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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-08  Version 8.34 xx-xxxx-201x
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_POSSESSIFY is added for testing purposes, and the -O and /O
89        options in pcretest are provided to set it.
91    18. The character VT has been added to the set of characters that match \s and
92        are generally treated as white space, following this same change in Perl
93        5.18. There is now no difference between "Perl space" and "POSIX space".
95    19. The code for checking named groups as conditions, either for being set or
96        for being recursed, has been refactored (this is related to 14 and 15
97        above). Processing unduplicated named groups should now be as fast at
98        numerical groups, and processing duplicated groups should be faster than
99        before.
101    20. Two patches to the CMake build system, by Alexander Barkov:
103          (1) Replace the "source" command by "." in CMakeLists.txt because
104              "source" is a bash-ism.
106          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
107              without these the CMake build does not work on Solaris.
109    21. Perl has changed its handling of \8 and \9. If there is no previously
110        encountered capturing group of those numbers, they are treated as the
111        literal characters 8 and 9 instead of a binary zero followed by the
112        literals. PCRE now does the same.
114    22. Following Perl, added \o{} to specify codepoints in octal, making it
115        possible to specify values greater than 0777 and also making them
116        unambiguous.
118    23. Perl now gives an error for missing closing braces after \x{... instead of
119        treating the string as literal. PCRE now does the same.
121    24. RunTest used to grumble if an inappropriate test was selected explicitly,
122        but just skip it when running all tests. This make it awkward to run ranges
123        of tests when one of them was inappropriate. Now it just skips any
124        inappropriate tests, as it always did when running all tests.
126    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
127        character types such as \d or \w, too many callouts were inserted, and the
128        data that they returned was rubbish.
130    26. In UCP mode, \s was not matching two of the characters that Perl matches,
131        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
132        were matched by \h. The code has now been refactored so that the lists of
133        the horizontal and vertical whitespace characters used for \h and \v (which
134        are defined only in one place) are now also used for \s.
137    Version 8.33 28-May-2013
138    ------------------------
140    1.  Added 'U' to some constants that are compared to unsigned integers, to
141        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
142        variables that are added to signed variables, to ensure the result is
143        signed and can be negated.
145    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
146        CMake config files.
148    3.  Revise the creation of config.h.generic so that all boolean macros are
149        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
150        overriding via -D on the command line possible.
152    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
153        to unsigned int is reported to make a quite noticeable speed difference in
154        a specific Windows environment. Testing on Linux did also appear to show
155        some benefit (and it is clearly not harmful). Also fixed the definition of
156        Xop which should be unsigned.
158    5.  Related to (4), changing the definition of the intermediate variable cc
159        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
160        improvements.
162    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
163        unnecessary spaces.
165    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
166        and later.
168    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
170    9.  Optimizing fast_forward_start_bits in JIT.
172    10. Adding support for callouts in JIT, and fixing some issues revealed
173        during this work. Namely:
175        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
177        (b) Minimum length was not checked before the matching is started.
179    11. The value of capture_last that is passed to callouts was incorrect in some
180        cases when there was a capture on one path that was subsequently abandoned
181        after a backtrack. Also, the capture_last value is now reset after a
182        recursion, since all captures are also reset in this case.
184    12. The interpreter no longer returns the "too many substrings" error in the
185        case when an overflowing capture is in a branch that is subsequently
186        abandoned after a backtrack.
188    13. In the pathological case when an offset vector of size 2 is used, pcretest
189        now prints out the matched string after a yield of 0 or 1.
191    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
192        Only supported by the JIT compiler at the moment.
194    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
196    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
197        offset of the starting point of the matching process, provided the offsets
198        vector is large enough.
200    17. The \A escape now records a lookbehind value of 1, though its execution
201        does not actually inspect the previous character. This is to ensure that,
202        in partial multi-segment matching, at least one character from the old
203        segment is retained when a new segment is processed. Otherwise, if there
204        are no lookbehinds in the pattern, \A might match incorrectly at the start
205        of a new segment.
207    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
209    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
210        gives some modest performance improvement in 8-bit mode.
212    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
213        be expressed in certain programming languages using Universal Character
214        Names.
216    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
217        which points out that "non characters" are not "characters that may not
218        appear in Unicode strings" but rather "characters that are reserved for
219        internal use and have only local meaning".
221    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
222        there was a conditional group that depended on an assertion, if the
223        assertion was false, the callout that immediately followed the alternation
224        in the condition was skipped when pcre_exec() was used for matching.
226    23. Allow an explicit callout to be inserted before an assertion that is the
227        condition for a conditional group, for compatibility with automatic
228        callouts, which always insert a callout at this point.
230    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
231        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
233    25. (*PRUNE) is now supported by the JIT compiler.
235    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
237    27. Fix the case where there are two or more SKIPs with arguments that may be
238        ignored.
240    28. (*SKIP) is now supported by the JIT compiler.
242    29. (*THEN) is now supported by the JIT compiler.
244    30. Update RunTest with additional test selector options.
246    31. The way PCRE handles backtracking verbs has been changed in two ways.
248        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
249        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
250        backtracking. In some cases this makes it more Perl-compatible, but Perl's
251        rather obscure rules do not always do the same thing.
253        (2) Previously, backtracking verbs were confined within assertions. This is
254        no longer the case for positive assertions, except for (*ACCEPT). Again,
255        this sometimes improves Perl compatibility, and sometimes does not.
257    32. A number of tests that were in test 2 because Perl did things differently
258        have been moved to test 1, because either Perl or PCRE has changed, and
259        these tests are now compatible.
261    32. Backtracking control verbs are now handled in the same way in JIT and
262        interpreter.
264    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
265        contained a forward subroutine reference caused a compile error.
267    34. Auto-detect and optimize limited repetitions in JIT.
269    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
270        blocking (*UTF) etc.
272    36. In the interpreter, maximizing pattern repetitions for characters and
273        character types now use tail recursion, which reduces stack usage.
275    37. The value of the max lookbehind was not correctly preserved if a compiled
276        and saved regex was reloaded on a host of different endianness.
278    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
279        of the compiled pattern block, expand the flags field from 16 to 32 bits
280        because it was almost full.
282    39. Try madvise first before posix_madvise.
284    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
285        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
286        original change locked out all matches of empty strings. This has been
287        changed so that one match of an empty string per line is recognized.
288        Subsequent searches on the same line (for colouring or for --only-matching,
289        for example) do not recognize empty strings.
291    41. Applied a user patch to fix a number of spelling mistakes in comments.
293    42. Data lines longer than 65536 caused pcretest to crash.
295    43. Clarified the data type for length and startoffset arguments for pcre_exec
296        and pcre_dfa_exec in the function-specific man pages, where they were
297        explicitly stated to be in bytes, never having been updated. I also added
298        some clarification to the pcreapi man page.
300    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
301        a segmentation fault.
304    Version 8.32 30-November-2012
305    -----------------------------
307    1.  Improved JIT compiler optimizations for first character search and single
308        character iterators.
310    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
311        Patch by Daniel Richard G.
313    3.  Single character iterator optimizations in the JIT compiler.
315    4.  Improved JIT compiler optimizations for character ranges.
317    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
318        Reported by Giuseppe D'Angelo.
320    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
321        of a line, was being set incorrectly in cases where .* appeared inside
322        atomic brackets at the start of a pattern, or where there was a subsequent
323        *PRUNE or *SKIP.
325    7.  Improved instruction cache flush for POWER/PowerPC.
326        Patch by Daniel Richard G.
328    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
329        grep:
331        (a) There is now no limit to the number of patterns to be matched.
