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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 02-Aug-2011  Version 8.37 xx-xxx-2015
5    ------------------------
6    
7    1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
8        for those parentheses to be closed with whatever has been captured so far.
9        However, it was failing to mark any other groups between the hightest
10        capture so far and the currrent group as "unset". Thus, the ovector for
11        those groups contained whatever was previously there. An example is the
12        pattern /(x)|((*ACCEPT))/ when matched against "abcd".
13    
14    2.  If an assertion condition was quantified with a minimum of zero (an odd
15        thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
16    
17    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
18        unrecognized modifier, a crash could occur.
19    
20    4.  An attempt to do global matching in pcretest with a zero-length ovector
21        caused a crash.
22    
23    5.  Fixed a memory leak during matching that could occur for a subpattern
24        subroutine call (recursive or otherwise) if the number of captured groups
25        that had to be saved was greater than ten.
26    
27    6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
28        string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
29        UTF with NO_UTF_CHECK is documented as having an undefined outcome.
30    
31    7.  A UTF pattern containing a "not" match of a non-ASCII character and a
32        subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
33    
34    8. When a pattern is compiled, it remembers the highest back reference so that
35       when matching, if the ovector is too small, extra memory can be obtained to
36       use instead. A conditional subpattern whose condition is a check on a
37       capture having happened, such as, for example in the pattern
38       /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
39       setting the highest backreference number. This mattered only if pcre_exec()
40       was called with an ovector that was too small to hold the capture, and there
41       was no other kind of back reference (a situation which is probably quite
42       rare). The effect of the bug was that the condition was always treated as
43       FALSE when the capture could not be consulted, leading to a incorrect
44       behaviour by pcre2_match(). This bug has been fixed.
45    
46    
47    Version 8.36 26-September-2014
48    ------------------------------
49    
50    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
51        -Wmissing-field-initializers and -Wunused-parameter.
52    
53    2.  The tests for quantifiers being too big (greater than 65535) were being
54        applied after reading the number, and stupidly assuming that integer
55        overflow would give a negative number. The tests are now applied as the
56        numbers are read.
57    
58    3.  Tidy code in pcre_exec.c where two branches that used to be different are
59        now the same.
60    
61    4.  The JIT compiler did not generate match limit checks for certain
62        bracketed expressions with quantifiers. This may lead to exponential
63        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
64        issue should be resolved now.
65    
66    5.  Fixed an issue, which occures when nested alternatives are optimized
67        with table jumps.
68    
69    6.  Inserted two casts and changed some ints to size_t in the light of some
70        reported 64-bit compiler warnings (Bugzilla 1477).
71    
72    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
73        an empty string, which sometimes were behaving incorrectly in the
74        interpreter (though correctly in the JIT matcher). This pcretest input is
75        an example:
76    
77          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
78          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
79    
80        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
81        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
82        for an empty string was breaking the inner loop and carrying on at a lower
83        level, when possessive repeated groups should always return to a higher
84        level as they have no backtrack points in them. The empty string test now
85        occurs at the outer level.
86    
87    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
88        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
89    
90    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
91        doesn't).
92    
93    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
94        to hold a pattern to be incorrectly computed (too small) when there were
95        named back references to duplicated names. This could cause "internal
96        error: code overflow" or "double free or corruption" or other memory
97        handling errors.
98    
99    11. When named subpatterns had the same prefixes, back references could be
100        confused. For example, in this pattern:
101    
102          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
103    
104        the reference to 'Name' was incorrectly treated as a reference to a
105        duplicate name.
106    
107    12. A pattern such as /^s?c/mi8 where the optional character has more than
108        one "other case" was incorrectly compiled such that it would only try to
109        match starting at "c".
110    
111    13. When a pattern starting with \s was studied, VT was not included in the
112        list of possible starting characters; this should have been part of the
113        8.34/18 patch.
114    
115    14. If a character class started [\Qx]... where x is any character, the class
116        was incorrectly terminated at the ].
117    
118    15. If a pattern that started with a caseless match for a character with more
119        than one "other case" was studied, PCRE did not set up the starting code
120        unit bit map for the list of possible characters. Now it does. This is an
121        optimization improvement, not a bug fix.
122    
123    16. The Unicode data tables have been updated to Unicode 7.0.0.
124    
125    17. Fixed a number of memory leaks in pcregrep.
126    
127    18. Avoid a compiler warning (from some compilers) for a function call with
128        a cast that removes "const" from an lvalue by using an intermediate
129        variable (to which the compiler does not object).
130    
131    19. Incorrect code was compiled if a group that contained an internal recursive
132        back reference was optional (had quantifier with a minimum of zero). This
133        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
134        caused segmentation faults because of stack overflows at compile time.
135    
136    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
137        group that is quantified with an indefinite repeat, caused a compile-time
138        loop which used up all the system stack and provoked a segmentation fault.
139        This was not the same bug as 19 above.
140    
141    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
142        Patch by Mike Frysinger.
143    
144    
145    Version 8.35 04-April-2014
146    --------------------------
147    
148    1.  A new flag is set, when property checks are present in an XCLASS.
149        When this flag is not set, PCRE can perform certain optimizations
150        such as studying these XCLASS-es.
151    
152    2.  The auto-possessification of character sets were improved: a normal
153        and an extended character set can be compared now. Furthermore
154        the JIT compiler optimizes more character set checks.
155    
156    3.  Got rid of some compiler warnings for potentially uninitialized variables
157        that show up only when compiled with -O2.
158    
159    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
160        of a match later then the end of the match. The pcretest program was not
161        handling the case sensibly - it was outputting from the start to the next
162        binary zero. It now reports this situation in a message, and outputs the
163        text from the end to the start.
