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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-08  Version 8.34 15-December-2013
5    -----------------------------
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
10    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11        this macro is never tested and has no effect, because the work to support
12        coverage involves only compiling and linking options and special targets in
13        the Makefile. The comment in config.h implied that defining the macro would
14        enable coverage support, which is totally false. There was also support for
15        setting this macro in the CMake files (my fault, I just copied it from
16        configure). SUPPORT_GCOV has now been removed.
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
21    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23        these cases). There was also one in pcretest.c.
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
27    6.  In UTF mode, the code for checking whether a group could match an empty
28        string (which is used for indefinitely repeated groups to allow for
29        breaking an infinite loop) was broken when the group contained a repeated
30        negated single-character class with a character that occupied more than one
31        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32        UTF-8 mode). The effect was undefined: the group might or might not be
33        deemed as matching an empty string, or the program might have crashed.
35    7.  The code for checking whether a group could match an empty string was not
36        recognizing that \h, \H, \v, \V, and \R must match a character.
38    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39        an empty string. If it can, pcretest shows this in its information output.
41    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
42        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43        matched by pcre_exec() without using JIT:
45        (a) If the rest of the pattern did not match after a maximal run of
46            grapheme clusters, the code for backing up to try with fewer of them
47            did not always back up over a full grapheme when characters that do not
48            have the modifier quality were involved, e.g. Hangul syllables.
50        (b) If the match point in a subject started with modifier character, and
51            there was no match, the code could incorrectly back up beyond the match
52            point, and potentially beyond the first character in the subject,
53            leading to a segfault or an incorrect match result.
55    10. A conditional group with an assertion condition could lead to PCRE
56        recording an incorrect first data item for a match if no other first data
57        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
58        first data item, and therefore matched "ca" after "c" instead of at the
59        start.
61    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
62        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
64    12. The source of pcregrep now includes z/OS-specific code so that it can be
65        compiled for z/OS as part of the special z/OS distribution.
67    13. Added the -T and -TM options to pcretest.
69    14. The code in pcre_compile.c for creating the table of named capturing groups
70        has been refactored. Instead of creating the table dynamically during the
71        actual compiling pass, the information is remembered during the pre-compile
72        pass (on the stack unless there are more than 20 named groups, in which
73        case malloc() is used) and the whole table is created before the actual
74        compile happens. This has simplified the code (it is now nearly 150 lines
75        shorter) and prepared the way for better handling of references to groups
76        with duplicate names.
78    15. A back reference to a named subpattern when there is more than one of the
79        same name now checks them in the order in which they appear in the pattern.
80        The first one that is set is used for the reference. Previously only the
81        first one was inspected. This change makes PCRE more compatible with Perl.
83    16. Unicode character properties were updated from Unicode 6.3.0.
85    17. The compile-time code for auto-possessification has been refactored, based
86        on a patch by Zoltan Herczeg. It now happens after instead of during
87        compilation. The code is cleaner, and more cases are handled. The option
88        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
89        options in pcretest are provided to set it. It can also be set by
90        (*NO_AUTO_POSSESS) at the start of a pattern.
92    18. The character VT has been added to the default ("C" locale) set of
93        characters that match \s and are generally treated as white space,
94        following this same change in Perl 5.18. There is now no difference between
95        "Perl space" and "POSIX space". Whether VT is treated as white space in
96        other locales depends on the locale.
98    19. The code for checking named groups as conditions, either for being set or
99        for being recursed, has been refactored (this is related to 14 and 15
100        above). Processing unduplicated named groups should now be as fast at
101        numerical groups, and processing duplicated groups should be faster than
102        before.
104    20. Two patches to the CMake build system, by Alexander Barkov:
106          (1) Replace the "source" command by "." in CMakeLists.txt because
107              "source" is a bash-ism.
109          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
110              without these the CMake build does not work on Solaris.
112    21. Perl has changed its handling of \8 and \9. If there is no previously
113        encountered capturing group of those numbers, they are treated as the
114        literal characters 8 and 9 instead of a binary zero followed by the
115        literals. PCRE now does the same.
117    22. Following Perl, added \o{} to specify codepoints in octal, making it
118        possible to specify values greater than 0777 and also making them
119        unambiguous.
121    23. Perl now gives an error for missing closing braces after \x{... instead of
122        treating the string as literal. PCRE now does the same.
124    24. RunTest used to grumble if an inappropriate test was selected explicitly,
125        but just skip it when running all tests. This make it awkward to run ranges
126        of tests when one of them was inappropriate. Now it just skips any
127        inappropriate tests, as it always did when running all tests.
129    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
130        character types such as \d or \w, too many callouts were inserted, and the
131        data that they returned was rubbish.
133    26. In UCP mode, \s was not matching two of the characters that Perl matches,
134        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
135        were matched by \h. The code has now been refactored so that the lists of
136        the horizontal and vertical whitespace characters used for \h and \v (which
137        are defined only in one place) are now also used for \s.
139    27. Add JIT support for the 64 bit TileGX architecture.
140        Patch by Jiong Wang (Tilera Corporation).
142    28. Possessive quantifiers for classes (both explicit and automatically
143        generated) now use special opcodes instead of wrapping in ONCE brackets.
145    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
146        (because it's meaningless), this was not happening when PCRE_CASELESS was
147        set. Not wrong, but inefficient.
149    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
150        properties for \w, \d, etc) is present in a test regex. Otherwise if the
151        test contains no characters greater than 255, Perl doesn't realise it
152        should be using Unicode semantics.
154    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
155        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
156        does in Unicode mode.
158    32. Added the "forbid" facility to pcretest so that putting tests into the
159        wrong test files can sometimes be quickly detected.
161    33. There is now a limit (default 250) on the depth of nesting of parentheses.
162        This limit is imposed to control the amount of system stack used at compile
163        time. It can be changed at build time by --with-parens-nest-limit=xxx or
164        the equivalent in CMake.
166    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
167        errors. Perl warns for these when in warning mode, but PCRE has no facility
168        for giving warnings.
170    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
171        However, this was not working for (?!) because it is optimized to (*FAIL),
172        for which PCRE does not allow quantifiers. The optimization is now disabled
173        when a quantifier follows (?!). I can't see any use for this, but it makes
174        things uniform.
176    36. Perl no longer allows group names to start with digits, so I have made this
177        change also in PCRE. It simplifies the code a bit.
179    37. In extended mode, Perl ignores spaces before a + that indicates a
180        possessive quantifier. PCRE allowed a space before the quantifier, but not
181        before the possessive +. It now does.
183    38. The use of \K (reset reported match start) within a repeated possessive
184        group such as (a\Kb)*+ was not working.
186    40. Document that the same character tables must be used at compile time and
187        run time, and that the facility to pass tables to pcre_exec() and
188        pcre_dfa_exec() is for use only with saved/restored patterns.
190    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
191        features for Builds with MSVC:
193        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
194           builds). The .rc files can be used to set FileDescription and many other
195           attributes.
197        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
198           This allows higher-level build scripts which want .pdb files to avoid
199           hard-coding the exact files needed."
201    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
202        mean "start of word" and "end of word", respectively, as a transition aid.
204    43. A minimizing repeat of a class containing codepoints greater than 255 in
205        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
206        compiled to use the heap for recursion.
208    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
209        is configured.
212    Version 8.33 28-May-2013
213    ------------------------
215    1.  Added 'U' to some constants that are compared to unsigned integers, to
216        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
217        variables that are added to signed variables, to ensure the result is
218        signed and can be negated.
220    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
221        CMake config files.
223    3.  Revise the creation of config.h.generic so that all boolean macros are
224        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
225        overriding via -D on the command line possible.
227    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
228        to unsigned int is reported to make a quite noticeable speed difference in
229        a specific Windows environment. Testing on Linux did also appear to show
230        some benefit (and it is clearly not harmful). Also fixed the definition of
231        Xop which should be unsigned.
233    5.  Related to (4), changing the definition of the intermediate variable cc
234        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
235        improvements.
237    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
238        unnecessary spaces.
240    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
241        and later.
243    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
245    9.  Optimizing fast_forward_start_bits in JIT.
247    10. Adding support for callouts in JIT, and fixing some issues revealed
248        during this work. Namely:
250        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
252        (b) Minimum length was not checked before the matching is started.
