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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.21  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    9. A reference to a duplicated named group (either a back reference or a test
47       for being set in a conditional) that occurred in a part of the pattern where
48       PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
49       to be incorrectly calculated, leading to overwriting.
50    
51    10. A mutually recursive set of back references such as (\2)(\1) caused a
52        segfault at study time (while trying to find the minimum matching length).
53        The infinite loop is now broken (with the minimum length unset, that is,
54        zero).
55    
56    11. If an assertion that was used as a condition was quantified with a minimum
57        of zero, matching went wrong. In particular, if the whole group had
58        unlimited repetition and could match an empty string, a segfault was
59        likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
60        assertions to be quantified, but not if they are being used as conditions,
61        so the above pattern is faulted by Perl. PCRE has now been changed so that
62        it also rejects such patterns.
63    
64    12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
65        failed to allow the zero-repeat case if pcre2_exec() was called with an
66        ovector too small to capture the group.
67    
68    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
69        Red Hat Product Security:
70    
71        (a) A crash if /K and /F were both set with the option to save the compiled
72        pattern.
73    
74        (b) Another crash if the option to print captured substrings in a callout
75        was combined with setting a null ovector, for example \O\C+ as a subject
76        string.
77    
78    14. A pattern such as "((?2){0,1999}())?", which has a group containing a
79        forward reference repeated a large (but limited) number of times within a
80        repeated outer group that has a zero minimum quantifier, caused incorrect
81        code to be compiled, leading to the error "internal error:
82        previously-checked referenced subpattern not found" when an incorrect
83        memory address was read. This bug was reported as "heap overflow",
84        discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
85        CVE-2015-2325.
86    
87    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
88        call within a group that also contained a recursive back reference caused
89        incorrect code to be compiled. This bug was reported as "heap overflow",
90        discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
91        number CVE-2015-2326.
92    
93    24. Computing the size of the JIT read-only data in advance has been a source
94        of various issues, and new ones are still appear unfortunately. To fix
95        existing and future issues, size computation is eliminated from the code,
96        and replaced by on-demand memory allocation.
97    
98    25. A pattern such as /(?i)[A-`]/, where characters in the other case are
99        adjacent to the end of the range, and the range contained characters with
100        more than one other case, caused incorrect behaviour when compiled in UTF
101        mode. In that example, the range a-j was left out of the class.
102    
103    26. Fix JIT compilation of conditional blocks, which assertion
104        is converted to (*FAIL). E.g: /(?(?!))/.
105    
106    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
107        discovered by the LLVM fuzzer.
108    
109    28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
110        when this assertion was used as a condition, for example (?(?!)a|b). In
111        pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
112        error about an unsupported item.
113    
114    29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
115        possessification code could take exponential time to complete. A recursion
116        depth limit of 1000 has been imposed to limit the resources used by this
117        optimization.
118    
119    30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
120        such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
121        because \S ensures they are all in the class. The code for doing this was
122        interacting badly with the code for computing the amount of space needed to
123        compile the pattern, leading to a buffer overflow. This bug was discovered
124        by the LLVM fuzzer.
125    
126    31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
127        other kinds of group caused stack overflow at compile time. This bug was
128        discovered by the LLVM fuzzer.
129    
130    32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
131        between a subroutine call and its quantifier was incorrectly compiled,
132        leading to buffer overflow or other errors. This bug was discovered by the
133        LLVM fuzzer.
134    
135    33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
136        assertion after (?(. The code was failing to check the character after
137        (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
138        was discovered by the LLVM fuzzer.
139    
140    34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
141        a fixed maximum following a group that contains a subroutine reference was
142        incorrectly compiled and could trigger buffer overflow. This bug was
143        discovered by the LLVM fuzzer.
144    
145    35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
146        caused a stack overflow instead of the diagnosis of a non-fixed length
147        lookbehind assertion. This bug was discovered by the LLVM fuzzer.
148    
149    
150    Version 8.36 26-September-2014
151    ------------------------------
152    
153    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
154        -Wmissing-field-initializers and -Wunused-parameter.
155    
156    2.  The tests for quantifiers being too big (greater than 65535) were being
157        applied after reading the number, and stupidly assuming that integer
158        overflow would give a negative number. The tests are now applied as the
159        numbers are read.