164    
165    5.  Fast forward search is improved in JIT. Instead of the first three
166        characters, any three characters with fixed position can be searched.
167        Search order: first, last, middle.
168    
169    6.  Improve character range checks in JIT. Characters are read by an inprecise
170        function now, which returns with an unknown value if the character code is
171        above a certain threshold (e.g: 256). The only limitation is that the value
172        must be bigger than the threshold as well. This function is useful when
173        the characters above the threshold are handled in the same way.
174    
175    7.  The macros whose names start with RAWUCHAR are placeholders for a future
176        mode in which only the bottom 21 bits of 32-bit data items are used. To
177        make this more memorable for those maintaining the code, the names have
178        been changed to start with UCHAR21, and an extensive comment has been added
179        to their definition.
180    
181    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
182        to the export list in Makefile.am (they were accidentally omitted from the
183        8.34 tarball).
184    
185    9.  The informational output from pcretest used the phrase "starting byte set"
186        which is inappropriate for the 16-bit and 32-bit libraries. As the output
187        for "first char" and "need char" really means "non-UTF-char", I've changed
188        "byte" to "char", and slightly reworded the output. The documentation about
189        these values has also been (I hope) clarified.
190    
191    10. Another JIT related optimization: use table jumps for selecting the correct
192        backtracking path, when more than four alternatives are present inside a
193        bracket.
194    
195    11. Empty match is not possible, when the minimum length is greater than zero,
196        and there is no \K in the pattern. JIT should avoid empty match checks in
197        such cases.
198    
199    12. In a caseless character class with UCP support, when a character with more
200        than one alternative case was not the first character of a range, not all
201        the alternative cases were added to the class. For example, s and \x{17f}
202        are both alternative cases for S: the class [RST] was handled correctly,
203        but [R-T] was not.
204    
205    13. The configure.ac file always checked for pthread support when JIT was
206        enabled. This is not used in Windows, so I have put this test inside a
207        check for the presence of windows.h (which was already tested for).
208    
209    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
210        The algorithm provides a way to skip certain starting offsets, and usually
211        faster than linear prefix searches.
212    
213    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
214        as for 'fr_FR' and 'french'. For some reason, however, it then used the
215        Windows-specific input and output files, which have 'french' screwed in.
216        So this could never have worked. One of the problems with locales is that
217        they aren't always the same. I have now updated RunTest so that it checks
218        the output of the locale test (test 3) against three different output
219        files, and it allows the test to pass if any one of them matches. With luck
220        this should make the test pass on some versions of Solaris where it was
221        failing. Because of the uncertainty, the script did not used to stop if
222        test 3 failed; it now does. If further versions of a French locale ever
223        come to light, they can now easily be added.
224    
225    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
226        there was a message during ./configure, but it did not stop. This now
227        provokes an error. The invalid example in README has been corrected.
228        If a value less than the minimum is given, the minimum value has always
229        been used, but now a warning is given.
230    
231    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
232        was a bug in the test system, which is now fixed. Also, the list of various
233        configurations that are tested for each release did not have one with both
234        16/32 bits and --enable-bar-anycrlf. It now does.
235    
236    18. pcretest was missing "-C bsr" for displaying the \R default setting.
237    
238    19. Little endian PowerPC systems are supported now by the JIT compiler.
239    
240    20. The fast forward newline mechanism could enter to an infinite loop on
241        certain invalid UTF-8 input. Although we don't support these cases
242        this issue can be fixed by a performance optimization.
243    
244    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
245        not take account if existing stack usage. There is now a new global
246        variable called pcre_stack_guard that can be set to point to an external
247        function to check stack availability. It is called at the start of
248        processing every parenthesized group.
249    
250    22. A typo in the code meant that in ungreedy mode the max/min qualifier
251        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
252        not match "ab".
253    
254    23. When UTF was disabled, the JIT program reported some incorrect compile
255        errors. These messages are silenced now.
256    
257    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
258        compiler.
259    
260    25. Change all the temporary files used in RunGrepTest to be different to those
261        used by RunTest so that the tests can be run simultaneously, for example by
262        "make -j check".
263    
264    
265    Version 8.34 15-December-2013
266    -----------------------------
267    
268    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
269        executable memory. Patch inspired by Carsten Klein.
270    
271    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
272        this macro is never tested and has no effect, because the work to support
273        coverage involves only compiling and linking options and special targets in
274        the Makefile. The comment in config.h implied that defining the macro would
275        enable coverage support, which is totally false. There was also support for
276        setting this macro in the CMake files (my fault, I just copied it from
277        configure). SUPPORT_GCOV has now been removed.
278    
279    3.  Make a small performance improvement in strlen16() and strlen32() in
280        pcretest.
281    
282    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
283        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
284        these cases). There was also one in pcretest.c.
285    
286    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
287    
288    6.  In UTF mode, the code for checking whether a group could match an empty
289        string (which is used for indefinitely repeated groups to allow for
290        breaking an infinite loop) was broken when the group contained a repeated
291        negated single-character class with a character that occupied more than one
292        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
293        UTF-8 mode). The effect was undefined: the group might or might not be
294        deemed as matching an empty string, or the program might have crashed.
295    
296    7.  The code for checking whether a group could match an empty string was not
297        recognizing that \h, \H, \v, \V, and \R must match a character.
298    
299    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
300        an empty string. If it can, pcretest shows this in its information output.
301    
302    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
303        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
304        matched by pcre_exec() without using JIT:
305    
306        (a) If the rest of the pattern did not match after a maximal run of
307            grapheme clusters, the code for backing up to try with fewer of them
308            did not always back up over a full grapheme when characters that do not
309            have the modifier quality were involved, e.g. Hangul syllables.
