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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-07  Version 8.33 28-April-2013
5    --------------------------
7    1.  Added 'U' to some constants that are compared to unsigned integers, to
8        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
9        variables that are added to signed variables, to ensure the result is
10        signed and can be negated.
12    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
13        CMake config files.
15    3.  Revise the creation of config.h.generic so that all boolean macros are
16        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
17        overriding via -D on the command line possible.
19    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
20        to unsigned int is reported to make a quite noticeable speed difference in
21        a specific Windows environment. Testing on Linux did also appear to show
22        some benefit (and it is clearly not harmful). Also fixed the definition of
23        Xop which should be unsigned.
25    5.  Related to (4), changing the definition of the intermediate variable cc
26        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
27        improvements.
29    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
30        unnecessary spaces.
32    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
33        and later.
35    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
37    9.  Optimizing fast_forward_start_bits in JIT.
39    10. Adding experimental support for callouts in JIT, and fixing some
40        issues revealed during this work. Namely:
42        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
44        (b) Minimum length was not checked before the matching is started.
46    11. The value of capture_last that is passed to callouts was incorrect in some
47        cases when there was a capture on one path that was subsequently abandoned
48        after a backtrack. Also, the capture_last value is now reset after a
49        recursion, since all captures are also reset in this case.
51    12. The interpreter no longer returns the "too many substrings" error in the
52        case when an overflowing capture is in a branch that is subsequently
53        abandoned after a backtrack.
55    13. In the pathological case when an offset vector of size 2 is used, pcretest
56        now prints out the matched string after a yield of 0 or 1.
58    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
59        Only supported by the JIT compiler at the moment.
61    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
63    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
64        offset of the starting point of the matching process, provided the offsets
65        vector is large enough.
67    17. The \A escape now records a lookbehind value of 1, though its execution
68        does not actually inspect the previous character. This is to ensure that,
69        in partial multi-segment matching, at least one character from the old
70        segment is retained when a new segment is processed. Otherwise, if there
71        are no lookbehinds in the pattern, \A might match incorrectly at the start
72        of a new segment.
74    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
76    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
77        gives some modest performance improvement in 8-bit mode.
79    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
80        be expressed in certain programming languages using Universal Character
81        Names.
83    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
84        which points out that "non characters" are not "characters that may not
85        appear in Unicode strings" but rather "characters that are reserved for
86        internal use and have only local meaning".
88    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
89        there was a conditional group that depended on an assertion, if the
90        assertion was false, the callout that immediately followed the alternation
91        in the condition was skipped when pcre_exec() was used for matching.
93    23. Allow an explicit callout to be inserted before an assertion that is the
94        condition for a conditional group, for compatibility with automatic
95        callouts, which always insert a callout at this point.
97    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
98        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
100    25. (*PRUNE) is now supported by the JIT compiler.
102    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
104    27. Fix the case where there are two or more SKIPs with arguments that may be
105        ignored.
107    28. (*SKIP) is now supported by the JIT compiler.
109    29. (*THEN) is now supported by the JIT compiler.
111    30. Update RunTest with additional test selector options.
113    31. The way PCRE handles backtracking verbs has been changed in two ways.
115        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
116        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
117        backtracking. In some cases this makes it more Perl-compatible, but Perl's
118        rather obscure rules do not always do the same thing.
120        (2) Previously, backtracking verbs were confined within assertions. This is
121        no longer the case for positive assertions, except for (*ACCEPT). Again,
122        this sometimes improves Perl compatibility, and sometimes does not.
124    32. A number of tests that were in test 2 because Perl did things differently
125        have been moved to test 1, because either Perl or PCRE has changed, and
126        these tests are now compatible.
128    32. Control verbs are handled in the same way in JIT and interpreter.
130    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
131        contained a forward subroutine reference caused a compile error.
133    34. Auto-detect and optimize limited repetitions in JIT.
135    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
136        blocking (*UTF) etc.
138    36. In the interpreter, maximizing pattern repetitions for characters and
139        character types now use tail recursion, which reduces stack usage.
141    37. The value of the max lookbehind was not correctly preserved if a compiled
142        and saved regex was reloaded on a host of different endianness.
144    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
145        of the compiled pattern block, expand the flags field from 16 to 32 bits
146        because it was almost full.
148    39. Try madvise first before posix_madvise.
151    Version 8.32 30-November-2012
152    -----------------------------
154    1.  Improved JIT compiler optimizations for first character search and single
155        character iterators.
157    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
158        Patch by Daniel Richard G.
160    3.  Single character iterator optimizations in the JIT compiler.
162    4.  Improved JIT compiler optimizations for character ranges.
164    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
165        Reported by Giuseppe D'Angelo.
167    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
168        of a line, was being set incorrectly in cases where .* appeared inside
169        atomic brackets at the start of a pattern, or where there was a subsequent
170        *PRUNE or *SKIP.
172    7.  Improved instruction cache flush for POWER/PowerPC.
173        Patch by Daniel Richard G.
175    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
176        grep:
178        (a) There is now no limit to the number of patterns to be matched.
180        (b) An error is given if a pattern is too long.
182        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
183            are now supported.
185        (d) --exclude-from and --include-from (multiple use) have been added.
187        (e) Exclusions and inclusions now apply to all files and directories, not
188            just to those obtained from scanning a directory recursively.
190        (f) Multiple uses of -f and --file-list are now supported.
192        (g) In a Windows environment, the default for -d has been changed from
193            "read" (the GNU grep default) to "skip", because otherwise the presence
194            of a directory in the file list provokes an error.
196        (h) The documentation has been revised and clarified in places.
198    9.  Improve the matching speed of capturing brackets.
200    10. Changed the meaning of \X so that it now matches a Unicode extended
201        grapheme cluster.
203    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
204        out POSIX threads when JIT support is configured.
206    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
208    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
209        structure could go wrong in environments where size_t is not the same size
210        as int.
212    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
213        set.
215    15. The EBCDIC support had decayed; later updates to the code had included
216        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
217        general tidy up of EBCDIC-related issues, and the documentation was also
218        not quite right. There is now a test that can be run on ASCII systems to
219        check some of the EBCDIC-related things (but is it not a full test).
221    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
222        in a small tidy to the code.
224    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
226    18. If the --only-matching (-o) option in pcregrep is specified multiple
227        times, each one causes appropriate output. For example, -o1 -o2 outputs the
228        substrings matched by the 1st and 2nd capturing parentheses. A separating
229        string can be specified by --om-separator (default empty).
231    19. Improving the first n character searches.
233    20. Turn case lists for horizontal and vertical white space into macros so that
234        they are defined only once.
236    21. This set of changes together give more compatible Unicode case-folding
237        behaviour for characters that have more than one other case when UCP
238        support is available.
240        (a) The Unicode property table now has offsets into a new table of sets of
241            three or more characters that are case-equivalent. The MultiStage2.py
242            script that generates these tables (the pcre_ucd.c file) now scans
243            CaseFolding.txt instead of UnicodeData.txt for character case
244            information.
246        (b) The code for adding characters or ranges of characters to a character
247            class has been abstracted into a generalized function that also handles
248            case-independence. In UTF-mode with UCP support, this uses the new data
249            to handle characters with more than one other case.
251        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
252            whose other case is greater than 256 are now correctly matched
253            caselessly. Previously, the high codepoint matched the low one, but not
254            vice versa.
256        (d) The processing of \h, \H, \v, and \ in character classes now makes use
257            of the new class addition function, using character lists defined as
258            macros alongside the case definitions of 20 above.
260        (e) Caseless back references now work with characters that have more than
261            one other case.
263        (f) General caseless matching of characters with more than one other case
264            is supported.
266    22. Unicode character properties were updated from Unicode 6.2.0
268    23. Improved CMake support under Windows. Patch by Daniel Richard G.
270    24. Add support for 32-bit character strings, and UTF-32
272    25. Major JIT compiler update (code refactoring and bugfixing).
273        Experimental Sparc 32 support is added.
275    26. Applied a modified version of Daniel Richard G's patch to create
276        pcre.h.generic and config.h.generic by "make" instead of in the
277        PrepareRelease script.
279    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
280        pcre_compile.c when checking for a zero character.
282    28. Introducing a native interface for JIT. Through this interface, the compiled
283        machine code can be directly executed. The purpose of this interface is to
284        provide fast pattern matching, so several sanity checks are not performed.
285        However, feature tests are still performed. The new interface provides
286        1.4x speedup compared to the old one.
288    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
289        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
290        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
292    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
293        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
294        the "old" RFC 2279). Instead, it ended up passing a negative length to
295        pcre_exec().
297    31. Add support for GCC's visibility feature to hide internal functions.
299    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
300        "unknown -C option" after outputting 0 or 1.
302    33. There is now support for generating a code coverage report for the test
303        suite in environments where gcc is the compiler and lcov is installed. This
304        is mainly for the benefit of the developers.
306    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
307        unaddressable using valgrind annotations, allowing valgrind to detect
308        invalid memory accesses. This is mainly for the benefit of the developers.
310    25. (*UTF) can now be used to start a pattern in any of the three libraries.
312    26. Give configure error if --enable-cpp but no C++ compiler found.
315    Version 8.31 06-July-2012
316    -------------------------
318    1.  Fixing a wrong JIT test case and some compiler warnings.
320    2.  Removed a bashism from the RunTest script.
322    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
323        to unsigned type, result still unsigned" that was given by an MS compiler
324        on encountering the code "-sizeof(xxx)".
326    4.  Partial matching support is added to the JIT compiler.
328    5.  Fixed several bugs concerned with partial matching of items that consist
329        of more than one character:
331        (a) /^(..)\1/ did not partially match "aba" because checking references was
332            done on an "all or nothing" basis. This also applied to repeated
333            references.
