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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    
45    Version 8.34 15-December-2013
46    -----------------------------
47    
48    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
49        executable memory. Patch inspired by Carsten Klein.
50    
51    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
52        this macro is never tested and has no effect, because the work to support
53        coverage involves only compiling and linking options and special targets in
54        the Makefile. The comment in config.h implied that defining the macro would
55        enable coverage support, which is totally false. There was also support for
56        setting this macro in the CMake files (my fault, I just copied it from
57        configure). SUPPORT_GCOV has now been removed.
58    
59    3.  Make a small performance improvement in strlen16() and strlen32() in
60        pcretest.
61    
62    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
63        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
64        these cases). There was also one in pcretest.c.
65    
66    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
67    
68    6.  In UTF mode, the code for checking whether a group could match an empty
69        string (which is used for indefinitely repeated groups to allow for
70        breaking an infinite loop) was broken when the group contained a repeated
71        negated single-character class with a character that occupied more than one
72        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
73        UTF-8 mode). The effect was undefined: the group might or might not be
74        deemed as matching an empty string, or the program might have crashed.
75    
76    7.  The code for checking whether a group could match an empty string was not
77        recognizing that \h, \H, \v, \V, and \R must match a character.
78    
79    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
80        an empty string. If it can, pcretest shows this in its information output.
81    
82    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
83        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
84        matched by pcre_exec() without using JIT:
85    
86        (a) If the rest of the pattern did not match after a maximal run of
87            grapheme clusters, the code for backing up to try with fewer of them
88            did not always back up over a full grapheme when characters that do not
89            have the modifier quality were involved, e.g. Hangul syllables.
90    
91        (b) If the match point in a subject started with modifier character, and
92            there was no match, the code could incorrectly back up beyond the match
93            point, and potentially beyond the first character in the subject,
94            leading to a segfault or an incorrect match result.
95    
96    10. A conditional group with an assertion condition could lead to PCRE
97        recording an incorrect first data item for a match if no other first data
98        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
99        first data item, and therefore matched "ca" after "c" instead of at the
100        start.
101    
102    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
103        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
104    
105    12. The source of pcregrep now includes z/OS-specific code so that it can be
106        compiled for z/OS as part of the special z/OS distribution.
107    
108    13. Added the -T and -TM options to pcretest.
109    
110    14. The code in pcre_compile.c for creating the table of named capturing groups
111        has been refactored. Instead of creating the table dynamically during the
112        actual compiling pass, the information is remembered during the pre-compile
113        pass (on the stack unless there are more than 20 named groups, in which
114        case malloc() is used) and the whole table is created before the actual
115        compile happens. This has simplified the code (it is now nearly 150 lines
116        shorter) and prepared the way for better handling of references to groups
117        with duplicate names.
118    
119    15. A back reference to a named subpattern when there is more than one of the
120        same name now checks them in the order in which they appear in the pattern.
121        The first one that is set is used for the reference. Previously only the
122        first one was inspected. This change makes PCRE more compatible with Perl.
123    
124    16. Unicode character properties were updated from Unicode 6.3.0.
125    
126    17. The compile-time code for auto-possessification has been refactored, based
127        on a patch by Zoltan Herczeg. It now happens after instead of during
128        compilation. The code is cleaner, and more cases are handled. The option
129        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
130        options in pcretest are provided to set it. It can also be set by
131        (*NO_AUTO_POSSESS) at the start of a pattern.
132    
133    18. The character VT has been added to the default ("C" locale) set of
134        characters that match \s and are generally treated as white space,
135        following this same change in Perl 5.18. There is now no difference between
136        "Perl space" and "POSIX space". Whether VT is treated as white space in
137        other locales depends on the locale.
138    
139    19. The code for checking named groups as conditions, either for being set or
140        for being recursed, has been refactored (this is related to 14 and 15
141        above). Processing unduplicated named groups should now be as fast at
142        numerical groups, and processing duplicated groups should be faster than
143        before.
144    
145    20. Two patches to the CMake build system, by Alexander Barkov:
146    
147          (1) Replace the "source" command by "." in CMakeLists.txt because
148              "source" is a bash-ism.
149    
150          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
151              without these the CMake build does not work on Solaris.
152    
153    21. Perl has changed its handling of \8 and \9. If there is no previously
154        encountered capturing group of those numbers, they are treated as the
155        literal characters 8 and 9 instead of a binary zero followed by the
156        literals. PCRE now does the same.
157    
158    22. Following Perl, added \o{} to specify codepoints in octal, making it
159        possible to specify values greater than 0777 and also making them
160        unambiguous.
161    
162    23. Perl now gives an error for missing closing braces after \x{... instead of
163        treating the string as literal. PCRE now does the same.
164    
165    24. RunTest used to grumble if an inappropriate test was selected explicitly,
166        but just skip it when running all tests. This make it awkward to run ranges
167        of tests when one of them was inappropriate. Now it just skips any
168        inappropriate tests, as it always did when running all tests.
169    
170    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
171        character types such as \d or \w, too many callouts were inserted, and the
172        data that they returned was rubbish.
173    
174    26. In UCP mode, \s was not matching two of the characters that Perl matches,
175        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
176        were matched by \h. The code has now been refactored so that the lists of
177        the horizontal and vertical whitespace characters used for \h and \v (which
178        are defined only in one place) are now also used for \s.
179    
180    27. Add JIT support for the 64 bit TileGX architecture.
181        Patch by Jiong Wang (Tilera Corporation).
182    
183    28. Possessive quantifiers for classes (both explicit and automatically
184        generated) now use special opcodes instead of wrapping in ONCE brackets.
185    
186    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
187        (because it's meaningless), this was not happening when PCRE_CASELESS was
188        set. Not wrong, but inefficient.
189    
190    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
191        properties for \w, \d, etc) is present in a test regex. Otherwise if the
192        test contains no characters greater than 255, Perl doesn't realise it
193        should be using Unicode semantics.
194    
195    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
196        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
197        does in Unicode mode.
198    
199    32. Added the "forbid" facility to pcretest so that putting tests into the
200        wrong test files can sometimes be quickly detected.
201    
202    33. There is now a limit (default 250) on the depth of nesting of parentheses.
203        This limit is imposed to control the amount of system stack used at compile
204        time. It can be changed at build time by --with-parens-nest-limit=xxx or
205        the equivalent in CMake.
206    
207    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
208        errors. Perl warns for these when in warning mode, but PCRE has no facility
209        for giving warnings.
210    
211    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
212        However, this was not working for (?!) because it is optimized to (*FAIL),
213        for which PCRE does not allow quantifiers. The optimization is now disabled
214        when a quantifier follows (?!). I can't see any use for this, but it makes
215        things uniform.
216    
217    36. Perl no longer allows group names to start with digits, so I have made this
218        change also in PCRE. It simplifies the code a bit.
