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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.5 12-Nov-07  Version 8.32
5    ------------
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
11    Version 8.31 06-July-2012
12    -------------------------
14    1.  Fixing a wrong JIT test case and some compiler warnings.
16    2.  Removed a bashism from the RunTest script.
18    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
19        to unsigned type, result still unsigned" that was given by an MS compiler
20        on encountering the code "-sizeof(xxx)".
22    4.  Partial matching support is added to the JIT compiler.
24    5.  Fixed several bugs concerned with partial matching of items that consist
25        of more than one character:
27        (a) /^(..)\1/ did not partially match "aba" because checking references was
28            done on an "all or nothing" basis. This also applied to repeated
29            references.
31        (b) \R did not give a hard partial match if \r was found at the end of the
32            subject.
34        (c) \X did not give a hard partial match after matching one or more
35            characters at the end of the subject.
37        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
38            a partial match for the string "\r".
40        (e) When newline was set to CRLF, the metacharacter "." did not recognize
41            a partial match for a CR character at the end of the subject string.
43    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
44        running pcretest, the text "(JIT)" added to the output whenever JIT is
45        actually used to run the match.
47    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
48        or /S+[+] with a digit between 1 and 7.
50    8.  OP_NOT now supports any UTF character not just single-byte ones.
52    9.  (*MARK) control verb is now supported by the JIT compiler.
54    10. The command "./RunTest list" lists the available tests without actually
55        running any of them. (Because I keep forgetting what they all are.)
59    12. Applied a (slightly modified) user-supplied patch that improves performance
60        when the heap is used for recursion (compiled with --disable-stack-for-
61        recursion). Instead of malloc and free for each heap frame each time a
62        logical recursion happens, frames are retained on a chain and re-used where
63        possible. This sometimes gives as much as 30% improvement.
65    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
66        call.
68    14. As documented, (*COMMIT) is now confined to within a positive assertion.
70    15. It is now possible to link pcretest with libedit as an alternative to
71        libreadline.
73    16. (*COMMIT) control verb is now supported by the JIT compiler.
75    17. The Unicode data tables have been updated to Unicode 6.1.0.
77    18. Added --file-list option to pcregrep.
79    19. Added binary file support to pcregrep, including the -a, --binary-files,
80        -I, and --text options.
82    20. The madvise function is renamed for posix_madvise for QNX compatibility
83        reasons. Fixed by Giuseppe D'Angelo.
85    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
87    22. Changed the option for creating symbolic links for 16-bit man pages from
88        -s to -sf so that re-installing does not cause issues.
90    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
92    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
93        matches in certain environments (the workspace was not being correctly
94        retained). Also added to pcre_dfa_exec() a simple plausibility check on
95        some of the workspace data at the beginning of a restart.
97    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
98        was not doing so when it should - probably a typo introduced by SVN 528
99        (change 8.10/14).
101    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
102        \w+ when the character tables indicated that \x{c4} was a word character.
103        There were several related cases, all because the tests for doing a table
104        lookup were testing for characters less than 127 instead of 255.
106    27. If a pattern contains capturing parentheses that are not used in a match,
107        their slots in the ovector are set to -1. For those that are higher than
108        any matched groups, this happens at the end of processing. In the case when
109        there were back references that the ovector was too small to contain
110        (causing temporary malloc'd memory to be used during matching), and the
111        highest capturing number was not used, memory off the end of the ovector
112        was incorrectly being set to -1. (It was using the size of the temporary
113        memory instead of the true size.)
115    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
116        ovector size, it uses memory at the end of the block that it has got.
118    29. Check for an overlong MARK name and give an error at compile time. The
119        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
121    30. JIT compiler update.
123    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
124        Rill for the patch.
126    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
128    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
130    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
131        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
132        was enabled.
134    35. Improve JIT code generation for greedy plus quantifier.
136    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
137        1 to "aa" instead of to an empty string. The bug affected repeated groups
138        that could potentially match an empty string.
140    37. Optimizing single character iterators in JIT.
142    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
143        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
144        codepoints that are too big for the mode are faulted, and in a UTF mode,
145        disallowed codepoints are also faulted.
147    39. If PCRE was compiled with UTF support, in three places in the DFA
148        matcher there was code that should only have been obeyed in UTF mode, but
149        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
150        processing when bytes with values greater than 127 were present. In 16-bit
151        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
152        both cases the values are those that cannot be the first data item in a UTF
153        character. The three items that might have provoked this were recursions,
154        possessively repeated groups, and atomic groups.
156    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
157        and pcregrep, because some OS require shared objects to be explicitly
158        passed to ld, causing the link step to fail if they are not.
160    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
161        mode, patterns that started with \h* or \R* might be incorrectly matched.
164    Version 8.30 04-February-2012
165    -----------------------------
167    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
168        name is defined in ctype.h.
170    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
171        only in quite long subpatterns.
173    3.  Removed the function pcre_info(), which has been obsolete and deprecated
174        since it was replaced by pcre_fullinfo() in February 2000.
176    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
177        match a (*MARK), and the match failed at the start of the subject, a
178        reference to memory before the start of the subject could occur. This bug
179        was introduced by fix 17 of release 8.21.
181    5.  A reference to an unset group with zero minimum repetition was giving
182        totally wrong answers (in non-JavaScript-compatibility mode). For example,
183        /(another)?(\1?)test/ matched against "hello world test". This bug was
184        introduced in release 8.13.
186    6.  Add support for 16-bit character strings (a large amount of work involving
187        many changes and refactorings).
189    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
190        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
191        from a file.
193    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
194        rounding is not applied in this particular case).
196    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
197        if they appear, or are escaped, in patterns.
199    10. Get rid of a number of -Wunused-but-set-variable warnings.
201    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
202        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
203        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
204        also returns the mark "x". This bug applied to capturing parentheses,
205        non-capturing parentheses, and atomic parentheses. It also applied to some
206        assertions.
208    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
209        information out of configure.ac instead of relying on pcre.h.generic, which
210        is not stored in the repository.
212    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
213        -lreadline.
215    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
217    15. Applied Graycode's patch to put the top-level frame on the stack rather
218        than the heap when not using the stack for recursion. This gives a
219        performance improvement in many cases when recursion is not deep.
221    16. Experimental code added to "pcretest -C" to output the stack frame size.
224    Version 8.21 12-Dec-2011
225    ------------------------
227    1.  Updating the JIT compiler.
229    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
230        are added as well.
232    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
233        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
234        calling _pcre_jit_exec. Some extra comments are added.
236    4.  (*MARK) settings inside atomic groups that do not contain any capturing
237        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
238        was introduced by change 18 for 8.20.
240    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
241        ECMA-262 standard.
243    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
244        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
245        This bug was probably introduced by change 9 of 8.13.
247    7.  While fixing 6 above, I noticed that a number of other items were being
248        incorrectly rejected as "not fixed length". This arose partly because newer
249        opcodes had not been added to the fixed-length checking code. I have (a)
250        corrected the bug and added tests for these items, and (b) arranged for an
251        error to occur if an unknown opcode is encountered while checking for fixed
252        length instead of just assuming "not fixed length". The items that were
253        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
254        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
255        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
257    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
258        being incorrectly compiled and would have given unpredicatble results.
260    9.  A possessively repeated subpattern with minimum repeat count greater than
261        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
262        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
263        the first (A) could occur when it should not.
265    10. Add a cast and remove a redundant test from the code.
