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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.3 05-Jul-07  Version 8.34 xx-xxxx-201x
5    --------------------------
6    
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
9    
10    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11        this macro is never tested and has no effect, because the work to support
12        coverage involves only compiling and linking options and special targets in
13        the Makefile. The comment in config.h implied that defining the macro would
14        enable coverage support, which is totally false. There was also support for
15        setting this macro in the CMake files (my fault, I just copied it from
16        configure). SUPPORT_GCOV has now been removed.
17    
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
20    
21    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23        these cases). There was also one in pcretest.c.
24    
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
26    
27    6.  In UTF mode, the code for checking whether a group could match an empty
28        string (which is used for indefinitely repeated groups to allow for
29        breaking an infinite loop) was broken when the group contained a repeated
30        negated single-character class with a character that occupied more than one
31        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32        UTF-8 mode). The effect was undefined: the group might or might not be
33        deemed as matching an empty string, or the program might have crashed.
34    
35    7.  The code for checking whether a group could match an empty string was not
36        recognizing that \h, \H, \v, \V, and \R must match a character.
37    
38    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39        an empty string. If it can, pcretest shows this in its information output.
40    
41    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
42        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43        matched by pcre_exec() without using JIT:
44    
45        (a) If the rest of the pattern did not match after a maximal run of
46            grapheme clusters, the code for backing up to try with fewer of them
47            did not always back up over a full grapheme when characters that do not
48            have the modifier quality were involved, e.g. Hangul syllables.
49    
50        (b) If the match point in a subject started with modifier character, and
51            there was no match, the code could incorrectly back up beyond the match
52            point, and potentially beyond the first character in the subject,
53            leading to a segfault or an incorrect match result.
54    
55    
56    Version 8.33 28-May-2013
57    --------------------------
58    
59    1.  Added 'U' to some constants that are compared to unsigned integers, to
60        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
61        variables that are added to signed variables, to ensure the result is
62        signed and can be negated.
63    
64    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
65        CMake config files.
66    
67    3.  Revise the creation of config.h.generic so that all boolean macros are
68        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
69        overriding via -D on the command line possible.
70    
71    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
72        to unsigned int is reported to make a quite noticeable speed difference in
73        a specific Windows environment. Testing on Linux did also appear to show
74        some benefit (and it is clearly not harmful). Also fixed the definition of
75        Xop which should be unsigned.
76    
77    5.  Related to (4), changing the definition of the intermediate variable cc
78        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
79        improvements.
80    
81    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
82        unnecessary spaces.
83    
84    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
85        and later.
86    
87    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
88    
89    9.  Optimizing fast_forward_start_bits in JIT.
90    
91    10. Adding support for callouts in JIT, and fixing some issues revealed
92        during this work. Namely:
93    
94        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
95    
96        (b) Minimum length was not checked before the matching is started.
97    
98    11. The value of capture_last that is passed to callouts was incorrect in some
99        cases when there was a capture on one path that was subsequently abandoned
100        after a backtrack. Also, the capture_last value is now reset after a
101        recursion, since all captures are also reset in this case.
102    
103    12. The interpreter no longer returns the "too many substrings" error in the
104        case when an overflowing capture is in a branch that is subsequently
105        abandoned after a backtrack.
106    
107    13. In the pathological case when an offset vector of size 2 is used, pcretest
108        now prints out the matched string after a yield of 0 or 1.
109    
110    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
111        Only supported by the JIT compiler at the moment.
112    
113    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
114    
115    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
116        offset of the starting point of the matching process, provided the offsets
117        vector is large enough.
118    
119    17. The \A escape now records a lookbehind value of 1, though its execution
120        does not actually inspect the previous character. This is to ensure that,
121        in partial multi-segment matching, at least one character from the old
122        segment is retained when a new segment is processed. Otherwise, if there
123        are no lookbehinds in the pattern, \A might match incorrectly at the start
124        of a new segment.
125    
126    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
127    
128    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
129        gives some modest performance improvement in 8-bit mode.
130    
131    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
132        be expressed in certain programming languages using Universal Character
133        Names.
134    
135    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
136        which points out that "non characters" are not "characters that may not
137        appear in Unicode strings" but rather "characters that are reserved for
138        internal use and have only local meaning".
139    
140    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
141        there was a conditional group that depended on an assertion, if the
142        assertion was false, the callout that immediately followed the alternation
143        in the condition was skipped when pcre_exec() was used for matching.
144    
145    23. Allow an explicit callout to be inserted before an assertion that is the
146        condition for a conditional group, for compatibility with automatic
147        callouts, which always insert a callout at this point.
148    
149    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
150        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
151    
152    25. (*PRUNE) is now supported by the JIT compiler.
153    
154    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
155    
156    27. Fix the case where there are two or more SKIPs with arguments that may be
157        ignored.
158    
159    28. (*SKIP) is now supported by the JIT compiler.
160    
161    29. (*THEN) is now supported by the JIT compiler.
162    
163    30. Update RunTest with additional test selector options.
164    
165    31. The way PCRE handles backtracking verbs has been changed in two ways.
166    
167        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
168        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
169        backtracking. In some cases this makes it more Perl-compatible, but Perl's
170        rather obscure rules do not always do the same thing.
171    
172        (2) Previously, backtracking verbs were confined within assertions. This is
173        no longer the case for positive assertions, except for (*ACCEPT). Again,
174        this sometimes improves Perl compatibility, and sometimes does not.
175    
176    32. A number of tests that were in test 2 because Perl did things differently
177        have been moved to test 1, because either Perl or PCRE has changed, and
178        these tests are now compatible.
179    
180    32. Backtracking control verbs are now handled in the same way in JIT and
181        interpreter.
182    
183    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
184        contained a forward subroutine reference caused a compile error.
185    
186    34. Auto-detect and optimize limited repetitions in JIT.
187    
188    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
189        blocking (*UTF) etc.
190    
191    36. In the interpreter, maximizing pattern repetitions for characters and
192        character types now use tail recursion, which reduces stack usage.
193    
194    37. The value of the max lookbehind was not correctly preserved if a compiled
195        and saved regex was reloaded on a host of different endianness.
196    
197    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
198        of the compiled pattern block, expand the flags field from 16 to 32 bits
199        because it was almost full.
200    
201    39. Try madvise first before posix_madvise.
202    
203    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
204        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
205        original change locked out all matches of empty strings. This has been
206        changed so that one match of an empty string per line is recognized.
207        Subsequent searches on the same line (for colouring or for --only-matching,
208        for example) do not recognize empty strings.
209    
210    41. Applied a user patch to fix a number of spelling mistakes in comments.
211    
212    42. Data lines longer than 65536 caused pcretest to crash.
213    
214    43. Clarified the data type for length and startoffset arguments for pcre_exec
215        and pcre_dfa_exec in the function-specific man pages, where they were
216        explicitly stated to be in bytes, never having been updated. I also added
217        some clarification to the pcreapi man page.
218    
219    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
220        a segmentation fault.
221    
222    
223    Version 8.32 30-November-2012
224    -----------------------------
225    
226    1.  Improved JIT compiler optimizations for first character search and single
227        character iterators.
228    
229    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
230        Patch by Daniel Richard G.
231    
232    3.  Single character iterator optimizations in the JIT compiler.
233    
234    4.  Improved JIT compiler optimizations for character ranges.
235    
236    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
237        Reported by Giuseppe D'Angelo.
238    
239    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
240        of a line, was being set incorrectly in cases where .* appeared inside
241        atomic brackets at the start of a pattern, or where there was a subsequent
242        *PRUNE or *SKIP.
243    
244    7.  Improved instruction cache flush for POWER/PowerPC.
245        Patch by Daniel Richard G.
246    
247    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
248        grep:
249    
250        (a) There is now no limit to the number of patterns to be matched.
251    
252        (b) An error is given if a pattern is too long.
253    
254        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
255            are now supported.
256    
257        (d) --exclude-from and --include-from (multiple use) have been added.
258    
259        (e) Exclusions and inclusions now apply to all files and directories, not
260            just to those obtained from scanning a directory recursively.
261    
262        (f) Multiple uses of -f and --file-list are now supported.
263    
264        (g) In a Windows environment, the default for -d has been changed from
265            "read" (the GNU grep default) to "skip", because otherwise the presence
266            of a directory in the file list provokes an error.
267    
268        (h) The documentation has been revised and clarified in places.
269    
270    9.  Improve the matching speed of capturing brackets.
271    
272    10. Changed the meaning of \X so that it now matches a Unicode extended
273        grapheme cluster.
274    
275    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
276        out POSIX threads when JIT support is configured.
277    
278    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
279    
280    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
281        structure could go wrong in environments where size_t is not the same size
282        as int.
283    
284    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
285        set.
286    
287    15. The EBCDIC support had decayed; later updates to the code had included
288        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
289        general tidy up of EBCDIC-related issues, and the documentation was also
290        not quite right. There is now a test that can be run on ASCII systems to
291        check some of the EBCDIC-related things (but is it not a full test).
292    
293    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
294        in a small tidy to the code.
295    
296    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
297    
298    18. If the --only-matching (-o) option in pcregrep is specified multiple
299        times, each one causes appropriate output. For example, -o1 -o2 outputs the
300        substrings matched by the 1st and 2nd capturing parentheses. A separating
301        string can be specified by --om-separator (default empty).
302    
303    19. Improving the first n character searches.
304    
305    20. Turn case lists for horizontal and vertical white space into macros so that
306        they are defined only once.
307    
308    21. This set of changes together give more compatible Unicode case-folding
309        behaviour for characters that have more than one other case when UCP
310        support is available.
311    
312        (a) The Unicode property table now has offsets into a new table of sets of
313            three or more characters that are case-equivalent. The MultiStage2.py
314            script that generates these tables (the pcre_ucd.c file) now scans
315            CaseFolding.txt instead of UnicodeData.txt for character case
316            information.
317    
318        (b) The code for adding characters or ranges of characters to a character
319            class has been abstracted into a generalized function that also handles
320            case-independence. In UTF-mode with UCP support, this uses the new data
321            to handle characters with more than one other case.
322    
323        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
324            whose other case is greater than 256 are now correctly matched
325            caselessly. Previously, the high codepoint matched the low one, but not
326            vice versa.
