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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.20  Version 8.35-RC1 14-March-2014
5  ------------  ------------------------------
6    
7  1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had  1.  A new flag is set, when property checks are present in an XCLASS.
8  a POSIX class. After further experiments with Perl, which convinced me that      When this flag is not set, PCRE can perform certain optimizations
9  Perl has bugs and confusions, a closing square bracket is no longer allowed in      such as studying these XCLASS-es.
10  a POSIX name.  
11    2.  The auto-possessification of character sets were improved: a normal
12        and an extended character set can be compared now. Furthermore
13        the JIT compiler optimizes more character set checks.
14    
15    3.  Got rid of some compiler warnings for potentially uninitialized variables
16        that show up only when compiled with -O2.
17    
18    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
19        of a match later then the end of the match. The pcretest program was not
20        handling the case sensibly - it was outputting from the start to the next
21        binary zero. It now reports this situation in a message, and outputs the
22        text from the end to the start.
23    
24    5.  Fast forward search is improved in JIT. Instead of the first three
25        characters, any three characters with fixed position can be searched.
26        Search order: first, last, middle.
27    
28    6.  Improve character range checks in JIT. Characters are read by an inprecise
29        function now, which returns with an unknown value if the character code is
30        above a certain treshold (e.g: 256). The only limitation is that the value
31        must be bigger than the treshold as well. This function is useful, when
32        the characters above the treshold are handled in the same way.
33    
34    7.  The macros whose names start with RAWUCHAR are placeholders for a future
35        mode in which only the bottom 21 bits of 32-bit data items are used. To
36        make this more memorable for those maintaining the code, the names have
37        been changed to start with UCHAR21, and an extensive comment has been added
38        to their definition.
39    
40    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
41        to the export list in Makefile.am (they were accidentally omitted from the
42        8.34 tarball).
43    
44    9.  The informational output from pcretest used the phrase "starting byte set"
45        which is inappropriate for the 16-bit and 32-bit libraries. As the output
46        for "first char" and "need char" really means "non-UTF-char", I've changed
47        "byte" to "char", and slightly reworded the output. The documentation about
48        these values has also been (I hope) clarified.
49    
50    10. Another JIT related optimization: use table jumps for selecting the correct
51        backtracking path, when more than four alternatives are present inside a
52        bracket.
53    
54    11. Empty match is not possible, when the minimum length is greater than zero,
55        and there is no \K in the pattern. JIT should avoid empty match checks in
56        such cases.
57    
58    12. In a caseless character class with UCP support, when a character with more
59        than one alternative case was not the first character of a range, not all
60        the alternative cases were added to the class. For example, s and \x{17f}
61        are both alternative cases for S: the class [RST] was handled correctly,
62        but [R-T] was not.
63    
64    13. The configure.ac file always checked for pthread support when JIT was
65        enabled. This is not used in Windows, so I have put this test inside a
66        check for the presence of windows.h (which was already tested for).
67    
68    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
69        The algorithm provides a way to skip certain starting offsets, and usually
70        faster than linear prefix searches.
71    
72    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
73        as for 'fr_FR' and 'french'. For some reason, however, it then used the
74        Windows-specific input and output files, which have 'french' screwed in.
75        So this could never have worked. One of the problems with locales is that
76        they aren't always the same. I have now updated RunTest so that it checks
77        the output of the locale test (test 3) against three different output
78        files, and it allows the test to pass if any one of them matches. With luck
79        this should make the test pass on some versions of Solaris where it was
80        failing. Because of the uncertainty, the script did not used to stop if
81        test 3 failed; it now does. If further versions of a French locale ever
82        come to light, they can now easily be added.
83    
84    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
85        there was a message during ./configure, but it did not stop. This now
86        provokes an error. The invalid example in README has been corrected.
87        If a value less than the minimum is given, the minimum value has always
88        been used, but now a warning is given.
89    
90    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
91        was a bug in the test system, which is now fixed. Also, the list of various
92        configurations that are tested for each release did not have one with both
93        16/32 bits and --enable-bar-anycrlf. It now does.
94    
95    18. pcretest was missing "-C bsr" for displaying the \R default setting.
96    
97    19. Little endian PowerPC systems are supported now by the JIT compiler.
98    
99    20. The fast forward newline mechanism could enter to an infinite loop on
100        certain invalid UTF-8 input. Although we don't support these cases
101        this issue can be fixed by a performance optimization.
102    
103    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
104        not take account if existing stack usage. There is now a new global
105        variable called pcre_stack_guard that can be set to point to an external
106        function to check stack availability. It is called at the start of
107        processing every parenthesized group.
108    
109    22. A typo in the code meant that in ungreedy mode the max/min qualifier
110        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
111        not match "ab".
112    
113    23. When UTF was disabled, the JIT program reported some incorrect compile
114        errors. These messages are silenced now.
115    
116    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
117        compiler.
118    
119    
120    Version 8.34 15-December-2013
121    -----------------------------
122    
123    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
124        executable memory. Patch inspired by Carsten Klein.
