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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.35-RC1 xx-xxxx-201x
5    -----------------------------
6    
7    1.  A new flag is set, when property checks are present in an XCLASS.
8        When this flag is not set, PCRE can perform certain optimizations
9        such as studying these XCLASS-es.
10    
11    2.  The auto-possessification of character sets were improved: a normal
12        and an extended character set can be compared now. Furthermore
13        the JIT compiler optimizes more character set checks.
14    
15    3.  Got rid of some compiler warnings for potentially uninitialized variables
16        that show up only when compiled with -O2.
17    
18    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
19        of a match later then the end of the match. The pcretest program was not
20        handling the case sensibly - it was outputting from the start to the next
21        binary zero. It now reports this situation in a message, and outputs the
22        text from the end to the start.
23    
24    5.  Fast forward search is improved in JIT. Instead of the first three
25        characters, any three characters with fixed position can be searched.
26        Search order: first, last, middle.
27    
28    6.  Improve character range checks in JIT. Characters are read by an inprecise
29        function now, which returns with an unknown value if the character code is
30        above a certain treshold (e.g: 256). The only limitation is that the value
31        must be bigger than the treshold as well. This function is useful, when
32        the characters above the treshold are handled in the same way.
33    
34    7.  The macros whose names start with RAWUCHAR are placeholders for a future
35        mode in which only the bottom 21 bits of 32-bit data items are used. To
36        make this more memorable for those maintaining the code, the names have
37        been changed to start with UCHAR21, and an extensive comment has been added
38        to their definition.
39    
40    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
41        to the export list in Makefile.am (they were accidentally omitted from the
42        8.34 tarball).
43    
44    9.  The informational output from pcretest used the phrase "starting byte set"
45        which is inappropriate for the 16-bit and 32-bit libraries. As the output
46        for "first char" and "need char" really means "non-UTF-char", I've changed
47        "byte" to "char", and slightly reworded the output. The documentation about
48        these values has also been (I hope) clarified.
49    
50    
51    Version 8.34 15-December-2013
52    -----------------------------
53    
54    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
55        executable memory. Patch inspired by Carsten Klein.
56    
57    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
58        this macro is never tested and has no effect, because the work to support
59        coverage involves only compiling and linking options and special targets in
60        the Makefile. The comment in config.h implied that defining the macro would
61        enable coverage support, which is totally false. There was also support for
62        setting this macro in the CMake files (my fault, I just copied it from
63        configure). SUPPORT_GCOV has now been removed.
64    
65    3.  Make a small performance improvement in strlen16() and strlen32() in
66        pcretest.
67    
68    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
69        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
70        these cases). There was also one in pcretest.c.
71    
72    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
73    
74    6.  In UTF mode, the code for checking whether a group could match an empty
75        string (which is used for indefinitely repeated groups to allow for
76        breaking an infinite loop) was broken when the group contained a repeated
77        negated single-character class with a character that occupied more than one
78        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
79        UTF-8 mode). The effect was undefined: the group might or might not be
80        deemed as matching an empty string, or the program might have crashed.
81    
82    7.  The code for checking whether a group could match an empty string was not
83        recognizing that \h, \H, \v, \V, and \R must match a character.
84    
85    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
86        an empty string. If it can, pcretest shows this in its information output.
87    
88    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
89        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
90        matched by pcre_exec() without using JIT:
91    
92        (a) If the rest of the pattern did not match after a maximal run of
93            grapheme clusters, the code for backing up to try with fewer of them
94            did not always back up over a full grapheme when characters that do not
95            have the modifier quality were involved, e.g. Hangul syllables.
96    
97        (b) If the match point in a subject started with modifier character, and
98            there was no match, the code could incorrectly back up beyond the match
99            point, and potentially beyond the first character in the subject,
100            leading to a segfault or an incorrect match result.
101    
102    10. A conditional group with an assertion condition could lead to PCRE
103        recording an incorrect first data item for a match if no other first data
104        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
105        first data item, and therefore matched "ca" after "c" instead of at the
106        start.
107    
108    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
109        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
110    
111    12. The source of pcregrep now includes z/OS-specific code so that it can be
112        compiled for z/OS as part of the special z/OS distribution.
113    
114    13. Added the -T and -TM options to pcretest.
115    
116    14. The code in pcre_compile.c for creating the table of named capturing groups
117        has been refactored. Instead of creating the table dynamically during the
118        actual compiling pass, the information is remembered during the pre-compile
119        pass (on the stack unless there are more than 20 named groups, in which
120        case malloc() is used) and the whole table is created before the actual
121        compile happens. This has simplified the code (it is now nearly 150 lines
122        shorter) and prepared the way for better handling of references to groups
123        with duplicate names.
124    
125    15. A back reference to a named subpattern when there is more than one of the
126        same name now checks them in the order in which they appear in the pattern.
127        The first one that is set is used for the reference. Previously only the
128        first one was inspected. This change makes PCRE more compatible with Perl.
129    
130    16. Unicode character properties were updated from Unicode 6.3.0.
131    
132    17. The compile-time code for auto-possessification has been refactored, based
133        on a patch by Zoltan Herczeg. It now happens after instead of during
134        compilation. The code is cleaner, and more cases are handled. The option
135        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
136        options in pcretest are provided to set it. It can also be set by
137        (*NO_AUTO_POSSESS) at the start of a pattern.
138    
139    18. The character VT has been added to the default ("C" locale) set of
140        characters that match \s and are generally treated as white space,
141        following this same change in Perl 5.18. There is now no difference between
142        "Perl space" and "POSIX space". Whether VT is treated as white space in
143        other locales depends on the locale.
144    
145    19. The code for checking named groups as conditions, either for being set or
146        for being recursed, has been refactored (this is related to 14 and 15
147        above). Processing unduplicated named groups should now be as fast at
148        numerical groups, and processing duplicated groups should be faster than
149        before.
150    
151    20. Two patches to the CMake build system, by Alexander Barkov:
152    
153          (1) Replace the "source" command by "." in CMakeLists.txt because
154              "source" is a bash-ism.
155    
156          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
157              without these the CMake build does not work on Solaris.
158    
159    21. Perl has changed its handling of \8 and \9. If there is no previously
160        encountered capturing group of those numbers, they are treated as the
161        literal characters 8 and 9 instead of a binary zero followed by the
162        literals. PCRE now does the same.
163    
164    22. Following Perl, added \o{} to specify codepoints in octal, making it
165        possible to specify values greater than 0777 and also making them
166        unambiguous.
167    
168    23. Perl now gives an error for missing closing braces after \x{... instead of
169        treating the string as literal. PCRE now does the same.
170    
171    24. RunTest used to grumble if an inappropriate test was selected explicitly,
172        but just skip it when running all tests. This make it awkward to run ranges
173        of tests when one of them was inappropriate. Now it just skips any
174        inappropriate tests, as it always did when running all tests.
175    
176    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
177        character types such as \d or \w, too many callouts were inserted, and the
178        data that they returned was rubbish.
179    
180    26. In UCP mode, \s was not matching two of the characters that Perl matches,
181        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
182        were matched by \h. The code has now been refactored so that the lists of
183        the horizontal and vertical whitespace characters used for \h and \v (which
184        are defined only in one place) are now also used for \s.
185    
186    27. Add JIT support for the 64 bit TileGX architecture.