310    
311        (b) If the match point in a subject started with modifier character, and
312            there was no match, the code could incorrectly back up beyond the match
313            point, and potentially beyond the first character in the subject,
314            leading to a segfault or an incorrect match result.
315    
316    10. A conditional group with an assertion condition could lead to PCRE
317        recording an incorrect first data item for a match if no other first data
318        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
319        first data item, and therefore matched "ca" after "c" instead of at the
320        start.
321    
322    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
323        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
324    
325    12. The source of pcregrep now includes z/OS-specific code so that it can be
326        compiled for z/OS as part of the special z/OS distribution.
327    
328    13. Added the -T and -TM options to pcretest.
329    
330    14. The code in pcre_compile.c for creating the table of named capturing groups
331        has been refactored. Instead of creating the table dynamically during the
332        actual compiling pass, the information is remembered during the pre-compile
333        pass (on the stack unless there are more than 20 named groups, in which
334        case malloc() is used) and the whole table is created before the actual
335        compile happens. This has simplified the code (it is now nearly 150 lines
336        shorter) and prepared the way for better handling of references to groups
337        with duplicate names.
338    
339    15. A back reference to a named subpattern when there is more than one of the
340        same name now checks them in the order in which they appear in the pattern.
341        The first one that is set is used for the reference. Previously only the
342        first one was inspected. This change makes PCRE more compatible with Perl.
343    
344    16. Unicode character properties were updated from Unicode 6.3.0.
345    
346    17. The compile-time code for auto-possessification has been refactored, based
347        on a patch by Zoltan Herczeg. It now happens after instead of during
348        compilation. The code is cleaner, and more cases are handled. The option
349        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
350        options in pcretest are provided to set it. It can also be set by
351        (*NO_AUTO_POSSESS) at the start of a pattern.
352    
353    18. The character VT has been added to the default ("C" locale) set of
354        characters that match \s and are generally treated as white space,
355        following this same change in Perl 5.18. There is now no difference between
356        "Perl space" and "POSIX space". Whether VT is treated as white space in
357        other locales depends on the locale.
358    
359    19. The code for checking named groups as conditions, either for being set or
360        for being recursed, has been refactored (this is related to 14 and 15
361        above). Processing unduplicated named groups should now be as fast at
362        numerical groups, and processing duplicated groups should be faster than
363        before.
364    
365    20. Two patches to the CMake build system, by Alexander Barkov:
366    
367          (1) Replace the "source" command by "." in CMakeLists.txt because
368              "source" is a bash-ism.
369    
370          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
371              without these the CMake build does not work on Solaris.
372    
373    21. Perl has changed its handling of \8 and \9. If there is no previously
374        encountered capturing group of those numbers, they are treated as the
375        literal characters 8 and 9 instead of a binary zero followed by the
376        literals. PCRE now does the same.
377    
378    22. Following Perl, added \o{} to specify codepoints in octal, making it
379        possible to specify values greater than 0777 and also making them
380        unambiguous.
381    
382    23. Perl now gives an error for missing closing braces after \x{... instead of
383        treating the string as literal. PCRE now does the same.
384    
385    24. RunTest used to grumble if an inappropriate test was selected explicitly,
386        but just skip it when running all tests. This make it awkward to run ranges
387        of tests when one of them was inappropriate. Now it just skips any
388        inappropriate tests, as it always did when running all tests.
389    
390    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
391        character types such as \d or \w, too many callouts were inserted, and the
392        data that they returned was rubbish.
393    
394    26. In UCP mode, \s was not matching two of the characters that Perl matches,
395        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
396        were matched by \h. The code has now been refactored so that the lists of
397        the horizontal and vertical whitespace characters used for \h and \v (which
398        are defined only in one place) are now also used for \s.
399    
400    27. Add JIT support for the 64 bit TileGX architecture.
401        Patch by Jiong Wang (Tilera Corporation).
402    
403    28. Possessive quantifiers for classes (both explicit and automatically
404        generated) now use special opcodes instead of wrapping in ONCE brackets.
405    
406    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
407        (because it's meaningless), this was not happening when PCRE_CASELESS was
408        set. Not wrong, but inefficient.
409    
410    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
411        properties for \w, \d, etc) is present in a test regex. Otherwise if the
412        test contains no characters greater than 255, Perl doesn't realise it
413        should be using Unicode semantics.
414    
415    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
416        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
417        does in Unicode mode.
418    
419    32. Added the "forbid" facility to pcretest so that putting tests into the
420        wrong test files can sometimes be quickly detected.
421    
422    33. There is now a limit (default 250) on the depth of nesting of parentheses.
423        This limit is imposed to control the amount of system stack used at compile
424        time. It can be changed at build time by --with-parens-nest-limit=xxx or
425        the equivalent in CMake.
426    
427    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
428        errors. Perl warns for these when in warning mode, but PCRE has no facility
429        for giving warnings.
430    
431    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
432        However, this was not working for (?!) because it is optimized to (*FAIL),
433        for which PCRE does not allow quantifiers. The optimization is now disabled
434        when a quantifier follows (?!). I can't see any use for this, but it makes
435        things uniform.
436    
437    36. Perl no longer allows group names to start with digits, so I have made this
438        change also in PCRE. It simplifies the code a bit.
439    
440    37. In extended mode, Perl ignores spaces before a + that indicates a
441        possessive quantifier. PCRE allowed a space before the quantifier, but not
442        before the possessive +. It now does.
443    
444    38. The use of \K (reset reported match start) within a repeated possessive
445        group such as (a\Kb)*+ was not working.
446    
447    40. Document that the same character tables must be used at compile time and
448        run time, and that the facility to pass tables to pcre_exec() and
449        pcre_dfa_exec() is for use only with saved/restored patterns.