125    
126    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
127        this macro is never tested and has no effect, because the work to support
128        coverage involves only compiling and linking options and special targets in
129        the Makefile. The comment in config.h implied that defining the macro would
130        enable coverage support, which is totally false. There was also support for
131        setting this macro in the CMake files (my fault, I just copied it from
132        configure). SUPPORT_GCOV has now been removed.
133    
134    3.  Make a small performance improvement in strlen16() and strlen32() in
135        pcretest.
136    
137    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
138        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
139        these cases). There was also one in pcretest.c.
140    
141    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
142    
143    6.  In UTF mode, the code for checking whether a group could match an empty
144        string (which is used for indefinitely repeated groups to allow for
145        breaking an infinite loop) was broken when the group contained a repeated
146        negated single-character class with a character that occupied more than one
147        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
148        UTF-8 mode). The effect was undefined: the group might or might not be
149        deemed as matching an empty string, or the program might have crashed.
150    
151    7.  The code for checking whether a group could match an empty string was not
152        recognizing that \h, \H, \v, \V, and \R must match a character.
153    
154    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
155        an empty string. If it can, pcretest shows this in its information output.
156    
157    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
158        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
159        matched by pcre_exec() without using JIT:
160    
161        (a) If the rest of the pattern did not match after a maximal run of
162            grapheme clusters, the code for backing up to try with fewer of them
163            did not always back up over a full grapheme when characters that do not
164            have the modifier quality were involved, e.g. Hangul syllables.
165    
166        (b) If the match point in a subject started with modifier character, and
167            there was no match, the code could incorrectly back up beyond the match
168            point, and potentially beyond the first character in the subject,
169            leading to a segfault or an incorrect match result.
170    
171    10. A conditional group with an assertion condition could lead to PCRE
172        recording an incorrect first data item for a match if no other first data
173        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
174        first data item, and therefore matched "ca" after "c" instead of at the
175        start.
176    
177    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
178        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
179    
180    12. The source of pcregrep now includes z/OS-specific code so that it can be
181        compiled for z/OS as part of the special z/OS distribution.
182    
183    13. Added the -T and -TM options to pcretest.
184    
185    14. The code in pcre_compile.c for creating the table of named capturing groups
186        has been refactored. Instead of creating the table dynamically during the
187        actual compiling pass, the information is remembered during the pre-compile
188        pass (on the stack unless there are more than 20 named groups, in which
189        case malloc() is used) and the whole table is created before the actual
190        compile happens. This has simplified the code (it is now nearly 150 lines
191        shorter) and prepared the way for better handling of references to groups
192        with duplicate names.
193    
194    15. A back reference to a named subpattern when there is more than one of the
195        same name now checks them in the order in which they appear in the pattern.
196        The first one that is set is used for the reference. Previously only the
197        first one was inspected. This change makes PCRE more compatible with Perl.
198    
199    16. Unicode character properties were updated from Unicode 6.3.0.
200    
201    17. The compile-time code for auto-possessification has been refactored, based
202        on a patch by Zoltan Herczeg. It now happens after instead of during
203        compilation. The code is cleaner, and more cases are handled. The option
204        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
205        options in pcretest are provided to set it. It can also be set by
206        (*NO_AUTO_POSSESS) at the start of a pattern.
207    
208    18. The character VT has been added to the default ("C" locale) set of
209        characters that match \s and are generally treated as white space,
210        following this same change in Perl 5.18. There is now no difference between
211        "Perl space" and "POSIX space". Whether VT is treated as white space in
212        other locales depends on the locale.
213    
214    19. The code for checking named groups as conditions, either for being set or
215        for being recursed, has been refactored (this is related to 14 and 15
216        above). Processing unduplicated named groups should now be as fast at
217        numerical groups, and processing duplicated groups should be faster than
218        before.
219    
220    20. Two patches to the CMake build system, by Alexander Barkov:
221    
222          (1) Replace the "source" command by "." in CMakeLists.txt because
223              "source" is a bash-ism.
224    
225          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
226              without these the CMake build does not work on Solaris.
227    
228    21. Perl has changed its handling of \8 and \9. If there is no previously
229        encountered capturing group of those numbers, they are treated as the
230        literal characters 8 and 9 instead of a binary zero followed by the
231        literals. PCRE now does the same.
232    
233    22. Following Perl, added \o{} to specify codepoints in octal, making it
234        possible to specify values greater than 0777 and also making them
235        unambiguous.
236    
237    23. Perl now gives an error for missing closing braces after \x{... instead of
238        treating the string as literal. PCRE now does the same.
239    
240    24. RunTest used to grumble if an inappropriate test was selected explicitly,
241        but just skip it when running all tests. This make it awkward to run ranges
242        of tests when one of them was inappropriate. Now it just skips any
243        inappropriate tests, as it always did when running all tests.
244    
245    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
246        character types such as \d or \w, too many callouts were inserted, and the
247        data that they returned was rubbish.