160    
161    3.  Tidy code in pcre_exec.c where two branches that used to be different are
162        now the same.
163    
164    4.  The JIT compiler did not generate match limit checks for certain
165        bracketed expressions with quantifiers. This may lead to exponential
166        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
167        issue should be resolved now.
168    
169    5.  Fixed an issue, which occures when nested alternatives are optimized
170        with table jumps.
171    
172    6.  Inserted two casts and changed some ints to size_t in the light of some
173        reported 64-bit compiler warnings (Bugzilla 1477).
174    
175    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
176        an empty string, which sometimes were behaving incorrectly in the
177        interpreter (though correctly in the JIT matcher). This pcretest input is
178        an example:
179    
180          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
181          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
182    
183        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
184        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
185        for an empty string was breaking the inner loop and carrying on at a lower
186        level, when possessive repeated groups should always return to a higher
187        level as they have no backtrack points in them. The empty string test now
188        occurs at the outer level.
189    
190    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
191        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
192    
193    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
194        doesn't).
195    
196    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
197        to hold a pattern to be incorrectly computed (too small) when there were
198        named back references to duplicated names. This could cause "internal
199        error: code overflow" or "double free or corruption" or other memory
200        handling errors.
201    
202    11. When named subpatterns had the same prefixes, back references could be
203        confused. For example, in this pattern:
204    
205          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
206    
207        the reference to 'Name' was incorrectly treated as a reference to a
208        duplicate name.
209    
210    12. A pattern such as /^s?c/mi8 where the optional character has more than
211        one "other case" was incorrectly compiled such that it would only try to
212        match starting at "c".
213    
214    13. When a pattern starting with \s was studied, VT was not included in the
215        list of possible starting characters; this should have been part of the
216        8.34/18 patch.
217    
218    14. If a character class started [\Qx]... where x is any character, the class
219        was incorrectly terminated at the ].
220    
221    15. If a pattern that started with a caseless match for a character with more
222        than one "other case" was studied, PCRE did not set up the starting code
223        unit bit map for the list of possible characters. Now it does. This is an
224        optimization improvement, not a bug fix.
225    
226    16. The Unicode data tables have been updated to Unicode 7.0.0.
227    
228    17. Fixed a number of memory leaks in pcregrep.
229    
230    18. Avoid a compiler warning (from some compilers) for a function call with
231        a cast that removes "const" from an lvalue by using an intermediate
232        variable (to which the compiler does not object).
233    
234    19. Incorrect code was compiled if a group that contained an internal recursive
235        back reference was optional (had quantifier with a minimum of zero). This
236        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
237        caused segmentation faults because of stack overflows at compile time.
238    
239    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
240        group that is quantified with an indefinite repeat, caused a compile-time
241        loop which used up all the system stack and provoked a segmentation fault.
242        This was not the same bug as 19 above.
243    
244    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
245        Patch by Mike Frysinger.
246    
247    
248    Version 8.35 04-April-2014
249    --------------------------
250    
251    1.  A new flag is set, when property checks are present in an XCLASS.
252        When this flag is not set, PCRE can perform certain optimizations
253        such as studying these XCLASS-es.
254    
255    2.  The auto-possessification of character sets were improved: a normal
256        and an extended character set can be compared now. Furthermore
257        the JIT compiler optimizes more character set checks.
258    
259    3.  Got rid of some compiler warnings for potentially uninitialized variables
260        that show up only when compiled with -O2.
261    
262    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
263        of a match later then the end of the match. The pcretest program was not
264        handling the case sensibly - it was outputting from the start to the next
265        binary zero. It now reports this situation in a message, and outputs the
266        text from the end to the start.
267    
268    5.  Fast forward search is improved in JIT. Instead of the first three
269        characters, any three characters with fixed position can be searched.
270        Search order: first, last, middle.
271    
272    6.  Improve character range checks in JIT. Characters are read by an inprecise
273        function now, which returns with an unknown value if the character code is
274        above a certain threshold (e.g: 256). The only limitation is that the value
275        must be bigger than the threshold as well. This function is useful when
276        the characters above the threshold are handled in the same way.