187        Patch by Jiong Wang (Tilera Corporation).
188    
189    28. Possessive quantifiers for classes (both explicit and automatically
190        generated) now use special opcodes instead of wrapping in ONCE brackets.
191    
192    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
193        (because it's meaningless), this was not happening when PCRE_CASELESS was
194        set. Not wrong, but inefficient.
195    
196    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
197        properties for \w, \d, etc) is present in a test regex. Otherwise if the
198        test contains no characters greater than 255, Perl doesn't realise it
199        should be using Unicode semantics.
200    
201    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
202        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
203        does in Unicode mode.
204    
205    32. Added the "forbid" facility to pcretest so that putting tests into the
206        wrong test files can sometimes be quickly detected.
207    
208    33. There is now a limit (default 250) on the depth of nesting of parentheses.
209        This limit is imposed to control the amount of system stack used at compile
210        time. It can be changed at build time by --with-parens-nest-limit=xxx or
211        the equivalent in CMake.
212    
213    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
214        errors. Perl warns for these when in warning mode, but PCRE has no facility
215        for giving warnings.
216    
217    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
218        However, this was not working for (?!) because it is optimized to (*FAIL),
219        for which PCRE does not allow quantifiers. The optimization is now disabled
220        when a quantifier follows (?!). I can't see any use for this, but it makes
221        things uniform.
222    
223    36. Perl no longer allows group names to start with digits, so I have made this
224        change also in PCRE. It simplifies the code a bit.
225    
226    37. In extended mode, Perl ignores spaces before a + that indicates a
227        possessive quantifier. PCRE allowed a space before the quantifier, but not
228        before the possessive +. It now does.
229    
230    38. The use of \K (reset reported match start) within a repeated possessive
231        group such as (a\Kb)*+ was not working.
232    
233    40. Document that the same character tables must be used at compile time and
234        run time, and that the facility to pass tables to pcre_exec() and
235        pcre_dfa_exec() is for use only with saved/restored patterns.
236    
237    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
238        features for Builds with MSVC:
239    
240        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
241           builds). The .rc files can be used to set FileDescription and many other
242           attributes.
243    
244        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
245           This allows higher-level build scripts which want .pdb files to avoid
246           hard-coding the exact files needed."
247    
248    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
249        mean "start of word" and "end of word", respectively, as a transition aid.
250    
251    43. A minimizing repeat of a class containing codepoints greater than 255 in
252        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
253        compiled to use the heap for recursion.
254    
255    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
256        is configured.
257    
258    
259    Version 8.33 28-May-2013
260    ------------------------
261    
262    1.  Added 'U' to some constants that are compared to unsigned integers, to
263        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
264        variables that are added to signed variables, to ensure the result is
265        signed and can be negated.
266    
267    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
268        CMake config files.
269    
270    3.  Revise the creation of config.h.generic so that all boolean macros are
271        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
272        overriding via -D on the command line possible.
273    
274    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
275        to unsigned int is reported to make a quite noticeable speed difference in
276        a specific Windows environment. Testing on Linux did also appear to show
277        some benefit (and it is clearly not harmful). Also fixed the definition of
278        Xop which should be unsigned.
279    
280    5.  Related to (4), changing the definition of the intermediate variable cc
281        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
282        improvements.
283    
284    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
285        unnecessary spaces.
286    
287    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
288        and later.
289    
290    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
291    
292    9.  Optimizing fast_forward_start_bits in JIT.
293    
294    10. Adding support for callouts in JIT, and fixing some issues revealed
295        during this work. Namely:
296    
297        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
298    
299        (b) Minimum length was not checked before the matching is started.
300    
301    11. The value of capture_last that is passed to callouts was incorrect in some
302        cases when there was a capture on one path that was subsequently abandoned
303        after a backtrack. Also, the capture_last value is now reset after a
304        recursion, since all captures are also reset in this case.
305    
306    12. The interpreter no longer returns the "too many substrings" error in the
307        case when an overflowing capture is in a branch that is subsequently
308        abandoned after a backtrack.
309    
310    13. In the pathological case when an offset vector of size 2 is used, pcretest
311        now prints out the matched string after a yield of 0 or 1.
312    
313    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
314        Only supported by the JIT compiler at the moment.
315    
316    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
317    
318    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
319        offset of the starting point of the matching process, provided the offsets
320        vector is large enough.
321    
322    17. The \A escape now records a lookbehind value of 1, though its execution
323        does not actually inspect the previous character. This is to ensure that,
324        in partial multi-segment matching, at least one character from the old
325        segment is retained when a new segment is processed. Otherwise, if there
326        are no lookbehinds in the pattern, \A might match incorrectly at the start
327        of a new segment.
328    
329    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
330    
331    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
332        gives some modest performance improvement in 8-bit mode.
333    
334    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
335        be expressed in certain programming languages using Universal Character
336        Names.
337    
338    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
339        which points out that "non characters" are not "characters that may not
340        appear in Unicode strings" but rather "characters that are reserved for
341        internal use and have only local meaning".
342    
343    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
344        there was a conditional group that depended on an assertion, if the
345        assertion was false, the callout that immediately followed the alternation
346        in the condition was skipped when pcre_exec() was used for matching.
347    
348    23. Allow an explicit callout to be inserted before an assertion that is the
349        condition for a conditional group, for compatibility with automatic
350        callouts, which always insert a callout at this point.
351    
352    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
353        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
354    
355    25. (*PRUNE) is now supported by the JIT compiler.
356    
357    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
358    
359    27. Fix the case where there are two or more SKIPs with arguments that may be
360        ignored.
361    
362    28. (*SKIP) is now supported by the JIT compiler.
363    
364    29. (*THEN) is now supported by the JIT compiler.
365    
366    30. Update RunTest with additional test selector options.
367    
368    31. The way PCRE handles backtracking verbs has been changed in two ways.
369    
370        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
371        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
372        backtracking. In some cases this makes it more Perl-compatible, but Perl's
373        rather obscure rules do not always do the same thing.
374    
375        (2) Previously, backtracking verbs were confined within assertions. This is
376        no longer the case for positive assertions, except for (*ACCEPT). Again,
377        this sometimes improves Perl compatibility, and sometimes does not.
378    
379    32. A number of tests that were in test 2 because Perl did things differently
380        have been moved to test 1, because either Perl or PCRE has changed, and
381        these tests are now compatible.
382    
383    32. Backtracking control verbs are now handled in the same way in JIT and
384        interpreter.
385    
386    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
387        contained a forward subroutine reference caused a compile error.
388    
389    34. Auto-detect and optimize limited repetitions in JIT.
390    
391    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
392        blocking (*UTF) etc.
393    
394    36. In the interpreter, maximizing pattern repetitions for characters and
395        character types now use tail recursion, which reduces stack usage.
396    
397    37. The value of the max lookbehind was not correctly preserved if a compiled
398        and saved regex was reloaded on a host of different endianness.
399    
400    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
401        of the compiled pattern block, expand the flags field from 16 to 32 bits
402        because it was almost full.
403    
404    39. Try madvise first before posix_madvise.
405    
406    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
407        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
408        original change locked out all matches of empty strings. This has been
409        changed so that one match of an empty string per line is recognized.
410        Subsequent searches on the same line (for colouring or for --only-matching,
411        for example) do not recognize empty strings.
412    
413    41. Applied a user patch to fix a number of spelling mistakes in comments.