267    11. JIT should use pcre_malloc/pcre_free for allocation.
269    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
270        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
271        is anything other than /usr, -L is still shown).
273    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
275    14. Perl does not support \N without a following name in a [] class; PCRE now
276        also gives an error.
278    15. If a forward reference was repeated with an upper limit of around 2000,
279        it caused the error "internal error: overran compiling workspace". The
280        maximum number of forward references (including repeats) was limited by the
281        internal workspace, and dependent on the LINK_SIZE. The code has been
282        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
283        the default depends on LINK_SIZE. There is a new upper limit (for safety)
284        of around 200,000 forward references. While doing this, I also speeded up
285        the filling in of repeated forward references.
287    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
288        incorrectly expecting the subject to contain another "a" after the start.
290    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
291        in the match, the SKIP should be ignored. This was not happening; instead
292        the SKIP was being treated as NOMATCH. For patterns such as
293        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
294        tested.
296    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
297        now much more compatible with Perl, in particular in cases where the result
298        is a non-match for a non-anchored pattern. For example, if
299        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
300        "m", where previously it did not return a name. A side effect of this
301        change is that for partial matches, the last encountered mark name is
302        returned, as for non matches. A number of tests that were previously not
303        Perl-compatible have been moved into the Perl-compatible test files. The
304        refactoring has had the pleasing side effect of removing one argument from
305        the match() function, thus reducing its stack requirements.
307    19. If the /S+ option was used in pcretest to study a pattern using JIT,
308        subsequent uses of /S (without +) incorrectly behaved like /S+.
310    21. Retrieve executable code size support for the JIT compiler and fixing
311        some warnings.
313    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
314        not work when the shorter character appeared right at the end of the
315        subject string.
317    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
318        systems.
320    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
321        output it when the /M option is used in pcretest.
323    25. The CheckMan script was not being included in the distribution. Also, added
324        an explicit "perl" to run Perl scripts from the PrepareRelease script
325        because this is reportedly needed in Windows.
327    26. If study data was being save in a file and studying had not found a set of
328        "starts with" bytes for the pattern, the data written to the file (though
329        never used) was taken from uninitialized memory and so caused valgrind to
330        complain.
332    27. Updated RunTest.bat as provided by Sheri Pierce.
334    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
336    29. Computation of memory usage for the table of capturing group names was
337        giving an unnecessarily large value.
340    Version 8.20 21-Oct-2011
341    ------------------------
343    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
344        a POSIX class. After further experiments with Perl, which convinced me that
345        Perl has bugs and confusions, a closing square bracket is no longer allowed
346        in a POSIX name. This bug also affected patterns with classes that started
347        with full stops.
349    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
350        captured substring, but while checking the failing first alternative,
351        substring 1 is temporarily captured. If the output vector supplied to
352        pcre_exec() was not big enough for this capture, the yield of the function
353        was still zero ("insufficient space for captured substrings"). This cannot
354        be totally fixed without adding another stack variable, which seems a lot
355        of expense for a edge case. However, I have improved the situation in cases
356        such as /(a)(b)x|abc/ matched against "abc", where the return code
357        indicates that fewer than the maximum number of slots in the ovector have
358        been set.
360    3.  Related to (2) above: when there are more back references in a pattern than
361        slots in the output vector, pcre_exec() uses temporary memory during
362        matching, and copies in the captures as far as possible afterwards. It was
363        using the entire output vector, but this conflicts with the specification
364        that only 2/3 is used for passing back captured substrings. Now it uses
365        only the first 2/3, for compatibility. This is, of course, another edge
366        case.
368    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
369        main code base, and can be used by building with --enable-jit. When this is
370        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
371        runtime --no-jit option is given.
373    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
374        ovector, the return from the function was zero, implying that there were
375        other matches that did not fit. The correct "exactly full" value is now
376        returned.
378    6.  If a subpattern that was called recursively or as a subroutine contained
379        (*PRUNE) or any other control that caused it to give a non-standard return,
380        invalid errors such as "Error -26 (nested recursion at the same subject
381        position)" or even infinite loops could occur.
383    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
384        computing the minimum length on reaching *ACCEPT, and so ended up with the
385        wrong value of 1 rather than 0. Further investigation indicates that
386        computing a minimum subject length in the presence of *ACCEPT is difficult
387        (think back references, subroutine calls), and so I have changed the code
388        so that no minimum is registered for a pattern that contains *ACCEPT.
390    8.  If (*THEN) was present in the first (true) branch of a conditional group,
391        it was not handled as intended. [But see 16 below.]
393    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
394        Sheri Pierce.
396    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
397        the first byte in a match must be "a".
399    11. Change 17 for 8.13 increased the recursion depth for patterns like
400        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
401        pattern contains any instances of (*THEN). If it does not, the old
402        optimizations are restored. It would be nice to do this on a per-group
403        basis, but at the moment that is not feasible.
405    12. In some environments, the output of pcretest -C is CRLF terminated. This
406        broke RunTest's code that checks for the link size. A single white space
407        character after the value is now allowed for.
409    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
410        For "fr", it uses the Windows-specific input and output files.
412    14. If (*THEN) appeared in a group that was called recursively or as a
413        subroutine, it did not work as intended. [But see next item.]
415    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
416        pattern fragments (but not containing any | characters). If A and B are
417        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
418        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
419        D. In other words, Perl considers parentheses that do not contain any |
420        characters to be part of a surrounding alternative, whereas PCRE was
421        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
422        differently. PCRE now behaves in the same way as Perl, except in the case
423        of subroutine/recursion calls such as (?1) which have in any case always
424        been different (but PCRE had them first :-).
426    16. Related to 15 above: Perl does not treat the | in a conditional group as
427        creating alternatives. Such a group is treated in the same way as an
428        ordinary group without any | characters when processing (*THEN). PCRE has
429        been changed to match Perl's behaviour.
431    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
432        RunGrepTest script failed.
434    18. Change 22 for version 13 caused atomic groups to use more stack. This is
435        inevitable for groups that contain captures, but it can lead to a lot of
436        stack use in large patterns. The old behaviour has been restored for atomic
437        groups that do not contain any capturing parentheses.
439    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
440        suppress the check for a minimum subject length at run time. (If it was
441        given to pcre_exec() or pcre_dfa_exec() it did work.)
443    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
444        fail to work when decoding hex characters in data strings in EBCDIC
445        environments.
447    21. It appears that in at least one Mac OS environment, the isxdigit() function
448        is implemented as a macro that evaluates to its argument more than once,
449        contravening the C 90 Standard (I haven't checked a later standard). There
450        was an instance in pcretest which caused it to go wrong when processing
451        \x{...} escapes in subject strings. The has been rewritten to avoid using
452        things like p++ in the argument of isxdigit().
455    Version 8.13 16-Aug-2011
456    ------------------------
458    1.  The Unicode data tables have been updated to Unicode 6.0.0.
460    2.  Two minor typos in pcre_internal.h have been fixed.
462    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
463        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
464        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
466    4.  There were a number of related bugs in the code for matching backrefences
467        caselessly in UTF-8 mode when codes for the characters concerned were
468        different numbers of bytes. For example, U+023A and U+2C65 are an upper
469        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
470        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
471        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
472        2-byte code at the end of the subject (it thought there wasn't enough data
473        left).
475    5.  Comprehensive information about what went wrong is now returned by
476        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
477        as the output vector has at least 2 elements. The offset of the start of
478        the failing character and a reason code are placed in the vector.