335        (b) \R did not give a hard partial match if \r was found at the end of the
336            subject.
338        (c) \X did not give a hard partial match after matching one or more
339            characters at the end of the subject.
341        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
342            a partial match for the string "\r".
344        (e) When newline was set to CRLF, the metacharacter "." did not recognize
345            a partial match for a CR character at the end of the subject string.
347    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
348        running pcretest, the text "(JIT)" added to the output whenever JIT is
349        actually used to run the match.
351    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
352        or /S+[+] with a digit between 1 and 7.
354    8.  OP_NOT now supports any UTF character not just single-byte ones.
356    9.  (*MARK) control verb is now supported by the JIT compiler.
358    10. The command "./RunTest list" lists the available tests without actually
359        running any of them. (Because I keep forgetting what they all are.)
363    12. Applied a (slightly modified) user-supplied patch that improves performance
364        when the heap is used for recursion (compiled with --disable-stack-for-
365        recursion). Instead of malloc and free for each heap frame each time a
366        logical recursion happens, frames are retained on a chain and re-used where
367        possible. This sometimes gives as much as 30% improvement.
369    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
370        call.
372    14. As documented, (*COMMIT) is now confined to within a positive assertion.
374    15. It is now possible to link pcretest with libedit as an alternative to
375        libreadline.
377    16. (*COMMIT) control verb is now supported by the JIT compiler.
379    17. The Unicode data tables have been updated to Unicode 6.1.0.
381    18. Added --file-list option to pcregrep.
383    19. Added binary file support to pcregrep, including the -a, --binary-files,
384        -I, and --text options.
386    20. The madvise function is renamed for posix_madvise for QNX compatibility
387        reasons. Fixed by Giuseppe D'Angelo.
389    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
391    22. Changed the option for creating symbolic links for 16-bit man pages from
392        -s to -sf so that re-installing does not cause issues.
394    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
396    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
397        matches in certain environments (the workspace was not being correctly
398        retained). Also added to pcre_dfa_exec() a simple plausibility check on
399        some of the workspace data at the beginning of a restart.
401    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
402        was not doing so when it should - probably a typo introduced by SVN 528
403        (change 8.10/14).
405    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
406        \w+ when the character tables indicated that \x{c4} was a word character.
407        There were several related cases, all because the tests for doing a table
408        lookup were testing for characters less than 127 instead of 255.
410    27. If a pattern contains capturing parentheses that are not used in a match,
411        their slots in the ovector are set to -1. For those that are higher than
412        any matched groups, this happens at the end of processing. In the case when
413        there were back references that the ovector was too small to contain
414        (causing temporary malloc'd memory to be used during matching), and the
415        highest capturing number was not used, memory off the end of the ovector
416        was incorrectly being set to -1. (It was using the size of the temporary
417        memory instead of the true size.)
419    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
420        ovector size, it uses memory at the end of the block that it has got.
422    29. Check for an overlong MARK name and give an error at compile time. The
423        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
425    30. JIT compiler update.
427    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
428        Rill for the patch.
430    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
432    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
434    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
435        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
436        was enabled.
438    35. Improve JIT code generation for greedy plus quantifier.
440    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
441        1 to "aa" instead of to an empty string. The bug affected repeated groups
442        that could potentially match an empty string.
444    37. Optimizing single character iterators in JIT.
446    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
447        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
448        codepoints that are too big for the mode are faulted, and in a UTF mode,
449        disallowed codepoints are also faulted.
451    39. If PCRE was compiled with UTF support, in three places in the DFA
452        matcher there was code that should only have been obeyed in UTF mode, but
453        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
454        processing when bytes with values greater than 127 were present. In 16-bit
455        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
456        both cases the values are those that cannot be the first data item in a UTF
457        character. The three items that might have provoked this were recursions,
458        possessively repeated groups, and atomic groups.
460    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
461        and pcregrep, because some OS require shared objects to be explicitly
462        passed to ld, causing the link step to fail if they are not.
464    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
465        mode, patterns that started with \h* or \R* might be incorrectly matched.
468    Version 8.30 04-February-2012
469    -----------------------------
471    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
472        name is defined in ctype.h.
474    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
475        only in quite long subpatterns.
477    3.  Removed the function pcre_info(), which has been obsolete and deprecated
478        since it was replaced by pcre_fullinfo() in February 2000.
480    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
481        match a (*MARK), and the match failed at the start of the subject, a
482        reference to memory before the start of the subject could occur. This bug
483        was introduced by fix 17 of release 8.21.
485    5.  A reference to an unset group with zero minimum repetition was giving
486        totally wrong answers (in non-JavaScript-compatibility mode). For example,
487        /(another)?(\1?)test/ matched against "hello world test". This bug was
488        introduced in release 8.13.
490    6.  Add support for 16-bit character strings (a large amount of work involving
491        many changes and refactorings).
493    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
494        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
495        from a file.
497    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
498        rounding is not applied in this particular case).
500    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
501        if they appear, or are escaped, in patterns.
503    10. Get rid of a number of -Wunused-but-set-variable warnings.
505    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
506        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
507        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
508        also returns the mark "x". This bug applied to capturing parentheses,
509        non-capturing parentheses, and atomic parentheses. It also applied to some
510        assertions.
512    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
513        information out of configure.ac instead of relying on pcre.h.generic, which
514        is not stored in the repository.
516    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
517        -lreadline.
519    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
521    15. Applied Graycode's patch to put the top-level frame on the stack rather
522        than the heap when not using the stack for recursion. This gives a
523        performance improvement in many cases when recursion is not deep.
525    16. Experimental code added to "pcretest -C" to output the stack frame size.
528    Version 8.21 12-Dec-2011
529    ------------------------
531    1.  Updating the JIT compiler.
533    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
534        are added as well.
536    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
537        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
538        calling _pcre_jit_exec. Some extra comments are added.
540    4.  (*MARK) settings inside atomic groups that do not contain any capturing
541        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
542        was introduced by change 18 for 8.20.
544    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
545        ECMA-262 standard.
547    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
548        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
549        This bug was probably introduced by change 9 of 8.13.
551    7.  While fixing 6 above, I noticed that a number of other items were being
552        incorrectly rejected as "not fixed length". This arose partly because newer
553        opcodes had not been added to the fixed-length checking code. I have (a)
554        corrected the bug and added tests for these items, and (b) arranged for an
555        error to occur if an unknown opcode is encountered while checking for fixed
556        length instead of just assuming "not fixed length". The items that were
557        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
558        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
559        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
561    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
562        being incorrectly compiled and would have given unpredicatble results.
564    9.  A possessively repeated subpattern with minimum repeat count greater than
565        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
566        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
567        the first (A) could occur when it should not.
569    10. Add a cast and remove a redundant test from the code.
571    11. JIT should use pcre_malloc/pcre_free for allocation.
573    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
574        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
575        is anything other than /usr, -L is still shown).
577    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
579    14. Perl does not support \N without a following name in a [] class; PCRE now
580        also gives an error.
582    15. If a forward reference was repeated with an upper limit of around 2000,
583        it caused the error "internal error: overran compiling workspace". The
584        maximum number of forward references (including repeats) was limited by the
585        internal workspace, and dependent on the LINK_SIZE. The code has been
586        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
587        the default depends on LINK_SIZE. There is a new upper limit (for safety)
588        of around 200,000 forward references. While doing this, I also speeded up
589        the filling in of repeated forward references.
591    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
592        incorrectly expecting the subject to contain another "a" after the start.
594    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
595        in the match, the SKIP should be ignored. This was not happening; instead
596        the SKIP was being treated as NOMATCH. For patterns such as
597        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
598        tested.
600    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
601        now much more compatible with Perl, in particular in cases where the result
602        is a non-match for a non-anchored pattern. For example, if
603        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
604        "m", where previously it did not return a name. A side effect of this
605        change is that for partial matches, the last encountered mark name is
606        returned, as for non matches. A number of tests that were previously not
607        Perl-compatible have been moved into the Perl-compatible test files. The
608        refactoring has had the pleasing side effect of removing one argument from
609        the match() function, thus reducing its stack requirements.
611    19. If the /S+ option was used in pcretest to study a pattern using JIT,
612        subsequent uses of /S (without +) incorrectly behaved like /S+.
614    21. Retrieve executable code size support for the JIT compiler and fixing
615        some warnings.
617    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
618        not work when the shorter character appeared right at the end of the
619        subject string.
621    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
622        systems.
624    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
625        output it when the /M option is used in pcretest.
627    25. The CheckMan script was not being included in the distribution. Also, added
628        an explicit "perl" to run Perl scripts from the PrepareRelease script
629        because this is reportedly needed in Windows.
631    26. If study data was being save in a file and studying had not found a set of
632        "starts with" bytes for the pattern, the data written to the file (though
633        never used) was taken from uninitialized memory and so caused valgrind to
634        complain.
636    27. Updated RunTest.bat as provided by Sheri Pierce.
638    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
640    29. Computation of memory usage for the table of capturing group names was
641        giving an unnecessarily large value.
644    Version 8.20 21-Oct-2011
645    ------------------------
647    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
648        a POSIX class. After further experiments with Perl, which convinced me that
649        Perl has bugs and confusions, a closing square bracket is no longer allowed
650        in a POSIX name. This bug also affected patterns with classes that started
651        with full stops.
653    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
654        captured substring, but while checking the failing first alternative,
655        substring 1 is temporarily captured. If the output vector supplied to
656        pcre_exec() was not big enough for this capture, the yield of the function
657        was still zero ("insufficient space for captured substrings"). This cannot
658        be totally fixed without adding another stack variable, which seems a lot
659        of expense for a edge case. However, I have improved the situation in cases
660        such as /(a)(b)x|abc/ matched against "abc", where the return code
661        indicates that fewer than the maximum number of slots in the ovector have
662        been set.