414    
415    42. Data lines longer than 65536 caused pcretest to crash.
416    
417    43. Clarified the data type for length and startoffset arguments for pcre_exec
418        and pcre_dfa_exec in the function-specific man pages, where they were
419        explicitly stated to be in bytes, never having been updated. I also added
420        some clarification to the pcreapi man page.
421    
422    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
423        a segmentation fault.
424    
425    
426    Version 8.32 30-November-2012
427    -----------------------------
428    
429    1.  Improved JIT compiler optimizations for first character search and single
430        character iterators.
431    
432    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
433        Patch by Daniel Richard G.
434    
435    3.  Single character iterator optimizations in the JIT compiler.
436    
437    4.  Improved JIT compiler optimizations for character ranges.
438    
439    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
440        Reported by Giuseppe D'Angelo.
441    
442    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
443        of a line, was being set incorrectly in cases where .* appeared inside
444        atomic brackets at the start of a pattern, or where there was a subsequent
445        *PRUNE or *SKIP.
446    
447    7.  Improved instruction cache flush for POWER/PowerPC.
448        Patch by Daniel Richard G.
449    
450    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
451        grep:
452    
453        (a) There is now no limit to the number of patterns to be matched.
454    
455        (b) An error is given if a pattern is too long.
456    
457        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
458            are now supported.
459    
460        (d) --exclude-from and --include-from (multiple use) have been added.
461    
462        (e) Exclusions and inclusions now apply to all files and directories, not
463            just to those obtained from scanning a directory recursively.
464    
465        (f) Multiple uses of -f and --file-list are now supported.
466    
467        (g) In a Windows environment, the default for -d has been changed from
468            "read" (the GNU grep default) to "skip", because otherwise the presence
469            of a directory in the file list provokes an error.
470    
471        (h) The documentation has been revised and clarified in places.
472    
473    9.  Improve the matching speed of capturing brackets.
474    
475    10. Changed the meaning of \X so that it now matches a Unicode extended
476        grapheme cluster.
477    
478    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
479        out POSIX threads when JIT support is configured.
480    
481    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
482    
483    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
484        structure could go wrong in environments where size_t is not the same size
485        as int.
486    
487    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
488        set.
489    
490    15. The EBCDIC support had decayed; later updates to the code had included
491        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
492        general tidy up of EBCDIC-related issues, and the documentation was also
493        not quite right. There is now a test that can be run on ASCII systems to
494        check some of the EBCDIC-related things (but is it not a full test).
495    
496    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
497        in a small tidy to the code.
498    
499    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
500    
501    18. If the --only-matching (-o) option in pcregrep is specified multiple
502        times, each one causes appropriate output. For example, -o1 -o2 outputs the
503        substrings matched by the 1st and 2nd capturing parentheses. A separating
504        string can be specified by --om-separator (default empty).
505    
506    19. Improving the first n character searches.
507    
508    20. Turn case lists for horizontal and vertical white space into macros so that
509        they are defined only once.
510    
511    21. This set of changes together give more compatible Unicode case-folding
512        behaviour for characters that have more than one other case when UCP
513        support is available.
514    
515        (a) The Unicode property table now has offsets into a new table of sets of
516            three or more characters that are case-equivalent. The MultiStage2.py
517            script that generates these tables (the pcre_ucd.c file) now scans
518            CaseFolding.txt instead of UnicodeData.txt for character case
519            information.
520    
521        (b) The code for adding characters or ranges of characters to a character
522            class has been abstracted into a generalized function that also handles
523            case-independence. In UTF-mode with UCP support, this uses the new data
524            to handle characters with more than one other case.
525    
526        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
527            whose other case is greater than 256 are now correctly matched
528            caselessly. Previously, the high codepoint matched the low one, but not
529            vice versa.
530    
531        (d) The processing of \h, \H, \v, and \ in character classes now makes use
532            of the new class addition function, using character lists defined as
533            macros alongside the case definitions of 20 above.
534    
535        (e) Caseless back references now work with characters that have more than
536            one other case.
537    
538        (f) General caseless matching of characters with more than one other case
539            is supported.
540    
541    22. Unicode character properties were updated from Unicode 6.2.0
542    
543    23. Improved CMake support under Windows. Patch by Daniel Richard G.
544    
545    24. Add support for 32-bit character strings, and UTF-32
546    
547    25. Major JIT compiler update (code refactoring and bugfixing).
548        Experimental Sparc 32 support is added.
549    
550    26. Applied a modified version of Daniel Richard G's patch to create
551        pcre.h.generic and config.h.generic by "make" instead of in the
552        PrepareRelease script.
553    
554    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
555        pcre_compile.c when checking for a zero character.
556    
557    28. Introducing a native interface for JIT. Through this interface, the compiled
558        machine code can be directly executed. The purpose of this interface is to
559        provide fast pattern matching, so several sanity checks are not performed.
560        However, feature tests are still performed. The new interface provides
561        1.4x speedup compared to the old one.
562    
563    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
564        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
565        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
566    
567    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
568        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
569        the "old" RFC 2279). Instead, it ended up passing a negative length to
570        pcre_exec().
571    
572    31. Add support for GCC's visibility feature to hide internal functions.
573    
574    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
575        "unknown -C option" after outputting 0 or 1.
576    
577    33. There is now support for generating a code coverage report for the test
578        suite in environments where gcc is the compiler and lcov is installed. This
579        is mainly for the benefit of the developers.
580    
581    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
582        unaddressable using valgrind annotations, allowing valgrind to detect
583        invalid memory accesses. This is mainly for the benefit of the developers.
584    
585    25. (*UTF) can now be used to start a pattern in any of the three libraries.
586    
587    26. Give configure error if --enable-cpp but no C++ compiler found.
588    
589    
590    Version 8.31 06-July-2012
591    -------------------------
592    
593    1.  Fixing a wrong JIT test case and some compiler warnings.
594    
595    2.  Removed a bashism from the RunTest script.
596    
597    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
598        to unsigned type, result still unsigned" that was given by an MS compiler
599        on encountering the code "-sizeof(xxx)".
600    
601    4.  Partial matching support is added to the JIT compiler.
602    
603    5.  Fixed several bugs concerned with partial matching of items that consist
604        of more than one character:
605    
606        (a) /^(..)\1/ did not partially match "aba" because checking references was
607            done on an "all or nothing" basis. This also applied to repeated
608            references.
609    
610        (b) \R did not give a hard partial match if \r was found at the end of the
611            subject.
612    
613        (c) \X did not give a hard partial match after matching one or more
614            characters at the end of the subject.
615    
616        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
617            a partial match for the string "\r".
618    
619        (e) When newline was set to CRLF, the metacharacter "." did not recognize
620            a partial match for a CR character at the end of the subject string.
621    
622    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
623        running pcretest, the text "(JIT)" added to the output whenever JIT is
624        actually used to run the match.
625    
626    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
627        or /S+[+] with a digit between 1 and 7.
628    
629    8.  OP_NOT now supports any UTF character not just single-byte ones.
630    
631    9.  (*MARK) control verb is now supported by the JIT compiler.
632    
633    10. The command "./RunTest list" lists the available tests without actually
634        running any of them. (Because I keep forgetting what they all are.)
635    
636    11. Add PCRE_INFO_MAXLOOKBEHIND.