480    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
481        now returned is for the first byte of the failing character, instead of the
482        last byte inspected. This is an incompatible change, but I hope it is small
483        enough not to be a problem. It makes the returned offset consistent with
484        pcre_exec() and pcre_dfa_exec().
486    7.  pcretest now gives a text phrase as well as the error number when
487        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
488        failure, the offset and reason code are output.
490    8.  When \R was used with a maximizing quantifier it failed to skip backwards
491        over a \r\n pair if the subsequent match failed. Instead, it just skipped
492        back over a single character (\n). This seems wrong (because it treated the
493        two characters as a single entity when going forwards), conflicts with the
494        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
495        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
496        has been changed.
498    9.  Some internal refactoring has changed the processing so that the handling
499        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
500        time (the PCRE_DOTALL option was changed this way some time ago: version
501        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
502        which was always a bit of a fudge. It also means that there is one less
503        argument for the match() function, which reduces its stack requirements
504        slightly. This change also fixes an incompatibility with Perl: the pattern
505        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
507    10. More internal refactoring has drastically reduced the number of recursive
508        calls to match() for possessively repeated groups such as (abc)++ when
509        using pcre_exec().
511    11. While implementing 10, a number of bugs in the handling of groups were
512        discovered and fixed:
514        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
515        (a|)*(?1) gave a compile-time internal error.
516        ((a|)+)+  did not notice that the outer group could match an empty string.
517        (^a|^)+   was not marked as anchored.
518        (.*a|.*)+ was not marked as matching at start or after a newline.
520    12. Yet more internal refactoring has removed another argument from the match()
521        function. Special calls to this function are now indicated by setting a
522        value in a variable in the "match data" data block.
524    13. Be more explicit in pcre_study() instead of relying on "default" for
525        opcodes that mean there is no starting character; this means that when new
526        ones are added and accidentally left out of pcre_study(), testing should
527        pick them up.
529    14. The -s option of pcretest has been documented for ages as being an old
530        synonym of -m (show memory usage). I have changed it to mean "force study
531        for every regex", that is, assume /S for every regex. This is similar to -i
532        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
533        using it. It makes it easier to run collections of tests with and without
534        study enabled, and thereby test pcre_study() more easily. All the standard
535        tests are now run with and without -s (but some patterns can be marked as
536        "never study" - see 20 below).
538    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
539        restoration of the capturing data to the outer values was not happening
540        correctly.
542    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
543        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
544        pattern had matched an empty string, and so incorrectly returned a no
545        match.
547    17. There was optimizing code for the last branch of non-capturing parentheses,
548        and also for the obeyed branch of a conditional subexpression, which used
549        tail recursion to cut down on stack usage. Unfortunately, now that there is
550        the possibility of (*THEN) occurring in these branches, tail recursion is
551        no longer possible because the return has to be checked for (*THEN). These
552        two optimizations have therefore been removed. [But see 8.20/11 above.]
554    18. If a pattern containing \R was studied, it was assumed that \R always
555        matched two bytes, thus causing the minimum subject length to be
556        incorrectly computed because \R can also match just one byte.
558    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
559        was incorrectly computed.
561    20. If /S is present twice on a test pattern in pcretest input, it now
562        *disables* studying, thereby overriding the use of -s on the command line
563        (see 14 above). This is necessary for one or two tests to keep the output
564        identical in both cases.
566    21. When (*ACCEPT) was used in an assertion that matched an empty string and
567        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
569    22. When an atomic group that contained a capturing parenthesis was
570        successfully matched, but the branch in which it appeared failed, the
571        capturing was not being forgotten if a higher numbered group was later
572        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
573        group 1 to "a", when in fact it should be unset. This applied to multi-
574        branched capturing and non-capturing groups, repeated or not, and also to
575        positive assertions (capturing in negative assertions does not happen
576        in PCRE) and also to nested atomic groups.
578    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
579        subject after a captured substring, to make it easier to tell which of a
580        number of identical substrings has been captured.
582    24. The way atomic groups are processed by pcre_exec() has been changed so that
583        if they are repeated, backtracking one repetition now resets captured
584        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
585        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
586        "aaa". Previously, it would have been "a". As part of this code
587        refactoring, the way recursive calls are handled has also been changed.
589    25. If an assertion condition captured any substrings, they were not passed
590        back unless some other capturing happened later. For example, if
591        (?(?=(a))a) was matched against "a", no capturing was returned.
593    26. When studying a pattern that contained subroutine calls or assertions,
594        the code for finding the minimum length of a possible match was handling
595        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
596        group 1 called group 2 while simultaneously a separate group 2 called group
597        1). A stack overflow occurred in this case. I have fixed this by limiting
598        the recursion depth to 10.
600    27. Updated RunTest.bat in the distribution to the version supplied by Tom
601        Fortmann. This supports explicit test numbers on the command line, and has
602        argument validation and error reporting.
604    28. An instance of \X with an unlimited repeat could fail if at any point the
605        first character it looked at was a mark character.
607    29. Some minor code refactoring concerning Unicode properties and scripts
608        should reduce the stack requirement of match() slightly.
610    30. Added the '=' option to pcretest to check the setting of unused capturing
611        slots at the end of the pattern, which are documented as being -1, but are
612        not included in the return count.
614    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
615        compiled something random. Now it gives a compile-time error (as does
616        Perl).
618    32. A *MARK encountered during the processing of a positive assertion is now
619        recorded and passed back (compatible with Perl).
621    33. If --only-matching or --colour was set on a pcregrep call whose pattern
622        had alternative anchored branches, the search for a second match in a line
623        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
624        matched the line "0102" twice. The same bug affected patterns that started
625        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
626        twice.
628    34. Previously, PCRE did not allow quantification of assertions. However, Perl
629        does, and because of capturing effects, quantifying parenthesized
630        assertions may at times be useful. Quantifiers are now allowed for
631        parenthesized assertions.
633    35. A minor code tidy in pcre_compile() when checking options for \R usage.
635    36. \g was being checked for fancy things in a character class, when it should
636        just be a literal "g".
638    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
639        appearance of a nested POSIX class supersedes an apparent external class.
640        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
641        unescaped square brackets may also appear as part of class names. For
642        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
643        more like Perl. (But see 8.20/1 above.)
645    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
646        was because it thought it was \N{name}, which is not supported).
648    39. Add minix to OS list not supporting the -S option in pcretest.
650    40. PCRE tries to detect cases of infinite recursion at compile time, but it
651        cannot analyze patterns in sufficient detail to catch mutual recursions
652        such as ((?1))((?2)). There is now a runtime test that gives an error if a
653        subgroup is called recursively as a subpattern for a second time at the
654        same position in the subject string. In previous releases this might have
655        been caught by the recursion limit, or it might have run out of stack.
657    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
658        happen only once. PCRE was, however incorrectly giving a compile time error
659        "recursive call could loop indefinitely" because it cannot analyze the
660        pattern in sufficient detail. The compile time test no longer happens when
661        PCRE is compiling a conditional subpattern, but actual runaway loops are
662        now caught at runtime (see 40 above).
664    42. It seems that Perl allows any characters other than a closing parenthesis
665        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
666        has been changed to be the same.
668    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
669        as not to get warnings when autogen.sh is called. Also changed
670        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
672    44. To help people who use pcregrep to scan files containing exceedingly long
673        lines, the following changes have been made:
675        (a) The default value of the buffer size parameter has been increased from
676            8K to 20K. (The actual buffer used is three times this size.)