450    
451    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
452        features for Builds with MSVC:
453    
454        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
455           builds). The .rc files can be used to set FileDescription and many other
456           attributes.
457    
458        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
459           This allows higher-level build scripts which want .pdb files to avoid
460           hard-coding the exact files needed."
461    
462    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
463        mean "start of word" and "end of word", respectively, as a transition aid.
464    
465    43. A minimizing repeat of a class containing codepoints greater than 255 in
466        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
467        compiled to use the heap for recursion.
468    
469    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
470        is configured.
471    
472    
473    Version 8.33 28-May-2013
474    ------------------------
475    
476    1.  Added 'U' to some constants that are compared to unsigned integers, to
477        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
478        variables that are added to signed variables, to ensure the result is
479        signed and can be negated.
480    
481    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
482        CMake config files.
483    
484    3.  Revise the creation of config.h.generic so that all boolean macros are
485        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
486        overriding via -D on the command line possible.
487    
488    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
489        to unsigned int is reported to make a quite noticeable speed difference in
490        a specific Windows environment. Testing on Linux did also appear to show
491        some benefit (and it is clearly not harmful). Also fixed the definition of
492        Xop which should be unsigned.
493    
494    5.  Related to (4), changing the definition of the intermediate variable cc
495        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
496        improvements.
497    
498    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
499        unnecessary spaces.
500    
501    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
502        and later.
503    
504    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
505    
506    9.  Optimizing fast_forward_start_bits in JIT.
507    
508    10. Adding support for callouts in JIT, and fixing some issues revealed
509        during this work. Namely:
510    
511        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
512    
513        (b) Minimum length was not checked before the matching is started.
514    
515    11. The value of capture_last that is passed to callouts was incorrect in some
516        cases when there was a capture on one path that was subsequently abandoned
517        after a backtrack. Also, the capture_last value is now reset after a
518        recursion, since all captures are also reset in this case.
519    
520    12. The interpreter no longer returns the "too many substrings" error in the
521        case when an overflowing capture is in a branch that is subsequently
522        abandoned after a backtrack.
523    
524    13. In the pathological case when an offset vector of size 2 is used, pcretest
525        now prints out the matched string after a yield of 0 or 1.
526    
527    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
528        Only supported by the JIT compiler at the moment.
529    
530    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
531    
532    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
533        offset of the starting point of the matching process, provided the offsets
534        vector is large enough.
535    
536    17. The \A escape now records a lookbehind value of 1, though its execution
537        does not actually inspect the previous character. This is to ensure that,
538        in partial multi-segment matching, at least one character from the old
539        segment is retained when a new segment is processed. Otherwise, if there
540        are no lookbehinds in the pattern, \A might match incorrectly at the start
541        of a new segment.
542    
543    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
544    
545    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
546        gives some modest performance improvement in 8-bit mode.
547    
548    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
549        be expressed in certain programming languages using Universal Character
550        Names.
551    
552    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
553        which points out that "non characters" are not "characters that may not
554        appear in Unicode strings" but rather "characters that are reserved for
555        internal use and have only local meaning".
556    
557    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
558        there was a conditional group that depended on an assertion, if the
559        assertion was false, the callout that immediately followed the alternation
560        in the condition was skipped when pcre_exec() was used for matching.
561    
562    23. Allow an explicit callout to be inserted before an assertion that is the
563        condition for a conditional group, for compatibility with automatic
564        callouts, which always insert a callout at this point.
565    
566    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
567        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
568    
569    25. (*PRUNE) is now supported by the JIT compiler.
570    
571    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
572    
573    27. Fix the case where there are two or more SKIPs with arguments that may be
574        ignored.
575    
576    28. (*SKIP) is now supported by the JIT compiler.
577    
578    29. (*THEN) is now supported by the JIT compiler.
579    
580    30. Update RunTest with additional test selector options.
581    
582    31. The way PCRE handles backtracking verbs has been changed in two ways.
583    
584        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
585        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
586        backtracking. In some cases this makes it more Perl-compatible, but Perl's
587        rather obscure rules do not always do the same thing.
588    
589        (2) Previously, backtracking verbs were confined within assertions. This is
590        no longer the case for positive assertions, except for (*ACCEPT). Again,
591        this sometimes improves Perl compatibility, and sometimes does not.
592    
593    32. A number of tests that were in test 2 because Perl did things differently
594        have been moved to test 1, because either Perl or PCRE has changed, and
595        these tests are now compatible.
596    
597    32. Backtracking control verbs are now handled in the same way in JIT and
598        interpreter.
599    
600    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
601        contained a forward subroutine reference caused a compile error.
602    
603    34. Auto-detect and optimize limited repetitions in JIT.
604    
605    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
606        blocking (*UTF) etc.
607    
608    36. In the interpreter, maximizing pattern repetitions for characters and
609        character types now use tail recursion, which reduces stack usage.
610    
611    37. The value of the max lookbehind was not correctly preserved if a compiled
612        and saved regex was reloaded on a host of different endianness.
613    
614    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
615        of the compiled pattern block, expand the flags field from 16 to 32 bits
616        because it was almost full.
617    
618    39. Try madvise first before posix_madvise.
619    
620    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
621        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
622        original change locked out all matches of empty strings. This has been
623        changed so that one match of an empty string per line is recognized.
624        Subsequent searches on the same line (for colouring or for --only-matching,
625        for example) do not recognize empty strings.
626    
627    41. Applied a user patch to fix a number of spelling mistakes in comments.
628    
629    42. Data lines longer than 65536 caused pcretest to crash.