333        (b) An error is given if a pattern is too long.
335        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
336            are now supported.
338        (d) --exclude-from and --include-from (multiple use) have been added.
340        (e) Exclusions and inclusions now apply to all files and directories, not
341            just to those obtained from scanning a directory recursively.
343        (f) Multiple uses of -f and --file-list are now supported.
345        (g) In a Windows environment, the default for -d has been changed from
346            "read" (the GNU grep default) to "skip", because otherwise the presence
347            of a directory in the file list provokes an error.
349        (h) The documentation has been revised and clarified in places.
351    9.  Improve the matching speed of capturing brackets.
353    10. Changed the meaning of \X so that it now matches a Unicode extended
354        grapheme cluster.
356    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
357        out POSIX threads when JIT support is configured.
359    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
361    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
362        structure could go wrong in environments where size_t is not the same size
363        as int.
365    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
366        set.
368    15. The EBCDIC support had decayed; later updates to the code had included
369        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
370        general tidy up of EBCDIC-related issues, and the documentation was also
371        not quite right. There is now a test that can be run on ASCII systems to
372        check some of the EBCDIC-related things (but is it not a full test).
374    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
375        in a small tidy to the code.
377    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
379    18. If the --only-matching (-o) option in pcregrep is specified multiple
380        times, each one causes appropriate output. For example, -o1 -o2 outputs the
381        substrings matched by the 1st and 2nd capturing parentheses. A separating
382        string can be specified by --om-separator (default empty).
384    19. Improving the first n character searches.
386    20. Turn case lists for horizontal and vertical white space into macros so that
387        they are defined only once.
389    21. This set of changes together give more compatible Unicode case-folding
390        behaviour for characters that have more than one other case when UCP
391        support is available.
393        (a) The Unicode property table now has offsets into a new table of sets of
394            three or more characters that are case-equivalent. The MultiStage2.py
395            script that generates these tables (the pcre_ucd.c file) now scans
396            CaseFolding.txt instead of UnicodeData.txt for character case
397            information.
399        (b) The code for adding characters or ranges of characters to a character
400            class has been abstracted into a generalized function that also handles
401            case-independence. In UTF-mode with UCP support, this uses the new data
402            to handle characters with more than one other case.
404        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
405            whose other case is greater than 256 are now correctly matched
406            caselessly. Previously, the high codepoint matched the low one, but not
407            vice versa.
409        (d) The processing of \h, \H, \v, and \ in character classes now makes use
410            of the new class addition function, using character lists defined as
411            macros alongside the case definitions of 20 above.
413        (e) Caseless back references now work with characters that have more than
414            one other case.
416        (f) General caseless matching of characters with more than one other case
417            is supported.
419    22. Unicode character properties were updated from Unicode 6.2.0
421    23. Improved CMake support under Windows. Patch by Daniel Richard G.
423    24. Add support for 32-bit character strings, and UTF-32
425    25. Major JIT compiler update (code refactoring and bugfixing).
426        Experimental Sparc 32 support is added.
428    26. Applied a modified version of Daniel Richard G's patch to create
429        pcre.h.generic and config.h.generic by "make" instead of in the
430        PrepareRelease script.
432    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
433        pcre_compile.c when checking for a zero character.
435    28. Introducing a native interface for JIT. Through this interface, the compiled
436        machine code can be directly executed. The purpose of this interface is to
437        provide fast pattern matching, so several sanity checks are not performed.
438        However, feature tests are still performed. The new interface provides
439        1.4x speedup compared to the old one.
441    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
442        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
443        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
445    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
446        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
447        the "old" RFC 2279). Instead, it ended up passing a negative length to
448        pcre_exec().
450    31. Add support for GCC's visibility feature to hide internal functions.
452    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
453        "unknown -C option" after outputting 0 or 1.
455    33. There is now support for generating a code coverage report for the test
456        suite in environments where gcc is the compiler and lcov is installed. This
457        is mainly for the benefit of the developers.
459    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
460        unaddressable using valgrind annotations, allowing valgrind to detect
461        invalid memory accesses. This is mainly for the benefit of the developers.
463    25. (*UTF) can now be used to start a pattern in any of the three libraries.
465    26. Give configure error if --enable-cpp but no C++ compiler found.
468    Version 8.31 06-July-2012
469    -------------------------
471    1.  Fixing a wrong JIT test case and some compiler warnings.
473    2.  Removed a bashism from the RunTest script.
475    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
476        to unsigned type, result still unsigned" that was given by an MS compiler
477        on encountering the code "-sizeof(xxx)".
479    4.  Partial matching support is added to the JIT compiler.
481    5.  Fixed several bugs concerned with partial matching of items that consist
482        of more than one character:
484        (a) /^(..)\1/ did not partially match "aba" because checking references was
485            done on an "all or nothing" basis. This also applied to repeated
486            references.
488        (b) \R did not give a hard partial match if \r was found at the end of the
489            subject.
491        (c) \X did not give a hard partial match after matching one or more
492            characters at the end of the subject.
494        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
495            a partial match for the string "\r".
497        (e) When newline was set to CRLF, the metacharacter "." did not recognize
498            a partial match for a CR character at the end of the subject string.
500    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
501        running pcretest, the text "(JIT)" added to the output whenever JIT is
502        actually used to run the match.
504    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
505        or /S+[+] with a digit between 1 and 7.
507    8.  OP_NOT now supports any UTF character not just single-byte ones.
509    9.  (*MARK) control verb is now supported by the JIT compiler.
511    10. The command "./RunTest list" lists the available tests without actually
512        running any of them. (Because I keep forgetting what they all are.)
516    12. Applied a (slightly modified) user-supplied patch that improves performance
517        when the heap is used for recursion (compiled with --disable-stack-for-
518        recursion). Instead of malloc and free for each heap frame each time a
519        logical recursion happens, frames are retained on a chain and re-used where
520        possible. This sometimes gives as much as 30% improvement.
522    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
523        call.
525    14. As documented, (*COMMIT) is now confined to within a positive assertion.
527    15. It is now possible to link pcretest with libedit as an alternative to
528        libreadline.
530    16. (*COMMIT) control verb is now supported by the JIT compiler.
532    17. The Unicode data tables have been updated to Unicode 6.1.0.
534    18. Added --file-list option to pcregrep.
536    19. Added binary file support to pcregrep, including the -a, --binary-files,
537        -I, and --text options.
539    20. The madvise function is renamed for posix_madvise for QNX compatibility
540        reasons. Fixed by Giuseppe D'Angelo.
542    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
544    22. Changed the option for creating symbolic links for 16-bit man pages from
545        -s to -sf so that re-installing does not cause issues.
547    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
549    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
550        matches in certain environments (the workspace was not being correctly
551        retained). Also added to pcre_dfa_exec() a simple plausibility check on
552        some of the workspace data at the beginning of a restart.
554    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
555        was not doing so when it should - probably a typo introduced by SVN 528
556        (change 8.10/14).
558    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
559        \w+ when the character tables indicated that \x{c4} was a word character.
560        There were several related cases, all because the tests for doing a table
561        lookup were testing for characters less than 127 instead of 255.
563    27. If a pattern contains capturing parentheses that are not used in a match,
564        their slots in the ovector are set to -1. For those that are higher than
565        any matched groups, this happens at the end of processing. In the case when
566        there were back references that the ovector was too small to contain
567        (causing temporary malloc'd memory to be used during matching), and the
568        highest capturing number was not used, memory off the end of the ovector
569        was incorrectly being set to -1. (It was using the size of the temporary
570        memory instead of the true size.)
572    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
573        ovector size, it uses memory at the end of the block that it has got.