248    
249    26. In UCP mode, \s was not matching two of the characters that Perl matches,
250        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
251        were matched by \h. The code has now been refactored so that the lists of
252        the horizontal and vertical whitespace characters used for \h and \v (which
253        are defined only in one place) are now also used for \s.
254    
255    27. Add JIT support for the 64 bit TileGX architecture.
256        Patch by Jiong Wang (Tilera Corporation).
257    
258    28. Possessive quantifiers for classes (both explicit and automatically
259        generated) now use special opcodes instead of wrapping in ONCE brackets.
260    
261    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
262        (because it's meaningless), this was not happening when PCRE_CASELESS was
263        set. Not wrong, but inefficient.
264    
265    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
266        properties for \w, \d, etc) is present in a test regex. Otherwise if the
267        test contains no characters greater than 255, Perl doesn't realise it
268        should be using Unicode semantics.
269    
270    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
271        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
272        does in Unicode mode.
273    
274    32. Added the "forbid" facility to pcretest so that putting tests into the
275        wrong test files can sometimes be quickly detected.
276    
277    33. There is now a limit (default 250) on the depth of nesting of parentheses.
278        This limit is imposed to control the amount of system stack used at compile
279        time. It can be changed at build time by --with-parens-nest-limit=xxx or
280        the equivalent in CMake.
281    
282    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
283        errors. Perl warns for these when in warning mode, but PCRE has no facility
284        for giving warnings.
285    
286    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
287        However, this was not working for (?!) because it is optimized to (*FAIL),
288        for which PCRE does not allow quantifiers. The optimization is now disabled
289        when a quantifier follows (?!). I can't see any use for this, but it makes
290        things uniform.
291    
292    36. Perl no longer allows group names to start with digits, so I have made this
293        change also in PCRE. It simplifies the code a bit.
294    
295    37. In extended mode, Perl ignores spaces before a + that indicates a
296        possessive quantifier. PCRE allowed a space before the quantifier, but not
297        before the possessive +. It now does.
298    
299    38. The use of \K (reset reported match start) within a repeated possessive
300        group such as (a\Kb)*+ was not working.
301    
302    40. Document that the same character tables must be used at compile time and
303        run time, and that the facility to pass tables to pcre_exec() and
304        pcre_dfa_exec() is for use only with saved/restored patterns.
305    
306    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
307        features for Builds with MSVC:
308    
309        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
310           builds). The .rc files can be used to set FileDescription and many other
311           attributes.
312    
313        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
314           This allows higher-level build scripts which want .pdb files to avoid
315           hard-coding the exact files needed."
316    
317    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
318        mean "start of word" and "end of word", respectively, as a transition aid.
319    
320    43. A minimizing repeat of a class containing codepoints greater than 255 in
321        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
322        compiled to use the heap for recursion.
323    
324    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
325        is configured.
326    
327    
328    Version 8.33 28-May-2013
329    ------------------------
330    
331    1.  Added 'U' to some constants that are compared to unsigned integers, to
332        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
333        variables that are added to signed variables, to ensure the result is
334        signed and can be negated.
335    
336    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
337        CMake config files.
338    
339    3.  Revise the creation of config.h.generic so that all boolean macros are
340        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
341        overriding via -D on the command line possible.
342    
343    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
344        to unsigned int is reported to make a quite noticeable speed difference in
345        a specific Windows environment. Testing on Linux did also appear to show
346        some benefit (and it is clearly not harmful). Also fixed the definition of
347        Xop which should be unsigned.
348    
349    5.  Related to (4), changing the definition of the intermediate variable cc
350        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
351        improvements.
352    
353    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
354        unnecessary spaces.
355    
356    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
357        and later.
358    
359    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
360    
361    9.  Optimizing fast_forward_start_bits in JIT.
362    
363    10. Adding support for callouts in JIT, and fixing some issues revealed
364        during this work. Namely:
365    
366        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
367    
368        (b) Minimum length was not checked before the matching is started.
369    
370    11. The value of capture_last that is passed to callouts was incorrect in some
371        cases when there was a capture on one path that was subsequently abandoned
372        after a backtrack. Also, the capture_last value is now reset after a
373        recursion, since all captures are also reset in this case.
374    
375    12. The interpreter no longer returns the "too many substrings" error in the
376        case when an overflowing capture is in a branch that is subsequently
377        abandoned after a backtrack.
378    
379    13. In the pathological case when an offset vector of size 2 is used, pcretest
380        now prints out the matched string after a yield of 0 or 1.
381    
382    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
383        Only supported by the JIT compiler at the moment.
384    
385    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
386    
387    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
388        offset of the starting point of the matching process, provided the offsets
389        vector is large enough.
390    
391    17. The \A escape now records a lookbehind value of 1, though its execution
392        does not actually inspect the previous character. This is to ensure that,
393        in partial multi-segment matching, at least one character from the old
394        segment is retained when a new segment is processed. Otherwise, if there
395        are no lookbehinds in the pattern, \A might match incorrectly at the start
396        of a new segment.