630    
631    43. Clarified the data type for length and startoffset arguments for pcre_exec
632        and pcre_dfa_exec in the function-specific man pages, where they were
633        explicitly stated to be in bytes, never having been updated. I also added
634        some clarification to the pcreapi man page.
635    
636    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
637        a segmentation fault.
638    
639    
640    Version 8.32 30-November-2012
641    -----------------------------
642    
643    1.  Improved JIT compiler optimizations for first character search and single
644        character iterators.
645    
646    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
647        Patch by Daniel Richard G.
648    
649    3.  Single character iterator optimizations in the JIT compiler.
650    
651    4.  Improved JIT compiler optimizations for character ranges.
652    
653    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
654        Reported by Giuseppe D'Angelo.
655    
656    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
657        of a line, was being set incorrectly in cases where .* appeared inside
658        atomic brackets at the start of a pattern, or where there was a subsequent
659        *PRUNE or *SKIP.
660    
661    7.  Improved instruction cache flush for POWER/PowerPC.
662        Patch by Daniel Richard G.
663    
664    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
665        grep:
666    
667        (a) There is now no limit to the number of patterns to be matched.
668    
669        (b) An error is given if a pattern is too long.
670    
671        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
672            are now supported.
673    
674        (d) --exclude-from and --include-from (multiple use) have been added.
675    
676        (e) Exclusions and inclusions now apply to all files and directories, not
677            just to those obtained from scanning a directory recursively.
678    
679        (f) Multiple uses of -f and --file-list are now supported.
680    
681        (g) In a Windows environment, the default for -d has been changed from
682            "read" (the GNU grep default) to "skip", because otherwise the presence
683            of a directory in the file list provokes an error.
684    
685        (h) The documentation has been revised and clarified in places.
686    
687    9.  Improve the matching speed of capturing brackets.
688    
689    10. Changed the meaning of \X so that it now matches a Unicode extended
690        grapheme cluster.
691    
692    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
693        out POSIX threads when JIT support is configured.
694    
695    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
696    
697    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
698        structure could go wrong in environments where size_t is not the same size
699        as int.
700    
701    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
702        set.
703    
704    15. The EBCDIC support had decayed; later updates to the code had included
705        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
706        general tidy up of EBCDIC-related issues, and the documentation was also
707        not quite right. There is now a test that can be run on ASCII systems to
708        check some of the EBCDIC-related things (but is it not a full test).
709    
710    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
711        in a small tidy to the code.
712    
713    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
714    
715    18. If the --only-matching (-o) option in pcregrep is specified multiple
716        times, each one causes appropriate output. For example, -o1 -o2 outputs the
717        substrings matched by the 1st and 2nd capturing parentheses. A separating
718        string can be specified by --om-separator (default empty).
719    
720    19. Improving the first n character searches.
721    
722    20. Turn case lists for horizontal and vertical white space into macros so that
723        they are defined only once.
724    
725    21. This set of changes together give more compatible Unicode case-folding
726        behaviour for characters that have more than one other case when UCP
727        support is available.
728    
729        (a) The Unicode property table now has offsets into a new table of sets of
730            three or more characters that are case-equivalent. The MultiStage2.py
731            script that generates these tables (the pcre_ucd.c file) now scans
732            CaseFolding.txt instead of UnicodeData.txt for character case
733            information.
734    
735        (b) The code for adding characters or ranges of characters to a character
736            class has been abstracted into a generalized function that also handles
737            case-independence. In UTF-mode with UCP support, this uses the new data
738            to handle characters with more than one other case.
739    
740        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
741            whose other case is greater than 256 are now correctly matched
742            caselessly. Previously, the high codepoint matched the low one, but not
743            vice versa.
744    
745        (d) The processing of \h, \H, \v, and \ in character classes now makes use
746            of the new class addition function, using character lists defined as
747            macros alongside the case definitions of 20 above.
748    
749        (e) Caseless back references now work with characters that have more than
750            one other case.
751    
752        (f) General caseless matching of characters with more than one other case
753            is supported.
754    
755    22. Unicode character properties were updated from Unicode 6.2.0
756    
757    23. Improved CMake support under Windows. Patch by Daniel Richard G.
758    
759    24. Add support for 32-bit character strings, and UTF-32
760    
761    25. Major JIT compiler update (code refactoring and bugfixing).
762        Experimental Sparc 32 support is added.
763    
764    26. Applied a modified version of Daniel Richard G's patch to create
765        pcre.h.generic and config.h.generic by "make" instead of in the
766        PrepareRelease script.
767    
768    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
769        pcre_compile.c when checking for a zero character.
770    
771    28. Introducing a native interface for JIT. Through this interface, the compiled
772        machine code can be directly executed. The purpose of this interface is to
773        provide fast pattern matching, so several sanity checks are not performed.
774        However, feature tests are still performed. The new interface provides
775        1.4x speedup compared to the old one.
776    
777    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
778        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
779        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
780    
781    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
782        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
783        the "old" RFC 2279). Instead, it ended up passing a negative length to
784        pcre_exec().
785    
786    31. Add support for GCC's visibility feature to hide internal functions.
787    
788    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
789        "unknown -C option" after outputting 0 or 1.
790    
791    33. There is now support for generating a code coverage report for the test
792        suite in environments where gcc is the compiler and lcov is installed. This
793        is mainly for the benefit of the developers.
794    
795    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
796        unaddressable using valgrind annotations, allowing valgrind to detect
797        invalid memory accesses. This is mainly for the benefit of the developers.
798    
799    25. (*UTF) can now be used to start a pattern in any of the three libraries.
800    
801    26. Give configure error if --enable-cpp but no C++ compiler found.
802    
803    
804    Version 8.31 06-July-2012
805    -------------------------
806    
807    1.  Fixing a wrong JIT test case and some compiler warnings.