327    
328        (d) The processing of \h, \H, \v, and \ in character classes now makes use
329            of the new class addition function, using character lists defined as
330            macros alongside the case definitions of 20 above.
331    
332        (e) Caseless back references now work with characters that have more than
333            one other case.
334    
335        (f) General caseless matching of characters with more than one other case
336            is supported.
337    
338    22. Unicode character properties were updated from Unicode 6.2.0
339    
340    23. Improved CMake support under Windows. Patch by Daniel Richard G.
341    
342    24. Add support for 32-bit character strings, and UTF-32
343    
344    25. Major JIT compiler update (code refactoring and bugfixing).
345        Experimental Sparc 32 support is added.
346    
347    26. Applied a modified version of Daniel Richard G's patch to create
348        pcre.h.generic and config.h.generic by "make" instead of in the
349        PrepareRelease script.
350    
351    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
352        pcre_compile.c when checking for a zero character.
353    
354    28. Introducing a native interface for JIT. Through this interface, the compiled
355        machine code can be directly executed. The purpose of this interface is to
356        provide fast pattern matching, so several sanity checks are not performed.
357        However, feature tests are still performed. The new interface provides
358        1.4x speedup compared to the old one.
359    
360    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
361        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
362        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
363    
364    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
365        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
366        the "old" RFC 2279). Instead, it ended up passing a negative length to
367        pcre_exec().
368    
369    31. Add support for GCC's visibility feature to hide internal functions.
370    
371    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
372        "unknown -C option" after outputting 0 or 1.
373    
374    33. There is now support for generating a code coverage report for the test
375        suite in environments where gcc is the compiler and lcov is installed. This
376        is mainly for the benefit of the developers.
377    
378    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
379        unaddressable using valgrind annotations, allowing valgrind to detect
380        invalid memory accesses. This is mainly for the benefit of the developers.
381    
382    25. (*UTF) can now be used to start a pattern in any of the three libraries.
383    
384    26. Give configure error if --enable-cpp but no C++ compiler found.
385    
386    
387    Version 8.31 06-July-2012
388    -------------------------
389    
390    1.  Fixing a wrong JIT test case and some compiler warnings.
391    
392    2.  Removed a bashism from the RunTest script.
393    
394    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
395        to unsigned type, result still unsigned" that was given by an MS compiler
396        on encountering the code "-sizeof(xxx)".
397    
398    4.  Partial matching support is added to the JIT compiler.
399    
400    5.  Fixed several bugs concerned with partial matching of items that consist
401        of more than one character:
402    
403        (a) /^(..)\1/ did not partially match "aba" because checking references was
404            done on an "all or nothing" basis. This also applied to repeated
405            references.
406    
407        (b) \R did not give a hard partial match if \r was found at the end of the
408            subject.
409    
410        (c) \X did not give a hard partial match after matching one or more
411            characters at the end of the subject.
412    
413        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
414            a partial match for the string "\r".
415    
416        (e) When newline was set to CRLF, the metacharacter "." did not recognize
417            a partial match for a CR character at the end of the subject string.
418    
419    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
420        running pcretest, the text "(JIT)" added to the output whenever JIT is
421        actually used to run the match.
422    
423    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
424        or /S+[+] with a digit between 1 and 7.
425    
426    8.  OP_NOT now supports any UTF character not just single-byte ones.
427    
428    9.  (*MARK) control verb is now supported by the JIT compiler.
429    
430    10. The command "./RunTest list" lists the available tests without actually
431        running any of them. (Because I keep forgetting what they all are.)
432    
433    11. Add PCRE_INFO_MAXLOOKBEHIND.
434    
435    12. Applied a (slightly modified) user-supplied patch that improves performance
436        when the heap is used for recursion (compiled with --disable-stack-for-
437        recursion). Instead of malloc and free for each heap frame each time a
438        logical recursion happens, frames are retained on a chain and re-used where
439        possible. This sometimes gives as much as 30% improvement.
440    
441    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
442        call.
443    
444    14. As documented, (*COMMIT) is now confined to within a positive assertion.
445    
446    15. It is now possible to link pcretest with libedit as an alternative to
447        libreadline.
448    
449    16. (*COMMIT) control verb is now supported by the JIT compiler.
450    
451    17. The Unicode data tables have been updated to Unicode 6.1.0.
452    
453    18. Added --file-list option to pcregrep.
454    
455    19. Added binary file support to pcregrep, including the -a, --binary-files,
456        -I, and --text options.
457    
458    20. The madvise function is renamed for posix_madvise for QNX compatibility
459        reasons. Fixed by Giuseppe D'Angelo.
460    
461    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
462    
463    22. Changed the option for creating symbolic links for 16-bit man pages from
464        -s to -sf so that re-installing does not cause issues.
465    
466    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
467    
468    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
469        matches in certain environments (the workspace was not being correctly
470        retained). Also added to pcre_dfa_exec() a simple plausibility check on
471        some of the workspace data at the beginning of a restart.
472    
473    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
474        was not doing so when it should - probably a typo introduced by SVN 528
475        (change 8.10/14).
476    
477    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
478        \w+ when the character tables indicated that \x{c4} was a word character.
479        There were several related cases, all because the tests for doing a table
480        lookup were testing for characters less than 127 instead of 255.
481    
482    27. If a pattern contains capturing parentheses that are not used in a match,
483        their slots in the ovector are set to -1. For those that are higher than
484        any matched groups, this happens at the end of processing. In the case when
485        there were back references that the ovector was too small to contain
486        (causing temporary malloc'd memory to be used during matching), and the
487        highest capturing number was not used, memory off the end of the ovector
488        was incorrectly being set to -1. (It was using the size of the temporary
489        memory instead of the true size.)
490    
491    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
492        ovector size, it uses memory at the end of the block that it has got.
493    
494    29. Check for an overlong MARK name and give an error at compile time. The
495        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
496    
497    30. JIT compiler update.
498    
499    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
500        Rill for the patch.
501    
502    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
503    
504    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
505    
506    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
507        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
508        was enabled.
509    
510    35. Improve JIT code generation for greedy plus quantifier.
511    
512    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
513        1 to "aa" instead of to an empty string. The bug affected repeated groups
514        that could potentially match an empty string.
515    
516    37. Optimizing single character iterators in JIT.
517    
518    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
519        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
520        codepoints that are too big for the mode are faulted, and in a UTF mode,
521        disallowed codepoints are also faulted.
522    
523    39. If PCRE was compiled with UTF support, in three places in the DFA
524        matcher there was code that should only have been obeyed in UTF mode, but
525        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
526        processing when bytes with values greater than 127 were present. In 16-bit
527        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
528        both cases the values are those that cannot be the first data item in a UTF
529        character. The three items that might have provoked this were recursions,
530        possessively repeated groups, and atomic groups.
531    
532    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
533        and pcregrep, because some OS require shared objects to be explicitly
534        passed to ld, causing the link step to fail if they are not.
535    
536    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
537        mode, patterns that started with \h* or \R* might be incorrectly matched.
538    
539    
540    Version 8.30 04-February-2012
541    -----------------------------
542    
543    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
544        name is defined in ctype.h.
545    
546    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
547        only in quite long subpatterns.
548    
549    3.  Removed the function pcre_info(), which has been obsolete and deprecated
550        since it was replaced by pcre_fullinfo() in February 2000.
551    
552    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
553        match a (*MARK), and the match failed at the start of the subject, a
554        reference to memory before the start of the subject could occur. This bug
555        was introduced by fix 17 of release 8.21.
556    
557    5.  A reference to an unset group with zero minimum repetition was giving
558        totally wrong answers (in non-JavaScript-compatibility mode). For example,
559        /(another)?(\1?)test/ matched against "hello world test". This bug was
560        introduced in release 8.13.
561    
562    6.  Add support for 16-bit character strings (a large amount of work involving
563        many changes and refactorings).
564    
565    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
566        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
567        from a file.
568    
569    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
570        rounding is not applied in this particular case).
571    
572    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
573        if they appear, or are escaped, in patterns.
574    
575    10. Get rid of a number of -Wunused-but-set-variable warnings.
576    
577    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
578        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
579        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
580        also returns the mark "x". This bug applied to capturing parentheses,
581        non-capturing parentheses, and atomic parentheses. It also applied to some
582        assertions.
583    
584    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
585        information out of configure.ac instead of relying on pcre.h.generic, which
586        is not stored in the repository.
587    
588    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
589        -lreadline.
590    
591    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
592    
593    15. Applied Graycode's patch to put the top-level frame on the stack rather
594        than the heap when not using the stack for recursion. This gives a
595        performance improvement in many cases when recursion is not deep.
596    
597    16. Experimental code added to "pcretest -C" to output the stack frame size.
598    
599    
600    Version 8.21 12-Dec-2011
601    ------------------------
602    
603    1.  Updating the JIT compiler.
604    
605    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
606        are added as well.
607    
608    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
609        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
610        calling _pcre_jit_exec. Some extra comments are added.
611    
612    4.  (*MARK) settings inside atomic groups that do not contain any capturing
613        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
614        was introduced by change 18 for 8.20.
615    
616    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
617        ECMA-262 standard.
618    
619    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
620        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
621        This bug was probably introduced by change 9 of 8.13.
622    
623    7.  While fixing 6 above, I noticed that a number of other items were being
624        incorrectly rejected as "not fixed length". This arose partly because newer
625        opcodes had not been added to the fixed-length checking code. I have (a)
626        corrected the bug and added tests for these items, and (b) arranged for an
627        error to occur if an unknown opcode is encountered while checking for fixed
628        length instead of just assuming "not fixed length". The items that were
629        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
630        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
631        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
632    
633    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
634        being incorrectly compiled and would have given unpredicatble results.
635    
636    9.  A possessively repeated subpattern with minimum repeat count greater than
637        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
638        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
639        the first (A) could occur when it should not.
640    
641    10. Add a cast and remove a redundant test from the code.
642    
643    11. JIT should use pcre_malloc/pcre_free for allocation.
644    
645    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
646        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
647        is anything other than /usr, -L is still shown).
648    
649    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
650    
651    14. Perl does not support \N without a following name in a [] class; PCRE now
652        also gives an error.