219    
220    37. In extended mode, Perl ignores spaces before a + that indicates a
221        possessive quantifier. PCRE allowed a space before the quantifier, but not
222        before the possessive +. It now does.
223    
224    38. The use of \K (reset reported match start) within a repeated possessive
225        group such as (a\Kb)*+ was not working.
226    
227    40. Document that the same character tables must be used at compile time and
228        run time, and that the facility to pass tables to pcre_exec() and
229        pcre_dfa_exec() is for use only with saved/restored patterns.
230    
231    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
232        features for Builds with MSVC:
233    
234        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
235           builds). The .rc files can be used to set FileDescription and many other
236           attributes.
237    
238        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
239           This allows higher-level build scripts which want .pdb files to avoid
240           hard-coding the exact files needed."
241    
242    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
243        mean "start of word" and "end of word", respectively, as a transition aid.
244    
245    43. A minimizing repeat of a class containing codepoints greater than 255 in
246        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
247        compiled to use the heap for recursion.
248    
249    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
250        is configured.
251    
252    
253    Version 8.33 28-May-2013
254    ------------------------
255    
256    1.  Added 'U' to some constants that are compared to unsigned integers, to
257        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
258        variables that are added to signed variables, to ensure the result is
259        signed and can be negated.
260    
261    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
262        CMake config files.
263    
264    3.  Revise the creation of config.h.generic so that all boolean macros are
265        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
266        overriding via -D on the command line possible.
267    
268    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
269        to unsigned int is reported to make a quite noticeable speed difference in
270        a specific Windows environment. Testing on Linux did also appear to show
271        some benefit (and it is clearly not harmful). Also fixed the definition of
272        Xop which should be unsigned.
273    
274    5.  Related to (4), changing the definition of the intermediate variable cc
275        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
276        improvements.
277    
278    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
279        unnecessary spaces.
280    
281    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
282        and later.
283    
284    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
285    
286    9.  Optimizing fast_forward_start_bits in JIT.
287    
288    10. Adding support for callouts in JIT, and fixing some issues revealed
289        during this work. Namely:
290    
291        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
292    
293        (b) Minimum length was not checked before the matching is started.
294    
295    11. The value of capture_last that is passed to callouts was incorrect in some
296        cases when there was a capture on one path that was subsequently abandoned
297        after a backtrack. Also, the capture_last value is now reset after a
298        recursion, since all captures are also reset in this case.
299    
300    12. The interpreter no longer returns the "too many substrings" error in the
301        case when an overflowing capture is in a branch that is subsequently
302        abandoned after a backtrack.
303    
304    13. In the pathological case when an offset vector of size 2 is used, pcretest
305        now prints out the matched string after a yield of 0 or 1.
306    
307    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
308        Only supported by the JIT compiler at the moment.
309    
310    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
311    
312    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
313        offset of the starting point of the matching process, provided the offsets
314        vector is large enough.
315    
316    17. The \A escape now records a lookbehind value of 1, though its execution
317        does not actually inspect the previous character. This is to ensure that,
318        in partial multi-segment matching, at least one character from the old
319        segment is retained when a new segment is processed. Otherwise, if there
320        are no lookbehinds in the pattern, \A might match incorrectly at the start
321        of a new segment.
322    
323    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
324    
325    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
326        gives some modest performance improvement in 8-bit mode.
327    
328    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
329        be expressed in certain programming languages using Universal Character
330        Names.
331    
332    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
333        which points out that "non characters" are not "characters that may not
334        appear in Unicode strings" but rather "characters that are reserved for
335        internal use and have only local meaning".
336    
337    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
338        there was a conditional group that depended on an assertion, if the
339        assertion was false, the callout that immediately followed the alternation
340        in the condition was skipped when pcre_exec() was used for matching.
341    
342    23. Allow an explicit callout to be inserted before an assertion that is the
343        condition for a conditional group, for compatibility with automatic
344        callouts, which always insert a callout at this point.
345    
346    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
347        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
348    
349    25. (*PRUNE) is now supported by the JIT compiler.
350    
351    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
352    
353    27. Fix the case where there are two or more SKIPs with arguments that may be
354        ignored.
355    
356    28. (*SKIP) is now supported by the JIT compiler.
357    
358    29. (*THEN) is now supported by the JIT compiler.
359    
360    30. Update RunTest with additional test selector options.
361    
362    31. The way PCRE handles backtracking verbs has been changed in two ways.
363    
364        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
365        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
366        backtracking. In some cases this makes it more Perl-compatible, but Perl's
367        rather obscure rules do not always do the same thing.
368    
369        (2) Previously, backtracking verbs were confined within assertions. This is
370        no longer the case for positive assertions, except for (*ACCEPT). Again,
371        this sometimes improves Perl compatibility, and sometimes does not.
372    
373    32. A number of tests that were in test 2 because Perl did things differently
374        have been moved to test 1, because either Perl or PCRE has changed, and
375        these tests are now compatible.
376    
377    32. Backtracking control verbs are now handled in the same way in JIT and
378        interpreter.
379    
380    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
381        contained a forward subroutine reference caused a compile error.
382    
383    34. Auto-detect and optimize limited repetitions in JIT.
384    
385    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
386        blocking (*UTF) etc.
387    
388    36. In the interpreter, maximizing pattern repetitions for characters and
389        character types now use tail recursion, which reduces stack usage.
390    
391    37. The value of the max lookbehind was not correctly preserved if a compiled
392        and saved regex was reloaded on a host of different endianness.
393    
394    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
395        of the compiled pattern block, expand the flags field from 16 to 32 bits
396        because it was almost full.
397    
398    39. Try madvise first before posix_madvise.
399    
400    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
401        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
402        original change locked out all matches of empty strings. This has been
403        changed so that one match of an empty string per line is recognized.
404        Subsequent searches on the same line (for colouring or for --only-matching,
405        for example) do not recognize empty strings.
406    
407    41. Applied a user patch to fix a number of spelling mistakes in comments.
408    
409    42. Data lines longer than 65536 caused pcretest to crash.
410    
411    43. Clarified the data type for length and startoffset arguments for pcre_exec
412        and pcre_dfa_exec in the function-specific man pages, where they were
413        explicitly stated to be in bytes, never having been updated. I also added
414        some clarification to the pcreapi man page.
415    
416    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
417        a segmentation fault.
418    
419    
420    Version 8.32 30-November-2012
421    -----------------------------
422    
423    1.  Improved JIT compiler optimizations for first character search and single
424        character iterators.
425    
426    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
427        Patch by Daniel Richard G.
428    
429    3.  Single character iterator optimizations in the JIT compiler.
430    
431    4.  Improved JIT compiler optimizations for character ranges.
432    
433    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
434        Reported by Giuseppe D'Angelo.
435    
436    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
437        of a line, was being set incorrectly in cases where .* appeared inside
438        atomic brackets at the start of a pattern, or where there was a subsequent
439        *PRUNE or *SKIP.