277    
278    7.  The macros whose names start with RAWUCHAR are placeholders for a future
279        mode in which only the bottom 21 bits of 32-bit data items are used. To
280        make this more memorable for those maintaining the code, the names have
281        been changed to start with UCHAR21, and an extensive comment has been added
282        to their definition.
283    
284    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
285        to the export list in Makefile.am (they were accidentally omitted from the
286        8.34 tarball).
287    
288    9.  The informational output from pcretest used the phrase "starting byte set"
289        which is inappropriate for the 16-bit and 32-bit libraries. As the output
290        for "first char" and "need char" really means "non-UTF-char", I've changed
291        "byte" to "char", and slightly reworded the output. The documentation about
292        these values has also been (I hope) clarified.
293    
294    10. Another JIT related optimization: use table jumps for selecting the correct
295        backtracking path, when more than four alternatives are present inside a
296        bracket.
297    
298    11. Empty match is not possible, when the minimum length is greater than zero,
299        and there is no \K in the pattern. JIT should avoid empty match checks in
300        such cases.
301    
302    12. In a caseless character class with UCP support, when a character with more
303        than one alternative case was not the first character of a range, not all
304        the alternative cases were added to the class. For example, s and \x{17f}
305        are both alternative cases for S: the class [RST] was handled correctly,
306        but [R-T] was not.
307    
308    13. The configure.ac file always checked for pthread support when JIT was
309        enabled. This is not used in Windows, so I have put this test inside a
310        check for the presence of windows.h (which was already tested for).
311    
312    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
313        The algorithm provides a way to skip certain starting offsets, and usually
314        faster than linear prefix searches.
315    
316    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
317        as for 'fr_FR' and 'french'. For some reason, however, it then used the
318        Windows-specific input and output files, which have 'french' screwed in.
319        So this could never have worked. One of the problems with locales is that
320        they aren't always the same. I have now updated RunTest so that it checks
321        the output of the locale test (test 3) against three different output
322        files, and it allows the test to pass if any one of them matches. With luck
323        this should make the test pass on some versions of Solaris where it was
324        failing. Because of the uncertainty, the script did not used to stop if
325        test 3 failed; it now does. If further versions of a French locale ever
326        come to light, they can now easily be added.
327    
328    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
329        there was a message during ./configure, but it did not stop. This now
330        provokes an error. The invalid example in README has been corrected.
331        If a value less than the minimum is given, the minimum value has always
332        been used, but now a warning is given.
333    
334    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
335        was a bug in the test system, which is now fixed. Also, the list of various
336        configurations that are tested for each release did not have one with both
337        16/32 bits and --enable-bar-anycrlf. It now does.
338    
339    18. pcretest was missing "-C bsr" for displaying the \R default setting.
340    
341    19. Little endian PowerPC systems are supported now by the JIT compiler.
342    
343    20. The fast forward newline mechanism could enter to an infinite loop on
344        certain invalid UTF-8 input. Although we don't support these cases
345        this issue can be fixed by a performance optimization.
346    
347    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
348        not take account if existing stack usage. There is now a new global
349        variable called pcre_stack_guard that can be set to point to an external
350        function to check stack availability. It is called at the start of
351        processing every parenthesized group.
352    
353    22. A typo in the code meant that in ungreedy mode the max/min qualifier
354        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
355        not match "ab".
356    
357    23. When UTF was disabled, the JIT program reported some incorrect compile
358        errors. These messages are silenced now.
359    
360    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
361        compiler.
362    
363    25. Change all the temporary files used in RunGrepTest to be different to those
364        used by RunTest so that the tests can be run simultaneously, for example by
365        "make -j check".
366    
367    
368    Version 8.34 15-December-2013
369    -----------------------------
370    
371    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
372        executable memory. Patch inspired by Carsten Klein.
373    
374    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
375        this macro is never tested and has no effect, because the work to support
376        coverage involves only compiling and linking options and special targets in
377        the Makefile. The comment in config.h implied that defining the macro would
378        enable coverage support, which is totally false. There was also support for
379        setting this macro in the CMake files (my fault, I just copied it from
380        configure). SUPPORT_GCOV has now been removed.
381    
382    3.  Make a small performance improvement in strlen16() and strlen32() in
383        pcretest.
384    
385    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
386        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
387        these cases). There was also one in pcretest.c.