254    11. The value of capture_last that is passed to callouts was incorrect in some
255        cases when there was a capture on one path that was subsequently abandoned
256        after a backtrack. Also, the capture_last value is now reset after a
257        recursion, since all captures are also reset in this case.
259    12. The interpreter no longer returns the "too many substrings" error in the
260        case when an overflowing capture is in a branch that is subsequently
261        abandoned after a backtrack.
263    13. In the pathological case when an offset vector of size 2 is used, pcretest
264        now prints out the matched string after a yield of 0 or 1.
266    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
267        Only supported by the JIT compiler at the moment.
269    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
271    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
272        offset of the starting point of the matching process, provided the offsets
273        vector is large enough.
275    17. The \A escape now records a lookbehind value of 1, though its execution
276        does not actually inspect the previous character. This is to ensure that,
277        in partial multi-segment matching, at least one character from the old
278        segment is retained when a new segment is processed. Otherwise, if there
279        are no lookbehinds in the pattern, \A might match incorrectly at the start
280        of a new segment.
282    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
284    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
285        gives some modest performance improvement in 8-bit mode.
287    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
288        be expressed in certain programming languages using Universal Character
289        Names.
291    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
292        which points out that "non characters" are not "characters that may not
293        appear in Unicode strings" but rather "characters that are reserved for
294        internal use and have only local meaning".
296    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
297        there was a conditional group that depended on an assertion, if the
298        assertion was false, the callout that immediately followed the alternation
299        in the condition was skipped when pcre_exec() was used for matching.
301    23. Allow an explicit callout to be inserted before an assertion that is the
302        condition for a conditional group, for compatibility with automatic
303        callouts, which always insert a callout at this point.
305    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
306        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
308    25. (*PRUNE) is now supported by the JIT compiler.
310    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
312    27. Fix the case where there are two or more SKIPs with arguments that may be
313        ignored.
315    28. (*SKIP) is now supported by the JIT compiler.
317    29. (*THEN) is now supported by the JIT compiler.
319    30. Update RunTest with additional test selector options.
321    31. The way PCRE handles backtracking verbs has been changed in two ways.
323        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
324        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
325        backtracking. In some cases this makes it more Perl-compatible, but Perl's
326        rather obscure rules do not always do the same thing.
328        (2) Previously, backtracking verbs were confined within assertions. This is
329        no longer the case for positive assertions, except for (*ACCEPT). Again,
330        this sometimes improves Perl compatibility, and sometimes does not.
332    32. A number of tests that were in test 2 because Perl did things differently
333        have been moved to test 1, because either Perl or PCRE has changed, and
334        these tests are now compatible.
336    32. Backtracking control verbs are now handled in the same way in JIT and
337        interpreter.
339    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
340        contained a forward subroutine reference caused a compile error.
342    34. Auto-detect and optimize limited repetitions in JIT.
344    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
345        blocking (*UTF) etc.
347    36. In the interpreter, maximizing pattern repetitions for characters and
348        character types now use tail recursion, which reduces stack usage.
350    37. The value of the max lookbehind was not correctly preserved if a compiled
351        and saved regex was reloaded on a host of different endianness.
353    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
354        of the compiled pattern block, expand the flags field from 16 to 32 bits
355        because it was almost full.
357    39. Try madvise first before posix_madvise.
359    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
360        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
361        original change locked out all matches of empty strings. This has been
362        changed so that one match of an empty string per line is recognized.
363        Subsequent searches on the same line (for colouring or for --only-matching,
364        for example) do not recognize empty strings.
366    41. Applied a user patch to fix a number of spelling mistakes in comments.
368    42. Data lines longer than 65536 caused pcretest to crash.
370    43. Clarified the data type for length and startoffset arguments for pcre_exec
371        and pcre_dfa_exec in the function-specific man pages, where they were
372        explicitly stated to be in bytes, never having been updated. I also added
373        some clarification to the pcreapi man page.
375    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
376        a segmentation fault.
379    Version 8.32 30-November-2012
380    -----------------------------
382    1.  Improved JIT compiler optimizations for first character search and single
383        character iterators.
385    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
386        Patch by Daniel Richard G.
388    3.  Single character iterator optimizations in the JIT compiler.
390    4.  Improved JIT compiler optimizations for character ranges.
392    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
393        Reported by Giuseppe D'Angelo.
395    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
396        of a line, was being set incorrectly in cases where .* appeared inside
397        atomic brackets at the start of a pattern, or where there was a subsequent
398        *PRUNE or *SKIP.
400    7.  Improved instruction cache flush for POWER/PowerPC.
401        Patch by Daniel Richard G.
403    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
404        grep:
406        (a) There is now no limit to the number of patterns to be matched.
408        (b) An error is given if a pattern is too long.
410        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
411            are now supported.
413        (d) --exclude-from and --include-from (multiple use) have been added.
415        (e) Exclusions and inclusions now apply to all files and directories, not
416            just to those obtained from scanning a directory recursively.
418        (f) Multiple uses of -f and --file-list are now supported.
420        (g) In a Windows environment, the default for -d has been changed from
421            "read" (the GNU grep default) to "skip", because otherwise the presence
422            of a directory in the file list provokes an error.
424        (h) The documentation has been revised and clarified in places.
426    9.  Improve the matching speed of capturing brackets.
428    10. Changed the meaning of \X so that it now matches a Unicode extended
429        grapheme cluster.
431    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
432        out POSIX threads when JIT support is configured.
434    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
436    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
437        structure could go wrong in environments where size_t is not the same size
438        as int.
440    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
441        set.
443    15. The EBCDIC support had decayed; later updates to the code had included
444        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
445        general tidy up of EBCDIC-related issues, and the documentation was also
446        not quite right. There is now a test that can be run on ASCII systems to
447        check some of the EBCDIC-related things (but is it not a full test).
449    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
450        in a small tidy to the code.
452    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
454    18. If the --only-matching (-o) option in pcregrep is specified multiple
455        times, each one causes appropriate output. For example, -o1 -o2 outputs the
456        substrings matched by the 1st and 2nd capturing parentheses. A separating
457        string can be specified by --om-separator (default empty).
459    19. Improving the first n character searches.
461    20. Turn case lists for horizontal and vertical white space into macros so that
462        they are defined only once.
464    21. This set of changes together give more compatible Unicode case-folding
465        behaviour for characters that have more than one other case when UCP
466        support is available.
468        (a) The Unicode property table now has offsets into a new table of sets of
469            three or more characters that are case-equivalent. The MultiStage2.py
470            script that generates these tables (the pcre_ucd.c file) now scans
471            CaseFolding.txt instead of UnicodeData.txt for character case
472            information.
474        (b) The code for adding characters or ranges of characters to a character
475            class has been abstracted into a generalized function that also handles
476            case-independence. In UTF-mode with UCP support, this uses the new data
477            to handle characters with more than one other case.
479        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
480            whose other case is greater than 256 are now correctly matched
481            caselessly. Previously, the high codepoint matched the low one, but not
482            vice versa.
484        (d) The processing of \h, \H, \v, and \ in character classes now makes use
485            of the new class addition function, using character lists defined as
486            macros alongside the case definitions of 20 above.
488        (e) Caseless back references now work with characters that have more than
489            one other case.
491        (f) General caseless matching of characters with more than one other case
492            is supported.
494    22. Unicode character properties were updated from Unicode 6.2.0
496    23. Improved CMake support under Windows. Patch by Daniel Richard G.
498    24. Add support for 32-bit character strings, and UTF-32
500    25. Major JIT compiler update (code refactoring and bugfixing).
501        Experimental Sparc 32 support is added.
503    26. Applied a modified version of Daniel Richard G's patch to create
504        pcre.h.generic and config.h.generic by "make" instead of in the
505        PrepareRelease script.
507    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
508        pcre_compile.c when checking for a zero character.
510    28. Introducing a native interface for JIT. Through this interface, the compiled
511        machine code can be directly executed. The purpose of this interface is to
512        provide fast pattern matching, so several sanity checks are not performed.
513        However, feature tests are still performed. The new interface provides
514        1.4x speedup compared to the old one.
516    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
517        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
518        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
520    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
521        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
522        the "old" RFC 2279). Instead, it ended up passing a negative length to
523        pcre_exec().
525    31. Add support for GCC's visibility feature to hide internal functions.
527    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
528        "unknown -C option" after outputting 0 or 1.