575    29. Check for an overlong MARK name and give an error at compile time. The
576        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
578    30. JIT compiler update.
580    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
581        Rill for the patch.
583    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
585    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
587    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
588        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
589        was enabled.
591    35. Improve JIT code generation for greedy plus quantifier.
593    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
594        1 to "aa" instead of to an empty string. The bug affected repeated groups
595        that could potentially match an empty string.
597    37. Optimizing single character iterators in JIT.
599    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
600        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
601        codepoints that are too big for the mode are faulted, and in a UTF mode,
602        disallowed codepoints are also faulted.
604    39. If PCRE was compiled with UTF support, in three places in the DFA
605        matcher there was code that should only have been obeyed in UTF mode, but
606        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
607        processing when bytes with values greater than 127 were present. In 16-bit
608        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
609        both cases the values are those that cannot be the first data item in a UTF
610        character. The three items that might have provoked this were recursions,
611        possessively repeated groups, and atomic groups.
613    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
614        and pcregrep, because some OS require shared objects to be explicitly
615        passed to ld, causing the link step to fail if they are not.
617    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
618        mode, patterns that started with \h* or \R* might be incorrectly matched.
621    Version 8.30 04-February-2012
622    -----------------------------
624    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
625        name is defined in ctype.h.
627    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
628        only in quite long subpatterns.
630    3.  Removed the function pcre_info(), which has been obsolete and deprecated
631        since it was replaced by pcre_fullinfo() in February 2000.
633    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
634        match a (*MARK), and the match failed at the start of the subject, a
635        reference to memory before the start of the subject could occur. This bug
636        was introduced by fix 17 of release 8.21.
638    5.  A reference to an unset group with zero minimum repetition was giving
639        totally wrong answers (in non-JavaScript-compatibility mode). For example,
640        /(another)?(\1?)test/ matched against "hello world test". This bug was
641        introduced in release 8.13.
643    6.  Add support for 16-bit character strings (a large amount of work involving
644        many changes and refactorings).
646    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
647        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
648        from a file.
650    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
651        rounding is not applied in this particular case).
653    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
654        if they appear, or are escaped, in patterns.
656    10. Get rid of a number of -Wunused-but-set-variable warnings.
658    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
659        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
660        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
661        also returns the mark "x". This bug applied to capturing parentheses,
662        non-capturing parentheses, and atomic parentheses. It also applied to some
663        assertions.
665    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
666        information out of configure.ac instead of relying on pcre.h.generic, which
667        is not stored in the repository.
669    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
670        -lreadline.
672    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
674    15. Applied Graycode's patch to put the top-level frame on the stack rather
675        than the heap when not using the stack for recursion. This gives a
676        performance improvement in many cases when recursion is not deep.
678    16. Experimental code added to "pcretest -C" to output the stack frame size.
681    Version 8.21 12-Dec-2011
682    ------------------------
684    1.  Updating the JIT compiler.
686    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
687        are added as well.
689    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
690        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
691        calling _pcre_jit_exec. Some extra comments are added.
693    4.  (*MARK) settings inside atomic groups that do not contain any capturing
694        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
695        was introduced by change 18 for 8.20.
697    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
698        ECMA-262 standard.
700    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
701        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
702        This bug was probably introduced by change 9 of 8.13.
704    7.  While fixing 6 above, I noticed that a number of other items were being
705        incorrectly rejected as "not fixed length". This arose partly because newer
706        opcodes had not been added to the fixed-length checking code. I have (a)
707        corrected the bug and added tests for these items, and (b) arranged for an
708        error to occur if an unknown opcode is encountered while checking for fixed
709        length instead of just assuming "not fixed length". The items that were
710        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
711        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
712        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
714    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
715        being incorrectly compiled and would have given unpredicatble results.
717    9.  A possessively repeated subpattern with minimum repeat count greater than
718        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
719        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
720        the first (A) could occur when it should not.
722    10. Add a cast and remove a redundant test from the code.
724    11. JIT should use pcre_malloc/pcre_free for allocation.
726    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
727        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
728        is anything other than /usr, -L is still shown).
730    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
732    14. Perl does not support \N without a following name in a [] class; PCRE now
733        also gives an error.
735    15. If a forward reference was repeated with an upper limit of around 2000,
736        it caused the error "internal error: overran compiling workspace". The
737        maximum number of forward references (including repeats) was limited by the
738        internal workspace, and dependent on the LINK_SIZE. The code has been
739        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
740        the default depends on LINK_SIZE. There is a new upper limit (for safety)
741        of around 200,000 forward references. While doing this, I also speeded up
742        the filling in of repeated forward references.
744    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
745        incorrectly expecting the subject to contain another "a" after the start.
747    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
748        in the match, the SKIP should be ignored. This was not happening; instead
749        the SKIP was being treated as NOMATCH. For patterns such as
750        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
751        tested.
753    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
754        now much more compatible with Perl, in particular in cases where the result
755        is a non-match for a non-anchored pattern. For example, if
756        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
757        "m", where previously it did not return a name. A side effect of this
758        change is that for partial matches, the last encountered mark name is
759        returned, as for non matches. A number of tests that were previously not
760        Perl-compatible have been moved into the Perl-compatible test files. The
761        refactoring has had the pleasing side effect of removing one argument from
762        the match() function, thus reducing its stack requirements.
764    19. If the /S+ option was used in pcretest to study a pattern using JIT,
765        subsequent uses of /S (without +) incorrectly behaved like /S+.
767    21. Retrieve executable code size support for the JIT compiler and fixing
768        some warnings.
770    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
771        not work when the shorter character appeared right at the end of the
772        subject string.
774    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
775        systems.
777    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
778        output it when the /M option is used in pcretest.
780    25. The CheckMan script was not being included in the distribution. Also, added
781        an explicit "perl" to run Perl scripts from the PrepareRelease script
782        because this is reportedly needed in Windows.
784    26. If study data was being save in a file and studying had not found a set of
785        "starts with" bytes for the pattern, the data written to the file (though
786        never used) was taken from uninitialized memory and so caused valgrind to
787        complain.
789    27. Updated RunTest.bat as provided by Sheri Pierce.
791    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
793    29. Computation of memory usage for the table of capturing group names was
794        giving an unnecessarily large value.
797    Version 8.20 21-Oct-2011
798    ------------------------
800    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
801        a POSIX class. After further experiments with Perl, which convinced me that
802        Perl has bugs and confusions, a closing square bracket is no longer allowed
803        in a POSIX name. This bug also affected patterns with classes that started
804        with full stops.
806    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
807        captured substring, but while checking the failing first alternative,
808        substring 1 is temporarily captured. If the output vector supplied to
809        pcre_exec() was not big enough for this capture, the yield of the function
810        was still zero ("insufficient space for captured substrings"). This cannot
811        be totally fixed without adding another stack variable, which seems a lot
812        of expense for a edge case. However, I have improved the situation in cases
813        such as /(a)(b)x|abc/ matched against "abc", where the return code
814        indicates that fewer than the maximum number of slots in the ovector have
815        been set.
817    3.  Related to (2) above: when there are more back references in a pattern than
818        slots in the output vector, pcre_exec() uses temporary memory during
819        matching, and copies in the captures as far as possible afterwards. It was
820        using the entire output vector, but this conflicts with the specification
821        that only 2/3 is used for passing back captured substrings. Now it uses
822        only the first 2/3, for compatibility. This is, of course, another edge
823        case.
825    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
826        main code base, and can be used by building with --enable-jit. When this is
827        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
828        runtime --no-jit option is given.