653    
654    15. If a forward reference was repeated with an upper limit of around 2000,
655        it caused the error "internal error: overran compiling workspace". The
656        maximum number of forward references (including repeats) was limited by the
657        internal workspace, and dependent on the LINK_SIZE. The code has been
658        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
659        the default depends on LINK_SIZE. There is a new upper limit (for safety)
660        of around 200,000 forward references. While doing this, I also speeded up
661        the filling in of repeated forward references.
662    
663    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
664        incorrectly expecting the subject to contain another "a" after the start.
665    
666    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
667        in the match, the SKIP should be ignored. This was not happening; instead
668        the SKIP was being treated as NOMATCH. For patterns such as
669        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
670        tested.
671    
672    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
673        now much more compatible with Perl, in particular in cases where the result
674        is a non-match for a non-anchored pattern. For example, if
675        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
676        "m", where previously it did not return a name. A side effect of this
677        change is that for partial matches, the last encountered mark name is
678        returned, as for non matches. A number of tests that were previously not
679        Perl-compatible have been moved into the Perl-compatible test files. The
680        refactoring has had the pleasing side effect of removing one argument from
681        the match() function, thus reducing its stack requirements.
682    
683    19. If the /S+ option was used in pcretest to study a pattern using JIT,
684        subsequent uses of /S (without +) incorrectly behaved like /S+.
685    
686    21. Retrieve executable code size support for the JIT compiler and fixing
687        some warnings.
688    
689    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
690        not work when the shorter character appeared right at the end of the
691        subject string.
692    
693    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
694        systems.
695    
696    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
697        output it when the /M option is used in pcretest.
698    
699    25. The CheckMan script was not being included in the distribution. Also, added
700        an explicit "perl" to run Perl scripts from the PrepareRelease script
701        because this is reportedly needed in Windows.
702    
703    26. If study data was being save in a file and studying had not found a set of
704        "starts with" bytes for the pattern, the data written to the file (though
705        never used) was taken from uninitialized memory and so caused valgrind to
706        complain.
707    
708    27. Updated RunTest.bat as provided by Sheri Pierce.
709    
710    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
711    
712    29. Computation of memory usage for the table of capturing group names was
713        giving an unnecessarily large value.
714    
715    
716    Version 8.20 21-Oct-2011
717    ------------------------
718    
719    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
720        a POSIX class. After further experiments with Perl, which convinced me that
721        Perl has bugs and confusions, a closing square bracket is no longer allowed
722        in a POSIX name. This bug also affected patterns with classes that started
723        with full stops.
724    
725    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
726        captured substring, but while checking the failing first alternative,
727        substring 1 is temporarily captured. If the output vector supplied to
728        pcre_exec() was not big enough for this capture, the yield of the function
729        was still zero ("insufficient space for captured substrings"). This cannot
730        be totally fixed without adding another stack variable, which seems a lot
731        of expense for a edge case. However, I have improved the situation in cases
732        such as /(a)(b)x|abc/ matched against "abc", where the return code
733        indicates that fewer than the maximum number of slots in the ovector have
734        been set.
735    
736    3.  Related to (2) above: when there are more back references in a pattern than
737        slots in the output vector, pcre_exec() uses temporary memory during
738        matching, and copies in the captures as far as possible afterwards. It was
739        using the entire output vector, but this conflicts with the specification
740        that only 2/3 is used for passing back captured substrings. Now it uses
741        only the first 2/3, for compatibility. This is, of course, another edge
742        case.
743    
744    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
745        main code base, and can be used by building with --enable-jit. When this is
746        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
747        runtime --no-jit option is given.
748    
749    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
750        ovector, the return from the function was zero, implying that there were
751        other matches that did not fit. The correct "exactly full" value is now
752        returned.
753    
754    6.  If a subpattern that was called recursively or as a subroutine contained
755        (*PRUNE) or any other control that caused it to give a non-standard return,
756        invalid errors such as "Error -26 (nested recursion at the same subject
757        position)" or even infinite loops could occur.
758    
759    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
760        computing the minimum length on reaching *ACCEPT, and so ended up with the
761        wrong value of 1 rather than 0. Further investigation indicates that
762        computing a minimum subject length in the presence of *ACCEPT is difficult
763        (think back references, subroutine calls), and so I have changed the code
764        so that no minimum is registered for a pattern that contains *ACCEPT.
765    
766    8.  If (*THEN) was present in the first (true) branch of a conditional group,
767        it was not handled as intended. [But see 16 below.]
768    
769    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
770        Sheri Pierce.
771    
772    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
773        the first byte in a match must be "a".
774    
775    11. Change 17 for 8.13 increased the recursion depth for patterns like
776        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
777        pattern contains any instances of (*THEN). If it does not, the old
778        optimizations are restored. It would be nice to do this on a per-group
779        basis, but at the moment that is not feasible.
780    
781    12. In some environments, the output of pcretest -C is CRLF terminated. This
782        broke RunTest's code that checks for the link size. A single white space
783        character after the value is now allowed for.
784    
785    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
786        For "fr", it uses the Windows-specific input and output files.
787    
788    14. If (*THEN) appeared in a group that was called recursively or as a
789        subroutine, it did not work as intended. [But see next item.]
790    
791    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
792        pattern fragments (but not containing any | characters). If A and B are
793        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
794        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
795        D. In other words, Perl considers parentheses that do not contain any |
796        characters to be part of a surrounding alternative, whereas PCRE was
797        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
798        differently. PCRE now behaves in the same way as Perl, except in the case
799        of subroutine/recursion calls such as (?1) which have in any case always
800        been different (but PCRE had them first :-).
801    
802    16. Related to 15 above: Perl does not treat the | in a conditional group as
803        creating alternatives. Such a group is treated in the same way as an
804        ordinary group without any | characters when processing (*THEN). PCRE has
805        been changed to match Perl's behaviour.
806    
807    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
808        RunGrepTest script failed.
809    
810    18. Change 22 for version 13 caused atomic groups to use more stack. This is
811        inevitable for groups that contain captures, but it can lead to a lot of
812        stack use in large patterns. The old behaviour has been restored for atomic
813        groups that do not contain any capturing parentheses.
814    
815    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
816        suppress the check for a minimum subject length at run time. (If it was
817        given to pcre_exec() or pcre_dfa_exec() it did work.)
818    
819    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
820        fail to work when decoding hex characters in data strings in EBCDIC
821        environments.
822    
823    21. It appears that in at least one Mac OS environment, the isxdigit() function
824        is implemented as a macro that evaluates to its argument more than once,
825        contravening the C 90 Standard (I haven't checked a later standard). There
826        was an instance in pcretest which caused it to go wrong when processing
827        \x{...} escapes in subject strings. The has been rewritten to avoid using
828        things like p++ in the argument of isxdigit().
829    
830    
831    Version 8.13 16-Aug-2011
832    ------------------------
833    
834    1.  The Unicode data tables have been updated to Unicode 6.0.0.
835    
836    2.  Two minor typos in pcre_internal.h have been fixed.
837    
838    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
839        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
840        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
841    
842    4.  There were a number of related bugs in the code for matching backrefences
843        caselessly in UTF-8 mode when codes for the characters concerned were
844        different numbers of bytes. For example, U+023A and U+2C65 are an upper
845        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
846        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
847        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
848        2-byte code at the end of the subject (it thought there wasn't enough data
849        left).
850    
851    5.  Comprehensive information about what went wrong is now returned by
852        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
853        as the output vector has at least 2 elements. The offset of the start of
854        the failing character and a reason code are placed in the vector.
855    
856    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
857        now returned is for the first byte of the failing character, instead of the
858        last byte inspected. This is an incompatible change, but I hope it is small
859        enough not to be a problem. It makes the returned offset consistent with
860        pcre_exec() and pcre_dfa_exec().
861    
862    7.  pcretest now gives a text phrase as well as the error number when
863        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
864        failure, the offset and reason code are output.
865    
866    8.  When \R was used with a maximizing quantifier it failed to skip backwards
867        over a \r\n pair if the subsequent match failed. Instead, it just skipped
868        back over a single character (\n). This seems wrong (because it treated the
869        two characters as a single entity when going forwards), conflicts with the
870        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
871        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
872        has been changed.
873    
874    9.  Some internal refactoring has changed the processing so that the handling
875        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
876        time (the PCRE_DOTALL option was changed this way some time ago: version
877        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
878        which was always a bit of a fudge. It also means that there is one less
879        argument for the match() function, which reduces its stack requirements
880        slightly. This change also fixes an incompatibility with Perl: the pattern
881        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
882    
883    10. More internal refactoring has drastically reduced the number of recursive
884        calls to match() for possessively repeated groups such as (abc)++ when
885        using pcre_exec().
886    
887    11. While implementing 10, a number of bugs in the handling of groups were
888        discovered and fixed:
889    
890        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
891        (a|)*(?1) gave a compile-time internal error.
892        ((a|)+)+  did not notice that the outer group could match an empty string.
893        (^a|^)+   was not marked as anchored.
894        (.*a|.*)+ was not marked as matching at start or after a newline.
895    
896    12. Yet more internal refactoring has removed another argument from the match()
897        function. Special calls to this function are now indicated by setting a
898        value in a variable in the "match data" data block.
899    
900    13. Be more explicit in pcre_study() instead of relying on "default" for
901        opcodes that mean there is no starting character; this means that when new
902        ones are added and accidentally left out of pcre_study(), testing should
903        pick them up.
904    
905    14. The -s option of pcretest has been documented for ages as being an old
906        synonym of -m (show memory usage). I have changed it to mean "force study
907        for every regex", that is, assume /S for every regex. This is similar to -i
908        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
909        using it. It makes it easier to run collections of tests with and without
910        study enabled, and thereby test pcre_study() more easily. All the standard
911        tests are now run with and without -s (but some patterns can be marked as
912        "never study" - see 20 below).
913    
914    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
915        restoration of the capturing data to the outer values was not happening
916        correctly.
917    
918    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
919        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
920        pattern had matched an empty string, and so incorrectly returned a no
921        match.
922    
923    17. There was optimizing code for the last branch of non-capturing parentheses,
924        and also for the obeyed branch of a conditional subexpression, which used
925        tail recursion to cut down on stack usage. Unfortunately, now that there is
926        the possibility of (*THEN) occurring in these branches, tail recursion is
927        no longer possible because the return has to be checked for (*THEN). These
928        two optimizations have therefore been removed. [But see 8.20/11 above.]