388    
389    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
390    
391    6.  In UTF mode, the code for checking whether a group could match an empty
392        string (which is used for indefinitely repeated groups to allow for
393        breaking an infinite loop) was broken when the group contained a repeated
394        negated single-character class with a character that occupied more than one
395        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
396        UTF-8 mode). The effect was undefined: the group might or might not be
397        deemed as matching an empty string, or the program might have crashed.
398    
399    7.  The code for checking whether a group could match an empty string was not
400        recognizing that \h, \H, \v, \V, and \R must match a character.
401    
402    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
403        an empty string. If it can, pcretest shows this in its information output.
404    
405    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
406        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
407        matched by pcre_exec() without using JIT:
408    
409        (a) If the rest of the pattern did not match after a maximal run of
410            grapheme clusters, the code for backing up to try with fewer of them
411            did not always back up over a full grapheme when characters that do not
412            have the modifier quality were involved, e.g. Hangul syllables.
413    
414        (b) If the match point in a subject started with modifier character, and
415            there was no match, the code could incorrectly back up beyond the match
416            point, and potentially beyond the first character in the subject,
417            leading to a segfault or an incorrect match result.
418    
419    10. A conditional group with an assertion condition could lead to PCRE
420        recording an incorrect first data item for a match if no other first data
421        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
422        first data item, and therefore matched "ca" after "c" instead of at the
423        start.
424    
425    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
426        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
427    
428    12. The source of pcregrep now includes z/OS-specific code so that it can be
429        compiled for z/OS as part of the special z/OS distribution.
430    
431    13. Added the -T and -TM options to pcretest.
432    
433    14. The code in pcre_compile.c for creating the table of named capturing groups
434        has been refactored. Instead of creating the table dynamically during the
435        actual compiling pass, the information is remembered during the pre-compile
436        pass (on the stack unless there are more than 20 named groups, in which
437        case malloc() is used) and the whole table is created before the actual
438        compile happens. This has simplified the code (it is now nearly 150 lines
439        shorter) and prepared the way for better handling of references to groups
440        with duplicate names.
441    
442    15. A back reference to a named subpattern when there is more than one of the
443        same name now checks them in the order in which they appear in the pattern.
444        The first one that is set is used for the reference. Previously only the
445        first one was inspected. This change makes PCRE more compatible with Perl.
446    
447    16. Unicode character properties were updated from Unicode 6.3.0.
448    
449    17. The compile-time code for auto-possessification has been refactored, based
450        on a patch by Zoltan Herczeg. It now happens after instead of during
451        compilation. The code is cleaner, and more cases are handled. The option
452        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
453        options in pcretest are provided to set it. It can also be set by
454        (*NO_AUTO_POSSESS) at the start of a pattern.
455    
456    18. The character VT has been added to the default ("C" locale) set of
457        characters that match \s and are generally treated as white space,
458        following this same change in Perl 5.18. There is now no difference between
459        "Perl space" and "POSIX space". Whether VT is treated as white space in
460        other locales depends on the locale.
461    
462    19. The code for checking named groups as conditions, either for being set or
463        for being recursed, has been refactored (this is related to 14 and 15
464        above). Processing unduplicated named groups should now be as fast at
465        numerical groups, and processing duplicated groups should be faster than
466        before.
467    
468    20. Two patches to the CMake build system, by Alexander Barkov:
469    
470          (1) Replace the "source" command by "." in CMakeLists.txt because
471              "source" is a bash-ism.
472    
473          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
474              without these the CMake build does not work on Solaris.
475    
476    21. Perl has changed its handling of \8 and \9. If there is no previously
477        encountered capturing group of those numbers, they are treated as the
478        literal characters 8 and 9 instead of a binary zero followed by the
479        literals. PCRE now does the same.
480    
481    22. Following Perl, added \o{} to specify codepoints in octal, making it
482        possible to specify values greater than 0777 and also making them
483        unambiguous.
484    
485    23. Perl now gives an error for missing closing braces after \x{... instead of
486        treating the string as literal. PCRE now does the same.
487    
488    24. RunTest used to grumble if an inappropriate test was selected explicitly,
489        but just skip it when running all tests. This make it awkward to run ranges
490        of tests when one of them was inappropriate. Now it just skips any
491        inappropriate tests, as it always did when running all tests.