678        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
679            PCRE is built.
681        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
682            to be set at run time.
684        (d) Numerical values in pcregrep options can be followed by K or M, for
685            example --buffer-size=50K.
687        (e) If a line being scanned overflows pcregrep's buffer, an error is now
688            given and the return code is set to 2.
690    45. Add a pointer to the latest mark to the callout data block.
692    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
693        partial match of an empty string instead of no match. This was specific to
694        the use of ".".
696    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
697        complete match instead of a partial match. This bug was dependent on both
698        the PCRE_UTF8 and PCRE_DOTALL options being set.
700    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
701        starting byte set, because \b was not being ignored.
704    Version 8.12 15-Jan-2011
705    ------------------------
707    1.  Fixed some typos in the markup of the man pages, and wrote a script that
708        checks for such things as part of the documentation building process.
710    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
711        --match-limit and --recursion-limit options (added for 8.11). In
712        particular, this made one of the standard tests fail. (The integer value
713        went into the wrong half of a long int.)
715    3.  If the --colour option was given to pcregrep with -v (invert match), it
716        did strange things, either producing crazy output, or crashing. It should,
717        of course, ignore a request for colour when reporting lines that do not
718        match.
720    4.  Another pcregrep bug caused similar problems if --colour was specified with
721        -M (multiline) and the pattern match finished with a line ending.
723    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
724        matched in multiline mode, the following line was shown as part of the
725        match. This seems wrong, so I have changed it.
727    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
728        the check for further matches in the same line (so they could be coloured)
729        to overrun the end of the current line. If another match was found, it was
730        incorrectly shown (and then shown again when found in the next line).
732    7.  If pcregrep was compiled under Windows, there was a reference to the
733        function pcregrep_exit() before it was defined. I am assuming this was
734        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
735        reported by a user. I've moved the definition above the reference.
738    Version 8.11 10-Dec-2010
739    ------------------------
741    1.  (*THEN) was not working properly if there were untried alternatives prior
742        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
743        backtracked to try for "b" instead of moving to the next alternative branch
744        at the same level (in this case, to look for "c"). The Perl documentation
745        is clear that when (*THEN) is backtracked onto, it goes to the "next
746        alternative in the innermost enclosing group".
748    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
749        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
750        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
751        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
752        (*THEN).
754    3.  If \s appeared in a character class, it removed the VT character from
755        the class, even if it had been included by some previous item, for example
756        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
757        of \s, but is part of the POSIX "space" class.)
759    4.  A partial match never returns an empty string (because you can always
760        match an empty string at the end of the subject); however the checking for
761        an empty string was starting at the "start of match" point. This has been
762        changed to the "earliest inspected character" point, because the returned
763        data for a partial match starts at this character. This means that, for
764        example, /(?<=abc)def/ gives a partial match for the subject "abc"
765        (previously it gave "no match").
767    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
768        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
769        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
770        has an implication that the given string is incomplete (because a partial
771        match is preferred over a full match). For this reason, these items now
772        give a partial match in this situation. [Aside: previously, the one case
773        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
774        match rather than a full match, which was wrong by the old rules, but is
775        now correct.]
777    6.  There was a bug in the handling of #-introduced comments, recognized when
778        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
779        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
780        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
781        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
782        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
783        places in pcre_compile().
785    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
786        comments when looking ahead for named forward references to subpatterns,
787        the only newline sequence it recognized was NL. It now handles newlines
788        according to the set newline convention.
790    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
791        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
792        cater for a lack of strerror(). These oversights have been fixed.
794    9.  Added --match-limit and --recursion-limit to pcregrep.
796    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
798    11. When the -o option was used, pcregrep was setting a return code of 1, even
799        when matches were found, and --line-buffered was not being honoured.
801    12. Added an optional parentheses number to the -o and --only-matching options
802        of pcregrep.
804    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
805        can match an empty string. The code to do it in pcretest and pcredemo
806        needed fixing:
808        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
809            only one byte after an empty string match just before CRLF (this case
810            just got forgotten; "any" and "anycrlf" were OK).
812        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
813            mode when an empty string match preceded an ASCII character followed by
814            a non-ASCII character. (The code for advancing by one character rather
815            than one byte was nonsense.)
817        (c) The pcredemo.c sample program did not have any code at all to handle
818            the cases when CRLF is a valid newline sequence.
820    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
821        as a starting offset was within the subject string. There is now a new
822        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
823        negative or greater than the length of the string. In order to test this,
824        pcretest is extended to allow the setting of negative starting offsets.
826    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
827        starting offset points to the beginning of a UTF-8 character was
828        unnecessarily clumsy. I tidied it up.
830    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
831        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
833    17. Nobody had reported that the --include_dir option, which was added in
834        release 7.7 should have been called --include-dir (hyphen, not underscore)
835        for compatibility with GNU grep. I have changed it to --include-dir, but
836        left --include_dir as an undocumented synonym, and the same for
837        --exclude-dir, though that is not available in GNU grep, at least as of
838        release 2.5.4.
840    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
841        characters from a string of bytes) have been redefined so as not to use
842        loops, in order to improve performance in some environments. At the same
843        time, I abstracted some of the common code into auxiliary macros to save
844        repetition (this should not affect the compiled code).
846    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
847        compile-time error is now given if \c is not followed by an ASCII
848        character, that is, a byte less than 128. (In EBCDIC mode, the code is
849        different, and any byte value is allowed.)
851    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
852        START_OPTIMIZE option, which is now allowed at compile time - but just
853        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
854        to pcregrep and other applications that have no direct access to PCRE
855        options. The new /Y option in pcretest sets this option when calling
856        pcre_compile().
858    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
859        back references. Groups containing recursive back references were forced to
860        be atomic by that change, but in the case of named groups, the amount of
861        memory required was incorrectly computed, leading to "Failed: internal
862        error: code overflow". This has been fixed.
864    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
865        pcretest.c, to avoid build problems in some Borland environments.
868    Version 8.10 25-Jun-2010
869    ------------------------
871    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
872        THEN.
874    2.  (*ACCEPT) was not working when inside an atomic group.
876    3.  Inside a character class, \B is treated as a literal by default, but
877        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
878        causes the error). The code is unchanged, but I tidied the documentation.
880    4.  Inside a character class, PCRE always treated \R and \X as literals,
881        whereas Perl faults them if its -w option is set. I have changed PCRE so
882        that it faults them when PCRE_EXTRA is set.
884    5.  Added support for \N, which always matches any character other than
885        newline. (It is the same as "." when PCRE_DOTALL is not set.)
887    6.  When compiling pcregrep with newer versions of gcc which may have
888        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
889        declared with attribute warn_unused_result" were given. Just casting the
890        result to (void) does not stop the warnings; a more elaborate fudge is
891        needed. I've used a macro to implement this.
893    7.  Minor change to pcretest.c to avoid a compiler warning.
895    8.  Added four artifical Unicode properties to help with an option to make
896        \s etc use properties (see next item). The new properties are: Xan
897        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
899    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
900        use Unicode properties. (*UCP) at the start of a pattern can be used to set
901        this option. Modified pcretest to add /W to test this facility. Added
902        REG_UCP to make it available via the POSIX interface.
904    10. Added --line-buffered to pcregrep.