637    
638    12. Applied a (slightly modified) user-supplied patch that improves performance
639        when the heap is used for recursion (compiled with --disable-stack-for-
640        recursion). Instead of malloc and free for each heap frame each time a
641        logical recursion happens, frames are retained on a chain and re-used where
642        possible. This sometimes gives as much as 30% improvement.
643    
644    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
645        call.
646    
647    14. As documented, (*COMMIT) is now confined to within a positive assertion.
648    
649    15. It is now possible to link pcretest with libedit as an alternative to
650        libreadline.
651    
652    16. (*COMMIT) control verb is now supported by the JIT compiler.
653    
654    17. The Unicode data tables have been updated to Unicode 6.1.0.
655    
656    18. Added --file-list option to pcregrep.
657    
658    19. Added binary file support to pcregrep, including the -a, --binary-files,
659        -I, and --text options.
660    
661    20. The madvise function is renamed for posix_madvise for QNX compatibility
662        reasons. Fixed by Giuseppe D'Angelo.
663    
664    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
665    
666    22. Changed the option for creating symbolic links for 16-bit man pages from
667        -s to -sf so that re-installing does not cause issues.
668    
669    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
670    
671    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
672        matches in certain environments (the workspace was not being correctly
673        retained). Also added to pcre_dfa_exec() a simple plausibility check on
674        some of the workspace data at the beginning of a restart.
675    
676    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
677        was not doing so when it should - probably a typo introduced by SVN 528
678        (change 8.10/14).
679    
680    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
681        \w+ when the character tables indicated that \x{c4} was a word character.
682        There were several related cases, all because the tests for doing a table
683        lookup were testing for characters less than 127 instead of 255.
684    
685    27. If a pattern contains capturing parentheses that are not used in a match,
686        their slots in the ovector are set to -1. For those that are higher than
687        any matched groups, this happens at the end of processing. In the case when
688        there were back references that the ovector was too small to contain
689        (causing temporary malloc'd memory to be used during matching), and the
690        highest capturing number was not used, memory off the end of the ovector
691        was incorrectly being set to -1. (It was using the size of the temporary
692        memory instead of the true size.)
693    
694    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
695        ovector size, it uses memory at the end of the block that it has got.
696    
697    29. Check for an overlong MARK name and give an error at compile time. The
698        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
699    
700    30. JIT compiler update.
701    
702    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
703        Rill for the patch.
704    
705    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
706    
707    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
708    
709    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
710        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
711        was enabled.
712    
713    35. Improve JIT code generation for greedy plus quantifier.
714    
715    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
716        1 to "aa" instead of to an empty string. The bug affected repeated groups
717        that could potentially match an empty string.
718    
719    37. Optimizing single character iterators in JIT.
720    
721    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
722        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
723        codepoints that are too big for the mode are faulted, and in a UTF mode,
724        disallowed codepoints are also faulted.
725    
726    39. If PCRE was compiled with UTF support, in three places in the DFA
727        matcher there was code that should only have been obeyed in UTF mode, but
728        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
729        processing when bytes with values greater than 127 were present. In 16-bit
730        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
731        both cases the values are those that cannot be the first data item in a UTF
732        character. The three items that might have provoked this were recursions,
733        possessively repeated groups, and atomic groups.
734    
735    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
736        and pcregrep, because some OS require shared objects to be explicitly
737        passed to ld, causing the link step to fail if they are not.
738    
739    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
740        mode, patterns that started with \h* or \R* might be incorrectly matched.
741    
742    
743    Version 8.30 04-February-2012
744    -----------------------------
745    
746    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
747        name is defined in ctype.h.
748    
749    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
750        only in quite long subpatterns.
751    
752    3.  Removed the function pcre_info(), which has been obsolete and deprecated
753        since it was replaced by pcre_fullinfo() in February 2000.
754    
755    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
756        match a (*MARK), and the match failed at the start of the subject, a
757        reference to memory before the start of the subject could occur. This bug
758        was introduced by fix 17 of release 8.21.
759    
760    5.  A reference to an unset group with zero minimum repetition was giving
761        totally wrong answers (in non-JavaScript-compatibility mode). For example,
762        /(another)?(\1?)test/ matched against "hello world test". This bug was
763        introduced in release 8.13.
764    
765    6.  Add support for 16-bit character strings (a large amount of work involving
766        many changes and refactorings).
767    
768    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
769        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
770        from a file.
771    
772    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
773        rounding is not applied in this particular case).
774    
775    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
776        if they appear, or are escaped, in patterns.
777    
778    10. Get rid of a number of -Wunused-but-set-variable warnings.
779    
780    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
781        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
782        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
783        also returns the mark "x". This bug applied to capturing parentheses,
784        non-capturing parentheses, and atomic parentheses. It also applied to some
785        assertions.
786    
787    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
788        information out of configure.ac instead of relying on pcre.h.generic, which
789        is not stored in the repository.
790    
791    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
792        -lreadline.
793    
794    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
795    
796    15. Applied Graycode's patch to put the top-level frame on the stack rather
797        than the heap when not using the stack for recursion. This gives a
798        performance improvement in many cases when recursion is not deep.
799    
800    16. Experimental code added to "pcretest -C" to output the stack frame size.
801    
802    
803    Version 8.21 12-Dec-2011
804    ------------------------
805    
806    1.  Updating the JIT compiler.
807    
808    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
809        are added as well.
810    
811    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
812        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
813        calling _pcre_jit_exec. Some extra comments are added.
814    
815    4.  (*MARK) settings inside atomic groups that do not contain any capturing
816        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
817        was introduced by change 18 for 8.20.
818    
819    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
820        ECMA-262 standard.
821    
822    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
823        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
824        This bug was probably introduced by change 9 of 8.13.
825    
826    7.  While fixing 6 above, I noticed that a number of other items were being
827        incorrectly rejected as "not fixed length". This arose partly because newer
828        opcodes had not been added to the fixed-length checking code. I have (a)
829        corrected the bug and added tests for these items, and (b) arranged for an
830        error to occur if an unknown opcode is encountered while checking for fixed
831        length instead of just assuming "not fixed length". The items that were
832        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
833        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
834        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
835    
836    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
837        being incorrectly compiled and would have given unpredicatble results.
838    
839    9.  A possessively repeated subpattern with minimum repeat count greater than
840        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
841        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
842        the first (A) could occur when it should not.
843    
844    10. Add a cast and remove a redundant test from the code.
845    
846    11. JIT should use pcre_malloc/pcre_free for allocation.
847    
848    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
849        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
850        is anything other than /usr, -L is still shown).
851    
852    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
853    
854    14. Perl does not support \N without a following name in a [] class; PCRE now
855        also gives an error.
856    
857    15. If a forward reference was repeated with an upper limit of around 2000,
858        it caused the error "internal error: overran compiling workspace". The
859        maximum number of forward references (including repeats) was limited by the
860        internal workspace, and dependent on the LINK_SIZE. The code has been
861        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
862        the default depends on LINK_SIZE. There is a new upper limit (for safety)
863        of around 200,000 forward references. While doing this, I also speeded up
864        the filling in of repeated forward references.
865    
866    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
867        incorrectly expecting the subject to contain another "a" after the start.
868    
869    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
870        in the match, the SKIP should be ignored. This was not happening; instead
871        the SKIP was being treated as NOMATCH. For patterns such as
872        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
873        tested.
