_EXPORT be abolished now that there is more automatic apparatus
                   1432:     for compiling on Windows systems. I have therefore replaced it with
                   1433:     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
                   1434:     defaults to "extern" for C or "extern C" for C++, which works fine on
                   1435:     Unix-like systems. It is now possible to override the value of PCRE_DATA_
                   1436:     SCOPE with something explicit in config.h. In addition:
                   1437: 
                   1438:     (a) pcreposix.h still had just "extern" instead of either of these macros;
                   1439:         I have replaced it with PCRE_DATA_SCOPE.
                   1440: 
                   1441:     (b) Functions such as _pcre_xclass(), which are internal to the library,
                   1442:         but external in the C sense, all had PCRE_EXPORT in their definitions.
                   1443:         This is apparently wrong for the Windows case, so I have removed it.
                   1444:         (It makes no difference on Unix-like systems.)
                   1445: 
                   1446: 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
                   1447:     of recursive calls to match(). This is different to MATCH_LIMIT because
                   1448:     that limits the total number of calls to match(), not all of which increase
                   1449:     the depth of recursion. Limiting the recursion depth limits the amount of
                   1450:     stack (or heap if NO_RECURSE is set) that is used. The default can be set
                   1451:     when PCRE is compiled, and changed at run time. A patch from Google adds
                   1452:     this functionality to the C++ interface.
                   1453: 
                   1454: 18. Changes to the handling of Unicode character properties:
                   1455: 
                   1456:     (a) Updated the table to Unicode 4.1.0.
                   1457: 
                   1458:     (b) Recognize characters that are not in the table as "Cn" (undefined).
                   1459: 
                   1460:     (c) I revised the way the table is implemented to a much improved format
                   1461:         which includes recognition of ranges. It now supports the ranges that
                   1462:         are defined in UnicodeData.txt, and it also amalgamates other
                   1463:         characters into ranges. This has reduced the number of entries in the
                   1464:         table from around 16,000 to around 3,000, thus reducing its size
                   1465:         considerably. I realized I did not need to use a tree structure after
                   1466:         all - a binary chop search is just as efficient. Having reduced the
                   1467:         number of entries, I extended their size from 6 bytes to 8 bytes to
                   1468:         allow for more data.
                   1469: 
                   1470:     (d) Added support for Unicode script names via properties such as \p{Han}.
                   1471: 
                   1472: 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
                   1473:     matching that character.
                   1474: 
                   1475: 20. When matching a repeated Unicode property with a minimum greater than zero,
                   1476:     (for example \pL{2,}), PCRE could look past the end of the subject if it
                   1477:     reached it while seeking the minimum number of characters. This could
                   1478:     happen only if some of the characters were more than one byte long, because
                   1479:     there is a check for at least the minimum number of bytes.
                   1480: 
                   1481: 21. Refactored the implementation of \p and \P so as to be more general, to
                   1482:     allow for more different types of property in future. This has changed the
                   1483:     compiled form incompatibly. Anybody with saved compiled patterns that use
                   1484:     \p or \P will have to recompile them.
                   1485: 
                   1486: 22. Added "Any" and "L&" to the supported property types.
                   1487: 
                   1488: 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
                   1489:     but give a compile time error if the value is greater than 0xff.
                   1490: 
                   1491: 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
                   1492:     accidentally not being installed or uninstalled.
                   1493: 
                   1494: 25. The pcre.h file was built from pcre.h.in, but the only changes that were
                   1495:     made were to insert the current release number. This seemed silly, because
                   1496:     it made things harder for people building PCRE on systems that don't run
                   1497:     "configure". I have turned pcre.h into a distributed file, no longer built
                   1498:     by "configure", with the version identification directly included. There is
                   1499:     no longer a pcre.h.in file.
                   1500: 
                   1501:     However, this change necessitated a change to the pcre-config script as
                   1502:     well. It is built from pcre-config.in, and one of the substitutions was the
                   1503:     release number. I have updated configure.ac so that ./configure now finds
                   1504:     the release number by grepping pcre.h.
                   1505: 
                   1506: 26. Added the ability to run the tests under valgrind.
                   1507: 
                   1508: 
                   1509: Version 6.4 05-Sep-05
                   1510: ---------------------
                   1511: 
                   1512:  1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
                   1513:     "--" to be printed when multiple files were scanned, even when none of the
                   1514:     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
                   1515:     consider it to be a bug, and have restored the previous behaviour.
                   1516: 
                   1517:  2. A couple of code tidies to get rid of compiler warnings.
                   1518: 
                   1519:  3. The pcretest program used to cheat by referring to symbols in the library
                   1520:     whose names begin with _pcre_. These are internal symbols that are not
                   1521:     really supposed to be visible externally, and in some environments it is
                   1522:     possible to suppress them. The cheating is now confined to including
                   1523:     certain files from the library's source, which is a bit cleaner.
                   1524: 
                   1525:  4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
                   1526:     file's purpose clearer.
                   1527: 
                   1528:  5. Reorganized pcre_ucp_findchar().
                   1529: 
                   1530: 
                   1531: Version 6.3 15-Aug-05
                   1532: ---------------------
                   1533: 
                   1534:  1. The file libpcre.pc.in did not have general read permission in the tarball.
                   1535: 
                   1536:  2. There were some problems when building without C++ support:
                   1537: 
                   1538:     (a) If C++ support was not built, "make install" and "make test" still
                   1539:         tried to test it.
                   1540: 
                   1541:     (b) There were problems when the value of CXX was explicitly set. Some
                   1542:         changes have been made to try to fix these, and ...
                   1543: 
                   1544:     (c) --disable-cpp can now be used to explicitly disable C++ support.
                   1545: 
                   1546:     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
                   1547:         backslash in a target when C++ was disabled. This confuses some
                   1548:         versions of "make", apparently. Using an intermediate variable solves
                   1549:         this. (Same for CPP_LOBJ.)
                   1550: 
                   1551:  3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
                   1552:     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
                   1553:     necessary on certain architectures.
                   1554: 
                   1555:  4. Added a setting of -export-symbols-regex to the link command to remove
                   1556:     those symbols that are exported in the C sense, but actually are local
                   1557:     within the library, and not documented. Their names all begin with
                   1558:     "_pcre_". This is not a perfect job, because (a) we have to except some
                   1559:     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
                   1560:     available (and never for static libraries). I have made a note to try to
                   1561:     find a way round (a) in the future.
                   1562: 
                   1563: 
                   1564: Version 6.2 01-Aug-05
                   1565: ---------------------
                   1566: 
                   1567:  1. There was no test for integer overflow of quantifier values. A construction
                   1568:     such as {1111111111111111} would give undefined results. What is worse, if
                   1569:     a minimum quantifier for a parenthesized subpattern overflowed and became
                   1570:     negative, the calculation of the memory size went wrong. This could have
                   1571:     led to memory overwriting.
                   1572: 
                   1573:  2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
                   1574: 
                   1575:  3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
                   1576:     operating environments where this matters.
                   1577: 
                   1578:  4. Applied Giuseppe Maxia's patch to add additional features for controlling
                   1579:     PCRE options from within the C++ wrapper.
                   1580: 
                   1581:  5. Named capturing subpatterns were not being correctly counted when a pattern
                   1582:     was compiled. This caused two problems: (a) If there were more than 100
                   1583:     such subpatterns, the calculation of the memory needed for the whole
                   1584:     compiled pattern went wrong, leading to an overflow error. (b) Numerical
                   1585:     back references of the form \12, where the number was greater than 9, were
                   1586:     not recognized as back references, even though there were sufficient
                   1587:     previous subpatterns.
                   1588: 
                   1589:  6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
                   1590:     versions of gcc, e.g. 2.95.4.
                   1591: 
                   1592: 
                   1593: Version 6.1 21-Jun-05
                   1594: ---------------------
                   1595: 
                   1596:  1. There was one reference to the variable "posix" in pcretest.c that was not
                   1597:     surrounded by "#if !defined NOPOSIX".
                   1598: 
                   1599:  2. Make it possible to compile pcretest without DFA support, UTF8 support, or
                   1600:     the cross-check on the old pcre_info() function, for the benefit of the
                   1601:     cut-down version of PCRE that is currently imported into Exim.
                   1602: 
                   1603:  3. A (silly) pattern starting with (?i)(?-i) caused an internal space
                   1604:     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
                   1605:     patterns that start (?i) but I don't think that matters. The use of (?i) is
                   1606:     just an example; this all applies to the other options as well.
                   1607: 
                   1608:  4. Since libtool seems to echo the compile commands it is issuing, the output
                   1609:     from "make" can be reduced a bit by putting "@" in front of each libtool
                   1610:     compile command.
                   1611: 
                   1612:  5. Patch from the folks at Google for configure.in to be a bit more thorough
                   1613:     in checking for a suitable C++ installation before trying to compile the
                   1614:     C++ stuff. This should fix a reported problem when a compiler was present,
                   1615:     but no suitable headers.
                   1616: 
                   1617:  6. The man pages all had just "PCRE" as their title. I have changed them to
                   1618:     be the relevant file name. I have also arranged that these names are
                   1619:     retained in the file doc/pcre.txt, which is a concatenation in text format
                   1620:     of all the man pages except the little individual ones for each function.
                   1621: 
                   1622:  7. The NON-UNIX-USE file had not been updated for the different set of source
                   1623:     files that come with release 6. I also added a few comments about the C++
                   1624:     wrapper.
                   1625: 
                   1626: 
                   1627: Version 6.0 07-Jun-05
                   1628: ---------------------
                   1629: 
                   1630:  1. Some minor internal re-organization to help with my DFA experiments.
                   1631: 
                   1632:  2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
                   1633:     didn't matter for the library itself when fully configured, but did matter
                   1634:     when compiling without UCP support, or within Exim, where the ucp files are
                   1635:     not imported.
                   1636: 
                   1637:  3. Refactoring of the library code to split up the various functions into
                   1638:     different source modules. The addition of the new DFA matching code (see
                   1639:     below) to a single monolithic source would have made it really too
                   1640:     unwieldy, quite apart from causing all the code to be include in a
                   1641:     statically linked application, when only some functions are used. This is
                   1642:     relevant even without the DFA addition now that patterns can be compiled in
                   1643:     one application and matched in another.
                   1644: 
                   1645:     The downside of splitting up is that there have to be some external
                   1646:     functions and data tables that are used internally in different modules of
                   1647:     the library but which are not part of the API. These have all had their
                   1648:     names changed to start with "_pcre_" so that they are unlikely to clash
                   1649:     with other external names.
                   1650: 
                   1651:  4. Added an alternate matching function, pcre_dfa_exec(), which matches using
                   1652:     a different (DFA) algorithm. Although it is slower than the original
                   1653:     function, it does have some advantages for certain types of matching
                   1654:     problem.