906    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
907        studied, and the match started with a letter with a code point greater than
908        127 whose first byte was different to the first byte of the other case of
909        the letter, the other case of this starting letter was not recognized
910        (#976).
912    12. If a pattern that was studied started with a repeated Unicode property
913        test, for example, \p{Nd}+, there was the theoretical possibility of
914        setting up an incorrect bitmap of starting bytes, but fortunately it could
915        not have actually happened in practice until change 8 above was made (it
916        added property types that matched character-matching opcodes).
918    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
919        possible starting bytes for non-anchored patterns.
921    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
922        \R, and also a number of cases that involve Unicode properties, both
923        explicit and implicit when PCRE_UCP is set.
925    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
926        input, it could crash or give wrong results if characters with values
927        greater than 0xc0 were present in the subject string. (Detail: it assumed
928        UTF-8 input when processing these items.)
930    16. Added a lot of (int) casts to avoid compiler warnings in systems where
931        size_t is 64-bit (#991).
933    17. Added a check for running out of memory when PCRE is compiled with
934        --disable-stack-for-recursion (#990).
936    18. If the last data line in a file for pcretest does not have a newline on
937        the end, a newline was missing in the output.
939    19. The default pcre_chartables.c file recognizes only ASCII characters (values
940        less than 128) in its various bitmaps. However, there is a facility for
941        generating tables according to the current locale when PCRE is compiled. It
942        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
943        characters, are recognized by isspace() and therefore were getting set in
944        these tables, and indeed these tables seem to approximate to ISO 8859. This
945        caused a problem in UTF-8 mode when pcre_study() was used to create a list
946        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
947        which of course cannot start UTF-8 characters. I have changed the code so
948        that only real ASCII characters (less than 128) and the correct starting
949        bytes for UTF-8 encodings are set for characters greater than 127 when in
950        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
951        altogether.)
953    20. Added the /T option to pcretest so as to be able to run tests with non-
954        standard character tables, thus making it possible to include the tests
955        used for 19 above in the standard set of tests.
957    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
958        reference to a subpattern the other side of a comment that contains an
959        opening parenthesis caused either an internal compiling error, or a
960        reference to the wrong subpattern.
963    Version 8.02 19-Mar-2010
964    ------------------------
966    1.  The Unicode data tables have been updated to Unicode 5.2.0.
968    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
969        configured.
971    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
972        original author of that file, following a query about its status.
974    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
975        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
977    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
978        quantifier applied to a forward-referencing subroutine call, could compile
979        incorrect code or give the error "internal error: previously-checked
980        referenced subpattern not found".
982    6.  Both MS Visual Studio and Symbian OS have problems with initializing
983        variables to point to external functions. For these systems, therefore,
984        pcre_malloc etc. are now initialized to local functions that call the
985        relevant global functions.
987    7.  There were two entries missing in the vectors called coptable and poptable
988        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
989        I've fixed the data, and added a kludgy way of testing at compile time that
990        the lengths are correct (equal to the number of opcodes).
992    8.  Following on from 7, I added a similar kludge to check the length of the
993        eint vector in pcreposix.c.
995    9.  Error texts for pcre_compile() are held as one long string to avoid too
996        much relocation at load time. To find a text, the string is searched,
997        counting zeros. There was no check for running off the end of the string,
998        which could happen if a new error number was added without updating the
999        string.
1001    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1003    11. \K was not working if it appeared in an atomic group or in a group that
1004        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1005        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1006        the assertion is positive, but not if it is negative.
1008    12. Change 11 fortuitously reduced the size of the stack frame used in the
1009        "match()" function of pcre_exec.c by one pointer. Forthcoming
1010        implementation of support for (*MARK) will need an extra pointer on the
1011        stack; I have reserved it now, so that the stack frame size does not
1012        decrease.
1014    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1015        item in branch that calls a recursion is a subroutine call - as in the
1016        second branch in the above example - was incorrectly given the compile-
1017        time error "recursive call could loop indefinitely" because pcre_compile()
1018        was not correctly checking the subroutine for matching a non-empty string.
1020    14. The checks for overrunning compiling workspace could trigger after an
1021        overrun had occurred. This is a "should never occur" error, but it can be
1022        triggered by pathological patterns such as hundreds of nested parentheses.
1023        The checks now trigger 100 bytes before the end of the workspace.
1025    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1028    Version 8.01 19-Jan-2010
1029    ------------------------
1031    1.  If a pattern contained a conditional subpattern with only one branch (in
1032        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1033        computed the wrong minimum data length (which is of course zero for such
1034        subpatterns). This could cause incorrect "no match" results.
1036    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1037        the pattern is reset in the first branch, pcre_compile() failed with
1038        "internal error: code overflow at offset...". This happened only when
1039        the reset was to the original external option setting. (An optimization
1040        abstracts leading options settings into an external setting, which was the
1041        cause of this.)
1043    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1044        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1045        assertion pattern did not match (meaning that the assertion was true), it
1046        was incorrectly treated as false if the SKIP had been reached during the
1047        matching. This also applied to assertions used as conditions.
1049    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1050        assertion subpattern, including such a pattern used as a condition,
1051        unpredictable results occurred, instead of the error return
1054    5.  The C++ GlobalReplace function was not working like Perl for the special
1055        situation when an empty string is matched. It now does the fancy magic
1056        stuff that is necessary.
1058    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1059        removed. (These were left over from very, very early versions of PCRE.)
1061    7.  Some cosmetic changes to the code to make life easier when compiling it
1062        as part of something else:
1064        (a) Change DEBUG to PCRE_DEBUG.
1066        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1067            called "current" as "current_branch", to prevent a collision with the
1068            Linux macro when compiled as a kernel module.
1070        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1071            prevent a collision with the Linux macro when compiled as a kernel
1072            module.
1074    8.  In pcre_compile() there are some checks for integer overflows that used to
1075        cast potentially large values to (double). This has been changed to that
1076        when building, a check for int64_t is made, and if it is found, it is used
1077        instead, thus avoiding the use of floating point arithmetic. (There is no
1078        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1079        double.
1081    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1082        2005 (difference between two addresses compared to an unsigned value).
1084    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1085        custom one, because of the following reported problem in Windows:
1087          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1088              under Win32.
1089          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1090              therefore missing the function definition.
1091          - The compiler thus generates a "C" signature for the test function.
1092          - The linker fails to find the "C" function.
1093          - PCRE fails to configure if asked to do so against libbz2.
1095    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1096        messages were output:
1098          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1099          rerunning libtoolize, to keep the correct libtool macros in-tree.
1100          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1102        I have done both of these things.
1104    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1105        most of the time, it *can* run out if it is given a pattern that contains a
1106        runaway infinite recursion. I updated the discussion in the pcrestack man
1107        page.
1109    13. Now that we have gone to the x.xx style of version numbers, the minor
1110        version may start with zero. Using 08 or 09 is a bad idea because users
1111        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1112        interpreted as invalid octal numbers. I've updated the previous comment in
1113        configure.ac, and also added a check that gives an error if 08 or 09 are
1114        used.
1116    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1117        causing partial matching to fail when the end of the subject matched \W
1118        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1120    15. There were some discrepancies between the declarations in pcre_internal.h
1121        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1122        their definitions. The declarations used "const uschar *" and the
1123        definitions used USPTR. Even though USPTR is normally defined as "const
1124        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1125        reported that: "This difference in casting confuses some C++ compilers, for
1126        example, SunCC recognizes above declarations as different functions and
1127        generates broken code for hbpcre." I have changed the declarations to use
1128        USPTR.
1130    16. GNU libtool is named differently on some systems. The autogen.sh script now
1131        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1132        (FreeBSD).