830    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
831        ovector, the return from the function was zero, implying that there were
832        other matches that did not fit. The correct "exactly full" value is now
833        returned.
835    6.  If a subpattern that was called recursively or as a subroutine contained
836        (*PRUNE) or any other control that caused it to give a non-standard return,
837        invalid errors such as "Error -26 (nested recursion at the same subject
838        position)" or even infinite loops could occur.
840    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
841        computing the minimum length on reaching *ACCEPT, and so ended up with the
842        wrong value of 1 rather than 0. Further investigation indicates that
843        computing a minimum subject length in the presence of *ACCEPT is difficult
844        (think back references, subroutine calls), and so I have changed the code
845        so that no minimum is registered for a pattern that contains *ACCEPT.
847    8.  If (*THEN) was present in the first (true) branch of a conditional group,
848        it was not handled as intended. [But see 16 below.]
850    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
851        Sheri Pierce.
853    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
854        the first byte in a match must be "a".
856    11. Change 17 for 8.13 increased the recursion depth for patterns like
857        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
858        pattern contains any instances of (*THEN). If it does not, the old
859        optimizations are restored. It would be nice to do this on a per-group
860        basis, but at the moment that is not feasible.
862    12. In some environments, the output of pcretest -C is CRLF terminated. This
863        broke RunTest's code that checks for the link size. A single white space
864        character after the value is now allowed for.
866    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
867        For "fr", it uses the Windows-specific input and output files.
869    14. If (*THEN) appeared in a group that was called recursively or as a
870        subroutine, it did not work as intended. [But see next item.]
872    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
873        pattern fragments (but not containing any | characters). If A and B are
874        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
875        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
876        D. In other words, Perl considers parentheses that do not contain any |
877        characters to be part of a surrounding alternative, whereas PCRE was
878        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
879        differently. PCRE now behaves in the same way as Perl, except in the case
880        of subroutine/recursion calls such as (?1) which have in any case always
881        been different (but PCRE had them first :-).
883    16. Related to 15 above: Perl does not treat the | in a conditional group as
884        creating alternatives. Such a group is treated in the same way as an
885        ordinary group without any | characters when processing (*THEN). PCRE has
886        been changed to match Perl's behaviour.
888    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
889        RunGrepTest script failed.
891    18. Change 22 for version 13 caused atomic groups to use more stack. This is
892        inevitable for groups that contain captures, but it can lead to a lot of
893        stack use in large patterns. The old behaviour has been restored for atomic
894        groups that do not contain any capturing parentheses.
896    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
897        suppress the check for a minimum subject length at run time. (If it was
898        given to pcre_exec() or pcre_dfa_exec() it did work.)
900    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
901        fail to work when decoding hex characters in data strings in EBCDIC
902        environments.
904    21. It appears that in at least one Mac OS environment, the isxdigit() function
905        is implemented as a macro that evaluates to its argument more than once,
906        contravening the C 90 Standard (I haven't checked a later standard). There
907        was an instance in pcretest which caused it to go wrong when processing
908        \x{...} escapes in subject strings. The has been rewritten to avoid using
909        things like p++ in the argument of isxdigit().
912    Version 8.13 16-Aug-2011
913    ------------------------
915    1.  The Unicode data tables have been updated to Unicode 6.0.0.
917    2.  Two minor typos in pcre_internal.h have been fixed.
919    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
920        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
921        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
923    4.  There were a number of related bugs in the code for matching backrefences
924        caselessly in UTF-8 mode when codes for the characters concerned were
925        different numbers of bytes. For example, U+023A and U+2C65 are an upper
926        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
927        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
928        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
929        2-byte code at the end of the subject (it thought there wasn't enough data
930        left).
932    5.  Comprehensive information about what went wrong is now returned by
933        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
934        as the output vector has at least 2 elements. The offset of the start of
935        the failing character and a reason code are placed in the vector.
937    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
938        now returned is for the first byte of the failing character, instead of the
939        last byte inspected. This is an incompatible change, but I hope it is small
940        enough not to be a problem. It makes the returned offset consistent with
941        pcre_exec() and pcre_dfa_exec().
943    7.  pcretest now gives a text phrase as well as the error number when
944        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
945        failure, the offset and reason code are output.
947    8.  When \R was used with a maximizing quantifier it failed to skip backwards
948        over a \r\n pair if the subsequent match failed. Instead, it just skipped
949        back over a single character (\n). This seems wrong (because it treated the
950        two characters as a single entity when going forwards), conflicts with the
951        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
952        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
953        has been changed.
955    9.  Some internal refactoring has changed the processing so that the handling
956        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
957        time (the PCRE_DOTALL option was changed this way some time ago: version
958        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
959        which was always a bit of a fudge. It also means that there is one less
960        argument for the match() function, which reduces its stack requirements
961        slightly. This change also fixes an incompatibility with Perl: the pattern
962        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
964    10. More internal refactoring has drastically reduced the number of recursive
965        calls to match() for possessively repeated groups such as (abc)++ when
966        using pcre_exec().
968    11. While implementing 10, a number of bugs in the handling of groups were
969        discovered and fixed:
971        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
972        (a|)*(?1) gave a compile-time internal error.
973        ((a|)+)+  did not notice that the outer group could match an empty string.
974        (^a|^)+   was not marked as anchored.
975        (.*a|.*)+ was not marked as matching at start or after a newline.
977    12. Yet more internal refactoring has removed another argument from the match()
978        function. Special calls to this function are now indicated by setting a
979        value in a variable in the "match data" data block.
981    13. Be more explicit in pcre_study() instead of relying on "default" for
982        opcodes that mean there is no starting character; this means that when new
983        ones are added and accidentally left out of pcre_study(), testing should
984        pick them up.
986    14. The -s option of pcretest has been documented for ages as being an old
987        synonym of -m (show memory usage). I have changed it to mean "force study
988        for every regex", that is, assume /S for every regex. This is similar to -i
989        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
990        using it. It makes it easier to run collections of tests with and without
991        study enabled, and thereby test pcre_study() more easily. All the standard
992        tests are now run with and without -s (but some patterns can be marked as
993        "never study" - see 20 below).
995    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
996        restoration of the capturing data to the outer values was not happening
997        correctly.
999    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1000        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1001        pattern had matched an empty string, and so incorrectly returned a no
1002        match.
1004    17. There was optimizing code for the last branch of non-capturing parentheses,
1005        and also for the obeyed branch of a conditional subexpression, which used
1006        tail recursion to cut down on stack usage. Unfortunately, now that there is
1007        the possibility of (*THEN) occurring in these branches, tail recursion is
1008        no longer possible because the return has to be checked for (*THEN). These
1009        two optimizations have therefore been removed. [But see 8.20/11 above.]
1011    18. If a pattern containing \R was studied, it was assumed that \R always
1012        matched two bytes, thus causing the minimum subject length to be
1013        incorrectly computed because \R can also match just one byte.
1015    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1016        was incorrectly computed.
1018    20. If /S is present twice on a test pattern in pcretest input, it now
1019        *disables* studying, thereby overriding the use of -s on the command line
1020        (see 14 above). This is necessary for one or two tests to keep the output
1021        identical in both cases.
1023    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1024        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1026    22. When an atomic group that contained a capturing parenthesis was
1027        successfully matched, but the branch in which it appeared failed, the
1028        capturing was not being forgotten if a higher numbered group was later
1029        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1030        group 1 to "a", when in fact it should be unset. This applied to multi-
1031        branched capturing and non-capturing groups, repeated or not, and also to
1032        positive assertions (capturing in negative assertions does not happen
1033        in PCRE) and also to nested atomic groups.