                   1655: 
                   1656:  5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
                   1657:     including restarting after a partial match.
                   1658: 
                   1659:  6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
                   1660:     defined when compiling for Windows was sent to me. I have put it into the
                   1661:     code, though I have no means of testing or verifying it.
                   1662: 
                   1663:  7. Added the pcre_refcount() auxiliary function.
                   1664: 
                   1665:  8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
                   1666:     match before or at the first newline in the subject string. In pcretest,
                   1667:     the /f option on a pattern can be used to set this.
                   1668: 
                   1669:  9. A repeated \w when used in UTF-8 mode with characters greater than 256
                   1670:     would behave wrongly. This has been present in PCRE since release 4.0.
                   1671: 
                   1672: 10. A number of changes to the pcregrep command:
                   1673: 
                   1674:     (a) Refactored how -x works; insert ^(...)$ instead of setting
                   1675:         PCRE_ANCHORED and checking the length, in preparation for adding
                   1676:         something similar for -w.
                   1677: 
                   1678:     (b) Added the -w (match as a word) option.
                   1679: 
                   1680:     (c) Refactored the way lines are read and buffered so as to have more
                   1681:         than one at a time available.
                   1682: 
                   1683:     (d) Implemented a pcregrep test script.
                   1684: 
                   1685:     (e) Added the -M (multiline match) option. This allows patterns to match
                   1686:         over several lines of the subject. The buffering ensures that at least
                   1687:         8K, or the rest of the document (whichever is the shorter) is available
                   1688:         for matching (and similarly the previous 8K for lookbehind assertions).
                   1689: 
                   1690:     (f) Changed the --help output so that it now says
                   1691: 
                   1692:           -w, --word-regex(p)
                   1693: 
                   1694:         instead of two lines, one with "regex" and the other with "regexp"
                   1695:         because that confused at least one person since the short forms are the
                   1696:         same. (This required a bit of code, as the output is generated
                   1697:         automatically from a table. It wasn't just a text change.)
                   1698: 
                   1699:     (g) -- can be used to terminate pcregrep options if the next thing isn't an
                   1700:         option but starts with a hyphen. Could be a pattern or a path name
                   1701:         starting with a hyphen, for instance.
                   1702: 
                   1703:     (h) "-" can be given as a file name to represent stdin.
                   1704: 
                   1705:     (i) When file names are being printed, "(standard input)" is used for
                   1706:         the standard input, for compatibility with GNU grep. Previously
                   1707:         "<stdin>" was used.
                   1708: 
                   1709:     (j) The option --label=xxx can be used to supply a name to be used for
                   1710:         stdin when file names are being printed. There is no short form.
                   1711: 
                   1712:     (k) Re-factored the options decoding logic because we are going to add
                   1713:         two more options that take data. Such options can now be given in four
                   1714:         different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
                   1715: 
                   1716:     (l) Added the -A, -B, and -C options for requesting that lines of context
                   1717:         around matches be printed.
                   1718: 
                   1719:     (m) Added the -L option to print the names of files that do not contain
                   1720:         any matching lines, that is, the complement of -l.
                   1721: 
                   1722:     (n) The return code is 2 if any file cannot be opened, but pcregrep does
                   1723:         continue to scan other files.
                   1724: 
                   1725:     (o) The -s option was incorrectly implemented. For compatibility with other
                   1726:         greps, it now suppresses the error message for a non-existent or non-
                   1727:         accessible file (but not the return code). There is a new option called
                   1728:         -q that suppresses the output of matching lines, which was what -s was
                   1729:         previously doing.
                   1730: 
                   1731:     (p) Added --include and --exclude options to specify files for inclusion
                   1732:         and exclusion when recursing.
                   1733: 
                   1734: 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
                   1735:     Hopefully, it now does.
                   1736: 
                   1737: 12. Missing cast in pcre_study().
                   1738: 
                   1739: 13. Added an "uninstall" target to the makefile.
                   1740: 
                   1741: 14. Replaced "extern" in the function prototypes in Makefile.in with
                   1742:     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
                   1743:     world, but is set differently for Windows.
                   1744: 
                   1745: 15. Added a second compiling function called pcre_compile2(). The only
                   1746:     difference is that it has an extra argument, which is a pointer to an
                   1747:     integer error code. When there is a compile-time failure, this is set
                   1748:     non-zero, in addition to the error test pointer being set to point to an
                   1749:     error message. The new argument may be NULL if no error number is required
                   1750:     (but then you may as well call pcre_compile(), which is now just a
                   1751:     wrapper). This facility is provided because some applications need a
                   1752:     numeric error indication, but it has also enabled me to tidy up the way
                   1753:     compile-time errors are handled in the POSIX wrapper.
                   1754: 
                   1755: 16. Added VPATH=.libs to the makefile; this should help when building with one
                   1756:     prefix path and installing with another. (Or so I'm told by someone who
                   1757:     knows more about this stuff than I do.)
                   1758: 
                   1759: 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
                   1760:     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
                   1761:     match everything, including newlines. This is not POSIX-compatible, but
                   1762:     somebody wanted the feature. From pcretest it can be activated by using
                   1763:     both the P and the s flags.
                   1764: 
                   1765: 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
                   1766: 
                   1767: 19. libpcre.pc was being incorrectly installed as executable.
                   1768: 
                   1769: 20. A couple of places in pcretest check for end-of-line by looking for '\n';
                   1770:     it now also looks for '\r' so that it will work unmodified on Windows.
                   1771: 
                   1772: 21. Added Google's contributed C++ wrapper to the distribution.
                   1773: 
                   1774: 22. Added some untidy missing memory free() calls in pcretest, to keep
                   1775:     Electric Fence happy when testing.
                   1776: 
                   1777: 
                   1778: 
                   1779: Version 5.0 13-Sep-04
                   1780: ---------------------
                   1781: 
                   1782:  1. Internal change: literal characters are no longer packed up into items
                   1783:     containing multiple characters in a single byte-string. Each character
                   1784:     is now matched using a separate opcode. However, there may be more than one
                   1785:     byte in the character in UTF-8 mode.
                   1786: 
                   1787:  2. The pcre_callout_block structure has two new fields: pattern_position and
                   1788:     next_item_length. These contain the offset in the pattern to the next match
                   1789:     item, and its length, respectively.
                   1790: 
                   1791:  3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
                   1792:     insertion of callouts before each pattern item. Added the /C option to
                   1793:     pcretest to make use of this.
                   1794: 
                   1795:  4. On the advice of a Windows user, the lines
                   1796: 
                   1797:       #if defined(_WIN32) || defined(WIN32)
                   1798:       _setmode( _fileno( stdout ), 0x8000 );
                   1799:       #endif  /* defined(_WIN32) || defined(WIN32) */
                   1800: 
                   1801:     have been added to the source of pcretest. This apparently does useful
                   1802:     magic in relation to line terminators.
                   1803: 
                   1804:  5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
                   1805:     for the benefit of those environments where the "b" makes a difference.
                   1806: 
                   1807:  6. The icc compiler has the same options as gcc, but "configure" doesn't seem
                   1808:     to know about it. I have put a hack into configure.in that adds in code
                   1809:     to set GCC=yes if CC=icc. This seems to end up at a point in the
                   1810:     generated configure script that is early enough to affect the setting of
                   1811:     compiler options, which is what is needed, but I have no means of testing
                   1812:     whether it really works. (The user who reported this had patched the
                   1813:     generated configure script, which of course I cannot do.)
                   1814: 
                   1815:     LATER: After change 22 below (new libtool files), the configure script
                   1816:     seems to know about icc (and also ecc). Therefore, I have commented out
                   1817:     this hack in configure.in.
                   1818: 
                   1819:  7. Added support for pkg-config (2 patches were sent in).
                   1820: 
                   1821:  8. Negated POSIX character classes that used a combination of internal tables
                   1822:     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
                   1823:     [[:^ascii]]. Typically, they would match almost any characters. The other
                   1824:     POSIX classes were not broken in this way.
                   1825: 
                   1826:  9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
                   1827:     to find the match, as PCRE was deluded into thinking that the match had to
                   1828:     start at the start point or following a newline. The same bug applied to
                   1829:     patterns with negative forward assertions or any backward assertions
                   1830:     preceding ".*" at the start, unless the pattern required a fixed first
                   1831:     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
                   1832: 
                   1833: 10. In UTF-8 mode, when moving forwards in the subject after a failed match
                   1834:     starting at the last subject character, bytes beyond the end of the subject
                   1835:     string were read.
                   1836: 
                   1837: 11. Renamed the variable "class" as "classbits" to make life easier for C++
                   1838:     users. (Previously there was a macro definition, but it apparently wasn't
                   1839:     enough.)
                   1840: 
                   1841: 12. Added the new field "tables" to the extra data so that tables can be passed
                   1842:     in at exec time, or the internal tables can be re-selected. This allows
                   1843:     a compiled regex to be saved and re-used at a later time by a different
                   1844:     program that might have everything at different addresses.
                   1845: 
                   1846: 13. Modified the pcre-config script so that, when run on Solaris, it shows a
                   1847:     -R library as well as a -L library.
                   1848: 
                   1849: 14. The debugging options of pcretest (-d on the command line or D on a
                   1850:     pattern) showed incorrect output for anything following an extended class
                   1851:     that contained multibyte characters and which was followed by a quantifier.
                   1852: 
                   1853: 15. Added optional support for general category Unicode character properties
                   1854:     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
                   1855:     support. It adds about 90K to the size of the library. The meanings of the
                   1856:     inbuilt class escapes such as \d and \s have NOT been changed.
                   1857: 
                   1858: 16. Updated pcredemo.c to include calls to free() to release the memory for the
                   1859:     compiled pattern.
                   1860: 
                   1861: 17. The generated file chartables.c was being created in the source directory
                   1862:     instead of in the building directory. This caused the build to fail if the
                   1863:     source directory was different from the building directory, and was
                   1864:     read-only.
                   1865: 
                   1866: 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
                   1867:     file. No doubt somebody will tell me if they don't make sense... Also added
                   1868:     Dan Mooney's comments about building on OpenVMS.
                   1869: 
                   1870: 19. Added support for partial matching via the PCRE_PARTIAL option for
                   1871:     pcre_exec() and the \P data escape in pcretest.
                   1872: 
                   1873: 20. Extended pcretest with 3 new pattern features:
                   1874: 
                   1875:     (i)   A pattern option of the form ">rest-of-line" causes pcretest to
                   1876:           write the compiled pattern to the file whose name is "rest-of-line".
                   1877:           This is a straight binary dump of the data, with the saved pointer to
                   1878:           the character tables forced to be NULL. The study data, if any, is
                   1879:           written too. After writing, pcretest reads a new pattern.
                   1880: 
                   1881:     (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
                   1882:           compiled pattern from the given file. There must not be any
                   1883:           occurrences of "<" in the file name (pretty unlikely); if there are,
                   1884:           pcretest will instead treat the initial "<" as a pattern delimiter.
