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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-07  Version 8.32
5    ------------
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
10    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11        Patch by Daniel Richard G.
13    3.  Single character iterator optimizations in the JIT compiler.
15    4.  Improved JIT compiler optimizations for character ranges.
17    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18        Reported by Giuseppe D'Angelo.
20    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21        of a line, was being set incorrectly in cases where .* appeared inside
22        atomic brackets at the start of a pattern, or where there was a subsequent
23        *PRUNE or *SKIP.
25    7.  Improved instruction cache flush for POWER/PowerPC.
26        Patch by Daniel Richard G.
28    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
29        grep:
31        (a) There is now no limit to the number of patterns to be matched.
33        (b) An error is given if a pattern is too long.
35        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
36            are now supported.
38        (d) --exclude-from and --include-from (multiple use) have been added.
40        (e) Exclusions and inclusions now apply to all files and directories, not
41            just to those obtained from scanning a directory recursively.
43        (f) Multiple uses of -f and --file-list are now supported.
45        (g) In a Windows environment, the default for -d has been changed from
46            "read" (the GNU grep default) to "skip", because otherwise the presence
47            of a directory in the file list provokes an error.
49        (h) The documentation has been revised and clarified in places.
51    9.  Improve the matching speed of capturing brackets.
53    10. Changed the meaning of \X so that it now matches a Unicode extended
54        grapheme cluster.
56    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
57        out POSIX threads when JIT support is configured.
59    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
61    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
62        structure could go wrong in environments where size_t is not the same size
63        as int.
65    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
66        set.
68    15. The EBCDIC support had decayed; later updates to the code had included
69        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
70        general tidy up of EBCDIC-related issues, and the documentation was also
71        not quite right. There is now a test that can be run on ASCII systems to
72        check some of the EBCDIC-related things (but is it not a full test).
74    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
75        in a small tidy to the code.
77    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
79    18. If the --only-matching (-o) option in pcregrep is specified multiple
80        times, each one causes appropriate output. For example, -o1 -o2 outputs the
81        substrings matched by the 1st and 2nd capturing parentheses. A separating
82        string can be specified by --om-separator (default empty).
84    19. Improving the first n character searches.
86    20. Turn case lists for horizontal and vertical white space into macros so that
87        they are defined only once.
89    21. This set of changes together give more compatible Unicode case-folding
90        behaviour for characters that have more than one other case when UCP
91        support is available.
93        (a) The Unicode property table now has offsets into a new table of sets of
94            three or more characters that are case-equivalent. The MultiStage2.py
95            script that generates these tables (the pcre_ucd.c file) now scans
96            CaseFolding.txt instead of UnicodeData.txt for character case
97            information.
99        (b) The code for adding characters or ranges of characters to a character
100            class has been abstracted into a generalized function that also handles
101            case-independence. In UTF-mode with UCP support, this uses the new data
102            to handle characters with more than one other case.
104        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
105            whose other case is greater than 256 are now correctly matched
106            caselessly. Previously, the high codepoint matched the low one, but not
107            vice versa.
109        (d) The processing of \h, \H, \v, and \ in character classes now makes use
110            of the new class addition function, using character lists defined as
111            macros alongside the case definitions of 20 above.
113        (e) Caseless back references now work with characters that have more than
114            one other case.
116        (f) General caseless matching of characters with more than one other case
117            is supported.
119    22. Unicode character properties were updated from Unicode 6.2.0
121    23. Improved CMake support under Windows. Patch by Daniel Richard G.
123    24. Add support for 32-bit character strings, and UTF-32
125    25. Major JIT compiler update (code refactoring and bugfixing).
126        Experimental Sparc 32 support is added.
128    26. Applied a modified version of Daniel Richard G's patch to create
129        pcre.h.generic and config.h.generic by "make" instead of in the
130        PrepareRelease script.
132    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
133        pcre_compile.c when checking for a zero character.
135    28. Introducing a native interface for JIT. Through this interface, the compiled
136        machine code can be directly executed. The purpose of this interface is to
137        provide fast pattern matching, so several sanity checks are not performed.
138        However, feature tests are still performed. The new interface provides
139        1.4x speedup compared to the old one.
142    Version 8.31 06-July-2012
143    -------------------------
145    1.  Fixing a wrong JIT test case and some compiler warnings.
147    2.  Removed a bashism from the RunTest script.
149    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
150        to unsigned type, result still unsigned" that was given by an MS compiler
151        on encountering the code "-sizeof(xxx)".
153    4.  Partial matching support is added to the JIT compiler.
155    5.  Fixed several bugs concerned with partial matching of items that consist
156        of more than one character:
158        (a) /^(..)\1/ did not partially match "aba" because checking references was
159            done on an "all or nothing" basis. This also applied to repeated
160            references.
162        (b) \R did not give a hard partial match if \r was found at the end of the
163            subject.
165        (c) \X did not give a hard partial match after matching one or more
166            characters at the end of the subject.
168        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
169            a partial match for the string "\r".
171        (e) When newline was set to CRLF, the metacharacter "." did not recognize
172            a partial match for a CR character at the end of the subject string.
174    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
175        running pcretest, the text "(JIT)" added to the output whenever JIT is
176        actually used to run the match.
178    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
179        or /S+[+] with a digit between 1 and 7.
181    8.  OP_NOT now supports any UTF character not just single-byte ones.
183    9.  (*MARK) control verb is now supported by the JIT compiler.
185    10. The command "./RunTest list" lists the available tests without actually
186        running any of them. (Because I keep forgetting what they all are.)
190    12. Applied a (slightly modified) user-supplied patch that improves performance
191        when the heap is used for recursion (compiled with --disable-stack-for-
192        recursion). Instead of malloc and free for each heap frame each time a
193        logical recursion happens, frames are retained on a chain and re-used where
194        possible. This sometimes gives as much as 30% improvement.
196    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
197        call.
199    14. As documented, (*COMMIT) is now confined to within a positive assertion.
201    15. It is now possible to link pcretest with libedit as an alternative to
202        libreadline.
204    16. (*COMMIT) control verb is now supported by the JIT compiler.
206    17. The Unicode data tables have been updated to Unicode 6.1.0.
208    18. Added --file-list option to pcregrep.
210    19. Added binary file support to pcregrep, including the -a, --binary-files,
211        -I, and --text options.
213    20. The madvise function is renamed for posix_madvise for QNX compatibility
214        reasons. Fixed by Giuseppe D'Angelo.
216    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
218    22. Changed the option for creating symbolic links for 16-bit man pages from
219        -s to -sf so that re-installing does not cause issues.
221    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
223    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
224        matches in certain environments (the workspace was not being correctly
225        retained). Also added to pcre_dfa_exec() a simple plausibility check on
226        some of the workspace data at the beginning of a restart.
228    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
229        was not doing so when it should - probably a typo introduced by SVN 528
230        (change 8.10/14).
232    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
233        \w+ when the character tables indicated that \x{c4} was a word character.
234        There were several related cases, all because the tests for doing a table
235        lookup were testing for characters less than 127 instead of 255.
237    27. If a pattern contains capturing parentheses that are not used in a match,
238        their slots in the ovector are set to -1. For those that are higher than
239        any matched groups, this happens at the end of processing. In the case when
240        there were back references that the ovector was too small to contain
241        (causing temporary malloc'd memory to be used during matching), and the
242        highest capturing number was not used, memory off the end of the ovector
243        was incorrectly being set to -1. (It was using the size of the temporary
244        memory instead of the true size.)
246    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
247        ovector size, it uses memory at the end of the block that it has got.
249    29. Check for an overlong MARK name and give an error at compile time. The
250        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
252    30. JIT compiler update.
254    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
255        Rill for the patch.
257    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
259    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
261    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
262        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
263        was enabled.
265    35. Improve JIT code generation for greedy plus quantifier.
267    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
268        1 to "aa" instead of to an empty string. The bug affected repeated groups
269        that could potentially match an empty string.
271    37. Optimizing single character iterators in JIT.
273    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
274        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
275        codepoints that are too big for the mode are faulted, and in a UTF mode,
276        disallowed codepoints are also faulted.
278    39. If PCRE was compiled with UTF support, in three places in the DFA
279        matcher there was code that should only have been obeyed in UTF mode, but
280        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
281        processing when bytes with values greater than 127 were present. In 16-bit
282        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
283        both cases the values are those that cannot be the first data item in a UTF
284        character. The three items that might have provoked this were recursions,
285        possessively repeated groups, and atomic groups.
287    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
288        and pcregrep, because some OS require shared objects to be explicitly
289        passed to ld, causing the link step to fail if they are not.
291    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
292        mode, patterns that started with \h* or \R* might be incorrectly matched.
295    Version 8.30 04-February-2012
296    -----------------------------
298    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
299        name is defined in ctype.h.
301    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
302        only in quite long subpatterns.
304    3.  Removed the function pcre_info(), which has been obsolete and deprecated
305        since it was replaced by pcre_fullinfo() in February 2000.