874    
875    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
876        now much more compatible with Perl, in particular in cases where the result
877        is a non-match for a non-anchored pattern. For example, if
878        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
879        "m", where previously it did not return a name. A side effect of this
880        change is that for partial matches, the last encountered mark name is
881        returned, as for non matches. A number of tests that were previously not
882        Perl-compatible have been moved into the Perl-compatible test files. The
883        refactoring has had the pleasing side effect of removing one argument from
884        the match() function, thus reducing its stack requirements.
885    
886    19. If the /S+ option was used in pcretest to study a pattern using JIT,
887        subsequent uses of /S (without +) incorrectly behaved like /S+.
888    
889    21. Retrieve executable code size support for the JIT compiler and fixing
890        some warnings.
891    
892    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
893        not work when the shorter character appeared right at the end of the
894        subject string.
895    
896    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
897        systems.
898    
899    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
900        output it when the /M option is used in pcretest.
901    
902    25. The CheckMan script was not being included in the distribution. Also, added
903        an explicit "perl" to run Perl scripts from the PrepareRelease script
904        because this is reportedly needed in Windows.
905    
906    26. If study data was being save in a file and studying had not found a set of
907        "starts with" bytes for the pattern, the data written to the file (though
908        never used) was taken from uninitialized memory and so caused valgrind to
909        complain.
910    
911    27. Updated RunTest.bat as provided by Sheri Pierce.
912    
913    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
914    
915    29. Computation of memory usage for the table of capturing group names was
916        giving an unnecessarily large value.
917    
918    
919    Version 8.20 21-Oct-2011
920    ------------------------
921    
922    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
923        a POSIX class. After further experiments with Perl, which convinced me that
924        Perl has bugs and confusions, a closing square bracket is no longer allowed
925        in a POSIX name. This bug also affected patterns with classes that started
926        with full stops.
927    
928    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
929        captured substring, but while checking the failing first alternative,
930        substring 1 is temporarily captured. If the output vector supplied to
931        pcre_exec() was not big enough for this capture, the yield of the function
932        was still zero ("insufficient space for captured substrings"). This cannot
933        be totally fixed without adding another stack variable, which seems a lot
934        of expense for a edge case. However, I have improved the situation in cases
935        such as /(a)(b)x|abc/ matched against "abc", where the return code
936        indicates that fewer than the maximum number of slots in the ovector have
937        been set.
938    
939    3.  Related to (2) above: when there are more back references in a pattern than
940        slots in the output vector, pcre_exec() uses temporary memory during
941        matching, and copies in the captures as far as possible afterwards. It was
942        using the entire output vector, but this conflicts with the specification
943        that only 2/3 is used for passing back captured substrings. Now it uses
944        only the first 2/3, for compatibility. This is, of course, another edge
945        case.
946    
947    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
948        main code base, and can be used by building with --enable-jit. When this is
949        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
950        runtime --no-jit option is given.
951    
952    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
953        ovector, the return from the function was zero, implying that there were
954        other matches that did not fit. The correct "exactly full" value is now
955        returned.
956    
957    6.  If a subpattern that was called recursively or as a subroutine contained
958        (*PRUNE) or any other control that caused it to give a non-standard return,
959        invalid errors such as "Error -26 (nested recursion at the same subject
960        position)" or even infinite loops could occur.
961    
962    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
963        computing the minimum length on reaching *ACCEPT, and so ended up with the
964        wrong value of 1 rather than 0. Further investigation indicates that
965        computing a minimum subject length in the presence of *ACCEPT is difficult
966        (think back references, subroutine calls), and so I have changed the code
967        so that no minimum is registered for a pattern that contains *ACCEPT.
968    
969    8.  If (*THEN) was present in the first (true) branch of a conditional group,
970        it was not handled as intended. [But see 16 below.]
971    
972    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
973        Sheri Pierce.
974    
975    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
976        the first byte in a match must be "a".
977    
978    11. Change 17 for 8.13 increased the recursion depth for patterns like
979        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
980        pattern contains any instances of (*THEN). If it does not, the old
981        optimizations are restored. It would be nice to do this on a per-group
982        basis, but at the moment that is not feasible.
983    
984    12. In some environments, the output of pcretest -C is CRLF terminated. This
985        broke RunTest's code that checks for the link size. A single white space
986        character after the value is now allowed for.
987    
988    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
989        For "fr", it uses the Windows-specific input and output files.
990    
991    14. If (*THEN) appeared in a group that was called recursively or as a
992        subroutine, it did not work as intended. [But see next item.]
993    
994    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
995        pattern fragments (but not containing any | characters). If A and B are
996        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
997        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
998        D. In other words, Perl considers parentheses that do not contain any |
999        characters to be part of a surrounding alternative, whereas PCRE was
1000        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1001        differently. PCRE now behaves in the same way as Perl, except in the case
1002        of subroutine/recursion calls such as (?1) which have in any case always
1003        been different (but PCRE had them first :-).
1004    
1005    16. Related to 15 above: Perl does not treat the | in a conditional group as
1006        creating alternatives. Such a group is treated in the same way as an
1007        ordinary group without any | characters when processing (*THEN). PCRE has
1008        been changed to match Perl's behaviour.
1009    
1010    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1011        RunGrepTest script failed.
1012    
1013    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1014        inevitable for groups that contain captures, but it can lead to a lot of
1015        stack use in large patterns. The old behaviour has been restored for atomic
1016        groups that do not contain any capturing parentheses.
1017    
1018    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1019        suppress the check for a minimum subject length at run time. (If it was
1020        given to pcre_exec() or pcre_dfa_exec() it did work.)
1021    
1022    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1023        fail to work when decoding hex characters in data strings in EBCDIC
1024        environments.
1025    
1026    21. It appears that in at least one Mac OS environment, the isxdigit() function
1027        is implemented as a macro that evaluates to its argument more than once,
1028        contravening the C 90 Standard (I haven't checked a later standard). There
1029        was an instance in pcretest which caused it to go wrong when processing
1030        \x{...} escapes in subject strings. The has been rewritten to avoid using
1031        things like p++ in the argument of isxdigit().
1032    
1033    
1034    Version 8.13 16-Aug-2011
1035    ------------------------
1036    
1037    1.  The Unicode data tables have been updated to Unicode 6.0.0.
1038    
1039    2.  Two minor typos in pcre_internal.h have been fixed.
1040    
1041    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1042        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1043        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1044    
1045    4.  There were a number of related bugs in the code for matching backrefences
1046        caselessly in UTF-8 mode when codes for the characters concerned were
1047        different numbers of bytes. For example, U+023A and U+2C65 are an upper
1048        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1049        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1050        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1051        2-byte code at the end of the subject (it thought there wasn't enough data
1052        left).
1053    
1054    5.  Comprehensive information about what went wrong is now returned by
1055        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1056        as the output vector has at least 2 elements. The offset of the start of
1057        the failing character and a reason code are placed in the vector.
1058    
1059    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1060        now returned is for the first byte of the failing character, instead of the
1061        last byte inspected. This is an incompatible change, but I hope it is small
1062        enough not to be a problem. It makes the returned offset consistent with
1063        pcre_exec() and pcre_dfa_exec().
1064    
1065    7.  pcretest now gives a text phrase as well as the error number when
1066        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1067        failure, the offset and reason code are output.