530    33. There is now support for generating a code coverage report for the test
531        suite in environments where gcc is the compiler and lcov is installed. This
532        is mainly for the benefit of the developers.
534    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
535        unaddressable using valgrind annotations, allowing valgrind to detect
536        invalid memory accesses. This is mainly for the benefit of the developers.
538    25. (*UTF) can now be used to start a pattern in any of the three libraries.
540    26. Give configure error if --enable-cpp but no C++ compiler found.
543    Version 8.31 06-July-2012
544    -------------------------
546    1.  Fixing a wrong JIT test case and some compiler warnings.
548    2.  Removed a bashism from the RunTest script.
550    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
551        to unsigned type, result still unsigned" that was given by an MS compiler
552        on encountering the code "-sizeof(xxx)".
554    4.  Partial matching support is added to the JIT compiler.
556    5.  Fixed several bugs concerned with partial matching of items that consist
557        of more than one character:
559        (a) /^(..)\1/ did not partially match "aba" because checking references was
560            done on an "all or nothing" basis. This also applied to repeated
561            references.
563        (b) \R did not give a hard partial match if \r was found at the end of the
564            subject.
566        (c) \X did not give a hard partial match after matching one or more
567            characters at the end of the subject.
569        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
570            a partial match for the string "\r".
572        (e) When newline was set to CRLF, the metacharacter "." did not recognize
573            a partial match for a CR character at the end of the subject string.
575    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
576        running pcretest, the text "(JIT)" added to the output whenever JIT is
577        actually used to run the match.
579    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
580        or /S+[+] with a digit between 1 and 7.
582    8.  OP_NOT now supports any UTF character not just single-byte ones.
584    9.  (*MARK) control verb is now supported by the JIT compiler.
586    10. The command "./RunTest list" lists the available tests without actually
587        running any of them. (Because I keep forgetting what they all are.)
591    12. Applied a (slightly modified) user-supplied patch that improves performance
592        when the heap is used for recursion (compiled with --disable-stack-for-
593        recursion). Instead of malloc and free for each heap frame each time a
594        logical recursion happens, frames are retained on a chain and re-used where
595        possible. This sometimes gives as much as 30% improvement.
597    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
598        call.
600    14. As documented, (*COMMIT) is now confined to within a positive assertion.
602    15. It is now possible to link pcretest with libedit as an alternative to
603        libreadline.
605    16. (*COMMIT) control verb is now supported by the JIT compiler.
607    17. The Unicode data tables have been updated to Unicode 6.1.0.
609    18. Added --file-list option to pcregrep.
611    19. Added binary file support to pcregrep, including the -a, --binary-files,
612        -I, and --text options.
614    20. The madvise function is renamed for posix_madvise for QNX compatibility
615        reasons. Fixed by Giuseppe D'Angelo.
617    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
619    22. Changed the option for creating symbolic links for 16-bit man pages from
620        -s to -sf so that re-installing does not cause issues.
622    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
624    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
625        matches in certain environments (the workspace was not being correctly
626        retained). Also added to pcre_dfa_exec() a simple plausibility check on
627        some of the workspace data at the beginning of a restart.
629    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
630        was not doing so when it should - probably a typo introduced by SVN 528
631        (change 8.10/14).
633    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
634        \w+ when the character tables indicated that \x{c4} was a word character.
635        There were several related cases, all because the tests for doing a table
636        lookup were testing for characters less than 127 instead of 255.
638    27. If a pattern contains capturing parentheses that are not used in a match,
639        their slots in the ovector are set to -1. For those that are higher than
640        any matched groups, this happens at the end of processing. In the case when
641        there were back references that the ovector was too small to contain
642        (causing temporary malloc'd memory to be used during matching), and the
643        highest capturing number was not used, memory off the end of the ovector
644        was incorrectly being set to -1. (It was using the size of the temporary
645        memory instead of the true size.)
647    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
648        ovector size, it uses memory at the end of the block that it has got.
650    29. Check for an overlong MARK name and give an error at compile time. The
651        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
653    30. JIT compiler update.
655    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
656        Rill for the patch.
658    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
660    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
662    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
663        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
664        was enabled.
666    35. Improve JIT code generation for greedy plus quantifier.
668    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
669        1 to "aa" instead of to an empty string. The bug affected repeated groups
670        that could potentially match an empty string.
672    37. Optimizing single character iterators in JIT.
674    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
675        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
676        codepoints that are too big for the mode are faulted, and in a UTF mode,
677        disallowed codepoints are also faulted.
679    39. If PCRE was compiled with UTF support, in three places in the DFA
680        matcher there was code that should only have been obeyed in UTF mode, but
681        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
682        processing when bytes with values greater than 127 were present. In 16-bit
683        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
684        both cases the values are those that cannot be the first data item in a UTF
685        character. The three items that might have provoked this were recursions,
686        possessively repeated groups, and atomic groups.
688    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
689        and pcregrep, because some OS require shared objects to be explicitly
690        passed to ld, causing the link step to fail if they are not.
692    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
693        mode, patterns that started with \h* or \R* might be incorrectly matched.
696    Version 8.30 04-February-2012
697    -----------------------------
699    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
700        name is defined in ctype.h.
702    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
703        only in quite long subpatterns.
705    3.  Removed the function pcre_info(), which has been obsolete and deprecated
706        since it was replaced by pcre_fullinfo() in February 2000.
708    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
709        match a (*MARK), and the match failed at the start of the subject, a
710        reference to memory before the start of the subject could occur. This bug
711        was introduced by fix 17 of release 8.21.
713    5.  A reference to an unset group with zero minimum repetition was giving
714        totally wrong answers (in non-JavaScript-compatibility mode). For example,
715        /(another)?(\1?)test/ matched against "hello world test". This bug was
716        introduced in release 8.13.
718    6.  Add support for 16-bit character strings (a large amount of work involving
719        many changes and refactorings).
721    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
722        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
723        from a file.
725    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
726        rounding is not applied in this particular case).
728    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
729        if they appear, or are escaped, in patterns.
731    10. Get rid of a number of -Wunused-but-set-variable warnings.
733    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
734        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
735        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
736        also returns the mark "x". This bug applied to capturing parentheses,
737        non-capturing parentheses, and atomic parentheses. It also applied to some
738        assertions.
740    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
741        information out of configure.ac instead of relying on pcre.h.generic, which
742        is not stored in the repository.
744    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
745        -lreadline.
747    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
749    15. Applied Graycode's patch to put the top-level frame on the stack rather
750        than the heap when not using the stack for recursion. This gives a
751        performance improvement in many cases when recursion is not deep.
753    16. Experimental code added to "pcretest -C" to output the stack frame size.
756    Version 8.21 12-Dec-2011
757    ------------------------
759    1.  Updating the JIT compiler.
761    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
762        are added as well.
764    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
765        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
766        calling _pcre_jit_exec. Some extra comments are added.
768    4.  (*MARK) settings inside atomic groups that do not contain any capturing
769        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
770        was introduced by change 18 for 8.20.
772    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
773        ECMA-262 standard.
775    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
776        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
777        This bug was probably introduced by change 9 of 8.13.
779    7.  While fixing 6 above, I noticed that a number of other items were being
780        incorrectly rejected as "not fixed length". This arose partly because newer
781        opcodes had not been added to the fixed-length checking code. I have (a)
782        corrected the bug and added tests for these items, and (b) arranged for an
783        error to occur if an unknown opcode is encountered while checking for fixed
784        length instead of just assuming "not fixed length". The items that were
785        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
786        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
787        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
789    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
790        being incorrectly compiled and would have given unpredicatble results.
792    9.  A possessively repeated subpattern with minimum repeat count greater than
793        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
794        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
795        the first (A) could occur when it should not.
797    10. Add a cast and remove a redundant test from the code.
799    11. JIT should use pcre_malloc/pcre_free for allocation.
801    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
802        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
803        is anything other than /usr, -L is still shown).
805    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
807    14. Perl does not support \N without a following name in a [] class; PCRE now
808        also gives an error.
810    15. If a forward reference was repeated with an upper limit of around 2000,
811        it caused the error "internal error: overran compiling workspace". The
812        maximum number of forward references (including repeats) was limited by the
813        internal workspace, and dependent on the LINK_SIZE. The code has been
814        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
815        the default depends on LINK_SIZE. There is a new upper limit (for safety)
816        of around 200,000 forward references. While doing this, I also speeded up
817        the filling in of repeated forward references.
