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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.3 17-Aug-07  Version 8.33 xx-xxxx-201x
5    -------------------------
7    1.  Added 'U' to some constants that are compared to unsigned integers, to
8        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
9        variables that are added to signed variables, to ensure the result is
10        signed and can be negated.
12    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
13        CMake config files.
15    3.  Revise the creation of config.h.generic so that all boolean macros are
16        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
17        overriding via -D on the command line possible.
19    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
20        to unsigned int is reported to make a quite noticeable speed difference in
21        a specific Windows environment. Testing on Linux did also appear to show
22        some benefit (and it is clearly not harmful). Also fixed the definition of
23        Xop which should be unsigned.
25    5.  Related to (4), changing the definition of the intermediate variable cc
26        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
27        improvements.
29    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
30        unnecessary spaces.
32    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
33        and later.
35    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
38    Version 8.32 30-November-2012
39    -----------------------------
41    1.  Improved JIT compiler optimizations for first character search and single
42        character iterators.
44    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
45        Patch by Daniel Richard G.
47    3.  Single character iterator optimizations in the JIT compiler.
49    4.  Improved JIT compiler optimizations for character ranges.
51    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
52        Reported by Giuseppe D'Angelo.
54    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
55        of a line, was being set incorrectly in cases where .* appeared inside
56        atomic brackets at the start of a pattern, or where there was a subsequent
57        *PRUNE or *SKIP.
59    7.  Improved instruction cache flush for POWER/PowerPC.
60        Patch by Daniel Richard G.
62    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
63        grep:
65        (a) There is now no limit to the number of patterns to be matched.
67        (b) An error is given if a pattern is too long.
69        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
70            are now supported.
72        (d) --exclude-from and --include-from (multiple use) have been added.
74        (e) Exclusions and inclusions now apply to all files and directories, not
75            just to those obtained from scanning a directory recursively.
77        (f) Multiple uses of -f and --file-list are now supported.
79        (g) In a Windows environment, the default for -d has been changed from
80            "read" (the GNU grep default) to "skip", because otherwise the presence
81            of a directory in the file list provokes an error.
83        (h) The documentation has been revised and clarified in places.
85    9.  Improve the matching speed of capturing brackets.
87    10. Changed the meaning of \X so that it now matches a Unicode extended
88        grapheme cluster.
90    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
91        out POSIX threads when JIT support is configured.
93    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
95    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
96        structure could go wrong in environments where size_t is not the same size
97        as int.
99    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
100        set.
102    15. The EBCDIC support had decayed; later updates to the code had included
103        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
104        general tidy up of EBCDIC-related issues, and the documentation was also
105        not quite right. There is now a test that can be run on ASCII systems to
106        check some of the EBCDIC-related things (but is it not a full test).
108    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
109        in a small tidy to the code.
111    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
113    18. If the --only-matching (-o) option in pcregrep is specified multiple
114        times, each one causes appropriate output. For example, -o1 -o2 outputs the
115        substrings matched by the 1st and 2nd capturing parentheses. A separating
116        string can be specified by --om-separator (default empty).
118    19. Improving the first n character searches.
120    20. Turn case lists for horizontal and vertical white space into macros so that
121        they are defined only once.
123    21. This set of changes together give more compatible Unicode case-folding
124        behaviour for characters that have more than one other case when UCP
125        support is available.
127        (a) The Unicode property table now has offsets into a new table of sets of
128            three or more characters that are case-equivalent. The MultiStage2.py
129            script that generates these tables (the pcre_ucd.c file) now scans
130            CaseFolding.txt instead of UnicodeData.txt for character case
131            information.
133        (b) The code for adding characters or ranges of characters to a character
134            class has been abstracted into a generalized function that also handles
135            case-independence. In UTF-mode with UCP support, this uses the new data
136            to handle characters with more than one other case.
138        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
139            whose other case is greater than 256 are now correctly matched
140            caselessly. Previously, the high codepoint matched the low one, but not
141            vice versa.
143        (d) The processing of \h, \H, \v, and \ in character classes now makes use
144            of the new class addition function, using character lists defined as
145            macros alongside the case definitions of 20 above.
147        (e) Caseless back references now work with characters that have more than
148            one other case.
150        (f) General caseless matching of characters with more than one other case
151            is supported.
153    22. Unicode character properties were updated from Unicode 6.2.0
155    23. Improved CMake support under Windows. Patch by Daniel Richard G.
157    24. Add support for 32-bit character strings, and UTF-32
159    25. Major JIT compiler update (code refactoring and bugfixing).
160        Experimental Sparc 32 support is added.
162    26. Applied a modified version of Daniel Richard G's patch to create
163        pcre.h.generic and config.h.generic by "make" instead of in the
164        PrepareRelease script.
166    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
167        pcre_compile.c when checking for a zero character.
169    28. Introducing a native interface for JIT. Through this interface, the compiled
170        machine code can be directly executed. The purpose of this interface is to
171        provide fast pattern matching, so several sanity checks are not performed.
172        However, feature tests are still performed. The new interface provides
173        1.4x speedup compared to the old one.
175    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
176        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
177        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
179    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
180        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
181        the "old" RFC 2279). Instead, it ended up passing a negative length to
182        pcre_exec().
184    31. Add support for GCC's visibility feature to hide internal functions.
186    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
187        "unknown -C option" after outputting 0 or 1.
189    33. There is now support for generating a code coverage report for the test
190        suite in environments where gcc is the compiler and lcov is installed. This
191        is mainly for the benefit of the developers.
193    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
194        unaddressable using valgrind annotations, allowing valgrind to detect
195        invalid memory accesses. This is mainly for the benefit of the developers.
197    25. (*UTF) can now be used to start a pattern in any of the three libraries.
199    26. Give configure error if --enable-cpp but no C++ compiler found.
202    Version 8.31 06-July-2012
203    -------------------------
205    1.  Fixing a wrong JIT test case and some compiler warnings.
207    2.  Removed a bashism from the RunTest script.
209    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
210        to unsigned type, result still unsigned" that was given by an MS compiler
211        on encountering the code "-sizeof(xxx)".
213    4.  Partial matching support is added to the JIT compiler.
215    5.  Fixed several bugs concerned with partial matching of items that consist
216        of more than one character:
218        (a) /^(..)\1/ did not partially match "aba" because checking references was
219            done on an "all or nothing" basis. This also applied to repeated
220            references.
222        (b) \R did not give a hard partial match if \r was found at the end of the
223            subject.
225        (c) \X did not give a hard partial match after matching one or more
226            characters at the end of the subject.
228        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
229            a partial match for the string "\r".
231        (e) When newline was set to CRLF, the metacharacter "." did not recognize
232            a partial match for a CR character at the end of the subject string.
234    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
235        running pcretest, the text "(JIT)" added to the output whenever JIT is
236        actually used to run the match.
238    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
239        or /S+[+] with a digit between 1 and 7.
241    8.  OP_NOT now supports any UTF character not just single-byte ones.
243    9.  (*MARK) control verb is now supported by the JIT compiler.
245    10. The command "./RunTest list" lists the available tests without actually
246        running any of them. (Because I keep forgetting what they all are.)
250    12. Applied a (slightly modified) user-supplied patch that improves performance
251        when the heap is used for recursion (compiled with --disable-stack-for-
252        recursion). Instead of malloc and free for each heap frame each time a
253        logical recursion happens, frames are retained on a chain and re-used where
254        possible. This sometimes gives as much as 30% improvement.
256    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
257        call.
259    14. As documented, (*COMMIT) is now confined to within a positive assertion.
261    15. It is now possible to link pcretest with libedit as an alternative to
262        libreadline.
264    16. (*COMMIT) control verb is now supported by the JIT compiler.
266    17. The Unicode data tables have been updated to Unicode 6.1.0.
268    18. Added --file-list option to pcregrep.
270    19. Added binary file support to pcregrep, including the -a, --binary-files,
271        -I, and --text options.
273    20. The madvise function is renamed for posix_madvise for QNX compatibility
274        reasons. Fixed by Giuseppe D'Angelo.
276    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
278    22. Changed the option for creating symbolic links for 16-bit man pages from
279        -s to -sf so that re-installing does not cause issues.
281    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
283    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
284        matches in certain environments (the workspace was not being correctly
285        retained). Also added to pcre_dfa_exec() a simple plausibility check on
286        some of the workspace data at the beginning of a restart.
288    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
289        was not doing so when it should - probably a typo introduced by SVN 528
290        (change 8.10/14).