492    
493    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
494        character types such as \d or \w, too many callouts were inserted, and the
495        data that they returned was rubbish.
496    
497    26. In UCP mode, \s was not matching two of the characters that Perl matches,
498        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
499        were matched by \h. The code has now been refactored so that the lists of
500        the horizontal and vertical whitespace characters used for \h and \v (which
501        are defined only in one place) are now also used for \s.
502    
503    27. Add JIT support for the 64 bit TileGX architecture.
504        Patch by Jiong Wang (Tilera Corporation).
505    
506    28. Possessive quantifiers for classes (both explicit and automatically
507        generated) now use special opcodes instead of wrapping in ONCE brackets.
508    
509    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
510        (because it's meaningless), this was not happening when PCRE_CASELESS was
511        set. Not wrong, but inefficient.
512    
513    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
514        properties for \w, \d, etc) is present in a test regex. Otherwise if the
515        test contains no characters greater than 255, Perl doesn't realise it
516        should be using Unicode semantics.
517    
518    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
519        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
520        does in Unicode mode.
521    
522    32. Added the "forbid" facility to pcretest so that putting tests into the
523        wrong test files can sometimes be quickly detected.
524    
525    33. There is now a limit (default 250) on the depth of nesting of parentheses.
526        This limit is imposed to control the amount of system stack used at compile
527        time. It can be changed at build time by --with-parens-nest-limit=xxx or
528        the equivalent in CMake.
529    
530    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
531        errors. Perl warns for these when in warning mode, but PCRE has no facility
532        for giving warnings.
533    
534    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
535        However, this was not working for (?!) because it is optimized to (*FAIL),
536        for which PCRE does not allow quantifiers. The optimization is now disabled
537        when a quantifier follows (?!). I can't see any use for this, but it makes
538        things uniform.
539    
540    36. Perl no longer allows group names to start with digits, so I have made this
541        change also in PCRE. It simplifies the code a bit.
542    
543    37. In extended mode, Perl ignores spaces before a + that indicates a
544        possessive quantifier. PCRE allowed a space before the quantifier, but not
545        before the possessive +. It now does.
546    
547    38. The use of \K (reset reported match start) within a repeated possessive
548        group such as (a\Kb)*+ was not working.
549    
550    40. Document that the same character tables must be used at compile time and
551        run time, and that the facility to pass tables to pcre_exec() and
552        pcre_dfa_exec() is for use only with saved/restored patterns.
553    
554    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
555        features for Builds with MSVC:
556    
557        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
558           builds). The .rc files can be used to set FileDescription and many other
559           attributes.
560    
561        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
562           This allows higher-level build scripts which want .pdb files to avoid
563           hard-coding the exact files needed."
564    
565    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
566        mean "start of word" and "end of word", respectively, as a transition aid.
567    
568    43. A minimizing repeat of a class containing codepoints greater than 255 in
569        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
570        compiled to use the heap for recursion.
571    
572    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
573        is configured.
574    
575    
576    Version 8.33 28-May-2013
577    ------------------------
578    
579    1.  Added 'U' to some constants that are compared to unsigned integers, to
580        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
581        variables that are added to signed variables, to ensure the result is
582        signed and can be negated.
583    
584    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
585        CMake config files.
586    
587    3.  Revise the creation of config.h.generic so that all boolean macros are
588        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
589        overriding via -D on the command line possible.
590    
591    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
592        to unsigned int is reported to make a quite noticeable speed difference in
593        a specific Windows environment. Testing on Linux did also appear to show
594        some benefit (and it is clearly not harmful). Also fixed the definition of
595        Xop which should be unsigned.
596    
597    5.  Related to (4), changing the definition of the intermediate variable cc
598        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
599        improvements.
600    
601    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
602        unnecessary spaces.
603    
604    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
605        and later.
606    
607    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
608    
609    9.  Optimizing fast_forward_start_bits in JIT.
610    
611    10. Adding support for callouts in JIT, and fixing some issues revealed
612        during this work. Namely:
613    
614        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
615    
616        (b) Minimum length was not checked before the matching is started.