819    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
820        incorrectly expecting the subject to contain another "a" after the start.
822    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
823        in the match, the SKIP should be ignored. This was not happening; instead
824        the SKIP was being treated as NOMATCH. For patterns such as
825        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
826        tested.
828    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
829        now much more compatible with Perl, in particular in cases where the result
830        is a non-match for a non-anchored pattern. For example, if
831        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
832        "m", where previously it did not return a name. A side effect of this
833        change is that for partial matches, the last encountered mark name is
834        returned, as for non matches. A number of tests that were previously not
835        Perl-compatible have been moved into the Perl-compatible test files. The
836        refactoring has had the pleasing side effect of removing one argument from
837        the match() function, thus reducing its stack requirements.
839    19. If the /S+ option was used in pcretest to study a pattern using JIT,
840        subsequent uses of /S (without +) incorrectly behaved like /S+.
842    21. Retrieve executable code size support for the JIT compiler and fixing
843        some warnings.
845    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
846        not work when the shorter character appeared right at the end of the
847        subject string.
849    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
850        systems.
852    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
853        output it when the /M option is used in pcretest.
855    25. The CheckMan script was not being included in the distribution. Also, added
856        an explicit "perl" to run Perl scripts from the PrepareRelease script
857        because this is reportedly needed in Windows.
859    26. If study data was being save in a file and studying had not found a set of
860        "starts with" bytes for the pattern, the data written to the file (though
861        never used) was taken from uninitialized memory and so caused valgrind to
862        complain.
864    27. Updated RunTest.bat as provided by Sheri Pierce.
866    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
868    29. Computation of memory usage for the table of capturing group names was
869        giving an unnecessarily large value.
872    Version 8.20 21-Oct-2011
873    ------------------------
875    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
876        a POSIX class. After further experiments with Perl, which convinced me that
877        Perl has bugs and confusions, a closing square bracket is no longer allowed
878        in a POSIX name. This bug also affected patterns with classes that started
879        with full stops.
881    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
882        captured substring, but while checking the failing first alternative,
883        substring 1 is temporarily captured. If the output vector supplied to
884        pcre_exec() was not big enough for this capture, the yield of the function
885        was still zero ("insufficient space for captured substrings"). This cannot
886        be totally fixed without adding another stack variable, which seems a lot
887        of expense for a edge case. However, I have improved the situation in cases
888        such as /(a)(b)x|abc/ matched against "abc", where the return code
889        indicates that fewer than the maximum number of slots in the ovector have
890        been set.
892    3.  Related to (2) above: when there are more back references in a pattern than
893        slots in the output vector, pcre_exec() uses temporary memory during
894        matching, and copies in the captures as far as possible afterwards. It was
895        using the entire output vector, but this conflicts with the specification
896        that only 2/3 is used for passing back captured substrings. Now it uses
897        only the first 2/3, for compatibility. This is, of course, another edge
898        case.
900    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
901        main code base, and can be used by building with --enable-jit. When this is
902        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
903        runtime --no-jit option is given.
905    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
906        ovector, the return from the function was zero, implying that there were
907        other matches that did not fit. The correct "exactly full" value is now
908        returned.
910    6.  If a subpattern that was called recursively or as a subroutine contained
911        (*PRUNE) or any other control that caused it to give a non-standard return,
912        invalid errors such as "Error -26 (nested recursion at the same subject
913        position)" or even infinite loops could occur.
915    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
916        computing the minimum length on reaching *ACCEPT, and so ended up with the
917        wrong value of 1 rather than 0. Further investigation indicates that
918        computing a minimum subject length in the presence of *ACCEPT is difficult
919        (think back references, subroutine calls), and so I have changed the code
920        so that no minimum is registered for a pattern that contains *ACCEPT.
922    8.  If (*THEN) was present in the first (true) branch of a conditional group,
923        it was not handled as intended. [But see 16 below.]
925    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
926        Sheri Pierce.
928    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
929        the first byte in a match must be "a".
931    11. Change 17 for 8.13 increased the recursion depth for patterns like
932        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
933        pattern contains any instances of (*THEN). If it does not, the old
934        optimizations are restored. It would be nice to do this on a per-group
935        basis, but at the moment that is not feasible.
937    12. In some environments, the output of pcretest -C is CRLF terminated. This
938        broke RunTest's code that checks for the link size. A single white space
939        character after the value is now allowed for.
941    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
942        For "fr", it uses the Windows-specific input and output files.
944    14. If (*THEN) appeared in a group that was called recursively or as a
945        subroutine, it did not work as intended. [But see next item.]
947    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
948        pattern fragments (but not containing any | characters). If A and B are
949        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
950        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
951        D. In other words, Perl considers parentheses that do not contain any |
952        characters to be part of a surrounding alternative, whereas PCRE was
953        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
954        differently. PCRE now behaves in the same way as Perl, except in the case
955        of subroutine/recursion calls such as (?1) which have in any case always
956        been different (but PCRE had them first :-).
958    16. Related to 15 above: Perl does not treat the | in a conditional group as
959        creating alternatives. Such a group is treated in the same way as an
960        ordinary group without any | characters when processing (*THEN). PCRE has
961        been changed to match Perl's behaviour.
963    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
964        RunGrepTest script failed.
966    18. Change 22 for version 13 caused atomic groups to use more stack. This is
967        inevitable for groups that contain captures, but it can lead to a lot of
968        stack use in large patterns. The old behaviour has been restored for atomic
969        groups that do not contain any capturing parentheses.
971    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
972        suppress the check for a minimum subject length at run time. (If it was
973        given to pcre_exec() or pcre_dfa_exec() it did work.)
975    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
976        fail to work when decoding hex characters in data strings in EBCDIC
977        environments.
979    21. It appears that in at least one Mac OS environment, the isxdigit() function
980        is implemented as a macro that evaluates to its argument more than once,
981        contravening the C 90 Standard (I haven't checked a later standard). There
982        was an instance in pcretest which caused it to go wrong when processing
983        \x{...} escapes in subject strings. The has been rewritten to avoid using
984        things like p++ in the argument of isxdigit().
987    Version 8.13 16-Aug-2011
988    ------------------------
990    1.  The Unicode data tables have been updated to Unicode 6.0.0.
992    2.  Two minor typos in pcre_internal.h have been fixed.
994    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
995        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
996        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
998    4.  There were a number of related bugs in the code for matching backrefences
999        caselessly in UTF-8 mode when codes for the characters concerned were
1000        different numbers of bytes. For example, U+023A and U+2C65 are an upper
1001        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1002        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1003        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1004        2-byte code at the end of the subject (it thought there wasn't enough data
1005        left).
1007    5.  Comprehensive information about what went wrong is now returned by
1008        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1009        as the output vector has at least 2 elements. The offset of the start of
1010        the failing character and a reason code are placed in the vector.
1012    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1013        now returned is for the first byte of the failing character, instead of the
1014        last byte inspected. This is an incompatible change, but I hope it is small
1015        enough not to be a problem. It makes the returned offset consistent with
1016        pcre_exec() and pcre_dfa_exec().
1018    7.  pcretest now gives a text phrase as well as the error number when
1019        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1020        failure, the offset and reason code are output.
1022    8.  When \R was used with a maximizing quantifier it failed to skip backwards
1023        over a \r\n pair if the subsequent match failed. Instead, it just skipped
1024        back over a single character (\n). This seems wrong (because it treated the
1025        two characters as a single entity when going forwards), conflicts with the
1026        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1027        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1028        has been changed.
1030    9.  Some internal refactoring has changed the processing so that the handling
1031        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1032        time (the PCRE_DOTALL option was changed this way some time ago: version
1033        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1034        which was always a bit of a fudge. It also means that there is one less
1035        argument for the match() function, which reduces its stack requirements
1036        slightly. This change also fixes an incompatibility with Perl: the pattern
1037        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1039    10. More internal refactoring has drastically reduced the number of recursive
1040        calls to match() for possessively repeated groups such as (abc)++ when
1041        using pcre_exec().
1043    11. While implementing 10, a number of bugs in the handling of groups were
1044        discovered and fixed:
1046        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1047        (a|)*(?1) gave a compile-time internal error.
1048        ((a|)+)+  did not notice that the outer group could match an empty string.