929    
930    18. If a pattern containing \R was studied, it was assumed that \R always
931        matched two bytes, thus causing the minimum subject length to be
932        incorrectly computed because \R can also match just one byte.
933    
934    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
935        was incorrectly computed.
936    
937    20. If /S is present twice on a test pattern in pcretest input, it now
938        *disables* studying, thereby overriding the use of -s on the command line
939        (see 14 above). This is necessary for one or two tests to keep the output
940        identical in both cases.
941    
942    21. When (*ACCEPT) was used in an assertion that matched an empty string and
943        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
944    
945    22. When an atomic group that contained a capturing parenthesis was
946        successfully matched, but the branch in which it appeared failed, the
947        capturing was not being forgotten if a higher numbered group was later
948        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
949        group 1 to "a", when in fact it should be unset. This applied to multi-
950        branched capturing and non-capturing groups, repeated or not, and also to
951        positive assertions (capturing in negative assertions does not happen
952        in PCRE) and also to nested atomic groups.
953    
954    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
955        subject after a captured substring, to make it easier to tell which of a
956        number of identical substrings has been captured.
957    
958    24. The way atomic groups are processed by pcre_exec() has been changed so that
959        if they are repeated, backtracking one repetition now resets captured
960        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
961        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
962        "aaa". Previously, it would have been "a". As part of this code
963        refactoring, the way recursive calls are handled has also been changed.
964    
965    25. If an assertion condition captured any substrings, they were not passed
966        back unless some other capturing happened later. For example, if
967        (?(?=(a))a) was matched against "a", no capturing was returned.
968    
969    26. When studying a pattern that contained subroutine calls or assertions,
970        the code for finding the minimum length of a possible match was handling
971        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
972        group 1 called group 2 while simultaneously a separate group 2 called group
973        1). A stack overflow occurred in this case. I have fixed this by limiting
974        the recursion depth to 10.
975    
976    27. Updated RunTest.bat in the distribution to the version supplied by Tom
977        Fortmann. This supports explicit test numbers on the command line, and has
978        argument validation and error reporting.
979    
980    28. An instance of \X with an unlimited repeat could fail if at any point the
981        first character it looked at was a mark character.
982    
983    29. Some minor code refactoring concerning Unicode properties and scripts
984        should reduce the stack requirement of match() slightly.
985    
986    30. Added the '=' option to pcretest to check the setting of unused capturing
987        slots at the end of the pattern, which are documented as being -1, but are
988        not included in the return count.
989    
990    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
991        compiled something random. Now it gives a compile-time error (as does
992        Perl).
993    
994    32. A *MARK encountered during the processing of a positive assertion is now
995        recorded and passed back (compatible with Perl).
996    
997    33. If --only-matching or --colour was set on a pcregrep call whose pattern
998        had alternative anchored branches, the search for a second match in a line
999        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1000        matched the line "0102" twice. The same bug affected patterns that started
1001        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1002        twice.
1003    
1004    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1005        does, and because of capturing effects, quantifying parenthesized
1006        assertions may at times be useful. Quantifiers are now allowed for
1007        parenthesized assertions.
1008    
1009    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1010    
1011    36. \g was being checked for fancy things in a character class, when it should
1012        just be a literal "g".
1013    
1014    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1015        appearance of a nested POSIX class supersedes an apparent external class.
1016        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1017        unescaped square brackets may also appear as part of class names. For
1018        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1019        more like Perl. (But see 8.20/1 above.)
1020    
1021    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1022        was because it thought it was \N{name}, which is not supported).
1023    
1024    39. Add minix to OS list not supporting the -S option in pcretest.
1025    
1026    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1027        cannot analyze patterns in sufficient detail to catch mutual recursions
1028        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1029        subgroup is called recursively as a subpattern for a second time at the
1030        same position in the subject string. In previous releases this might have
1031        been caught by the recursion limit, or it might have run out of stack.
1032    
1033    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1034        happen only once. PCRE was, however incorrectly giving a compile time error
1035        "recursive call could loop indefinitely" because it cannot analyze the
1036        pattern in sufficient detail. The compile time test no longer happens when
1037        PCRE is compiling a conditional subpattern, but actual runaway loops are
1038        now caught at runtime (see 40 above).
1039    
1040    42. It seems that Perl allows any characters other than a closing parenthesis
1041        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1042        has been changed to be the same.
1043    
1044    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1045        as not to get warnings when autogen.sh is called. Also changed
1046        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1047    
1048    44. To help people who use pcregrep to scan files containing exceedingly long
1049        lines, the following changes have been made:
1050    
1051        (a) The default value of the buffer size parameter has been increased from
1052            8K to 20K. (The actual buffer used is three times this size.)
1053    
1054        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1055            PCRE is built.
1056    
1057        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1058            to be set at run time.
1059    
1060        (d) Numerical values in pcregrep options can be followed by K or M, for
1061            example --buffer-size=50K.
1062    
1063        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1064            given and the return code is set to 2.
1065    
1066    45. Add a pointer to the latest mark to the callout data block.
1067    
1068    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1069        partial match of an empty string instead of no match. This was specific to
1070        the use of ".".
1071    
1072    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1073        complete match instead of a partial match. This bug was dependent on both
1074        the PCRE_UTF8 and PCRE_DOTALL options being set.
1075    
1076    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1077        starting byte set, because \b was not being ignored.
1078    
1079    
1080    Version 8.12 15-Jan-2011
1081    ------------------------
1082    
1083    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1084        checks for such things as part of the documentation building process.
1085    
1086    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1087        --match-limit and --recursion-limit options (added for 8.11). In
1088        particular, this made one of the standard tests fail. (The integer value
1089        went into the wrong half of a long int.)
1090    
1091    3.  If the --colour option was given to pcregrep with -v (invert match), it
1092        did strange things, either producing crazy output, or crashing. It should,
1093        of course, ignore a request for colour when reporting lines that do not
1094        match.
1095    
1096    4.  Another pcregrep bug caused similar problems if --colour was specified with
1097        -M (multiline) and the pattern match finished with a line ending.
1098    
1099    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1100        matched in multiline mode, the following line was shown as part of the
1101        match. This seems wrong, so I have changed it.
1102    
1103    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1104        the check for further matches in the same line (so they could be coloured)
1105        to overrun the end of the current line. If another match was found, it was
1106        incorrectly shown (and then shown again when found in the next line).
1107    
1108    7.  If pcregrep was compiled under Windows, there was a reference to the
1109        function pcregrep_exit() before it was defined. I am assuming this was
1110        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1111        reported by a user. I've moved the definition above the reference.
1112    
1113    
1114    Version 8.11 10-Dec-2010
1115    ------------------------
1116    
1117    1.  (*THEN) was not working properly if there were untried alternatives prior
1118        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1119        backtracked to try for "b" instead of moving to the next alternative branch
1120        at the same level (in this case, to look for "c"). The Perl documentation
1121        is clear that when (*THEN) is backtracked onto, it goes to the "next
1122        alternative in the innermost enclosing group".
1123    
1124    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1125        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1126        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1127        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1128        (*THEN).
1129    
1130    3.  If \s appeared in a character class, it removed the VT character from
1131        the class, even if it had been included by some previous item, for example
1132        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1133        of \s, but is part of the POSIX "space" class.)
1134    
1135    4.  A partial match never returns an empty string (because you can always
1136        match an empty string at the end of the subject); however the checking for
1137        an empty string was starting at the "start of match" point. This has been
1138        changed to the "earliest inspected character" point, because the returned
1139        data for a partial match starts at this character. This means that, for
1140        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1141        (previously it gave "no match").
1142    
1143    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1144        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1145        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1146        has an implication that the given string is incomplete (because a partial
1147        match is preferred over a full match). For this reason, these items now
1148        give a partial match in this situation. [Aside: previously, the one case
1149        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1150        match rather than a full match, which was wrong by the old rules, but is
1151        now correct.]
1152    
1153    6.  There was a bug in the handling of #-introduced comments, recognized when
1154        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1155        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1156        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1157        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1158        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1159        places in pcre_compile().
1160    
1161    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1162        comments when looking ahead for named forward references to subpatterns,
1163        the only newline sequence it recognized was NL. It now handles newlines
1164        according to the set newline convention.
1165    
1166    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1167        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1168        cater for a lack of strerror(). These oversights have been fixed.
1169    
1170    9.  Added --match-limit and --recursion-limit to pcregrep.
1171    
1172    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1173    
1174    11. When the -o option was used, pcregrep was setting a return code of 1, even
1175        when matches were found, and --line-buffered was not being honoured.
1176    
1177    12. Added an optional parentheses number to the -o and --only-matching options
1178        of pcregrep.
1179    
1180    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1181        can match an empty string. The code to do it in pcretest and pcredemo
1182        needed fixing:
1183    
1184        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1185            only one byte after an empty string match just before CRLF (this case
1186            just got forgotten; "any" and "anycrlf" were OK).
1187    
1188        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1189            mode when an empty string match preceded an ASCII character followed by
1190            a non-ASCII character. (The code for advancing by one character rather
1191            than one byte was nonsense.)
1192    
1193        (c) The pcredemo.c sample program did not have any code at all to handle
1194            the cases when CRLF is a valid newline sequence.
1195    
1196    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1197        as a starting offset was within the subject string. There is now a new
1198        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1199        negative or greater than the length of the string. In order to test this,
1200        pcretest is extended to allow the setting of negative starting offsets.
1201    
1202    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1203        starting offset points to the beginning of a UTF-8 character was
1204        unnecessarily clumsy. I tidied it up.
1205    
1206    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1207        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1208    
1209    17. Nobody had reported that the --include_dir option, which was added in
1210        release 7.7 should have been called --include-dir (hyphen, not underscore)
1211        for compatibility with GNU grep. I have changed it to --include-dir, but
1212        left --include_dir as an undocumented synonym, and the same for
1213        --exclude-dir, though that is not available in GNU grep, at least as of
1214        release 2.5.4.
1215    
1216    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1217        characters from a string of bytes) have been redefined so as not to use
1218        loops, in order to improve performance in some environments. At the same
1219        time, I abstracted some of the common code into auxiliary macros to save
1220        repetition (this should not affect the compiled code).
1221    
1222    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1223        compile-time error is now given if \c is not followed by an ASCII
1224        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1225        different, and any byte value is allowed.)