1134    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1135        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1136        comment: "Figure out how to create a longlong from a string: strtoll and
1137        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1138        instance, but it only takes 2 args instead of 3!"
1140    18. A subtle bug concerned with back references has been fixed by a change of
1141        specification, with a corresponding code fix. A pattern such as
1142        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1143        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1144        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1145        same bug. Such groups have to be quantified to be useful, or contained
1146        inside another quantified group. (If there's no repetition, the reference
1147        can never match.) The problem arises because, having left the group and
1148        moved on to the rest of the pattern, a later failure that backtracks into
1149        the group uses the captured value from the final iteration of the group
1150        rather than the correct earlier one. I have fixed this in PCRE by forcing
1151        any group that contains a reference to itself to be an atomic group; that
1152        is, there cannot be any backtracking into it once it has completed. This is
1153        similar to recursive and subroutine calls.
1156    Version 8.00 19-Oct-09
1157    ----------------------
1159    1.  The table for translating pcre_compile() error codes into POSIX error codes
1160        was out-of-date, and there was no check on the pcre_compile() error code
1161        being within the table. This could lead to an OK return being given in
1162        error.
1164    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1165        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1166        in a Windows environment.
1168    3.  The pcregrep --count option prints the count for each file even when it is
1169        zero, as does GNU grep. However, pcregrep was also printing all files when
1170        --files-with-matches was added. Now, when both options are given, it prints
1171        counts only for those files that have at least one match. (GNU grep just
1172        prints the file name in this circumstance, but including the count seems
1173        more useful - otherwise, why use --count?) Also ensured that the
1174        combination -clh just lists non-zero counts, with no names.
1176    4.  The long form of the pcregrep -F option was incorrectly implemented as
1177        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1178        but it seems right to fix it, and I didn't think it was worth preserving
1179        the old behaviour.
1181    5.  The command line items --regex=pattern and --regexp=pattern were not
1182        recognized by pcregrep, which required --regex pattern or --regexp pattern
1183        (with a space rather than an '='). The man page documented the '=' forms,
1184        which are compatible with GNU grep; these now work.
1186    6.  No libpcreposix.pc file was created for pkg-config; there was just
1187        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1189    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1190        when UCP support is not needed, by modifying the Python script that
1191        generates it from Unicode data files. This should not matter if the module
1192        is correctly used as a library, but I received one complaint about 50K of
1193        unwanted data. My guess is that the person linked everything into his
1194        program rather than using a library. Anyway, it does no harm.
1196    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1197        was a minimum greater than 1 for a wide character in a possessive
1198        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1199        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1200        character. Chaos in the form of incorrect output or a compiling loop could
1201        result.
1203    9.  The restrictions on what a pattern can contain when partial matching is
1204        requested for pcre_exec() have been removed. All patterns can now be
1205        partially matched by this function. In addition, if there are at least two
1206        slots in the offset vector, the offset of the earliest inspected character
1207        for the match and the offset of the end of the subject are set in them when
1208        PCRE_ERROR_PARTIAL is returned.
1210    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1211        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1212        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1213        and may be more useful for multi-segment matching.
1215    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1216        used to be given if ever the end of the subject was reached; now it is
1217        given only if matching could not proceed because another character was
1218        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1219        string "Z", which now yields "no match" instead of "partial match". In the
1220        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1221        final character ended with (*FAIL).
1223    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1224        if the pattern had a "must contain" character that was already found in the
1225        earlier partial match, unless partial matching was again requested. For
1226        example, with the pattern /dog.(body)?/, the "must contain" character is
1227        "g". If the first part-match was for the string "dog", restarting with
1228        "sbody" failed. This bug has been fixed.
1230    13. The string returned by pcre_dfa_exec() after a partial match has been
1231        changed so that it starts at the first inspected character rather than the
1232        first character of the match. This makes a difference only if the pattern
1233        starts with a lookbehind assertion or \b or \B (\K is not supported by
1234        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1235        matching functions compatible, and I think it's the right thing to do.
1237    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1238        so that the demonstration program is easily available in environments where
1239        PCRE has not been installed from source.
1241    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1242        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1243        library.
1245    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1246        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1247        is not the first non-POSIX option to be added. Clearly some people find
1248        these options useful.
1250    17. If a caller to the POSIX matching function regexec() passes a non-zero
1251        value for nmatch with a NULL value for pmatch, the value of
1252        nmatch is forced to zero.
1254    18. RunGrepTest did not have a test for the availability of the -u option of
1255        the diff command, as RunTest does. It now checks in the same way as
1256        RunTest, and also checks for the -b option.
1258    19. If an odd number of negated classes containing just a single character
1259        interposed, within parentheses, between a forward reference to a named
1260        subpattern and the definition of the subpattern, compilation crashed with
1261        an internal error, complaining that it could not find the referenced
1262        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1263        [The bug was that it was starting one character too far in when skipping
1264        over the character class, thus treating the ] as data rather than
1265        terminating the class. This meant it could skip too much.]
1267    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1268        /g option in pcretest when the pattern contains \K, which makes it possible
1269        to have an empty string match not at the start, even when the pattern is
1270        anchored. Updated pcretest and pcredemo to use this option.
1272    21. If the maximum number of capturing subpatterns in a recursion was greater
1273        than the maximum at the outer level, the higher number was returned, but
1274        with unset values at the outer level. The correct (outer level) value is
1275        now given.
1277    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1278        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1279        make it do so. The string so far is captured, making this feature
1280        compatible with Perl.
1282    23. The tests have been re-organized, adding tests 11 and 12, to make it
1283        possible to check the Perl 5.10 features against Perl 5.10.
1285    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1286        pattern matches a fixed length string. PCRE did not allow this; now it
1287        does. Neither allows recursion.
1289    25. I finally figured out how to implement a request to provide the minimum
1290        length of subject string that was needed in order to match a given pattern.
1291        (It was back references and recursion that I had previously got hung up
1292        on.) This code has now been added to pcre_study(); it finds a lower bound
1293        to the length of subject needed. It is not necessarily the greatest lower
1294        bound, but using it to avoid searching strings that are too short does give
1295        some useful speed-ups. The value is available to calling programs via
1296        pcre_fullinfo().
1298    26. While implementing 25, I discovered to my embarrassment that pcretest had
1299        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1300        study optimizations had never been tested with that matching function.
1301        Oops. What is worse, even when it was passed study data, there was a bug in
1302        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1303        were also very few tests of studied patterns with pcre_dfa_exec().
1305    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1306        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1307        on the other side of the coin, they are no longer allowed to have different
1308        names, because these cannot be distinguished in PCRE, and this has caused
1309        confusion. (This is a difference from Perl.)
1311    28. When duplicate subpattern names are present (necessarily with different
1312        numbers, as required by 27 above), and a test is made by name in a
1313        conditional pattern, either for a subpattern having been matched, or for
1314        recursion in such a pattern, all the associated numbered subpatterns are
1315        tested, and the overall condition is true if the condition is true for any
1316        one of them. This is the way Perl works, and is also more like the way
1317        testing by number works.