307    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
308        match a (*MARK), and the match failed at the start of the subject, a
309        reference to memory before the start of the subject could occur. This bug
310        was introduced by fix 17 of release 8.21.
312    5.  A reference to an unset group with zero minimum repetition was giving
313        totally wrong answers (in non-JavaScript-compatibility mode). For example,
314        /(another)?(\1?)test/ matched against "hello world test". This bug was
315        introduced in release 8.13.
317    6.  Add support for 16-bit character strings (a large amount of work involving
318        many changes and refactorings).
320    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
321        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
322        from a file.
324    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
325        rounding is not applied in this particular case).
327    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
328        if they appear, or are escaped, in patterns.
330    10. Get rid of a number of -Wunused-but-set-variable warnings.
332    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
333        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
334        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
335        also returns the mark "x". This bug applied to capturing parentheses,
336        non-capturing parentheses, and atomic parentheses. It also applied to some
337        assertions.
339    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
340        information out of configure.ac instead of relying on pcre.h.generic, which
341        is not stored in the repository.
343    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
344        -lreadline.
346    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
348    15. Applied Graycode's patch to put the top-level frame on the stack rather
349        than the heap when not using the stack for recursion. This gives a
350        performance improvement in many cases when recursion is not deep.
352    16. Experimental code added to "pcretest -C" to output the stack frame size.
355    Version 8.21 12-Dec-2011
356    ------------------------
358    1.  Updating the JIT compiler.
360    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
361        are added as well.
363    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
364        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
365        calling _pcre_jit_exec. Some extra comments are added.
367    4.  (*MARK) settings inside atomic groups that do not contain any capturing
368        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
369        was introduced by change 18 for 8.20.
371    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
372        ECMA-262 standard.
374    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
375        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
376        This bug was probably introduced by change 9 of 8.13.
378    7.  While fixing 6 above, I noticed that a number of other items were being
379        incorrectly rejected as "not fixed length". This arose partly because newer
380        opcodes had not been added to the fixed-length checking code. I have (a)
381        corrected the bug and added tests for these items, and (b) arranged for an
382        error to occur if an unknown opcode is encountered while checking for fixed
383        length instead of just assuming "not fixed length". The items that were
384        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
385        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
386        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
388    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
389        being incorrectly compiled and would have given unpredicatble results.
391    9.  A possessively repeated subpattern with minimum repeat count greater than
392        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
393        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
394        the first (A) could occur when it should not.
396    10. Add a cast and remove a redundant test from the code.
398    11. JIT should use pcre_malloc/pcre_free for allocation.
400    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
401        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
402        is anything other than /usr, -L is still shown).
404    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
406    14. Perl does not support \N without a following name in a [] class; PCRE now
407        also gives an error.
409    15. If a forward reference was repeated with an upper limit of around 2000,
410        it caused the error "internal error: overran compiling workspace". The
411        maximum number of forward references (including repeats) was limited by the
412        internal workspace, and dependent on the LINK_SIZE. The code has been
413        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
414        the default depends on LINK_SIZE. There is a new upper limit (for safety)
415        of around 200,000 forward references. While doing this, I also speeded up
416        the filling in of repeated forward references.
418    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
419        incorrectly expecting the subject to contain another "a" after the start.
421    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
422        in the match, the SKIP should be ignored. This was not happening; instead
423        the SKIP was being treated as NOMATCH. For patterns such as
424        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
425        tested.
427    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
428        now much more compatible with Perl, in particular in cases where the result
429        is a non-match for a non-anchored pattern. For example, if
430        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
431        "m", where previously it did not return a name. A side effect of this
432        change is that for partial matches, the last encountered mark name is
433        returned, as for non matches. A number of tests that were previously not
434        Perl-compatible have been moved into the Perl-compatible test files. The
435        refactoring has had the pleasing side effect of removing one argument from
436        the match() function, thus reducing its stack requirements.
438    19. If the /S+ option was used in pcretest to study a pattern using JIT,
439        subsequent uses of /S (without +) incorrectly behaved like /S+.
441    21. Retrieve executable code size support for the JIT compiler and fixing
442        some warnings.
444    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
445        not work when the shorter character appeared right at the end of the
446        subject string.
448    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
449        systems.
451    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
452        output it when the /M option is used in pcretest.
454    25. The CheckMan script was not being included in the distribution. Also, added
455        an explicit "perl" to run Perl scripts from the PrepareRelease script
456        because this is reportedly needed in Windows.
458    26. If study data was being save in a file and studying had not found a set of
459        "starts with" bytes for the pattern, the data written to the file (though
460        never used) was taken from uninitialized memory and so caused valgrind to
461        complain.
463    27. Updated RunTest.bat as provided by Sheri Pierce.
465    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
467    29. Computation of memory usage for the table of capturing group names was
468        giving an unnecessarily large value.
471    Version 8.20 21-Oct-2011
472    ------------------------
474    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
475        a POSIX class. After further experiments with Perl, which convinced me that
476        Perl has bugs and confusions, a closing square bracket is no longer allowed
477        in a POSIX name. This bug also affected patterns with classes that started
478        with full stops.
480    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
481        captured substring, but while checking the failing first alternative,
482        substring 1 is temporarily captured. If the output vector supplied to
483        pcre_exec() was not big enough for this capture, the yield of the function
484        was still zero ("insufficient space for captured substrings"). This cannot
485        be totally fixed without adding another stack variable, which seems a lot
486        of expense for a edge case. However, I have improved the situation in cases
487        such as /(a)(b)x|abc/ matched against "abc", where the return code
488        indicates that fewer than the maximum number of slots in the ovector have
489        been set.
491    3.  Related to (2) above: when there are more back references in a pattern than
492        slots in the output vector, pcre_exec() uses temporary memory during
493        matching, and copies in the captures as far as possible afterwards. It was
494        using the entire output vector, but this conflicts with the specification
495        that only 2/3 is used for passing back captured substrings. Now it uses
496        only the first 2/3, for compatibility. This is, of course, another edge
497        case.
499    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
500        main code base, and can be used by building with --enable-jit. When this is
501        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
502        runtime --no-jit option is given.
504    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
505        ovector, the return from the function was zero, implying that there were
506        other matches that did not fit. The correct "exactly full" value is now
507        returned.
509    6.  If a subpattern that was called recursively or as a subroutine contained
510        (*PRUNE) or any other control that caused it to give a non-standard return,
511        invalid errors such as "Error -26 (nested recursion at the same subject
512        position)" or even infinite loops could occur.
514    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
515        computing the minimum length on reaching *ACCEPT, and so ended up with the
516        wrong value of 1 rather than 0. Further investigation indicates that
517        computing a minimum subject length in the presence of *ACCEPT is difficult
518        (think back references, subroutine calls), and so I have changed the code
519        so that no minimum is registered for a pattern that contains *ACCEPT.
521    8.  If (*THEN) was present in the first (true) branch of a conditional group,
522        it was not handled as intended. [But see 16 below.]
524    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
525        Sheri Pierce.
527    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
528        the first byte in a match must be "a".
530    11. Change 17 for 8.13 increased the recursion depth for patterns like
531        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
532        pattern contains any instances of (*THEN). If it does not, the old
533        optimizations are restored. It would be nice to do this on a per-group
534        basis, but at the moment that is not feasible.
536    12. In some environments, the output of pcretest -C is CRLF terminated. This
537        broke RunTest's code that checks for the link size. A single white space
538        character after the value is now allowed for.
540    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
541        For "fr", it uses the Windows-specific input and output files.
543    14. If (*THEN) appeared in a group that was called recursively or as a
544        subroutine, it did not work as intended. [But see next item.]
546    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
547        pattern fragments (but not containing any | characters). If A and B are
548        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
549        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
550        D. In other words, Perl considers parentheses that do not contain any |
551        characters to be part of a surrounding alternative, whereas PCRE was
552        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
553        differently. PCRE now behaves in the same way as Perl, except in the case
554        of subroutine/recursion calls such as (?1) which have in any case always
555        been different (but PCRE had them first :-).
557    16. Related to 15 above: Perl does not treat the | in a conditional group as
558        creating alternatives. Such a group is treated in the same way as an
559        ordinary group without any | characters when processing (*THEN). PCRE has
560        been changed to match Perl's behaviour.
562    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
563        RunGrepTest script failed.
565    18. Change 22 for version 13 caused atomic groups to use more stack. This is
566        inevitable for groups that contain captures, but it can lead to a lot of
567        stack use in large patterns. The old behaviour has been restored for atomic
568        groups that do not contain any capturing parentheses.
570    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
571        suppress the check for a minimum subject length at run time. (If it was
572        given to pcre_exec() or pcre_dfa_exec() it did work.)
574    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
575        fail to work when decoding hex characters in data strings in EBCDIC
576        environments.
578    21. It appears that in at least one Mac OS environment, the isxdigit() function
579        is implemented as a macro that evaluates to its argument more than once,
580        contravening the C 90 Standard (I haven't checked a later standard). There
581        was an instance in pcretest which caused it to go wrong when processing
582        \x{...} escapes in subject strings. The has been rewritten to avoid using
583        things like p++ in the argument of isxdigit().