1049        (^a|^)+   was not marked as anchored.
1050        (.*a|.*)+ was not marked as matching at start or after a newline.
1052    12. Yet more internal refactoring has removed another argument from the match()
1053        function. Special calls to this function are now indicated by setting a
1054        value in a variable in the "match data" data block.
1056    13. Be more explicit in pcre_study() instead of relying on "default" for
1057        opcodes that mean there is no starting character; this means that when new
1058        ones are added and accidentally left out of pcre_study(), testing should
1059        pick them up.
1061    14. The -s option of pcretest has been documented for ages as being an old
1062        synonym of -m (show memory usage). I have changed it to mean "force study
1063        for every regex", that is, assume /S for every regex. This is similar to -i
1064        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1065        using it. It makes it easier to run collections of tests with and without
1066        study enabled, and thereby test pcre_study() more easily. All the standard
1067        tests are now run with and without -s (but some patterns can be marked as
1068        "never study" - see 20 below).
1070    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1071        restoration of the capturing data to the outer values was not happening
1072        correctly.
1074    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1075        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1076        pattern had matched an empty string, and so incorrectly returned a no
1077        match.
1079    17. There was optimizing code for the last branch of non-capturing parentheses,
1080        and also for the obeyed branch of a conditional subexpression, which used
1081        tail recursion to cut down on stack usage. Unfortunately, now that there is
1082        the possibility of (*THEN) occurring in these branches, tail recursion is
1083        no longer possible because the return has to be checked for (*THEN). These
1084        two optimizations have therefore been removed. [But see 8.20/11 above.]
1086    18. If a pattern containing \R was studied, it was assumed that \R always
1087        matched two bytes, thus causing the minimum subject length to be
1088        incorrectly computed because \R can also match just one byte.
1090    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1091        was incorrectly computed.
1093    20. If /S is present twice on a test pattern in pcretest input, it now
1094        *disables* studying, thereby overriding the use of -s on the command line
1095        (see 14 above). This is necessary for one or two tests to keep the output
1096        identical in both cases.
1098    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1099        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1101    22. When an atomic group that contained a capturing parenthesis was
1102        successfully matched, but the branch in which it appeared failed, the
1103        capturing was not being forgotten if a higher numbered group was later
1104        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1105        group 1 to "a", when in fact it should be unset. This applied to multi-
1106        branched capturing and non-capturing groups, repeated or not, and also to
1107        positive assertions (capturing in negative assertions does not happen
1108        in PCRE) and also to nested atomic groups.
1110    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1111        subject after a captured substring, to make it easier to tell which of a
1112        number of identical substrings has been captured.
1114    24. The way atomic groups are processed by pcre_exec() has been changed so that
1115        if they are repeated, backtracking one repetition now resets captured
1116        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1117        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1118        "aaa". Previously, it would have been "a". As part of this code
1119        refactoring, the way recursive calls are handled has also been changed.
1121    25. If an assertion condition captured any substrings, they were not passed
1122        back unless some other capturing happened later. For example, if
1123        (?(?=(a))a) was matched against "a", no capturing was returned.
1125    26. When studying a pattern that contained subroutine calls or assertions,
1126        the code for finding the minimum length of a possible match was handling
1127        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1128        group 1 called group 2 while simultaneously a separate group 2 called group
1129        1). A stack overflow occurred in this case. I have fixed this by limiting
1130        the recursion depth to 10.
1132    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1133        Fortmann. This supports explicit test numbers on the command line, and has
1134        argument validation and error reporting.
1136    28. An instance of \X with an unlimited repeat could fail if at any point the
1137        first character it looked at was a mark character.
1139    29. Some minor code refactoring concerning Unicode properties and scripts
1140        should reduce the stack requirement of match() slightly.
1142    30. Added the '=' option to pcretest to check the setting of unused capturing
1143        slots at the end of the pattern, which are documented as being -1, but are
1144        not included in the return count.
1146    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1147        compiled something random. Now it gives a compile-time error (as does
1148        Perl).
1150    32. A *MARK encountered during the processing of a positive assertion is now
1151        recorded and passed back (compatible with Perl).
1153    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1154        had alternative anchored branches, the search for a second match in a line
1155        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1156        matched the line "0102" twice. The same bug affected patterns that started
1157        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1158        twice.
1160    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1161        does, and because of capturing effects, quantifying parenthesized
1162        assertions may at times be useful. Quantifiers are now allowed for
1163        parenthesized assertions.
1165    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1167    36. \g was being checked for fancy things in a character class, when it should
1168        just be a literal "g".
1170    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1171        appearance of a nested POSIX class supersedes an apparent external class.
1172        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1173        unescaped square brackets may also appear as part of class names. For
1174        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1175        more like Perl. (But see 8.20/1 above.)
1177    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1178        was because it thought it was \N{name}, which is not supported).
1180    39. Add minix to OS list not supporting the -S option in pcretest.
1182    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1183        cannot analyze patterns in sufficient detail to catch mutual recursions
1184        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1185        subgroup is called recursively as a subpattern for a second time at the
1186        same position in the subject string. In previous releases this might have
1187        been caught by the recursion limit, or it might have run out of stack.
1189    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1190        happen only once. PCRE was, however incorrectly giving a compile time error
1191        "recursive call could loop indefinitely" because it cannot analyze the
1192        pattern in sufficient detail. The compile time test no longer happens when
1193        PCRE is compiling a conditional subpattern, but actual runaway loops are
1194        now caught at runtime (see 40 above).
1196    42. It seems that Perl allows any characters other than a closing parenthesis
1197        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1198        has been changed to be the same.
1200    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1201        as not to get warnings when autogen.sh is called. Also changed
1202        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1204    44. To help people who use pcregrep to scan files containing exceedingly long
1205        lines, the following changes have been made:
1207        (a) The default value of the buffer size parameter has been increased from
1208            8K to 20K. (The actual buffer used is three times this size.)
1210        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1211            PCRE is built.
1213        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1214            to be set at run time.
1216        (d) Numerical values in pcregrep options can be followed by K or M, for
1217            example --buffer-size=50K.
1219        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1220            given and the return code is set to 2.
1222    45. Add a pointer to the latest mark to the callout data block.
1224    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1225        partial match of an empty string instead of no match. This was specific to
1226        the use of ".".
1228    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1229        complete match instead of a partial match. This bug was dependent on both
1230        the PCRE_UTF8 and PCRE_DOTALL options being set.
1232    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1233        starting byte set, because \b was not being ignored.
1236    Version 8.12 15-Jan-2011
1237    ------------------------
1239    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1240        checks for such things as part of the documentation building process.
1242    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1243        --match-limit and --recursion-limit options (added for 8.11). In
1244        particular, this made one of the standard tests fail. (The integer value
1245        went into the wrong half of a long int.)
1247    3.  If the --colour option was given to pcregrep with -v (invert match), it
1248        did strange things, either producing crazy output, or crashing. It should,
1249        of course, ignore a request for colour when reporting lines that do not
1250        match.
1252    4.  Another pcregrep bug caused similar problems if --colour was specified with
1253        -M (multiline) and the pattern match finished with a line ending.
1255    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1256        matched in multiline mode, the following line was shown as part of the
1257        match. This seems wrong, so I have changed it.
1259    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1260        the check for further matches in the same line (so they could be coloured)
1261        to overrun the end of the current line. If another match was found, it was
1262        incorrectly shown (and then shown again when found in the next line).
1264    7.  If pcregrep was compiled under Windows, there was a reference to the
1265        function pcregrep_exit() before it was defined. I am assuming this was
1266        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1267        reported by a user. I've moved the definition above the reference.
1270    Version 8.11 10-Dec-2010
1271    ------------------------
1273    1.  (*THEN) was not working properly if there were untried alternatives prior
1274        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1275        backtracked to try for "b" instead of moving to the next alternative branch
1276        at the same level (in this case, to look for "c"). The Perl documentation
1277        is clear that when (*THEN) is backtracked onto, it goes to the "next
1278        alternative in the innermost enclosing group".
1280    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1281        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1282        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1283        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1284        (*THEN).
1286    3.  If \s appeared in a character class, it removed the VT character from
1287        the class, even if it had been included by some previous item, for example
1288        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1289        of \s, but is part of the POSIX "space" class.)