1035    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1036        subject after a captured substring, to make it easier to tell which of a
1037        number of identical substrings has been captured.
1039    24. The way atomic groups are processed by pcre_exec() has been changed so that
1040        if they are repeated, backtracking one repetition now resets captured
1041        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1042        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1043        "aaa". Previously, it would have been "a". As part of this code
1044        refactoring, the way recursive calls are handled has also been changed.
1046    25. If an assertion condition captured any substrings, they were not passed
1047        back unless some other capturing happened later. For example, if
1048        (?(?=(a))a) was matched against "a", no capturing was returned.
1050    26. When studying a pattern that contained subroutine calls or assertions,
1051        the code for finding the minimum length of a possible match was handling
1052        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1053        group 1 called group 2 while simultaneously a separate group 2 called group
1054        1). A stack overflow occurred in this case. I have fixed this by limiting
1055        the recursion depth to 10.
1057    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1058        Fortmann. This supports explicit test numbers on the command line, and has
1059        argument validation and error reporting.
1061    28. An instance of \X with an unlimited repeat could fail if at any point the
1062        first character it looked at was a mark character.
1064    29. Some minor code refactoring concerning Unicode properties and scripts
1065        should reduce the stack requirement of match() slightly.
1067    30. Added the '=' option to pcretest to check the setting of unused capturing
1068        slots at the end of the pattern, which are documented as being -1, but are
1069        not included in the return count.
1071    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1072        compiled something random. Now it gives a compile-time error (as does
1073        Perl).
1075    32. A *MARK encountered during the processing of a positive assertion is now
1076        recorded and passed back (compatible with Perl).
1078    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1079        had alternative anchored branches, the search for a second match in a line
1080        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1081        matched the line "0102" twice. The same bug affected patterns that started
1082        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1083        twice.
1085    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1086        does, and because of capturing effects, quantifying parenthesized
1087        assertions may at times be useful. Quantifiers are now allowed for
1088        parenthesized assertions.
1090    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1092    36. \g was being checked for fancy things in a character class, when it should
1093        just be a literal "g".
1095    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1096        appearance of a nested POSIX class supersedes an apparent external class.
1097        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1098        unescaped square brackets may also appear as part of class names. For
1099        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1100        more like Perl. (But see 8.20/1 above.)
1102    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1103        was because it thought it was \N{name}, which is not supported).
1105    39. Add minix to OS list not supporting the -S option in pcretest.
1107    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1108        cannot analyze patterns in sufficient detail to catch mutual recursions
1109        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1110        subgroup is called recursively as a subpattern for a second time at the
1111        same position in the subject string. In previous releases this might have
1112        been caught by the recursion limit, or it might have run out of stack.
1114    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1115        happen only once. PCRE was, however incorrectly giving a compile time error
1116        "recursive call could loop indefinitely" because it cannot analyze the
1117        pattern in sufficient detail. The compile time test no longer happens when
1118        PCRE is compiling a conditional subpattern, but actual runaway loops are
1119        now caught at runtime (see 40 above).
1121    42. It seems that Perl allows any characters other than a closing parenthesis
1122        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1123        has been changed to be the same.
1125    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1126        as not to get warnings when autogen.sh is called. Also changed
1127        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1129    44. To help people who use pcregrep to scan files containing exceedingly long
1130        lines, the following changes have been made:
1132        (a) The default value of the buffer size parameter has been increased from
1133            8K to 20K. (The actual buffer used is three times this size.)
1135        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1136            PCRE is built.
1138        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1139            to be set at run time.
1141        (d) Numerical values in pcregrep options can be followed by K or M, for
1142            example --buffer-size=50K.
1144        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1145            given and the return code is set to 2.
1147    45. Add a pointer to the latest mark to the callout data block.
1149    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1150        partial match of an empty string instead of no match. This was specific to
1151        the use of ".".
1153    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1154        complete match instead of a partial match. This bug was dependent on both
1155        the PCRE_UTF8 and PCRE_DOTALL options being set.
1157    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1158        starting byte set, because \b was not being ignored.
1161    Version 8.12 15-Jan-2011
1162    ------------------------
1164    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1165        checks for such things as part of the documentation building process.
1167    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1168        --match-limit and --recursion-limit options (added for 8.11). In
1169        particular, this made one of the standard tests fail. (The integer value
1170        went into the wrong half of a long int.)
1172    3.  If the --colour option was given to pcregrep with -v (invert match), it
1173        did strange things, either producing crazy output, or crashing. It should,
1174        of course, ignore a request for colour when reporting lines that do not
1175        match.
1177    4.  Another pcregrep bug caused similar problems if --colour was specified with
1178        -M (multiline) and the pattern match finished with a line ending.
1180    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1181        matched in multiline mode, the following line was shown as part of the
1182        match. This seems wrong, so I have changed it.
1184    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1185        the check for further matches in the same line (so they could be coloured)
1186        to overrun the end of the current line. If another match was found, it was
1187        incorrectly shown (and then shown again when found in the next line).
1189    7.  If pcregrep was compiled under Windows, there was a reference to the
1190        function pcregrep_exit() before it was defined. I am assuming this was
1191        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1192        reported by a user. I've moved the definition above the reference.
1195    Version 8.11 10-Dec-2010
1196    ------------------------
1198    1.  (*THEN) was not working properly if there were untried alternatives prior
1199        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1200        backtracked to try for "b" instead of moving to the next alternative branch
1201        at the same level (in this case, to look for "c"). The Perl documentation
1202        is clear that when (*THEN) is backtracked onto, it goes to the "next
1203        alternative in the innermost enclosing group".
1205    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1206        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1207        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1208        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1209        (*THEN).
1211    3.  If \s appeared in a character class, it removed the VT character from
1212        the class, even if it had been included by some previous item, for example
1213        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1214        of \s, but is part of the POSIX "space" class.)
1216    4.  A partial match never returns an empty string (because you can always
1217        match an empty string at the end of the subject); however the checking for
1218        an empty string was starting at the "start of match" point. This has been
1219        changed to the "earliest inspected character" point, because the returned
1220        data for a partial match starts at this character. This means that, for
1221        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1222        (previously it gave "no match").
1224    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1225        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1226        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1227        has an implication that the given string is incomplete (because a partial
1228        match is preferred over a full match). For this reason, these items now
1229        give a partial match in this situation. [Aside: previously, the one case
1230        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1231        match rather than a full match, which was wrong by the old rules, but is
1232        now correct.]
1234    6.  There was a bug in the handling of #-introduced comments, recognized when
1235        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1236        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1237        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1238        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1239        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1240        places in pcre_compile().
1242    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1243        comments when looking ahead for named forward references to subpatterns,
1244        the only newline sequence it recognized was NL. It now handles newlines
1245        according to the set newline convention.
1247    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1248        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1249        cater for a lack of strerror(). These oversights have been fixed.
1251    9.  Added --match-limit and --recursion-limit to pcregrep.
1253    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1255    11. When the -o option was used, pcregrep was setting a return code of 1, even
1256        when matches were found, and --line-buffered was not being honoured.
1258    12. Added an optional parentheses number to the -o and --only-matching options
1259        of pcregrep.
1261    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1262        can match an empty string. The code to do it in pcretest and pcredemo
1263        needed fixing:
1265        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1266            only one byte after an empty string match just before CRLF (this case
1267            just got forgotten; "any" and "anycrlf" were OK).
1269        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1270            mode when an empty string match preceded an ASCII character followed by
1271            a non-ASCII character. (The code for advancing by one character rather
1272            than one byte was nonsense.)