                   1885:           After reading in the pattern, pcretest goes on to read data lines as
                   1886:           usual.
                   1887: 
                   1888:     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
                   1889:           and 16-bit fields in a compiled pattern, to simulate a pattern that
                   1890:           was compiled on a host of opposite endianness.
                   1891: 
                   1892: 21. The pcre-exec() function can now cope with patterns that were compiled on
                   1893:     hosts of opposite endianness, with this restriction:
                   1894: 
                   1895:       As for any compiled expression that is saved and used later, the tables
                   1896:       pointer field cannot be preserved; the extra_data field in the arguments
                   1897:       to pcre_exec() should be used to pass in a tables address if a value
                   1898:       other than the default internal tables were used at compile time.
                   1899: 
                   1900: 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
                   1901:     now diagnosed as an error. Previously, most of the time, a negative number
                   1902:     would have been treated as zero, but if in addition "ovector" was passed as
                   1903:     NULL, a crash could occur.
                   1904: 
                   1905: 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
                   1906:     new versions from the libtool 1.5 distribution (the last one is a copy of
                   1907:     a file called libtool.m4). This seems to have fixed the need to patch
                   1908:     "configure" to support Darwin 1.3 (which I used to do). However, I still
                   1909:     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
                   1910:     workstation).
                   1911: 
                   1912: 24. Changed the PCRE licence to be the more standard "BSD" licence.
                   1913: 
                   1914: 
                   1915: Version 4.5 01-Dec-03
                   1916: ---------------------
                   1917: 
                   1918:  1. There has been some re-arrangement of the code for the match() function so
                   1919:     that it can be compiled in a version that does not call itself recursively.
                   1920:     Instead, it keeps those local variables that need separate instances for
                   1921:     each "recursion" in a frame on the heap, and gets/frees frames whenever it
                   1922:     needs to "recurse". Keeping track of where control must go is done by means
                   1923:     of setjmp/longjmp. The whole thing is implemented by a set of macros that
                   1924:     hide most of the details from the main code, and operates only if
                   1925:     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
                   1926:     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
                   1927:     operating.
                   1928: 
                   1929:     To make it easier for callers to provide specially tailored get/free
                   1930:     functions for this usage, two new functions, pcre_stack_malloc, and
                   1931:     pcre_stack_free, are used. They are always called in strict stacking order,
                   1932:     and the size of block requested is always the same.
                   1933: 
                   1934:     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
                   1935:     PCRE has been compiled to use the stack or the heap for recursion. The
                   1936:     -C option of pcretest uses this to show which version is compiled.
                   1937: 
                   1938:     A new data escape \S, is added to pcretest; it causes the amounts of store
                   1939:     obtained and freed by both kinds of malloc/free at match time to be added
                   1940:     to the output.
                   1941: 
                   1942:  2. Changed the locale test to use "fr_FR" instead of "fr" because that's
                   1943:     what's available on my current Linux desktop machine.
                   1944: 
                   1945:  3. When matching a UTF-8 string, the test for a valid string at the start has
                   1946:     been extended. If start_offset is not zero, PCRE now checks that it points
                   1947:     to a byte that is the start of a UTF-8 character. If not, it returns
                   1948:     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
                   1949:     this is necessary because there may be backward assertions in the pattern.
                   1950:     When matching the same subject several times, it may save resources to use
                   1951:     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
                   1952: 
                   1953:  4. The code for checking the validity of UTF-8 strings has been tightened so
                   1954:     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
                   1955:     containing "overlong sequences".
                   1956: 
                   1957:  5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
                   1958:     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
                   1959:     should have been "&", but it just so happened that all the cases this let
                   1960:     through by mistake were picked up later in the function.
                   1961: 
                   1962:  6. I had used a variable called "isblank" - this is a C99 function, causing
                   1963:     some compilers to warn. To avoid this, I renamed it (as "blankclass").
                   1964: 
                   1965:  7. Cosmetic: (a) only output another newline at the end of pcretest if it is
                   1966:     prompting; (b) run "./pcretest /dev/null" at the start of the test script
                   1967:     so the version is shown; (c) stop "make test" echoing "./RunTest".
                   1968: 
                   1969:  8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
                   1970: 
                   1971:  9. The prototype for memmove() for systems that don't have it was using
                   1972:     size_t, but the inclusion of the header that defines size_t was later. I've
                   1973:     moved the #includes for the C headers earlier to avoid this.
                   1974: 
                   1975: 10. Added some adjustments to the code to make it easier to compiler on certain
                   1976:     special systems:
                   1977: 
                   1978:       (a) Some "const" qualifiers were missing.
                   1979:       (b) Added the macro EXPORT before all exported functions; by default this
                   1980:           is defined to be empty.
                   1981:       (c) Changed the dftables auxiliary program (that builds chartables.c) so
                   1982:           that it reads its output file name as an argument instead of writing
                   1983:           to the standard output and assuming this can be redirected.
                   1984: 
                   1985: 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
                   1986:     class containing characters with values greater than 255, PCRE compilation
                   1987:     went into a loop.
                   1988: 
                   1989: 12. A recursive reference to a subpattern that was within another subpattern
                   1990:     that had a minimum quantifier of zero caused PCRE to crash. For example,
                   1991:     (x(y(?2))z)? provoked this bug with a subject that got as far as the
                   1992:     recursion. If the recursively-called subpattern itself had a zero repeat,
                   1993:     that was OK.
                   1994: 
                   1995: 13. In pcretest, the buffer for reading a data line was set at 30K, but the
                   1996:     buffer into which it was copied (for escape processing) was still set at
                   1997:     1024, so long lines caused crashes.
                   1998: 
                   1999: 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
                   2000:     "internal error: code overflow...". This applied to any character class
                   2001:     that was followed by a possessive quantifier.
                   2002: 
                   2003: 15. Modified the Makefile to add libpcre.la as a prerequisite for
                   2004:     libpcreposix.la because I was told this is needed for a parallel build to
                   2005:     work.
                   2006: 
                   2007: 16. If a pattern that contained .* following optional items at the start was
                   2008:     studied, the wrong optimizing data was generated, leading to matching
                   2009:     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
                   2010:     matching string must start with a or b or c. The correct conclusion for
                   2011:     this pattern is that a match can start with any character.
                   2012: 
                   2013: 
                   2014: Version 4.4 13-Aug-03
                   2015: ---------------------
                   2016: 
                   2017:  1. In UTF-8 mode, a character class containing characters with values between
                   2018:     127 and 255 was not handled correctly if the compiled pattern was studied.
                   2019:     In fixing this, I have also improved the studying algorithm for such
                   2020:     classes (slightly).
                   2021: 
                   2022:  2. Three internal functions had redundant arguments passed to them. Removal
                   2023:     might give a very teeny performance improvement.
                   2024: 
                   2025:  3. Documentation bug: the value of the capture_top field in a callout is *one
                   2026:     more than* the number of the hightest numbered captured substring.
                   2027: 
                   2028:  4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
                   2029:     in incorrectly linking with a previously installed version. They now link
                   2030:     explicitly with libpcre.la.
                   2031: 
                   2032:  5. configure.in no longer needs to recognize Cygwin specially.
                   2033: 
                   2034:  6. A problem in pcre.in for Windows platforms is fixed.
                   2035: 
                   2036:  7. If a pattern was successfully studied, and the -d (or /D) flag was given to
                   2037:     pcretest, it used to include the size of the study block as part of its
                   2038:     output. Unfortunately, the structure contains a field that has a different
                   2039:     size on different hardware architectures. This meant that the tests that
                   2040:     showed this size failed. As the block is currently always of a fixed size,
                   2041:     this information isn't actually particularly useful in pcretest output, so
                   2042:     I have just removed it.
                   2043: 
                   2044:  8. Three pre-processor statements accidentally did not start in column 1.
                   2045:     Sadly, there are *still* compilers around that complain, even though
                   2046:     standard C has not required this for well over a decade. Sigh.
                   2047: 
                   2048:  9. In pcretest, the code for checking callouts passed small integers in the
                   2049:     callout_data field, which is a void * field. However, some picky compilers
                   2050:     complained about the casts involved for this on 64-bit systems. Now
                   2051:     pcretest passes the address of the small integer instead, which should get
                   2052:     rid of the warnings.
                   2053: 
                   2054: 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
                   2055:     both compile and run time, and gives an error if an invalid UTF-8 sequence
                   2056:     is found. There is a option for disabling this check in cases where the
                   2057:     string is known to be correct and/or the maximum performance is wanted.
                   2058: 
                   2059: 11. In response to a bug report, I changed one line in Makefile.in from
                   2060: 
                   2061:         -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
                   2062:     to
                   2063:         -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
                   2064: 
                   2065:     to look similar to other lines, but I have no way of telling whether this
                   2066:     is the right thing to do, as I do not use Windows. No doubt I'll get told
                   2067:     if it's wrong...
                   2068: 
                   2069: 
                   2070: Version 4.3 21-May-03
                   2071: ---------------------
                   2072: 
                   2073: 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
                   2074:    Makefile.
                   2075: 
                   2076: 2. Some refactoring to improve the quality of the code:
                   2077: 
                   2078:    (i)   The utf8_table... variables are now declared "const".
                   2079: 
                   2080:    (ii)  The code for \cx, which used the "case flipping" table to upper case
                   2081:          lower case letters, now just substracts 32. This is ASCII-specific,
                   2082:          but the whole concept of \cx is ASCII-specific, so it seems
                   2083:          reasonable.
                   2084: 
                   2085:    (iii) PCRE was using its character types table to recognize decimal and
                   2086:          hexadecimal digits in the pattern. This is silly, because it handles
                   2087:          only 0-9, a-f, and A-F, but the character types table is locale-
                   2088:          specific, which means strange things might happen. A private
                   2089:          table is now used for this - though it costs 256 bytes, a table is
                   2090:          much faster than multiple explicit tests. Of course, the standard
                   2091:          character types table is still used for matching digits in subject
                   2092:          strings against \d.
                   2093: 
                   2094:    (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
                   2095:          ending in _t are). So I've renamed it as ESC_tee.
                   2096: 
                   2097: 3. The first argument for regexec() in the POSIX wrapper should have been
                   2098:    defined as "const".
                   2099: 
                   2100: 4. Changed pcretest to use malloc() for its buffers so that they can be
                   2101:    Electric Fenced for debugging.
                   2102: 
                   2103: 5. There were several places in the code where, in UTF-8 mode, PCRE would try
                   2104:    to read one or more bytes before the start of the subject string. Often this
                   2105:    had no effect on PCRE's behaviour, but in some circumstances it could
                   2106:    provoke a segmentation fault.
                   2107: 
                   2108: 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
                   2109:    to try to read one or more bytes before the start of the subject string.