1291    4.  A partial match never returns an empty string (because you can always
1292        match an empty string at the end of the subject); however the checking for
1293        an empty string was starting at the "start of match" point. This has been
1294        changed to the "earliest inspected character" point, because the returned
1295        data for a partial match starts at this character. This means that, for
1296        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1297        (previously it gave "no match").
1299    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1300        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1301        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1302        has an implication that the given string is incomplete (because a partial
1303        match is preferred over a full match). For this reason, these items now
1304        give a partial match in this situation. [Aside: previously, the one case
1305        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1306        match rather than a full match, which was wrong by the old rules, but is
1307        now correct.]
1309    6.  There was a bug in the handling of #-introduced comments, recognized when
1310        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1311        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1312        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1313        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1314        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1315        places in pcre_compile().
1317    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1318        comments when looking ahead for named forward references to subpatterns,
1319        the only newline sequence it recognized was NL. It now handles newlines
1320        according to the set newline convention.
1322    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1323        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1324        cater for a lack of strerror(). These oversights have been fixed.
1326    9.  Added --match-limit and --recursion-limit to pcregrep.
1328    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1330    11. When the -o option was used, pcregrep was setting a return code of 1, even
1331        when matches were found, and --line-buffered was not being honoured.
1333    12. Added an optional parentheses number to the -o and --only-matching options
1334        of pcregrep.
1336    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1337        can match an empty string. The code to do it in pcretest and pcredemo
1338        needed fixing:
1340        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1341            only one byte after an empty string match just before CRLF (this case
1342            just got forgotten; "any" and "anycrlf" were OK).
1344        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1345            mode when an empty string match preceded an ASCII character followed by
1346            a non-ASCII character. (The code for advancing by one character rather
1347            than one byte was nonsense.)
1349        (c) The pcredemo.c sample program did not have any code at all to handle
1350            the cases when CRLF is a valid newline sequence.
1352    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1353        as a starting offset was within the subject string. There is now a new
1354        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1355        negative or greater than the length of the string. In order to test this,
1356        pcretest is extended to allow the setting of negative starting offsets.
1358    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1359        starting offset points to the beginning of a UTF-8 character was
1360        unnecessarily clumsy. I tidied it up.
1362    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1363        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1365    17. Nobody had reported that the --include_dir option, which was added in
1366        release 7.7 should have been called --include-dir (hyphen, not underscore)
1367        for compatibility with GNU grep. I have changed it to --include-dir, but
1368        left --include_dir as an undocumented synonym, and the same for
1369        --exclude-dir, though that is not available in GNU grep, at least as of
1370        release 2.5.4.
1372    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1373        characters from a string of bytes) have been redefined so as not to use
1374        loops, in order to improve performance in some environments. At the same
1375        time, I abstracted some of the common code into auxiliary macros to save
1376        repetition (this should not affect the compiled code).
1378    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1379        compile-time error is now given if \c is not followed by an ASCII
1380        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1381        different, and any byte value is allowed.)
1383    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1384        START_OPTIMIZE option, which is now allowed at compile time - but just
1385        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1386        to pcregrep and other applications that have no direct access to PCRE
1387        options. The new /Y option in pcretest sets this option when calling
1388        pcre_compile().
1390    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1391        back references. Groups containing recursive back references were forced to
1392        be atomic by that change, but in the case of named groups, the amount of
1393        memory required was incorrectly computed, leading to "Failed: internal
1394        error: code overflow". This has been fixed.
1396    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1397        pcretest.c, to avoid build problems in some Borland environments.
1400    Version 8.10 25-Jun-2010
1401    ------------------------
1403    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1404        THEN.
1406    2.  (*ACCEPT) was not working when inside an atomic group.
1408    3.  Inside a character class, \B is treated as a literal by default, but
1409        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1410        causes the error). The code is unchanged, but I tidied the documentation.
1412    4.  Inside a character class, PCRE always treated \R and \X as literals,
1413        whereas Perl faults them if its -w option is set. I have changed PCRE so
1414        that it faults them when PCRE_EXTRA is set.
1416    5.  Added support for \N, which always matches any character other than
1417        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1419    6.  When compiling pcregrep with newer versions of gcc which may have
1420        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1421        declared with attribute warn_unused_result" were given. Just casting the
1422        result to (void) does not stop the warnings; a more elaborate fudge is
1423        needed. I've used a macro to implement this.
1425    7.  Minor change to pcretest.c to avoid a compiler warning.
1427    8.  Added four artifical Unicode properties to help with an option to make
1428        \s etc use properties (see next item). The new properties are: Xan
1429        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1431    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1432        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1433        this option. Modified pcretest to add /W to test this facility. Added
1434        REG_UCP to make it available via the POSIX interface.
1436    10. Added --line-buffered to pcregrep.
1438    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1439        studied, and the match started with a letter with a code point greater than
1440        127 whose first byte was different to the first byte of the other case of
1441        the letter, the other case of this starting letter was not recognized
1442        (#976).
1444    12. If a pattern that was studied started with a repeated Unicode property
1445        test, for example, \p{Nd}+, there was the theoretical possibility of
1446        setting up an incorrect bitmap of starting bytes, but fortunately it could
1447        not have actually happened in practice until change 8 above was made (it
1448        added property types that matched character-matching opcodes).
1450    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1451        possible starting bytes for non-anchored patterns.
1453    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1454        \R, and also a number of cases that involve Unicode properties, both
1455        explicit and implicit when PCRE_UCP is set.
1457    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1458        input, it could crash or give wrong results if characters with values
1459        greater than 0xc0 were present in the subject string. (Detail: it assumed
1460        UTF-8 input when processing these items.)
1462    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1463        size_t is 64-bit (#991).
1465    17. Added a check for running out of memory when PCRE is compiled with
1466        --disable-stack-for-recursion (#990).
1468    18. If the last data line in a file for pcretest does not have a newline on
1469        the end, a newline was missing in the output.
1471    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1472        less than 128) in its various bitmaps. However, there is a facility for
1473        generating tables according to the current locale when PCRE is compiled. It
1474        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1475        characters, are recognized by isspace() and therefore were getting set in
1476        these tables, and indeed these tables seem to approximate to ISO 8859. This
1477        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1478        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1479        which of course cannot start UTF-8 characters. I have changed the code so
1480        that only real ASCII characters (less than 128) and the correct starting
1481        bytes for UTF-8 encodings are set for characters greater than 127 when in
1482        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1483        altogether.)
1485    20. Added the /T option to pcretest so as to be able to run tests with non-
1486        standard character tables, thus making it possible to include the tests
1487        used for 19 above in the standard set of tests.
1489    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1490        reference to a subpattern the other side of a comment that contains an
1491        opening parenthesis caused either an internal compiling error, or a
1492        reference to the wrong subpattern.
1495    Version 8.02 19-Mar-2010
1496    ------------------------
1498    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1500    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1501        configured.
1503    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1504        original author of that file, following a query about its status.
1506    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1507        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1509    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1510        quantifier applied to a forward-referencing subroutine call, could compile
1511        incorrect code or give the error "internal error: previously-checked
1512        referenced subpattern not found".
1514    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1515        variables to point to external functions. For these systems, therefore,
1516        pcre_malloc etc. are now initialized to local functions that call the
1517        relevant global functions.
1519    7.  There were two entries missing in the vectors called coptable and poptable
1520        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1521        I've fixed the data, and added a kludgy way of testing at compile time that
1522        the lengths are correct (equal to the number of opcodes).
1524    8.  Following on from 7, I added a similar kludge to check the length of the
1525        eint vector in pcreposix.c.
1527    9.  Error texts for pcre_compile() are held as one long string to avoid too
1528        much relocation at load time. To find a text, the string is searched,
1529        counting zeros. There was no check for running off the end of the string,
1530        which could happen if a new error number was added without updating the
1531        string.
1533    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1535    11. \K was not working if it appeared in an atomic group or in a group that
1536        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1537        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1538        the assertion is positive, but not if it is negative.
1540    12. Change 11 fortuitously reduced the size of the stack frame used in the
1541        "match()" function of pcre_exec.c by one pointer. Forthcoming
1542        implementation of support for (*MARK) will need an extra pointer on the
1543        stack; I have reserved it now, so that the stack frame size does not
1544        decrease.
1546    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1547        item in branch that calls a recursion is a subroutine call - as in the
1548        second branch in the above example - was incorrectly given the compile-
1549        time error "recursive call could loop indefinitely" because pcre_compile()
1550        was not correctly checking the subroutine for matching a non-empty string.