1320    Version 7.9 11-Apr-09
1321    ---------------------
1323    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1324        (pcretest), all targets were linked against these libraries. This included
1325        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1326        libraries. This caused unwanted dependencies to be created. This problem
1327        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1328        pcretest is linked with readline.
1330    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1331        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1332        moved outside it again, because FALSE and TRUE are already defined in AIX,
1333        but BOOL is not.
1335    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1336        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1338    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1339        hyphens) following file names and line numbers when outputting matching
1340        lines. This is not true; no spaces are inserted. I have also clarified the
1341        wording for the --colour (or --color) option.
1343    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1344        was not coloured; this is different to GNU grep, so I have changed it to be
1345        the same.
1347    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1348        each matching line was coloured. Now it goes on to look for further matches
1349        of any of the test patterns, which is the same behaviour as GNU grep.
1351    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1352        doesn't make sense to accept an empty string match in pcregrep, so I have
1353        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1354        seems to be how GNU grep behaves.
1356    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1357        start or after a newline", because the conditional assertion was not being
1358        correctly handled. The rule now is that both the assertion and what follows
1359        in the first alternative must satisfy the test.
1361    9.  If auto-callout was enabled in a pattern with a conditional group whose
1362        condition was an assertion, PCRE could crash during matching, both with
1363        pcre_exec() and pcre_dfa_exec().
1365    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1366        used for matching.
1368    11. Unicode property support in character classes was not working for
1369        characters (bytes) greater than 127 when not in UTF-8 mode.
1371    12. Added the -M command line option to pcretest.
1373    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1375    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1377    16. Added comments and documentation about mis-use of no_arg in the C++
1378        wrapper.
1380    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1381        from Martin Jerabek that uses macro names for all relevant character and
1382        string constants.
1384    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1385        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1386        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1387        these, but not everybody uses configure.
1389    19. A conditional group that had only one branch was not being correctly
1390        recognized as an item that could match an empty string. This meant that an
1391        enclosing group might also not be so recognized, causing infinite looping
1392        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1393        with the subject "ab", where knowledge that the repeated group can match
1394        nothing is needed in order to break the loop.
1396    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1397        exec(), but without supplying a callout function, matching went wrong.
1399    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1400        leak if the size of the offset vector was greater than 30. When the vector
1401        is smaller, the saved offsets during recursion go onto a local stack
1402        vector, but for larger vectors malloc() is used. It was failing to free
1403        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1404        error, in fact).
1406    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1407        heapframe that is used only when UTF-8 support is enabled. This caused no
1408        problem, but was untidy.
1410    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1411        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1412        included within another project.
1414    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1415        slightly modified by me:
1417          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1418              not building pcregrep.
1420          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1421              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1423    25. Forward references, both numeric and by name, in patterns that made use of
1424        duplicate group numbers, could behave incorrectly or give incorrect errors,
1425        because when scanning forward to find the reference group, PCRE was not
1426        taking into account the duplicate group numbers. A pattern such as
1427        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1429    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1430        the feature of a custom pointer more persuasive (as requested by a user).
1432    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1433        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1434        pre-defined.
1436    28. Added support for (*UTF8) at the start of a pattern.
1438    29. Arrange for flags added by the "release type" setting in CMake to be shown
1439        in the configuration summary.
1442    Version 7.8 05-Sep-08
1443    ---------------------
1445    1.  Replaced UCP searching code with optimized version as implemented for Ad
1446        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1447        stage table and inline lookup instead of a function, giving speed ups of 2
1448        to 5 times on some simple patterns that I tested. Permission was given to
1449        distribute the MultiStage2.py script that generates the tables (it's not in
1450        the tarball, but is in the Subversion repository).
1452    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1453        scripts.
1455    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1456        a group with a zero qualifier. The result of the study could be incorrect,
1457        or the function might crash, depending on the pattern.
1459    4.  Caseless matching was not working for non-ASCII characters in back
1460        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1461        It now works when Unicode Property Support is available.
1463    5.  In pcretest, an escape such as \x{de} in the data was always generating
1464        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1465        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1466        truncation.
1468    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1470    7.  Added two (int) casts to pcregrep when printing the difference of two
1471        pointers, in case they are 64-bit values.
1473    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1474        test 2 if it fails.
1476    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1477        and a #define of that name to empty if it is not externally set. This is to
1478        allow users of MSVC to set it if necessary.
1480    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1481        the convenience functions in the pcre_get.c source file.
1483    11. An option change at the start of a pattern that had top-level alternatives
1484        could cause overwriting and/or a crash. This command provoked a crash in
1485        some environments:
1487          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1489        This potential security problem was recorded as CVE-2008-2371.
1491    12. For a pattern where the match had to start at the beginning or immediately
1492        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1493        pcre_dfa_exec() could read past the end of the passed subject if there was
1494        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1495        pcretest so that it places the subject at the end of its malloc-ed buffer.
1497    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1498        exec() might read past the end of the data buffer in UTF-8 mode.
1500    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1501        the data contained the byte 0x85 as part of a UTF-8 character within its
1502        first line. This applied both to normal and DFA matching.
1504    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1505        /^[^d]*?$/8 failed to match "abc".
1507    16. Added a missing copyright notice to pcrecpp_internal.h.
1509    17. Make it more clear in the documentation that values returned from
1510        pcre_exec() in ovector are byte offsets, not character counts.
1512    18. Tidied a few places to stop certain compilers from issuing warnings.
1514    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1515        supplied by Stefan Weber. I made a further small update for 7.8 because
1516        there is a change of source arrangements: the pcre_searchfuncs.c module is
1517        replaced by pcre_ucd.c.
1520    Version 7.7 07-May-08
1521    ---------------------
1523    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1524        a string to a long long, pretend we don't even have a long long." This is
1525        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1527    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1528        pre-7.6 versions, which defined a global no_arg variable instead of putting
1529        it in the RE class. (See also #8 below.)
1531    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1532        Lopes.
1534    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1536        (1) The include/exclude patterns were being applied to the whole pathnames
1537            of files, instead of just to the final components.
1539        (2) If there was more than one level of directory, the subdirectories were
1540            skipped unless they satisfied the include/exclude conditions. This is
1541            inconsistent with GNU grep (and could even be seen as contrary to the
1542            pcregrep specification - which I improved to make it absolutely clear).
1543            The action now is always to scan all levels of directory, and just
1544            apply the include/exclude patterns to regular files.
1546    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1547        --exclude_dir in the tests to avoid scanning .svn directories.
1549    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1550        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1551        doesn't support NULs in patterns.
1553    7.  Added some missing "const"s to declarations of static tables in
1554        pcre_compile.c and pcre_dfa_exec.c.
1556    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1557        caused by fix #2  above. (Subsequently also a second patch to fix the
1558        first patch. And a third patch - this was a messy problem.)
1560    9.  Applied Craig's patch to remove the use of push_back().
1562    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1563        matching function regexec().
1565    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1566        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1567        references. PCRE supports relative numbers with this syntax (I don't think
1568        Oniguruma does).
1570    12. Previously, a group with a zero repeat such as (...){0} was completely
1571        omitted from the compiled regex. However, this means that if the group
1572        was called as a subroutine from elsewhere in the pattern, things went wrong
1573        (an internal error was given). Such groups are now left in the compiled
1574        pattern, with a new opcode that causes them to be skipped at execution
1575        time.
1577    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1578        to the way PCRE behaves:
1580        (a) A lone ] character is dis-allowed (Perl treats it as data).