440    
441    7.  Improved instruction cache flush for POWER/PowerPC.
442        Patch by Daniel Richard G.
443    
444    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
445        grep:
446    
447        (a) There is now no limit to the number of patterns to be matched.
448    
449        (b) An error is given if a pattern is too long.
450    
451        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
452            are now supported.
453    
454        (d) --exclude-from and --include-from (multiple use) have been added.
455    
456        (e) Exclusions and inclusions now apply to all files and directories, not
457            just to those obtained from scanning a directory recursively.
458    
459        (f) Multiple uses of -f and --file-list are now supported.
460    
461        (g) In a Windows environment, the default for -d has been changed from
462            "read" (the GNU grep default) to "skip", because otherwise the presence
463            of a directory in the file list provokes an error.
464    
465        (h) The documentation has been revised and clarified in places.
466    
467    9.  Improve the matching speed of capturing brackets.
468    
469    10. Changed the meaning of \X so that it now matches a Unicode extended
470        grapheme cluster.
471    
472    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
473        out POSIX threads when JIT support is configured.
474    
475    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
476    
477    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
478        structure could go wrong in environments where size_t is not the same size
479        as int.
480    
481    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
482        set.
483    
484    15. The EBCDIC support had decayed; later updates to the code had included
485        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
486        general tidy up of EBCDIC-related issues, and the documentation was also
487        not quite right. There is now a test that can be run on ASCII systems to
488        check some of the EBCDIC-related things (but is it not a full test).
489    
490    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
491        in a small tidy to the code.
492    
493    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
494    
495    18. If the --only-matching (-o) option in pcregrep is specified multiple
496        times, each one causes appropriate output. For example, -o1 -o2 outputs the
497        substrings matched by the 1st and 2nd capturing parentheses. A separating
498        string can be specified by --om-separator (default empty).
499    
500    19. Improving the first n character searches.
501    
502    20. Turn case lists for horizontal and vertical white space into macros so that
503        they are defined only once.
504    
505    21. This set of changes together give more compatible Unicode case-folding
506        behaviour for characters that have more than one other case when UCP
507        support is available.
508    
509        (a) The Unicode property table now has offsets into a new table of sets of
510            three or more characters that are case-equivalent. The MultiStage2.py
511            script that generates these tables (the pcre_ucd.c file) now scans
512            CaseFolding.txt instead of UnicodeData.txt for character case
513            information.
514    
515        (b) The code for adding characters or ranges of characters to a character
516            class has been abstracted into a generalized function that also handles
517            case-independence. In UTF-mode with UCP support, this uses the new data
518            to handle characters with more than one other case.
519    
520        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
521            whose other case is greater than 256 are now correctly matched
522            caselessly. Previously, the high codepoint matched the low one, but not
523            vice versa.
524    
525        (d) The processing of \h, \H, \v, and \ in character classes now makes use
526            of the new class addition function, using character lists defined as
527            macros alongside the case definitions of 20 above.
528    
529        (e) Caseless back references now work with characters that have more than
530            one other case.
531    
532        (f) General caseless matching of characters with more than one other case
533            is supported.
534    
535    22. Unicode character properties were updated from Unicode 6.2.0
536    
537    23. Improved CMake support under Windows. Patch by Daniel Richard G.
538    
539    24. Add support for 32-bit character strings, and UTF-32
540    
541    25. Major JIT compiler update (code refactoring and bugfixing).
542        Experimental Sparc 32 support is added.
543    
544    26. Applied a modified version of Daniel Richard G's patch to create
545        pcre.h.generic and config.h.generic by "make" instead of in the
546        PrepareRelease script.
547    
548    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
549        pcre_compile.c when checking for a zero character.
550    
551    28. Introducing a native interface for JIT. Through this interface, the compiled
552        machine code can be directly executed. The purpose of this interface is to
553        provide fast pattern matching, so several sanity checks are not performed.
554        However, feature tests are still performed. The new interface provides
555        1.4x speedup compared to the old one.
556    
557    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
558        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
559        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
560    
561    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
562        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
563        the "old" RFC 2279). Instead, it ended up passing a negative length to
564        pcre_exec().
565    
566    31. Add support for GCC's visibility feature to hide internal functions.
567    
568    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
569        "unknown -C option" after outputting 0 or 1.
570    
571    33. There is now support for generating a code coverage report for the test
572        suite in environments where gcc is the compiler and lcov is installed. This
573        is mainly for the benefit of the developers.
574    
575    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
576        unaddressable using valgrind annotations, allowing valgrind to detect
577        invalid memory accesses. This is mainly for the benefit of the developers.
578    
579    25. (*UTF) can now be used to start a pattern in any of the three libraries.
580    
581    26. Give configure error if --enable-cpp but no C++ compiler found.
582    
583    
584    Version 8.31 06-July-2012
585    -------------------------
586    
587    1.  Fixing a wrong JIT test case and some compiler warnings.
588    
589    2.  Removed a bashism from the RunTest script.
590    
591    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
592        to unsigned type, result still unsigned" that was given by an MS compiler
593        on encountering the code "-sizeof(xxx)".
594    
595    4.  Partial matching support is added to the JIT compiler.
596    
597    5.  Fixed several bugs concerned with partial matching of items that consist
598        of more than one character:
599    
600        (a) /^(..)\1/ did not partially match "aba" because checking references was
601            done on an "all or nothing" basis. This also applied to repeated
602            references.
603    
604        (b) \R did not give a hard partial match if \r was found at the end of the
605            subject.
606    
607        (c) \X did not give a hard partial match after matching one or more
608            characters at the end of the subject.
609    
610        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
611            a partial match for the string "\r".
612    
613        (e) When newline was set to CRLF, the metacharacter "." did not recognize
614            a partial match for a CR character at the end of the subject string.
615    
616    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
617        running pcretest, the text "(JIT)" added to the output whenever JIT is
618        actually used to run the match.
619    
620    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
621        or /S+[+] with a digit between 1 and 7.
622    
623    8.  OP_NOT now supports any UTF character not just single-byte ones.
624    
625    9.  (*MARK) control verb is now supported by the JIT compiler.
626    
627    10. The command "./RunTest list" lists the available tests without actually
628        running any of them. (Because I keep forgetting what they all are.)
629    
630    11. Add PCRE_INFO_MAXLOOKBEHIND.
631    
632    12. Applied a (slightly modified) user-supplied patch that improves performance
633        when the heap is used for recursion (compiled with --disable-stack-for-
634        recursion). Instead of malloc and free for each heap frame each time a
635        logical recursion happens, frames are retained on a chain and re-used where
636        possible. This sometimes gives as much as 30% improvement.
637    
638    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
639        call.
640    
641    14. As documented, (*COMMIT) is now confined to within a positive assertion.