586    Version 8.13 16-Aug-2011
587    ------------------------
589    1.  The Unicode data tables have been updated to Unicode 6.0.0.
591    2.  Two minor typos in pcre_internal.h have been fixed.
593    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
594        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
595        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
597    4.  There were a number of related bugs in the code for matching backrefences
598        caselessly in UTF-8 mode when codes for the characters concerned were
599        different numbers of bytes. For example, U+023A and U+2C65 are an upper
600        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
601        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
602        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
603        2-byte code at the end of the subject (it thought there wasn't enough data
604        left).
606    5.  Comprehensive information about what went wrong is now returned by
607        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
608        as the output vector has at least 2 elements. The offset of the start of
609        the failing character and a reason code are placed in the vector.
611    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
612        now returned is for the first byte of the failing character, instead of the
613        last byte inspected. This is an incompatible change, but I hope it is small
614        enough not to be a problem. It makes the returned offset consistent with
615        pcre_exec() and pcre_dfa_exec().
617    7.  pcretest now gives a text phrase as well as the error number when
618        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
619        failure, the offset and reason code are output.
621    8.  When \R was used with a maximizing quantifier it failed to skip backwards
622        over a \r\n pair if the subsequent match failed. Instead, it just skipped
623        back over a single character (\n). This seems wrong (because it treated the
624        two characters as a single entity when going forwards), conflicts with the
625        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
626        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
627        has been changed.
629    9.  Some internal refactoring has changed the processing so that the handling
630        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
631        time (the PCRE_DOTALL option was changed this way some time ago: version
632        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
633        which was always a bit of a fudge. It also means that there is one less
634        argument for the match() function, which reduces its stack requirements
635        slightly. This change also fixes an incompatibility with Perl: the pattern
636        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
638    10. More internal refactoring has drastically reduced the number of recursive
639        calls to match() for possessively repeated groups such as (abc)++ when
640        using pcre_exec().
642    11. While implementing 10, a number of bugs in the handling of groups were
643        discovered and fixed:
645        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
646        (a|)*(?1) gave a compile-time internal error.
647        ((a|)+)+  did not notice that the outer group could match an empty string.
648        (^a|^)+   was not marked as anchored.
649        (.*a|.*)+ was not marked as matching at start or after a newline.
651    12. Yet more internal refactoring has removed another argument from the match()
652        function. Special calls to this function are now indicated by setting a
653        value in a variable in the "match data" data block.
655    13. Be more explicit in pcre_study() instead of relying on "default" for
656        opcodes that mean there is no starting character; this means that when new
657        ones are added and accidentally left out of pcre_study(), testing should
658        pick them up.
660    14. The -s option of pcretest has been documented for ages as being an old
661        synonym of -m (show memory usage). I have changed it to mean "force study
662        for every regex", that is, assume /S for every regex. This is similar to -i
663        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
664        using it. It makes it easier to run collections of tests with and without
665        study enabled, and thereby test pcre_study() more easily. All the standard
666        tests are now run with and without -s (but some patterns can be marked as
667        "never study" - see 20 below).
669    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
670        restoration of the capturing data to the outer values was not happening
671        correctly.
673    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
674        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
675        pattern had matched an empty string, and so incorrectly returned a no
676        match.
678    17. There was optimizing code for the last branch of non-capturing parentheses,
679        and also for the obeyed branch of a conditional subexpression, which used
680        tail recursion to cut down on stack usage. Unfortunately, now that there is
681        the possibility of (*THEN) occurring in these branches, tail recursion is
682        no longer possible because the return has to be checked for (*THEN). These
683        two optimizations have therefore been removed. [But see 8.20/11 above.]
685    18. If a pattern containing \R was studied, it was assumed that \R always
686        matched two bytes, thus causing the minimum subject length to be
687        incorrectly computed because \R can also match just one byte.
689    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
690        was incorrectly computed.
692    20. If /S is present twice on a test pattern in pcretest input, it now
693        *disables* studying, thereby overriding the use of -s on the command line
694        (see 14 above). This is necessary for one or two tests to keep the output
695        identical in both cases.
697    21. When (*ACCEPT) was used in an assertion that matched an empty string and
698        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
700    22. When an atomic group that contained a capturing parenthesis was
701        successfully matched, but the branch in which it appeared failed, the
702        capturing was not being forgotten if a higher numbered group was later
703        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
704        group 1 to "a", when in fact it should be unset. This applied to multi-
705        branched capturing and non-capturing groups, repeated or not, and also to
706        positive assertions (capturing in negative assertions does not happen
707        in PCRE) and also to nested atomic groups.
709    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
710        subject after a captured substring, to make it easier to tell which of a
711        number of identical substrings has been captured.
713    24. The way atomic groups are processed by pcre_exec() has been changed so that
714        if they are repeated, backtracking one repetition now resets captured
715        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
716        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
717        "aaa". Previously, it would have been "a". As part of this code
718        refactoring, the way recursive calls are handled has also been changed.
720    25. If an assertion condition captured any substrings, they were not passed
721        back unless some other capturing happened later. For example, if
722        (?(?=(a))a) was matched against "a", no capturing was returned.
724    26. When studying a pattern that contained subroutine calls or assertions,
725        the code for finding the minimum length of a possible match was handling
726        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
727        group 1 called group 2 while simultaneously a separate group 2 called group
728        1). A stack overflow occurred in this case. I have fixed this by limiting
729        the recursion depth to 10.
731    27. Updated RunTest.bat in the distribution to the version supplied by Tom
732        Fortmann. This supports explicit test numbers on the command line, and has
733        argument validation and error reporting.
735    28. An instance of \X with an unlimited repeat could fail if at any point the
736        first character it looked at was a mark character.
738    29. Some minor code refactoring concerning Unicode properties and scripts
739        should reduce the stack requirement of match() slightly.
741    30. Added the '=' option to pcretest to check the setting of unused capturing
742        slots at the end of the pattern, which are documented as being -1, but are
743        not included in the return count.
745    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
746        compiled something random. Now it gives a compile-time error (as does
747        Perl).
749    32. A *MARK encountered during the processing of a positive assertion is now
750        recorded and passed back (compatible with Perl).
752    33. If --only-matching or --colour was set on a pcregrep call whose pattern
753        had alternative anchored branches, the search for a second match in a line
754        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
755        matched the line "0102" twice. The same bug affected patterns that started
756        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
757        twice.
759    34. Previously, PCRE did not allow quantification of assertions. However, Perl
760        does, and because of capturing effects, quantifying parenthesized
761        assertions may at times be useful. Quantifiers are now allowed for
762        parenthesized assertions.
764    35. A minor code tidy in pcre_compile() when checking options for \R usage.
766    36. \g was being checked for fancy things in a character class, when it should
767        just be a literal "g".
769    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
770        appearance of a nested POSIX class supersedes an apparent external class.
771        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
772        unescaped square brackets may also appear as part of class names. For
773        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
774        more like Perl. (But see 8.20/1 above.)
776    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
777        was because it thought it was \N{name}, which is not supported).
779    39. Add minix to OS list not supporting the -S option in pcretest.
781    40. PCRE tries to detect cases of infinite recursion at compile time, but it
782        cannot analyze patterns in sufficient detail to catch mutual recursions
783        such as ((?1))((?2)). There is now a runtime test that gives an error if a
784        subgroup is called recursively as a subpattern for a second time at the
785        same position in the subject string. In previous releases this might have
786        been caught by the recursion limit, or it might have run out of stack.
788    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
789        happen only once. PCRE was, however incorrectly giving a compile time error
790        "recursive call could loop indefinitely" because it cannot analyze the
791        pattern in sufficient detail. The compile time test no longer happens when
792        PCRE is compiling a conditional subpattern, but actual runaway loops are
793        now caught at runtime (see 40 above).
795    42. It seems that Perl allows any characters other than a closing parenthesis
796        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
797        has been changed to be the same.
799    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
800        as not to get warnings when autogen.sh is called. Also changed
801        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
803    44. To help people who use pcregrep to scan files containing exceedingly long
804        lines, the following changes have been made:
806        (a) The default value of the buffer size parameter has been increased from
807            8K to 20K. (The actual buffer used is three times this size.)
809        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
810            PCRE is built.
812        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
813            to be set at run time.
815        (d) Numerical values in pcregrep options can be followed by K or M, for
816            example --buffer-size=50K.
818        (e) If a line being scanned overflows pcregrep's buffer, an error is now
819            given and the return code is set to 2.
821    45. Add a pointer to the latest mark to the callout data block.
823    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
824        partial match of an empty string instead of no match. This was specific to
825        the use of ".".
827    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
828        complete match instead of a partial match. This bug was dependent on both
829        the PCRE_UTF8 and PCRE_DOTALL options being set.
831    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
832        starting byte set, because \b was not being ignored.
835    Version 8.12 15-Jan-2011
836    ------------------------
838    1.  Fixed some typos in the markup of the man pages, and wrote a script that
839        checks for such things as part of the documentation building process.