                   2110: 
                   2111: 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
                   2112:    UTF-8 support could misbehave in various ways if the subject string
                   2113:    contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
                   2114:    area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
                   2115:    back over UTF-8 characters.)
                   2116: 
                   2117: 
                   2118: Version 4.2 14-Apr-03
                   2119: ---------------------
                   2120: 
                   2121: 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
                   2122: 
                   2123: 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
                   2124:      [ON_WINDOWS]: new variable, "#" on non-Windows platforms
                   2125:      [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
                   2126:      [WIN_PREFIX]: new variable, "cyg" for Cygwin
                   2127:      * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
                   2128:        and BUILD_EXEEXT
                   2129:      Note: automatic setting of the BUILD variables is not yet working
                   2130:      set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
                   2131:        compile-time but not at link-time
                   2132:      [LINK]: use for linking executables only
                   2133:      make different versions for Windows and non-Windows
                   2134:      [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
                   2135:        libraries
                   2136:      [LINK_FOR_BUILD]: new variable
                   2137:      [OBJEXT]: use throughout
                   2138:      [EXEEXT]: use throughout
                   2139:      <winshared>: new target
                   2140:      <wininstall>: new target
                   2141:      <dftables.o>: use native compiler
                   2142:      <dftables>: use native linker
                   2143:      <install>: handle Windows platform correctly
                   2144:      <clean>: ditto
                   2145:      <check>: ditto
                   2146:      copy DLL to top builddir before testing
                   2147: 
                   2148:    As part of these changes, -no-undefined was removed again. This was reported
                   2149:    to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
                   2150:    in any case.
                   2151: 
                   2152: 3. Some tidies to get rid of compiler warnings:
                   2153: 
                   2154:    . In the match_data structure, match_limit was an unsigned long int, whereas
                   2155:      match_call_count was an int. I've made them both unsigned long ints.
                   2156: 
                   2157:    . In pcretest the fact that a const uschar * doesn't automatically cast to
                   2158:      a void * provoked a warning.
                   2159: 
                   2160:    . Turning on some more compiler warnings threw up some "shadow" variables
                   2161:      and a few more missing casts.
                   2162: 
                   2163: 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
                   2164:    option, a class that contained a single character with a value between 128
                   2165:    and 255 (e.g. /[\xFF]/) caused PCRE to crash.
                   2166: 
                   2167: 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
                   2168:    option, a class that contained several characters, but with at least one
                   2169:    whose value was between 128 and 255 caused PCRE to crash.
                   2170: 
                   2171: 
                   2172: Version 4.1 12-Mar-03
                   2173: ---------------------
                   2174: 
                   2175: 1. Compiling with gcc -pedantic found a couple of places where casts were
                   2176: needed, and a string in dftables.c that was longer than standard compilers are
                   2177: required to support.
                   2178: 
                   2179: 2. Compiling with Sun's compiler found a few more places where the code could
                   2180: be tidied up in order to avoid warnings.
                   2181: 
                   2182: 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
                   2183: first of these names is deprecated in the latest Autoconf in favour of the name
                   2184: CC_FOR_BUILD, because "host" is typically used to mean the system on which the
                   2185: compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
                   2186: analogy I have changed it to CFLAGS_FOR_BUILD.
                   2187: 
                   2188: 4. Added -no-undefined to the linking command in the Makefile, because this is
                   2189: apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
                   2190: linking step for the pcreposix library.
                   2191: 
                   2192: 5. PCRE was failing to diagnose the case of two named groups with the same
                   2193: name.
                   2194: 
                   2195: 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
                   2196: literal character that is needed in the subject for a match, and scans along to
                   2197: ensure that it is present before embarking on the full matching process. This
                   2198: saves time in cases of nested unlimited repeats that are never going to match.
                   2199: Problem: the scan can take a lot of time if the subject is very long (e.g.
                   2200: megabytes), thus penalizing straightforward matches. It is now done only if the
                   2201: amount of subject to be scanned is less than 1000 bytes.
                   2202: 
                   2203: 7. A lesser problem with the same optimization is that it was recording the
                   2204: first character of an anchored pattern as "needed", thus provoking a search
                   2205: right along the subject, even when the first match of the pattern was going to
                   2206: fail. The "needed" character is now not set for anchored patterns, unless it
                   2207: follows something in the pattern that is of non-fixed length. Thus, it still
                   2208: fulfils its original purpose of finding quick non-matches in cases of nested
                   2209: unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
                   2210: 
                   2211: 
                   2212: Version 4.0 17-Feb-03
                   2213: ---------------------
                   2214: 
                   2215: 1. If a comment in an extended regex that started immediately after a meta-item
                   2216: extended to the end of string, PCRE compiled incorrect data. This could lead to
                   2217: all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
                   2218: 
                   2219: 2. Moved to autoconf 2.53 and libtool 1.4.2.
                   2220: 
                   2221: 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
                   2222: the special perltest8 script is no longer needed - all the tests can be run
                   2223: from a single perltest script.
                   2224: 
                   2225: 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
                   2226: by \s. It has now been removed in PCRE. This means it isn't recognized as
                   2227: whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
                   2228: class [:space:] *does* include VT, thereby creating a mess.
                   2229: 
                   2230: 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
                   2231: space and tab.
                   2232: 
                   2233: 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
                   2234: its new features into the main test script, reducing the number of scripts.
                   2235: 
                   2236: 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
                   2237: were backward compatible, and made the (?i) apply to the whole pattern, as if
                   2238: /i were given. Now it behaves more logically, and applies the option setting
                   2239: only to what follows. PCRE has been changed to follow suit. However, if it
                   2240: finds options settings right at the start of the pattern, it extracts them into
                   2241: the global options, as before. Thus, they show up in the info data.
                   2242: 
                   2243: 8. Added support for the \Q...\E escape sequence. Characters in between are
                   2244: treated as literals. This is slightly different from Perl in that $ and @ are
                   2245: also handled as literals inside the quotes. In Perl, they will cause variable
                   2246: interpolation. Note the following examples:
                   2247: 
                   2248:     Pattern            PCRE matches      Perl matches
                   2249: 
                   2250:     \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
                   2251:     \Qabc\$xyz\E       abc\$xyz          abc\$xyz
                   2252:     \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
                   2253: 
                   2254: For compatibility with Perl, \Q...\E sequences are recognized inside character
                   2255: classes as well as outside them.
                   2256: 
                   2257: 9. Re-organized 3 code statements in pcretest to avoid "overflow in
                   2258: floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
                   2259: (size_t) cast to one statement in pcretest and one in pcreposix to avoid
                   2260: signed/unsigned warnings.
                   2261: 
                   2262: 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
                   2263: option for pcretest, so I've replaced it by a simple function that does just
                   2264: that job.
                   2265: 
                   2266: 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
                   2267: "pcregrep -".
                   2268: 
                   2269: 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
                   2270: Java package. This provides some syntactic sugar for simple cases of what my
                   2271: documentation calls "once-only subpatterns". A pattern such as x*+ is the same
                   2272: as (?>x*). In other words, if what is inside (?>...) is just a single repeated
                   2273: item, you can use this simplified notation. Note that only makes sense with
                   2274: greedy quantifiers. Consequently, the use of the possessive quantifier forces
                   2275: greediness, whatever the setting of the PCRE_UNGREEDY option.
                   2276: 
                   2277: 13. A change of greediness default within a pattern was not taking effect at
                   2278: the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
                   2279: subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
                   2280: was abstracted outside.
                   2281: 
                   2282: 14. PCRE now supports the \G assertion. It is true when the current matching
                   2283: position is at the start point of the match. This differs from \A when the
                   2284: starting offset is non-zero. Used with the /g option of pcretest (or similar
                   2285: code), it works in the same way as it does for Perl's /g option. If all
                   2286: alternatives of a regex begin with \G, the expression is anchored to the start
                   2287: match position, and the "anchored" flag is set in the compiled expression.
                   2288: 
                   2289: 15. Some bugs concerning the handling of certain option changes within patterns
                   2290: have been fixed. These applied to options other than (?ims). For example,
                   2291: "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
                   2292: been the other way round. Some of this was related to change 7 above.
                   2293: 
                   2294: 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
                   2295: features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
                   2296: and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
                   2297: POSIX classes only within a class (e.g. /[[:alpha:]]/).
                   2298: 
                   2299: 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
                   2300: mode. Unlike ".", it always matches newline, whatever the setting of
                   2301: PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
                   2302: assertions. Perl allows it, but it doesn't (in general) work because it can't
                   2303: calculate the length of the lookbehind. At least, that's the case for Perl
                   2304: 5.8.0 - I've been told they are going to document that it doesn't work in
                   2305: future.
                   2306: 
                   2307: 18. Added an error diagnosis for escapes that PCRE does not support: these are
                   2308: \L, \l, \N, \P, \p, \U, \u, and \X.
                   2309: 
                   2310: 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
                   2311: reading past the end of the pattern in cases such as /[abcd/.
                   2312: 
                   2313: 20. PCRE was getting more memory than necessary for patterns with classes that
                   2314: contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
                   2315: 
                   2316: 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
                   2317: compiling PCRE for use with Virtual Pascal.
                   2318: 
                   2319: 22. Small fix to the Makefile to make it work properly if the build is done
                   2320: outside the source tree.
                   2321: 
                   2322: 23. Added a new extension: a condition to go with recursion. If a conditional
                   2323: subpattern starts with (?(R) the "true" branch is used if recursion has
                   2324: happened, whereas the "false" branch is used only at the top level.
                   2325: 
                   2326: 24. When there was a very long string of literal characters (over 255 bytes
                   2327: without UTF support, over 250 bytes with UTF support), the computation of how
                   2328: much memory was required could be incorrect, leading to segfaults or other
                   2329: strange effects.
                   2330: 
                   2331: 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
                   2332: start of line for a non-DOTALL pattern) when a pattern started with (.*) and
                   2333: there was a subsequent back reference to those brackets. This meant that, for
                   2334: example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
                   2335: possible to check for precisely this case. All we can do is abandon the
                   2336: optimization if .* occurs inside capturing brackets when there are any back
                   2337: references whatsoever. (See below for a better fix that came later.)
                   2338: 
                   2339: 26. The handling of the optimization for finding the first character of a
                   2340: non-anchored pattern, and for finding a character that is required later in the
                   2341: match were failing in some cases. This didn't break the matching; it just
                   2342: failed to optimize when it could. The way this is done has been re-implemented.
                   2343: 
                   2344: 27. Fixed typo in error message for invalid (?R item (it said "(?p").