292    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
293        \w+ when the character tables indicated that \x{c4} was a word character.
294        There were several related cases, all because the tests for doing a table
295        lookup were testing for characters less than 127 instead of 255.
297    27. If a pattern contains capturing parentheses that are not used in a match,
298        their slots in the ovector are set to -1. For those that are higher than
299        any matched groups, this happens at the end of processing. In the case when
300        there were back references that the ovector was too small to contain
301        (causing temporary malloc'd memory to be used during matching), and the
302        highest capturing number was not used, memory off the end of the ovector
303        was incorrectly being set to -1. (It was using the size of the temporary
304        memory instead of the true size.)
306    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
307        ovector size, it uses memory at the end of the block that it has got.
309    29. Check for an overlong MARK name and give an error at compile time. The
310        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
312    30. JIT compiler update.
314    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
315        Rill for the patch.
317    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
319    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
321    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
322        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
323        was enabled.
325    35. Improve JIT code generation for greedy plus quantifier.
327    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
328        1 to "aa" instead of to an empty string. The bug affected repeated groups
329        that could potentially match an empty string.
331    37. Optimizing single character iterators in JIT.
333    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
334        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
335        codepoints that are too big for the mode are faulted, and in a UTF mode,
336        disallowed codepoints are also faulted.
338    39. If PCRE was compiled with UTF support, in three places in the DFA
339        matcher there was code that should only have been obeyed in UTF mode, but
340        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
341        processing when bytes with values greater than 127 were present. In 16-bit
342        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
343        both cases the values are those that cannot be the first data item in a UTF
344        character. The three items that might have provoked this were recursions,
345        possessively repeated groups, and atomic groups.
347    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
348        and pcregrep, because some OS require shared objects to be explicitly
349        passed to ld, causing the link step to fail if they are not.
351    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
352        mode, patterns that started with \h* or \R* might be incorrectly matched.
355    Version 8.30 04-February-2012
356    -----------------------------
358    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
359        name is defined in ctype.h.
361    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
362        only in quite long subpatterns.
364    3.  Removed the function pcre_info(), which has been obsolete and deprecated
365        since it was replaced by pcre_fullinfo() in February 2000.
367    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
368        match a (*MARK), and the match failed at the start of the subject, a
369        reference to memory before the start of the subject could occur. This bug
370        was introduced by fix 17 of release 8.21.
372    5.  A reference to an unset group with zero minimum repetition was giving
373        totally wrong answers (in non-JavaScript-compatibility mode). For example,
374        /(another)?(\1?)test/ matched against "hello world test". This bug was
375        introduced in release 8.13.
377    6.  Add support for 16-bit character strings (a large amount of work involving
378        many changes and refactorings).
380    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
381        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
382        from a file.
384    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
385        rounding is not applied in this particular case).
387    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
388        if they appear, or are escaped, in patterns.
390    10. Get rid of a number of -Wunused-but-set-variable warnings.
392    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
393        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
394        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
395        also returns the mark "x". This bug applied to capturing parentheses,
396        non-capturing parentheses, and atomic parentheses. It also applied to some
397        assertions.
399    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
400        information out of configure.ac instead of relying on pcre.h.generic, which
401        is not stored in the repository.
403    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
404        -lreadline.
406    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
408    15. Applied Graycode's patch to put the top-level frame on the stack rather
409        than the heap when not using the stack for recursion. This gives a
410        performance improvement in many cases when recursion is not deep.
412    16. Experimental code added to "pcretest -C" to output the stack frame size.
415    Version 8.21 12-Dec-2011
416    ------------------------
418    1.  Updating the JIT compiler.
420    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
421        are added as well.
423    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
424        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
425        calling _pcre_jit_exec. Some extra comments are added.
427    4.  (*MARK) settings inside atomic groups that do not contain any capturing
428        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
429        was introduced by change 18 for 8.20.
431    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
432        ECMA-262 standard.
434    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
435        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
436        This bug was probably introduced by change 9 of 8.13.
438    7.  While fixing 6 above, I noticed that a number of other items were being
439        incorrectly rejected as "not fixed length". This arose partly because newer
440        opcodes had not been added to the fixed-length checking code. I have (a)
441        corrected the bug and added tests for these items, and (b) arranged for an
442        error to occur if an unknown opcode is encountered while checking for fixed
443        length instead of just assuming "not fixed length". The items that were
444        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
445        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
446        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
448    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
449        being incorrectly compiled and would have given unpredicatble results.
451    9.  A possessively repeated subpattern with minimum repeat count greater than
452        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
453        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
454        the first (A) could occur when it should not.
456    10. Add a cast and remove a redundant test from the code.
458    11. JIT should use pcre_malloc/pcre_free for allocation.
460    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
461        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
462        is anything other than /usr, -L is still shown).
464    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
466    14. Perl does not support \N without a following name in a [] class; PCRE now
467        also gives an error.
469    15. If a forward reference was repeated with an upper limit of around 2000,
470        it caused the error "internal error: overran compiling workspace". The
471        maximum number of forward references (including repeats) was limited by the
472        internal workspace, and dependent on the LINK_SIZE. The code has been
473        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
474        the default depends on LINK_SIZE. There is a new upper limit (for safety)
475        of around 200,000 forward references. While doing this, I also speeded up
476        the filling in of repeated forward references.
478    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
479        incorrectly expecting the subject to contain another "a" after the start.
481    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
482        in the match, the SKIP should be ignored. This was not happening; instead
483        the SKIP was being treated as NOMATCH. For patterns such as
484        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
485        tested.
487    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
488        now much more compatible with Perl, in particular in cases where the result
489        is a non-match for a non-anchored pattern. For example, if
490        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
491        "m", where previously it did not return a name. A side effect of this
492        change is that for partial matches, the last encountered mark name is
493        returned, as for non matches. A number of tests that were previously not
494        Perl-compatible have been moved into the Perl-compatible test files. The
495        refactoring has had the pleasing side effect of removing one argument from
496        the match() function, thus reducing its stack requirements.
498    19. If the /S+ option was used in pcretest to study a pattern using JIT,
499        subsequent uses of /S (without +) incorrectly behaved like /S+.
501    21. Retrieve executable code size support for the JIT compiler and fixing
502        some warnings.
504    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
505        not work when the shorter character appeared right at the end of the
506        subject string.
508    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
509        systems.
511    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
512        output it when the /M option is used in pcretest.
514    25. The CheckMan script was not being included in the distribution. Also, added
515        an explicit "perl" to run Perl scripts from the PrepareRelease script
516        because this is reportedly needed in Windows.
518    26. If study data was being save in a file and studying had not found a set of
519        "starts with" bytes for the pattern, the data written to the file (though
520        never used) was taken from uninitialized memory and so caused valgrind to
521        complain.
523    27. Updated RunTest.bat as provided by Sheri Pierce.
525    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
527    29. Computation of memory usage for the table of capturing group names was
528        giving an unnecessarily large value.
531    Version 8.20 21-Oct-2011
532    ------------------------
534    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
535        a POSIX class. After further experiments with Perl, which convinced me that
536        Perl has bugs and confusions, a closing square bracket is no longer allowed
537        in a POSIX name. This bug also affected patterns with classes that started
538        with full stops.
540    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
541        captured substring, but while checking the failing first alternative,
542        substring 1 is temporarily captured. If the output vector supplied to
543        pcre_exec() was not big enough for this capture, the yield of the function
544        was still zero ("insufficient space for captured substrings"). This cannot
545        be totally fixed without adding another stack variable, which seems a lot
546        of expense for a edge case. However, I have improved the situation in cases
547        such as /(a)(b)x|abc/ matched against "abc", where the return code
548        indicates that fewer than the maximum number of slots in the ovector have
549        been set.
551    3.  Related to (2) above: when there are more back references in a pattern than
552        slots in the output vector, pcre_exec() uses temporary memory during
553        matching, and copies in the captures as far as possible afterwards. It was
554        using the entire output vector, but this conflicts with the specification
555        that only 2/3 is used for passing back captured substrings. Now it uses
556        only the first 2/3, for compatibility. This is, of course, another edge
557        case.
559    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
560        main code base, and can be used by building with --enable-jit. When this is
561        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
562        runtime --no-jit option is given.
564    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
565        ovector, the return from the function was zero, implying that there were
566        other matches that did not fit. The correct "exactly full" value is now
567        returned.
569    6.  If a subpattern that was called recursively or as a subroutine contained
570        (*PRUNE) or any other control that caused it to give a non-standard return,
571        invalid errors such as "Error -26 (nested recursion at the same subject
572        position)" or even infinite loops could occur.