1552    14. The checks for overrunning compiling workspace could trigger after an
1553        overrun had occurred. This is a "should never occur" error, but it can be
1554        triggered by pathological patterns such as hundreds of nested parentheses.
1555        The checks now trigger 100 bytes before the end of the workspace.
1557    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1560    Version 8.01 19-Jan-2010
1561    ------------------------
1563    1.  If a pattern contained a conditional subpattern with only one branch (in
1564        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1565        computed the wrong minimum data length (which is of course zero for such
1566        subpatterns). This could cause incorrect "no match" results.
1568    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1569        the pattern is reset in the first branch, pcre_compile() failed with
1570        "internal error: code overflow at offset...". This happened only when
1571        the reset was to the original external option setting. (An optimization
1572        abstracts leading options settings into an external setting, which was the
1573        cause of this.)
1575    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1576        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1577        assertion pattern did not match (meaning that the assertion was true), it
1578        was incorrectly treated as false if the SKIP had been reached during the
1579        matching. This also applied to assertions used as conditions.
1581    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1582        assertion subpattern, including such a pattern used as a condition,
1583        unpredictable results occurred, instead of the error return
1586    5.  The C++ GlobalReplace function was not working like Perl for the special
1587        situation when an empty string is matched. It now does the fancy magic
1588        stuff that is necessary.
1590    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1591        removed. (These were left over from very, very early versions of PCRE.)
1593    7.  Some cosmetic changes to the code to make life easier when compiling it
1594        as part of something else:
1596        (a) Change DEBUG to PCRE_DEBUG.
1598        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1599            called "current" as "current_branch", to prevent a collision with the
1600            Linux macro when compiled as a kernel module.
1602        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1603            prevent a collision with the Linux macro when compiled as a kernel
1604            module.
1606    8.  In pcre_compile() there are some checks for integer overflows that used to
1607        cast potentially large values to (double). This has been changed to that
1608        when building, a check for int64_t is made, and if it is found, it is used
1609        instead, thus avoiding the use of floating point arithmetic. (There is no
1610        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1611        double.
1613    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1614        2005 (difference between two addresses compared to an unsigned value).
1616    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1617        custom one, because of the following reported problem in Windows:
1619          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1620              under Win32.
1621          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1622              therefore missing the function definition.
1623          - The compiler thus generates a "C" signature for the test function.
1624          - The linker fails to find the "C" function.
1625          - PCRE fails to configure if asked to do so against libbz2.
1627    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1628        messages were output:
1630          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1631          rerunning libtoolize, to keep the correct libtool macros in-tree.
1632          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1634        I have done both of these things.
1636    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1637        most of the time, it *can* run out if it is given a pattern that contains a
1638        runaway infinite recursion. I updated the discussion in the pcrestack man
1639        page.
1641    13. Now that we have gone to the x.xx style of version numbers, the minor
1642        version may start with zero. Using 08 or 09 is a bad idea because users
1643        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1644        interpreted as invalid octal numbers. I've updated the previous comment in
1645        configure.ac, and also added a check that gives an error if 08 or 09 are
1646        used.
1648    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1649        causing partial matching to fail when the end of the subject matched \W
1650        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1652    15. There were some discrepancies between the declarations in pcre_internal.h
1653        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1654        their definitions. The declarations used "const uschar *" and the
1655        definitions used USPTR. Even though USPTR is normally defined as "const
1656        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1657        reported that: "This difference in casting confuses some C++ compilers, for
1658        example, SunCC recognizes above declarations as different functions and
1659        generates broken code for hbpcre." I have changed the declarations to use
1660        USPTR.
1662    16. GNU libtool is named differently on some systems. The autogen.sh script now
1663        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1664        (FreeBSD).
1666    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1667        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1668        comment: "Figure out how to create a longlong from a string: strtoll and
1669        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1670        instance, but it only takes 2 args instead of 3!"
1672    18. A subtle bug concerned with back references has been fixed by a change of
1673        specification, with a corresponding code fix. A pattern such as
1674        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1675        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1676        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1677        same bug. Such groups have to be quantified to be useful, or contained
1678        inside another quantified group. (If there's no repetition, the reference
1679        can never match.) The problem arises because, having left the group and
1680        moved on to the rest of the pattern, a later failure that backtracks into
1681        the group uses the captured value from the final iteration of the group
1682        rather than the correct earlier one. I have fixed this in PCRE by forcing
1683        any group that contains a reference to itself to be an atomic group; that
1684        is, there cannot be any backtracking into it once it has completed. This is
1685        similar to recursive and subroutine calls.
1688    Version 8.00 19-Oct-09
1689    ----------------------
1691    1.  The table for translating pcre_compile() error codes into POSIX error codes
1692        was out-of-date, and there was no check on the pcre_compile() error code
1693        being within the table. This could lead to an OK return being given in
1694        error.
1696    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1697        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1698        in a Windows environment.
1700    3.  The pcregrep --count option prints the count for each file even when it is
1701        zero, as does GNU grep. However, pcregrep was also printing all files when
1702        --files-with-matches was added. Now, when both options are given, it prints
1703        counts only for those files that have at least one match. (GNU grep just
1704        prints the file name in this circumstance, but including the count seems
1705        more useful - otherwise, why use --count?) Also ensured that the
1706        combination -clh just lists non-zero counts, with no names.
1708    4.  The long form of the pcregrep -F option was incorrectly implemented as
1709        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1710        but it seems right to fix it, and I didn't think it was worth preserving
1711        the old behaviour.
1713    5.  The command line items --regex=pattern and --regexp=pattern were not
1714        recognized by pcregrep, which required --regex pattern or --regexp pattern
1715        (with a space rather than an '='). The man page documented the '=' forms,
1716        which are compatible with GNU grep; these now work.
1718    6.  No libpcreposix.pc file was created for pkg-config; there was just
1719        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1721    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1722        when UCP support is not needed, by modifying the Python script that
1723        generates it from Unicode data files. This should not matter if the module
1724        is correctly used as a library, but I received one complaint about 50K of
1725        unwanted data. My guess is that the person linked everything into his
1726        program rather than using a library. Anyway, it does no harm.
1728    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1729        was a minimum greater than 1 for a wide character in a possessive
1730        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1731        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1732        character. Chaos in the form of incorrect output or a compiling loop could
1733        result.
1735    9.  The restrictions on what a pattern can contain when partial matching is
1736        requested for pcre_exec() have been removed. All patterns can now be
1737        partially matched by this function. In addition, if there are at least two
1738        slots in the offset vector, the offset of the earliest inspected character
1739        for the match and the offset of the end of the subject are set in them when
1740        PCRE_ERROR_PARTIAL is returned.
1742    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1743        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1744        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1745        and may be more useful for multi-segment matching.
1747    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1748        used to be given if ever the end of the subject was reached; now it is
1749        given only if matching could not proceed because another character was
1750        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1751        string "Z", which now yields "no match" instead of "partial match". In the
1752        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1753        final character ended with (*FAIL).
1755    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1756        if the pattern had a "must contain" character that was already found in the
1757        earlier partial match, unless partial matching was again requested. For
1758        example, with the pattern /dog.(body)?/, the "must contain" character is
1759        "g". If the first part-match was for the string "dog", restarting with
1760        "sbody" failed. This bug has been fixed.
1762    13. The string returned by pcre_dfa_exec() after a partial match has been
1763        changed so that it starts at the first inspected character rather than the
1764        first character of the match. This makes a difference only if the pattern
1765        starts with a lookbehind assertion or \b or \B (\K is not supported by
1766        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1767        matching functions compatible, and I think it's the right thing to do.
1769    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1770        so that the demonstration program is easily available in environments where
1771        PCRE has not been installed from source.
1773    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1774        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1775        library.
1777    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1778        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1779        is not the first non-POSIX option to be added. Clearly some people find
1780        these options useful.
1782    17. If a caller to the POSIX matching function regexec() passes a non-zero
1783        value for nmatch with a NULL value for pmatch, the value of
1784        nmatch is forced to zero.