1068    
1069    8.  When \R was used with a maximizing quantifier it failed to skip backwards
1070        over a \r\n pair if the subsequent match failed. Instead, it just skipped
1071        back over a single character (\n). This seems wrong (because it treated the
1072        two characters as a single entity when going forwards), conflicts with the
1073        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1074        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1075        has been changed.
1076    
1077    9.  Some internal refactoring has changed the processing so that the handling
1078        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1079        time (the PCRE_DOTALL option was changed this way some time ago: version
1080        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1081        which was always a bit of a fudge. It also means that there is one less
1082        argument for the match() function, which reduces its stack requirements
1083        slightly. This change also fixes an incompatibility with Perl: the pattern
1084        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1085    
1086    10. More internal refactoring has drastically reduced the number of recursive
1087        calls to match() for possessively repeated groups such as (abc)++ when
1088        using pcre_exec().
1089    
1090    11. While implementing 10, a number of bugs in the handling of groups were
1091        discovered and fixed:
1092    
1093        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1094        (a|)*(?1) gave a compile-time internal error.
1095        ((a|)+)+  did not notice that the outer group could match an empty string.
1096        (^a|^)+   was not marked as anchored.
1097        (.*a|.*)+ was not marked as matching at start or after a newline.
1098    
1099    12. Yet more internal refactoring has removed another argument from the match()
1100        function. Special calls to this function are now indicated by setting a
1101        value in a variable in the "match data" data block.
1102    
1103    13. Be more explicit in pcre_study() instead of relying on "default" for
1104        opcodes that mean there is no starting character; this means that when new
1105        ones are added and accidentally left out of pcre_study(), testing should
1106        pick them up.
1107    
1108    14. The -s option of pcretest has been documented for ages as being an old
1109        synonym of -m (show memory usage). I have changed it to mean "force study
1110        for every regex", that is, assume /S for every regex. This is similar to -i
1111        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1112        using it. It makes it easier to run collections of tests with and without
1113        study enabled, and thereby test pcre_study() more easily. All the standard
1114        tests are now run with and without -s (but some patterns can be marked as
1115        "never study" - see 20 below).
1116    
1117    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1118        restoration of the capturing data to the outer values was not happening
1119        correctly.
1120    
1121    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1122        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1123        pattern had matched an empty string, and so incorrectly returned a no
1124        match.
1125    
1126    17. There was optimizing code for the last branch of non-capturing parentheses,
1127        and also for the obeyed branch of a conditional subexpression, which used
1128        tail recursion to cut down on stack usage. Unfortunately, now that there is
1129        the possibility of (*THEN) occurring in these branches, tail recursion is
1130        no longer possible because the return has to be checked for (*THEN). These
1131        two optimizations have therefore been removed. [But see 8.20/11 above.]
1132    
1133    18. If a pattern containing \R was studied, it was assumed that \R always
1134        matched two bytes, thus causing the minimum subject length to be
1135        incorrectly computed because \R can also match just one byte.
1136    
1137    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1138        was incorrectly computed.
1139    
1140    20. If /S is present twice on a test pattern in pcretest input, it now
1141        *disables* studying, thereby overriding the use of -s on the command line
1142        (see 14 above). This is necessary for one or two tests to keep the output
1143        identical in both cases.
1144    
1145    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1146        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1147    
1148    22. When an atomic group that contained a capturing parenthesis was
1149        successfully matched, but the branch in which it appeared failed, the
1150        capturing was not being forgotten if a higher numbered group was later
1151        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1152        group 1 to "a", when in fact it should be unset. This applied to multi-
1153        branched capturing and non-capturing groups, repeated or not, and also to
1154        positive assertions (capturing in negative assertions does not happen
1155        in PCRE) and also to nested atomic groups.
1156    
1157    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1158        subject after a captured substring, to make it easier to tell which of a
1159        number of identical substrings has been captured.
1160    
1161    24. The way atomic groups are processed by pcre_exec() has been changed so that
1162        if they are repeated, backtracking one repetition now resets captured
1163        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1164        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1165        "aaa". Previously, it would have been "a". As part of this code
1166        refactoring, the way recursive calls are handled has also been changed.
1167    
1168    25. If an assertion condition captured any substrings, they were not passed
1169        back unless some other capturing happened later. For example, if
1170        (?(?=(a))a) was matched against "a", no capturing was returned.
1171    
1172    26. When studying a pattern that contained subroutine calls or assertions,
1173        the code for finding the minimum length of a possible match was handling
1174        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1175        group 1 called group 2 while simultaneously a separate group 2 called group
1176        1). A stack overflow occurred in this case. I have fixed this by limiting
1177        the recursion depth to 10.
1178    
1179    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1180        Fortmann. This supports explicit test numbers on the command line, and has
1181        argument validation and error reporting.
1182    
1183    28. An instance of \X with an unlimited repeat could fail if at any point the
1184        first character it looked at was a mark character.
1185    
1186    29. Some minor code refactoring concerning Unicode properties and scripts
1187        should reduce the stack requirement of match() slightly.
1188    
1189    30. Added the '=' option to pcretest to check the setting of unused capturing
1190        slots at the end of the pattern, which are documented as being -1, but are
1191        not included in the return count.
1192    
1193    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1194        compiled something random. Now it gives a compile-time error (as does
1195        Perl).
1196    
1197    32. A *MARK encountered during the processing of a positive assertion is now
1198        recorded and passed back (compatible with Perl).
1199    
1200    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1201        had alternative anchored branches, the search for a second match in a line
1202        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1203        matched the line "0102" twice. The same bug affected patterns that started
1204        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1205        twice.
1206    
1207    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1208        does, and because of capturing effects, quantifying parenthesized
1209        assertions may at times be useful. Quantifiers are now allowed for
1210        parenthesized assertions.
1211    
1212    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1213    
1214    36. \g was being checked for fancy things in a character class, when it should
1215        just be a literal "g".
1216    
1217    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1218        appearance of a nested POSIX class supersedes an apparent external class.
1219        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1220        unescaped square brackets may also appear as part of class names. For
1221        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1222        more like Perl. (But see 8.20/1 above.)
1223    
1224    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1225        was because it thought it was \N{name}, which is not supported).
1226    
1227    39. Add minix to OS list not supporting the -S option in pcretest.
1228    
1229    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1230        cannot analyze patterns in sufficient detail to catch mutual recursions
1231        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1232        subgroup is called recursively as a subpattern for a second time at the
1233        same position in the subject string. In previous releases this might have
1234        been caught by the recursion limit, or it might have run out of stack.
1235    
1236    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1237        happen only once. PCRE was, however incorrectly giving a compile time error
1238        "recursive call could loop indefinitely" because it cannot analyze the
1239        pattern in sufficient detail. The compile time test no longer happens when
1240        PCRE is compiling a conditional subpattern, but actual runaway loops are
1241        now caught at runtime (see 40 above).
1242    
1243    42. It seems that Perl allows any characters other than a closing parenthesis
1244        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1245        has been changed to be the same.
1246    
1247    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1248        as not to get warnings when autogen.sh is called. Also changed
1249        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1250    
1251    44. To help people who use pcregrep to scan files containing exceedingly long
1252        lines, the following changes have been made:
1253    
1254        (a) The default value of the buffer size parameter has been increased from
1255            8K to 20K. (The actual buffer used is three times this size.)