397    
398    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
399    
400    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
401        gives some modest performance improvement in 8-bit mode.
402    
403    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
404        be expressed in certain programming languages using Universal Character
405        Names.
406    
407    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
408        which points out that "non characters" are not "characters that may not
409        appear in Unicode strings" but rather "characters that are reserved for
410        internal use and have only local meaning".
411    
412    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
413        there was a conditional group that depended on an assertion, if the
414        assertion was false, the callout that immediately followed the alternation
415        in the condition was skipped when pcre_exec() was used for matching.
416    
417    23. Allow an explicit callout to be inserted before an assertion that is the
418        condition for a conditional group, for compatibility with automatic
419        callouts, which always insert a callout at this point.
420    
421    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
422        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
423    
424    25. (*PRUNE) is now supported by the JIT compiler.
425    
426    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
427    
428    27. Fix the case where there are two or more SKIPs with arguments that may be
429        ignored.
430    
431    28. (*SKIP) is now supported by the JIT compiler.
432    
433    29. (*THEN) is now supported by the JIT compiler.
434    
435    30. Update RunTest with additional test selector options.
436    
437    31. The way PCRE handles backtracking verbs has been changed in two ways.
438    
439        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
440        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
441        backtracking. In some cases this makes it more Perl-compatible, but Perl's
442        rather obscure rules do not always do the same thing.
443    
444        (2) Previously, backtracking verbs were confined within assertions. This is
445        no longer the case for positive assertions, except for (*ACCEPT). Again,
446        this sometimes improves Perl compatibility, and sometimes does not.
447    
448    32. A number of tests that were in test 2 because Perl did things differently
449        have been moved to test 1, because either Perl or PCRE has changed, and
450        these tests are now compatible.
451    
452    32. Backtracking control verbs are now handled in the same way in JIT and
453        interpreter.
454    
455    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
456        contained a forward subroutine reference caused a compile error.
457    
458    34. Auto-detect and optimize limited repetitions in JIT.
459    
460    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
461        blocking (*UTF) etc.
462    
463    36. In the interpreter, maximizing pattern repetitions for characters and
464        character types now use tail recursion, which reduces stack usage.
465    
466    37. The value of the max lookbehind was not correctly preserved if a compiled
467        and saved regex was reloaded on a host of different endianness.
468    
469    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
470        of the compiled pattern block, expand the flags field from 16 to 32 bits
471        because it was almost full.
472    
473    39. Try madvise first before posix_madvise.
474    
475    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
476        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
477        original change locked out all matches of empty strings. This has been
478        changed so that one match of an empty string per line is recognized.
479        Subsequent searches on the same line (for colouring or for --only-matching,
480        for example) do not recognize empty strings.
481    
482    41. Applied a user patch to fix a number of spelling mistakes in comments.
483    
484    42. Data lines longer than 65536 caused pcretest to crash.
485    
486    43. Clarified the data type for length and startoffset arguments for pcre_exec
487        and pcre_dfa_exec in the function-specific man pages, where they were
488        explicitly stated to be in bytes, never having been updated. I also added
489        some clarification to the pcreapi man page.
490    
491    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
492        a segmentation fault.
493    
494    
495    Version 8.32 30-November-2012
496    -----------------------------
497    
498    1.  Improved JIT compiler optimizations for first character search and single
499        character iterators.
500    
501    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
502        Patch by Daniel Richard G.
503    
504    3.  Single character iterator optimizations in the JIT compiler.
505    
506    4.  Improved JIT compiler optimizations for character ranges.
507    
508    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
509        Reported by Giuseppe D'Angelo.
510    
511    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
512        of a line, was being set incorrectly in cases where .* appeared inside
513        atomic brackets at the start of a pattern, or where there was a subsequent
514        *PRUNE or *SKIP.
515    
516    7.  Improved instruction cache flush for POWER/PowerPC.
517        Patch by Daniel Richard G.
518    
519    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
520        grep:
521    
522        (a) There is now no limit to the number of patterns to be matched.
523    
524        (b) An error is given if a pattern is too long.
525    
526        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
527            are now supported.
528    
529        (d) --exclude-from and --include-from (multiple use) have been added.
530    
531        (e) Exclusions and inclusions now apply to all files and directories, not
532            just to those obtained from scanning a directory recursively.
533    
534        (f) Multiple uses of -f and --file-list are now supported.
535    
536        (g) In a Windows environment, the default for -d has been changed from
537            "read" (the GNU grep default) to "skip", because otherwise the presence
538            of a directory in the file list provokes an error.
539    
540        (h) The documentation has been revised and clarified in places.
541    
542    9.  Improve the matching speed of capturing brackets.
543    
544    10. Changed the meaning of \X so that it now matches a Unicode extended
545        grapheme cluster.
546    
547    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
548        out POSIX threads when JIT support is configured.
549    
550    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
551    
552    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
553        structure could go wrong in environments where size_t is not the same size
554        as int.