642    
643    15. It is now possible to link pcretest with libedit as an alternative to
644        libreadline.
645    
646    16. (*COMMIT) control verb is now supported by the JIT compiler.
647    
648    17. The Unicode data tables have been updated to Unicode 6.1.0.
649    
650    18. Added --file-list option to pcregrep.
651    
652    19. Added binary file support to pcregrep, including the -a, --binary-files,
653        -I, and --text options.
654    
655    20. The madvise function is renamed for posix_madvise for QNX compatibility
656        reasons. Fixed by Giuseppe D'Angelo.
657    
658    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
659    
660    22. Changed the option for creating symbolic links for 16-bit man pages from
661        -s to -sf so that re-installing does not cause issues.
662    
663    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
664    
665    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
666        matches in certain environments (the workspace was not being correctly
667        retained). Also added to pcre_dfa_exec() a simple plausibility check on
668        some of the workspace data at the beginning of a restart.
669    
670    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
671        was not doing so when it should - probably a typo introduced by SVN 528
672        (change 8.10/14).
673    
674    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
675        \w+ when the character tables indicated that \x{c4} was a word character.
676        There were several related cases, all because the tests for doing a table
677        lookup were testing for characters less than 127 instead of 255.
678    
679    27. If a pattern contains capturing parentheses that are not used in a match,
680        their slots in the ovector are set to -1. For those that are higher than
681        any matched groups, this happens at the end of processing. In the case when
682        there were back references that the ovector was too small to contain
683        (causing temporary malloc'd memory to be used during matching), and the
684        highest capturing number was not used, memory off the end of the ovector
685        was incorrectly being set to -1. (It was using the size of the temporary
686        memory instead of the true size.)
687    
688    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
689        ovector size, it uses memory at the end of the block that it has got.
690    
691    29. Check for an overlong MARK name and give an error at compile time. The
692        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
693    
694    30. JIT compiler update.
695    
696    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
697        Rill for the patch.
698    
699    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
700    
701    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
702    
703    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
704        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
705        was enabled.
706    
707    35. Improve JIT code generation for greedy plus quantifier.
708    
709    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
710        1 to "aa" instead of to an empty string. The bug affected repeated groups
711        that could potentially match an empty string.
712    
713    37. Optimizing single character iterators in JIT.
714    
715    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
716        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
717        codepoints that are too big for the mode are faulted, and in a UTF mode,
718        disallowed codepoints are also faulted.
719    
720    39. If PCRE was compiled with UTF support, in three places in the DFA
721        matcher there was code that should only have been obeyed in UTF mode, but
722        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
723        processing when bytes with values greater than 127 were present. In 16-bit
724        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
725        both cases the values are those that cannot be the first data item in a UTF
726        character. The three items that might have provoked this were recursions,
727        possessively repeated groups, and atomic groups.
728    
729    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
730        and pcregrep, because some OS require shared objects to be explicitly
731        passed to ld, causing the link step to fail if they are not.
732    
733    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
734        mode, patterns that started with \h* or \R* might be incorrectly matched.
735    
736    
737    Version 8.30 04-February-2012
738    -----------------------------
739    
740    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
741        name is defined in ctype.h.
742    
743    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
744        only in quite long subpatterns.
745    
746    3.  Removed the function pcre_info(), which has been obsolete and deprecated
747        since it was replaced by pcre_fullinfo() in February 2000.
748    
749    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
750        match a (*MARK), and the match failed at the start of the subject, a
751        reference to memory before the start of the subject could occur. This bug
752        was introduced by fix 17 of release 8.21.
753    
754    5.  A reference to an unset group with zero minimum repetition was giving
755        totally wrong answers (in non-JavaScript-compatibility mode). For example,
756        /(another)?(\1?)test/ matched against "hello world test". This bug was
757        introduced in release 8.13.
758    
759    6.  Add support for 16-bit character strings (a large amount of work involving
760        many changes and refactorings).
761    
762    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
763        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
764        from a file.
765    
766    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
767        rounding is not applied in this particular case).
768    
769    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
770        if they appear, or are escaped, in patterns.
771    
772    10. Get rid of a number of -Wunused-but-set-variable warnings.
773    
774    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
775        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
776        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
777        also returns the mark "x". This bug applied to capturing parentheses,
778        non-capturing parentheses, and atomic parentheses. It also applied to some
779        assertions.
780    
781    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
782        information out of configure.ac instead of relying on pcre.h.generic, which
783        is not stored in the repository.
784    
785    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
786        -lreadline.
787    
788    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
789    
790    15. Applied Graycode's patch to put the top-level frame on the stack rather
791        than the heap when not using the stack for recursion. This gives a
792        performance improvement in many cases when recursion is not deep.
793    
794    16. Experimental code added to "pcretest -C" to output the stack frame size.
795    
796    
797    Version 8.21 12-Dec-2011
798    ------------------------
799    
800    1.  Updating the JIT compiler.
801    
802    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
803        are added as well.
804    
805    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
806        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
807        calling _pcre_jit_exec. Some extra comments are added.
808    
809    4.  (*MARK) settings inside atomic groups that do not contain any capturing
810        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
811        was introduced by change 18 for 8.20.
812    
813    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
814        ECMA-262 standard.
815    
816    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
817        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
818        This bug was probably introduced by change 9 of 8.13.
819    
820    7.  While fixing 6 above, I noticed that a number of other items were being
821        incorrectly rejected as "not fixed length". This arose partly because newer
822        opcodes had not been added to the fixed-length checking code. I have (a)
823        corrected the bug and added tests for these items, and (b) arranged for an
824        error to occur if an unknown opcode is encountered while checking for fixed
825        length instead of just assuming "not fixed length". The items that were
826        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
827        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
828        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
829    
830    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
831        being incorrectly compiled and would have given unpredicatble results.
832    
833    9.  A possessively repeated subpattern with minimum repeat count greater than
834        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
835        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
836        the first (A) could occur when it should not.
837    
838    10. Add a cast and remove a redundant test from the code.
839    
840    11. JIT should use pcre_malloc/pcre_free for allocation.
841    
842    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
843        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
844        is anything other than /usr, -L is still shown).
845    
846    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
847    
848    14. Perl does not support \N without a following name in a [] class; PCRE now
849        also gives an error.
850    
851    15. If a forward reference was repeated with an upper limit of around 2000,
852        it caused the error "internal error: overran compiling workspace". The
853        maximum number of forward references (including repeats) was limited by the
854        internal workspace, and dependent on the LINK_SIZE. The code has been
855        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
856        the default depends on LINK_SIZE. There is a new upper limit (for safety)
857        of around 200,000 forward references. While doing this, I also speeded up
858        the filling in of repeated forward references.
859    
860    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
861        incorrectly expecting the subject to contain another "a" after the start.