664    3.  Related to (2) above: when there are more back references in a pattern than
665        slots in the output vector, pcre_exec() uses temporary memory during
666        matching, and copies in the captures as far as possible afterwards. It was
667        using the entire output vector, but this conflicts with the specification
668        that only 2/3 is used for passing back captured substrings. Now it uses
669        only the first 2/3, for compatibility. This is, of course, another edge
670        case.
672    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
673        main code base, and can be used by building with --enable-jit. When this is
674        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
675        runtime --no-jit option is given.
677    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
678        ovector, the return from the function was zero, implying that there were
679        other matches that did not fit. The correct "exactly full" value is now
680        returned.
682    6.  If a subpattern that was called recursively or as a subroutine contained
683        (*PRUNE) or any other control that caused it to give a non-standard return,
684        invalid errors such as "Error -26 (nested recursion at the same subject
685        position)" or even infinite loops could occur.
687    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
688        computing the minimum length on reaching *ACCEPT, and so ended up with the
689        wrong value of 1 rather than 0. Further investigation indicates that
690        computing a minimum subject length in the presence of *ACCEPT is difficult
691        (think back references, subroutine calls), and so I have changed the code
692        so that no minimum is registered for a pattern that contains *ACCEPT.
694    8.  If (*THEN) was present in the first (true) branch of a conditional group,
695        it was not handled as intended. [But see 16 below.]
697    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
698        Sheri Pierce.
700    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
701        the first byte in a match must be "a".
703    11. Change 17 for 8.13 increased the recursion depth for patterns like
704        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
705        pattern contains any instances of (*THEN). If it does not, the old
706        optimizations are restored. It would be nice to do this on a per-group
707        basis, but at the moment that is not feasible.
709    12. In some environments, the output of pcretest -C is CRLF terminated. This
710        broke RunTest's code that checks for the link size. A single white space
711        character after the value is now allowed for.
713    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
714        For "fr", it uses the Windows-specific input and output files.
716    14. If (*THEN) appeared in a group that was called recursively or as a
717        subroutine, it did not work as intended. [But see next item.]
719    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
720        pattern fragments (but not containing any | characters). If A and B are
721        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
722        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
723        D. In other words, Perl considers parentheses that do not contain any |
724        characters to be part of a surrounding alternative, whereas PCRE was
725        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
726        differently. PCRE now behaves in the same way as Perl, except in the case
727        of subroutine/recursion calls such as (?1) which have in any case always
728        been different (but PCRE had them first :-).
730    16. Related to 15 above: Perl does not treat the | in a conditional group as
731        creating alternatives. Such a group is treated in the same way as an
732        ordinary group without any | characters when processing (*THEN). PCRE has
733        been changed to match Perl's behaviour.
735    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
736        RunGrepTest script failed.
738    18. Change 22 for version 13 caused atomic groups to use more stack. This is
739        inevitable for groups that contain captures, but it can lead to a lot of
740        stack use in large patterns. The old behaviour has been restored for atomic
741        groups that do not contain any capturing parentheses.
743    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
744        suppress the check for a minimum subject length at run time. (If it was
745        given to pcre_exec() or pcre_dfa_exec() it did work.)
747    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
748        fail to work when decoding hex characters in data strings in EBCDIC
749        environments.
751    21. It appears that in at least one Mac OS environment, the isxdigit() function
752        is implemented as a macro that evaluates to its argument more than once,
753        contravening the C 90 Standard (I haven't checked a later standard). There
754        was an instance in pcretest which caused it to go wrong when processing
755        \x{...} escapes in subject strings. The has been rewritten to avoid using
756        things like p++ in the argument of isxdigit().
759    Version 8.13 16-Aug-2011
760    ------------------------
762    1.  The Unicode data tables have been updated to Unicode 6.0.0.
764    2.  Two minor typos in pcre_internal.h have been fixed.
766    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
767        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
768        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
770    4.  There were a number of related bugs in the code for matching backrefences
771        caselessly in UTF-8 mode when codes for the characters concerned were
772        different numbers of bytes. For example, U+023A and U+2C65 are an upper
773        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
774        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
775        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
776        2-byte code at the end of the subject (it thought there wasn't enough data
777        left).
779    5.  Comprehensive information about what went wrong is now returned by
780        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
781        as the output vector has at least 2 elements. The offset of the start of
782        the failing character and a reason code are placed in the vector.
784    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
785        now returned is for the first byte of the failing character, instead of the
786        last byte inspected. This is an incompatible change, but I hope it is small
787        enough not to be a problem. It makes the returned offset consistent with
788        pcre_exec() and pcre_dfa_exec().
790    7.  pcretest now gives a text phrase as well as the error number when
791        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
792        failure, the offset and reason code are output.
794    8.  When \R was used with a maximizing quantifier it failed to skip backwards
795        over a \r\n pair if the subsequent match failed. Instead, it just skipped
796        back over a single character (\n). This seems wrong (because it treated the
797        two characters as a single entity when going forwards), conflicts with the
798        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
799        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
800        has been changed.
802    9.  Some internal refactoring has changed the processing so that the handling
803        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
804        time (the PCRE_DOTALL option was changed this way some time ago: version
805        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
806        which was always a bit of a fudge. It also means that there is one less
807        argument for the match() function, which reduces its stack requirements
808        slightly. This change also fixes an incompatibility with Perl: the pattern
809        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
811    10. More internal refactoring has drastically reduced the number of recursive
812        calls to match() for possessively repeated groups such as (abc)++ when
813        using pcre_exec().
815    11. While implementing 10, a number of bugs in the handling of groups were
816        discovered and fixed:
818        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
819        (a|)*(?1) gave a compile-time internal error.
820        ((a|)+)+  did not notice that the outer group could match an empty string.
821        (^a|^)+   was not marked as anchored.
822        (.*a|.*)+ was not marked as matching at start or after a newline.
824    12. Yet more internal refactoring has removed another argument from the match()
825        function. Special calls to this function are now indicated by setting a
826        value in a variable in the "match data" data block.
828    13. Be more explicit in pcre_study() instead of relying on "default" for
829        opcodes that mean there is no starting character; this means that when new
830        ones are added and accidentally left out of pcre_study(), testing should
831        pick them up.
833    14. The -s option of pcretest has been documented for ages as being an old
834        synonym of -m (show memory usage). I have changed it to mean "force study
835        for every regex", that is, assume /S for every regex. This is similar to -i
836        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
837        using it. It makes it easier to run collections of tests with and without
838        study enabled, and thereby test pcre_study() more easily. All the standard
839        tests are now run with and without -s (but some patterns can be marked as
840        "never study" - see 20 below).
842    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
843        restoration of the capturing data to the outer values was not happening
844        correctly.
846    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
847        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
848        pattern had matched an empty string, and so incorrectly returned a no
849        match.
851    17. There was optimizing code for the last branch of non-capturing parentheses,
852        and also for the obeyed branch of a conditional subexpression, which used
853        tail recursion to cut down on stack usage. Unfortunately, now that there is
854        the possibility of (*THEN) occurring in these branches, tail recursion is
855        no longer possible because the return has to be checked for (*THEN). These
856        two optimizations have therefore been removed. [But see 8.20/11 above.]
858    18. If a pattern containing \R was studied, it was assumed that \R always
859        matched two bytes, thus causing the minimum subject length to be
860        incorrectly computed because \R can also match just one byte.
862    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
863        was incorrectly computed.
865    20. If /S is present twice on a test pattern in pcretest input, it now
866        *disables* studying, thereby overriding the use of -s on the command line
867        (see 14 above). This is necessary for one or two tests to keep the output
868        identical in both cases.
870    21. When (*ACCEPT) was used in an assertion that matched an empty string and
871        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
873    22. When an atomic group that contained a capturing parenthesis was
874        successfully matched, but the branch in which it appeared failed, the
875        capturing was not being forgotten if a higher numbered group was later
876        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
877        group 1 to "a", when in fact it should be unset. This applied to multi-
878        branched capturing and non-capturing groups, repeated or not, and also to
879        positive assertions (capturing in negative assertions does not happen
880        in PCRE) and also to nested atomic groups.
882    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
883        subject after a captured substring, to make it easier to tell which of a
884        number of identical substrings has been captured.
886    24. The way atomic groups are processed by pcre_exec() has been changed so that
887        if they are repeated, backtracking one repetition now resets captured
888        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
889        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
890        "aaa". Previously, it would have been "a". As part of this code
891        refactoring, the way recursive calls are handled has also been changed.
893    25. If an assertion condition captured any substrings, they were not passed
894        back unless some other capturing happened later. For example, if
895        (?(?=(a))a) was matched against "a", no capturing was returned.
897    26. When studying a pattern that contained subroutine calls or assertions,
898        the code for finding the minimum length of a possible match was handling
899        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
900        group 1 called group 2 while simultaneously a separate group 2 called group
901        1). A stack overflow occurred in this case. I have fixed this by limiting
902        the recursion depth to 10.
904    27. Updated RunTest.bat in the distribution to the version supplied by Tom
905        Fortmann. This supports explicit test numbers on the command line, and has
906        argument validation and error reporting.
908    28. An instance of \X with an unlimited repeat could fail if at any point the
909        first character it looked at was a mark character.
911    29. Some minor code refactoring concerning Unicode properties and scripts
912        should reduce the stack requirement of match() slightly.
914    30. Added the '=' option to pcretest to check the setting of unused capturing
915        slots at the end of the pattern, which are documented as being -1, but are
916        not included in the return count.