574    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
575        computing the minimum length on reaching *ACCEPT, and so ended up with the
576        wrong value of 1 rather than 0. Further investigation indicates that
577        computing a minimum subject length in the presence of *ACCEPT is difficult
578        (think back references, subroutine calls), and so I have changed the code
579        so that no minimum is registered for a pattern that contains *ACCEPT.
581    8.  If (*THEN) was present in the first (true) branch of a conditional group,
582        it was not handled as intended. [But see 16 below.]
584    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
585        Sheri Pierce.
587    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
588        the first byte in a match must be "a".
590    11. Change 17 for 8.13 increased the recursion depth for patterns like
591        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
592        pattern contains any instances of (*THEN). If it does not, the old
593        optimizations are restored. It would be nice to do this on a per-group
594        basis, but at the moment that is not feasible.
596    12. In some environments, the output of pcretest -C is CRLF terminated. This
597        broke RunTest's code that checks for the link size. A single white space
598        character after the value is now allowed for.
600    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
601        For "fr", it uses the Windows-specific input and output files.
603    14. If (*THEN) appeared in a group that was called recursively or as a
604        subroutine, it did not work as intended. [But see next item.]
606    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
607        pattern fragments (but not containing any | characters). If A and B are
608        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
609        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
610        D. In other words, Perl considers parentheses that do not contain any |
611        characters to be part of a surrounding alternative, whereas PCRE was
612        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
613        differently. PCRE now behaves in the same way as Perl, except in the case
614        of subroutine/recursion calls such as (?1) which have in any case always
615        been different (but PCRE had them first :-).
617    16. Related to 15 above: Perl does not treat the | in a conditional group as
618        creating alternatives. Such a group is treated in the same way as an
619        ordinary group without any | characters when processing (*THEN). PCRE has
620        been changed to match Perl's behaviour.
622    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
623        RunGrepTest script failed.
625    18. Change 22 for version 13 caused atomic groups to use more stack. This is
626        inevitable for groups that contain captures, but it can lead to a lot of
627        stack use in large patterns. The old behaviour has been restored for atomic
628        groups that do not contain any capturing parentheses.
630    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
631        suppress the check for a minimum subject length at run time. (If it was
632        given to pcre_exec() or pcre_dfa_exec() it did work.)
634    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
635        fail to work when decoding hex characters in data strings in EBCDIC
636        environments.
638    21. It appears that in at least one Mac OS environment, the isxdigit() function
639        is implemented as a macro that evaluates to its argument more than once,
640        contravening the C 90 Standard (I haven't checked a later standard). There
641        was an instance in pcretest which caused it to go wrong when processing
642        \x{...} escapes in subject strings. The has been rewritten to avoid using
643        things like p++ in the argument of isxdigit().
646    Version 8.13 16-Aug-2011
647    ------------------------
649    1.  The Unicode data tables have been updated to Unicode 6.0.0.
651    2.  Two minor typos in pcre_internal.h have been fixed.
653    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
654        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
655        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
657    4.  There were a number of related bugs in the code for matching backrefences
658        caselessly in UTF-8 mode when codes for the characters concerned were
659        different numbers of bytes. For example, U+023A and U+2C65 are an upper
660        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
661        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
662        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
663        2-byte code at the end of the subject (it thought there wasn't enough data
664        left).
666    5.  Comprehensive information about what went wrong is now returned by
667        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
668        as the output vector has at least 2 elements. The offset of the start of
669        the failing character and a reason code are placed in the vector.
671    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
672        now returned is for the first byte of the failing character, instead of the
673        last byte inspected. This is an incompatible change, but I hope it is small
674        enough not to be a problem. It makes the returned offset consistent with
675        pcre_exec() and pcre_dfa_exec().
677    7.  pcretest now gives a text phrase as well as the error number when
678        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
679        failure, the offset and reason code are output.
681    8.  When \R was used with a maximizing quantifier it failed to skip backwards
682        over a \r\n pair if the subsequent match failed. Instead, it just skipped
683        back over a single character (\n). This seems wrong (because it treated the
684        two characters as a single entity when going forwards), conflicts with the
685        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
686        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
687        has been changed.
689    9.  Some internal refactoring has changed the processing so that the handling
690        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
691        time (the PCRE_DOTALL option was changed this way some time ago: version
692        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
693        which was always a bit of a fudge. It also means that there is one less
694        argument for the match() function, which reduces its stack requirements
695        slightly. This change also fixes an incompatibility with Perl: the pattern
696        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
698    10. More internal refactoring has drastically reduced the number of recursive
699        calls to match() for possessively repeated groups such as (abc)++ when
700        using pcre_exec().
702    11. While implementing 10, a number of bugs in the handling of groups were
703        discovered and fixed:
705        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
706        (a|)*(?1) gave a compile-time internal error.
707        ((a|)+)+  did not notice that the outer group could match an empty string.
708        (^a|^)+   was not marked as anchored.
709        (.*a|.*)+ was not marked as matching at start or after a newline.
711    12. Yet more internal refactoring has removed another argument from the match()
712        function. Special calls to this function are now indicated by setting a
713        value in a variable in the "match data" data block.
715    13. Be more explicit in pcre_study() instead of relying on "default" for
716        opcodes that mean there is no starting character; this means that when new
717        ones are added and accidentally left out of pcre_study(), testing should
718        pick them up.
720    14. The -s option of pcretest has been documented for ages as being an old
721        synonym of -m (show memory usage). I have changed it to mean "force study
722        for every regex", that is, assume /S for every regex. This is similar to -i
723        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
724        using it. It makes it easier to run collections of tests with and without
725        study enabled, and thereby test pcre_study() more easily. All the standard
726        tests are now run with and without -s (but some patterns can be marked as
727        "never study" - see 20 below).
729    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
730        restoration of the capturing data to the outer values was not happening
731        correctly.
733    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
734        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
735        pattern had matched an empty string, and so incorrectly returned a no
736        match.
738    17. There was optimizing code for the last branch of non-capturing parentheses,
739        and also for the obeyed branch of a conditional subexpression, which used
740        tail recursion to cut down on stack usage. Unfortunately, now that there is
741        the possibility of (*THEN) occurring in these branches, tail recursion is
742        no longer possible because the return has to be checked for (*THEN). These
743        two optimizations have therefore been removed. [But see 8.20/11 above.]
745    18. If a pattern containing \R was studied, it was assumed that \R always
746        matched two bytes, thus causing the minimum subject length to be
747        incorrectly computed because \R can also match just one byte.
749    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
750        was incorrectly computed.
752    20. If /S is present twice on a test pattern in pcretest input, it now
753        *disables* studying, thereby overriding the use of -s on the command line
754        (see 14 above). This is necessary for one or two tests to keep the output
755        identical in both cases.
757    21. When (*ACCEPT) was used in an assertion that matched an empty string and
758        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
760    22. When an atomic group that contained a capturing parenthesis was
761        successfully matched, but the branch in which it appeared failed, the
762        capturing was not being forgotten if a higher numbered group was later
763        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
764        group 1 to "a", when in fact it should be unset. This applied to multi-
765        branched capturing and non-capturing groups, repeated or not, and also to
766        positive assertions (capturing in negative assertions does not happen
767        in PCRE) and also to nested atomic groups.
769    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
770        subject after a captured substring, to make it easier to tell which of a
771        number of identical substrings has been captured.
773    24. The way atomic groups are processed by pcre_exec() has been changed so that
774        if they are repeated, backtracking one repetition now resets captured
775        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
776        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
777        "aaa". Previously, it would have been "a". As part of this code
778        refactoring, the way recursive calls are handled has also been changed.
780    25. If an assertion condition captured any substrings, they were not passed
781        back unless some other capturing happened later. For example, if
782        (?(?=(a))a) was matched against "a", no capturing was returned.
784    26. When studying a pattern that contained subroutine calls or assertions,
785        the code for finding the minimum length of a possible match was handling
786        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
787        group 1 called group 2 while simultaneously a separate group 2 called group
788        1). A stack overflow occurred in this case. I have fixed this by limiting
789        the recursion depth to 10.
791    27. Updated RunTest.bat in the distribution to the version supplied by Tom
792        Fortmann. This supports explicit test numbers on the command line, and has
793        argument validation and error reporting.
795    28. An instance of \X with an unlimited repeat could fail if at any point the
796        first character it looked at was a mark character.