1226    
1227    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1228        START_OPTIMIZE option, which is now allowed at compile time - but just
1229        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1230        to pcregrep and other applications that have no direct access to PCRE
1231        options. The new /Y option in pcretest sets this option when calling
1232        pcre_compile().
1233    
1234    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1235        back references. Groups containing recursive back references were forced to
1236        be atomic by that change, but in the case of named groups, the amount of
1237        memory required was incorrectly computed, leading to "Failed: internal
1238        error: code overflow". This has been fixed.
1239    
1240    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1241        pcretest.c, to avoid build problems in some Borland environments.
1242    
1243    
1244    Version 8.10 25-Jun-2010
1245    ------------------------
1246    
1247    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1248        THEN.
1249    
1250    2.  (*ACCEPT) was not working when inside an atomic group.
1251    
1252    3.  Inside a character class, \B is treated as a literal by default, but
1253        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1254        causes the error). The code is unchanged, but I tidied the documentation.
1255    
1256    4.  Inside a character class, PCRE always treated \R and \X as literals,
1257        whereas Perl faults them if its -w option is set. I have changed PCRE so
1258        that it faults them when PCRE_EXTRA is set.
1259    
1260    5.  Added support for \N, which always matches any character other than
1261        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1262    
1263    6.  When compiling pcregrep with newer versions of gcc which may have
1264        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1265        declared with attribute warn_unused_result" were given. Just casting the
1266        result to (void) does not stop the warnings; a more elaborate fudge is
1267        needed. I've used a macro to implement this.
1268    
1269    7.  Minor change to pcretest.c to avoid a compiler warning.
1270    
1271    8.  Added four artifical Unicode properties to help with an option to make
1272        \s etc use properties (see next item). The new properties are: Xan
1273        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1274    
1275    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1276        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1277        this option. Modified pcretest to add /W to test this facility. Added
1278        REG_UCP to make it available via the POSIX interface.
1279    
1280    10. Added --line-buffered to pcregrep.
1281    
1282    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1283        studied, and the match started with a letter with a code point greater than
1284        127 whose first byte was different to the first byte of the other case of
1285        the letter, the other case of this starting letter was not recognized
1286        (#976).
1287    
1288    12. If a pattern that was studied started with a repeated Unicode property
1289        test, for example, \p{Nd}+, there was the theoretical possibility of
1290        setting up an incorrect bitmap of starting bytes, but fortunately it could
1291        not have actually happened in practice until change 8 above was made (it
1292        added property types that matched character-matching opcodes).
1293    
1294    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1295        possible starting bytes for non-anchored patterns.
1296    
1297    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1298        \R, and also a number of cases that involve Unicode properties, both
1299        explicit and implicit when PCRE_UCP is set.
1300    
1301    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1302        input, it could crash or give wrong results if characters with values
1303        greater than 0xc0 were present in the subject string. (Detail: it assumed
1304        UTF-8 input when processing these items.)
1305    
1306    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1307        size_t is 64-bit (#991).
1308    
1309    17. Added a check for running out of memory when PCRE is compiled with
1310        --disable-stack-for-recursion (#990).
1311    
1312    18. If the last data line in a file for pcretest does not have a newline on
1313        the end, a newline was missing in the output.
1314    
1315    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1316        less than 128) in its various bitmaps. However, there is a facility for
1317        generating tables according to the current locale when PCRE is compiled. It
1318        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1319        characters, are recognized by isspace() and therefore were getting set in
1320        these tables, and indeed these tables seem to approximate to ISO 8859. This
1321        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1322        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1323        which of course cannot start UTF-8 characters. I have changed the code so
1324        that only real ASCII characters (less than 128) and the correct starting
1325        bytes for UTF-8 encodings are set for characters greater than 127 when in
1326        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1327        altogether.)
1328    
1329    20. Added the /T option to pcretest so as to be able to run tests with non-
1330        standard character tables, thus making it possible to include the tests
1331        used for 19 above in the standard set of tests.
1332    
1333    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1334        reference to a subpattern the other side of a comment that contains an
1335        opening parenthesis caused either an internal compiling error, or a
1336        reference to the wrong subpattern.
1337    
1338    
1339    Version 8.02 19-Mar-2010
1340    ------------------------
1341    
1342    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1343    
1344    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1345        configured.
1346    
1347    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1348        original author of that file, following a query about its status.
1349    
1350    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1351        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1352    
1353    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1354        quantifier applied to a forward-referencing subroutine call, could compile
1355        incorrect code or give the error "internal error: previously-checked
1356        referenced subpattern not found".
1357    
1358    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1359        variables to point to external functions. For these systems, therefore,
1360        pcre_malloc etc. are now initialized to local functions that call the
1361        relevant global functions.
1362    
1363    7.  There were two entries missing in the vectors called coptable and poptable
1364        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1365        I've fixed the data, and added a kludgy way of testing at compile time that
1366        the lengths are correct (equal to the number of opcodes).
1367    
1368    8.  Following on from 7, I added a similar kludge to check the length of the
1369        eint vector in pcreposix.c.
1370    
1371    9.  Error texts for pcre_compile() are held as one long string to avoid too
1372        much relocation at load time. To find a text, the string is searched,
1373        counting zeros. There was no check for running off the end of the string,
1374        which could happen if a new error number was added without updating the
1375        string.
1376    
1377    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1378    
1379    11. \K was not working if it appeared in an atomic group or in a group that
1380        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1381        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1382        the assertion is positive, but not if it is negative.
1383    
1384    12. Change 11 fortuitously reduced the size of the stack frame used in the
1385        "match()" function of pcre_exec.c by one pointer. Forthcoming
1386        implementation of support for (*MARK) will need an extra pointer on the
1387        stack; I have reserved it now, so that the stack frame size does not
1388        decrease.
1389    
1390    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1391        item in branch that calls a recursion is a subroutine call - as in the
1392        second branch in the above example - was incorrectly given the compile-
1393        time error "recursive call could loop indefinitely" because pcre_compile()
1394        was not correctly checking the subroutine for matching a non-empty string.
1395    
1396    14. The checks for overrunning compiling workspace could trigger after an
1397        overrun had occurred. This is a "should never occur" error, but it can be
1398        triggered by pathological patterns such as hundreds of nested parentheses.
1399        The checks now trigger 100 bytes before the end of the workspace.
1400    
1401    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1402    
1403    
1404    Version 8.01 19-Jan-2010
1405    ------------------------
1406    
1407    1.  If a pattern contained a conditional subpattern with only one branch (in
1408        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1409        computed the wrong minimum data length (which is of course zero for such
1410        subpatterns). This could cause incorrect "no match" results.
1411    
1412    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1413        the pattern is reset in the first branch, pcre_compile() failed with
1414        "internal error: code overflow at offset...". This happened only when
1415        the reset was to the original external option setting. (An optimization
1416        abstracts leading options settings into an external setting, which was the
1417        cause of this.)
1418    
1419    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1420        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1421        assertion pattern did not match (meaning that the assertion was true), it
1422        was incorrectly treated as false if the SKIP had been reached during the
1423        matching. This also applied to assertions used as conditions.
1424    
1425    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1426        assertion subpattern, including such a pattern used as a condition,
1427        unpredictable results occurred, instead of the error return
1428        PCRE_ERROR_DFA_UITEM.
1429    
1430    5.  The C++ GlobalReplace function was not working like Perl for the special
1431        situation when an empty string is matched. It now does the fancy magic
1432        stuff that is necessary.
1433    
1434    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1435        removed. (These were left over from very, very early versions of PCRE.)
1436    
1437    7.  Some cosmetic changes to the code to make life easier when compiling it
1438        as part of something else:
1439    
1440        (a) Change DEBUG to PCRE_DEBUG.
1441    
1442        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1443            called "current" as "current_branch", to prevent a collision with the
1444            Linux macro when compiled as a kernel module.
1445    
1446        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1447            prevent a collision with the Linux macro when compiled as a kernel
1448            module.
1449    
1450    8.  In pcre_compile() there are some checks for integer overflows that used to
1451        cast potentially large values to (double). This has been changed to that
1452        when building, a check for int64_t is made, and if it is found, it is used
1453        instead, thus avoiding the use of floating point arithmetic. (There is no
1454        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1455        double.
1456    
1457    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1458        2005 (difference between two addresses compared to an unsigned value).
1459    
1460    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1461        custom one, because of the following reported problem in Windows:
1462    
1463          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1464              under Win32.
1465          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1466              therefore missing the function definition.
1467          - The compiler thus generates a "C" signature for the test function.
1468          - The linker fails to find the "C" function.
1469          - PCRE fails to configure if asked to do so against libbz2.
1470    
1471    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1472        messages were output:
1473    
1474          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1475          rerunning libtoolize, to keep the correct libtool macros in-tree.
1476          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1477    
1478        I have done both of these things.
1479    
1480    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1481        most of the time, it *can* run out if it is given a pattern that contains a
1482        runaway infinite recursion. I updated the discussion in the pcrestack man
1483        page.
1484    
1485    13. Now that we have gone to the x.xx style of version numbers, the minor
1486        version may start with zero. Using 08 or 09 is a bad idea because users
1487        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1488        interpreted as invalid octal numbers. I've updated the previous comment in
1489        configure.ac, and also added a check that gives an error if 08 or 09 are
1490        used.
1491    
1492    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1493        causing partial matching to fail when the end of the subject matched \W
1494        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1495    
1496    15. There were some discrepancies between the declarations in pcre_internal.h
1497        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1498        their definitions. The declarations used "const uschar *" and the
1499        definitions used USPTR. Even though USPTR is normally defined as "const
1500        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1501        reported that: "This difference in casting confuses some C++ compilers, for
1502        example, SunCC recognizes above declarations as different functions and
1503        generates broken code for hbpcre." I have changed the declarations to use
1504        USPTR.
1505    
1506    16. GNU libtool is named differently on some systems. The autogen.sh script now
1507        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1508        (FreeBSD).
1509    
1510    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1511        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1512        comment: "Figure out how to create a longlong from a string: strtoll and
1513        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1514        instance, but it only takes 2 args instead of 3!"