1256    
1257        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1258            PCRE is built.
1259    
1260        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1261            to be set at run time.
1262    
1263        (d) Numerical values in pcregrep options can be followed by K or M, for
1264            example --buffer-size=50K.
1265    
1266        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1267            given and the return code is set to 2.
1268    
1269    45. Add a pointer to the latest mark to the callout data block.
1270    
1271    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1272        partial match of an empty string instead of no match. This was specific to
1273        the use of ".".
1274    
1275    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1276        complete match instead of a partial match. This bug was dependent on both
1277        the PCRE_UTF8 and PCRE_DOTALL options being set.
1278    
1279    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1280        starting byte set, because \b was not being ignored.
1281    
1282    
1283    Version 8.12 15-Jan-2011
1284    ------------------------
1285    
1286    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1287        checks for such things as part of the documentation building process.
1288    
1289    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1290        --match-limit and --recursion-limit options (added for 8.11). In
1291        particular, this made one of the standard tests fail. (The integer value
1292        went into the wrong half of a long int.)
1293    
1294    3.  If the --colour option was given to pcregrep with -v (invert match), it
1295        did strange things, either producing crazy output, or crashing. It should,
1296        of course, ignore a request for colour when reporting lines that do not
1297        match.
1298    
1299    4.  Another pcregrep bug caused similar problems if --colour was specified with
1300        -M (multiline) and the pattern match finished with a line ending.
1301    
1302    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1303        matched in multiline mode, the following line was shown as part of the
1304        match. This seems wrong, so I have changed it.
1305    
1306    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1307        the check for further matches in the same line (so they could be coloured)
1308        to overrun the end of the current line. If another match was found, it was
1309        incorrectly shown (and then shown again when found in the next line).
1310    
1311    7.  If pcregrep was compiled under Windows, there was a reference to the
1312        function pcregrep_exit() before it was defined. I am assuming this was
1313        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1314        reported by a user. I've moved the definition above the reference.
1315    
1316    
1317    Version 8.11 10-Dec-2010
1318    ------------------------
1319    
1320    1.  (*THEN) was not working properly if there were untried alternatives prior
1321        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1322        backtracked to try for "b" instead of moving to the next alternative branch
1323        at the same level (in this case, to look for "c"). The Perl documentation
1324        is clear that when (*THEN) is backtracked onto, it goes to the "next
1325        alternative in the innermost enclosing group".
1326    
1327    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1328        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1329        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1330        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1331        (*THEN).
1332    
1333    3.  If \s appeared in a character class, it removed the VT character from
1334        the class, even if it had been included by some previous item, for example
1335        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1336        of \s, but is part of the POSIX "space" class.)
1337    
1338    4.  A partial match never returns an empty string (because you can always
1339        match an empty string at the end of the subject); however the checking for
1340        an empty string was starting at the "start of match" point. This has been
1341        changed to the "earliest inspected character" point, because the returned
1342        data for a partial match starts at this character. This means that, for
1343        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1344        (previously it gave "no match").
1345    
1346    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1347        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1348        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1349        has an implication that the given string is incomplete (because a partial
1350        match is preferred over a full match). For this reason, these items now
1351        give a partial match in this situation. [Aside: previously, the one case
1352        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1353        match rather than a full match, which was wrong by the old rules, but is
1354        now correct.]
1355    
1356    6.  There was a bug in the handling of #-introduced comments, recognized when
1357        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1358        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1359        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1360        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1361        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1362        places in pcre_compile().
1363    
1364    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1365        comments when looking ahead for named forward references to subpatterns,
1366        the only newline sequence it recognized was NL. It now handles newlines
1367        according to the set newline convention.
1368    
1369    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1370        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1371        cater for a lack of strerror(). These oversights have been fixed.
1372    
1373    9.  Added --match-limit and --recursion-limit to pcregrep.
1374    
1375    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1376    
1377    11. When the -o option was used, pcregrep was setting a return code of 1, even
1378        when matches were found, and --line-buffered was not being honoured.
1379    
1380    12. Added an optional parentheses number to the -o and --only-matching options
1381        of pcregrep.
1382    
1383    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1384        can match an empty string. The code to do it in pcretest and pcredemo
1385        needed fixing:
1386    
1387        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1388            only one byte after an empty string match just before CRLF (this case
1389            just got forgotten; "any" and "anycrlf" were OK).
1390    
1391        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1392            mode when an empty string match preceded an ASCII character followed by
1393            a non-ASCII character. (The code for advancing by one character rather
1394            than one byte was nonsense.)
1395    
1396        (c) The pcredemo.c sample program did not have any code at all to handle
1397            the cases when CRLF is a valid newline sequence.
1398    
1399    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1400        as a starting offset was within the subject string. There is now a new
1401        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1402        negative or greater than the length of the string. In order to test this,
1403        pcretest is extended to allow the setting of negative starting offsets.
1404    
1405    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1406        starting offset points to the beginning of a UTF-8 character was
1407        unnecessarily clumsy. I tidied it up.
1408    
1409    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1410        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1411    
1412    17. Nobody had reported that the --include_dir option, which was added in
1413        release 7.7 should have been called --include-dir (hyphen, not underscore)
1414        for compatibility with GNU grep. I have changed it to --include-dir, but
1415        left --include_dir as an undocumented synonym, and the same for
1416        --exclude-dir, though that is not available in GNU grep, at least as of
1417        release 2.5.4.
1418    
1419    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1420        characters from a string of bytes) have been redefined so as not to use
1421        loops, in order to improve performance in some environments. At the same
1422        time, I abstracted some of the common code into auxiliary macros to save
1423        repetition (this should not affect the compiled code).
1424    
1425    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1426        compile-time error is now given if \c is not followed by an ASCII
1427        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1428        different, and any byte value is allowed.)
1429    
1430    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1431        START_OPTIMIZE option, which is now allowed at compile time - but just
1432        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1433        to pcregrep and other applications that have no direct access to PCRE
1434        options. The new /Y option in pcretest sets this option when calling
1435        pcre_compile().
1436    
1437    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1438        back references. Groups containing recursive back references were forced to
1439        be atomic by that change, but in the case of named groups, the amount of
1440        memory required was incorrectly computed, leading to "Failed: internal
1441        error: code overflow". This has been fixed.
1442    
1443    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1444        pcretest.c, to avoid build problems in some Borland environments.
1445    
1446    
1447    Version 8.10 25-Jun-2010
1448    ------------------------
1449    
1450    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1451        THEN.
1452    
1453    2.  (*ACCEPT) was not working when inside an atomic group.
1454    
1455    3.  Inside a character class, \B is treated as a literal by default, but
1456        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1457        causes the error). The code is unchanged, but I tidied the documentation.
1458    
1459    4.  Inside a character class, PCRE always treated \R and \X as literals,
1460        whereas Perl faults them if its -w option is set. I have changed PCRE so
1461        that it faults them when PCRE_EXTRA is set.
1462    
1463    5.  Added support for \N, which always matches any character other than
1464        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1465    
1466    6.  When compiling pcregrep with newer versions of gcc which may have
1467        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1468        declared with attribute warn_unused_result" were given. Just casting the
1469        result to (void) does not stop the warnings; a more elaborate fudge is
1470        needed. I've used a macro to implement this.
1471    
1472    7.  Minor change to pcretest.c to avoid a compiler warning.