841    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
842        --match-limit and --recursion-limit options (added for 8.11). In
843        particular, this made one of the standard tests fail. (The integer value
844        went into the wrong half of a long int.)
846    3.  If the --colour option was given to pcregrep with -v (invert match), it
847        did strange things, either producing crazy output, or crashing. It should,
848        of course, ignore a request for colour when reporting lines that do not
849        match.
851    4.  Another pcregrep bug caused similar problems if --colour was specified with
852        -M (multiline) and the pattern match finished with a line ending.
854    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
855        matched in multiline mode, the following line was shown as part of the
856        match. This seems wrong, so I have changed it.
858    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
859        the check for further matches in the same line (so they could be coloured)
860        to overrun the end of the current line. If another match was found, it was
861        incorrectly shown (and then shown again when found in the next line).
863    7.  If pcregrep was compiled under Windows, there was a reference to the
864        function pcregrep_exit() before it was defined. I am assuming this was
865        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
866        reported by a user. I've moved the definition above the reference.
869    Version 8.11 10-Dec-2010
870    ------------------------
872    1.  (*THEN) was not working properly if there were untried alternatives prior
873        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
874        backtracked to try for "b" instead of moving to the next alternative branch
875        at the same level (in this case, to look for "c"). The Perl documentation
876        is clear that when (*THEN) is backtracked onto, it goes to the "next
877        alternative in the innermost enclosing group".
879    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
880        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
881        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
882        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
883        (*THEN).
885    3.  If \s appeared in a character class, it removed the VT character from
886        the class, even if it had been included by some previous item, for example
887        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
888        of \s, but is part of the POSIX "space" class.)
890    4.  A partial match never returns an empty string (because you can always
891        match an empty string at the end of the subject); however the checking for
892        an empty string was starting at the "start of match" point. This has been
893        changed to the "earliest inspected character" point, because the returned
894        data for a partial match starts at this character. This means that, for
895        example, /(?<=abc)def/ gives a partial match for the subject "abc"
896        (previously it gave "no match").
898    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
899        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
900        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
901        has an implication that the given string is incomplete (because a partial
902        match is preferred over a full match). For this reason, these items now
903        give a partial match in this situation. [Aside: previously, the one case
904        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
905        match rather than a full match, which was wrong by the old rules, but is
906        now correct.]
908    6.  There was a bug in the handling of #-introduced comments, recognized when
909        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
910        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
911        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
912        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
913        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
914        places in pcre_compile().
916    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
917        comments when looking ahead for named forward references to subpatterns,
918        the only newline sequence it recognized was NL. It now handles newlines
919        according to the set newline convention.
921    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
922        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
923        cater for a lack of strerror(). These oversights have been fixed.
925    9.  Added --match-limit and --recursion-limit to pcregrep.
927    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
929    11. When the -o option was used, pcregrep was setting a return code of 1, even
930        when matches were found, and --line-buffered was not being honoured.
932    12. Added an optional parentheses number to the -o and --only-matching options
933        of pcregrep.
935    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
936        can match an empty string. The code to do it in pcretest and pcredemo
937        needed fixing:
939        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
940            only one byte after an empty string match just before CRLF (this case
941            just got forgotten; "any" and "anycrlf" were OK).
943        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
944            mode when an empty string match preceded an ASCII character followed by
945            a non-ASCII character. (The code for advancing by one character rather
946            than one byte was nonsense.)
948        (c) The pcredemo.c sample program did not have any code at all to handle
949            the cases when CRLF is a valid newline sequence.
951    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
952        as a starting offset was within the subject string. There is now a new
953        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
954        negative or greater than the length of the string. In order to test this,
955        pcretest is extended to allow the setting of negative starting offsets.
957    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
958        starting offset points to the beginning of a UTF-8 character was
959        unnecessarily clumsy. I tidied it up.
961    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
962        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
964    17. Nobody had reported that the --include_dir option, which was added in
965        release 7.7 should have been called --include-dir (hyphen, not underscore)
966        for compatibility with GNU grep. I have changed it to --include-dir, but
967        left --include_dir as an undocumented synonym, and the same for
968        --exclude-dir, though that is not available in GNU grep, at least as of
969        release 2.5.4.
971    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
972        characters from a string of bytes) have been redefined so as not to use
973        loops, in order to improve performance in some environments. At the same
974        time, I abstracted some of the common code into auxiliary macros to save
975        repetition (this should not affect the compiled code).
977    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
978        compile-time error is now given if \c is not followed by an ASCII
979        character, that is, a byte less than 128. (In EBCDIC mode, the code is
980        different, and any byte value is allowed.)
982    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
983        START_OPTIMIZE option, which is now allowed at compile time - but just
984        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
985        to pcregrep and other applications that have no direct access to PCRE
986        options. The new /Y option in pcretest sets this option when calling
987        pcre_compile().
989    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
990        back references. Groups containing recursive back references were forced to
991        be atomic by that change, but in the case of named groups, the amount of
992        memory required was incorrectly computed, leading to "Failed: internal
993        error: code overflow". This has been fixed.
995    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
996        pcretest.c, to avoid build problems in some Borland environments.
999    Version 8.10 25-Jun-2010
1000    ------------------------
1002    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1003        THEN.
1005    2.  (*ACCEPT) was not working when inside an atomic group.
1007    3.  Inside a character class, \B is treated as a literal by default, but
1008        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1009        causes the error). The code is unchanged, but I tidied the documentation.
1011    4.  Inside a character class, PCRE always treated \R and \X as literals,
1012        whereas Perl faults them if its -w option is set. I have changed PCRE so
1013        that it faults them when PCRE_EXTRA is set.
1015    5.  Added support for \N, which always matches any character other than
1016        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1018    6.  When compiling pcregrep with newer versions of gcc which may have
1019        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1020        declared with attribute warn_unused_result" were given. Just casting the
1021        result to (void) does not stop the warnings; a more elaborate fudge is
1022        needed. I've used a macro to implement this.
1024    7.  Minor change to pcretest.c to avoid a compiler warning.
1026    8.  Added four artifical Unicode properties to help with an option to make
1027        \s etc use properties (see next item). The new properties are: Xan
1028        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1030    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1031        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1032        this option. Modified pcretest to add /W to test this facility. Added
1033        REG_UCP to make it available via the POSIX interface.
1035    10. Added --line-buffered to pcregrep.
1037    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1038        studied, and the match started with a letter with a code point greater than
1039        127 whose first byte was different to the first byte of the other case of
1040        the letter, the other case of this starting letter was not recognized
1041        (#976).
1043    12. If a pattern that was studied started with a repeated Unicode property
1044        test, for example, \p{Nd}+, there was the theoretical possibility of
1045        setting up an incorrect bitmap of starting bytes, but fortunately it could
1046        not have actually happened in practice until change 8 above was made (it
1047        added property types that matched character-matching opcodes).
1049    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1050        possible starting bytes for non-anchored patterns.
1052    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1053        \R, and also a number of cases that involve Unicode properties, both
1054        explicit and implicit when PCRE_UCP is set.
1056    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1057        input, it could crash or give wrong results if characters with values
1058        greater than 0xc0 were present in the subject string. (Detail: it assumed
1059        UTF-8 input when processing these items.)
1061    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1062        size_t is 64-bit (#991).
1064    17. Added a check for running out of memory when PCRE is compiled with
1065        --disable-stack-for-recursion (#990).
1067    18. If the last data line in a file for pcretest does not have a newline on
1068        the end, a newline was missing in the output.
1070    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1071        less than 128) in its various bitmaps. However, there is a facility for
1072        generating tables according to the current locale when PCRE is compiled. It
1073        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1074        characters, are recognized by isspace() and therefore were getting set in
1075        these tables, and indeed these tables seem to approximate to ISO 8859. This
1076        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1077        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1078        which of course cannot start UTF-8 characters. I have changed the code so
1079        that only real ASCII characters (less than 128) and the correct starting
1080        bytes for UTF-8 encodings are set for characters greater than 127 when in
1081        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1082        altogether.)
1084    20. Added the /T option to pcretest so as to be able to run tests with non-
1085        standard character tables, thus making it possible to include the tests
1086        used for 19 above in the standard set of tests.
1088    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1089        reference to a subpattern the other side of a comment that contains an
1090        opening parenthesis caused either an internal compiling error, or a
1091        reference to the wrong subpattern.
1094    Version 8.02 19-Mar-2010
1095    ------------------------
1097    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1099    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1100        configured.
1102    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1103        original author of that file, following a query about its status.
1105    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1106        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1108    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1109        quantifier applied to a forward-referencing subroutine call, could compile
1110        incorrect code or give the error "internal error: previously-checked
1111        referenced subpattern not found".
1113    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1114        variables to point to external functions. For these systems, therefore,
1115        pcre_malloc etc. are now initialized to local functions that call the
1116        relevant global functions.
1118    7.  There were two entries missing in the vectors called coptable and poptable
1119        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1120        I've fixed the data, and added a kludgy way of testing at compile time that
1121        the lengths are correct (equal to the number of opcodes).