1515    
1516    18. A subtle bug concerned with back references has been fixed by a change of
1517        specification, with a corresponding code fix. A pattern such as
1518        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1519        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1520        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1521        same bug. Such groups have to be quantified to be useful, or contained
1522        inside another quantified group. (If there's no repetition, the reference
1523        can never match.) The problem arises because, having left the group and
1524        moved on to the rest of the pattern, a later failure that backtracks into
1525        the group uses the captured value from the final iteration of the group
1526        rather than the correct earlier one. I have fixed this in PCRE by forcing
1527        any group that contains a reference to itself to be an atomic group; that
1528        is, there cannot be any backtracking into it once it has completed. This is
1529        similar to recursive and subroutine calls.
1530    
1531    
1532    Version 8.00 19-Oct-09
1533    ----------------------
1534    
1535    1.  The table for translating pcre_compile() error codes into POSIX error codes
1536        was out-of-date, and there was no check on the pcre_compile() error code
1537        being within the table. This could lead to an OK return being given in
1538        error.
1539    
1540    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1541        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1542        in a Windows environment.
1543    
1544    3.  The pcregrep --count option prints the count for each file even when it is
1545        zero, as does GNU grep. However, pcregrep was also printing all files when
1546        --files-with-matches was added. Now, when both options are given, it prints
1547        counts only for those files that have at least one match. (GNU grep just
1548        prints the file name in this circumstance, but including the count seems
1549        more useful - otherwise, why use --count?) Also ensured that the
1550        combination -clh just lists non-zero counts, with no names.
1551    
1552    4.  The long form of the pcregrep -F option was incorrectly implemented as
1553        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1554        but it seems right to fix it, and I didn't think it was worth preserving
1555        the old behaviour.
1556    
1557    5.  The command line items --regex=pattern and --regexp=pattern were not
1558        recognized by pcregrep, which required --regex pattern or --regexp pattern
1559        (with a space rather than an '='). The man page documented the '=' forms,
1560        which are compatible with GNU grep; these now work.
1561    
1562    6.  No libpcreposix.pc file was created for pkg-config; there was just
1563        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1564    
1565    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1566        when UCP support is not needed, by modifying the Python script that
1567        generates it from Unicode data files. This should not matter if the module
1568        is correctly used as a library, but I received one complaint about 50K of
1569        unwanted data. My guess is that the person linked everything into his
1570        program rather than using a library. Anyway, it does no harm.
1571    
1572    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1573        was a minimum greater than 1 for a wide character in a possessive
1574        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1575        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1576        character. Chaos in the form of incorrect output or a compiling loop could
1577        result.
1578    
1579    9.  The restrictions on what a pattern can contain when partial matching is
1580        requested for pcre_exec() have been removed. All patterns can now be
1581        partially matched by this function. In addition, if there are at least two
1582        slots in the offset vector, the offset of the earliest inspected character
1583        for the match and the offset of the end of the subject are set in them when
1584        PCRE_ERROR_PARTIAL is returned.
1585    
1586    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1587        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1588        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1589        and may be more useful for multi-segment matching.
1590    
1591    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1592        used to be given if ever the end of the subject was reached; now it is
1593        given only if matching could not proceed because another character was
1594        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1595        string "Z", which now yields "no match" instead of "partial match". In the
1596        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1597        final character ended with (*FAIL).
1598    
1599    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1600        if the pattern had a "must contain" character that was already found in the
1601        earlier partial match, unless partial matching was again requested. For
1602        example, with the pattern /dog.(body)?/, the "must contain" character is
1603        "g". If the first part-match was for the string "dog", restarting with
1604        "sbody" failed. This bug has been fixed.
1605    
1606    13. The string returned by pcre_dfa_exec() after a partial match has been
1607        changed so that it starts at the first inspected character rather than the
1608        first character of the match. This makes a difference only if the pattern
1609        starts with a lookbehind assertion or \b or \B (\K is not supported by
1610        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1611        matching functions compatible, and I think it's the right thing to do.
1612    
1613    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1614        so that the demonstration program is easily available in environments where
1615        PCRE has not been installed from source.
1616    
1617    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1618        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1619        library.
1620    
1621    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1622        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1623        is not the first non-POSIX option to be added. Clearly some people find
1624        these options useful.
1625    
1626    17. If a caller to the POSIX matching function regexec() passes a non-zero
1627        value for nmatch with a NULL value for pmatch, the value of
1628        nmatch is forced to zero.
1629    
1630    18. RunGrepTest did not have a test for the availability of the -u option of
1631        the diff command, as RunTest does. It now checks in the same way as
1632        RunTest, and also checks for the -b option.
1633    
1634    19. If an odd number of negated classes containing just a single character
1635        interposed, within parentheses, between a forward reference to a named
1636        subpattern and the definition of the subpattern, compilation crashed with
1637        an internal error, complaining that it could not find the referenced
1638        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1639        [The bug was that it was starting one character too far in when skipping
1640        over the character class, thus treating the ] as data rather than
1641        terminating the class. This meant it could skip too much.]
1642    
1643    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1644        /g option in pcretest when the pattern contains \K, which makes it possible
1645        to have an empty string match not at the start, even when the pattern is
1646        anchored. Updated pcretest and pcredemo to use this option.
1647    
1648    21. If the maximum number of capturing subpatterns in a recursion was greater
1649        than the maximum at the outer level, the higher number was returned, but
1650        with unset values at the outer level. The correct (outer level) value is
1651        now given.
1652    
1653    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1654        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1655        make it do so. The string so far is captured, making this feature
1656        compatible with Perl.
1657    
1658    23. The tests have been re-organized, adding tests 11 and 12, to make it
1659        possible to check the Perl 5.10 features against Perl 5.10.
1660    
1661    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1662        pattern matches a fixed length string. PCRE did not allow this; now it
1663        does. Neither allows recursion.
1664    
1665    25. I finally figured out how to implement a request to provide the minimum
1666        length of subject string that was needed in order to match a given pattern.
1667        (It was back references and recursion that I had previously got hung up
1668        on.) This code has now been added to pcre_study(); it finds a lower bound
1669        to the length of subject needed. It is not necessarily the greatest lower
1670        bound, but using it to avoid searching strings that are too short does give
1671        some useful speed-ups. The value is available to calling programs via
1672        pcre_fullinfo().
1673    
1674    26. While implementing 25, I discovered to my embarrassment that pcretest had
1675        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1676        study optimizations had never been tested with that matching function.
1677        Oops. What is worse, even when it was passed study data, there was a bug in
1678        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1679        were also very few tests of studied patterns with pcre_dfa_exec().
1680    
1681    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1682        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1683        on the other side of the coin, they are no longer allowed to have different
1684        names, because these cannot be distinguished in PCRE, and this has caused
1685        confusion. (This is a difference from Perl.)
1686    
1687    28. When duplicate subpattern names are present (necessarily with different
1688        numbers, as required by 27 above), and a test is made by name in a
1689        conditional pattern, either for a subpattern having been matched, or for
1690        recursion in such a pattern, all the associated numbered subpatterns are
1691        tested, and the overall condition is true if the condition is true for any
1692        one of them. This is the way Perl works, and is also more like the way
1693        testing by number works.
1694    
1695    
1696    Version 7.9 11-Apr-09
1697    ---------------------
1698    
1699    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1700        (pcretest), all targets were linked against these libraries. This included
1701        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1702        libraries. This caused unwanted dependencies to be created. This problem
1703        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1704        pcretest is linked with readline.
1705    
1706    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1707        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1708        moved outside it again, because FALSE and TRUE are already defined in AIX,
1709        but BOOL is not.
1710    
1711    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1712        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1713    
1714    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1715        hyphens) following file names and line numbers when outputting matching
1716        lines. This is not true; no spaces are inserted. I have also clarified the
1717        wording for the --colour (or --color) option.
1718    
1719    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1720        was not coloured; this is different to GNU grep, so I have changed it to be
1721        the same.
1722    
1723    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1724        each matching line was coloured. Now it goes on to look for further matches
1725        of any of the test patterns, which is the same behaviour as GNU grep.
1726    
1727    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1728        doesn't make sense to accept an empty string match in pcregrep, so I have
1729        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1730        seems to be how GNU grep behaves. [But see later change 40 for release
1731        8.33.]
1732    
1733    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1734        start or after a newline", because the conditional assertion was not being
1735        correctly handled. The rule now is that both the assertion and what follows
1736        in the first alternative must satisfy the test.
1737    
1738    9.  If auto-callout was enabled in a pattern with a conditional group whose
1739        condition was an assertion, PCRE could crash during matching, both with
1740        pcre_exec() and pcre_dfa_exec().
1741    
1742    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1743        used for matching.
1744    
1745    11. Unicode property support in character classes was not working for
1746        characters (bytes) greater than 127 when not in UTF-8 mode.
1747    
1748    12. Added the -M command line option to pcretest.
1749    
1750    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1751    
1752    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1753    
1754    16. Added comments and documentation about mis-use of no_arg in the C++
1755        wrapper.
1756    
1757    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1758        from Martin Jerabek that uses macro names for all relevant character and
1759        string constants.
1760    
1761    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1762        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1763        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1764        these, but not everybody uses configure.
1765    
1766    19. A conditional group that had only one branch was not being correctly
1767        recognized as an item that could match an empty string. This meant that an
1768        enclosing group might also not be so recognized, causing infinite looping
1769        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1770        with the subject "ab", where knowledge that the repeated group can match
1771        nothing is needed in order to break the loop.
1772    
1773    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1774        exec(), but without supplying a callout function, matching went wrong.
1775    
1776    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1777        leak if the size of the offset vector was greater than 30. When the vector
1778        is smaller, the saved offsets during recursion go onto a local stack
1779        vector, but for larger vectors malloc() is used. It was failing to free
1780        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1781        error, in fact).
1782    
1783    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1784        heapframe that is used only when UTF-8 support is enabled. This caused no
1785        problem, but was untidy.
1786    
1787    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1788        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1789        included within another project.
1790    
1791    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1792        slightly modified by me:
1793    
1794          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1795              not building pcregrep.
1796    
1797          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1798              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1799    
1800    25. Forward references, both numeric and by name, in patterns that made use of
1801        duplicate group numbers, could behave incorrectly or give incorrect errors,
1802        because when scanning forward to find the reference group, PCRE was not
1803        taking into account the duplicate group numbers. A pattern such as
1804        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1805    
1806    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1807        the feature of a custom pointer more persuasive (as requested by a user).
1808    
1809    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1810        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1811        pre-defined.