808    
809    2.  Removed a bashism from the RunTest script.
810    
811    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
812        to unsigned type, result still unsigned" that was given by an MS compiler
813        on encountering the code "-sizeof(xxx)".
814    
815    4.  Partial matching support is added to the JIT compiler.
816    
817    5.  Fixed several bugs concerned with partial matching of items that consist
818        of more than one character:
819    
820        (a) /^(..)\1/ did not partially match "aba" because checking references was
821            done on an "all or nothing" basis. This also applied to repeated
822            references.
823    
824        (b) \R did not give a hard partial match if \r was found at the end of the
825            subject.
826    
827        (c) \X did not give a hard partial match after matching one or more
828            characters at the end of the subject.
829    
830        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
831            a partial match for the string "\r".
832    
833        (e) When newline was set to CRLF, the metacharacter "." did not recognize
834            a partial match for a CR character at the end of the subject string.
835    
836    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
837        running pcretest, the text "(JIT)" added to the output whenever JIT is
838        actually used to run the match.
839    
840    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
841        or /S+[+] with a digit between 1 and 7.
842    
843    8.  OP_NOT now supports any UTF character not just single-byte ones.
844    
845    9.  (*MARK) control verb is now supported by the JIT compiler.
846    
847    10. The command "./RunTest list" lists the available tests without actually
848        running any of them. (Because I keep forgetting what they all are.)
849    
850    11. Add PCRE_INFO_MAXLOOKBEHIND.
851    
852    12. Applied a (slightly modified) user-supplied patch that improves performance
853        when the heap is used for recursion (compiled with --disable-stack-for-
854        recursion). Instead of malloc and free for each heap frame each time a
855        logical recursion happens, frames are retained on a chain and re-used where
856        possible. This sometimes gives as much as 30% improvement.
857    
858    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
859        call.
860    
861    14. As documented, (*COMMIT) is now confined to within a positive assertion.
862    
863    15. It is now possible to link pcretest with libedit as an alternative to
864        libreadline.
865    
866    16. (*COMMIT) control verb is now supported by the JIT compiler.
867    
868    17. The Unicode data tables have been updated to Unicode 6.1.0.
869    
870    18. Added --file-list option to pcregrep.
871    
872    19. Added binary file support to pcregrep, including the -a, --binary-files,
873        -I, and --text options.
874    
875    20. The madvise function is renamed for posix_madvise for QNX compatibility
876        reasons. Fixed by Giuseppe D'Angelo.
877    
878    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
879    
880    22. Changed the option for creating symbolic links for 16-bit man pages from
881        -s to -sf so that re-installing does not cause issues.
882    
883    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
884    
885    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
886        matches in certain environments (the workspace was not being correctly
887        retained). Also added to pcre_dfa_exec() a simple plausibility check on
888        some of the workspace data at the beginning of a restart.
889    
890    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
891        was not doing so when it should - probably a typo introduced by SVN 528
892        (change 8.10/14).
893    
894    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
895        \w+ when the character tables indicated that \x{c4} was a word character.
896        There were several related cases, all because the tests for doing a table
897        lookup were testing for characters less than 127 instead of 255.
898    
899    27. If a pattern contains capturing parentheses that are not used in a match,
900        their slots in the ovector are set to -1. For those that are higher than
901        any matched groups, this happens at the end of processing. In the case when
902        there were back references that the ovector was too small to contain
903        (causing temporary malloc'd memory to be used during matching), and the
904        highest capturing number was not used, memory off the end of the ovector
905        was incorrectly being set to -1. (It was using the size of the temporary
906        memory instead of the true size.)
907    
908    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
909        ovector size, it uses memory at the end of the block that it has got.
910    
911    29. Check for an overlong MARK name and give an error at compile time. The
912        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
913    
914    30. JIT compiler update.
915    
916    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
917        Rill for the patch.
918    
919    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
920    
921    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
922    
923    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
924        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
925        was enabled.
926    
927    35. Improve JIT code generation for greedy plus quantifier.
928    
929    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
930        1 to "aa" instead of to an empty string. The bug affected repeated groups
931        that could potentially match an empty string.
932    
933    37. Optimizing single character iterators in JIT.
934    
935    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
936        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
937        codepoints that are too big for the mode are faulted, and in a UTF mode,
938        disallowed codepoints are also faulted.
939    
940    39. If PCRE was compiled with UTF support, in three places in the DFA
941        matcher there was code that should only have been obeyed in UTF mode, but
942        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
943        processing when bytes with values greater than 127 were present. In 16-bit
944        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
945        both cases the values are those that cannot be the first data item in a UTF
946        character. The three items that might have provoked this were recursions,
947        possessively repeated groups, and atomic groups.
948    
949    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
950        and pcregrep, because some OS require shared objects to be explicitly
951        passed to ld, causing the link step to fail if they are not.
952    
953    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
954        mode, patterns that started with \h* or \R* might be incorrectly matched.
955    
956    
957    Version 8.30 04-February-2012
958    -----------------------------
959    
960    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
961        name is defined in ctype.h.
962    
963    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
964        only in quite long subpatterns.
965    
966    3.  Removed the function pcre_info(), which has been obsolete and deprecated
967        since it was replaced by pcre_fullinfo() in February 2000.
968    
969    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
970        match a (*MARK), and the match failed at the start of the subject, a
971        reference to memory before the start of the subject could occur. This bug
972        was introduced by fix 17 of release 8.21.
973    
974    5.  A reference to an unset group with zero minimum repetition was giving
975        totally wrong answers (in non-JavaScript-compatibility mode). For example,
976        /(another)?(\1?)test/ matched against "hello world test". This bug was
977        introduced in release 8.13.