918    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
919        compiled something random. Now it gives a compile-time error (as does
920        Perl).
922    32. A *MARK encountered during the processing of a positive assertion is now
923        recorded and passed back (compatible with Perl).
925    33. If --only-matching or --colour was set on a pcregrep call whose pattern
926        had alternative anchored branches, the search for a second match in a line
927        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
928        matched the line "0102" twice. The same bug affected patterns that started
929        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
930        twice.
932    34. Previously, PCRE did not allow quantification of assertions. However, Perl
933        does, and because of capturing effects, quantifying parenthesized
934        assertions may at times be useful. Quantifiers are now allowed for
935        parenthesized assertions.
937    35. A minor code tidy in pcre_compile() when checking options for \R usage.
939    36. \g was being checked for fancy things in a character class, when it should
940        just be a literal "g".
942    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
943        appearance of a nested POSIX class supersedes an apparent external class.
944        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
945        unescaped square brackets may also appear as part of class names. For
946        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
947        more like Perl. (But see 8.20/1 above.)
949    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
950        was because it thought it was \N{name}, which is not supported).
952    39. Add minix to OS list not supporting the -S option in pcretest.
954    40. PCRE tries to detect cases of infinite recursion at compile time, but it
955        cannot analyze patterns in sufficient detail to catch mutual recursions
956        such as ((?1))((?2)). There is now a runtime test that gives an error if a
957        subgroup is called recursively as a subpattern for a second time at the
958        same position in the subject string. In previous releases this might have
959        been caught by the recursion limit, or it might have run out of stack.
961    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
962        happen only once. PCRE was, however incorrectly giving a compile time error
963        "recursive call could loop indefinitely" because it cannot analyze the
964        pattern in sufficient detail. The compile time test no longer happens when
965        PCRE is compiling a conditional subpattern, but actual runaway loops are
966        now caught at runtime (see 40 above).
968    42. It seems that Perl allows any characters other than a closing parenthesis
969        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
970        has been changed to be the same.
972    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
973        as not to get warnings when autogen.sh is called. Also changed
974        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
976    44. To help people who use pcregrep to scan files containing exceedingly long
977        lines, the following changes have been made:
979        (a) The default value of the buffer size parameter has been increased from
980            8K to 20K. (The actual buffer used is three times this size.)
982        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
983            PCRE is built.
985        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
986            to be set at run time.
988        (d) Numerical values in pcregrep options can be followed by K or M, for
989            example --buffer-size=50K.
991        (e) If a line being scanned overflows pcregrep's buffer, an error is now
992            given and the return code is set to 2.
994    45. Add a pointer to the latest mark to the callout data block.
996    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
997        partial match of an empty string instead of no match. This was specific to
998        the use of ".".
1000    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1001        complete match instead of a partial match. This bug was dependent on both
1002        the PCRE_UTF8 and PCRE_DOTALL options being set.
1004    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1005        starting byte set, because \b was not being ignored.
1008    Version 8.12 15-Jan-2011
1009    ------------------------
1011    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1012        checks for such things as part of the documentation building process.
1014    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1015        --match-limit and --recursion-limit options (added for 8.11). In
1016        particular, this made one of the standard tests fail. (The integer value
1017        went into the wrong half of a long int.)
1019    3.  If the --colour option was given to pcregrep with -v (invert match), it
1020        did strange things, either producing crazy output, or crashing. It should,
1021        of course, ignore a request for colour when reporting lines that do not
1022        match.
1024    4.  Another pcregrep bug caused similar problems if --colour was specified with
1025        -M (multiline) and the pattern match finished with a line ending.
1027    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1028        matched in multiline mode, the following line was shown as part of the
1029        match. This seems wrong, so I have changed it.
1031    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1032        the check for further matches in the same line (so they could be coloured)
1033        to overrun the end of the current line. If another match was found, it was
1034        incorrectly shown (and then shown again when found in the next line).
1036    7.  If pcregrep was compiled under Windows, there was a reference to the
1037        function pcregrep_exit() before it was defined. I am assuming this was
1038        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1039        reported by a user. I've moved the definition above the reference.
1042    Version 8.11 10-Dec-2010
1043    ------------------------
1045    1.  (*THEN) was not working properly if there were untried alternatives prior
1046        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1047        backtracked to try for "b" instead of moving to the next alternative branch
1048        at the same level (in this case, to look for "c"). The Perl documentation
1049        is clear that when (*THEN) is backtracked onto, it goes to the "next
1050        alternative in the innermost enclosing group".
1052    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1053        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1054        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1055        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1056        (*THEN).
1058    3.  If \s appeared in a character class, it removed the VT character from
1059        the class, even if it had been included by some previous item, for example
1060        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1061        of \s, but is part of the POSIX "space" class.)
1063    4.  A partial match never returns an empty string (because you can always
1064        match an empty string at the end of the subject); however the checking for
1065        an empty string was starting at the "start of match" point. This has been
1066        changed to the "earliest inspected character" point, because the returned
1067        data for a partial match starts at this character. This means that, for
1068        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1069        (previously it gave "no match").
1071    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1072        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1073        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1074        has an implication that the given string is incomplete (because a partial
1075        match is preferred over a full match). For this reason, these items now
1076        give a partial match in this situation. [Aside: previously, the one case
1077        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1078        match rather than a full match, which was wrong by the old rules, but is
1079        now correct.]
1081    6.  There was a bug in the handling of #-introduced comments, recognized when
1082        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1083        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1084        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1085        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1086        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1087        places in pcre_compile().
1089    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1090        comments when looking ahead for named forward references to subpatterns,
1091        the only newline sequence it recognized was NL. It now handles newlines
1092        according to the set newline convention.
1094    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1095        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1096        cater for a lack of strerror(). These oversights have been fixed.
1098    9.  Added --match-limit and --recursion-limit to pcregrep.
1100    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1102    11. When the -o option was used, pcregrep was setting a return code of 1, even
1103        when matches were found, and --line-buffered was not being honoured.
1105    12. Added an optional parentheses number to the -o and --only-matching options
1106        of pcregrep.
1108    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1109        can match an empty string. The code to do it in pcretest and pcredemo
1110        needed fixing:
1112        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1113            only one byte after an empty string match just before CRLF (this case
1114            just got forgotten; "any" and "anycrlf" were OK).
1116        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1117            mode when an empty string match preceded an ASCII character followed by
1118            a non-ASCII character. (The code for advancing by one character rather
1119            than one byte was nonsense.)
1121        (c) The pcredemo.c sample program did not have any code at all to handle
1122            the cases when CRLF is a valid newline sequence.
1124    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1125        as a starting offset was within the subject string. There is now a new
1126        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1127        negative or greater than the length of the string. In order to test this,
1128        pcretest is extended to allow the setting of negative starting offsets.
1130    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1131        starting offset points to the beginning of a UTF-8 character was
1132        unnecessarily clumsy. I tidied it up.
1134    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1135        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1137    17. Nobody had reported that the --include_dir option, which was added in
1138        release 7.7 should have been called --include-dir (hyphen, not underscore)
1139        for compatibility with GNU grep. I have changed it to --include-dir, but
1140        left --include_dir as an undocumented synonym, and the same for
1141        --exclude-dir, though that is not available in GNU grep, at least as of
1142        release 2.5.4.
1144    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1145        characters from a string of bytes) have been redefined so as not to use
1146        loops, in order to improve performance in some environments. At the same
1147        time, I abstracted some of the common code into auxiliary macros to save
1148        repetition (this should not affect the compiled code).
1150    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1151        compile-time error is now given if \c is not followed by an ASCII
1152        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1153        different, and any byte value is allowed.)
1155    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1156        START_OPTIMIZE option, which is now allowed at compile time - but just
1157        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1158        to pcregrep and other applications that have no direct access to PCRE
1159        options. The new /Y option in pcretest sets this option when calling
1160        pcre_compile().
1162    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1163        back references. Groups containing recursive back references were forced to
1164        be atomic by that change, but in the case of named groups, the amount of
1165        memory required was incorrectly computed, leading to "Failed: internal
1166        error: code overflow". This has been fixed.
1168    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1169        pcretest.c, to avoid build problems in some Borland environments.
1172    Version 8.10 25-Jun-2010
1173    ------------------------
1175    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1176        THEN.
1178    2.  (*ACCEPT) was not working when inside an atomic group.
1180    3.  Inside a character class, \B is treated as a literal by default, but
1181        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1182        causes the error). The code is unchanged, but I tidied the documentation.
1184    4.  Inside a character class, PCRE always treated \R and \X as literals,
1185        whereas Perl faults them if its -w option is set. I have changed PCRE so
1186        that it faults them when PCRE_EXTRA is set.
1188    5.  Added support for \N, which always matches any character other than
1189        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1191    6.  When compiling pcregrep with newer versions of gcc which may have
1192        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1193        declared with attribute warn_unused_result" were given. Just casting the
1194        result to (void) does not stop the warnings; a more elaborate fudge is
1195        needed. I've used a macro to implement this.
1197    7.  Minor change to pcretest.c to avoid a compiler warning.
1199    8.  Added four artifical Unicode properties to help with an option to make
1200        \s etc use properties (see next item). The new properties are: Xan
1201        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1203    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1204        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1205        this option. Modified pcretest to add /W to test this facility. Added
1206        REG_UCP to make it available via the POSIX interface.
1208    10. Added --line-buffered to pcregrep.
1210    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1211        studied, and the match started with a letter with a code point greater than
1212        127 whose first byte was different to the first byte of the other case of
1213        the letter, the other case of this starting letter was not recognized
1214        (#976).