1274        (c) The pcredemo.c sample program did not have any code at all to handle
1275            the cases when CRLF is a valid newline sequence.
1277    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1278        as a starting offset was within the subject string. There is now a new
1279        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1280        negative or greater than the length of the string. In order to test this,
1281        pcretest is extended to allow the setting of negative starting offsets.
1283    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1284        starting offset points to the beginning of a UTF-8 character was
1285        unnecessarily clumsy. I tidied it up.
1287    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1288        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1290    17. Nobody had reported that the --include_dir option, which was added in
1291        release 7.7 should have been called --include-dir (hyphen, not underscore)
1292        for compatibility with GNU grep. I have changed it to --include-dir, but
1293        left --include_dir as an undocumented synonym, and the same for
1294        --exclude-dir, though that is not available in GNU grep, at least as of
1295        release 2.5.4.
1297    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1298        characters from a string of bytes) have been redefined so as not to use
1299        loops, in order to improve performance in some environments. At the same
1300        time, I abstracted some of the common code into auxiliary macros to save
1301        repetition (this should not affect the compiled code).
1303    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1304        compile-time error is now given if \c is not followed by an ASCII
1305        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1306        different, and any byte value is allowed.)
1308    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1309        START_OPTIMIZE option, which is now allowed at compile time - but just
1310        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1311        to pcregrep and other applications that have no direct access to PCRE
1312        options. The new /Y option in pcretest sets this option when calling
1313        pcre_compile().
1315    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1316        back references. Groups containing recursive back references were forced to
1317        be atomic by that change, but in the case of named groups, the amount of
1318        memory required was incorrectly computed, leading to "Failed: internal
1319        error: code overflow". This has been fixed.
1321    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1322        pcretest.c, to avoid build problems in some Borland environments.
1325    Version 8.10 25-Jun-2010
1326    ------------------------
1328    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1329        THEN.
1331    2.  (*ACCEPT) was not working when inside an atomic group.
1333    3.  Inside a character class, \B is treated as a literal by default, but
1334        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1335        causes the error). The code is unchanged, but I tidied the documentation.
1337    4.  Inside a character class, PCRE always treated \R and \X as literals,
1338        whereas Perl faults them if its -w option is set. I have changed PCRE so
1339        that it faults them when PCRE_EXTRA is set.
1341    5.  Added support for \N, which always matches any character other than
1342        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1344    6.  When compiling pcregrep with newer versions of gcc which may have
1345        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1346        declared with attribute warn_unused_result" were given. Just casting the
1347        result to (void) does not stop the warnings; a more elaborate fudge is
1348        needed. I've used a macro to implement this.
1350    7.  Minor change to pcretest.c to avoid a compiler warning.
1352    8.  Added four artifical Unicode properties to help with an option to make
1353        \s etc use properties (see next item). The new properties are: Xan
1354        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1356    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1357        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1358        this option. Modified pcretest to add /W to test this facility. Added
1359        REG_UCP to make it available via the POSIX interface.
1361    10. Added --line-buffered to pcregrep.
1363    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1364        studied, and the match started with a letter with a code point greater than
1365        127 whose first byte was different to the first byte of the other case of
1366        the letter, the other case of this starting letter was not recognized
1367        (#976).
1369    12. If a pattern that was studied started with a repeated Unicode property
1370        test, for example, \p{Nd}+, there was the theoretical possibility of
1371        setting up an incorrect bitmap of starting bytes, but fortunately it could
1372        not have actually happened in practice until change 8 above was made (it
1373        added property types that matched character-matching opcodes).
1375    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1376        possible starting bytes for non-anchored patterns.
1378    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1379        \R, and also a number of cases that involve Unicode properties, both
1380        explicit and implicit when PCRE_UCP is set.
1382    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1383        input, it could crash or give wrong results if characters with values
1384        greater than 0xc0 were present in the subject string. (Detail: it assumed
1385        UTF-8 input when processing these items.)
1387    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1388        size_t is 64-bit (#991).
1390    17. Added a check for running out of memory when PCRE is compiled with
1391        --disable-stack-for-recursion (#990).
1393    18. If the last data line in a file for pcretest does not have a newline on
1394        the end, a newline was missing in the output.
1396    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1397        less than 128) in its various bitmaps. However, there is a facility for
1398        generating tables according to the current locale when PCRE is compiled. It
1399        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1400        characters, are recognized by isspace() and therefore were getting set in
1401        these tables, and indeed these tables seem to approximate to ISO 8859. This
1402        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1403        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1404        which of course cannot start UTF-8 characters. I have changed the code so
1405        that only real ASCII characters (less than 128) and the correct starting
1406        bytes for UTF-8 encodings are set for characters greater than 127 when in
1407        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1408        altogether.)
1410    20. Added the /T option to pcretest so as to be able to run tests with non-
1411        standard character tables, thus making it possible to include the tests
1412        used for 19 above in the standard set of tests.
1414    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1415        reference to a subpattern the other side of a comment that contains an
1416        opening parenthesis caused either an internal compiling error, or a
1417        reference to the wrong subpattern.
1420    Version 8.02 19-Mar-2010
1421    ------------------------
1423    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1425    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1426        configured.
1428    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1429        original author of that file, following a query about its status.
1431    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1432        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1434    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1435        quantifier applied to a forward-referencing subroutine call, could compile
1436        incorrect code or give the error "internal error: previously-checked
1437        referenced subpattern not found".
1439    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1440        variables to point to external functions. For these systems, therefore,
1441        pcre_malloc etc. are now initialized to local functions that call the
1442        relevant global functions.
1444    7.  There were two entries missing in the vectors called coptable and poptable
1445        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1446        I've fixed the data, and added a kludgy way of testing at compile time that
1447        the lengths are correct (equal to the number of opcodes).
1449    8.  Following on from 7, I added a similar kludge to check the length of the
1450        eint vector in pcreposix.c.
1452    9.  Error texts for pcre_compile() are held as one long string to avoid too
1453        much relocation at load time. To find a text, the string is searched,
1454        counting zeros. There was no check for running off the end of the string,
1455        which could happen if a new error number was added without updating the
1456        string.
1458    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1460    11. \K was not working if it appeared in an atomic group or in a group that
1461        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1462        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1463        the assertion is positive, but not if it is negative.
1465    12. Change 11 fortuitously reduced the size of the stack frame used in the
1466        "match()" function of pcre_exec.c by one pointer. Forthcoming
1467        implementation of support for (*MARK) will need an extra pointer on the
1468        stack; I have reserved it now, so that the stack frame size does not
1469        decrease.
1471    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1472        item in branch that calls a recursion is a subroutine call - as in the
1473        second branch in the above example - was incorrectly given the compile-
1474        time error "recursive call could loop indefinitely" because pcre_compile()
1475        was not correctly checking the subroutine for matching a non-empty string.
1477    14. The checks for overrunning compiling workspace could trigger after an
1478        overrun had occurred. This is a "should never occur" error, but it can be
1479        triggered by pathological patterns such as hundreds of nested parentheses.
1480        The checks now trigger 100 bytes before the end of the workspace.
1482    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1485    Version 8.01 19-Jan-2010
1486    ------------------------
1488    1.  If a pattern contained a conditional subpattern with only one branch (in
1489        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1490        computed the wrong minimum data length (which is of course zero for such
1491        subpatterns). This could cause incorrect "no match" results.
1493    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1494        the pattern is reset in the first branch, pcre_compile() failed with
1495        "internal error: code overflow at offset...". This happened only when
1496        the reset was to the original external option setting. (An optimization
1497        abstracts leading options settings into an external setting, which was the
1498        cause of this.)