1123    8.  Following on from 7, I added a similar kludge to check the length of the
1124        eint vector in pcreposix.c.
1126    9.  Error texts for pcre_compile() are held as one long string to avoid too
1127        much relocation at load time. To find a text, the string is searched,
1128        counting zeros. There was no check for running off the end of the string,
1129        which could happen if a new error number was added without updating the
1130        string.
1132    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1134    11. \K was not working if it appeared in an atomic group or in a group that
1135        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1136        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1137        the assertion is positive, but not if it is negative.
1139    12. Change 11 fortuitously reduced the size of the stack frame used in the
1140        "match()" function of pcre_exec.c by one pointer. Forthcoming
1141        implementation of support for (*MARK) will need an extra pointer on the
1142        stack; I have reserved it now, so that the stack frame size does not
1143        decrease.
1145    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1146        item in branch that calls a recursion is a subroutine call - as in the
1147        second branch in the above example - was incorrectly given the compile-
1148        time error "recursive call could loop indefinitely" because pcre_compile()
1149        was not correctly checking the subroutine for matching a non-empty string.
1151    14. The checks for overrunning compiling workspace could trigger after an
1152        overrun had occurred. This is a "should never occur" error, but it can be
1153        triggered by pathological patterns such as hundreds of nested parentheses.
1154        The checks now trigger 100 bytes before the end of the workspace.
1156    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1159    Version 8.01 19-Jan-2010
1160    ------------------------
1162    1.  If a pattern contained a conditional subpattern with only one branch (in
1163        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1164        computed the wrong minimum data length (which is of course zero for such
1165        subpatterns). This could cause incorrect "no match" results.
1167    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1168        the pattern is reset in the first branch, pcre_compile() failed with
1169        "internal error: code overflow at offset...". This happened only when
1170        the reset was to the original external option setting. (An optimization
1171        abstracts leading options settings into an external setting, which was the
1172        cause of this.)
1174    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1175        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1176        assertion pattern did not match (meaning that the assertion was true), it
1177        was incorrectly treated as false if the SKIP had been reached during the
1178        matching. This also applied to assertions used as conditions.
1180    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1181        assertion subpattern, including such a pattern used as a condition,
1182        unpredictable results occurred, instead of the error return
1185    5.  The C++ GlobalReplace function was not working like Perl for the special
1186        situation when an empty string is matched. It now does the fancy magic
1187        stuff that is necessary.
1189    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1190        removed. (These were left over from very, very early versions of PCRE.)
1192    7.  Some cosmetic changes to the code to make life easier when compiling it
1193        as part of something else:
1195        (a) Change DEBUG to PCRE_DEBUG.
1197        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1198            called "current" as "current_branch", to prevent a collision with the
1199            Linux macro when compiled as a kernel module.
1201        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1202            prevent a collision with the Linux macro when compiled as a kernel
1203            module.
1205    8.  In pcre_compile() there are some checks for integer overflows that used to
1206        cast potentially large values to (double). This has been changed to that
1207        when building, a check for int64_t is made, and if it is found, it is used
1208        instead, thus avoiding the use of floating point arithmetic. (There is no
1209        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1210        double.
1212    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1213        2005 (difference between two addresses compared to an unsigned value).
1215    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1216        custom one, because of the following reported problem in Windows:
1218          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1219              under Win32.
1220          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1221              therefore missing the function definition.
1222          - The compiler thus generates a "C" signature for the test function.
1223          - The linker fails to find the "C" function.
1224          - PCRE fails to configure if asked to do so against libbz2.
1226    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1227        messages were output:
1229          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1230          rerunning libtoolize, to keep the correct libtool macros in-tree.
1231          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1233        I have done both of these things.
1235    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1236        most of the time, it *can* run out if it is given a pattern that contains a
1237        runaway infinite recursion. I updated the discussion in the pcrestack man
1238        page.
1240    13. Now that we have gone to the x.xx style of version numbers, the minor
1241        version may start with zero. Using 08 or 09 is a bad idea because users
1242        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1243        interpreted as invalid octal numbers. I've updated the previous comment in
1244        configure.ac, and also added a check that gives an error if 08 or 09 are
1245        used.
1247    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1248        causing partial matching to fail when the end of the subject matched \W
1249        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1251    15. There were some discrepancies between the declarations in pcre_internal.h
1252        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1253        their definitions. The declarations used "const uschar *" and the
1254        definitions used USPTR. Even though USPTR is normally defined as "const
1255        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1256        reported that: "This difference in casting confuses some C++ compilers, for
1257        example, SunCC recognizes above declarations as different functions and
1258        generates broken code for hbpcre." I have changed the declarations to use
1259        USPTR.
1261    16. GNU libtool is named differently on some systems. The autogen.sh script now
1262        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1263        (FreeBSD).
1265    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1266        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1267        comment: "Figure out how to create a longlong from a string: strtoll and
1268        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1269        instance, but it only takes 2 args instead of 3!"
1271    18. A subtle bug concerned with back references has been fixed by a change of
1272        specification, with a corresponding code fix. A pattern such as
1273        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1274        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1275        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1276        same bug. Such groups have to be quantified to be useful, or contained
1277        inside another quantified group. (If there's no repetition, the reference
1278        can never match.) The problem arises because, having left the group and
1279        moved on to the rest of the pattern, a later failure that backtracks into
1280        the group uses the captured value from the final iteration of the group
1281        rather than the correct earlier one. I have fixed this in PCRE by forcing
1282        any group that contains a reference to itself to be an atomic group; that
1283        is, there cannot be any backtracking into it once it has completed. This is
1284        similar to recursive and subroutine calls.
1287    Version 8.00 19-Oct-09
1288    ----------------------
1290    1.  The table for translating pcre_compile() error codes into POSIX error codes
1291        was out-of-date, and there was no check on the pcre_compile() error code
1292        being within the table. This could lead to an OK return being given in
1293        error.
1295    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1296        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1297        in a Windows environment.
1299    3.  The pcregrep --count option prints the count for each file even when it is
1300        zero, as does GNU grep. However, pcregrep was also printing all files when
1301        --files-with-matches was added. Now, when both options are given, it prints
1302        counts only for those files that have at least one match. (GNU grep just
1303        prints the file name in this circumstance, but including the count seems
1304        more useful - otherwise, why use --count?) Also ensured that the
1305        combination -clh just lists non-zero counts, with no names.
1307    4.  The long form of the pcregrep -F option was incorrectly implemented as
1308        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1309        but it seems right to fix it, and I didn't think it was worth preserving
1310        the old behaviour.
1312    5.  The command line items --regex=pattern and --regexp=pattern were not
1313        recognized by pcregrep, which required --regex pattern or --regexp pattern
1314        (with a space rather than an '='). The man page documented the '=' forms,
1315        which are compatible with GNU grep; these now work.
1317    6.  No libpcreposix.pc file was created for pkg-config; there was just
1318        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1320    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1321        when UCP support is not needed, by modifying the Python script that
1322        generates it from Unicode data files. This should not matter if the module
1323        is correctly used as a library, but I received one complaint about 50K of
1324        unwanted data. My guess is that the person linked everything into his
1325        program rather than using a library. Anyway, it does no harm.
1327    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1328        was a minimum greater than 1 for a wide character in a possessive
1329        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1330        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1331        character. Chaos in the form of incorrect output or a compiling loop could
1332        result.
1334    9.  The restrictions on what a pattern can contain when partial matching is
1335        requested for pcre_exec() have been removed. All patterns can now be
1336        partially matched by this function. In addition, if there are at least two
1337        slots in the offset vector, the offset of the earliest inspected character
1338        for the match and the offset of the end of the subject are set in them when
1339        PCRE_ERROR_PARTIAL is returned.
1341    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1342        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1343        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1344        and may be more useful for multi-segment matching.
1346    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1347        used to be given if ever the end of the subject was reached; now it is
1348        given only if matching could not proceed because another character was
1349        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1350        string "Z", which now yields "no match" instead of "partial match". In the
1351        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1352        final character ended with (*FAIL).
1354    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1355        if the pattern had a "must contain" character that was already found in the
1356        earlier partial match, unless partial matching was again requested. For
1357        example, with the pattern /dog.(body)?/, the "must contain" character is
1358        "g". If the first part-match was for the string "dog", restarting with
1359        "sbody" failed. This bug has been fixed.
1361    13. The string returned by pcre_dfa_exec() after a partial match has been
1362        changed so that it starts at the first inspected character rather than the
1363        first character of the match. This makes a difference only if the pattern
1364        starts with a lookbehind assertion or \b or \B (\K is not supported by
1365        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1366        matching functions compatible, and I think it's the right thing to do.
1368    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1369        so that the demonstration program is easily available in environments where
1370        PCRE has not been installed from source.
1372    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1373        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1374        library.
1376    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1377        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1378        is not the first non-POSIX option to be added. Clearly some people find
1379        these options useful.
1381    17. If a caller to the POSIX matching function regexec() passes a non-zero
1382        value for nmatch with a NULL value for pmatch, the value of
1383        nmatch is forced to zero.