1216    12. If a pattern that was studied started with a repeated Unicode property
1217        test, for example, \p{Nd}+, there was the theoretical possibility of
1218        setting up an incorrect bitmap of starting bytes, but fortunately it could
1219        not have actually happened in practice until change 8 above was made (it
1220        added property types that matched character-matching opcodes).
1222    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1223        possible starting bytes for non-anchored patterns.
1225    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1226        \R, and also a number of cases that involve Unicode properties, both
1227        explicit and implicit when PCRE_UCP is set.
1229    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1230        input, it could crash or give wrong results if characters with values
1231        greater than 0xc0 were present in the subject string. (Detail: it assumed
1232        UTF-8 input when processing these items.)
1234    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1235        size_t is 64-bit (#991).
1237    17. Added a check for running out of memory when PCRE is compiled with
1238        --disable-stack-for-recursion (#990).
1240    18. If the last data line in a file for pcretest does not have a newline on
1241        the end, a newline was missing in the output.
1243    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1244        less than 128) in its various bitmaps. However, there is a facility for
1245        generating tables according to the current locale when PCRE is compiled. It
1246        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1247        characters, are recognized by isspace() and therefore were getting set in
1248        these tables, and indeed these tables seem to approximate to ISO 8859. This
1249        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1250        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1251        which of course cannot start UTF-8 characters. I have changed the code so
1252        that only real ASCII characters (less than 128) and the correct starting
1253        bytes for UTF-8 encodings are set for characters greater than 127 when in
1254        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1255        altogether.)
1257    20. Added the /T option to pcretest so as to be able to run tests with non-
1258        standard character tables, thus making it possible to include the tests
1259        used for 19 above in the standard set of tests.
1261    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1262        reference to a subpattern the other side of a comment that contains an
1263        opening parenthesis caused either an internal compiling error, or a
1264        reference to the wrong subpattern.
1267    Version 8.02 19-Mar-2010
1268    ------------------------
1270    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1272    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1273        configured.
1275    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1276        original author of that file, following a query about its status.
1278    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1279        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1281    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1282        quantifier applied to a forward-referencing subroutine call, could compile
1283        incorrect code or give the error "internal error: previously-checked
1284        referenced subpattern not found".
1286    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1287        variables to point to external functions. For these systems, therefore,
1288        pcre_malloc etc. are now initialized to local functions that call the
1289        relevant global functions.
1291    7.  There were two entries missing in the vectors called coptable and poptable
1292        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1293        I've fixed the data, and added a kludgy way of testing at compile time that
1294        the lengths are correct (equal to the number of opcodes).
1296    8.  Following on from 7, I added a similar kludge to check the length of the
1297        eint vector in pcreposix.c.
1299    9.  Error texts for pcre_compile() are held as one long string to avoid too
1300        much relocation at load time. To find a text, the string is searched,
1301        counting zeros. There was no check for running off the end of the string,
1302        which could happen if a new error number was added without updating the
1303        string.
1305    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1307    11. \K was not working if it appeared in an atomic group or in a group that
1308        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1309        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1310        the assertion is positive, but not if it is negative.
1312    12. Change 11 fortuitously reduced the size of the stack frame used in the
1313        "match()" function of pcre_exec.c by one pointer. Forthcoming
1314        implementation of support for (*MARK) will need an extra pointer on the
1315        stack; I have reserved it now, so that the stack frame size does not
1316        decrease.
1318    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1319        item in branch that calls a recursion is a subroutine call - as in the
1320        second branch in the above example - was incorrectly given the compile-
1321        time error "recursive call could loop indefinitely" because pcre_compile()
1322        was not correctly checking the subroutine for matching a non-empty string.
1324    14. The checks for overrunning compiling workspace could trigger after an
1325        overrun had occurred. This is a "should never occur" error, but it can be
1326        triggered by pathological patterns such as hundreds of nested parentheses.
1327        The checks now trigger 100 bytes before the end of the workspace.
1329    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1332    Version 8.01 19-Jan-2010
1333    ------------------------
1335    1.  If a pattern contained a conditional subpattern with only one branch (in
1336        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1337        computed the wrong minimum data length (which is of course zero for such
1338        subpatterns). This could cause incorrect "no match" results.
1340    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1341        the pattern is reset in the first branch, pcre_compile() failed with
1342        "internal error: code overflow at offset...". This happened only when
1343        the reset was to the original external option setting. (An optimization
1344        abstracts leading options settings into an external setting, which was the
1345        cause of this.)
1347    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1348        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1349        assertion pattern did not match (meaning that the assertion was true), it
1350        was incorrectly treated as false if the SKIP had been reached during the
1351        matching. This also applied to assertions used as conditions.
1353    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1354        assertion subpattern, including such a pattern used as a condition,
1355        unpredictable results occurred, instead of the error return
1358    5.  The C++ GlobalReplace function was not working like Perl for the special
1359        situation when an empty string is matched. It now does the fancy magic
1360        stuff that is necessary.
1362    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1363        removed. (These were left over from very, very early versions of PCRE.)
1365    7.  Some cosmetic changes to the code to make life easier when compiling it
1366        as part of something else:
1368        (a) Change DEBUG to PCRE_DEBUG.
1370        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1371            called "current" as "current_branch", to prevent a collision with the
1372            Linux macro when compiled as a kernel module.
1374        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1375            prevent a collision with the Linux macro when compiled as a kernel
1376            module.
1378    8.  In pcre_compile() there are some checks for integer overflows that used to
1379        cast potentially large values to (double). This has been changed to that
1380        when building, a check for int64_t is made, and if it is found, it is used
1381        instead, thus avoiding the use of floating point arithmetic. (There is no
1382        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1383        double.
1385    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1386        2005 (difference between two addresses compared to an unsigned value).
1388    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1389        custom one, because of the following reported problem in Windows:
1391          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1392              under Win32.
1393          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1394              therefore missing the function definition.
1395          - The compiler thus generates a "C" signature for the test function.
1396          - The linker fails to find the "C" function.
1397          - PCRE fails to configure if asked to do so against libbz2.
1399    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1400        messages were output:
1402          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1403          rerunning libtoolize, to keep the correct libtool macros in-tree.
1404          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1406        I have done both of these things.
1408    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1409        most of the time, it *can* run out if it is given a pattern that contains a
1410        runaway infinite recursion. I updated the discussion in the pcrestack man
1411        page.
1413    13. Now that we have gone to the x.xx style of version numbers, the minor
1414        version may start with zero. Using 08 or 09 is a bad idea because users
1415        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1416        interpreted as invalid octal numbers. I've updated the previous comment in
1417        configure.ac, and also added a check that gives an error if 08 or 09 are
1418        used.
1420    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1421        causing partial matching to fail when the end of the subject matched \W
1422        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1424    15. There were some discrepancies between the declarations in pcre_internal.h
1425        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1426        their definitions. The declarations used "const uschar *" and the
1427        definitions used USPTR. Even though USPTR is normally defined as "const
1428        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1429        reported that: "This difference in casting confuses some C++ compilers, for
1430        example, SunCC recognizes above declarations as different functions and
1431        generates broken code for hbpcre." I have changed the declarations to use
1432        USPTR.
1434    16. GNU libtool is named differently on some systems. The autogen.sh script now
1435        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1436        (FreeBSD).
1438    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1439        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1440        comment: "Figure out how to create a longlong from a string: strtoll and
1441        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1442        instance, but it only takes 2 args instead of 3!"
1444    18. A subtle bug concerned with back references has been fixed by a change of
1445        specification, with a corresponding code fix. A pattern such as
1446        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1447        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1448        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1449        same bug. Such groups have to be quantified to be useful, or contained
1450        inside another quantified group. (If there's no repetition, the reference
1451        can never match.) The problem arises because, having left the group and
1452        moved on to the rest of the pattern, a later failure that backtracks into
1453        the group uses the captured value from the final iteration of the group
1454        rather than the correct earlier one. I have fixed this in PCRE by forcing
1455        any group that contains a reference to itself to be an atomic group; that
1456        is, there cannot be any backtracking into it once it has completed. This is
1457        similar to recursive and subroutine calls.
1460    Version 8.00 19-Oct-09
1461    ----------------------
1463    1.  The table for translating pcre_compile() error codes into POSIX error codes
1464        was out-of-date, and there was no check on the pcre_compile() error code
1465        being within the table. This could lead to an OK return being given in
1466        error.
1468    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1469        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1470        in a Windows environment.
1472    3.  The pcregrep --count option prints the count for each file even when it is
1473        zero, as does GNU grep. However, pcregrep was also printing all files when
1474        --files-with-matches was added. Now, when both options are given, it prints
1475        counts only for those files that have at least one match. (GNU grep just
1476        prints the file name in this circumstance, but including the count seems
1477        more useful - otherwise, why use --count?) Also ensured that the
1478        combination -clh just lists non-zero counts, with no names.
1480    4.  The long form of the pcregrep -F option was incorrectly implemented as
1481        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1482        but it seems right to fix it, and I didn't think it was worth preserving
1483        the old behaviour.
1485    5.  The command line items --regex=pattern and --regexp=pattern were not
1486        recognized by pcregrep, which required --regex pattern or --regexp pattern
1487        (with a space rather than an '='). The man page documented the '=' forms,
1488        which are compatible with GNU grep; these now work.
1490    6.  No libpcreposix.pc file was created for pkg-config; there was just
1491        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1493    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1494        when UCP support is not needed, by modifying the Python script that
1495        generates it from Unicode data files. This should not matter if the module
1496        is correctly used as a library, but I received one complaint about 50K of
1497        unwanted data. My guess is that the person linked everything into his
1498        program rather than using a library. Anyway, it does no harm.
1500    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1501        was a minimum greater than 1 for a wide character in a possessive
1502        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1503        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1504        character. Chaos in the form of incorrect output or a compiling loop could
1505        result.