617    
618    11. The value of capture_last that is passed to callouts was incorrect in some
619        cases when there was a capture on one path that was subsequently abandoned
620        after a backtrack. Also, the capture_last value is now reset after a
621        recursion, since all captures are also reset in this case.
622    
623    12. The interpreter no longer returns the "too many substrings" error in the
624        case when an overflowing capture is in a branch that is subsequently
625        abandoned after a backtrack.
626    
627    13. In the pathological case when an offset vector of size 2 is used, pcretest
628        now prints out the matched string after a yield of 0 or 1.
629    
630    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
631        Only supported by the JIT compiler at the moment.
632    
633    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
634    
635    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
636        offset of the starting point of the matching process, provided the offsets
637        vector is large enough.
638    
639    17. The \A escape now records a lookbehind value of 1, though its execution
640        does not actually inspect the previous character. This is to ensure that,
641        in partial multi-segment matching, at least one character from the old
642        segment is retained when a new segment is processed. Otherwise, if there
643        are no lookbehinds in the pattern, \A might match incorrectly at the start
644        of a new segment.
645    
646    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
647    
648    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
649        gives some modest performance improvement in 8-bit mode.
650    
651    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
652        be expressed in certain programming languages using Universal Character
653        Names.
654    
655    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
656        which points out that "non characters" are not "characters that may not
657        appear in Unicode strings" but rather "characters that are reserved for
658        internal use and have only local meaning".
659    
660    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
661        there was a conditional group that depended on an assertion, if the
662        assertion was false, the callout that immediately followed the alternation
663        in the condition was skipped when pcre_exec() was used for matching.
664    
665    23. Allow an explicit callout to be inserted before an assertion that is the
666        condition for a conditional group, for compatibility with automatic
667        callouts, which always insert a callout at this point.
668    
669    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
670        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
671    
672    25. (*PRUNE) is now supported by the JIT compiler.
673    
674    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
675    
676    27. Fix the case where there are two or more SKIPs with arguments that may be
677        ignored.
678    
679    28. (*SKIP) is now supported by the JIT compiler.
680    
681    29. (*THEN) is now supported by the JIT compiler.
682    
683    30. Update RunTest with additional test selector options.
684    
685    31. The way PCRE handles backtracking verbs has been changed in two ways.
686    
687        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
688        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
689        backtracking. In some cases this makes it more Perl-compatible, but Perl's
690        rather obscure rules do not always do the same thing.
691    
692        (2) Previously, backtracking verbs were confined within assertions. This is
693        no longer the case for positive assertions, except for (*ACCEPT). Again,
694        this sometimes improves Perl compatibility, and sometimes does not.
695    
696    32. A number of tests that were in test 2 because Perl did things differently
697        have been moved to test 1, because either Perl or PCRE has changed, and
698        these tests are now compatible.
699    
700    32. Backtracking control verbs are now handled in the same way in JIT and
701        interpreter.
702    
703    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
704        contained a forward subroutine reference caused a compile error.
705    
706    34. Auto-detect and optimize limited repetitions in JIT.
707    
708    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
709        blocking (*UTF) etc.
710    
711    36. In the interpreter, maximizing pattern repetitions for characters and
712        character types now use tail recursion, which reduces stack usage.
713    
714    37. The value of the max lookbehind was not correctly preserved if a compiled
715        and saved regex was reloaded on a host of different endianness.
716    
717    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
718        of the compiled pattern block, expand the flags field from 16 to 32 bits
719        because it was almost full.
720    
721    39. Try madvise first before posix_madvise.
722    
723    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
724        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
725        original change locked out all matches of empty strings. This has been
726        changed so that one match of an empty string per line is recognized.
727        Subsequent searches on the same line (for colouring or for --only-matching,
728        for example) do not recognize empty strings.
729    
730    41. Applied a user patch to fix a number of spelling mistakes in comments.
731    
732    42. Data lines longer than 65536 caused pcretest to crash.
733    
734    43. Clarified the data type for length and startoffset arguments for pcre_exec
735        and pcre_dfa_exec in the function-specific man pages, where they were
736        explicitly stated to be in bytes, never having been updated. I also added
737        some clarification to the pcreapi man page.
738    
739    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
740        a segmentation fault.
741    
742    
743    Version 8.32 30-November-2012
744    -----------------------------
745    
746    1.  Improved JIT compiler optimizations for first character search and single
747        character iterators.