798    29. Some minor code refactoring concerning Unicode properties and scripts
799        should reduce the stack requirement of match() slightly.
801    30. Added the '=' option to pcretest to check the setting of unused capturing
802        slots at the end of the pattern, which are documented as being -1, but are
803        not included in the return count.
805    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
806        compiled something random. Now it gives a compile-time error (as does
807        Perl).
809    32. A *MARK encountered during the processing of a positive assertion is now
810        recorded and passed back (compatible with Perl).
812    33. If --only-matching or --colour was set on a pcregrep call whose pattern
813        had alternative anchored branches, the search for a second match in a line
814        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
815        matched the line "0102" twice. The same bug affected patterns that started
816        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
817        twice.
819    34. Previously, PCRE did not allow quantification of assertions. However, Perl
820        does, and because of capturing effects, quantifying parenthesized
821        assertions may at times be useful. Quantifiers are now allowed for
822        parenthesized assertions.
824    35. A minor code tidy in pcre_compile() when checking options for \R usage.
826    36. \g was being checked for fancy things in a character class, when it should
827        just be a literal "g".
829    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
830        appearance of a nested POSIX class supersedes an apparent external class.
831        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
832        unescaped square brackets may also appear as part of class names. For
833        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
834        more like Perl. (But see 8.20/1 above.)
836    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
837        was because it thought it was \N{name}, which is not supported).
839    39. Add minix to OS list not supporting the -S option in pcretest.
841    40. PCRE tries to detect cases of infinite recursion at compile time, but it
842        cannot analyze patterns in sufficient detail to catch mutual recursions
843        such as ((?1))((?2)). There is now a runtime test that gives an error if a
844        subgroup is called recursively as a subpattern for a second time at the
845        same position in the subject string. In previous releases this might have
846        been caught by the recursion limit, or it might have run out of stack.
848    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
849        happen only once. PCRE was, however incorrectly giving a compile time error
850        "recursive call could loop indefinitely" because it cannot analyze the
851        pattern in sufficient detail. The compile time test no longer happens when
852        PCRE is compiling a conditional subpattern, but actual runaway loops are
853        now caught at runtime (see 40 above).
855    42. It seems that Perl allows any characters other than a closing parenthesis
856        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
857        has been changed to be the same.
859    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
860        as not to get warnings when autogen.sh is called. Also changed
861        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
863    44. To help people who use pcregrep to scan files containing exceedingly long
864        lines, the following changes have been made:
866        (a) The default value of the buffer size parameter has been increased from
867            8K to 20K. (The actual buffer used is three times this size.)
869        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
870            PCRE is built.
872        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
873            to be set at run time.
875        (d) Numerical values in pcregrep options can be followed by K or M, for
876            example --buffer-size=50K.
878        (e) If a line being scanned overflows pcregrep's buffer, an error is now
879            given and the return code is set to 2.
881    45. Add a pointer to the latest mark to the callout data block.
883    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
884        partial match of an empty string instead of no match. This was specific to
885        the use of ".".
887    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
888        complete match instead of a partial match. This bug was dependent on both
889        the PCRE_UTF8 and PCRE_DOTALL options being set.
891    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
892        starting byte set, because \b was not being ignored.
895    Version 8.12 15-Jan-2011
896    ------------------------
898    1.  Fixed some typos in the markup of the man pages, and wrote a script that
899        checks for such things as part of the documentation building process.
901    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
902        --match-limit and --recursion-limit options (added for 8.11). In
903        particular, this made one of the standard tests fail. (The integer value
904        went into the wrong half of a long int.)
906    3.  If the --colour option was given to pcregrep with -v (invert match), it
907        did strange things, either producing crazy output, or crashing. It should,
908        of course, ignore a request for colour when reporting lines that do not
909        match.
911    4.  Another pcregrep bug caused similar problems if --colour was specified with
912        -M (multiline) and the pattern match finished with a line ending.
914    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
915        matched in multiline mode, the following line was shown as part of the
916        match. This seems wrong, so I have changed it.
918    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
919        the check for further matches in the same line (so they could be coloured)
920        to overrun the end of the current line. If another match was found, it was
921        incorrectly shown (and then shown again when found in the next line).
923    7.  If pcregrep was compiled under Windows, there was a reference to the
924        function pcregrep_exit() before it was defined. I am assuming this was
925        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
926        reported by a user. I've moved the definition above the reference.
929    Version 8.11 10-Dec-2010
930    ------------------------
932    1.  (*THEN) was not working properly if there were untried alternatives prior
933        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
934        backtracked to try for "b" instead of moving to the next alternative branch
935        at the same level (in this case, to look for "c"). The Perl documentation
936        is clear that when (*THEN) is backtracked onto, it goes to the "next
937        alternative in the innermost enclosing group".
939    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
940        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
941        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
942        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
943        (*THEN).
945    3.  If \s appeared in a character class, it removed the VT character from
946        the class, even if it had been included by some previous item, for example
947        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
948        of \s, but is part of the POSIX "space" class.)
950    4.  A partial match never returns an empty string (because you can always
951        match an empty string at the end of the subject); however the checking for
952        an empty string was starting at the "start of match" point. This has been
953        changed to the "earliest inspected character" point, because the returned
954        data for a partial match starts at this character. This means that, for
955        example, /(?<=abc)def/ gives a partial match for the subject "abc"
956        (previously it gave "no match").
958    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
959        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
960        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
961        has an implication that the given string is incomplete (because a partial
962        match is preferred over a full match). For this reason, these items now
963        give a partial match in this situation. [Aside: previously, the one case
964        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
965        match rather than a full match, which was wrong by the old rules, but is
966        now correct.]
968    6.  There was a bug in the handling of #-introduced comments, recognized when
969        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
970        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
971        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
972        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
973        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
974        places in pcre_compile().
976    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
977        comments when looking ahead for named forward references to subpatterns,
978        the only newline sequence it recognized was NL. It now handles newlines
979        according to the set newline convention.
981    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
982        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
983        cater for a lack of strerror(). These oversights have been fixed.
985    9.  Added --match-limit and --recursion-limit to pcregrep.
987    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
989    11. When the -o option was used, pcregrep was setting a return code of 1, even
990        when matches were found, and --line-buffered was not being honoured.
992    12. Added an optional parentheses number to the -o and --only-matching options
993        of pcregrep.
995    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
996        can match an empty string. The code to do it in pcretest and pcredemo
997        needed fixing:
999        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1000            only one byte after an empty string match just before CRLF (this case
1001            just got forgotten; "any" and "anycrlf" were OK).
1003        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1004            mode when an empty string match preceded an ASCII character followed by
1005            a non-ASCII character. (The code for advancing by one character rather
1006            than one byte was nonsense.)
1008        (c) The pcredemo.c sample program did not have any code at all to handle
1009            the cases when CRLF is a valid newline sequence.
1011    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1012        as a starting offset was within the subject string. There is now a new
1013        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1014        negative or greater than the length of the string. In order to test this,
1015        pcretest is extended to allow the setting of negative starting offsets.
1017    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1018        starting offset points to the beginning of a UTF-8 character was
1019        unnecessarily clumsy. I tidied it up.
1021    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1022        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1024    17. Nobody had reported that the --include_dir option, which was added in
1025        release 7.7 should have been called --include-dir (hyphen, not underscore)
1026        for compatibility with GNU grep. I have changed it to --include-dir, but
1027        left --include_dir as an undocumented synonym, and the same for
1028        --exclude-dir, though that is not available in GNU grep, at least as of
1029        release 2.5.4.
1031    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1032        characters from a string of bytes) have been redefined so as not to use
1033        loops, in order to improve performance in some environments. At the same
1034        time, I abstracted some of the common code into auxiliary macros to save
1035        repetition (this should not affect the compiled code).
1037    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1038        compile-time error is now given if \c is not followed by an ASCII
1039        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1040        different, and any byte value is allowed.)
1042    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1043        START_OPTIMIZE option, which is now allowed at compile time - but just
1044        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1045        to pcregrep and other applications that have no direct access to PCRE
1046        options. The new /Y option in pcretest sets this option when calling
1047        pcre_compile().
1049    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1050        back references. Groups containing recursive back references were forced to
1051        be atomic by that change, but in the case of named groups, the amount of
1052        memory required was incorrectly computed, leading to "Failed: internal
1053        error: code overflow". This has been fixed.
1055    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1056        pcretest.c, to avoid build problems in some Borland environments.
1059    Version 8.10 25-Jun-2010
1060    ------------------------
1062    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1063        THEN.