978    
979    6.  Add support for 16-bit character strings (a large amount of work involving
980        many changes and refactorings).
981    
982    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
983        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
984        from a file.
985    
986    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
987        rounding is not applied in this particular case).
988    
989    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
990        if they appear, or are escaped, in patterns.
991    
992    10. Get rid of a number of -Wunused-but-set-variable warnings.
993    
994    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
995        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
996        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
997        also returns the mark "x". This bug applied to capturing parentheses,
998        non-capturing parentheses, and atomic parentheses. It also applied to some
999        assertions.
1000    
1001    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1002        information out of configure.ac instead of relying on pcre.h.generic, which
1003        is not stored in the repository.
1004    
1005    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1006        -lreadline.
1007    
1008    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1009    
1010    15. Applied Graycode's patch to put the top-level frame on the stack rather
1011        than the heap when not using the stack for recursion. This gives a
1012        performance improvement in many cases when recursion is not deep.
1013    
1014    16. Experimental code added to "pcretest -C" to output the stack frame size.
1015    
1016    
1017    Version 8.21 12-Dec-2011
1018    ------------------------
1019    
1020    1.  Updating the JIT compiler.
1021    
1022    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1023        are added as well.
1024    
1025    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1026        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1027        calling _pcre_jit_exec. Some extra comments are added.
1028    
1029    4.  (*MARK) settings inside atomic groups that do not contain any capturing
1030        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1031        was introduced by change 18 for 8.20.
1032    
1033    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1034        ECMA-262 standard.
1035    
1036    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1037        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1038        This bug was probably introduced by change 9 of 8.13.
1039    
1040    7.  While fixing 6 above, I noticed that a number of other items were being
1041        incorrectly rejected as "not fixed length". This arose partly because newer
1042        opcodes had not been added to the fixed-length checking code. I have (a)
1043        corrected the bug and added tests for these items, and (b) arranged for an
1044        error to occur if an unknown opcode is encountered while checking for fixed
1045        length instead of just assuming "not fixed length". The items that were
1046        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1047        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1048        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1049    
1050    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1051        being incorrectly compiled and would have given unpredicatble results.
1052    
1053    9.  A possessively repeated subpattern with minimum repeat count greater than
1054        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1055        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1056        the first (A) could occur when it should not.
1057    
1058    10. Add a cast and remove a redundant test from the code.
1059    
1060    11. JIT should use pcre_malloc/pcre_free for allocation.
1061    
1062    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1063        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1064        is anything other than /usr, -L is still shown).
1065    
1066    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1067    
1068    14. Perl does not support \N without a following name in a [] class; PCRE now
1069        also gives an error.
1070    
1071    15. If a forward reference was repeated with an upper limit of around 2000,
1072        it caused the error "internal error: overran compiling workspace". The
1073        maximum number of forward references (including repeats) was limited by the
1074        internal workspace, and dependent on the LINK_SIZE. The code has been
1075        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1076        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1077        of around 200,000 forward references. While doing this, I also speeded up
1078        the filling in of repeated forward references.
1079    
1080    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1081        incorrectly expecting the subject to contain another "a" after the start.
1082    
1083    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1084        in the match, the SKIP should be ignored. This was not happening; instead
1085        the SKIP was being treated as NOMATCH. For patterns such as
1086        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1087        tested.
1088    
1089    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1090        now much more compatible with Perl, in particular in cases where the result
1091        is a non-match for a non-anchored pattern. For example, if
1092        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1093        "m", where previously it did not return a name. A side effect of this
1094        change is that for partial matches, the last encountered mark name is
1095        returned, as for non matches. A number of tests that were previously not
1096        Perl-compatible have been moved into the Perl-compatible test files. The
1097        refactoring has had the pleasing side effect of removing one argument from
1098        the match() function, thus reducing its stack requirements.
1099    
1100    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1101        subsequent uses of /S (without +) incorrectly behaved like /S+.
1102    
1103    21. Retrieve executable code size support for the JIT compiler and fixing
1104        some warnings.
1105    
1106    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1107        not work when the shorter character appeared right at the end of the
1108        subject string.
1109    
1110    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1111        systems.
1112    
1113    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1114        output it when the /M option is used in pcretest.
1115    
1116    25. The CheckMan script was not being included in the distribution. Also, added
1117        an explicit "perl" to run Perl scripts from the PrepareRelease script
1118        because this is reportedly needed in Windows.
1119    
1120    26. If study data was being save in a file and studying had not found a set of
1121        "starts with" bytes for the pattern, the data written to the file (though
1122        never used) was taken from uninitialized memory and so caused valgrind to
1123        complain.
1124    
1125    27. Updated RunTest.bat as provided by Sheri Pierce.
1126    
1127    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1128    
1129    29. Computation of memory usage for the table of capturing group names was
1130        giving an unnecessarily large value.
1131    
1132    
1133    Version 8.20 21-Oct-2011
1134    ------------------------
1135    
1136    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1137        a POSIX class. After further experiments with Perl, which convinced me that
1138        Perl has bugs and confusions, a closing square bracket is no longer allowed
1139        in a POSIX name. This bug also affected patterns with classes that started
1140        with full stops.
1141    
1142    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1143        captured substring, but while checking the failing first alternative,
1144        substring 1 is temporarily captured. If the output vector supplied to
1145        pcre_exec() was not big enough for this capture, the yield of the function
1146        was still zero ("insufficient space for captured substrings"). This cannot
1147        be totally fixed without adding another stack variable, which seems a lot
1148        of expense for a edge case. However, I have improved the situation in cases
1149        such as /(a)(b)x|abc/ matched against "abc", where the return code
1150        indicates that fewer than the maximum number of slots in the ovector have
1151        been set.