1507    9.  The restrictions on what a pattern can contain when partial matching is
1508        requested for pcre_exec() have been removed. All patterns can now be
1509        partially matched by this function. In addition, if there are at least two
1510        slots in the offset vector, the offset of the earliest inspected character
1511        for the match and the offset of the end of the subject are set in them when
1512        PCRE_ERROR_PARTIAL is returned.
1514    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1515        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1516        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1517        and may be more useful for multi-segment matching.
1519    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1520        used to be given if ever the end of the subject was reached; now it is
1521        given only if matching could not proceed because another character was
1522        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1523        string "Z", which now yields "no match" instead of "partial match". In the
1524        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1525        final character ended with (*FAIL).
1527    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1528        if the pattern had a "must contain" character that was already found in the
1529        earlier partial match, unless partial matching was again requested. For
1530        example, with the pattern /dog.(body)?/, the "must contain" character is
1531        "g". If the first part-match was for the string "dog", restarting with
1532        "sbody" failed. This bug has been fixed.
1534    13. The string returned by pcre_dfa_exec() after a partial match has been
1535        changed so that it starts at the first inspected character rather than the
1536        first character of the match. This makes a difference only if the pattern
1537        starts with a lookbehind assertion or \b or \B (\K is not supported by
1538        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1539        matching functions compatible, and I think it's the right thing to do.
1541    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1542        so that the demonstration program is easily available in environments where
1543        PCRE has not been installed from source.
1545    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1546        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1547        library.
1549    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1550        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1551        is not the first non-POSIX option to be added. Clearly some people find
1552        these options useful.
1554    17. If a caller to the POSIX matching function regexec() passes a non-zero
1555        value for nmatch with a NULL value for pmatch, the value of
1556        nmatch is forced to zero.
1558    18. RunGrepTest did not have a test for the availability of the -u option of
1559        the diff command, as RunTest does. It now checks in the same way as
1560        RunTest, and also checks for the -b option.
1562    19. If an odd number of negated classes containing just a single character
1563        interposed, within parentheses, between a forward reference to a named
1564        subpattern and the definition of the subpattern, compilation crashed with
1565        an internal error, complaining that it could not find the referenced
1566        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1567        [The bug was that it was starting one character too far in when skipping
1568        over the character class, thus treating the ] as data rather than
1569        terminating the class. This meant it could skip too much.]
1571    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1572        /g option in pcretest when the pattern contains \K, which makes it possible
1573        to have an empty string match not at the start, even when the pattern is
1574        anchored. Updated pcretest and pcredemo to use this option.
1576    21. If the maximum number of capturing subpatterns in a recursion was greater
1577        than the maximum at the outer level, the higher number was returned, but
1578        with unset values at the outer level. The correct (outer level) value is
1579        now given.
1581    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1582        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1583        make it do so. The string so far is captured, making this feature
1584        compatible with Perl.
1586    23. The tests have been re-organized, adding tests 11 and 12, to make it
1587        possible to check the Perl 5.10 features against Perl 5.10.
1589    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1590        pattern matches a fixed length string. PCRE did not allow this; now it
1591        does. Neither allows recursion.
1593    25. I finally figured out how to implement a request to provide the minimum
1594        length of subject string that was needed in order to match a given pattern.
1595        (It was back references and recursion that I had previously got hung up
1596        on.) This code has now been added to pcre_study(); it finds a lower bound
1597        to the length of subject needed. It is not necessarily the greatest lower
1598        bound, but using it to avoid searching strings that are too short does give
1599        some useful speed-ups. The value is available to calling programs via
1600        pcre_fullinfo().
1602    26. While implementing 25, I discovered to my embarrassment that pcretest had
1603        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1604        study optimizations had never been tested with that matching function.
1605        Oops. What is worse, even when it was passed study data, there was a bug in
1606        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1607        were also very few tests of studied patterns with pcre_dfa_exec().
1609    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1610        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1611        on the other side of the coin, they are no longer allowed to have different
1612        names, because these cannot be distinguished in PCRE, and this has caused
1613        confusion. (This is a difference from Perl.)
1615    28. When duplicate subpattern names are present (necessarily with different
1616        numbers, as required by 27 above), and a test is made by name in a
1617        conditional pattern, either for a subpattern having been matched, or for
1618        recursion in such a pattern, all the associated numbered subpatterns are
1619        tested, and the overall condition is true if the condition is true for any
1620        one of them. This is the way Perl works, and is also more like the way
1621        testing by number works.
1624    Version 7.9 11-Apr-09
1625    ---------------------
1627    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1628        (pcretest), all targets were linked against these libraries. This included
1629        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1630        libraries. This caused unwanted dependencies to be created. This problem
1631        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1632        pcretest is linked with readline.
1634    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1635        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1636        moved outside it again, because FALSE and TRUE are already defined in AIX,
1637        but BOOL is not.
1639    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1640        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1642    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1643        hyphens) following file names and line numbers when outputting matching
1644        lines. This is not true; no spaces are inserted. I have also clarified the
1645        wording for the --colour (or --color) option.
1647    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1648        was not coloured; this is different to GNU grep, so I have changed it to be
1649        the same.
1651    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1652        each matching line was coloured. Now it goes on to look for further matches
1653        of any of the test patterns, which is the same behaviour as GNU grep.
1655    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1656        doesn't make sense to accept an empty string match in pcregrep, so I have
1657        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1658        seems to be how GNU grep behaves.
1660    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1661        start or after a newline", because the conditional assertion was not being
1662        correctly handled. The rule now is that both the assertion and what follows
1663        in the first alternative must satisfy the test.
1665    9.  If auto-callout was enabled in a pattern with a conditional group whose
1666        condition was an assertion, PCRE could crash during matching, both with
1667        pcre_exec() and pcre_dfa_exec().
1669    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1670        used for matching.
1672    11. Unicode property support in character classes was not working for
1673        characters (bytes) greater than 127 when not in UTF-8 mode.
1675    12. Added the -M command line option to pcretest.
1677    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1679    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1681    16. Added comments and documentation about mis-use of no_arg in the C++
1682        wrapper.
1684    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1685        from Martin Jerabek that uses macro names for all relevant character and
1686        string constants.
1688    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1689        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1690        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1691        these, but not everybody uses configure.
1693    19. A conditional group that had only one branch was not being correctly
1694        recognized as an item that could match an empty string. This meant that an
1695        enclosing group might also not be so recognized, causing infinite looping
1696        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1697        with the subject "ab", where knowledge that the repeated group can match
1698        nothing is needed in order to break the loop.
1700    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1701        exec(), but without supplying a callout function, matching went wrong.
1703    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1704        leak if the size of the offset vector was greater than 30. When the vector
1705        is smaller, the saved offsets during recursion go onto a local stack
1706        vector, but for larger vectors malloc() is used. It was failing to free
1707        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1708        error, in fact).
1710    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1711        heapframe that is used only when UTF-8 support is enabled. This caused no
1712        problem, but was untidy.
1714    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1715        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1716        included within another project.
1718    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1719        slightly modified by me:
1721          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1722              not building pcregrep.
1724          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1725              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1727    25. Forward references, both numeric and by name, in patterns that made use of
1728        duplicate group numbers, could behave incorrectly or give incorrect errors,
1729        because when scanning forward to find the reference group, PCRE was not
1730        taking into account the duplicate group numbers. A pattern such as
1731        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1733    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1734        the feature of a custom pointer more persuasive (as requested by a user).
1736    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1737        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1738        pre-defined.
1740    28. Added support for (*UTF8) at the start of a pattern.
1742    29. Arrange for flags added by the "release type" setting in CMake to be shown
1743        in the configuration summary.
1746    Version 7.8 05-Sep-08
1747    ---------------------
1749    1.  Replaced UCP searching code with optimized version as implemented for Ad
1750        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1751        stage table and inline lookup instead of a function, giving speed ups of 2
1752        to 5 times on some simple patterns that I tested. Permission was given to
1753        distribute the MultiStage2.py script that generates the tables (it's not in
1754        the tarball, but is in the Subversion repository).
1756    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1757        scripts.
1759    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1760        a group with a zero qualifier. The result of the study could be incorrect,
1761        or the function might crash, depending on the pattern.
1763    4.  Caseless matching was not working for non-ASCII characters in back
1764        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1765        It now works when Unicode Property Support is available.
1767    5.  In pcretest, an escape such as \x{de} in the data was always generating
1768        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1769        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1770        truncation.
1772    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1774    7.  Added two (int) casts to pcregrep when printing the difference of two
1775        pointers, in case they are 64-bit values.
1777    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1778        test 2 if it fails.
1780    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1781        and a #define of that name to empty if it is not externally set. This is to
1782        allow users of MSVC to set it if necessary.
1784    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1785        the convenience functions in the pcre_get.c source file.
1787    11. An option change at the start of a pattern that had top-level alternatives
1788        could cause overwriting and/or a crash. This command provoked a crash in
1789        some environments:
1791          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1793        This potential security problem was recorded as CVE-2008-2371.
1795    12. For a pattern where the match had to start at the beginning or immediately
1796        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1797        pcre_dfa_exec() could read past the end of the passed subject if there was
1798        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1799        pcretest so that it places the subject at the end of its malloc-ed buffer.
1801    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1802        exec() might read past the end of the data buffer in UTF-8 mode.
1804    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1805        the data contained the byte 0x85 as part of a UTF-8 character within its
1806        first line. This applied both to normal and DFA matching.
1808    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1809        /^[^d]*?$/8 failed to match "abc".
1811    16. Added a missing copyright notice to pcrecpp_internal.h.
1813    17. Make it more clear in the documentation that values returned from
1814        pcre_exec() in ovector are byte offsets, not character counts.