1065    2.  (*ACCEPT) was not working when inside an atomic group.
1067    3.  Inside a character class, \B is treated as a literal by default, but
1068        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1069        causes the error). The code is unchanged, but I tidied the documentation.
1071    4.  Inside a character class, PCRE always treated \R and \X as literals,
1072        whereas Perl faults them if its -w option is set. I have changed PCRE so
1073        that it faults them when PCRE_EXTRA is set.
1075    5.  Added support for \N, which always matches any character other than
1076        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1078    6.  When compiling pcregrep with newer versions of gcc which may have
1079        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1080        declared with attribute warn_unused_result" were given. Just casting the
1081        result to (void) does not stop the warnings; a more elaborate fudge is
1082        needed. I've used a macro to implement this.
1084    7.  Minor change to pcretest.c to avoid a compiler warning.
1086    8.  Added four artifical Unicode properties to help with an option to make
1087        \s etc use properties (see next item). The new properties are: Xan
1088        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1090    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1091        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1092        this option. Modified pcretest to add /W to test this facility. Added
1093        REG_UCP to make it available via the POSIX interface.
1095    10. Added --line-buffered to pcregrep.
1097    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1098        studied, and the match started with a letter with a code point greater than
1099        127 whose first byte was different to the first byte of the other case of
1100        the letter, the other case of this starting letter was not recognized
1101        (#976).
1103    12. If a pattern that was studied started with a repeated Unicode property
1104        test, for example, \p{Nd}+, there was the theoretical possibility of
1105        setting up an incorrect bitmap of starting bytes, but fortunately it could
1106        not have actually happened in practice until change 8 above was made (it
1107        added property types that matched character-matching opcodes).
1109    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1110        possible starting bytes for non-anchored patterns.
1112    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1113        \R, and also a number of cases that involve Unicode properties, both
1114        explicit and implicit when PCRE_UCP is set.
1116    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1117        input, it could crash or give wrong results if characters with values
1118        greater than 0xc0 were present in the subject string. (Detail: it assumed
1119        UTF-8 input when processing these items.)
1121    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1122        size_t is 64-bit (#991).
1124    17. Added a check for running out of memory when PCRE is compiled with
1125        --disable-stack-for-recursion (#990).
1127    18. If the last data line in a file for pcretest does not have a newline on
1128        the end, a newline was missing in the output.
1130    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1131        less than 128) in its various bitmaps. However, there is a facility for
1132        generating tables according to the current locale when PCRE is compiled. It
1133        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1134        characters, are recognized by isspace() and therefore were getting set in
1135        these tables, and indeed these tables seem to approximate to ISO 8859. This
1136        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1137        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1138        which of course cannot start UTF-8 characters. I have changed the code so
1139        that only real ASCII characters (less than 128) and the correct starting
1140        bytes for UTF-8 encodings are set for characters greater than 127 when in
1141        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1142        altogether.)
1144    20. Added the /T option to pcretest so as to be able to run tests with non-
1145        standard character tables, thus making it possible to include the tests
1146        used for 19 above in the standard set of tests.
1148    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1149        reference to a subpattern the other side of a comment that contains an
1150        opening parenthesis caused either an internal compiling error, or a
1151        reference to the wrong subpattern.
1154    Version 8.02 19-Mar-2010
1155    ------------------------
1157    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1159    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1160        configured.
1162    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1163        original author of that file, following a query about its status.
1165    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1166        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1168    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1169        quantifier applied to a forward-referencing subroutine call, could compile
1170        incorrect code or give the error "internal error: previously-checked
1171        referenced subpattern not found".
1173    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1174        variables to point to external functions. For these systems, therefore,
1175        pcre_malloc etc. are now initialized to local functions that call the
1176        relevant global functions.
1178    7.  There were two entries missing in the vectors called coptable and poptable
1179        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1180        I've fixed the data, and added a kludgy way of testing at compile time that
1181        the lengths are correct (equal to the number of opcodes).
1183    8.  Following on from 7, I added a similar kludge to check the length of the
1184        eint vector in pcreposix.c.
1186    9.  Error texts for pcre_compile() are held as one long string to avoid too
1187        much relocation at load time. To find a text, the string is searched,
1188        counting zeros. There was no check for running off the end of the string,
1189        which could happen if a new error number was added without updating the
1190        string.
1192    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1194    11. \K was not working if it appeared in an atomic group or in a group that
1195        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1196        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1197        the assertion is positive, but not if it is negative.
1199    12. Change 11 fortuitously reduced the size of the stack frame used in the
1200        "match()" function of pcre_exec.c by one pointer. Forthcoming
1201        implementation of support for (*MARK) will need an extra pointer on the
1202        stack; I have reserved it now, so that the stack frame size does not
1203        decrease.
1205    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1206        item in branch that calls a recursion is a subroutine call - as in the
1207        second branch in the above example - was incorrectly given the compile-
1208        time error "recursive call could loop indefinitely" because pcre_compile()
1209        was not correctly checking the subroutine for matching a non-empty string.
1211    14. The checks for overrunning compiling workspace could trigger after an
1212        overrun had occurred. This is a "should never occur" error, but it can be
1213        triggered by pathological patterns such as hundreds of nested parentheses.
1214        The checks now trigger 100 bytes before the end of the workspace.
1216    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1219    Version 8.01 19-Jan-2010
1220    ------------------------
1222    1.  If a pattern contained a conditional subpattern with only one branch (in
1223        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1224        computed the wrong minimum data length (which is of course zero for such
1225        subpatterns). This could cause incorrect "no match" results.
1227    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1228        the pattern is reset in the first branch, pcre_compile() failed with
1229        "internal error: code overflow at offset...". This happened only when
1230        the reset was to the original external option setting. (An optimization
1231        abstracts leading options settings into an external setting, which was the
1232        cause of this.)
1234    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1235        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1236        assertion pattern did not match (meaning that the assertion was true), it
1237        was incorrectly treated as false if the SKIP had been reached during the
1238        matching. This also applied to assertions used as conditions.
1240    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1241        assertion subpattern, including such a pattern used as a condition,
1242        unpredictable results occurred, instead of the error return
1245    5.  The C++ GlobalReplace function was not working like Perl for the special
1246        situation when an empty string is matched. It now does the fancy magic
1247        stuff that is necessary.
1249    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1250        removed. (These were left over from very, very early versions of PCRE.)
1252    7.  Some cosmetic changes to the code to make life easier when compiling it
1253        as part of something else:
1255        (a) Change DEBUG to PCRE_DEBUG.
1257        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1258            called "current" as "current_branch", to prevent a collision with the
1259            Linux macro when compiled as a kernel module.
1261        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1262            prevent a collision with the Linux macro when compiled as a kernel
1263            module.
1265    8.  In pcre_compile() there are some checks for integer overflows that used to
1266        cast potentially large values to (double). This has been changed to that
1267        when building, a check for int64_t is made, and if it is found, it is used
1268        instead, thus avoiding the use of floating point arithmetic. (There is no
1269        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1270        double.
1272    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1273        2005 (difference between two addresses compared to an unsigned value).
1275    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1276        custom one, because of the following reported problem in Windows:
1278          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1279              under Win32.
1280          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1281              therefore missing the function definition.
1282          - The compiler thus generates a "C" signature for the test function.
1283          - The linker fails to find the "C" function.
1284          - PCRE fails to configure if asked to do so against libbz2.
1286    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1287        messages were output:
1289          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1290          rerunning libtoolize, to keep the correct libtool macros in-tree.
1291          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1293        I have done both of these things.
1295    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1296        most of the time, it *can* run out if it is given a pattern that contains a
1297        runaway infinite recursion. I updated the discussion in the pcrestack man
1298        page.
1300    13. Now that we have gone to the x.xx style of version numbers, the minor
1301        version may start with zero. Using 08 or 09 is a bad idea because users
1302        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1303        interpreted as invalid octal numbers. I've updated the previous comment in
1304        configure.ac, and also added a check that gives an error if 08 or 09 are
1305        used.
1307    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1308        causing partial matching to fail when the end of the subject matched \W
1309        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1311    15. There were some discrepancies between the declarations in pcre_internal.h
1312        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1313        their definitions. The declarations used "const uschar *" and the
1314        definitions used USPTR. Even though USPTR is normally defined as "const
1315        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1316        reported that: "This difference in casting confuses some C++ compilers, for
1317        example, SunCC recognizes above declarations as different functions and
1318        generates broken code for hbpcre." I have changed the declarations to use
1319        USPTR.
1321    16. GNU libtool is named differently on some systems. The autogen.sh script now
1322        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1323        (FreeBSD).