                   2345: 
                   2346: 28. Added a new feature that provides some of the functionality that Perl
                   2347: provides with (?{...}). The facility is termed a "callout". The way it is done
                   2348: in PCRE is for the caller to provide an optional function, by setting
                   2349: pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
                   2350: global variable. By default it is unset, which disables all calling out. To get
                   2351: the function called, the regex must include (?C) at appropriate points. This
                   2352: is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
                   2353: This provides a means of identifying different callout points. When PCRE
                   2354: reaches such a point in the regex, if pcre_callout has been set, the external
                   2355: function is called. It is provided with data in a structure called
                   2356: pcre_callout_block, which is defined in pcre.h. If the function returns 0,
                   2357: matching continues; if it returns a non-zero value, the match at the current
                   2358: point fails. However, backtracking will occur if possible. [This was changed
                   2359: later and other features added - see item 49 below.]
                   2360: 
                   2361: 29. pcretest is upgraded to test the callout functionality. It provides a
                   2362: callout function that displays information. By default, it shows the start of
                   2363: the match and the current position in the text. There are some new data escapes
                   2364: to vary what happens:
                   2365: 
                   2366:     \C+         in addition, show current contents of captured substrings
                   2367:     \C-         do not supply a callout function
                   2368:     \C!n        return 1 when callout number n is reached
                   2369:     \C!n!m      return 1 when callout number n is reached for the mth time
                   2370: 
                   2371: 30. If pcregrep was called with the -l option and just a single file name, it
                   2372: output "<stdin>" if a match was found, instead of the file name.
                   2373: 
                   2374: 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
                   2375: slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
                   2376: pcre_exec(). This saves a malloc/free per call. The default value of
                   2377: POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
                   2378: when configuring.
                   2379: 
                   2380: 32. The default maximum size of a compiled pattern is 64K. There have been a
                   2381: few cases of people hitting this limit. The code now uses macros to handle the
                   2382: storing of links as offsets within the compiled pattern. It defaults to 2-byte
                   2383: links, but this can be changed to 3 or 4 bytes by --with-link-size when
                   2384: configuring. Tests 2 and 5 work only with 2-byte links because they output
                   2385: debugging information about compiled patterns.
                   2386: 
                   2387: 33. Internal code re-arrangements:
                   2388: 
                   2389: (a) Moved the debugging function for printing out a compiled regex into
                   2390:     its own source file (printint.c) and used #include to pull it into
                   2391:     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
                   2392:     separate copies.
                   2393: 
                   2394: (b) Defined the list of op-code names for debugging as a macro in
                   2395:     internal.h so that it is next to the definition of the opcodes.
                   2396: 
                   2397: (c) Defined a table of op-code lengths for simpler skipping along compiled
                   2398:     code. This is again a macro in internal.h so that it is next to the
                   2399:     definition of the opcodes.
                   2400: 
                   2401: 34. Added support for recursive calls to individual subpatterns, along the
                   2402: lines of Robin Houston's patch (but implemented somewhat differently).
                   2403: 
                   2404: 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
                   2405: allow it to read and process whole directories in Win32. This code was
                   2406: contributed by Lionel Fourquaux; it has not been tested by me.
                   2407: 
                   2408: 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
                   2409: used to name a group. Names consist of alphanumerics and underscores, and must
                   2410: be unique. Back references use the syntax (?P=name) and recursive calls use
                   2411: (?P>name) which is a PCRE extension to the Python extension. Groups still have
                   2412: numbers. The function pcre_fullinfo() can be used after compilation to extract
                   2413: a name/number map. There are three relevant calls:
                   2414: 
                   2415:   PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
                   2416:   PCRE_INFO_NAMECOUNT            yields the number of entries
                   2417:   PCRE_INFO_NAMETABLE            yields a pointer to the map.
                   2418: 
                   2419: The map is a vector of fixed-size entries. The size of each entry depends on
                   2420: the length of the longest name used. The first two bytes of each entry are the
                   2421: group number, most significant byte first. There follows the corresponding
                   2422: name, zero terminated. The names are in alphabetical order.
                   2423: 
                   2424: 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
                   2425: case instead of 255. Making it the same both with and without UTF-8 support
                   2426: means that the same test output works with both.
                   2427: 
                   2428: 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
                   2429: calling malloc() with a zero argument.
                   2430: 
                   2431: 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
                   2432: optimization. I've improved things by keeping a bitmap of backreferences with
                   2433: numbers 1-31 so that if .* occurs inside capturing brackets that are not in
                   2434: fact referenced, the optimization can be applied. It is unlikely that a
                   2435: relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
                   2436: the match to follow \n) will appear inside brackets with a number greater than
                   2437: 31, but if it does, any back reference > 31 suppresses the optimization.
                   2438: 
                   2439: 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
                   2440: of disabling numbered capturing parentheses. Any opening parenthesis that is
                   2441: not followed by ? behaves as if it were followed by ?: but named parentheses
                   2442: can still be used for capturing (and they will acquire numbers in the usual
                   2443: way).
                   2444: 
                   2445: 41. Redesigned the return codes from the match() function into yes/no/error so
                   2446: that errors can be passed back from deep inside the nested calls. A malloc
                   2447: failure while inside a recursive subpattern call now causes the
                   2448: PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
                   2449: 
                   2450: 42. It is now possible to set a limit on the number of times the match()
                   2451: function is called in a call to pcre_exec(). This facility makes it possible to
                   2452: limit the amount of recursion and backtracking, though not in a directly
                   2453: obvious way, because the match() function is used in a number of different
                   2454: circumstances. The count starts from zero for each position in the subject
                   2455: string (for non-anchored patterns). The default limit is, for compatibility, a
                   2456: large number, namely 10 000 000. You can change this in two ways:
                   2457: 
                   2458: (a) When configuring PCRE before making, you can use --with-match-limit=n
                   2459:     to set a default value for the compiled library.
                   2460: 
                   2461: (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
                   2462:     a different value is set. See 45 below.
                   2463: 
                   2464: If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
                   2465: 
                   2466: 43. Added a new function pcre_config(int, void *) to enable run-time extraction
                   2467: of things that can be changed at compile time. The first argument specifies
                   2468: what is wanted and the second points to where the information is to be placed.
                   2469: The current list of available information is:
                   2470: 
                   2471:   PCRE_CONFIG_UTF8
                   2472: 
                   2473: The output is an integer that is set to one if UTF-8 support is available;
                   2474: otherwise it is set to zero.
                   2475: 
                   2476:   PCRE_CONFIG_NEWLINE
                   2477: 
                   2478: The output is an integer that it set to the value of the code that is used for
                   2479: newline. It is either LF (10) or CR (13).
                   2480: 
                   2481:   PCRE_CONFIG_LINK_SIZE
                   2482: 
                   2483: The output is an integer that contains the number of bytes used for internal
                   2484: linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
                   2485: 
                   2486:   PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
                   2487: 
                   2488: The output is an integer that contains the threshold above which the POSIX
                   2489: interface uses malloc() for output vectors. See item 31 above.
                   2490: 
                   2491:   PCRE_CONFIG_MATCH_LIMIT
                   2492: 
                   2493: The output is an unsigned integer that contains the default limit of the number
                   2494: of match() calls in a pcre_exec() execution. See 42 above.
                   2495: 
                   2496: 44. pcretest has been upgraded by the addition of the -C option. This causes it
                   2497: to extract all the available output from the new pcre_config() function, and to
                   2498: output it. The program then exits immediately.
                   2499: 
                   2500: 45. A need has arisen to pass over additional data with calls to pcre_exec() in
                   2501: order to support additional features. One way would have been to define
                   2502: pcre_exec2() (for example) with extra arguments, but this would not have been
                   2503: extensible, and would also have required all calls to the original function to
                   2504: be mapped to the new one. Instead, I have chosen to extend the mechanism that
                   2505: is used for passing in "extra" data from pcre_study().
                   2506: 
                   2507: The pcre_extra structure is now exposed and defined in pcre.h. It currently
                   2508: contains the following fields:
                   2509: 
                   2510:   flags         a bitmap indicating which of the following fields are set
                   2511:   study_data    opaque data from pcre_study()
                   2512:   match_limit   a way of specifying a limit on match() calls for a specific
                   2513:                   call to pcre_exec()
                   2514:   callout_data  data for callouts (see 49 below)
                   2515: 
                   2516: The flag bits are also defined in pcre.h, and are
                   2517: 
                   2518:   PCRE_EXTRA_STUDY_DATA
                   2519:   PCRE_EXTRA_MATCH_LIMIT
                   2520:   PCRE_EXTRA_CALLOUT_DATA
                   2521: 
                   2522: The pcre_study() function now returns one of these new pcre_extra blocks, with
                   2523: the actual study data pointed to by the study_data field, and the
                   2524: PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
                   2525: before. That is, this change is entirely upwards-compatible and requires no
                   2526: change to existing code.
                   2527: 
                   2528: If you want to pass in additional data to pcre_exec(), you can either place it
                   2529: in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
                   2530: block.
                   2531: 
                   2532: 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
                   2533: data string contains the escape sequence \M, pcretest calls pcre_exec() several
                   2534: times with different match limits, until it finds the minimum value needed for
                   2535: pcre_exec() to complete. The value is then output. This can be instructive; for
                   2536: most simple matches the number is quite small, but for pathological cases it
                   2537: gets very large very quickly.
                   2538: 
                   2539: 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
                   2540: returns the size of the data block pointed to by the study_data field in a
                   2541: pcre_extra block, that is, the value that was passed as the argument to
                   2542: pcre_malloc() when PCRE was getting memory in which to place the information
                   2543: created by pcre_study(). The fourth argument should point to a size_t variable.
                   2544: pcretest has been extended so that this information is shown after a successful
                   2545: pcre_study() call when information about the compiled regex is being displayed.
                   2546: 
                   2547: 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
                   2548: because what follows is always an absolute path. (Later: it turns out that this
                   2549: is more than cosmetic for MinGW, because it doesn't like empty path
                   2550: components.)
                   2551: 
                   2552: 49. Some changes have been made to the callout feature (see 28 above):
                   2553: 
                   2554: (i)  A callout function now has three choices for what it returns:
                   2555: 
                   2556:        0  =>  success, carry on matching
                   2557:      > 0  =>  failure at this point, but backtrack if possible
                   2558:      < 0  =>  serious error, return this value from pcre_exec()
                   2559: 
                   2560:      Negative values should normally be chosen from the set of PCRE_ERROR_xxx
                   2561:      values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
                   2562:      "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
                   2563:      use by callout functions. It will never be used by PCRE itself.
                   2564: 
                   2565: (ii) The pcre_extra structure (see 45 above) has a void * field called
                   2566:      callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
                   2567:      pcre_callout_block structure has a field of the same name. The contents of
                   2568:      the field passed in the pcre_extra structure are passed to the callout
                   2569:      function in the corresponding field in the callout block. This makes it
                   2570:      easier to use the same callout-containing regex from multiple threads. For
                   2571:      testing, the pcretest program has a new data escape
                   2572: 
                   2573:        \C*n        pass the number n (may be negative) as callout_data
                   2574: 
                   2575:      If the callout function in pcretest receives a non-zero value as
                   2576:      callout_data, it returns that value.