1786    18. RunGrepTest did not have a test for the availability of the -u option of
1787        the diff command, as RunTest does. It now checks in the same way as
1788        RunTest, and also checks for the -b option.
1790    19. If an odd number of negated classes containing just a single character
1791        interposed, within parentheses, between a forward reference to a named
1792        subpattern and the definition of the subpattern, compilation crashed with
1793        an internal error, complaining that it could not find the referenced
1794        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1795        [The bug was that it was starting one character too far in when skipping
1796        over the character class, thus treating the ] as data rather than
1797        terminating the class. This meant it could skip too much.]
1799    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1800        /g option in pcretest when the pattern contains \K, which makes it possible
1801        to have an empty string match not at the start, even when the pattern is
1802        anchored. Updated pcretest and pcredemo to use this option.
1804    21. If the maximum number of capturing subpatterns in a recursion was greater
1805        than the maximum at the outer level, the higher number was returned, but
1806        with unset values at the outer level. The correct (outer level) value is
1807        now given.
1809    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1810        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1811        make it do so. The string so far is captured, making this feature
1812        compatible with Perl.
1814    23. The tests have been re-organized, adding tests 11 and 12, to make it
1815        possible to check the Perl 5.10 features against Perl 5.10.
1817    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1818        pattern matches a fixed length string. PCRE did not allow this; now it
1819        does. Neither allows recursion.
1821    25. I finally figured out how to implement a request to provide the minimum
1822        length of subject string that was needed in order to match a given pattern.
1823        (It was back references and recursion that I had previously got hung up
1824        on.) This code has now been added to pcre_study(); it finds a lower bound
1825        to the length of subject needed. It is not necessarily the greatest lower
1826        bound, but using it to avoid searching strings that are too short does give
1827        some useful speed-ups. The value is available to calling programs via
1828        pcre_fullinfo().
1830    26. While implementing 25, I discovered to my embarrassment that pcretest had
1831        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1832        study optimizations had never been tested with that matching function.
1833        Oops. What is worse, even when it was passed study data, there was a bug in
1834        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1835        were also very few tests of studied patterns with pcre_dfa_exec().
1837    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1838        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1839        on the other side of the coin, they are no longer allowed to have different
1840        names, because these cannot be distinguished in PCRE, and this has caused
1841        confusion. (This is a difference from Perl.)
1843    28. When duplicate subpattern names are present (necessarily with different
1844        numbers, as required by 27 above), and a test is made by name in a
1845        conditional pattern, either for a subpattern having been matched, or for
1846        recursion in such a pattern, all the associated numbered subpatterns are
1847        tested, and the overall condition is true if the condition is true for any
1848        one of them. This is the way Perl works, and is also more like the way
1849        testing by number works.
1852    Version 7.9 11-Apr-09
1853    ---------------------
1855    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1856        (pcretest), all targets were linked against these libraries. This included
1857        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1858        libraries. This caused unwanted dependencies to be created. This problem
1859        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1860        pcretest is linked with readline.
1862    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1863        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1864        moved outside it again, because FALSE and TRUE are already defined in AIX,
1865        but BOOL is not.
1867    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1868        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1870    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1871        hyphens) following file names and line numbers when outputting matching
1872        lines. This is not true; no spaces are inserted. I have also clarified the
1873        wording for the --colour (or --color) option.
1875    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1876        was not coloured; this is different to GNU grep, so I have changed it to be
1877        the same.
1879    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1880        each matching line was coloured. Now it goes on to look for further matches
1881        of any of the test patterns, which is the same behaviour as GNU grep.
1883    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1884        doesn't make sense to accept an empty string match in pcregrep, so I have
1885        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1886        seems to be how GNU grep behaves. [But see later change 40 for release
1887        8.33.]
1889    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1890        start or after a newline", because the conditional assertion was not being
1891        correctly handled. The rule now is that both the assertion and what follows
1892        in the first alternative must satisfy the test.
1894    9.  If auto-callout was enabled in a pattern with a conditional group whose
1895        condition was an assertion, PCRE could crash during matching, both with
1896        pcre_exec() and pcre_dfa_exec().
1898    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1899        used for matching.
1901    11. Unicode property support in character classes was not working for
1902        characters (bytes) greater than 127 when not in UTF-8 mode.
1904    12. Added the -M command line option to pcretest.
1906    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1908    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1910    16. Added comments and documentation about mis-use of no_arg in the C++
1911        wrapper.
1913    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1914        from Martin Jerabek that uses macro names for all relevant character and
1915        string constants.
1917    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1918        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1919        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1920        these, but not everybody uses configure.
1922    19. A conditional group that had only one branch was not being correctly
1923        recognized as an item that could match an empty string. This meant that an
1924        enclosing group might also not be so recognized, causing infinite looping
1925        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1926        with the subject "ab", where knowledge that the repeated group can match
1927        nothing is needed in order to break the loop.
1929    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1930        exec(), but without supplying a callout function, matching went wrong.
1932    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1933        leak if the size of the offset vector was greater than 30. When the vector
1934        is smaller, the saved offsets during recursion go onto a local stack
1935        vector, but for larger vectors malloc() is used. It was failing to free
1936        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1937        error, in fact).
1939    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1940        heapframe that is used only when UTF-8 support is enabled. This caused no
1941        problem, but was untidy.
1943    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1944        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1945        included within another project.
1947    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1948        slightly modified by me:
1950          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1951              not building pcregrep.
1953          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1954              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1956    25. Forward references, both numeric and by name, in patterns that made use of
1957        duplicate group numbers, could behave incorrectly or give incorrect errors,
1958        because when scanning forward to find the reference group, PCRE was not
1959        taking into account the duplicate group numbers. A pattern such as
1960        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1962    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1963        the feature of a custom pointer more persuasive (as requested by a user).
1965    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1966        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1967        pre-defined.
1969    28. Added support for (*UTF8) at the start of a pattern.
1971    29. Arrange for flags added by the "release type" setting in CMake to be shown
1972        in the configuration summary.
1975    Version 7.8 05-Sep-08
1976  ---------------------  ---------------------
1978  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
# Line 31  Version 8.0 02 Jul-08 Line 2002  Version 8.0 02 Jul-08
2003  7.  Added two (int) casts to pcregrep when printing the difference of two  7.  Added two (int) casts to pcregrep when printing the difference of two
2004      pointers, in case they are 64-bit values.      pointers, in case they are 64-bit values.
2006  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
2007      test 2 if it fails.      test 2 if it fails.
2009  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2010      and a #define of that name to empty if it is not externally set. This is to      and a #define of that name to empty if it is not externally set. This is to
2011      allow users of MSVC to set it if necessary.      allow users of MSVC to set it if necessary.
2013  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2014      the convenience functions in the pcre_get.c source file.      the convenience functions in the pcre_get.c source file.
2016  11. An option change at the start of a pattern that had top-level alternatives  11. An option change at the start of a pattern that had top-level alternatives
2017      could cause overwriting and/or a crash. This command provoked a crash in      could cause overwriting and/or a crash. This command provoked a crash in
2018      some environments:      some environments:
2020        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2022      This potential security problem was recorded as CVE-2008-2371.      This potential security problem was recorded as CVE-2008-2371.
2024    12. For a pattern where the match had to start at the beginning or immediately
2025        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2026        pcre_dfa_exec() could read past the end of the passed subject if there was
2027        no match. To help with detecting such bugs (e.g. with valgrind), I modified
2028        pcretest so that it places the subject at the end of its malloc-ed buffer.
2030    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2031        exec() might read past the end of the data buffer in UTF-8 mode.
2033    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2034        the data contained the byte 0x85 as part of a UTF-8 character within its
2035        first line. This applied both to normal and DFA matching.
2037    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2038        /^[^d]*?$/8 failed to match "abc".
2040    16. Added a missing copyright notice to pcrecpp_internal.h.
2042    17. Make it more clear in the documentation that values returned from
2043        pcre_exec() in ovector are byte offsets, not character counts.
2045    18. Tidied a few places to stop certain compilers from issuing warnings.
2047    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2048        supplied by Stefan Weber. I made a further small update for 7.8 because
2049        there is a change of source arrangements: the pcre_searchfuncs.c module is
2050        replaced by pcre_ucd.c.
2053  Version 7.7 07-May-08  Version 7.7 07-May-08
2054  ---------------------  ---------------------
# Line 128  Version 7.7 07-May-08 Line 2127  Version 7.7 07-May-08
2127      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2128      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2129      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2130      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2131      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2132      was subsequently set up correctly.)      was subsequently set up correctly.)

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