1385    18. RunGrepTest did not have a test for the availability of the -u option of
1386        the diff command, as RunTest does. It now checks in the same way as
1387        RunTest, and also checks for the -b option.
1389    19. If an odd number of negated classes containing just a single character
1390        interposed, within parentheses, between a forward reference to a named
1391        subpattern and the definition of the subpattern, compilation crashed with
1392        an internal error, complaining that it could not find the referenced
1393        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1394        [The bug was that it was starting one character too far in when skipping
1395        over the character class, thus treating the ] as data rather than
1396        terminating the class. This meant it could skip too much.]
1398    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1399        /g option in pcretest when the pattern contains \K, which makes it possible
1400        to have an empty string match not at the start, even when the pattern is
1401        anchored. Updated pcretest and pcredemo to use this option.
1403    21. If the maximum number of capturing subpatterns in a recursion was greater
1404        than the maximum at the outer level, the higher number was returned, but
1405        with unset values at the outer level. The correct (outer level) value is
1406        now given.
1408    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1409        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1410        make it do so. The string so far is captured, making this feature
1411        compatible with Perl.
1413    23. The tests have been re-organized, adding tests 11 and 12, to make it
1414        possible to check the Perl 5.10 features against Perl 5.10.
1416    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1417        pattern matches a fixed length string. PCRE did not allow this; now it
1418        does. Neither allows recursion.
1420    25. I finally figured out how to implement a request to provide the minimum
1421        length of subject string that was needed in order to match a given pattern.
1422        (It was back references and recursion that I had previously got hung up
1423        on.) This code has now been added to pcre_study(); it finds a lower bound
1424        to the length of subject needed. It is not necessarily the greatest lower
1425        bound, but using it to avoid searching strings that are too short does give
1426        some useful speed-ups. The value is available to calling programs via
1427        pcre_fullinfo().
1429    26. While implementing 25, I discovered to my embarrassment that pcretest had
1430        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1431        study optimizations had never been tested with that matching function.
1432        Oops. What is worse, even when it was passed study data, there was a bug in
1433        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1434        were also very few tests of studied patterns with pcre_dfa_exec().
1436    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1437        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1438        on the other side of the coin, they are no longer allowed to have different
1439        names, because these cannot be distinguished in PCRE, and this has caused
1440        confusion. (This is a difference from Perl.)
1442    28. When duplicate subpattern names are present (necessarily with different
1443        numbers, as required by 27 above), and a test is made by name in a
1444        conditional pattern, either for a subpattern having been matched, or for
1445        recursion in such a pattern, all the associated numbered subpatterns are
1446        tested, and the overall condition is true if the condition is true for any
1447        one of them. This is the way Perl works, and is also more like the way
1448        testing by number works.
1451    Version 7.9 11-Apr-09
1452    ---------------------
1454    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1455        (pcretest), all targets were linked against these libraries. This included
1456        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1457        libraries. This caused unwanted dependencies to be created. This problem
1458        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1459        pcretest is linked with readline.
1461    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1462        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1463        moved outside it again, because FALSE and TRUE are already defined in AIX,
1464        but BOOL is not.
1466    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1467        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1469    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1470        hyphens) following file names and line numbers when outputting matching
1471        lines. This is not true; no spaces are inserted. I have also clarified the
1472        wording for the --colour (or --color) option.
1474    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1475        was not coloured; this is different to GNU grep, so I have changed it to be
1476        the same.
1478    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1479        each matching line was coloured. Now it goes on to look for further matches
1480        of any of the test patterns, which is the same behaviour as GNU grep.
1482    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1483        doesn't make sense to accept an empty string match in pcregrep, so I have
1484        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1485        seems to be how GNU grep behaves.
1487    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1488        start or after a newline", because the conditional assertion was not being
1489        correctly handled. The rule now is that both the assertion and what follows
1490        in the first alternative must satisfy the test.
1492    9.  If auto-callout was enabled in a pattern with a conditional group whose
1493        condition was an assertion, PCRE could crash during matching, both with
1494        pcre_exec() and pcre_dfa_exec().
1496    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1497        used for matching.
1499    11. Unicode property support in character classes was not working for
1500        characters (bytes) greater than 127 when not in UTF-8 mode.
1502    12. Added the -M command line option to pcretest.
1504    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1506    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1508    16. Added comments and documentation about mis-use of no_arg in the C++
1509        wrapper.
1511    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1512        from Martin Jerabek that uses macro names for all relevant character and
1513        string constants.
1515    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1516        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1517        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1518        these, but not everybody uses configure.
1520    19. A conditional group that had only one branch was not being correctly
1521        recognized as an item that could match an empty string. This meant that an
1522        enclosing group might also not be so recognized, causing infinite looping
1523        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1524        with the subject "ab", where knowledge that the repeated group can match
1525        nothing is needed in order to break the loop.
1527    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1528        exec(), but without supplying a callout function, matching went wrong.
1530    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1531        leak if the size of the offset vector was greater than 30. When the vector
1532        is smaller, the saved offsets during recursion go onto a local stack
1533        vector, but for larger vectors malloc() is used. It was failing to free
1534        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1535        error, in fact).
1537    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1538        heapframe that is used only when UTF-8 support is enabled. This caused no
1539        problem, but was untidy.
1541    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1542        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1543        included within another project.
1545    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1546        slightly modified by me:
1548          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1549              not building pcregrep.
1551          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1552              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1554    25. Forward references, both numeric and by name, in patterns that made use of
1555        duplicate group numbers, could behave incorrectly or give incorrect errors,
1556        because when scanning forward to find the reference group, PCRE was not
1557        taking into account the duplicate group numbers. A pattern such as
1558        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1560    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1561        the feature of a custom pointer more persuasive (as requested by a user).
1563    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1564        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1565        pre-defined.
1567    28. Added support for (*UTF8) at the start of a pattern.
1569    29. Arrange for flags added by the "release type" setting in CMake to be shown
1570        in the configuration summary.
1573    Version 7.8 05-Sep-08
1574    ---------------------
1576    1.  Replaced UCP searching code with optimized version as implemented for Ad
1577        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1578        stage table and inline lookup instead of a function, giving speed ups of 2
1579        to 5 times on some simple patterns that I tested. Permission was given to
1580        distribute the MultiStage2.py script that generates the tables (it's not in
1581        the tarball, but is in the Subversion repository).
1583    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1584        scripts.
1586    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1587        a group with a zero qualifier. The result of the study could be incorrect,
1588        or the function might crash, depending on the pattern.
1590    4.  Caseless matching was not working for non-ASCII characters in back
1591        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1592        It now works when Unicode Property Support is available.
1594    5.  In pcretest, an escape such as \x{de} in the data was always generating
1595        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1596        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1597        truncation.
1599    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1601    7.  Added two (int) casts to pcregrep when printing the difference of two
1602        pointers, in case they are 64-bit values.
1604    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1605        test 2 if it fails.
1607    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1608        and a #define of that name to empty if it is not externally set. This is to
1609        allow users of MSVC to set it if necessary.
1611    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1612        the convenience functions in the pcre_get.c source file.
1614    11. An option change at the start of a pattern that had top-level alternatives
1615        could cause overwriting and/or a crash. This command provoked a crash in
1616        some environments:
1618          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1620        This potential security problem was recorded as CVE-2008-2371.
1622    12. For a pattern where the match had to start at the beginning or immediately
1623        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1624        pcre_dfa_exec() could read past the end of the passed subject if there was
1625        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1626        pcretest so that it places the subject at the end of its malloc-ed buffer.
1628    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1629        exec() might read past the end of the data buffer in UTF-8 mode.
1631    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1632        the data contained the byte 0x85 as part of a UTF-8 character within its
1633        first line. This applied both to normal and DFA matching.
1635    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1636        /^[^d]*?$/8 failed to match "abc".
1638    16. Added a missing copyright notice to pcrecpp_internal.h.
1640    17. Make it more clear in the documentation that values returned from
1641        pcre_exec() in ovector are byte offsets, not character counts.
1643    18. Tidied a few places to stop certain compilers from issuing warnings.
1645    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1646        supplied by Stefan Weber. I made a further small update for 7.8 because
1647        there is a change of source arrangements: the pcre_searchfuncs.c module is
1648        replaced by pcre_ucd.c.
1651    Version 7.7 07-May-08
1652    ---------------------
1654    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1655        a string to a long long, pretend we don't even have a long long." This is
1656        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1658    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1659        pre-7.6 versions, which defined a global no_arg variable instead of putting
1660        it in the RE class. (See also #8 below.)
1662    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1663        Lopes.
1665    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1667        (1) The include/exclude patterns were being applied to the whole pathnames
1668            of files, instead of just to the final components.
1670        (2) If there was more than one level of directory, the subdirectories were
1671            skipped unless they satisfied the include/exclude conditions. This is
1672            inconsistent with GNU grep (and could even be seen as contrary to the
1673            pcregrep specification - which I improved to make it absolutely clear).