                   2577: 
                   2578: 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
                   2579: there were some redundant $(CFLAGS) in commands that are now specified as
                   2580: $(LINK), which already includes $(CFLAGS).
                   2581: 
                   2582: 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
                   2583: has been compiled with UTF-8 support *and* pcre_compile() has been compiled
                   2584: with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
                   2585: one-byte characters throughout. Note that case-insensitive matching applies
                   2586: only to characters whose values are less than 256. PCRE doesn't support the
                   2587: notion of cases for higher-valued characters.
                   2588: 
                   2589: (i)   A character class whose characters are all within 0-255 is handled as
                   2590:       a bit map, and the map is inverted for negative classes. Previously, a
                   2591:       character > 255 always failed to match such a class; however it should
                   2592:       match if the class was a negative one (e.g. [^ab]). This has been fixed.
                   2593: 
                   2594: (ii)  A negated character class with a single character < 255 is coded as
                   2595:       "not this character" (OP_NOT). This wasn't working properly when the test
                   2596:       character was multibyte, either singly or repeated.
                   2597: 
                   2598: (iii) Repeats of multibyte characters are now handled correctly in UTF-8
                   2599:       mode, for example: \x{100}{2,3}.
                   2600: 
                   2601: (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
                   2602:       singly or repeated) now correctly test multibyte characters. However,
                   2603:       PCRE doesn't recognize any characters with values greater than 255 as
                   2604:       digits, spaces, or word characters. Such characters always match \D, \S,
                   2605:       and \W, and never match \d, \s, or \w.
                   2606: 
                   2607: (v)   Classes may now contain characters and character ranges with values
                   2608:       greater than 255. For example: [ab\x{100}-\x{400}].
                   2609: 
                   2610: (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
                   2611:       PCRE in UTF-8 mode.
                   2612: 
                   2613: 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
                   2614: PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
                   2615: retained for backwards compatibility. (Note that LASTLITERAL is also a byte
                   2616: value.)
                   2617: 
                   2618: 53. The single man page has become too large. I have therefore split it up into
                   2619: a number of separate man pages. These also give rise to individual HTML pages;
                   2620: these are now put in a separate directory, and there is an index.html page that
                   2621: lists them all. Some hyperlinking between the pages has been installed.
                   2622: 
                   2623: 54. Added convenience functions for handling named capturing parentheses.
                   2624: 
                   2625: 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
                   2626: aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
                   2627: true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
                   2628: are faulted.
                   2629: 
                   2630: 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
                   2631: calling configure. These values are used when compiling the dftables.c program
                   2632: which is run to generate the source of the default character tables. They
                   2633: default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
                   2634: you will need to set these values.
                   2635: 
                   2636: 57. Updated the building process for Windows DLL, as provided by Fred Cox.
                   2637: 
                   2638: 
                   2639: Version 3.9 02-Jan-02
                   2640: ---------------------
                   2641: 
                   2642: 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
                   2643: 
                   2644: 2. If --disable-static was given, the building process failed when trying to
                   2645: build pcretest and pcregrep. (For some reason it was using libtool to compile
                   2646: them, which is not right, as they aren't part of the library.)
                   2647: 
                   2648: 
                   2649: Version 3.8 18-Dec-01
                   2650: ---------------------
                   2651: 
                   2652: 1. The experimental UTF-8 code was completely screwed up. It was packing the
                   2653: bytes in the wrong order. How dumb can you get?
                   2654: 
                   2655: 
                   2656: Version 3.7 29-Oct-01
                   2657: ---------------------
                   2658: 
                   2659: 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
                   2660: This caused pcretest, when used on the test data, to segfault. Unfortunately,
                   2661: this didn't happen under Solaris 8, where I normally test things.
                   2662: 
                   2663: 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
                   2664: doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
                   2665: isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
                   2666: this fix an hour or so after the initial 3.7 release.)
                   2667: 
                   2668: 
                   2669: Version 3.6 23-Oct-01
                   2670: ---------------------
                   2671: 
                   2672: 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
                   2673: offsets passed as NULL with zero offset count.
                   2674: 
                   2675: 2. The config.guess and config.sub files had not been updated when I moved to
                   2676: the latest autoconf.
                   2677: 
                   2678: 
                   2679: Version 3.5 15-Aug-01
                   2680: ---------------------
                   2681: 
                   2682: 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
                   2683: had been forgotten.
                   2684: 
                   2685: 2. By using declared but undefined structures, we can avoid using "void"
                   2686: definitions in pcre.h while keeping the internal definitions of the structures
                   2687: private.
                   2688: 
                   2689: 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
                   2690: user point of view, this means that both static and shared libraries are built
                   2691: by default, but this can be individually controlled. More of the work of
                   2692: handling this static/shared cases is now inside libtool instead of PCRE's make
                   2693: file.
                   2694: 
                   2695: 4. The pcretest utility is now installed along with pcregrep because it is
                   2696: useful for users (to test regexs) and by doing this, it automatically gets
                   2697: relinked by libtool. The documentation has been turned into a man page, so
                   2698: there are now .1, .txt, and .html versions in /doc.
                   2699: 
                   2700: 5. Upgrades to pcregrep:
                   2701:    (i)   Added long-form option names like gnu grep.
                   2702:    (ii)  Added --help to list all options with an explanatory phrase.
                   2703:    (iii) Added -r, --recursive to recurse into sub-directories.
                   2704:    (iv)  Added -f, --file to read patterns from a file.
                   2705: 
                   2706: 6. pcre_exec() was referring to its "code" argument before testing that
                   2707: argument for NULL (and giving an error if it was NULL).
                   2708: 
                   2709: 7. Upgraded Makefile.in to allow for compiling in a different directory from
                   2710: the source directory.
                   2711: 
                   2712: 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
                   2713: options bits, the pointer it was passed was to an int instead of to an unsigned
                   2714: long int. This mattered only on 64-bit systems.
                   2715: 
                   2716: 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
                   2717: generated) instead of pcre.in, which it its source. Also made the same change
                   2718: in several of the .c files.
                   2719: 
                   2720: 10. A new release of gcc defines printf() as a macro, which broke pcretest
                   2721: because it had an ifdef in the middle of a string argument for printf(). Fixed
                   2722: by using separate calls to printf().
                   2723: 
                   2724: 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
                   2725: script, to force use of CR or LF instead of \n in the source. On non-Unix
                   2726: systems, the value can be set in config.h.
                   2727: 
                   2728: 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
                   2729: absolute limit. Changed the text of the error message to make this clear, and
                   2730: likewise updated the man page.
                   2731: 
                   2732: 13. The limit of 99 on the number of capturing subpatterns has been removed.
                   2733: The new limit is 65535, which I hope will not be a "real" limit.
                   2734: 
                   2735: 
                   2736: Version 3.4 22-Aug-00
                   2737: ---------------------
                   2738: 
                   2739: 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
                   2740: 
                   2741: 2. Diagnose condition (?(0) as an error instead of crashing on matching.
                   2742: 
                   2743: 
                   2744: Version 3.3 01-Aug-00
                   2745: ---------------------
                   2746: 
                   2747: 1. If an octal character was given, but the value was greater than \377, it
                   2748: was not getting masked to the least significant bits, as documented. This could
                   2749: lead to crashes in some systems.
                   2750: 
                   2751: 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
                   2752: the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
                   2753: 
                   2754: 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
                   2755: These just pass their arguments on to (pcre_free)(), but they are provided
                   2756: because some uses of PCRE bind it to non-C systems that can call its functions,
                   2757: but cannot call free() or pcre_free() directly.
                   2758: 
                   2759: 4. Add "make test" as a synonym for "make check". Corrected some comments in
                   2760: the Makefile.
                   2761: 
                   2762: 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
                   2763: Makefile.
                   2764: 
                   2765: 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
                   2766: command called pgrep for grepping around the active processes.
                   2767: 
                   2768: 7. Added the beginnings of support for UTF-8 character strings.
                   2769: 
                   2770: 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
                   2771: RANLIB to ./ltconfig so that they are used by libtool. I think these are all
                   2772: the relevant ones. (AR is not passed because ./ltconfig does its own figuring
                   2773: out for the ar command.)
                   2774: 
                   2775: 
                   2776: Version 3.2 12-May-00
                   2777: ---------------------
                   2778: 
                   2779: This is purely a bug fixing release.
                   2780: 
                   2781: 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
                   2782: of ZA. This was just one example of several cases that could provoke this bug,
                   2783: which was introduced by change 9 of version 2.00. The code for breaking
                   2784: infinite loops after an iteration that matches an empty string was't working
                   2785: correctly.
                   2786: 
                   2787: 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
                   2788: when matched against abbab (for example). After matching an empty string, it
                   2789: wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
                   2790: caused it to match further down the string than it should.
                   2791: 
                   2792: 3. The code contained an inclusion of sys/types.h. It isn't clear why this
                   2793: was there because it doesn't seem to be needed, and it causes trouble on some
                   2794: systems, as it is not a Standard C header. It has been removed.
                   2795: 
                   2796: 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
                   2797: were reported on the Macintosh. The changes were from
                   2798: 
                   2799:   while ((c = *(++ptr)) != 0 && c != '\n');
                   2800: to
                   2801:   while ((c = *(++ptr)) != 0 && c != '\n') ;
                   2802: 
                   2803: Totally extraordinary, but if that's what it takes...
                   2804: 
                   2805: 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
                   2806: available. Added HAVE_BCOPY and an autoconf test for it; if neither
                   2807: HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
                   2808: assumes the way PCRE uses memmove() (always moving upwards).
                   2809: 
                   2810: 6. PCRE is being used in one environment where strchr() is not available. There
                   2811: was only one use in pcre.c, and writing it out to avoid strchr() probably gives
                   2812: faster code anyway.
                   2813: 
                   2814: 
                   2815: Version 3.1 09-Feb-00
                   2816: ---------------------
                   2817: 
                   2818: The only change in this release is the fixing of some bugs in Makefile.in for
                   2819: the "install" target:
                   2820: 
                   2821: (1) It was failing to install pcreposix.h.
                   2822: 
                   2823: (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
                   2824: 
                   2825: 
                   2826: Version 3.0 01-Feb-00
                   2827: ---------------------
                   2828: 
                   2829: 1. Add support for the /+ modifier to perltest (to output $` like it does in
                   2830: pcretest).
                   2831: 
                   2832: 2. Add support for the /g modifier to perltest.
                   2833: 
                   2834: 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
                   2835: matches null strings.
                   2836: 
                   2837: 4. Fix perltest so that it doesn't do unwanted things when fed an empty
                   2838: pattern. Perl treats empty patterns specially - it reuses the most recent
                   2839: pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
                   2840: effect.