1812    
1813    28. Added support for (*UTF8) at the start of a pattern.
1814    
1815    29. Arrange for flags added by the "release type" setting in CMake to be shown
1816        in the configuration summary.
1817    
1818    
1819    Version 7.8 05-Sep-08
1820    ---------------------
1821    
1822    1.  Replaced UCP searching code with optimized version as implemented for Ad
1823        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1824        stage table and inline lookup instead of a function, giving speed ups of 2
1825        to 5 times on some simple patterns that I tested. Permission was given to
1826        distribute the MultiStage2.py script that generates the tables (it's not in
1827        the tarball, but is in the Subversion repository).
1828    
1829    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1830        scripts.
1831    
1832    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1833        a group with a zero qualifier. The result of the study could be incorrect,
1834        or the function might crash, depending on the pattern.
1835    
1836    4.  Caseless matching was not working for non-ASCII characters in back
1837        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1838        It now works when Unicode Property Support is available.
1839    
1840    5.  In pcretest, an escape such as \x{de} in the data was always generating
1841        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1842        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1843        truncation.
1844    
1845    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1846    
1847    7.  Added two (int) casts to pcregrep when printing the difference of two
1848        pointers, in case they are 64-bit values.
1849    
1850    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1851        test 2 if it fails.
1852    
1853    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1854        and a #define of that name to empty if it is not externally set. This is to
1855        allow users of MSVC to set it if necessary.
1856    
1857    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1858        the convenience functions in the pcre_get.c source file.
1859    
1860    11. An option change at the start of a pattern that had top-level alternatives
1861        could cause overwriting and/or a crash. This command provoked a crash in
1862        some environments:
1863    
1864          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1865    
1866        This potential security problem was recorded as CVE-2008-2371.
1867    
1868    12. For a pattern where the match had to start at the beginning or immediately
1869        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1870        pcre_dfa_exec() could read past the end of the passed subject if there was
1871        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1872        pcretest so that it places the subject at the end of its malloc-ed buffer.
1873    
1874    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1875        exec() might read past the end of the data buffer in UTF-8 mode.
1876    
1877    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1878        the data contained the byte 0x85 as part of a UTF-8 character within its
1879        first line. This applied both to normal and DFA matching.
1880    
1881    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1882        /^[^d]*?$/8 failed to match "abc".
1883    
1884    16. Added a missing copyright notice to pcrecpp_internal.h.
1885    
1886    17. Make it more clear in the documentation that values returned from
1887        pcre_exec() in ovector are byte offsets, not character counts.
1888    
1889    18. Tidied a few places to stop certain compilers from issuing warnings.
1890    
1891    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1892        supplied by Stefan Weber. I made a further small update for 7.8 because
1893        there is a change of source arrangements: the pcre_searchfuncs.c module is
1894        replaced by pcre_ucd.c.
1895    
1896    
1897    Version 7.7 07-May-08
1898    ---------------------
1899    
1900    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1901        a string to a long long, pretend we don't even have a long long." This is
1902        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1903    
1904    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1905        pre-7.6 versions, which defined a global no_arg variable instead of putting
1906        it in the RE class. (See also #8 below.)
1907    
1908    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1909        Lopes.
1910    
1911    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1912    
1913        (1) The include/exclude patterns were being applied to the whole pathnames
1914            of files, instead of just to the final components.
1915    
1916        (2) If there was more than one level of directory, the subdirectories were
1917            skipped unless they satisfied the include/exclude conditions. This is
1918            inconsistent with GNU grep (and could even be seen as contrary to the
1919            pcregrep specification - which I improved to make it absolutely clear).
1920            The action now is always to scan all levels of directory, and just
1921            apply the include/exclude patterns to regular files.
1922    
1923    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1924        --exclude_dir in the tests to avoid scanning .svn directories.
1925    
1926    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1927        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1928        doesn't support NULs in patterns.
1929    
1930    7.  Added some missing "const"s to declarations of static tables in
1931        pcre_compile.c and pcre_dfa_exec.c.
1932    
1933    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1934        caused by fix #2  above. (Subsequently also a second patch to fix the
1935        first patch. And a third patch - this was a messy problem.)
1936    
1937    9.  Applied Craig's patch to remove the use of push_back().
1938    
1939    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1940        matching function regexec().
1941    
1942    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1943        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1944        references. PCRE supports relative numbers with this syntax (I don't think
1945        Oniguruma does).
1946    
1947    12. Previously, a group with a zero repeat such as (...){0} was completely
1948        omitted from the compiled regex. However, this means that if the group
1949        was called as a subroutine from elsewhere in the pattern, things went wrong
1950        (an internal error was given). Such groups are now left in the compiled
1951        pattern, with a new opcode that causes them to be skipped at execution
1952        time.
1953    
1954    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1955        to the way PCRE behaves:
1956    
1957        (a) A lone ] character is dis-allowed (Perl treats it as data).
1958    
1959        (b) A back reference to an unmatched subpattern matches an empty string
1960            (Perl fails the current match path).
1961    
1962        (c) A data ] in a character class must be notated as \] because if the
1963            first data character in a class is ], it defines an empty class. (In
1964            Perl it is not possible to have an empty class.) The empty class []
1965            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1966            The negative empty class [^] matches any one character, independently
1967            of the DOTALL setting.
1968    
1969    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1970        non-existent subpattern following a character class starting with ']' and
1971        containing () gave an internal compiling error instead of "reference to
1972        non-existent subpattern". Fortunately, when the pattern did exist, the
1973        compiled code was correct. (When scanning forwards to check for the
1974        existence of the subpattern, it was treating the data ']' as terminating
1975        the class, so got the count wrong. When actually compiling, the reference
1976        was subsequently set up correctly.)
1977    
1978    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1979        it was being rejected as not supported by pcre_dfa_exec(), even though
1980        other assertions are supported. I have made pcre_dfa_exec() support
1981        (*FAIL).
1982    
1983    16. The implementation of 13c above involved the invention of a new opcode,
1984        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1985        cannot be changed at match time, I realized I could make a small
1986        improvement to matching performance by compiling OP_ALLANY instead of
1987        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1988        on the OP_ANY path.
1989    
1990    17. Compiling pcretest on Windows with readline support failed without the
1991        following two fixes: (1) Make the unistd.h include conditional on
1992        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1993    
1994    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1995        ncurses library to be included for pcretest when ReadLine support is
1996        requested, but also to allow for it to be overridden. This patch came from
1997        Daniel Bergström.
1998    
1999    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2000        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2001        any errors with the current Unicode tables. Thanks to Peter Kankowski for
2002        spotting this.
2003    
2004    
2005    Version 7.6 28-Jan-08
2006    ---------------------
2007    
2008    1.  A character class containing a very large number of characters with
2009        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2010        overflow.
2011    
2012    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
2013        HAVE_LONG_LONG is not defined.
2014    
2015    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
2016        bring them up to date and include new features. This patch includes:
2017    
2018        - Fixed PH's badly added libz and libbz2 support.
2019        - Fixed a problem with static linking.
2020        - Added pcredemo. [But later removed - see 7 below.]
2021        - Fixed dftables problem and added an option.
2022        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2023            HAVE_LONG_LONG.
2024        - Added readline support for pcretest.
2025        - Added an listing of the option settings after cmake has run.
2026    
2027    4.  A user submitted a patch to Makefile that makes it easy to create
2028        "pcre.dll" under mingw when using Configure/Make. I added stuff to
2029        Makefile.am that cause it to include this special target, without
2030        affecting anything else. Note that the same mingw target plus all
2031        the other distribution libraries and programs are now supported
2032        when configuring with CMake (see 6 below) instead of with
2033        Configure/Make.
2034    
2035    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2036        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2037        exported in the Windows port". It has not yet been confirmed that the patch
2038        solves the problem, but it does no harm.
2039    
2040    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2041        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2042        with CMake, and also correct the comment about stack recursion.
2043    
2044    7.  Remove the automatic building of pcredemo from the ./configure system and
2045        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2046        of a program that users should build themselves after PCRE is installed, so
2047        building it automatically is not really right. What is more, it gave
2048        trouble in some build environments.
2049    
2050    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
2051    
2052    
2053    Version 7.5 10-Jan-08
2054    ---------------------
2055    
2056    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
2057        values in parens when parsing an RE using the C++ wrapper."
2058    
2059    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
2060        Characters greater than 255 were excluded from the class instead of being
2061        included.
2062    
2063    3.  The same bug as (2) above applied to negated POSIX classes such as
2064        [:^space:].
2065    
2066    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2067        defined or documented. It seems to have been a typo for PCRE_STATIC, so
2068        I have changed it.
2069    
2070    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
2071        first named subpattern) and a construct such as (?&a) would reference the
2072        first named subpattern whose name started with "a" (in other words, the
2073        length check was missing). Both these problems are fixed. "Subpattern name
2074        expected" is now given for (?&) (a zero-length name), and this patch also
2075        makes it give the same error for \k'' (previously it complained that that
2076        was a reference to a non-existent subpattern).
2077    
2078    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
2079        this is right because (?- can be followed by option settings as well as by
2080        digits. I have, however, made the messages clearer.
2081    
2082    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2083        than the number used in the conditional) now cause a compile-time error.
2084        This is actually not compatible with Perl, which accepts such patterns, but
2085        treats the conditional as always being FALSE (as PCRE used to), but it
2086        seems to me that giving a diagnostic is better.
2087    
2088    8.  Change "alphameric" to the more common word "alphanumeric" in comments
2089        and messages.
2090    
2091    9.  Fix two occurrences of "backslash" in comments that should have been
2092        "backspace".
2093    
2094    10. Remove two redundant lines of code that can never be obeyed (their function
2095        was moved elsewhere).
2096    
2097    11. The program that makes PCRE's Unicode character property table had a bug
2098        which caused it to generate incorrect table entries for sequences of
2099        characters that have the same character type, but are in different scripts.