1816    18. Tidied a few places to stop certain compilers from issuing warnings.
1818    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1819        supplied by Stefan Weber. I made a further small update for 7.8 because
1820        there is a change of source arrangements: the pcre_searchfuncs.c module is
1821        replaced by pcre_ucd.c.
1824    Version 7.7 07-May-08
1825    ---------------------
1827    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1828        a string to a long long, pretend we don't even have a long long." This is
1829        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1831    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1832        pre-7.6 versions, which defined a global no_arg variable instead of putting
1833        it in the RE class. (See also #8 below.)
1835    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1836        Lopes.
1838    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1840        (1) The include/exclude patterns were being applied to the whole pathnames
1841            of files, instead of just to the final components.
1843        (2) If there was more than one level of directory, the subdirectories were
1844            skipped unless they satisfied the include/exclude conditions. This is
1845            inconsistent with GNU grep (and could even be seen as contrary to the
1846            pcregrep specification - which I improved to make it absolutely clear).
1847            The action now is always to scan all levels of directory, and just
1848            apply the include/exclude patterns to regular files.
1850    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1851        --exclude_dir in the tests to avoid scanning .svn directories.
1853    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1854        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1855        doesn't support NULs in patterns.
1857    7.  Added some missing "const"s to declarations of static tables in
1858        pcre_compile.c and pcre_dfa_exec.c.
1860    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1861        caused by fix #2  above. (Subsequently also a second patch to fix the
1862        first patch. And a third patch - this was a messy problem.)
1864    9.  Applied Craig's patch to remove the use of push_back().
1866    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1867        matching function regexec().
1869    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1870        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1871        references. PCRE supports relative numbers with this syntax (I don't think
1872        Oniguruma does).
1874    12. Previously, a group with a zero repeat such as (...){0} was completely
1875        omitted from the compiled regex. However, this means that if the group
1876        was called as a subroutine from elsewhere in the pattern, things went wrong
1877        (an internal error was given). Such groups are now left in the compiled
1878        pattern, with a new opcode that causes them to be skipped at execution
1879        time.
1881    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1882        to the way PCRE behaves:
1884        (a) A lone ] character is dis-allowed (Perl treats it as data).
1886        (b) A back reference to an unmatched subpattern matches an empty string
1887            (Perl fails the current match path).
1889        (c) A data ] in a character class must be notated as \] because if the
1890            first data character in a class is ], it defines an empty class. (In
1891            Perl it is not possible to have an empty class.) The empty class []
1892            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1893            The negative empty class [^] matches any one character, independently
1894            of the DOTALL setting.
1896    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1897        non-existent subpattern following a character class starting with ']' and
1898        containing () gave an internal compiling error instead of "reference to
1899        non-existent subpattern". Fortunately, when the pattern did exist, the
1900        compiled code was correct. (When scanning forwards to check for the
1901        existencd of the subpattern, it was treating the data ']' as terminating
1902        the class, so got the count wrong. When actually compiling, the reference
1903        was subsequently set up correctly.)
1905    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1906        it was being rejected as not supported by pcre_dfa_exec(), even though
1907        other assertions are supported. I have made pcre_dfa_exec() support
1908        (*FAIL).
1910    16. The implementation of 13c above involved the invention of a new opcode,
1911        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1912        cannot be changed at match time, I realized I could make a small
1913        improvement to matching performance by compiling OP_ALLANY instead of
1914        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1915        on the OP_ANY path.
1917    17. Compiling pcretest on Windows with readline support failed without the
1918        following two fixes: (1) Make the unistd.h include conditional on
1919        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1921    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1922        ncurses library to be included for pcretest when ReadLine support is
1923        requested, but also to allow for it to be overridden. This patch came from
1924        Daniel Bergström.
1926    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1927        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1928        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1929        spotting this.
1932    Version 7.6 28-Jan-08
1933    ---------------------
1935    1.  A character class containing a very large number of characters with
1936        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1937        overflow.
1939    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1940        HAVE_LONG_LONG is not defined.
1942    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1943        bring them up to date and include new features. This patch includes:
1945        - Fixed PH's badly added libz and libbz2 support.
1946        - Fixed a problem with static linking.
1947        - Added pcredemo. [But later removed - see 7 below.]
1948        - Fixed dftables problem and added an option.
1949        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1950            HAVE_LONG_LONG.
1951        - Added readline support for pcretest.
1952        - Added an listing of the option settings after cmake has run.
1954    4.  A user submitted a patch to Makefile that makes it easy to create
1955        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1956        Makefile.am that cause it to include this special target, without
1957        affecting anything else. Note that the same mingw target plus all
1958        the other distribution libraries and programs are now supported
1959        when configuring with CMake (see 6 below) instead of with
1960        Configure/Make.
1962    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1963        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1964        exported in the Windows port". It has not yet been confirmed that the patch
1965        solves the problem, but it does no harm.
1967    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1968        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1969        with CMake, and also correct the comment about stack recursion.
1971    7.  Remove the automatic building of pcredemo from the ./configure system and
1972        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1973        of a program that users should build themselves after PCRE is installed, so
1974        building it automatically is not really right. What is more, it gave
1975        trouble in some build environments.
1977    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1980    Version 7.5 10-Jan-08
1981    ---------------------
1983    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1984        values in parens when parsing an RE using the C++ wrapper."
1986    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1987        Characters greater than 255 were excluded from the class instead of being
1988        included.
1990    3.  The same bug as (2) above applied to negated POSIX classes such as
1991        [:^space:].
1993    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1994        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1995        I have changed it.
1997    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1998        first named subpattern) and a construct such as (?&a) would reference the
1999        first named subpattern whose name started with "a" (in other words, the
2000        length check was missing). Both these problems are fixed. "Subpattern name
2001        expected" is now given for (?&) (a zero-length name), and this patch also
2002        makes it give the same error for \k'' (previously it complained that that
2003        was a reference to a non-existent subpattern).
2005    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
2006        this is right because (?- can be followed by option settings as well as by
2007        digits. I have, however, made the messages clearer.
2009    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2010        than the number used in the conditional) now cause a compile-time error.
2011        This is actually not compatible with Perl, which accepts such patterns, but
2012        treats the conditional as always being FALSE (as PCRE used to), but it
2013        seems to me that giving a diagnostic is better.
2015    8.  Change "alphameric" to the more common word "alphanumeric" in comments
2016        and messages.
2018    9.  Fix two occurrences of "backslash" in comments that should have been
2019        "backspace".
2021    10. Remove two redundant lines of code that can never be obeyed (their function
2022        was moved elsewhere).
2024    11. The program that makes PCRE's Unicode character property table had a bug
2025        which caused it to generate incorrect table entries for sequences of
2026        characters that have the same character type, but are in different scripts.
2027        It amalgamated them into a single range, with the script of the first of
2028        them. In other words, some characters were in the wrong script. There were
2029        thirteen such cases, affecting characters in the following ranges:
2031          U+002b0 - U+002c1
2032          U+0060c - U+0060d
2033          U+0061e - U+00612
2034          U+0064b - U+0065e
2035          U+0074d - U+0076d
2036          U+01800 - U+01805
2037          U+01d00 - U+01d77
2038          U+01d9b - U+01dbf
2039          U+0200b - U+0200f
2040          U+030fc - U+030fe
2041          U+03260 - U+0327f
2042          U+0fb46 - U+0fbb1
2043          U+10450 - U+1049d
2045    12. The -o option (show only the matching part of a line) for pcregrep was not
2046        compatible with GNU grep in that, if there was more than one match in a
2047        line, it showed only the first of them. It now behaves in the same way as
2048        GNU grep.
2050    13. If the -o and -v options were combined for pcregrep, it printed a blank
2051        line for every non-matching line. GNU grep prints nothing, and pcregrep now
2052        does the same. The return code can be used to tell if there were any
2053        non-matching lines.
2055    14. Added --file-offsets and --line-offsets to pcregrep.
2057    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2058        infinitely looping recursion. The bug was that positive lookaheads were not
2059        being skipped when checking for a possible empty match (negative lookaheads
2060        and both kinds of lookbehind were skipped).
2062    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2063        inclusion of <windows.h> to before rather than after the definition of
2064        INVALID_FILE_ATTRIBUTES (patch from David Byron).
2066    17. Specifying a possessive quantifier with a specific limit for a Unicode
2067        character property caused pcre_compile() to compile bad code, which led at
2068        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2069        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2070        caused the error; without that there was no problem.
2072    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2074    19. Added --enable-pcretest-libreadline.
2076    20. In pcrecpp.cc, the variable 'count' was incremented twice in
2077        RE::GlobalReplace(). As a result, the number of replacements returned was
2078        double what it should be. I removed one of the increments, but Craig sent a
2079        later patch that removed the other one (the right fix) and added unit tests
2080        that check the return values (which was not done before).
2082    21. Several CMake things:
2084        (1) Arranged that, when cmake is used on Unix, the libraries end up with
2085            the names libpcre and libpcreposix, not just pcre and pcreposix.
2087        (2) The above change means that pcretest and pcregrep are now correctly
2088            linked with the newly-built libraries, not previously installed ones.
2092    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2093        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2094        UTF-8 newline character). The key issue is that the pattern starts .*;
2095        this means that the match must be either at the beginning, or after a
2096        newline. The bug was in the code for advancing after a failed match and
2097        checking that the new position followed a newline. It was not taking
2098        account of UTF-8 characters correctly.