                   2841: 
                   2842: 5. The POSIX interface was broken in that it was just handing over the POSIX
                   2843: captured string vector to pcre_exec(), but (since release 2.00) PCRE has
                   2844: required a bigger vector, with some working space on the end. This means that
                   2845: the POSIX wrapper now has to get and free some memory, and copy the results.
                   2846: 
                   2847: 6. Added some simple autoconf support, placing the test data and the
                   2848: documentation in separate directories, re-organizing some of the
                   2849: information files, and making it build pcre-config (a GNU standard). Also added
                   2850: libtool support for building PCRE as a shared library, which is now the
                   2851: default.
                   2852: 
                   2853: 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
                   2854: 09 are not valid octal constants. Single digits will be used for minor values
                   2855: less than 10.
                   2856: 
                   2857: 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
                   2858: existing programs that set these in the POSIX interface can use PCRE without
                   2859: modification.
                   2860: 
                   2861: 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
                   2862: return all that pcre_info() returns, plus additional data. The pcre_info()
                   2863: function is retained for compatibility, but is considered to be obsolete.
                   2864: 
                   2865: 10. Added experimental recursion feature (?R) to handle one common case that
                   2866: Perl 5.6 will be able to do with (?p{...}).
                   2867: 
                   2868: 11. Added support for POSIX character classes like [:alpha:], which Perl is
                   2869: adopting.
                   2870: 
                   2871: 
                   2872: Version 2.08 31-Aug-99
                   2873: ----------------------
                   2874: 
                   2875: 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
                   2876: trying to match at the startoffset position, but instead was moving forward to
                   2877: the next newline as if a previous match had failed.
                   2878: 
                   2879: 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
                   2880: and could get into a loop if a null string was matched other than at the start
                   2881: of the subject.
                   2882: 
                   2883: 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
                   2884: be distinguished at compile time, and for completeness also added PCRE_DATE.
                   2885: 
                   2886: 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
                   2887: in GnuWin32 environments.
                   2888: 
                   2889: 
                   2890: Version 2.07 29-Jul-99
                   2891: ----------------------
                   2892: 
                   2893: 1. The documentation is now supplied in plain text form and HTML as well as in
                   2894: the form of man page sources.
                   2895: 
                   2896: 2. C++ compilers don't like assigning (void *) values to other pointer types.
                   2897: In particular this affects malloc(). Although there is no problem in Standard
                   2898: C, I've put in casts to keep C++ compilers happy.
                   2899: 
                   2900: 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
                   2901: should be (const char *).
                   2902: 
                   2903: 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
                   2904: be useful for non-Unix systems who don't want to bother with the POSIX stuff.
                   2905: However, I haven't made this a standard facility. The documentation doesn't
                   2906: mention it, and the Makefile doesn't support it.
                   2907: 
                   2908: 5. The Makefile now contains an "install" target, with editable destinations at
                   2909: the top of the file. The pcretest program is not installed.
                   2910: 
                   2911: 6. pgrep -V now gives the PCRE version number and date.
                   2912: 
                   2913: 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
                   2914: causing the entire string to be ignored, instead of just the last character.
                   2915: 
                   2916: 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
                   2917: non-matching string, it can take a very, very long time, even for strings of
                   2918: quite modest length, because of the nested recursion. PCRE now does better in
                   2919: some of these cases. It does this by remembering the last required literal
                   2920: character in the pattern, and pre-searching the subject to ensure it is present
                   2921: before running the real match. In other words, it applies a heuristic to detect
                   2922: some types of certain failure quickly, and in the above example, if presented
                   2923: with a string that has no trailing " it gives "no match" very quickly.
                   2924: 
                   2925: 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
                   2926: other alternatives are tried instead.
                   2927: 
                   2928: 
                   2929: Version 2.06 09-Jun-99
                   2930: ----------------------
                   2931: 
                   2932: 1. Change pcretest's output for amount of store used to show just the code
                   2933: space, because the remainder (the data block) varies in size between 32-bit and
                   2934: 64-bit systems.
                   2935: 
                   2936: 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
                   2937: start matching at. This allows lookbehinds to work when searching for multiple
                   2938: occurrences in a string.
                   2939: 
                   2940: 3. Added additional options to pcretest for testing multiple occurrences:
                   2941: 
                   2942:    /+   outputs the rest of the string that follows a match
                   2943:    /g   loops for multiple occurrences, using the new startoffset argument
                   2944:    /G   loops for multiple occurrences by passing an incremented pointer
                   2945: 
                   2946: 4. PCRE wasn't doing the "first character" optimization for patterns starting
                   2947: with \b or \B, though it was doing it for other lookbehind assertions. That is,
                   2948: it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
                   2949: the letter 'x'. On long subject strings, this gives a significant speed-up.
                   2950: 
                   2951: 
                   2952: Version 2.05 21-Apr-99
                   2953: ----------------------
                   2954: 
                   2955: 1. Changed the type of magic_number from int to long int so that it works
                   2956: properly on 16-bit systems.
                   2957: 
                   2958: 2. Fixed a bug which caused patterns starting with .* not to work correctly
                   2959: when the subject string contained newline characters. PCRE was assuming
                   2960: anchoring for such patterns in all cases, which is not correct because .* will
                   2961: not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
                   2962: DOTALL is set at top level; otherwise it knows that patterns starting with .*
                   2963: must be retried after every newline in the subject.
                   2964: 
                   2965: 
                   2966: Version 2.04 18-Feb-99
                   2967: ----------------------
                   2968: 
                   2969: 1. For parenthesized subpatterns with repeats whose minimum was zero, the
                   2970: computation of the store needed to hold the pattern was incorrect (too large).
                   2971: If such patterns were nested a few deep, this could multiply and become a real
                   2972: problem.
                   2973: 
                   2974: 2. Added /M option to pcretest to show the memory requirement of a specific
                   2975: pattern. Made -m a synonym of -s (which does this globally) for compatibility.
                   2976: 
                   2977: 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
                   2978: compiled in such a way that the backtracking after subsequent failure was
                   2979: pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
                   2980: ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
                   2981: 
                   2982: 
                   2983: Version 2.03 02-Feb-99
                   2984: ----------------------
                   2985: 
                   2986: 1. Fixed typo and small mistake in man page.
                   2987: 
                   2988: 2. Added 4th condition (GPL supersedes if conflict) and created separate
                   2989: LICENCE file containing the conditions.
                   2990: 
                   2991: 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
                   2992: Perl, that is the internal \ allows the delimiter to be included in the
                   2993: pattern. Locked out the use of \ as a delimiter. If \ immediately follows
                   2994: the final delimiter, add \ to the end of the pattern (to test the error).
                   2995: 
                   2996: 4. Added the convenience functions for extracting substrings after a successful
                   2997: match. Updated pcretest to make it able to test these functions.
                   2998: 
                   2999: 
                   3000: Version 2.02 14-Jan-99
                   3001: ----------------------
                   3002: 
                   3003: 1. Initialized the working variables associated with each extraction so that
                   3004: their saving and restoring doesn't refer to uninitialized store.
                   3005: 
                   3006: 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
                   3007: compiler for OS/2 into generating correct code. Apparently IBM isn't going to
                   3008: fix the problem.
                   3009: 
                   3010: 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
                   3011: calls, and wasn't printing the correct value for compiling calls. Increased the
                   3012: default value of LOOPREPEAT, and the number of significant figures in the
                   3013: times.
                   3014: 
                   3015: 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
                   3016: 
                   3017: 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
                   3018: a building problem on Windows NT with a FAT file system.
                   3019: 
                   3020: 
                   3021: Version 2.01 21-Oct-98
                   3022: ----------------------
                   3023: 
                   3024: 1. Changed the API for pcre_compile() to allow for the provision of a pointer
                   3025: to character tables built by pcre_maketables() in the current locale. If NULL
                   3026: is passed, the default tables are used.
                   3027: 
                   3028: 
                   3029: Version 2.00 24-Sep-98
                   3030: ----------------------
                   3031: 
                   3032: 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
                   3033: it any more.
                   3034: 
                   3035: 2. Allow quantification of (?>) groups, and make it work correctly.
                   3036: 
                   3037: 3. The first character computation wasn't working for (?>) groups.
                   3038: 
                   3039: 4. Correct the implementation of \Z (it is permitted to match on the \n at the
                   3040: end of the subject) and add 5.005's \z, which really does match only at the
                   3041: very end of the subject.
                   3042: 
                   3043: 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
                   3044: 
                   3045: 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
                   3046: DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
                   3047: localized options. All options to pcre_study() were also removed.
                   3048: 
                   3049: 7. Add other new features from 5.005:
                   3050: 
                   3051:    $(?<=           positive lookbehind
                   3052:    $(?<!           negative lookbehind
                   3053:    (?imsx-imsx)    added the unsetting capability
                   3054:                    such a setting is global if at outer level; local otherwise
                   3055:    (?imsx-imsx:)   non-capturing groups with option setting
                   3056:    (?(cond)re|re)  conditional pattern matching
                   3057: 
                   3058:    A backreference to itself in a repeated group matches the previous
                   3059:    captured string.
                   3060: 
                   3061: 8. General tidying up of studying (both automatic and via "study")
                   3062: consequential on the addition of new assertions.
                   3063: 
                   3064: 9. As in 5.005, unlimited repeated groups that could match an empty substring
                   3065: are no longer faulted at compile time. Instead, the loop is forcibly broken at
                   3066: runtime if any iteration does actually match an empty substring.
                   3067: 
                   3068: 10. Include the RunTest script in the distribution.
                   3069: 
                   3070: 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
                   3071: discrepancies, some of which were old and were also with respect to 5.004. They
                   3072: have now been fixed.
                   3073: 
                   3074: 
                   3075: Version 1.09 28-Apr-98
                   3076: ----------------------
                   3077: 
                   3078: 1. A negated single character class followed by a quantifier with a minimum
                   3079: value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
                   3080: program crashes, or just wrong answers. This did not apply to negated classes
                   3081: containing more than one character, or to minima other than one.
                   3082: 
                   3083: 
                   3084: Version 1.08 27-Mar-98
                   3085: ----------------------
                   3086: 
                   3087: 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
                   3088: 
                   3089: 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
                   3090: latter must appear before anything that relies on it in the pattern.
                   3091: 
                   3092: 
                   3093: Version 1.07 16-Feb-98
                   3094: ----------------------
                   3095: 
                   3096: 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
                   3097: repeat of a potentially empty string).
                   3098: 
                   3099: 
                   3100: Version 1.06 23-Jan-98
                   3101: ----------------------
                   3102: 
                   3103: 1. Added Markus Oberhumer's little patches for C++.
                   3104: 
                   3105: 2. Literal strings longer than 255 characters were broken.
                   3106: 
                   3107: 
                   3108: Version 1.05 23-Dec-97
                   3109: ----------------------
                   3110: 
                   3111: 1. Negated character classes containing more than one character were failing if
                   3112: PCRE_CASELESS was set at run time.