1582        (b) A back reference to an unmatched subpattern matches an empty string
1583            (Perl fails the current match path).
1585        (c) A data ] in a character class must be notated as \] because if the
1586            first data character in a class is ], it defines an empty class. (In
1587            Perl it is not possible to have an empty class.) The empty class []
1588            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1589            The negative empty class [^] matches any one character, independently
1590            of the DOTALL setting.
1592    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1593        non-existent subpattern following a character class starting with ']' and
1594        containing () gave an internal compiling error instead of "reference to
1595        non-existent subpattern". Fortunately, when the pattern did exist, the
1596        compiled code was correct. (When scanning forwards to check for the
1597        existencd of the subpattern, it was treating the data ']' as terminating
1598        the class, so got the count wrong. When actually compiling, the reference
1599        was subsequently set up correctly.)
1601    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1602        it was being rejected as not supported by pcre_dfa_exec(), even though
1603        other assertions are supported. I have made pcre_dfa_exec() support
1604        (*FAIL).
1606    16. The implementation of 13c above involved the invention of a new opcode,
1607        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1608        cannot be changed at match time, I realized I could make a small
1609        improvement to matching performance by compiling OP_ALLANY instead of
1610        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1611        on the OP_ANY path.
1613    17. Compiling pcretest on Windows with readline support failed without the
1614        following two fixes: (1) Make the unistd.h include conditional on
1615        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1617    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1618        ncurses library to be included for pcretest when ReadLine support is
1619        requested, but also to allow for it to be overridden. This patch came from
1620        Daniel Bergström.
1622    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1623        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1624        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1625        spotting this.
1628    Version 7.6 28-Jan-08
1629    ---------------------
1631    1.  A character class containing a very large number of characters with
1632        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1633        overflow.
1635    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1636        HAVE_LONG_LONG is not defined.
1638    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1639        bring them up to date and include new features. This patch includes:
1641        - Fixed PH's badly added libz and libbz2 support.
1642        - Fixed a problem with static linking.
1643        - Added pcredemo. [But later removed - see 7 below.]
1644        - Fixed dftables problem and added an option.
1645        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1646            HAVE_LONG_LONG.
1647        - Added readline support for pcretest.
1648        - Added an listing of the option settings after cmake has run.
1650    4.  A user submitted a patch to Makefile that makes it easy to create
1651        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1652        Makefile.am that cause it to include this special target, without
1653        affecting anything else. Note that the same mingw target plus all
1654        the other distribution libraries and programs are now supported
1655        when configuring with CMake (see 6 below) instead of with
1656        Configure/Make.
1658    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1659        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1660        exported in the Windows port". It has not yet been confirmed that the patch
1661        solves the problem, but it does no harm.
1663    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1664        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1665        with CMake, and also correct the comment about stack recursion.
1667    7.  Remove the automatic building of pcredemo from the ./configure system and
1668        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1669        of a program that users should build themselves after PCRE is installed, so
1670        building it automatically is not really right. What is more, it gave
1671        trouble in some build environments.
1673    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1676    Version 7.5 10-Jan-08
1677  ---------------------  ---------------------
1679  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1680      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1682  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1683      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1684      included.      included.
1686  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
1687      [:^space:].      [:^space:].
1689    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1690        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1691        I have changed it.
1693    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1694        first named subpattern) and a construct such as (?&a) would reference the
1695        first named subpattern whose name started with "a" (in other words, the
1696        length check was missing). Both these problems are fixed. "Subpattern name
1697        expected" is now given for (?&) (a zero-length name), and this patch also
1698        makes it give the same error for \k'' (previously it complained that that
1699        was a reference to a non-existent subpattern).
1701    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1702        this is right because (?- can be followed by option settings as well as by
1703        digits. I have, however, made the messages clearer.
1705    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1706        than the number used in the conditional) now cause a compile-time error.
1707        This is actually not compatible with Perl, which accepts such patterns, but
1708        treats the conditional as always being FALSE (as PCRE used to), but it
1709        seems to me that giving a diagnostic is better.
1711    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1712        and messages.
1714    9.  Fix two occurrences of "backslash" in comments that should have been
1715        "backspace".
1717    10. Remove two redundant lines of code that can never be obeyed (their function
1718        was moved elsewhere).
1720    11. The program that makes PCRE's Unicode character property table had a bug
1721        which caused it to generate incorrect table entries for sequences of
1722        characters that have the same character type, but are in different scripts.
1723        It amalgamated them into a single range, with the script of the first of
1724        them. In other words, some characters were in the wrong script. There were
1725        thirteen such cases, affecting characters in the following ranges:
1727          U+002b0 - U+002c1
1728          U+0060c - U+0060d
1729          U+0061e - U+00612
1730          U+0064b - U+0065e
1731          U+0074d - U+0076d
1732          U+01800 - U+01805
1733          U+01d00 - U+01d77
1734          U+01d9b - U+01dbf
1735          U+0200b - U+0200f
1736          U+030fc - U+030fe
1737          U+03260 - U+0327f
1738          U+0fb46 - U+0fbb1
1739          U+10450 - U+1049d
1741    12. The -o option (show only the matching part of a line) for pcregrep was not
1742        compatible with GNU grep in that, if there was more than one match in a
1743        line, it showed only the first of them. It now behaves in the same way as
1744        GNU grep.
1746    13. If the -o and -v options were combined for pcregrep, it printed a blank
1747        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1748        does the same. The return code can be used to tell if there were any
1749        non-matching lines.
1751    14. Added --file-offsets and --line-offsets to pcregrep.
1753    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1754        infinitely looping recursion. The bug was that positive lookaheads were not
1755        being skipped when checking for a possible empty match (negative lookaheads
1756        and both kinds of lookbehind were skipped).
1758    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1759        inclusion of <windows.h> to before rather than after the definition of
1760        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1762    17. Specifying a possessive quantifier with a specific limit for a Unicode
1763        character property caused pcre_compile() to compile bad code, which led at
1764        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1765        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1766        caused the error; without that there was no problem.
1768    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1770    19. Added --enable-pcretest-libreadline.
1772    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1773        RE::GlobalReplace(). As a result, the number of replacements returned was
1774        double what it should be. I removed one of the increments, but Craig sent a
1775        later patch that removed the other one (the right fix) and added unit tests
1776        that check the return values (which was not done before).
1778    21. Several CMake things:
1780        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1781            the names libpcre and libpcreposix, not just pcre and pcreposix.
1783        (2) The above change means that pcretest and pcregrep are now correctly
1784            linked with the newly-built libraries, not previously installed ones.
1788    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1789        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1790        UTF-8 newline character). The key issue is that the pattern starts .*;
1791        this means that the match must be either at the beginning, or after a
1792        newline. The bug was in the code for advancing after a failed match and
1793        checking that the new position followed a newline. It was not taking
1794        account of UTF-8 characters correctly.
1796    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1797        character classes. PCRE was not treating the sequence [:...:] as a
1798        character class unless the ... were all letters. Perl, however, seems to
1799        allow any characters between [: and :], though of course it rejects as
1800        unknown any "names" that contain non-letters, because all the known class
1801        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1802        for example, whereas PCRE did not - it did not recognize a POSIX character
1803        class. This seemed a bit dangerous, so the code has been changed to be
1804        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1805        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1806        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1807        Perl does, and where it didn't before.
1809    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1810        Windows environments %n is disabled by default.
1813  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07
1814  ---------------------  ---------------------

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