1325    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1326        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1327        comment: "Figure out how to create a longlong from a string: strtoll and
1328        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1329        instance, but it only takes 2 args instead of 3!"
1331    18. A subtle bug concerned with back references has been fixed by a change of
1332        specification, with a corresponding code fix. A pattern such as
1333        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1334        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1335        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1336        same bug. Such groups have to be quantified to be useful, or contained
1337        inside another quantified group. (If there's no repetition, the reference
1338        can never match.) The problem arises because, having left the group and
1339        moved on to the rest of the pattern, a later failure that backtracks into
1340        the group uses the captured value from the final iteration of the group
1341        rather than the correct earlier one. I have fixed this in PCRE by forcing
1342        any group that contains a reference to itself to be an atomic group; that
1343        is, there cannot be any backtracking into it once it has completed. This is
1344        similar to recursive and subroutine calls.
1347    Version 8.00 19-Oct-09
1348    ----------------------
1350    1.  The table for translating pcre_compile() error codes into POSIX error codes
1351        was out-of-date, and there was no check on the pcre_compile() error code
1352        being within the table. This could lead to an OK return being given in
1353        error.
1355    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1356        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1357        in a Windows environment.
1359    3.  The pcregrep --count option prints the count for each file even when it is
1360        zero, as does GNU grep. However, pcregrep was also printing all files when
1361        --files-with-matches was added. Now, when both options are given, it prints
1362        counts only for those files that have at least one match. (GNU grep just
1363        prints the file name in this circumstance, but including the count seems
1364        more useful - otherwise, why use --count?) Also ensured that the
1365        combination -clh just lists non-zero counts, with no names.
1367    4.  The long form of the pcregrep -F option was incorrectly implemented as
1368        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1369        but it seems right to fix it, and I didn't think it was worth preserving
1370        the old behaviour.
1372    5.  The command line items --regex=pattern and --regexp=pattern were not
1373        recognized by pcregrep, which required --regex pattern or --regexp pattern
1374        (with a space rather than an '='). The man page documented the '=' forms,
1375        which are compatible with GNU grep; these now work.
1377    6.  No libpcreposix.pc file was created for pkg-config; there was just
1378        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1380    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1381        when UCP support is not needed, by modifying the Python script that
1382        generates it from Unicode data files. This should not matter if the module
1383        is correctly used as a library, but I received one complaint about 50K of
1384        unwanted data. My guess is that the person linked everything into his
1385        program rather than using a library. Anyway, it does no harm.
1387    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1388        was a minimum greater than 1 for a wide character in a possessive
1389        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1390        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1391        character. Chaos in the form of incorrect output or a compiling loop could
1392        result.
1394    9.  The restrictions on what a pattern can contain when partial matching is
1395        requested for pcre_exec() have been removed. All patterns can now be
1396        partially matched by this function. In addition, if there are at least two
1397        slots in the offset vector, the offset of the earliest inspected character
1398        for the match and the offset of the end of the subject are set in them when
1399        PCRE_ERROR_PARTIAL is returned.
1401    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1402        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1403        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1404        and may be more useful for multi-segment matching.
1406    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1407        used to be given if ever the end of the subject was reached; now it is
1408        given only if matching could not proceed because another character was
1409        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1410        string "Z", which now yields "no match" instead of "partial match". In the
1411        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1412        final character ended with (*FAIL).
1414    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1415        if the pattern had a "must contain" character that was already found in the
1416        earlier partial match, unless partial matching was again requested. For
1417        example, with the pattern /dog.(body)?/, the "must contain" character is
1418        "g". If the first part-match was for the string "dog", restarting with
1419        "sbody" failed. This bug has been fixed.
1421    13. The string returned by pcre_dfa_exec() after a partial match has been
1422        changed so that it starts at the first inspected character rather than the
1423        first character of the match. This makes a difference only if the pattern
1424        starts with a lookbehind assertion or \b or \B (\K is not supported by
1425        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1426        matching functions compatible, and I think it's the right thing to do.
1428    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1429        so that the demonstration program is easily available in environments where
1430        PCRE has not been installed from source.
1432    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1433        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1434        library.
1436    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1437        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1438        is not the first non-POSIX option to be added. Clearly some people find
1439        these options useful.
1441    17. If a caller to the POSIX matching function regexec() passes a non-zero
1442        value for nmatch with a NULL value for pmatch, the value of
1443        nmatch is forced to zero.
1445    18. RunGrepTest did not have a test for the availability of the -u option of
1446        the diff command, as RunTest does. It now checks in the same way as
1447        RunTest, and also checks for the -b option.
1449    19. If an odd number of negated classes containing just a single character
1450        interposed, within parentheses, between a forward reference to a named
1451        subpattern and the definition of the subpattern, compilation crashed with
1452        an internal error, complaining that it could not find the referenced
1453        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1454        [The bug was that it was starting one character too far in when skipping
1455        over the character class, thus treating the ] as data rather than
1456        terminating the class. This meant it could skip too much.]
1458    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1459        /g option in pcretest when the pattern contains \K, which makes it possible
1460        to have an empty string match not at the start, even when the pattern is
1461        anchored. Updated pcretest and pcredemo to use this option.
1463    21. If the maximum number of capturing subpatterns in a recursion was greater
1464        than the maximum at the outer level, the higher number was returned, but
1465        with unset values at the outer level. The correct (outer level) value is
1466        now given.
1468    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1469        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1470        make it do so. The string so far is captured, making this feature
1471        compatible with Perl.
1473    23. The tests have been re-organized, adding tests 11 and 12, to make it
1474        possible to check the Perl 5.10 features against Perl 5.10.
1476    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1477        pattern matches a fixed length string. PCRE did not allow this; now it
1478        does. Neither allows recursion.
1480    25. I finally figured out how to implement a request to provide the minimum
1481        length of subject string that was needed in order to match a given pattern.
1482        (It was back references and recursion that I had previously got hung up
1483        on.) This code has now been added to pcre_study(); it finds a lower bound
1484        to the length of subject needed. It is not necessarily the greatest lower
1485        bound, but using it to avoid searching strings that are too short does give
1486        some useful speed-ups. The value is available to calling programs via
1487        pcre_fullinfo().
1489    26. While implementing 25, I discovered to my embarrassment that pcretest had
1490        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1491        study optimizations had never been tested with that matching function.
1492        Oops. What is worse, even when it was passed study data, there was a bug in
1493        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1494        were also very few tests of studied patterns with pcre_dfa_exec().
1496    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1497        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1498        on the other side of the coin, they are no longer allowed to have different
1499        names, because these cannot be distinguished in PCRE, and this has caused
1500        confusion. (This is a difference from Perl.)
1502    28. When duplicate subpattern names are present (necessarily with different
1503        numbers, as required by 27 above), and a test is made by name in a
1504        conditional pattern, either for a subpattern having been matched, or for
1505        recursion in such a pattern, all the associated numbered subpatterns are
1506        tested, and the overall condition is true if the condition is true for any
1507        one of them. This is the way Perl works, and is also more like the way
1508        testing by number works.
1511    Version 7.9 11-Apr-09
1512    ---------------------
1514    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1515        (pcretest), all targets were linked against these libraries. This included
1516        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1517        libraries. This caused unwanted dependencies to be created. This problem
1518        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1519        pcretest is linked with readline.
1521    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1522        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1523        moved outside it again, because FALSE and TRUE are already defined in AIX,
1524        but BOOL is not.
1526    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1527        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1529    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1530        hyphens) following file names and line numbers when outputting matching
1531        lines. This is not true; no spaces are inserted. I have also clarified the
1532        wording for the --colour (or --color) option.
1534    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1535        was not coloured; this is different to GNU grep, so I have changed it to be
1536        the same.
1538    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1539        each matching line was coloured. Now it goes on to look for further matches
1540        of any of the test patterns, which is the same behaviour as GNU grep.
1542    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1543        doesn't make sense to accept an empty string match in pcregrep, so I have
1544        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1545        seems to be how GNU grep behaves.
1547    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1548        start or after a newline", because the conditional assertion was not being
1549        correctly handled. The rule now is that both the assertion and what follows
1550        in the first alternative must satisfy the test.
1552    9.  If auto-callout was enabled in a pattern with a conditional group whose
1553        condition was an assertion, PCRE could crash during matching, both with
1554        pcre_exec() and pcre_dfa_exec().