1500    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1501        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1502        assertion pattern did not match (meaning that the assertion was true), it
1503        was incorrectly treated as false if the SKIP had been reached during the
1504        matching. This also applied to assertions used as conditions.
1506    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1507        assertion subpattern, including such a pattern used as a condition,
1508        unpredictable results occurred, instead of the error return
1511    5.  The C++ GlobalReplace function was not working like Perl for the special
1512        situation when an empty string is matched. It now does the fancy magic
1513        stuff that is necessary.
1515    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1516        removed. (These were left over from very, very early versions of PCRE.)
1518    7.  Some cosmetic changes to the code to make life easier when compiling it
1519        as part of something else:
1521        (a) Change DEBUG to PCRE_DEBUG.
1523        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1524            called "current" as "current_branch", to prevent a collision with the
1525            Linux macro when compiled as a kernel module.
1527        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1528            prevent a collision with the Linux macro when compiled as a kernel
1529            module.
1531    8.  In pcre_compile() there are some checks for integer overflows that used to
1532        cast potentially large values to (double). This has been changed to that
1533        when building, a check for int64_t is made, and if it is found, it is used
1534        instead, thus avoiding the use of floating point arithmetic. (There is no
1535        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1536        double.
1538    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1539        2005 (difference between two addresses compared to an unsigned value).
1541    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1542        custom one, because of the following reported problem in Windows:
1544          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1545              under Win32.
1546          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1547              therefore missing the function definition.
1548          - The compiler thus generates a "C" signature for the test function.
1549          - The linker fails to find the "C" function.
1550          - PCRE fails to configure if asked to do so against libbz2.
1552    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1553        messages were output:
1555          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1556          rerunning libtoolize, to keep the correct libtool macros in-tree.
1557          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1559        I have done both of these things.
1561    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1562        most of the time, it *can* run out if it is given a pattern that contains a
1563        runaway infinite recursion. I updated the discussion in the pcrestack man
1564        page.
1566    13. Now that we have gone to the x.xx style of version numbers, the minor
1567        version may start with zero. Using 08 or 09 is a bad idea because users
1568        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1569        interpreted as invalid octal numbers. I've updated the previous comment in
1570        configure.ac, and also added a check that gives an error if 08 or 09 are
1571        used.
1573    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1574        causing partial matching to fail when the end of the subject matched \W
1575        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1577    15. There were some discrepancies between the declarations in pcre_internal.h
1578        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1579        their definitions. The declarations used "const uschar *" and the
1580        definitions used USPTR. Even though USPTR is normally defined as "const
1581        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1582        reported that: "This difference in casting confuses some C++ compilers, for
1583        example, SunCC recognizes above declarations as different functions and
1584        generates broken code for hbpcre." I have changed the declarations to use
1585        USPTR.
1587    16. GNU libtool is named differently on some systems. The autogen.sh script now
1588        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1589        (FreeBSD).
1591    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1592        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1593        comment: "Figure out how to create a longlong from a string: strtoll and
1594        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1595        instance, but it only takes 2 args instead of 3!"
1597    18. A subtle bug concerned with back references has been fixed by a change of
1598        specification, with a corresponding code fix. A pattern such as
1599        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1600        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1601        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1602        same bug. Such groups have to be quantified to be useful, or contained
1603        inside another quantified group. (If there's no repetition, the reference
1604        can never match.) The problem arises because, having left the group and
1605        moved on to the rest of the pattern, a later failure that backtracks into
1606        the group uses the captured value from the final iteration of the group
1607        rather than the correct earlier one. I have fixed this in PCRE by forcing
1608        any group that contains a reference to itself to be an atomic group; that
1609        is, there cannot be any backtracking into it once it has completed. This is
1610        similar to recursive and subroutine calls.
1613    Version 8.00 19-Oct-09
1614    ----------------------
1616    1.  The table for translating pcre_compile() error codes into POSIX error codes
1617        was out-of-date, and there was no check on the pcre_compile() error code
1618        being within the table. This could lead to an OK return being given in
1619        error.
1621    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1622        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1623        in a Windows environment.
1625    3.  The pcregrep --count option prints the count for each file even when it is
1626        zero, as does GNU grep. However, pcregrep was also printing all files when
1627        --files-with-matches was added. Now, when both options are given, it prints
1628        counts only for those files that have at least one match. (GNU grep just
1629        prints the file name in this circumstance, but including the count seems
1630        more useful - otherwise, why use --count?) Also ensured that the
1631        combination -clh just lists non-zero counts, with no names.
1633    4.  The long form of the pcregrep -F option was incorrectly implemented as
1634        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1635        but it seems right to fix it, and I didn't think it was worth preserving
1636        the old behaviour.
1638    5.  The command line items --regex=pattern and --regexp=pattern were not
1639        recognized by pcregrep, which required --regex pattern or --regexp pattern
1640        (with a space rather than an '='). The man page documented the '=' forms,
1641        which are compatible with GNU grep; these now work.
1643    6.  No libpcreposix.pc file was created for pkg-config; there was just
1644        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1646    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1647        when UCP support is not needed, by modifying the Python script that
1648        generates it from Unicode data files. This should not matter if the module
1649        is correctly used as a library, but I received one complaint about 50K of
1650        unwanted data. My guess is that the person linked everything into his
1651        program rather than using a library. Anyway, it does no harm.
1653    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1654        was a minimum greater than 1 for a wide character in a possessive
1655        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1656        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1657        character. Chaos in the form of incorrect output or a compiling loop could
1658        result.
1660    9.  The restrictions on what a pattern can contain when partial matching is
1661        requested for pcre_exec() have been removed. All patterns can now be
1662        partially matched by this function. In addition, if there are at least two
1663        slots in the offset vector, the offset of the earliest inspected character
1664        for the match and the offset of the end of the subject are set in them when
1665        PCRE_ERROR_PARTIAL is returned.
1667    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1668        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1669        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1670        and may be more useful for multi-segment matching.
1672    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1673        used to be given if ever the end of the subject was reached; now it is
1674        given only if matching could not proceed because another character was
1675        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1676        string "Z", which now yields "no match" instead of "partial match". In the
1677        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1678        final character ended with (*FAIL).
1680    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1681        if the pattern had a "must contain" character that was already found in the
1682        earlier partial match, unless partial matching was again requested. For
1683        example, with the pattern /dog.(body)?/, the "must contain" character is
1684        "g". If the first part-match was for the string "dog", restarting with
1685        "sbody" failed. This bug has been fixed.
1687    13. The string returned by pcre_dfa_exec() after a partial match has been
1688        changed so that it starts at the first inspected character rather than the
1689        first character of the match. This makes a difference only if the pattern
1690        starts with a lookbehind assertion or \b or \B (\K is not supported by
1691        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1692        matching functions compatible, and I think it's the right thing to do.
1694    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1695        so that the demonstration program is easily available in environments where
1696        PCRE has not been installed from source.
1698    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1699        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1700        library.
1702    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1703        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1704        is not the first non-POSIX option to be added. Clearly some people find
1705        these options useful.
1707    17. If a caller to the POSIX matching function regexec() passes a non-zero
1708        value for nmatch with a NULL value for pmatch, the value of
1709        nmatch is forced to zero.
1711    18. RunGrepTest did not have a test for the availability of the -u option of
1712        the diff command, as RunTest does. It now checks in the same way as
1713        RunTest, and also checks for the -b option.
1715    19. If an odd number of negated classes containing just a single character
1716        interposed, within parentheses, between a forward reference to a named
1717        subpattern and the definition of the subpattern, compilation crashed with
1718        an internal error, complaining that it could not find the referenced
1719        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1720        [The bug was that it was starting one character too far in when skipping
1721        over the character class, thus treating the ] as data rather than
1722        terminating the class. This meant it could skip too much.]