                   3113: 
                   3114: 
                   3115: Version 1.04 19-Dec-97
                   3116: ----------------------
                   3117: 
                   3118: 1. Corrected the man page, where some "const" qualifiers had been omitted.
                   3119: 
                   3120: 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
                   3121: input syntax.
                   3122: 
                   3123: 3. Fixed memory leak which occurred when a regex with back references was
                   3124: matched with an offsets vector that wasn't big enough. The temporary memory
                   3125: that is used in this case wasn't being freed if the match failed.
                   3126: 
                   3127: 4. Tidied pcretest to ensure it frees memory that it gets.
                   3128: 
                   3129: 5. Temporary memory was being obtained in the case where the passed offsets
                   3130: vector was exactly big enough.
                   3131: 
                   3132: 6. Corrected definition of offsetof() from change 5 below.
                   3133: 
                   3134: 7. I had screwed up change 6 below and broken the rules for the use of
                   3135: setjmp(). Now fixed.
                   3136: 
                   3137: 
                   3138: Version 1.03 18-Dec-97
                   3139: ----------------------
                   3140: 
                   3141: 1. A erroneous regex with a missing opening parenthesis was correctly
                   3142: diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
                   3143: on some systems.
                   3144: 
                   3145: 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
                   3146: it was reported that one broken compiler failed on the former because "code" is
                   3147: also an independent variable.
                   3148: 
                   3149: 3. The erroneous regex a[]b caused an array overrun reference.
                   3150: 
                   3151: 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
                   3152: fail on data ending with that character. (It was going on too far, and checking
                   3153: the next character, typically a binary zero.) This was specific to the
                   3154: optimized code for single-character negative classes.
                   3155: 
                   3156: 5. Added a contributed patch from the TIN world which does the following:
                   3157: 
                   3158:   + Add an undef for memmove, in case the the system defines a macro for it.
                   3159: 
                   3160:   + Add a definition of offsetof(), in case there isn't one. (I don't know
                   3161:     the reason behind this - offsetof() is part of the ANSI standard - but
                   3162:     it does no harm).
                   3163: 
                   3164:   + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
                   3165:     most of the places where whitespace preceded '#'. I have given up and
                   3166:     allowed the remaining 2 cases to be at the margin.
                   3167: 
                   3168:   + Rename some variables in pcre to eliminate shadowing. This seems very
                   3169:     pedantic, but does no harm, of course.
                   3170: 
                   3171: 6. Moved the call to setjmp() into its own function, to get rid of warnings
                   3172: from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
                   3173: 
                   3174: 7. Constructs such as \d{8,} were compiling into the equivalent of
                   3175: \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
                   3176: outcome, but in this particular case used more store than had been allocated,
                   3177: which caused the bug to be discovered because it threw up an internal error.
                   3178: 
                   3179: 8. The debugging code in both pcre and pcretest for outputting the compiled
                   3180: form of a regex was going wrong in the case of back references followed by
                   3181: curly-bracketed repeats.
                   3182: 
                   3183: 
                   3184: Version 1.02 12-Dec-97
                   3185: ----------------------
                   3186: 
                   3187: 1. Typos in pcre.3 and comments in the source fixed.
                   3188: 
                   3189: 2. Applied a contributed patch to get rid of places where it used to remove
                   3190: 'const' from variables, and fixed some signed/unsigned and uninitialized
                   3191: variable warnings.
                   3192: 
                   3193: 3. Added the "runtest" target to Makefile.
                   3194: 
                   3195: 4. Set default compiler flag to -O2 rather than just -O.
                   3196: 
                   3197: 
                   3198: Version 1.01 19-Nov-97
                   3199: ----------------------
                   3200: 
                   3201: 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
                   3202: like /([ab]*)*/, that is, for classes with more than one character in them.
                   3203: 
                   3204: 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
                   3205: as /((?>a*))*/ (a PCRE_EXTRA facility).
                   3206: 
                   3207: 
                   3208: Version 1.00 18-Nov-97
                   3209: ----------------------
                   3210: 
                   3211: 1. Added compile-time macros to support systems such as SunOS4 which don't have
                   3212: memmove() or strerror() but have other things that can be used instead.
                   3213: 
                   3214: 2. Arranged that "make clean" removes the executables.
                   3215: 
                   3216: 
                   3217: Version 0.99 27-Oct-97
                   3218: ----------------------
                   3219: 
                   3220: 1. Fixed bug in code for optimizing classes with only one character. It was
                   3221: initializing a 32-byte map regardless, which could cause it to run off the end
                   3222: of the memory it had got.
                   3223: 
                   3224: 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
                   3225: 
                   3226: 
                   3227: Version 0.98 22-Oct-97
                   3228: ----------------------
                   3229: 
                   3230: 1. Fixed bug in code for handling temporary memory usage when there are more
                   3231: back references than supplied space in the ovector. This could cause segfaults.
                   3232: 
                   3233: 
                   3234: Version 0.97 21-Oct-97
                   3235: ----------------------
                   3236: 
                   3237: 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
                   3238: 
                   3239: 2. Optimized negated single characters not to use a bit map.
                   3240: 
                   3241: 3. Brought error texts together as macro definitions; clarified some of them;
                   3242: fixed one that was wrong - it said "range out of order" when it meant "invalid
                   3243: escape sequence".
                   3244: 
                   3245: 4. Changed some char * arguments to const char *.
                   3246: 
                   3247: 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
                   3248: 
                   3249: 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
                   3250: pcretest.
                   3251: 
                   3252: 
                   3253: Version 0.96 16-Oct-97
                   3254: ----------------------
                   3255: 
                   3256: 1. Added a simple "pgrep" utility to the distribution.
                   3257: 
                   3258: 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
                   3259: unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
                   3260: where "ddd" means "one or more decimal digits".
                   3261: 
                   3262: 3. Fixed serious bug. If a pattern had a back reference, but the call to
                   3263: pcre_exec() didn't supply a large enough ovector to record the related
                   3264: identifying subpattern, the match always failed. PCRE now remembers the number
                   3265: of the largest back reference, and gets some temporary memory in which to save
                   3266: the offsets during matching if necessary, in order to ensure that
                   3267: backreferences always work.
                   3268: 
                   3269: 4. Increased the compatibility with Perl in a number of ways:
                   3270: 
                   3271:   (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
                   3272:       to request this handling. The option can be set at compile or exec time.
                   3273: 
                   3274:   (b) $ matches before a terminating newline by default; an option
                   3275:       PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
                   3276:       mode). The option can be set at compile or exec time.
                   3277: 
                   3278:   (c) The handling of \ followed by a digit other than 0 is now supposed to be
                   3279:       the same as Perl's. If the decimal number it represents is less than 10
                   3280:       or there aren't that many previous left capturing parentheses, an octal
                   3281:       escape is read. Inside a character class, it's always an octal escape,
                   3282:       even if it is a single digit.
                   3283: 
                   3284:   (d) An escaped but undefined alphabetic character is taken as a literal,
                   3285:       unless PCRE_EXTRA is set. Currently this just reserves the remaining
                   3286:       escapes.
                   3287: 
                   3288:   (e) {0} is now permitted. (The previous item is removed from the compiled
                   3289:       pattern).
                   3290: 
                   3291: 5. Changed all the names of code files so that the basic parts are no longer
                   3292: than 10 characters, and abolished the teeny "globals.c" file.
                   3293: 
                   3294: 6. Changed the handling of character classes; they are now done with a 32-byte
                   3295: bit map always.
                   3296: 
                   3297: 7. Added the -d and /D options to pcretest to make it possible to look at the
                   3298: internals of compilation without having to recompile pcre.
                   3299: 
                   3300: 
                   3301: Version 0.95 23-Sep-97
                   3302: ----------------------
                   3303: 
                   3304: 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
                   3305: \x20 at the start of a run of normal characters. These were being treated as
                   3306: real characters, instead of the source characters being re-checked.
                   3307: 
                   3308: 
                   3309: Version 0.94 18-Sep-97
                   3310: ----------------------
                   3311: 
                   3312: 1. The functions are now thread-safe, with the caveat that the global variables
                   3313: containing pointers to malloc() and free() or alternative functions are the
                   3314: same for all threads.
                   3315: 
                   3316: 2. Get pcre_study() to generate a bitmap of initial characters for non-
                   3317: anchored patterns when this is possible, and use it if passed to pcre_exec().
                   3318: 
                   3319: 
                   3320: Version 0.93 15-Sep-97
                   3321: ----------------------
                   3322: 
                   3323: 1. /(b)|(:+)/ was computing an incorrect first character.
                   3324: 
                   3325: 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
                   3326: but not actually doing anything yet.
                   3327: 
                   3328: 3. Treat "-" characters in classes that cannot be part of ranges as literals,
                   3329: as Perl does (e.g. [-az] or [az-]).
                   3330: 
                   3331: 4. Set the anchored flag if a branch starts with .* or .*? because that tests
                   3332: all possible positions.
                   3333: 
                   3334: 5. Split up into different modules to avoid including unneeded functions in a
                   3335: compiled binary. However, compile and exec are still in one module. The "study"
                   3336: function is split off.
                   3337: 
                   3338: 6. The character tables are now in a separate module whose source is generated
                   3339: by an auxiliary program - but can then be edited by hand if required. There are
                   3340: now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
                   3341: toupper() in the code.
                   3342: 
                   3343: 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
                   3344: make them global. Abolish the function for setting them, as the caller can now
                   3345: set them directly.
                   3346: 
                   3347: 
                   3348: Version 0.92 11-Sep-97
                   3349: ----------------------
                   3350: 
                   3351: 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
                   3352: (e.g. /a{1,3}/) was broken (I mis-optimized it).
                   3353: 
                   3354: 2. Caseless matching was not working in character classes if the characters in
                   3355: the pattern were in upper case.
                   3356: 
                   3357: 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
                   3358: 
                   3359: 4. Make PCRE_ANCHORED public and accept as a compile option.
                   3360: 
                   3361: 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
                   3362: PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
                   3363: pass them.
                   3364: 
                   3365: 6. Give an error if bad option bits passed at compile or run time.
                   3366: 
                   3367: 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
                   3368: pcretest to cause it to pass that flag.
                   3369: 
                   3370: 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
                   3371: options, and the first character, if set.
                   3372: 
                   3373: 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
                   3374: 
                   3375: 
                   3376: Version 0.91 10-Sep-97
                   3377: ----------------------
                   3378: 
                   3379: 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
                   3380: match the empty string as in /(a*)*/. It was looping and ultimately crashing.
                   3381: 
                   3382: 2. PCRE was looping on encountering an indefinitely repeated back reference to
                   3383: a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
                   3384: Perl does - treats the match as successful.
                   3385: 
                   3386: ****

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