1152    
1153    3.  Related to (2) above: when there are more back references in a pattern than
1154        slots in the output vector, pcre_exec() uses temporary memory during
1155        matching, and copies in the captures as far as possible afterwards. It was
1156        using the entire output vector, but this conflicts with the specification
1157        that only 2/3 is used for passing back captured substrings. Now it uses
1158        only the first 2/3, for compatibility. This is, of course, another edge
1159        case.
1160    
1161    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1162        main code base, and can be used by building with --enable-jit. When this is
1163        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1164        runtime --no-jit option is given.
1165    
1166    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1167        ovector, the return from the function was zero, implying that there were
1168        other matches that did not fit. The correct "exactly full" value is now
1169        returned.
1170    
1171    6.  If a subpattern that was called recursively or as a subroutine contained
1172        (*PRUNE) or any other control that caused it to give a non-standard return,
1173        invalid errors such as "Error -26 (nested recursion at the same subject
1174        position)" or even infinite loops could occur.
1175    
1176    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1177        computing the minimum length on reaching *ACCEPT, and so ended up with the
1178        wrong value of 1 rather than 0. Further investigation indicates that
1179        computing a minimum subject length in the presence of *ACCEPT is difficult
1180        (think back references, subroutine calls), and so I have changed the code
1181        so that no minimum is registered for a pattern that contains *ACCEPT.
1182    
1183    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1184        it was not handled as intended. [But see 16 below.]
1185    
1186    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1187        Sheri Pierce.
1188    
1189    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1190        the first byte in a match must be "a".
1191    
1192    11. Change 17 for 8.13 increased the recursion depth for patterns like
1193        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1194        pattern contains any instances of (*THEN). If it does not, the old
1195        optimizations are restored. It would be nice to do this on a per-group
1196        basis, but at the moment that is not feasible.
1197    
1198    12. In some environments, the output of pcretest -C is CRLF terminated. This
1199        broke RunTest's code that checks for the link size. A single white space
1200        character after the value is now allowed for.
1201    
1202    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1203        For "fr", it uses the Windows-specific input and output files.
1204    
1205    14. If (*THEN) appeared in a group that was called recursively or as a
1206        subroutine, it did not work as intended. [But see next item.]
1207    
1208    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1209        pattern fragments (but not containing any | characters). If A and B are
1210        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1211        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1212        D. In other words, Perl considers parentheses that do not contain any |
1213        characters to be part of a surrounding alternative, whereas PCRE was
1214        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1215        differently. PCRE now behaves in the same way as Perl, except in the case
1216        of subroutine/recursion calls such as (?1) which have in any case always
1217        been different (but PCRE had them first :-).
1218    
1219    16. Related to 15 above: Perl does not treat the | in a conditional group as
1220        creating alternatives. Such a group is treated in the same way as an
1221        ordinary group without any | characters when processing (*THEN). PCRE has
1222        been changed to match Perl's behaviour.
1223    
1224    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1225        RunGrepTest script failed.
1226    
1227    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1228        inevitable for groups that contain captures, but it can lead to a lot of
1229        stack use in large patterns. The old behaviour has been restored for atomic
1230        groups that do not contain any capturing parentheses.
1231    
1232    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1233        suppress the check for a minimum subject length at run time. (If it was
1234        given to pcre_exec() or pcre_dfa_exec() it did work.)
1235    
1236    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1237        fail to work when decoding hex characters in data strings in EBCDIC
1238        environments.
1239    
1240    21. It appears that in at least one Mac OS environment, the isxdigit() function
1241        is implemented as a macro that evaluates to its argument more than once,
1242        contravening the C 90 Standard (I haven't checked a later standard). There
1243        was an instance in pcretest which caused it to go wrong when processing
1244        \x{...} escapes in subject strings. The has been rewritten to avoid using
1245        things like p++ in the argument of isxdigit().
1246    
1247    
1248    Version 8.13 16-Aug-2011
1249  ------------------------  ------------------------
1250    
1251  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 98  Version 8.13 02-Aug-2011 Line 1342  Version 8.13 02-Aug-2011
1342      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
1343      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
1344      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
1345      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
1346    
1347  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
1348      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
# Line 189  Version 8.13 02-Aug-2011 Line 1433  Version 8.13 02-Aug-2011
1433      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1434      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
1435      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1436      more like Perl.      more like Perl. (But see 8.20/1 above.)
1437    
1438  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1439      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).
# Line 224  Version 8.13 02-Aug-2011 Line 1468  Version 8.13 02-Aug-2011
1468      (a) The default value of the buffer size parameter has been increased from      (a) The default value of the buffer size parameter has been increased from
1469          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
1470    
1471      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1472          PCRE is built.          PCRE is built.
1473    
1474      (c) A --buffer-size=n option has been added to pcregrep, to allow the size      (c) A --buffer-size=n option has been added to pcregrep, to allow the size
# Line 245  Version 8.13 02-Aug-2011 Line 1489  Version 8.13 02-Aug-2011
1489  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1490      complete match instead of a partial match. This bug was dependent on both      complete match instead of a partial match. This bug was dependent on both
1491      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
1492    
1493  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1494      starting byte set, because \b was not being ignored.      starting byte set, because \b was not being ignored.
1495    
1496    
1497  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
# Line 900  Version 7.9 11-Apr-09 Line 2144  Version 7.9 11-Apr-09
2144  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
2145      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
2146      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2147      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2148        8.33.]
2149    
2150  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
2151      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 1143  Version 7.7 07-May-08 Line 2388  Version 7.7 07-May-08
2388      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2389      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2390      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2391      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2392      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2393      was subsequently set up correctly.)      was subsequently set up correctly.)
2394    

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