1724    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1725        /g option in pcretest when the pattern contains \K, which makes it possible
1726        to have an empty string match not at the start, even when the pattern is
1727        anchored. Updated pcretest and pcredemo to use this option.
1729    21. If the maximum number of capturing subpatterns in a recursion was greater
1730        than the maximum at the outer level, the higher number was returned, but
1731        with unset values at the outer level. The correct (outer level) value is
1732        now given.
1734    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1735        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1736        make it do so. The string so far is captured, making this feature
1737        compatible with Perl.
1739    23. The tests have been re-organized, adding tests 11 and 12, to make it
1740        possible to check the Perl 5.10 features against Perl 5.10.
1742    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1743        pattern matches a fixed length string. PCRE did not allow this; now it
1744        does. Neither allows recursion.
1746    25. I finally figured out how to implement a request to provide the minimum
1747        length of subject string that was needed in order to match a given pattern.
1748        (It was back references and recursion that I had previously got hung up
1749        on.) This code has now been added to pcre_study(); it finds a lower bound
1750        to the length of subject needed. It is not necessarily the greatest lower
1751        bound, but using it to avoid searching strings that are too short does give
1752        some useful speed-ups. The value is available to calling programs via
1753        pcre_fullinfo().
1755    26. While implementing 25, I discovered to my embarrassment that pcretest had
1756        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1757        study optimizations had never been tested with that matching function.
1758        Oops. What is worse, even when it was passed study data, there was a bug in
1759        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1760        were also very few tests of studied patterns with pcre_dfa_exec().
1762    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1763        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1764        on the other side of the coin, they are no longer allowed to have different
1765        names, because these cannot be distinguished in PCRE, and this has caused
1766        confusion. (This is a difference from Perl.)
1768    28. When duplicate subpattern names are present (necessarily with different
1769        numbers, as required by 27 above), and a test is made by name in a
1770        conditional pattern, either for a subpattern having been matched, or for
1771        recursion in such a pattern, all the associated numbered subpatterns are
1772        tested, and the overall condition is true if the condition is true for any
1773        one of them. This is the way Perl works, and is also more like the way
1774        testing by number works.
1777    Version 7.9 11-Apr-09
1778    ---------------------
1780    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1781        (pcretest), all targets were linked against these libraries. This included
1782        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1783        libraries. This caused unwanted dependencies to be created. This problem
1784        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1785        pcretest is linked with readline.
1787    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1788        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1789        moved outside it again, because FALSE and TRUE are already defined in AIX,
1790        but BOOL is not.
1792    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1793        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1795    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1796        hyphens) following file names and line numbers when outputting matching
1797        lines. This is not true; no spaces are inserted. I have also clarified the
1798        wording for the --colour (or --color) option.
1800    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1801        was not coloured; this is different to GNU grep, so I have changed it to be
1802        the same.
1804    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1805        each matching line was coloured. Now it goes on to look for further matches
1806        of any of the test patterns, which is the same behaviour as GNU grep.
1808    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1809        doesn't make sense to accept an empty string match in pcregrep, so I have
1810        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1811        seems to be how GNU grep behaves. [But see later change 40 for release
1812        8.33.]
1814    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1815        start or after a newline", because the conditional assertion was not being
1816        correctly handled. The rule now is that both the assertion and what follows
1817        in the first alternative must satisfy the test.
1819    9.  If auto-callout was enabled in a pattern with a conditional group whose
1820        condition was an assertion, PCRE could crash during matching, both with
1821        pcre_exec() and pcre_dfa_exec().
1823    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1824        used for matching.
1826    11. Unicode property support in character classes was not working for
1827        characters (bytes) greater than 127 when not in UTF-8 mode.
1829    12. Added the -M command line option to pcretest.
1831    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1833    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1835    16. Added comments and documentation about mis-use of no_arg in the C++
1836        wrapper.
1838    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1839        from Martin Jerabek that uses macro names for all relevant character and
1840        string constants.
1842    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1843        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1844        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1845        these, but not everybody uses configure.
1847    19. A conditional group that had only one branch was not being correctly
1848        recognized as an item that could match an empty string. This meant that an
1849        enclosing group might also not be so recognized, causing infinite looping
1850        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1851        with the subject "ab", where knowledge that the repeated group can match
1852        nothing is needed in order to break the loop.
1854    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1855        exec(), but without supplying a callout function, matching went wrong.
1857    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1858        leak if the size of the offset vector was greater than 30. When the vector
1859        is smaller, the saved offsets during recursion go onto a local stack
1860        vector, but for larger vectors malloc() is used. It was failing to free
1861        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1862        error, in fact).
1864    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1865        heapframe that is used only when UTF-8 support is enabled. This caused no
1866        problem, but was untidy.
1868    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1869        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1870        included within another project.
1872    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1873        slightly modified by me:
1875          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1876              not building pcregrep.
1878          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1879              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1881    25. Forward references, both numeric and by name, in patterns that made use of
1882        duplicate group numbers, could behave incorrectly or give incorrect errors,
1883        because when scanning forward to find the reference group, PCRE was not
1884        taking into account the duplicate group numbers. A pattern such as
1885        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1887    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1888        the feature of a custom pointer more persuasive (as requested by a user).
1890    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1891        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1892        pre-defined.
1894    28. Added support for (*UTF8) at the start of a pattern.
1896    29. Arrange for flags added by the "release type" setting in CMake to be shown
1897        in the configuration summary.
1900    Version 7.8 05-Sep-08
1901  ---------------------  ---------------------
1903  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 1927  Version 8.0 02 Jul-08
1928  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
1929      pointers, in case they are 64-bit values.      pointers, in case they are 64-bit values.
1931  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
1932      test 2 if it fails.      test 2 if it fails.
1934  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,
1935      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
1936      allow users of MSVC to set it if necessary.      allow users of MSVC to set it if necessary.
1938  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
1939      the convenience functions in the pcre_get.c source file.      the convenience functions in the pcre_get.c source file.
1941  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
1942      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
1943      some environments:      some environments:
1945        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
1947      This potential security problem was recorded as CVE-2008-2371.      This potential security problem was recorded as CVE-2008-2371.
1949    12. For a pattern where the match had to start at the beginning or immediately
1950        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1951        pcre_dfa_exec() could read past the end of the passed subject if there was
1952        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1953        pcretest so that it places the subject at the end of its malloc-ed buffer.
1955    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1956        exec() might read past the end of the data buffer in UTF-8 mode.
1958    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1959        the data contained the byte 0x85 as part of a UTF-8 character within its
1960        first line. This applied both to normal and DFA matching.
1962    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1963        /^[^d]*?$/8 failed to match "abc".
1965    16. Added a missing copyright notice to pcrecpp_internal.h.
1967    17. Make it more clear in the documentation that values returned from
1968        pcre_exec() in ovector are byte offsets, not character counts.
1970    18. Tidied a few places to stop certain compilers from issuing warnings.
1972    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1973        supplied by Stefan Weber. I made a further small update for 7.8 because
1974        there is a change of source arrangements: the pcre_searchfuncs.c module is
1975        replaced by pcre_ucd.c.
1978  Version 7.7 07-May-08  Version 7.7 07-May-08
1979  ---------------------  ---------------------
# Line 128  Version 7.7 07-May-08 Line 2052  Version 7.7 07-May-08
2052      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2053      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2054      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2055      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2056      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2057      was subsequently set up correctly.)      was subsequently set up correctly.)

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