1674            The action now is always to scan all levels of directory, and just
1675            apply the include/exclude patterns to regular files.
1677    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1678        --exclude_dir in the tests to avoid scanning .svn directories.
1680    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1681        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1682        doesn't support NULs in patterns.
1684    7.  Added some missing "const"s to declarations of static tables in
1685        pcre_compile.c and pcre_dfa_exec.c.
1687    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1688        caused by fix #2  above. (Subsequently also a second patch to fix the
1689        first patch. And a third patch - this was a messy problem.)
1691    9.  Applied Craig's patch to remove the use of push_back().
1693    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1694        matching function regexec().
1696    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1697        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1698        references. PCRE supports relative numbers with this syntax (I don't think
1699        Oniguruma does).
1701    12. Previously, a group with a zero repeat such as (...){0} was completely
1702        omitted from the compiled regex. However, this means that if the group
1703        was called as a subroutine from elsewhere in the pattern, things went wrong
1704        (an internal error was given). Such groups are now left in the compiled
1705        pattern, with a new opcode that causes them to be skipped at execution
1706        time.
1708    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1709        to the way PCRE behaves:
1711        (a) A lone ] character is dis-allowed (Perl treats it as data).
1713        (b) A back reference to an unmatched subpattern matches an empty string
1714            (Perl fails the current match path).
1716        (c) A data ] in a character class must be notated as \] because if the
1717            first data character in a class is ], it defines an empty class. (In
1718            Perl it is not possible to have an empty class.) The empty class []
1719            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1720            The negative empty class [^] matches any one character, independently
1721            of the DOTALL setting.
1723    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1724        non-existent subpattern following a character class starting with ']' and
1725        containing () gave an internal compiling error instead of "reference to
1726        non-existent subpattern". Fortunately, when the pattern did exist, the
1727        compiled code was correct. (When scanning forwards to check for the
1728        existencd of the subpattern, it was treating the data ']' as terminating
1729        the class, so got the count wrong. When actually compiling, the reference
1730        was subsequently set up correctly.)
1732    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1733        it was being rejected as not supported by pcre_dfa_exec(), even though
1734        other assertions are supported. I have made pcre_dfa_exec() support
1735        (*FAIL).
1737    16. The implementation of 13c above involved the invention of a new opcode,
1738        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1739        cannot be changed at match time, I realized I could make a small
1740        improvement to matching performance by compiling OP_ALLANY instead of
1741        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1742        on the OP_ANY path.
1744    17. Compiling pcretest on Windows with readline support failed without the
1745        following two fixes: (1) Make the unistd.h include conditional on
1746        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1748    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1749        ncurses library to be included for pcretest when ReadLine support is
1750        requested, but also to allow for it to be overridden. This patch came from
1751        Daniel Bergström.
1753    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1754        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1755        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1756        spotting this.
1759    Version 7.6 28-Jan-08
1760    ---------------------
1762    1.  A character class containing a very large number of characters with
1763        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1764        overflow.
1766    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1767        HAVE_LONG_LONG is not defined.
1769    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1770        bring them up to date and include new features. This patch includes:
1772        - Fixed PH's badly added libz and libbz2 support.
1773        - Fixed a problem with static linking.
1774        - Added pcredemo. [But later removed - see 7 below.]
1775        - Fixed dftables problem and added an option.
1776        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1777            HAVE_LONG_LONG.
1778        - Added readline support for pcretest.
1779        - Added an listing of the option settings after cmake has run.
1781    4.  A user submitted a patch to Makefile that makes it easy to create
1782        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1783        Makefile.am that cause it to include this special target, without
1784        affecting anything else. Note that the same mingw target plus all
1785        the other distribution libraries and programs are now supported
1786        when configuring with CMake (see 6 below) instead of with
1787        Configure/Make.
1789    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1790        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1791        exported in the Windows port". It has not yet been confirmed that the patch
1792        solves the problem, but it does no harm.
1794    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1795        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1796        with CMake, and also correct the comment about stack recursion.
1798    7.  Remove the automatic building of pcredemo from the ./configure system and
1799        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1800        of a program that users should build themselves after PCRE is installed, so
1801        building it automatically is not really right. What is more, it gave
1802        trouble in some build environments.
1804    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1807    Version 7.5 10-Jan-08
1808    ---------------------
1810    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1811        values in parens when parsing an RE using the C++ wrapper."
1813    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1814        Characters greater than 255 were excluded from the class instead of being
1815        included.
1817    3.  The same bug as (2) above applied to negated POSIX classes such as
1818        [:^space:].
1820    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1821        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1822        I have changed it.
1824    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1825        first named subpattern) and a construct such as (?&a) would reference the
1826        first named subpattern whose name started with "a" (in other words, the
1827        length check was missing). Both these problems are fixed. "Subpattern name
1828        expected" is now given for (?&) (a zero-length name), and this patch also
1829        makes it give the same error for \k'' (previously it complained that that
1830        was a reference to a non-existent subpattern).
1832    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1833        this is right because (?- can be followed by option settings as well as by
1834        digits. I have, however, made the messages clearer.
1836    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1837        than the number used in the conditional) now cause a compile-time error.
1838        This is actually not compatible with Perl, which accepts such patterns, but
1839        treats the conditional as always being FALSE (as PCRE used to), but it
1840        seems to me that giving a diagnostic is better.
1842    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1843        and messages.
1845    9.  Fix two occurrences of "backslash" in comments that should have been
1846        "backspace".
1848    10. Remove two redundant lines of code that can never be obeyed (their function
1849        was moved elsewhere).
1851    11. The program that makes PCRE's Unicode character property table had a bug
1852        which caused it to generate incorrect table entries for sequences of
1853        characters that have the same character type, but are in different scripts.
1854        It amalgamated them into a single range, with the script of the first of
1855        them. In other words, some characters were in the wrong script. There were
1856        thirteen such cases, affecting characters in the following ranges:
1858          U+002b0 - U+002c1
1859          U+0060c - U+0060d
1860          U+0061e - U+00612
1861          U+0064b - U+0065e
1862          U+0074d - U+0076d
1863          U+01800 - U+01805
1864          U+01d00 - U+01d77
1865          U+01d9b - U+01dbf
1866          U+0200b - U+0200f
1867          U+030fc - U+030fe
1868          U+03260 - U+0327f
1869          U+0fb46 - U+0fbb1
1870          U+10450 - U+1049d
1872    12. The -o option (show only the matching part of a line) for pcregrep was not
1873        compatible with GNU grep in that, if there was more than one match in a
1874        line, it showed only the first of them. It now behaves in the same way as
1875        GNU grep.
1877    13. If the -o and -v options were combined for pcregrep, it printed a blank
1878        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1879        does the same. The return code can be used to tell if there were any
1880        non-matching lines.
1882    14. Added --file-offsets and --line-offsets to pcregrep.
1884    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1885        infinitely looping recursion. The bug was that positive lookaheads were not
1886        being skipped when checking for a possible empty match (negative lookaheads
1887        and both kinds of lookbehind were skipped).
1889    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1890        inclusion of <windows.h> to before rather than after the definition of
1891        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1893    17. Specifying a possessive quantifier with a specific limit for a Unicode
1894        character property caused pcre_compile() to compile bad code, which led at
1895        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1896        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1897        caused the error; without that there was no problem.
1899    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1901    19. Added --enable-pcretest-libreadline.
1903    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1904        RE::GlobalReplace(). As a result, the number of replacements returned was
1905        double what it should be. I removed one of the increments, but Craig sent a
1906        later patch that removed the other one (the right fix) and added unit tests
1907        that check the return values (which was not done before).
1909    21. Several CMake things:
1911        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1912            the names libpcre and libpcreposix, not just pcre and pcreposix.
1914        (2) The above change means that pcretest and pcregrep are now correctly
1915            linked with the newly-built libraries, not previously installed ones.
1919    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1920        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1921        UTF-8 newline character). The key issue is that the pattern starts .*;
1922        this means that the match must be either at the beginning, or after a
1923        newline. The bug was in the code for advancing after a failed match and
1924        checking that the new position followed a newline. It was not taking
1925        account of UTF-8 characters correctly.
1927    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1928        character classes. PCRE was not treating the sequence [:...:] as a
1929        character class unless the ... were all letters. Perl, however, seems to
1930        allow any characters between [: and :], though of course it rejects as
1931        unknown any "names" that contain non-letters, because all the known class
1932        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1933        for example, whereas PCRE did not - it did not recognize a POSIX character
1934        class. This seemed a bit dangerous, so the code has been changed to be
1935        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1936        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1937        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1938        Perl does, and where it didn't before.
1940    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1941        Windows environments %n is disabled by default.
1944    Version 7.4 21-Sep-07
1945    ---------------------
1947    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1948        means that a class such as [\s] counted as "explicit reference to CR or
1949        LF". That isn't really right - the whole point of the change was to try to
1950        help when there was an actual mention of one of the two characters. So now
1951        the change happens only if \r or \n (or a literal CR or LF) character is
1952        encountered.