555    
556    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
557        set.
558    
559    15. The EBCDIC support had decayed; later updates to the code had included
560        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
561        general tidy up of EBCDIC-related issues, and the documentation was also
562        not quite right. There is now a test that can be run on ASCII systems to
563        check some of the EBCDIC-related things (but is it not a full test).
564    
565    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
566        in a small tidy to the code.
567    
568    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
569    
570    18. If the --only-matching (-o) option in pcregrep is specified multiple
571        times, each one causes appropriate output. For example, -o1 -o2 outputs the
572        substrings matched by the 1st and 2nd capturing parentheses. A separating
573        string can be specified by --om-separator (default empty).
574    
575    19. Improving the first n character searches.
576    
577    20. Turn case lists for horizontal and vertical white space into macros so that
578        they are defined only once.
579    
580    21. This set of changes together give more compatible Unicode case-folding
581        behaviour for characters that have more than one other case when UCP
582        support is available.
583    
584        (a) The Unicode property table now has offsets into a new table of sets of
585            three or more characters that are case-equivalent. The MultiStage2.py
586            script that generates these tables (the pcre_ucd.c file) now scans
587            CaseFolding.txt instead of UnicodeData.txt for character case
588            information.
589    
590        (b) The code for adding characters or ranges of characters to a character
591            class has been abstracted into a generalized function that also handles
592            case-independence. In UTF-mode with UCP support, this uses the new data
593            to handle characters with more than one other case.
594    
595        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
596            whose other case is greater than 256 are now correctly matched
597            caselessly. Previously, the high codepoint matched the low one, but not
598            vice versa.
599    
600        (d) The processing of \h, \H, \v, and \ in character classes now makes use
601            of the new class addition function, using character lists defined as
602            macros alongside the case definitions of 20 above.
603    
604        (e) Caseless back references now work with characters that have more than
605            one other case.
606    
607        (f) General caseless matching of characters with more than one other case
608            is supported.
609    
610    22. Unicode character properties were updated from Unicode 6.2.0
611    
612    23. Improved CMake support under Windows. Patch by Daniel Richard G.
613    
614    24. Add support for 32-bit character strings, and UTF-32
615    
616    25. Major JIT compiler update (code refactoring and bugfixing).
617        Experimental Sparc 32 support is added.
618    
619    26. Applied a modified version of Daniel Richard G's patch to create
620        pcre.h.generic and config.h.generic by "make" instead of in the
621        PrepareRelease script.
622    
623    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
624        pcre_compile.c when checking for a zero character.
625    
626    28. Introducing a native interface for JIT. Through this interface, the compiled
627        machine code can be directly executed. The purpose of this interface is to
628        provide fast pattern matching, so several sanity checks are not performed.
629        However, feature tests are still performed. The new interface provides
630        1.4x speedup compared to the old one.
631    
632    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
633        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
634        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
635    
636    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
637        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
638        the "old" RFC 2279). Instead, it ended up passing a negative length to
639        pcre_exec().
640    
641    31. Add support for GCC's visibility feature to hide internal functions.
642    
643    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
644        "unknown -C option" after outputting 0 or 1.
645    
646    33. There is now support for generating a code coverage report for the test
647        suite in environments where gcc is the compiler and lcov is installed. This
648        is mainly for the benefit of the developers.
649    
650    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
651        unaddressable using valgrind annotations, allowing valgrind to detect
652        invalid memory accesses. This is mainly for the benefit of the developers.
653    
654    25. (*UTF) can now be used to start a pattern in any of the three libraries.
655    
656    26. Give configure error if --enable-cpp but no C++ compiler found.
657    
658    
659    Version 8.31 06-July-2012
660    -------------------------
661    
662    1.  Fixing a wrong JIT test case and some compiler warnings.
663    
664    2.  Removed a bashism from the RunTest script.
665    
666    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
667        to unsigned type, result still unsigned" that was given by an MS compiler
668        on encountering the code "-sizeof(xxx)".
669    
670    4.  Partial matching support is added to the JIT compiler.
671    
672    5.  Fixed several bugs concerned with partial matching of items that consist
673        of more than one character:
674    
675        (a) /^(..)\1/ did not partially match "aba" because checking references was
676            done on an "all or nothing" basis. This also applied to repeated
677            references.
678    
679        (b) \R did not give a hard partial match if \r was found at the end of the
680            subject.
681    
682        (c) \X did not give a hard partial match after matching one or more
683            characters at the end of the subject.
684    
685        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
686            a partial match for the string "\r".
687    
688        (e) When newline was set to CRLF, the metacharacter "." did not recognize
689            a partial match for a CR character at the end of the subject string.
690    
691    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
692        running pcretest, the text "(JIT)" added to the output whenever JIT is
693        actually used to run the match.
694    
695    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
696        or /S+[+] with a digit between 1 and 7.
697    
698    8.  OP_NOT now supports any UTF character not just single-byte ones.
699    
700    9.  (*MARK) control verb is now supported by the JIT compiler.