1473    
1474    8.  Added four artifical Unicode properties to help with an option to make
1475        \s etc use properties (see next item). The new properties are: Xan
1476        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1477    
1478    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1479        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1480        this option. Modified pcretest to add /W to test this facility. Added
1481        REG_UCP to make it available via the POSIX interface.
1482    
1483    10. Added --line-buffered to pcregrep.
1484    
1485    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1486        studied, and the match started with a letter with a code point greater than
1487        127 whose first byte was different to the first byte of the other case of
1488        the letter, the other case of this starting letter was not recognized
1489        (#976).
1490    
1491    12. If a pattern that was studied started with a repeated Unicode property
1492        test, for example, \p{Nd}+, there was the theoretical possibility of
1493        setting up an incorrect bitmap of starting bytes, but fortunately it could
1494        not have actually happened in practice until change 8 above was made (it
1495        added property types that matched character-matching opcodes).
1496    
1497    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1498        possible starting bytes for non-anchored patterns.
1499    
1500    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1501        \R, and also a number of cases that involve Unicode properties, both
1502        explicit and implicit when PCRE_UCP is set.
1503    
1504    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1505        input, it could crash or give wrong results if characters with values
1506        greater than 0xc0 were present in the subject string. (Detail: it assumed
1507        UTF-8 input when processing these items.)
1508    
1509    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1510        size_t is 64-bit (#991).
1511    
1512    17. Added a check for running out of memory when PCRE is compiled with
1513        --disable-stack-for-recursion (#990).
1514    
1515    18. If the last data line in a file for pcretest does not have a newline on
1516        the end, a newline was missing in the output.
1517    
1518    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1519        less than 128) in its various bitmaps. However, there is a facility for
1520        generating tables according to the current locale when PCRE is compiled. It
1521        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1522        characters, are recognized by isspace() and therefore were getting set in
1523        these tables, and indeed these tables seem to approximate to ISO 8859. This
1524        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1525        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1526        which of course cannot start UTF-8 characters. I have changed the code so
1527        that only real ASCII characters (less than 128) and the correct starting
1528        bytes for UTF-8 encodings are set for characters greater than 127 when in
1529        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1530        altogether.)
1531    
1532    20. Added the /T option to pcretest so as to be able to run tests with non-
1533        standard character tables, thus making it possible to include the tests
1534        used for 19 above in the standard set of tests.
1535    
1536    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1537        reference to a subpattern the other side of a comment that contains an
1538        opening parenthesis caused either an internal compiling error, or a
1539        reference to the wrong subpattern.
1540    
1541    
1542    Version 8.02 19-Mar-2010
1543  ------------------------  ------------------------
1544    
1545  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
1546    
1547  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1548      configured.      configured.
1549    
1550  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1551      original author of that file, following a query about its status.      original author of that file, following a query about its status.
1552    
1553  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1554      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1555    
1556  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1557      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
1558      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
1559      referenced subpattern not found".      referenced subpattern not found".
1560    
1561  6.  Both MS Visual Studio and Symbian OS have problems with initializing  6.  Both MS Visual Studio and Symbian OS have problems with initializing
1562      variables to point to external functions. For these systems, therefore,      variables to point to external functions. For these systems, therefore,
1563      pcre_malloc etc. are now initialized to local functions that call the      pcre_malloc etc. are now initialized to local functions that call the
1564      relevant global functions.      relevant global functions.
1565    
1566  7.  There were two entries missing in the vectors called coptable and poptable  7.  There were two entries missing in the vectors called coptable and poptable
1567      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1568      I've fixed the data, and added a kludgy way of testing at compile time that      I've fixed the data, and added a kludgy way of testing at compile time that
1569      the lengths are correct (equal to the number of opcodes).      the lengths are correct (equal to the number of opcodes).
1570    
1571  8.  Following on from 7, I added a similar kludge to check the length of the  8.  Following on from 7, I added a similar kludge to check the length of the
1572      eint vector in pcreposix.c.      eint vector in pcreposix.c.
1573    
1574  9.  Error texts for pcre_compile() are held as one long string to avoid too  9.  Error texts for pcre_compile() are held as one long string to avoid too
1575      much relocation at load time. To find a text, the string is searched,      much relocation at load time. To find a text, the string is searched,
1576      counting zeros. There was no check for running off the end of the string,      counting zeros. There was no check for running off the end of the string,
1577      which could happen if a new error number was added without updating the      which could happen if a new error number was added without updating the
1578      string.      string.
1579    
1580  10. \K gave a compile-time error if it appeared in a lookbehind assersion.  10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1581    
1582  11. \K was not working if it appeared in an atomic group or in a group that  11. \K was not working if it appeared in an atomic group or in a group that
1583      was called as a "subroutine", or in an assertion. Perl 5.11 documents that      was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1584      \K is "not well defined" if used in an assertion. PCRE now accepts it if      \K is "not well defined" if used in an assertion. PCRE now accepts it if
1585      the assertion is positive, but not if it is negative.      the assertion is positive, but not if it is negative.
1586    
1587  12. Change 11 fortuitously reduced the size of the stack frame used in the  12. Change 11 fortuitously reduced the size of the stack frame used in the
1588      "match()" function of pcre_exec.c by one pointer. Forthcoming      "match()" function of pcre_exec.c by one pointer. Forthcoming
1589      implementation of support for (*MARK) will need an extra pointer on the      implementation of support for (*MARK) will need an extra pointer on the
1590      stack; I have reserved it now, so that the stack frame size does not      stack; I have reserved it now, so that the stack frame size does not
1591      decrease.      decrease.
1592    
1593  13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other  13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1594      item in branch that calls a recursion is a subroutine call - as in the      item in branch that calls a recursion is a subroutine call - as in the
1595      second branch in the above example - was incorrectly given the compile-      second branch in the above example - was incorrectly given the compile-
1596      time error "recursive call could loop indefinitely" because pcre_compile()      time error "recursive call could loop indefinitely" because pcre_compile()
1597      was not correctly checking the subroutine for matching a non-empty string.      was not correctly checking the subroutine for matching a non-empty string.
1598    
1599  14. The checks for overrunning compiling workspace could trigger after an  14. The checks for overrunning compiling workspace could trigger after an
1600      overrun had occurred. This is a "should never occur" error, but it can be      overrun had occurred. This is a "should never occur" error, but it can be
1601      triggered by pathological patterns such as hundreds of nested parentheses.      triggered by pathological patterns such as hundreds of nested parentheses.
1602      The checks now trigger 100 bytes before the end of the workspace.      The checks now trigger 100 bytes before the end of the workspace.
1603    
1604    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1605    
1606    
1607  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
# Line 390  Version 7.9 11-Apr-09 Line 1930  Version 7.9 11-Apr-09
1930  7.  A pattern that could match an empty string could cause pcregrep to loop; it  7.  A pattern that could match an empty string could cause pcregrep to loop; it
1931      doesn't make sense to accept an empty string match in pcregrep, so I have      doesn't make sense to accept an empty string match in pcregrep, so I have
1932      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1933      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1934        8.33.]
1935    
1936  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1937      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 633  Version 7.7 07-May-08 Line 2174  Version 7.7 07-May-08
2174      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2175      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2176      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2177      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2178      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2179      was subsequently set up correctly.)      was subsequently set up correctly.)
2180    

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