1556    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1557        used for matching.
1559    11. Unicode property support in character classes was not working for
1560        characters (bytes) greater than 127 when not in UTF-8 mode.
1562    12. Added the -M command line option to pcretest.
1564    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1566    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1568    16. Added comments and documentation about mis-use of no_arg in the C++
1569        wrapper.
1571    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1572        from Martin Jerabek that uses macro names for all relevant character and
1573        string constants.
1575    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1576        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1577        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1578        these, but not everybody uses configure.
1580    19. A conditional group that had only one branch was not being correctly
1581        recognized as an item that could match an empty string. This meant that an
1582        enclosing group might also not be so recognized, causing infinite looping
1583        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1584        with the subject "ab", where knowledge that the repeated group can match
1585        nothing is needed in order to break the loop.
1587    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1588        exec(), but without supplying a callout function, matching went wrong.
1590    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1591        leak if the size of the offset vector was greater than 30. When the vector
1592        is smaller, the saved offsets during recursion go onto a local stack
1593        vector, but for larger vectors malloc() is used. It was failing to free
1594        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1595        error, in fact).
1597    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1598        heapframe that is used only when UTF-8 support is enabled. This caused no
1599        problem, but was untidy.
1601    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1602        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1603        included within another project.
1605    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1606        slightly modified by me:
1608          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1609              not building pcregrep.
1611          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1612              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1614    25. Forward references, both numeric and by name, in patterns that made use of
1615        duplicate group numbers, could behave incorrectly or give incorrect errors,
1616        because when scanning forward to find the reference group, PCRE was not
1617        taking into account the duplicate group numbers. A pattern such as
1618        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1620    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1621        the feature of a custom pointer more persuasive (as requested by a user).
1623    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1624        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1625        pre-defined.
1627    28. Added support for (*UTF8) at the start of a pattern.
1629    29. Arrange for flags added by the "release type" setting in CMake to be shown
1630        in the configuration summary.
1633    Version 7.8 05-Sep-08
1634    ---------------------
1636    1.  Replaced UCP searching code with optimized version as implemented for Ad
1637        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1638        stage table and inline lookup instead of a function, giving speed ups of 2
1639        to 5 times on some simple patterns that I tested. Permission was given to
1640        distribute the MultiStage2.py script that generates the tables (it's not in
1641        the tarball, but is in the Subversion repository).
1643    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1644        scripts.
1646    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1647        a group with a zero qualifier. The result of the study could be incorrect,
1648        or the function might crash, depending on the pattern.
1650    4.  Caseless matching was not working for non-ASCII characters in back
1651        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1652        It now works when Unicode Property Support is available.
1654    5.  In pcretest, an escape such as \x{de} in the data was always generating
1655        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1656        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1657        truncation.
1659    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1661    7.  Added two (int) casts to pcregrep when printing the difference of two
1662        pointers, in case they are 64-bit values.
1664    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1665        test 2 if it fails.
1667    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1668        and a #define of that name to empty if it is not externally set. This is to
1669        allow users of MSVC to set it if necessary.
1671    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1672        the convenience functions in the pcre_get.c source file.
1674    11. An option change at the start of a pattern that had top-level alternatives
1675        could cause overwriting and/or a crash. This command provoked a crash in
1676        some environments:
1678          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1680        This potential security problem was recorded as CVE-2008-2371.
1682    12. For a pattern where the match had to start at the beginning or immediately
1683        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1684        pcre_dfa_exec() could read past the end of the passed subject if there was
1685        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1686        pcretest so that it places the subject at the end of its malloc-ed buffer.
1688    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1689        exec() might read past the end of the data buffer in UTF-8 mode.
1691    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1692        the data contained the byte 0x85 as part of a UTF-8 character within its
1693        first line. This applied both to normal and DFA matching.
1695    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1696        /^[^d]*?$/8 failed to match "abc".
1698    16. Added a missing copyright notice to pcrecpp_internal.h.
1700    17. Make it more clear in the documentation that values returned from
1701        pcre_exec() in ovector are byte offsets, not character counts.
1703    18. Tidied a few places to stop certain compilers from issuing warnings.
1705    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1706        supplied by Stefan Weber. I made a further small update for 7.8 because
1707        there is a change of source arrangements: the pcre_searchfuncs.c module is
1708        replaced by pcre_ucd.c.
1711    Version 7.7 07-May-08
1712    ---------------------
1714    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1715        a string to a long long, pretend we don't even have a long long." This is
1716        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1718    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1719        pre-7.6 versions, which defined a global no_arg variable instead of putting
1720        it in the RE class. (See also #8 below.)
1722    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1723        Lopes.
1725    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1727        (1) The include/exclude patterns were being applied to the whole pathnames
1728            of files, instead of just to the final components.
1730        (2) If there was more than one level of directory, the subdirectories were
1731            skipped unless they satisfied the include/exclude conditions. This is
1732            inconsistent with GNU grep (and could even be seen as contrary to the
1733            pcregrep specification - which I improved to make it absolutely clear).
1734            The action now is always to scan all levels of directory, and just
1735            apply the include/exclude patterns to regular files.
1737    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1738        --exclude_dir in the tests to avoid scanning .svn directories.
1740    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1741        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1742        doesn't support NULs in patterns.
1744    7.  Added some missing "const"s to declarations of static tables in
1745        pcre_compile.c and pcre_dfa_exec.c.
1747    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1748        caused by fix #2  above. (Subsequently also a second patch to fix the
1749        first patch. And a third patch - this was a messy problem.)
1751    9.  Applied Craig's patch to remove the use of push_back().
1753    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1754        matching function regexec().
1756    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1757        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1758        references. PCRE supports relative numbers with this syntax (I don't think
1759        Oniguruma does).
1761    12. Previously, a group with a zero repeat such as (...){0} was completely
1762        omitted from the compiled regex. However, this means that if the group
1763        was called as a subroutine from elsewhere in the pattern, things went wrong
1764        (an internal error was given). Such groups are now left in the compiled
1765        pattern, with a new opcode that causes them to be skipped at execution
1766        time.
1768    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1769        to the way PCRE behaves:
1771        (a) A lone ] character is dis-allowed (Perl treats it as data).
1773        (b) A back reference to an unmatched subpattern matches an empty string
1774            (Perl fails the current match path).
1776        (c) A data ] in a character class must be notated as \] because if the
1777            first data character in a class is ], it defines an empty class. (In
1778            Perl it is not possible to have an empty class.) The empty class []
1779            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1780            The negative empty class [^] matches any one character, independently
1781            of the DOTALL setting.
1783    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1784        non-existent subpattern following a character class starting with ']' and
1785        containing () gave an internal compiling error instead of "reference to
1786        non-existent subpattern". Fortunately, when the pattern did exist, the
1787        compiled code was correct. (When scanning forwards to check for the
1788        existencd of the subpattern, it was treating the data ']' as terminating
1789        the class, so got the count wrong. When actually compiling, the reference
1790        was subsequently set up correctly.)
1792    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1793        it was being rejected as not supported by pcre_dfa_exec(), even though
1794        other assertions are supported. I have made pcre_dfa_exec() support
1795        (*FAIL).
1797    16. The implementation of 13c above involved the invention of a new opcode,
1798        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1799        cannot be changed at match time, I realized I could make a small
1800        improvement to matching performance by compiling OP_ALLANY instead of
1801        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1802        on the OP_ANY path.
1804    17. Compiling pcretest on Windows with readline support failed without the
1805        following two fixes: (1) Make the unistd.h include conditional on
1806        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1808    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1809        ncurses library to be included for pcretest when ReadLine support is
1810        requested, but also to allow for it to be overridden. This patch came from
1811        Daniel Bergström.
1813    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1814        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1815        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1816        spotting this.
1819    Version 7.6 28-Jan-08
1820    ---------------------
1822    1.  A character class containing a very large number of characters with
1823        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1824        overflow.
1826    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1827        HAVE_LONG_LONG is not defined.
1829    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1830        bring them up to date and include new features. This patch includes:
1832        - Fixed PH's badly added libz and libbz2 support.
1833        - Fixed a problem with static linking.
1834        - Added pcredemo. [But later removed - see 7 below.]
1835        - Fixed dftables problem and added an option.
1836        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1837            HAVE_LONG_LONG.
1838        - Added readline support for pcretest.
1839        - Added an listing of the option settings after cmake has run.