2100    23. PCRE was behaving differently from Perl in the way it recognized POSIX
2101        character classes. PCRE was not treating the sequence [:...:] as a
2102        character class unless the ... were all letters. Perl, however, seems to
2103        allow any characters between [: and :], though of course it rejects as
2104        unknown any "names" that contain non-letters, because all the known class
2105        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2106        for example, whereas PCRE did not - it did not recognize a POSIX character
2107        class. This seemed a bit dangerous, so the code has been changed to be
2108        closer to Perl. The behaviour is not identical to Perl, because PCRE will
2109        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2110        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2111        Perl does, and where it didn't before.
2113    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2114        Windows environments %n is disabled by default.
2117    Version 7.4 21-Sep-07
2118    ---------------------
2120    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
2121        means that a class such as [\s] counted as "explicit reference to CR or
2122        LF". That isn't really right - the whole point of the change was to try to
2123        help when there was an actual mention of one of the two characters. So now
2124        the change happens only if \r or \n (or a literal CR or LF) character is
2125        encountered.
2127    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
2128        of both had grown to the point where there were only 3 bits left.
2129        Fortunately, there was spare space in the data structure, and so I have
2130        moved the internal flags into a new 16-bit field to free up more option
2131        bits.
2133    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2134        but did not set the internal JCHANGED flag - either of these is enough to
2135        control the way the "get" function works - but the PCRE_INFO_JCHANGED
2136        facility is supposed to tell if (?J) was ever used, so now (?J) at the
2137        start sets both bits.
2139    4.  Added options (at build time, compile time, exec time) to change \R from
2140        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2142    5.  doc/pcresyntax.html was missing from the distribution.
2144    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2145        compatibility, even though it is no longer used.
2147    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2148        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2149        windows.h file is present (where different names are used). [This was
2150        reversed later after testing - see 16 below.]
2152    8.  Changed all #include <config.h> to #include "config.h". There were also
2153        some further <pcre.h> cases that I changed to "pcre.h".
2155    9.  When pcregrep was used with the --colour option, it missed the line ending
2156        sequence off the lines that it output.
2158    10. It was pointed out to me that arrays of string pointers cause lots of
2159        relocations when a shared library is dynamically loaded. A technique of
2160        using a single long string with a table of offsets can drastically reduce
2161        these. I have refactored PCRE in four places to do this. The result is
2162        dramatic:
2164          Originally:                          290
2165          After changing UCP table:            187
2166          After changing error message table:   43
2167          After changing table of "verbs"       36
2168          After changing table of Posix names   22
2170        Thanks to the folks working on Gregex for glib for this insight.
2172    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2173        unicode-properties was also set.
2175    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2177    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2178        checked only for CRLF.
2180    14. Added casts to pcretest.c to avoid compiler warnings.
2182    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2184    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2185        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2186        entirely. This removes changes made in 7 above.
2188    17. The CMake files have been updated, and there is now more information about
2189        building with CMake in the NON-UNIX-USE document.
2192    Version 7.3 28-Aug-07
2193    ---------------------
2195     1. In the rejigging of the build system that eventually resulted in 7.1, the
2196        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2197        brackets there is not right, since it causes compilers to look for an
2198        installed pcre.h, not the version that is in the source that is being
2199        compiled (which of course may be different). I have changed it back to:
2201          #include "pcre.h"
2203        I have a vague recollection that the change was concerned with compiling in
2204        different directories, but in the new build system, that is taken care of
2205        by the VPATH setting the Makefile.
2207     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2208        when the subject happened to end in the byte 0x85 (e.g. if the last
2209        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2210        characters but of course it shouldn't be taken as a newline when it is part
2211        of another character. The bug was that, for an unlimited repeat of . in
2212        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2213        characters when looking for a newline.
2215     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2217     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2218        in debug output.
2220     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2221        long printing in the pcrecpp unittest when running under MinGW.
2223     6. ESC_K was left out of the EBCDIC table.
2225     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2226        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2227        limit also applies to "virtual nesting" when a pattern is recursive, and in
2228        this case 1000 isn't so big. I have been able to remove this limit at the
2229        expense of backing off one optimization in certain circumstances. Normally,
2230        when pcre_exec() would call its internal match() function recursively and
2231        immediately return the result unconditionally, it uses a "tail recursion"
2232        feature to save stack. However, when a subpattern that can match an empty
2233        string has an unlimited repetition quantifier, it no longer makes this
2234        optimization. That gives it a stack frame in which to save the data for
2235        checking that an empty string has been matched. Previously this was taken
2236        from the 1000-entry workspace that had been reserved. So now there is no
2237        explicit limit, but more stack is used.
2239     8. Applied Daniel's patches to solve problems with the import/export magic
2240        syntax that is required for Windows, and which was going wrong for the
2241        pcreposix and pcrecpp parts of the library. These were overlooked when this
2242        problem was solved for the main library.
2244     9. There were some crude static tests to avoid integer overflow when computing
2245        the size of patterns that contain repeated groups with explicit upper
2246        limits. As the maximum quantifier is 65535, the maximum group length was
2247        set at 30,000 so that the product of these two numbers did not overflow a
2248        32-bit integer. However, it turns out that people want to use groups that
2249        are longer than 30,000 bytes (though not repeat them that many times).
2250        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2251        made it possible to implement the integer overflow checks in a much more
2252        dynamic way, which I have now done. The artificial limitation on group
2253        length has been removed - we now have only the limit on the total length of
2254        the compiled pattern, which depends on the LINK_SIZE setting.
2256    10. Fixed a bug in the documentation for get/copy named substring when
2257        duplicate names are permitted. If none of the named substrings are set, the
2258        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2259        empty string.
2261    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2262        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2263        because the ] is interpreted as the first data character and the
2264        terminating ] is not found. PCRE has been made compatible with Perl in this
2265        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2266        cause memory overwriting.
2268    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2269        string has been matched (to stop an infinite loop). It was not recognizing
2270        a conditional subpattern that could match an empty string if that
2271        subpattern was within another subpattern. For example, it looped when
2272        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
2273        condition was not nested. This bug has been fixed.
2275    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2276        past the start of the subject in the presence of bytes with the top bit
2277        set, for example "\x8aBCD".
2279    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2280        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2282    14. Optimized (?!) to (*FAIL).
2284    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2285        This restricts code points to be within the range 0 to 0x10FFFF, excluding
2286        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2287        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2288        does: it's just the validity check that is more restrictive.
2290    16. Inserted checks for integer overflows during escape sequence (backslash)
2291        processing, and also fixed erroneous offset values for syntax errors during
2292        backslash processing.
2294    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2295        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2297    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2298        caused an overrun.
2300    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2301        something other than just ASCII characters) inside a group that had an
2302        unlimited repeat caused a loop at compile time (while checking to see
2303        whether the group could match an empty string).
2305    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2306        [\P{Any}] did so. (Error in the code for printing property names.)
2308    21. An orphan \E inside a character class could cause a crash.
2310    22. A repeated capturing bracket such as (A)? could cause a wild memory
2311        reference during compilation.
2313    23. There are several functions in pcre_compile() that scan along a compiled
2314        expression for various reasons (e.g. to see if it's fixed length for look
2315        behind). There were bugs in these functions when a repeated \p or \P was
2316        present in the pattern. These operators have additional parameters compared
2317        with \d, etc, and these were not being taken into account when moving along
2318        the compiled data. Specifically:
2320        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2321            length.
2323        (b) An item such as \pL+ within a repeated group could cause crashes or
2324            loops.
2326        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2327            "reference to non-existent subpattern" error.
2329        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2331    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2332        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2334    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2336    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2337        character were causing crashes (broken optimization).
2339    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2340        \p or \P) caused a compile-time loop.
2342    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2343        break. For example, the unstudied pattern [\r\n]A does not match the string
2344        "\r\nA" because change 7.0/46 below moves the current point on by two
2345        characters after failing to match at the start. However, the pattern \nA
2346        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2347        the same is true. There doesn't seem any very clean way out of this, but
2348        what I have chosen to do makes the common cases work: PCRE now takes note
2349        of whether there can be an explicit match for \r or \n anywhere in the
2350        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2351        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2352        pattern has explicit CR or LF references.
2354    29. Added (*CR) etc for changing newline setting at start of pattern.
2357    Version 7.2 19-Jun-07
2358  ---------------------  ---------------------
2360   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 21  Version 7.2 01-May-07 Line 2374  Version 7.2 01-May-07
2374      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
2375      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
2376      in all cases.      in all cases.
2378   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
2380      (a) (?-n) (where n is a string of digits) is a relative subroutine or      (a) (?-n) (where n is a string of digits) is a relative subroutine or
2381          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
2383      (b) (?+n) is also a relative subroutine call; it refers to the nth next      (b) (?+n) is also a relative subroutine call; it refers to the nth next
2384          to be opened parentheses.          to be opened parentheses.
2386      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
2387          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
2389        (d) \K resets the start of the current match so that everything before
2390            is not part of it.
2392        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2394        (f) \g{name} is another synonym - part of Perl 5.10's unification of
2395            reference syntax.
2397        (g) (?| introduces a group in which the numbering of parentheses in each
2398            alternative starts with the same number.
2400        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2402     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2405     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
2406        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2407        for detecting groups that can match an empty string.
2409     9. A pattern with a very large number of alternatives (more than several
2410        hundred) was running out of internal workspace during the pre-compile
2411        phase, where pcre_compile() figures out how much memory will be needed. A
2412        bit of new cunning has reduced the workspace needed for groups with
2413        alternatives. The 1000-alternative test pattern now uses 12 bytes of
2414        workspace instead of running out of the 4096 that are available.
2416    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2418    11. Applied patch from Google to remove an optimization that didn't quite work.
2419        The report of the bug said:
2421          pcrecpp::RE("a*").FullMatch("aaa") matches, while
2422          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2423          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2425    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2426        it matched the wrong number of bytes.
2429  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
2430  ---------------------  ---------------------

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