2100        It amalgamated them into a single range, with the script of the first of
2101        them. In other words, some characters were in the wrong script. There were
2102        thirteen such cases, affecting characters in the following ranges:
2103    
2104          U+002b0 - U+002c1
2105          U+0060c - U+0060d
2106          U+0061e - U+00612
2107          U+0064b - U+0065e
2108          U+0074d - U+0076d
2109          U+01800 - U+01805
2110          U+01d00 - U+01d77
2111          U+01d9b - U+01dbf
2112          U+0200b - U+0200f
2113          U+030fc - U+030fe
2114          U+03260 - U+0327f
2115          U+0fb46 - U+0fbb1
2116          U+10450 - U+1049d
2117    
2118    12. The -o option (show only the matching part of a line) for pcregrep was not
2119        compatible with GNU grep in that, if there was more than one match in a
2120        line, it showed only the first of them. It now behaves in the same way as
2121        GNU grep.
2122    
2123    13. If the -o and -v options were combined for pcregrep, it printed a blank
2124        line for every non-matching line. GNU grep prints nothing, and pcregrep now
2125        does the same. The return code can be used to tell if there were any
2126        non-matching lines.
2127    
2128    14. Added --file-offsets and --line-offsets to pcregrep.
2129    
2130    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2131        infinitely looping recursion. The bug was that positive lookaheads were not
2132        being skipped when checking for a possible empty match (negative lookaheads
2133        and both kinds of lookbehind were skipped).
2134    
2135    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2136        inclusion of <windows.h> to before rather than after the definition of
2137        INVALID_FILE_ATTRIBUTES (patch from David Byron).
2138    
2139    17. Specifying a possessive quantifier with a specific limit for a Unicode
2140        character property caused pcre_compile() to compile bad code, which led at
2141        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2142        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2143        caused the error; without that there was no problem.
2144    
2145    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2146    
2147    19. Added --enable-pcretest-libreadline.
2148    
2149    20. In pcrecpp.cc, the variable 'count' was incremented twice in
2150        RE::GlobalReplace(). As a result, the number of replacements returned was
2151        double what it should be. I removed one of the increments, but Craig sent a
2152        later patch that removed the other one (the right fix) and added unit tests
2153        that check the return values (which was not done before).
2154    
2155    21. Several CMake things:
2156    
2157        (1) Arranged that, when cmake is used on Unix, the libraries end up with
2158            the names libpcre and libpcreposix, not just pcre and pcreposix.
2159    
2160        (2) The above change means that pcretest and pcregrep are now correctly
2161            linked with the newly-built libraries, not previously installed ones.
2162    
2163        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2164    
2165    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2166        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2167        UTF-8 newline character). The key issue is that the pattern starts .*;
2168        this means that the match must be either at the beginning, or after a
2169        newline. The bug was in the code for advancing after a failed match and
2170        checking that the new position followed a newline. It was not taking
2171        account of UTF-8 characters correctly.
2172    
2173    23. PCRE was behaving differently from Perl in the way it recognized POSIX
2174        character classes. PCRE was not treating the sequence [:...:] as a
2175        character class unless the ... were all letters. Perl, however, seems to
2176        allow any characters between [: and :], though of course it rejects as
2177        unknown any "names" that contain non-letters, because all the known class
2178        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2179        for example, whereas PCRE did not - it did not recognize a POSIX character
2180        class. This seemed a bit dangerous, so the code has been changed to be
2181        closer to Perl. The behaviour is not identical to Perl, because PCRE will
2182        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2183        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2184        Perl does, and where it didn't before.
2185    
2186    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2187        Windows environments %n is disabled by default.
2188    
2189    
2190    Version 7.4 21-Sep-07
2191    ---------------------
2192    
2193    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
2194        means that a class such as [\s] counted as "explicit reference to CR or
2195        LF". That isn't really right - the whole point of the change was to try to
2196        help when there was an actual mention of one of the two characters. So now
2197        the change happens only if \r or \n (or a literal CR or LF) character is
2198        encountered.
2199    
2200    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
2201        of both had grown to the point where there were only 3 bits left.
2202        Fortunately, there was spare space in the data structure, and so I have
2203        moved the internal flags into a new 16-bit field to free up more option
2204        bits.
2205    
2206    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2207        but did not set the internal JCHANGED flag - either of these is enough to
2208        control the way the "get" function works - but the PCRE_INFO_JCHANGED
2209        facility is supposed to tell if (?J) was ever used, so now (?J) at the
2210        start sets both bits.
2211    
2212    4.  Added options (at build time, compile time, exec time) to change \R from
2213        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2214    
2215    5.  doc/pcresyntax.html was missing from the distribution.
2216    
2217    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2218        compatibility, even though it is no longer used.
2219    
2220    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2221        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2222        windows.h file is present (where different names are used). [This was
2223        reversed later after testing - see 16 below.]
2224    
2225    8.  Changed all #include <config.h> to #include "config.h". There were also
2226        some further <pcre.h> cases that I changed to "pcre.h".
2227    
2228    9.  When pcregrep was used with the --colour option, it missed the line ending
2229        sequence off the lines that it output.
2230    
2231    10. It was pointed out to me that arrays of string pointers cause lots of
2232        relocations when a shared library is dynamically loaded. A technique of
2233        using a single long string with a table of offsets can drastically reduce
2234        these. I have refactored PCRE in four places to do this. The result is
2235        dramatic:
2236    
2237          Originally:                          290
2238          After changing UCP table:            187
2239          After changing error message table:   43
2240          After changing table of "verbs"       36
2241          After changing table of Posix names   22
2242    
2243        Thanks to the folks working on Gregex for glib for this insight.
2244    
2245    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2246        unicode-properties was also set.
2247    
2248    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2249    
2250    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2251        checked only for CRLF.
2252    
2253    14. Added casts to pcretest.c to avoid compiler warnings.
2254    
2255    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2256    
2257    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2258        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2259        entirely. This removes changes made in 7 above.
2260    
2261    17. The CMake files have been updated, and there is now more information about
2262        building with CMake in the NON-UNIX-USE document.
2263    
2264    
2265    Version 7.3 28-Aug-07
2266  ---------------------  ---------------------
2267    
2268   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 29  Version 7.3 05-Jul-07 Line 2290  Version 7.3 05-Jul-07
2290   4. Debugging: adjusted the names of opcodes for different kinds of parentheses   4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2291      in debug output.      in debug output.
2292    
2293   5. Arrange to use "%I64d" instead of "%lld" for long printing in the pcrecpp   5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2294      unittest when running under MinGW.      long printing in the pcrecpp unittest when running under MinGW.
2295    
2296   6. ESC_K was left out of the EBCDIC table.   6. ESC_K was left out of the EBCDIC table.
2297    
# Line 53  Version 7.3 05-Jul-07 Line 2314  Version 7.3 05-Jul-07
2314      pcreposix and pcrecpp parts of the library. These were overlooked when this      pcreposix and pcrecpp parts of the library. These were overlooked when this
2315      problem was solved for the main library.      problem was solved for the main library.
2316    
2317     9. There were some crude static tests to avoid integer overflow when computing
2318        the size of patterns that contain repeated groups with explicit upper
2319        limits. As the maximum quantifier is 65535, the maximum group length was
2320        set at 30,000 so that the product of these two numbers did not overflow a
2321        32-bit integer. However, it turns out that people want to use groups that
2322        are longer than 30,000 bytes (though not repeat them that many times).
2323        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2324        made it possible to implement the integer overflow checks in a much more
2325        dynamic way, which I have now done. The artificial limitation on group
2326        length has been removed - we now have only the limit on the total length of
2327        the compiled pattern, which depends on the LINK_SIZE setting.
2328    
2329    10. Fixed a bug in the documentation for get/copy named substring when
2330        duplicate names are permitted. If none of the named substrings are set, the
2331        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2332        empty string.
2333    
2334    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2335        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2336        because the ] is interpreted as the first data character and the
2337        terminating ] is not found. PCRE has been made compatible with Perl in this
2338        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2339        cause memory overwriting.
2340    
2341    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2342        string has been matched (to stop an infinite loop). It was not recognizing
2343        a conditional subpattern that could match an empty string if that
2344        subpattern was within another subpattern. For example, it looped when
2345        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
2346        condition was not nested. This bug has been fixed.
2347    
2348    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2349        past the start of the subject in the presence of bytes with the top bit
2350        set, for example "\x8aBCD".
2351    
2352    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2353        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2354    
2355    14. Optimized (?!) to (*FAIL).
2356    
2357    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2358        This restricts code points to be within the range 0 to 0x10FFFF, excluding
2359        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2360        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2361        does: it's just the validity check that is more restrictive.
2362    
2363    16. Inserted checks for integer overflows during escape sequence (backslash)
2364        processing, and also fixed erroneous offset values for syntax errors during
2365        backslash processing.
2366    
2367    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2368        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2369    
2370    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2371        caused an overrun.
2372    
2373    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2374        something other than just ASCII characters) inside a group that had an
2375        unlimited repeat caused a loop at compile time (while checking to see
2376        whether the group could match an empty string).
2377    
2378    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2379        [\P{Any}] did so. (Error in the code for printing property names.)
2380    
2381    21. An orphan \E inside a character class could cause a crash.
2382    
2383    22. A repeated capturing bracket such as (A)? could cause a wild memory
2384        reference during compilation.
2385    
2386    23. There are several functions in pcre_compile() that scan along a compiled
2387        expression for various reasons (e.g. to see if it's fixed length for look
2388        behind). There were bugs in these functions when a repeated \p or \P was
2389        present in the pattern. These operators have additional parameters compared
2390        with \d, etc, and these were not being taken into account when moving along
2391        the compiled data. Specifically:
2392    
2393        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2394            length.
2395    
2396        (b) An item such as \pL+ within a repeated group could cause crashes or
2397            loops.
2398    
2399        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2400            "reference to non-existent subpattern" error.
2401    
2402        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2403    
2404    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2405        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2406    
2407    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2408    
2409    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2410        character were causing crashes (broken optimization).
2411    
2412    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2413        \p or \P) caused a compile-time loop.
2414    
2415    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2416        break. For example, the unstudied pattern [\r\n]A does not match the string
2417        "\r\nA" because change 7.0/46 below moves the current point on by two
2418        characters after failing to match at the start. However, the pattern \nA
2419        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2420        the same is true. There doesn't seem any very clean way out of this, but
2421        what I have chosen to do makes the common cases work: PCRE now takes note
2422        of whether there can be an explicit match for \r or \n anywhere in the
2423        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2424        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2425        pattern has explicit CR or LF references.
2426    
2427    29. Added (*CR) etc for changing newline setting at start of pattern.
2428    
2429    
2430  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
2431  ---------------------  ---------------------

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