748    
749    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
750        Patch by Daniel Richard G.
751    
752    3.  Single character iterator optimizations in the JIT compiler.
753    
754    4.  Improved JIT compiler optimizations for character ranges.
755    
756    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
757        Reported by Giuseppe D'Angelo.
758    
759    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
760        of a line, was being set incorrectly in cases where .* appeared inside
761        atomic brackets at the start of a pattern, or where there was a subsequent
762        *PRUNE or *SKIP.
763    
764    7.  Improved instruction cache flush for POWER/PowerPC.
765        Patch by Daniel Richard G.
766    
767    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
768        grep:
769    
770        (a) There is now no limit to the number of patterns to be matched.
771    
772        (b) An error is given if a pattern is too long.
773    
774        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
775            are now supported.
776    
777        (d) --exclude-from and --include-from (multiple use) have been added.
778    
779        (e) Exclusions and inclusions now apply to all files and directories, not
780            just to those obtained from scanning a directory recursively.
781    
782        (f) Multiple uses of -f and --file-list are now supported.
783    
784        (g) In a Windows environment, the default for -d has been changed from
785            "read" (the GNU grep default) to "skip", because otherwise the presence
786            of a directory in the file list provokes an error.
787    
788        (h) The documentation has been revised and clarified in places.
789    
790    9.  Improve the matching speed of capturing brackets.
791    
792    10. Changed the meaning of \X so that it now matches a Unicode extended
793        grapheme cluster.
794    
795    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
796        out POSIX threads when JIT support is configured.
797    
798    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
799    
800    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
801        structure could go wrong in environments where size_t is not the same size
802        as int.
803    
804    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
805        set.
806    
807    15. The EBCDIC support had decayed; later updates to the code had included
808        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
809        general tidy up of EBCDIC-related issues, and the documentation was also
810        not quite right. There is now a test that can be run on ASCII systems to
811        check some of the EBCDIC-related things (but is it not a full test).
812    
813    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
814        in a small tidy to the code.
815    
816    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
817    
818    18. If the --only-matching (-o) option in pcregrep is specified multiple
819        times, each one causes appropriate output. For example, -o1 -o2 outputs the
820        substrings matched by the 1st and 2nd capturing parentheses. A separating
821        string can be specified by --om-separator (default empty).
822    
823    19. Improving the first n character searches.
824    
825    20. Turn case lists for horizontal and vertical white space into macros so that
826        they are defined only once.
827    
828    21. This set of changes together give more compatible Unicode case-folding
829        behaviour for characters that have more than one other case when UCP
830        support is available.
831    
832        (a) The Unicode property table now has offsets into a new table of sets of
833            three or more characters that are case-equivalent. The MultiStage2.py
834            script that generates these tables (the pcre_ucd.c file) now scans
835            CaseFolding.txt instead of UnicodeData.txt for character case
836            information.
837    
838        (b) The code for adding characters or ranges of characters to a character
839            class has been abstracted into a generalized function that also handles
840            case-independence. In UTF-mode with UCP support, this uses the new data
841            to handle characters with more than one other case.
842    
843        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
844            whose other case is greater than 256 are now correctly matched
845            caselessly. Previously, the high codepoint matched the low one, but not
846            vice versa.
847    
848        (d) The processing of \h, \H, \v, and \ in character classes now makes use
849            of the new class addition function, using character lists defined as
850            macros alongside the case definitions of 20 above.
851    
852        (e) Caseless back references now work with characters that have more than
853            one other case.
854    
855        (f) General caseless matching of characters with more than one other case
856            is supported.
857    
858    22. Unicode character properties were updated from Unicode 6.2.0
859    
860    23. Improved CMake support under Windows. Patch by Daniel Richard G.
861    
862    24. Add support for 32-bit character strings, and UTF-32
863    
864    25. Major JIT compiler update (code refactoring and bugfixing).
865        Experimental Sparc 32 support is added.
866    
867    26. Applied a modified version of Daniel Richard G's patch to create
868        pcre.h.generic and config.h.generic by "make" instead of in the
869        PrepareRelease script.
870    
871    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
872        pcre_compile.c when checking for a zero character.