862    
863    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
864        in the match, the SKIP should be ignored. This was not happening; instead
865        the SKIP was being treated as NOMATCH. For patterns such as
866        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
867        tested.
868    
869    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
870        now much more compatible with Perl, in particular in cases where the result
871        is a non-match for a non-anchored pattern. For example, if
872        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
873        "m", where previously it did not return a name. A side effect of this
874        change is that for partial matches, the last encountered mark name is
875        returned, as for non matches. A number of tests that were previously not
876        Perl-compatible have been moved into the Perl-compatible test files. The
877        refactoring has had the pleasing side effect of removing one argument from
878        the match() function, thus reducing its stack requirements.
879    
880    19. If the /S+ option was used in pcretest to study a pattern using JIT,
881        subsequent uses of /S (without +) incorrectly behaved like /S+.
882    
883    21. Retrieve executable code size support for the JIT compiler and fixing
884        some warnings.
885    
886    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
887        not work when the shorter character appeared right at the end of the
888        subject string.
889    
890    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
891        systems.
892    
893    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
894        output it when the /M option is used in pcretest.
895    
896    25. The CheckMan script was not being included in the distribution. Also, added
897        an explicit "perl" to run Perl scripts from the PrepareRelease script
898        because this is reportedly needed in Windows.
899    
900    26. If study data was being save in a file and studying had not found a set of
901        "starts with" bytes for the pattern, the data written to the file (though
902        never used) was taken from uninitialized memory and so caused valgrind to
903        complain.
904    
905    27. Updated RunTest.bat as provided by Sheri Pierce.
906    
907    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
908    
909    29. Computation of memory usage for the table of capturing group names was
910        giving an unnecessarily large value.
911    
912    
913    Version 8.20 21-Oct-2011
914    ------------------------
915    
916    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
917        a POSIX class. After further experiments with Perl, which convinced me that
918        Perl has bugs and confusions, a closing square bracket is no longer allowed
919        in a POSIX name. This bug also affected patterns with classes that started
920        with full stops.
921    
922    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
923        captured substring, but while checking the failing first alternative,
924        substring 1 is temporarily captured. If the output vector supplied to
925        pcre_exec() was not big enough for this capture, the yield of the function
926        was still zero ("insufficient space for captured substrings"). This cannot
927        be totally fixed without adding another stack variable, which seems a lot
928        of expense for a edge case. However, I have improved the situation in cases
929        such as /(a)(b)x|abc/ matched against "abc", where the return code
930        indicates that fewer than the maximum number of slots in the ovector have
931        been set.
932    
933    3.  Related to (2) above: when there are more back references in a pattern than
934        slots in the output vector, pcre_exec() uses temporary memory during
935        matching, and copies in the captures as far as possible afterwards. It was
936        using the entire output vector, but this conflicts with the specification
937        that only 2/3 is used for passing back captured substrings. Now it uses
938        only the first 2/3, for compatibility. This is, of course, another edge
939        case.
940    
941    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
942        main code base, and can be used by building with --enable-jit. When this is
943        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
944        runtime --no-jit option is given.
945    
946    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
947        ovector, the return from the function was zero, implying that there were
948        other matches that did not fit. The correct "exactly full" value is now
949        returned.
950    
951    6.  If a subpattern that was called recursively or as a subroutine contained
952        (*PRUNE) or any other control that caused it to give a non-standard return,
953        invalid errors such as "Error -26 (nested recursion at the same subject
954        position)" or even infinite loops could occur.
955    
956    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
957        computing the minimum length on reaching *ACCEPT, and so ended up with the
958        wrong value of 1 rather than 0. Further investigation indicates that
959        computing a minimum subject length in the presence of *ACCEPT is difficult
960        (think back references, subroutine calls), and so I have changed the code
961        so that no minimum is registered for a pattern that contains *ACCEPT.
962    
963    8.  If (*THEN) was present in the first (true) branch of a conditional group,
964        it was not handled as intended. [But see 16 below.]
965    
966    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
967        Sheri Pierce.
968    
969    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
970        the first byte in a match must be "a".
971    
972    11. Change 17 for 8.13 increased the recursion depth for patterns like
973        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
974        pattern contains any instances of (*THEN). If it does not, the old
975        optimizations are restored. It would be nice to do this on a per-group
976        basis, but at the moment that is not feasible.
977    
978    12. In some environments, the output of pcretest -C is CRLF terminated. This
979        broke RunTest's code that checks for the link size. A single white space
980        character after the value is now allowed for.
981    
982    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
983        For "fr", it uses the Windows-specific input and output files.
984    
985    14. If (*THEN) appeared in a group that was called recursively or as a
986        subroutine, it did not work as intended. [But see next item.]
987    
988    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
989        pattern fragments (but not containing any | characters). If A and B are
990        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
991        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
992        D. In other words, Perl considers parentheses that do not contain any |
993        characters to be part of a surrounding alternative, whereas PCRE was
994        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
995        differently. PCRE now behaves in the same way as Perl, except in the case
996        of subroutine/recursion calls such as (?1) which have in any case always
997        been different (but PCRE had them first :-).
998    
999    16. Related to 15 above: Perl does not treat the | in a conditional group as
1000        creating alternatives. Such a group is treated in the same way as an
1001        ordinary group without any | characters when processing (*THEN). PCRE has
1002        been changed to match Perl's behaviour.
1003    
1004    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1005        RunGrepTest script failed.
1006    
1007    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1008        inevitable for groups that contain captures, but it can lead to a lot of
1009        stack use in large patterns. The old behaviour has been restored for atomic
1010        groups that do not contain any capturing parentheses.
1011    
1012    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1013        suppress the check for a minimum subject length at run time. (If it was
1014        given to pcre_exec() or pcre_dfa_exec() it did work.)
1015    
1016    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1017        fail to work when decoding hex characters in data strings in EBCDIC
1018        environments.
1019    
1020    21. It appears that in at least one Mac OS environment, the isxdigit() function
1021        is implemented as a macro that evaluates to its argument more than once,
1022        contravening the C 90 Standard (I haven't checked a later standard). There
1023        was an instance in pcretest which caused it to go wrong when processing
1024        \x{...} escapes in subject strings. The has been rewritten to avoid using
1025        things like p++ in the argument of isxdigit().
1026    
1027    
1028    Version 8.13 16-Aug-2011
1029    ------------------------
1030    
1031    1.  The Unicode data tables have been updated to Unicode 6.0.0.
1032    
1033    2.  Two minor typos in pcre_internal.h have been fixed.
1034    
1035    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1036        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1037        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1038    
1039    4.  There were a number of related bugs in the code for matching backrefences
1040        caselessly in UTF-8 mode when codes for the characters concerned were
1041        different numbers of bytes. For example, U+023A and U+2C65 are an upper
1042        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1043        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1044        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1045        2-byte code at the end of the subject (it thought there wasn't enough data
1046        left).