701    
702    10. The command "./RunTest list" lists the available tests without actually
703        running any of them. (Because I keep forgetting what they all are.)
704    
705    11. Add PCRE_INFO_MAXLOOKBEHIND.
706    
707    12. Applied a (slightly modified) user-supplied patch that improves performance
708        when the heap is used for recursion (compiled with --disable-stack-for-
709        recursion). Instead of malloc and free for each heap frame each time a
710        logical recursion happens, frames are retained on a chain and re-used where
711        possible. This sometimes gives as much as 30% improvement.
712    
713    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
714        call.
715    
716    14. As documented, (*COMMIT) is now confined to within a positive assertion.
717    
718    15. It is now possible to link pcretest with libedit as an alternative to
719        libreadline.
720    
721    16. (*COMMIT) control verb is now supported by the JIT compiler.
722    
723    17. The Unicode data tables have been updated to Unicode 6.1.0.
724    
725    18. Added --file-list option to pcregrep.
726    
727    19. Added binary file support to pcregrep, including the -a, --binary-files,
728        -I, and --text options.
729    
730    20. The madvise function is renamed for posix_madvise for QNX compatibility
731        reasons. Fixed by Giuseppe D'Angelo.
732    
733    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
734    
735    22. Changed the option for creating symbolic links for 16-bit man pages from
736        -s to -sf so that re-installing does not cause issues.
737    
738    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
739    
740    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
741        matches in certain environments (the workspace was not being correctly
742        retained). Also added to pcre_dfa_exec() a simple plausibility check on
743        some of the workspace data at the beginning of a restart.
744    
745    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
746        was not doing so when it should - probably a typo introduced by SVN 528
747        (change 8.10/14).
748    
749    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
750        \w+ when the character tables indicated that \x{c4} was a word character.
751        There were several related cases, all because the tests for doing a table
752        lookup were testing for characters less than 127 instead of 255.
753    
754    27. If a pattern contains capturing parentheses that are not used in a match,
755        their slots in the ovector are set to -1. For those that are higher than
756        any matched groups, this happens at the end of processing. In the case when
757        there were back references that the ovector was too small to contain
758        (causing temporary malloc'd memory to be used during matching), and the
759        highest capturing number was not used, memory off the end of the ovector
760        was incorrectly being set to -1. (It was using the size of the temporary
761        memory instead of the true size.)
762    
763    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
764        ovector size, it uses memory at the end of the block that it has got.
765    
766    29. Check for an overlong MARK name and give an error at compile time. The
767        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
768    
769    30. JIT compiler update.
770    
771    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
772        Rill for the patch.
773    
774    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
775    
776    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
777    
778    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
779        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
780        was enabled.
781    
782    35. Improve JIT code generation for greedy plus quantifier.
783    
784    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
785        1 to "aa" instead of to an empty string. The bug affected repeated groups
786        that could potentially match an empty string.
787    
788    37. Optimizing single character iterators in JIT.
789    
790    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
791        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
792        codepoints that are too big for the mode are faulted, and in a UTF mode,
793        disallowed codepoints are also faulted.
794    
795    39. If PCRE was compiled with UTF support, in three places in the DFA
796        matcher there was code that should only have been obeyed in UTF mode, but
797        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
798        processing when bytes with values greater than 127 were present. In 16-bit
799        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
800        both cases the values are those that cannot be the first data item in a UTF
801        character. The three items that might have provoked this were recursions,
802        possessively repeated groups, and atomic groups.
803    
804    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
805        and pcregrep, because some OS require shared objects to be explicitly
806        passed to ld, causing the link step to fail if they are not.
807    
808    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
809        mode, patterns that started with \h* or \R* might be incorrectly matched.
810    
811    
812    Version 8.30 04-February-2012
813    -----------------------------
814    
815    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
816        name is defined in ctype.h.
817    
818    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
819        only in quite long subpatterns.
820    
821    3.  Removed the function pcre_info(), which has been obsolete and deprecated
822        since it was replaced by pcre_fullinfo() in February 2000.
823    
824    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
825        match a (*MARK), and the match failed at the start of the subject, a
826        reference to memory before the start of the subject could occur. This bug
827        was introduced by fix 17 of release 8.21.
828    
829    5.  A reference to an unset group with zero minimum repetition was giving
830        totally wrong answers (in non-JavaScript-compatibility mode). For example,
831        /(another)?(\1?)test/ matched against "hello world test". This bug was
832        introduced in release 8.13.
833    
834    6.  Add support for 16-bit character strings (a large amount of work involving
835        many changes and refactorings).
836    
837    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
838        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
839        from a file.
840    
841    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
842        rounding is not applied in this particular case).
843    
844    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
845        if they appear, or are escaped, in patterns.
846    
847    10. Get rid of a number of -Wunused-but-set-variable warnings.
848    
849    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
850        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
851        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
852        also returns the mark "x". This bug applied to capturing parentheses,
853        non-capturing parentheses, and atomic parentheses. It also applied to some
854        assertions.