1841    4.  A user submitted a patch to Makefile that makes it easy to create
1842        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1843        Makefile.am that cause it to include this special target, without
1844        affecting anything else. Note that the same mingw target plus all
1845        the other distribution libraries and programs are now supported
1846        when configuring with CMake (see 6 below) instead of with
1847        Configure/Make.
1849    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1850        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1851        exported in the Windows port". It has not yet been confirmed that the patch
1852        solves the problem, but it does no harm.
1854    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1855        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1856        with CMake, and also correct the comment about stack recursion.
1858    7.  Remove the automatic building of pcredemo from the ./configure system and
1859        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1860        of a program that users should build themselves after PCRE is installed, so
1861        building it automatically is not really right. What is more, it gave
1862        trouble in some build environments.
1864    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1867    Version 7.5 10-Jan-08
1868    ---------------------
1870    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1871        values in parens when parsing an RE using the C++ wrapper."
1873    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1874        Characters greater than 255 were excluded from the class instead of being
1875        included.
1877    3.  The same bug as (2) above applied to negated POSIX classes such as
1878        [:^space:].
1880    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1881        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1882        I have changed it.
1884    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1885        first named subpattern) and a construct such as (?&a) would reference the
1886        first named subpattern whose name started with "a" (in other words, the
1887        length check was missing). Both these problems are fixed. "Subpattern name
1888        expected" is now given for (?&) (a zero-length name), and this patch also
1889        makes it give the same error for \k'' (previously it complained that that
1890        was a reference to a non-existent subpattern).
1892    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1893        this is right because (?- can be followed by option settings as well as by
1894        digits. I have, however, made the messages clearer.
1896    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1897        than the number used in the conditional) now cause a compile-time error.
1898        This is actually not compatible with Perl, which accepts such patterns, but
1899        treats the conditional as always being FALSE (as PCRE used to), but it
1900        seems to me that giving a diagnostic is better.
1902    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1903        and messages.
1905    9.  Fix two occurrences of "backslash" in comments that should have been
1906        "backspace".
1908    10. Remove two redundant lines of code that can never be obeyed (their function
1909        was moved elsewhere).
1911    11. The program that makes PCRE's Unicode character property table had a bug
1912        which caused it to generate incorrect table entries for sequences of
1913        characters that have the same character type, but are in different scripts.
1914        It amalgamated them into a single range, with the script of the first of
1915        them. In other words, some characters were in the wrong script. There were
1916        thirteen such cases, affecting characters in the following ranges:
1918          U+002b0 - U+002c1
1919          U+0060c - U+0060d
1920          U+0061e - U+00612
1921          U+0064b - U+0065e
1922          U+0074d - U+0076d
1923          U+01800 - U+01805
1924          U+01d00 - U+01d77
1925          U+01d9b - U+01dbf
1926          U+0200b - U+0200f
1927          U+030fc - U+030fe
1928          U+03260 - U+0327f
1929          U+0fb46 - U+0fbb1
1930          U+10450 - U+1049d
1932    12. The -o option (show only the matching part of a line) for pcregrep was not
1933        compatible with GNU grep in that, if there was more than one match in a
1934        line, it showed only the first of them. It now behaves in the same way as
1935        GNU grep.
1937    13. If the -o and -v options were combined for pcregrep, it printed a blank
1938        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1939        does the same. The return code can be used to tell if there were any
1940        non-matching lines.
1942    14. Added --file-offsets and --line-offsets to pcregrep.
1944    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1945        infinitely looping recursion. The bug was that positive lookaheads were not
1946        being skipped when checking for a possible empty match (negative lookaheads
1947        and both kinds of lookbehind were skipped).
1949    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1950        inclusion of <windows.h> to before rather than after the definition of
1951        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1953    17. Specifying a possessive quantifier with a specific limit for a Unicode
1954        character property caused pcre_compile() to compile bad code, which led at
1955        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1956        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1957        caused the error; without that there was no problem.
1959    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1961    19. Added --enable-pcretest-libreadline.
1963    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1964        RE::GlobalReplace(). As a result, the number of replacements returned was
1965        double what it should be. I removed one of the increments, but Craig sent a
1966        later patch that removed the other one (the right fix) and added unit tests
1967        that check the return values (which was not done before).
1969    21. Several CMake things:
1971        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1972            the names libpcre and libpcreposix, not just pcre and pcreposix.
1974        (2) The above change means that pcretest and pcregrep are now correctly
1975            linked with the newly-built libraries, not previously installed ones.
1979    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1980        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1981        UTF-8 newline character). The key issue is that the pattern starts .*;
1982        this means that the match must be either at the beginning, or after a
1983        newline. The bug was in the code for advancing after a failed match and
1984        checking that the new position followed a newline. It was not taking
1985        account of UTF-8 characters correctly.
1987    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1988        character classes. PCRE was not treating the sequence [:...:] as a
1989        character class unless the ... were all letters. Perl, however, seems to
1990        allow any characters between [: and :], though of course it rejects as
1991        unknown any "names" that contain non-letters, because all the known class
1992        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1993        for example, whereas PCRE did not - it did not recognize a POSIX character
1994        class. This seemed a bit dangerous, so the code has been changed to be
1995        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1996        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1997        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1998        Perl does, and where it didn't before.
2000    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2001        Windows environments %n is disabled by default.
2004    Version 7.4 21-Sep-07
2005    ---------------------
2007    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
2008        means that a class such as [\s] counted as "explicit reference to CR or
2009        LF". That isn't really right - the whole point of the change was to try to
2010        help when there was an actual mention of one of the two characters. So now
2011        the change happens only if \r or \n (or a literal CR or LF) character is
2012        encountered.
2014    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
2015        of both had grown to the point where there were only 3 bits left.
2016        Fortunately, there was spare space in the data structure, and so I have
2017        moved the internal flags into a new 16-bit field to free up more option
2018        bits.
2020    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2021        but did not set the internal JCHANGED flag - either of these is enough to
2022        control the way the "get" function works - but the PCRE_INFO_JCHANGED
2023        facility is supposed to tell if (?J) was ever used, so now (?J) at the
2024        start sets both bits.
2026    4.  Added options (at build time, compile time, exec time) to change \R from
2027        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2029    5.  doc/pcresyntax.html was missing from the distribution.
2031    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2032        compatibility, even though it is no longer used.
2034    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2035        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2036        windows.h file is present (where different names are used). [This was
2037        reversed later after testing - see 16 below.]
2039    8.  Changed all #include <config.h> to #include "config.h". There were also
2040        some further <pcre.h> cases that I changed to "pcre.h".
2042    9.  When pcregrep was used with the --colour option, it missed the line ending
2043        sequence off the lines that it output.
2045    10. It was pointed out to me that arrays of string pointers cause lots of
2046        relocations when a shared library is dynamically loaded. A technique of
2047        using a single long string with a table of offsets can drastically reduce
2048        these. I have refactored PCRE in four places to do this. The result is
2049        dramatic:
2051          Originally:                          290
2052          After changing UCP table:            187
2053          After changing error message table:   43
2054          After changing table of "verbs"       36
2055          After changing table of Posix names   22
2057        Thanks to the folks working on Gregex for glib for this insight.
2059    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2060        unicode-properties was also set.
2062    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2064    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2065        checked only for CRLF.
2067    14. Added casts to pcretest.c to avoid compiler warnings.
2069    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2071    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2072        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2073        entirely. This removes changes made in 7 above.
2075    17. The CMake files have been updated, and there is now more information about
2076        building with CMake in the NON-UNIX-USE document.
2079    Version 7.3 28-Aug-07
2080  ---------------------  ---------------------
2082   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 143  Version 7.3 17-Aug-07 Line 2218  Version 7.3 17-Aug-07
2218  24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte  24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2219      characters were involved (for example /\S{2}/8g with "A\x{a3}BC").      characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2221    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2223    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2224        character were causing crashes (broken optimization).
2226    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2227        \p or \P) caused a compile-time loop.
2229    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2230        break. For example, the unstudied pattern [\r\n]A does not match the string
2231        "\r\nA" because change 7.0/46 below moves the current point on by two
2232        characters after failing to match at the start. However, the pattern \nA
2233        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2234        the same is true. There doesn't seem any very clean way out of this, but
2235        what I have chosen to do makes the common cases work: PCRE now takes note
2236        of whether there can be an explicit match for \r or \n anywhere in the
2237        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2238        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2239        pattern has explicit CR or LF references.
2241    29. Added (*CR) etc for changing newline setting at start of pattern.
2244  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
2245  ---------------------  ---------------------

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