1047    
1048    5.  Comprehensive information about what went wrong is now returned by
1049        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1050        as the output vector has at least 2 elements. The offset of the start of
1051        the failing character and a reason code are placed in the vector.
1052    
1053    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1054        now returned is for the first byte of the failing character, instead of the
1055        last byte inspected. This is an incompatible change, but I hope it is small
1056        enough not to be a problem. It makes the returned offset consistent with
1057        pcre_exec() and pcre_dfa_exec().
1058    
1059    7.  pcretest now gives a text phrase as well as the error number when
1060        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1061        failure, the offset and reason code are output.
1062    
1063    8.  When \R was used with a maximizing quantifier it failed to skip backwards
1064        over a \r\n pair if the subsequent match failed. Instead, it just skipped
1065        back over a single character (\n). This seems wrong (because it treated the
1066        two characters as a single entity when going forwards), conflicts with the
1067        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1068        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1069        has been changed.
1070    
1071    9.  Some internal refactoring has changed the processing so that the handling
1072        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1073        time (the PCRE_DOTALL option was changed this way some time ago: version
1074        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1075        which was always a bit of a fudge. It also means that there is one less
1076        argument for the match() function, which reduces its stack requirements
1077        slightly. This change also fixes an incompatibility with Perl: the pattern
1078        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1079    
1080    10. More internal refactoring has drastically reduced the number of recursive
1081        calls to match() for possessively repeated groups such as (abc)++ when
1082        using pcre_exec().
1083    
1084    11. While implementing 10, a number of bugs in the handling of groups were
1085        discovered and fixed:
1086    
1087        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1088        (a|)*(?1) gave a compile-time internal error.
1089        ((a|)+)+  did not notice that the outer group could match an empty string.
1090        (^a|^)+   was not marked as anchored.
1091        (.*a|.*)+ was not marked as matching at start or after a newline.
1092    
1093    12. Yet more internal refactoring has removed another argument from the match()
1094        function. Special calls to this function are now indicated by setting a
1095        value in a variable in the "match data" data block.
1096    
1097    13. Be more explicit in pcre_study() instead of relying on "default" for
1098        opcodes that mean there is no starting character; this means that when new
1099        ones are added and accidentally left out of pcre_study(), testing should
1100        pick them up.
1101    
1102    14. The -s option of pcretest has been documented for ages as being an old
1103        synonym of -m (show memory usage). I have changed it to mean "force study
1104        for every regex", that is, assume /S for every regex. This is similar to -i
1105        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1106        using it. It makes it easier to run collections of tests with and without
1107        study enabled, and thereby test pcre_study() more easily. All the standard
1108        tests are now run with and without -s (but some patterns can be marked as
1109        "never study" - see 20 below).
1110    
1111    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1112        restoration of the capturing data to the outer values was not happening
1113        correctly.
1114    
1115    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1116        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1117        pattern had matched an empty string, and so incorrectly returned a no
1118        match.
1119    
1120    17. There was optimizing code for the last branch of non-capturing parentheses,
1121        and also for the obeyed branch of a conditional subexpression, which used
1122        tail recursion to cut down on stack usage. Unfortunately, now that there is
1123        the possibility of (*THEN) occurring in these branches, tail recursion is
1124        no longer possible because the return has to be checked for (*THEN). These
1125        two optimizations have therefore been removed. [But see 8.20/11 above.]
1126    
1127    18. If a pattern containing \R was studied, it was assumed that \R always
1128        matched two bytes, thus causing the minimum subject length to be
1129        incorrectly computed because \R can also match just one byte.
1130    
1131    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1132        was incorrectly computed.
1133    
1134    20. If /S is present twice on a test pattern in pcretest input, it now
1135        *disables* studying, thereby overriding the use of -s on the command line
1136        (see 14 above). This is necessary for one or two tests to keep the output
1137        identical in both cases.
1138    
1139    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1140        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1141    
1142    22. When an atomic group that contained a capturing parenthesis was
1143        successfully matched, but the branch in which it appeared failed, the
1144        capturing was not being forgotten if a higher numbered group was later
1145        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1146        group 1 to "a", when in fact it should be unset. This applied to multi-
1147        branched capturing and non-capturing groups, repeated or not, and also to
1148        positive assertions (capturing in negative assertions does not happen
1149        in PCRE) and also to nested atomic groups.
1150    
1151    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1152        subject after a captured substring, to make it easier to tell which of a
1153        number of identical substrings has been captured.
1154    
1155    24. The way atomic groups are processed by pcre_exec() has been changed so that
1156        if they are repeated, backtracking one repetition now resets captured
1157        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1158        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1159        "aaa". Previously, it would have been "a". As part of this code
1160        refactoring, the way recursive calls are handled has also been changed.
1161    
1162    25. If an assertion condition captured any substrings, they were not passed
1163        back unless some other capturing happened later. For example, if
1164        (?(?=(a))a) was matched against "a", no capturing was returned.
1165    
1166    26. When studying a pattern that contained subroutine calls or assertions,
1167        the code for finding the minimum length of a possible match was handling
1168        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1169        group 1 called group 2 while simultaneously a separate group 2 called group
1170        1). A stack overflow occurred in this case. I have fixed this by limiting
1171        the recursion depth to 10.
1172    
1173    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1174        Fortmann. This supports explicit test numbers on the command line, and has
1175        argument validation and error reporting.
1176    
1177    28. An instance of \X with an unlimited repeat could fail if at any point the
1178        first character it looked at was a mark character.
1179    
1180    29. Some minor code refactoring concerning Unicode properties and scripts
1181        should reduce the stack requirement of match() slightly.
1182    
1183    30. Added the '=' option to pcretest to check the setting of unused capturing
1184        slots at the end of the pattern, which are documented as being -1, but are
1185        not included in the return count.
1186    
1187    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1188        compiled something random. Now it gives a compile-time error (as does
1189        Perl).
1190    
1191    32. A *MARK encountered during the processing of a positive assertion is now
1192        recorded and passed back (compatible with Perl).
1193    
1194    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1195        had alternative anchored branches, the search for a second match in a line
1196        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1197        matched the line "0102" twice. The same bug affected patterns that started
1198        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1199        twice.
1200    
1201    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1202        does, and because of capturing effects, quantifying parenthesized
1203        assertions may at times be useful. Quantifiers are now allowed for
1204        parenthesized assertions.
1205    
1206    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1207    
1208    36. \g was being checked for fancy things in a character class, when it should
1209        just be a literal "g".
1210    
1211    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1212        appearance of a nested POSIX class supersedes an apparent external class.
1213        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1214        unescaped square brackets may also appear as part of class names. For
1215        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1216        more like Perl. (But see 8.20/1 above.)
1217    
1218    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1219        was because it thought it was \N{name}, which is not supported).
1220    
1221    39. Add minix to OS list not supporting the -S option in pcretest.