1954    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1955        of both had grown to the point where there were only 3 bits left.
1956        Fortunately, there was spare space in the data structure, and so I have
1957        moved the internal flags into a new 16-bit field to free up more option
1958        bits.
1960    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1961        but did not set the internal JCHANGED flag - either of these is enough to
1962        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1963        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1964        start sets both bits.
1966    4.  Added options (at build time, compile time, exec time) to change \R from
1967        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1969    5.  doc/pcresyntax.html was missing from the distribution.
1971    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1972        compatibility, even though it is no longer used.
1974    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1975        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1976        windows.h file is present (where different names are used). [This was
1977        reversed later after testing - see 16 below.]
1979    8.  Changed all #include <config.h> to #include "config.h". There were also
1980        some further <pcre.h> cases that I changed to "pcre.h".
1982    9.  When pcregrep was used with the --colour option, it missed the line ending
1983        sequence off the lines that it output.
1985    10. It was pointed out to me that arrays of string pointers cause lots of
1986        relocations when a shared library is dynamically loaded. A technique of
1987        using a single long string with a table of offsets can drastically reduce
1988        these. I have refactored PCRE in four places to do this. The result is
1989        dramatic:
1991          Originally:                          290
1992          After changing UCP table:            187
1993          After changing error message table:   43
1994          After changing table of "verbs"       36
1995          After changing table of Posix names   22
1997        Thanks to the folks working on Gregex for glib for this insight.
1999    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2000        unicode-properties was also set.
2002    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2004    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2005        checked only for CRLF.
2007    14. Added casts to pcretest.c to avoid compiler warnings.
2009    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2011    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2012        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2013        entirely. This removes changes made in 7 above.
2015    17. The CMake files have been updated, and there is now more information about
2016        building with CMake in the NON-UNIX-USE document.
2019    Version 7.3 28-Aug-07
2020    ---------------------
2022     1. In the rejigging of the build system that eventually resulted in 7.1, the
2023        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2024        brackets there is not right, since it causes compilers to look for an
2025        installed pcre.h, not the version that is in the source that is being
2026        compiled (which of course may be different). I have changed it back to:
2028          #include "pcre.h"
2030        I have a vague recollection that the change was concerned with compiling in
2031        different directories, but in the new build system, that is taken care of
2032        by the VPATH setting the Makefile.
2034     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2035        when the subject happened to end in the byte 0x85 (e.g. if the last
2036        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2037        characters but of course it shouldn't be taken as a newline when it is part
2038        of another character. The bug was that, for an unlimited repeat of . in
2039        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2040        characters when looking for a newline.
2042     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2044     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2045        in debug output.
2047     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2048        long printing in the pcrecpp unittest when running under MinGW.
2050     6. ESC_K was left out of the EBCDIC table.
2052     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2053        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2054        limit also applies to "virtual nesting" when a pattern is recursive, and in
2055        this case 1000 isn't so big. I have been able to remove this limit at the
2056        expense of backing off one optimization in certain circumstances. Normally,
2057        when pcre_exec() would call its internal match() function recursively and
2058        immediately return the result unconditionally, it uses a "tail recursion"
2059        feature to save stack. However, when a subpattern that can match an empty
2060        string has an unlimited repetition quantifier, it no longer makes this
2061        optimization. That gives it a stack frame in which to save the data for
2062        checking that an empty string has been matched. Previously this was taken
2063        from the 1000-entry workspace that had been reserved. So now there is no
2064        explicit limit, but more stack is used.
2066     8. Applied Daniel's patches to solve problems with the import/export magic
2067        syntax that is required for Windows, and which was going wrong for the
2068        pcreposix and pcrecpp parts of the library. These were overlooked when this
2069        problem was solved for the main library.
2071     9. There were some crude static tests to avoid integer overflow when computing
2072        the size of patterns that contain repeated groups with explicit upper
2073        limits. As the maximum quantifier is 65535, the maximum group length was
2074        set at 30,000 so that the product of these two numbers did not overflow a
2075        32-bit integer. However, it turns out that people want to use groups that
2076        are longer than 30,000 bytes (though not repeat them that many times).
2077        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2078        made it possible to implement the integer overflow checks in a much more
2079        dynamic way, which I have now done. The artificial limitation on group
2080        length has been removed - we now have only the limit on the total length of
2081        the compiled pattern, which depends on the LINK_SIZE setting.
2083    10. Fixed a bug in the documentation for get/copy named substring when
2084        duplicate names are permitted. If none of the named substrings are set, the
2085        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2086        empty string.
2088    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2089        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2090        because the ] is interpreted as the first data character and the
2091        terminating ] is not found. PCRE has been made compatible with Perl in this
2092        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2093        cause memory overwriting.
2095    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2096        string has been matched (to stop an infinite loop). It was not recognizing
2097        a conditional subpattern that could match an empty string if that
2098        subpattern was within another subpattern. For example, it looped when
2099        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
2100        condition was not nested. This bug has been fixed.
2102    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2103        past the start of the subject in the presence of bytes with the top bit
2104        set, for example "\x8aBCD".
2106    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2107        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2109    14. Optimized (?!) to (*FAIL).
2111    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2112        This restricts code points to be within the range 0 to 0x10FFFF, excluding
2113        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2114        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2115        does: it's just the validity check that is more restrictive.
2117    16. Inserted checks for integer overflows during escape sequence (backslash)
2118        processing, and also fixed erroneous offset values for syntax errors during
2119        backslash processing.
2121    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2122        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2124    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2125        caused an overrun.
2127    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2128        something other than just ASCII characters) inside a group that had an
2129        unlimited repeat caused a loop at compile time (while checking to see
2130        whether the group could match an empty string).
2132    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2133        [\P{Any}] did so. (Error in the code for printing property names.)
2135    21. An orphan \E inside a character class could cause a crash.
2137    22. A repeated capturing bracket such as (A)? could cause a wild memory
2138        reference during compilation.
2140    23. There are several functions in pcre_compile() that scan along a compiled
2141        expression for various reasons (e.g. to see if it's fixed length for look
2142        behind). There were bugs in these functions when a repeated \p or \P was
2143        present in the pattern. These operators have additional parameters compared
2144        with \d, etc, and these were not being taken into account when moving along
2145        the compiled data. Specifically:
2147        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2148            length.
2150        (b) An item such as \pL+ within a repeated group could cause crashes or
2151            loops.
2153        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2154            "reference to non-existent subpattern" error.
2156        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2158    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2159        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2161    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2163    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2164        character were causing crashes (broken optimization).
2166    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2167        \p or \P) caused a compile-time loop.
2169    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2170        break. For example, the unstudied pattern [\r\n]A does not match the string
2171        "\r\nA" because change 7.0/46 below moves the current point on by two
2172        characters after failing to match at the start. However, the pattern \nA
2173        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2174        the same is true. There doesn't seem any very clean way out of this, but
2175        what I have chosen to do makes the common cases work: PCRE now takes note
2176        of whether there can be an explicit match for \r or \n anywhere in the
2177        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2178        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2179        pattern has explicit CR or LF references.
2181    29. Added (*CR) etc for changing newline setting at start of pattern.
2184    Version 7.2 19-Jun-07
2185  ---------------------  ---------------------
2187   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 21  Version 7.2 01-May-07 Line 2201  Version 7.2 01-May-07
2201      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
2202      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
2203      in all cases.      in all cases.
2205   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
2207      (a) (?-n) (where n is a string of digits) is a relative subroutine or      (a) (?-n) (where n is a string of digits) is a relative subroutine or
2208          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
2210      (b) (?+n) is also a relative subroutine call; it refers to the nth next      (b) (?+n) is also a relative subroutine call; it refers to the nth next
2211          to be opened parentheses.          to be opened parentheses.
2213      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
2214          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
2216      (d) \K resets the start of the current match so that everything before      (d) \K resets the start of the current match so that everything before
2217          is not part of it.          is not part of it.
2219   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and      (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2221        (f) \g{name} is another synonym - part of Perl 5.10's unification of
2222   8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not          reference syntax.
2223      terminating or by crashing. Diagnosed by Viktor Griph; it was in the code  
2224        (g) (?| introduces a group in which the numbering of parentheses in each
2225            alternative starts with the same number.
2227        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2229     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2232     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
2233        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2234      for detecting groups that can match an empty string.      for detecting groups that can match an empty string.
2236     9. A pattern with a very large number of alternatives (more than several
2237        hundred) was running out of internal workspace during the pre-compile
2238        phase, where pcre_compile() figures out how much memory will be needed. A
2239        bit of new cunning has reduced the workspace needed for groups with
2240        alternatives. The 1000-alternative test pattern now uses 12 bytes of
2241        workspace instead of running out of the 4096 that are available.
2243    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2245    11. Applied patch from Google to remove an optimization that didn't quite work.
2246        The report of the bug said:
2248          pcrecpp::RE("a*").FullMatch("aaa") matches, while
2249          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2250          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2252    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2253        it matched the wrong number of bytes.
2256  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
2257  ---------------------  ---------------------

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