855    
856    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
857        information out of configure.ac instead of relying on pcre.h.generic, which
858        is not stored in the repository.
859    
860    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
861        -lreadline.
862    
863    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
864    
865    15. Applied Graycode's patch to put the top-level frame on the stack rather
866        than the heap when not using the stack for recursion. This gives a
867        performance improvement in many cases when recursion is not deep.
868    
869    16. Experimental code added to "pcretest -C" to output the stack frame size.
870    
871    
872    Version 8.21 12-Dec-2011
873    ------------------------
874    
875    1.  Updating the JIT compiler.
876    
877    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
878        are added as well.
879    
880    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
881        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
882        calling _pcre_jit_exec. Some extra comments are added.
883    
884    4.  (*MARK) settings inside atomic groups that do not contain any capturing
885        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
886        was introduced by change 18 for 8.20.
887    
888    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
889        ECMA-262 standard.
890    
891    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
892        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
893        This bug was probably introduced by change 9 of 8.13.
894    
895    7.  While fixing 6 above, I noticed that a number of other items were being
896        incorrectly rejected as "not fixed length". This arose partly because newer
897        opcodes had not been added to the fixed-length checking code. I have (a)
898        corrected the bug and added tests for these items, and (b) arranged for an
899        error to occur if an unknown opcode is encountered while checking for fixed
900        length instead of just assuming "not fixed length". The items that were
901        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
902        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
903        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
904    
905    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
906        being incorrectly compiled and would have given unpredicatble results.
907    
908    9.  A possessively repeated subpattern with minimum repeat count greater than
909        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
910        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
911        the first (A) could occur when it should not.
912    
913    10. Add a cast and remove a redundant test from the code.
914    
915    11. JIT should use pcre_malloc/pcre_free for allocation.
916    
917    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
918        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
919        is anything other than /usr, -L is still shown).
920    
921    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
922    
923    14. Perl does not support \N without a following name in a [] class; PCRE now
924        also gives an error.
925    
926    15. If a forward reference was repeated with an upper limit of around 2000,
927        it caused the error "internal error: overran compiling workspace". The
928        maximum number of forward references (including repeats) was limited by the
929        internal workspace, and dependent on the LINK_SIZE. The code has been
930        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
931        the default depends on LINK_SIZE. There is a new upper limit (for safety)
932        of around 200,000 forward references. While doing this, I also speeded up
933        the filling in of repeated forward references.
934    
935    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
936        incorrectly expecting the subject to contain another "a" after the start.
937    
938    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
939        in the match, the SKIP should be ignored. This was not happening; instead
940        the SKIP was being treated as NOMATCH. For patterns such as
941        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
942        tested.
943    
944    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
945        now much more compatible with Perl, in particular in cases where the result
946        is a non-match for a non-anchored pattern. For example, if
947        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
948        "m", where previously it did not return a name. A side effect of this
949        change is that for partial matches, the last encountered mark name is
950        returned, as for non matches. A number of tests that were previously not
951        Perl-compatible have been moved into the Perl-compatible test files. The
952        refactoring has had the pleasing side effect of removing one argument from
953        the match() function, thus reducing its stack requirements.
954    
955    19. If the /S+ option was used in pcretest to study a pattern using JIT,
956        subsequent uses of /S (without +) incorrectly behaved like /S+.
957    
958    21. Retrieve executable code size support for the JIT compiler and fixing
959        some warnings.
960    
961    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
962        not work when the shorter character appeared right at the end of the
963        subject string.
964    
965    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
966        systems.
967    
968    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
969        output it when the /M option is used in pcretest.
970    
971    25. The CheckMan script was not being included in the distribution. Also, added
972        an explicit "perl" to run Perl scripts from the PrepareRelease script
973        because this is reportedly needed in Windows.
974    
975    26. If study data was being save in a file and studying had not found a set of
976        "starts with" bytes for the pattern, the data written to the file (though
977        never used) was taken from uninitialized memory and so caused valgrind to
978        complain.
979    
980    27. Updated RunTest.bat as provided by Sheri Pierce.
981    
982    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
983    
984    29. Computation of memory usage for the table of capturing group names was
985        giving an unnecessarily large value.
986    
987    
988    Version 8.20 21-Oct-2011
989    ------------------------
990    
991    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
992        a POSIX class. After further experiments with Perl, which convinced me that
993        Perl has bugs and confusions, a closing square bracket is no longer allowed
994        in a POSIX name. This bug also affected patterns with classes that started
995        with full stops.
996    
997    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
998        captured substring, but while checking the failing first alternative,
999        substring 1 is temporarily captured. If the output vector supplied to
1000        pcre_exec() was not big enough for this capture, the yield of the function
1001        was still zero ("insufficient space for captured substrings"). This cannot
1002        be totally fixed without adding another stack variable, which seems a lot
1003        of expense for a edge case. However, I have improved the situation in cases
1004        such as /(a)(b)x|abc/ matched against "abc", where the return code
1005        indicates that fewer than the maximum number of slots in the ovector have
1006        been set.