1222    
1223    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1224        cannot analyze patterns in sufficient detail to catch mutual recursions
1225        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1226        subgroup is called recursively as a subpattern for a second time at the
1227        same position in the subject string. In previous releases this might have
1228        been caught by the recursion limit, or it might have run out of stack.
1229    
1230    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1231        happen only once. PCRE was, however incorrectly giving a compile time error
1232        "recursive call could loop indefinitely" because it cannot analyze the
1233        pattern in sufficient detail. The compile time test no longer happens when
1234        PCRE is compiling a conditional subpattern, but actual runaway loops are
1235        now caught at runtime (see 40 above).
1236    
1237    42. It seems that Perl allows any characters other than a closing parenthesis
1238        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1239        has been changed to be the same.
1240    
1241    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1242        as not to get warnings when autogen.sh is called. Also changed
1243        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1244    
1245    44. To help people who use pcregrep to scan files containing exceedingly long
1246        lines, the following changes have been made:
1247    
1248        (a) The default value of the buffer size parameter has been increased from
1249            8K to 20K. (The actual buffer used is three times this size.)
1250    
1251        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1252            PCRE is built.
1253    
1254        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1255            to be set at run time.
1256    
1257        (d) Numerical values in pcregrep options can be followed by K or M, for
1258            example --buffer-size=50K.
1259    
1260        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1261            given and the return code is set to 2.
1262    
1263    45. Add a pointer to the latest mark to the callout data block.
1264    
1265    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1266        partial match of an empty string instead of no match. This was specific to
1267        the use of ".".
1268    
1269    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1270        complete match instead of a partial match. This bug was dependent on both
1271        the PCRE_UTF8 and PCRE_DOTALL options being set.
1272    
1273    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1274        starting byte set, because \b was not being ignored.
1275    
1276    
1277    Version 8.12 15-Jan-2011
1278    ------------------------
1279    
1280    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1281        checks for such things as part of the documentation building process.
1282    
1283    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1284        --match-limit and --recursion-limit options (added for 8.11). In
1285        particular, this made one of the standard tests fail. (The integer value
1286        went into the wrong half of a long int.)
1287    
1288    3.  If the --colour option was given to pcregrep with -v (invert match), it
1289        did strange things, either producing crazy output, or crashing. It should,
1290        of course, ignore a request for colour when reporting lines that do not
1291        match.
1292    
1293    4.  Another pcregrep bug caused similar problems if --colour was specified with
1294        -M (multiline) and the pattern match finished with a line ending.
1295    
1296    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1297        matched in multiline mode, the following line was shown as part of the
1298        match. This seems wrong, so I have changed it.
1299    
1300    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1301        the check for further matches in the same line (so they could be coloured)
1302        to overrun the end of the current line. If another match was found, it was
1303        incorrectly shown (and then shown again when found in the next line).
1304    
1305    7.  If pcregrep was compiled under Windows, there was a reference to the
1306        function pcregrep_exit() before it was defined. I am assuming this was
1307        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1308        reported by a user. I've moved the definition above the reference.
1309    
1310    
1311    Version 8.11 10-Dec-2010
1312    ------------------------
1313    
1314    1.  (*THEN) was not working properly if there were untried alternatives prior
1315        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1316        backtracked to try for "b" instead of moving to the next alternative branch
1317        at the same level (in this case, to look for "c"). The Perl documentation
1318        is clear that when (*THEN) is backtracked onto, it goes to the "next
1319        alternative in the innermost enclosing group".
1320    
1321    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1322        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1323        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1324        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1325        (*THEN).
1326    
1327    3.  If \s appeared in a character class, it removed the VT character from
1328        the class, even if it had been included by some previous item, for example
1329        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1330        of \s, but is part of the POSIX "space" class.)
1331    
1332    4.  A partial match never returns an empty string (because you can always
1333        match an empty string at the end of the subject); however the checking for
1334        an empty string was starting at the "start of match" point. This has been
1335        changed to the "earliest inspected character" point, because the returned
1336        data for a partial match starts at this character. This means that, for
1337        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1338        (previously it gave "no match").
1339    
1340    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1341        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1342        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1343        has an implication that the given string is incomplete (because a partial
1344        match is preferred over a full match). For this reason, these items now
1345        give a partial match in this situation. [Aside: previously, the one case
1346        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1347        match rather than a full match, which was wrong by the old rules, but is
1348        now correct.]
1349    
1350    6.  There was a bug in the handling of #-introduced comments, recognized when
1351        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1352        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1353        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1354        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1355        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1356        places in pcre_compile().
1357    
1358    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1359        comments when looking ahead for named forward references to subpatterns,
1360        the only newline sequence it recognized was NL. It now handles newlines
1361        according to the set newline convention.
1362    
1363    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1364        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1365        cater for a lack of strerror(). These oversights have been fixed.
1366    
1367    9.  Added --match-limit and --recursion-limit to pcregrep.
1368    
1369    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1370    
1371    11. When the -o option was used, pcregrep was setting a return code of 1, even
1372        when matches were found, and --line-buffered was not being honoured.
1373    
1374    12. Added an optional parentheses number to the -o and --only-matching options
1375        of pcregrep.
1376    
1377    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1378        can match an empty string. The code to do it in pcretest and pcredemo
1379        needed fixing:
1380    
1381        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1382            only one byte after an empty string match just before CRLF (this case
1383            just got forgotten; "any" and "anycrlf" were OK).
1384    
1385        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1386            mode when an empty string match preceded an ASCII character followed by
1387            a non-ASCII character. (The code for advancing by one character rather
1388            than one byte was nonsense.)
1389    
1390        (c) The pcredemo.c sample program did not have any code at all to handle
1391            the cases when CRLF is a valid newline sequence.
1392    
1393    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1394        as a starting offset was within the subject string. There is now a new
1395        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1396        negative or greater than the length of the string. In order to test this,
1397        pcretest is extended to allow the setting of negative starting offsets.
1398    
1399    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1400        starting offset points to the beginning of a UTF-8 character was
1401        unnecessarily clumsy. I tidied it up.
1402    
1403    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1404        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1405    
1406    17. Nobody had reported that the --include_dir option, which was added in
1407        release 7.7 should have been called --include-dir (hyphen, not underscore)
1408        for compatibility with GNU grep. I have changed it to --include-dir, but
1409        left --include_dir as an undocumented synonym, and the same for
1410        --exclude-dir, though that is not available in GNU grep, at least as of
1411        release 2.5.4.
1412    
1413    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1414        characters from a string of bytes) have been redefined so as not to use
1415        loops, in order to improve performance in some environments. At the same
1416        time, I abstracted some of the common code into auxiliary macros to save
1417        repetition (this should not affect the compiled code).
1418    
1419    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1420        compile-time error is now given if \c is not followed by an ASCII
1421        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1422        different, and any byte value is allowed.)
1423    
1424    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1425        START_OPTIMIZE option, which is now allowed at compile time - but just
1426        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1427        to pcregrep and other applications that have no direct access to PCRE
1428        options. The new /Y option in pcretest sets this option when calling
1429        pcre_compile().
1430    
1431    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1432        back references. Groups containing recursive back references were forced to
1433        be atomic by that change, but in the case of named groups, the amount of
1434        memory required was incorrectly computed, leading to "Failed: internal
1435        error: code overflow". This has been fixed.
1436    
1437    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1438        pcretest.c, to avoid build problems in some Borland environments.
1439    
1440    
1441    Version 8.10 25-Jun-2010
1442    ------------------------
1443    
1444    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1445        THEN.
1446    
1447    2.  (*ACCEPT) was not working when inside an atomic group.
1448    
1449    3.  Inside a character class, \B is treated as a literal by default, but
1450        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1451        causes the error). The code is unchanged, but I tidied the documentation.
1452    
1453    4.  Inside a character class, PCRE always treated \R and \X as literals,
1454        whereas Perl faults them if its -w option is set. I have changed PCRE so
1455        that it faults them when PCRE_EXTRA is set.
1456    
1457    5.  Added support for \N, which always matches any character other than
1458        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1459    
1460    6.  When compiling pcregrep with newer versions of gcc which may have
1461        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1462        declared with attribute warn_unused_result" were given. Just casting the
1463        result to (void) does not stop the warnings; a more elaborate fudge is
1464        needed. I've used a macro to implement this.
1465    
1466    7.  Minor change to pcretest.c to avoid a compiler warning.
1467    
1468    8.  Added four artifical Unicode properties to help with an option to make
1469        \s etc use properties (see next item). The new properties are: Xan
1470        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1471    
1472    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1473        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1474        this option. Modified pcretest to add /W to test this facility. Added
1475        REG_UCP to make it available via the POSIX interface.
1476    
1477    10. Added --line-buffered to pcregrep.
1478    
1479    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1480        studied, and the match started with a letter with a code point greater than
1481        127 whose first byte was different to the first byte of the other case of
1482        the letter, the other case of this starting letter was not recognized
1483        (#976).
1484    
1485    12. If a pattern that was studied started with a repeated Unicode property
1486        test, for example, \p{Nd}+, there was the theoretical possibility of
1487        setting up an incorrect bitmap of starting bytes, but fortunately it could
1488        not have actually happened in practice until change 8 above was made (it
1489        added property types that matched character-matching opcodes).
1490    
1491    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1492        possible starting bytes for non-anchored patterns.
1493    
1494    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1495        \R, and also a number of cases that involve Unicode properties, both
1496        explicit and implicit when PCRE_UCP is set.
1497    
1498    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1499        input, it could crash or give wrong results if characters with values
1500        greater than 0xc0 were present in the subject string. (Detail: it assumed
1501        UTF-8 input when processing these items.)
1502    
1503    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1504        size_t is 64-bit (#991).
1505    
1506    17. Added a check for running out of memory when PCRE is compiled with
1507        --disable-stack-for-recursion (#990).
1508    
1509    18. If the last data line in a file for pcretest does not have a newline on
1510        the end, a newline was missing in the output.
1511    
1512    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1513        less than 128) in its various bitmaps. However, there is a facility for
1514        generating tables according to the current locale when PCRE is compiled. It
1515        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1516        characters, are recognized by isspace() and therefore were getting set in
1517        these tables, and indeed these tables seem to approximate to ISO 8859. This
1518        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1519        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1520        which of course cannot start UTF-8 characters. I have changed the code so
1521        that only real ASCII characters (less than 128) and the correct starting
1522        bytes for UTF-8 encodings are set for characters greater than 127 when in
1523        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1524        altogether.)
1525    
1526    20. Added the /T option to pcretest so as to be able to run tests with non-
1527        standard character tables, thus making it possible to include the tests
1528        used for 19 above in the standard set of tests.
1529    
1530    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1531        reference to a subpattern the other side of a comment that contains an
1532        opening parenthesis caused either an internal compiling error, or a
1533        reference to the wrong subpattern.
1534    
1535    
1536    Version 8.02 19-Mar-2010
1537  ------------------------  ------------------------
1538    
1539  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.
1540    
1541    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1542        configured.
1543    
1544    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1545        original author of that file, following a query about its status.
1546    
1547    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1548        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1549    
1550    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1551        quantifier applied to a forward-referencing subroutine call, could compile
1552        incorrect code or give the error "internal error: previously-checked
1553        referenced subpattern not found".
1554    
1555    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1556        variables to point to external functions. For these systems, therefore,
1557        pcre_malloc etc. are now initialized to local functions that call the
1558        relevant global functions.
1559    
1560    7.  There were two entries missing in the vectors called coptable and poptable
1561        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1562        I've fixed the data, and added a kludgy way of testing at compile time that
1563        the lengths are correct (equal to the number of opcodes).
1564    
1565    8.  Following on from 7, I added a similar kludge to check the length of the
1566        eint vector in pcreposix.c.
1567    
1568    9.  Error texts for pcre_compile() are held as one long string to avoid too
1569        much relocation at load time. To find a text, the string is searched,
1570        counting zeros. There was no check for running off the end of the string,
1571        which could happen if a new error number was added without updating the
1572        string.
1573    
1574    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1575    
1576    11. \K was not working if it appeared in an atomic group or in a group that
1577        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1578        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1579        the assertion is positive, but not if it is negative.
1580    
1581    12. Change 11 fortuitously reduced the size of the stack frame used in the
1582        "match()" function of pcre_exec.c by one pointer. Forthcoming
1583        implementation of support for (*MARK) will need an extra pointer on the
1584        stack; I have reserved it now, so that the stack frame size does not
1585        decrease.
1586    
1587    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1588        item in branch that calls a recursion is a subroutine call - as in the
1589        second branch in the above example - was incorrectly given the compile-
1590        time error "recursive call could loop indefinitely" because pcre_compile()
1591        was not correctly checking the subroutine for matching a non-empty string.
1592    
1593    14. The checks for overrunning compiling workspace could trigger after an
1594        overrun had occurred. This is a "should never occur" error, but it can be
1595        triggered by pathological patterns such as hundreds of nested parentheses.
1596        The checks now trigger 100 bytes before the end of the workspace.
1597    
1598    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1599    
1600    
1601  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
1602  ------------------------  ------------------------
# Line 333  Version 7.9 11-Apr-09 Line 1924  Version 7.9 11-Apr-09
1924  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
1925      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
1926      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1927      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1928        8.33.]
1929    
1930  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
1931      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 576  Version 7.7 07-May-08 Line 2168  Version 7.7 07-May-08
2168      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2169      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2170      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2171      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2172      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2173      was subsequently set up correctly.)      was subsequently set up correctly.)
2174    

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