1007    
1008    3.  Related to (2) above: when there are more back references in a pattern than
1009        slots in the output vector, pcre_exec() uses temporary memory during
1010        matching, and copies in the captures as far as possible afterwards. It was
1011        using the entire output vector, but this conflicts with the specification
1012        that only 2/3 is used for passing back captured substrings. Now it uses
1013        only the first 2/3, for compatibility. This is, of course, another edge
1014        case.
1015    
1016    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1017        main code base, and can be used by building with --enable-jit. When this is
1018        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1019        runtime --no-jit option is given.
1020    
1021    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1022        ovector, the return from the function was zero, implying that there were
1023        other matches that did not fit. The correct "exactly full" value is now
1024        returned.
1025    
1026    6.  If a subpattern that was called recursively or as a subroutine contained
1027        (*PRUNE) or any other control that caused it to give a non-standard return,
1028        invalid errors such as "Error -26 (nested recursion at the same subject
1029        position)" or even infinite loops could occur.
1030    
1031    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1032        computing the minimum length on reaching *ACCEPT, and so ended up with the
1033        wrong value of 1 rather than 0. Further investigation indicates that
1034        computing a minimum subject length in the presence of *ACCEPT is difficult
1035        (think back references, subroutine calls), and so I have changed the code
1036        so that no minimum is registered for a pattern that contains *ACCEPT.
1037    
1038    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1039        it was not handled as intended. [But see 16 below.]
1040    
1041    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1042        Sheri Pierce.
1043    
1044    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1045        the first byte in a match must be "a".
1046    
1047    11. Change 17 for 8.13 increased the recursion depth for patterns like
1048        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1049        pattern contains any instances of (*THEN). If it does not, the old
1050        optimizations are restored. It would be nice to do this on a per-group
1051        basis, but at the moment that is not feasible.
1052    
1053    12. In some environments, the output of pcretest -C is CRLF terminated. This
1054        broke RunTest's code that checks for the link size. A single white space
1055        character after the value is now allowed for.
1056    
1057    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1058        For "fr", it uses the Windows-specific input and output files.
1059    
1060    14. If (*THEN) appeared in a group that was called recursively or as a
1061        subroutine, it did not work as intended. [But see next item.]
1062    
1063    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1064        pattern fragments (but not containing any | characters). If A and B are
1065        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1066        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1067        D. In other words, Perl considers parentheses that do not contain any |
1068        characters to be part of a surrounding alternative, whereas PCRE was
1069        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1070        differently. PCRE now behaves in the same way as Perl, except in the case
1071        of subroutine/recursion calls such as (?1) which have in any case always
1072        been different (but PCRE had them first :-).
1073    
1074    16. Related to 15 above: Perl does not treat the | in a conditional group as
1075        creating alternatives. Such a group is treated in the same way as an
1076        ordinary group without any | characters when processing (*THEN). PCRE has
1077        been changed to match Perl's behaviour.
1078    
1079    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1080        RunGrepTest script failed.
1081    
1082    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1083        inevitable for groups that contain captures, but it can lead to a lot of
1084        stack use in large patterns. The old behaviour has been restored for atomic
1085        groups that do not contain any capturing parentheses.
1086    
1087    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1088        suppress the check for a minimum subject length at run time. (If it was
1089        given to pcre_exec() or pcre_dfa_exec() it did work.)
1090    
1091    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1092        fail to work when decoding hex characters in data strings in EBCDIC
1093        environments.
1094    
1095    21. It appears that in at least one Mac OS environment, the isxdigit() function
1096        is implemented as a macro that evaluates to its argument more than once,
1097        contravening the C 90 Standard (I haven't checked a later standard). There
1098        was an instance in pcretest which caused it to go wrong when processing
1099        \x{...} escapes in subject strings. The has been rewritten to avoid using
1100        things like p++ in the argument of isxdigit().
1101    
1102    
1103  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
# Line 107  Version 8.13 16-Aug-2011 Line 1197  Version 8.13 16-Aug-2011
1197      tail recursion to cut down on stack usage. Unfortunately, now that there is      tail recursion to cut down on stack usage. Unfortunately, now that there is
1198      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
1199      no longer possible because the return has to be checked for (*THEN). These      no longer possible because the return has to be checked for (*THEN). These
1200      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
1201    
1202  18. If a pattern containing \R was studied, it was assumed that \R always  18. If a pattern containing \R was studied, it was assumed that \R always
1203      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
# Line 909  Version 7.9 11-Apr-09 Line 1999  Version 7.9 11-Apr-09
1999  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
2000      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
2001      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2002      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2003        8.33.]
2004    
2005  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
2006      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 1152  Version 7.7 07-May-08 Line 2243  Version 7.7 07-May-08
2243      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2244      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2245      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2246      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2247      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2248      was subsequently set up correctly.)      was subsequently set up correctly.)
2249    

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