873    
874    28. Introducing a native interface for JIT. Through this interface, the compiled
875        machine code can be directly executed. The purpose of this interface is to
876        provide fast pattern matching, so several sanity checks are not performed.
877        However, feature tests are still performed. The new interface provides
878        1.4x speedup compared to the old one.
879    
880    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
881        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
882        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
883    
884    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
885        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
886        the "old" RFC 2279). Instead, it ended up passing a negative length to
887        pcre_exec().
888    
889    31. Add support for GCC's visibility feature to hide internal functions.
890    
891    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
892        "unknown -C option" after outputting 0 or 1.
893    
894    33. There is now support for generating a code coverage report for the test
895        suite in environments where gcc is the compiler and lcov is installed. This
896        is mainly for the benefit of the developers.
897    
898    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
899        unaddressable using valgrind annotations, allowing valgrind to detect
900        invalid memory accesses. This is mainly for the benefit of the developers.
901    
902    25. (*UTF) can now be used to start a pattern in any of the three libraries.
903    
904    26. Give configure error if --enable-cpp but no C++ compiler found.
905    
906    
907    Version 8.31 06-July-2012
908    -------------------------
909    
910    1.  Fixing a wrong JIT test case and some compiler warnings.
911    
912    2.  Removed a bashism from the RunTest script.
913    
914    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
915        to unsigned type, result still unsigned" that was given by an MS compiler
916        on encountering the code "-sizeof(xxx)".
917    
918    4.  Partial matching support is added to the JIT compiler.
919    
920    5.  Fixed several bugs concerned with partial matching of items that consist
921        of more than one character:
922    
923        (a) /^(..)\1/ did not partially match "aba" because checking references was
924            done on an "all or nothing" basis. This also applied to repeated
925            references.
926    
927        (b) \R did not give a hard partial match if \r was found at the end of the
928            subject.
929    
930        (c) \X did not give a hard partial match after matching one or more
931            characters at the end of the subject.
932    
933        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
934            a partial match for the string "\r".
935    
936        (e) When newline was set to CRLF, the metacharacter "." did not recognize
937            a partial match for a CR character at the end of the subject string.
938    
939    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
940        running pcretest, the text "(JIT)" added to the output whenever JIT is
941        actually used to run the match.
942    
943    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
944        or /S+[+] with a digit between 1 and 7.
945    
946    8.  OP_NOT now supports any UTF character not just single-byte ones.
947    
948    9.  (*MARK) control verb is now supported by the JIT compiler.
949    
950    10. The command "./RunTest list" lists the available tests without actually
951        running any of them. (Because I keep forgetting what they all are.)
952    
953    11. Add PCRE_INFO_MAXLOOKBEHIND.
954    
955    12. Applied a (slightly modified) user-supplied patch that improves performance
956        when the heap is used for recursion (compiled with --disable-stack-for-
957        recursion). Instead of malloc and free for each heap frame each time a
958        logical recursion happens, frames are retained on a chain and re-used where
959        possible. This sometimes gives as much as 30% improvement.
960    
961    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
962        call.
963    
964    14. As documented, (*COMMIT) is now confined to within a positive assertion.
965    
966    15. It is now possible to link pcretest with libedit as an alternative to
967        libreadline.
968    
969    16. (*COMMIT) control verb is now supported by the JIT compiler.
970    
971    17. The Unicode data tables have been updated to Unicode 6.1.0.
972    
973    18. Added --file-list option to pcregrep.
974    
975    19. Added binary file support to pcregrep, including the -a, --binary-files,
976        -I, and --text options.
977    
978    20. The madvise function is renamed for posix_madvise for QNX compatibility
979        reasons. Fixed by Giuseppe D'Angelo.
980    
981    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
982    
983    22. Changed the option for creating symbolic links for 16-bit man pages from
984        -s to -sf so that re-installing does not cause issues.
985    
986    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
987    
988    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
989        matches in certain environments (the workspace was not being correctly
990        retained). Also added to pcre_dfa_exec() a simple plausibility check on
991        some of the workspace data at the beginning of a restart.
992    
993    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
994        was not doing so when it should - probably a typo introduced by SVN 528
995        (change 8.10/14).
996    
997    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
998        \w+ when the character tables indicated that \x{c4} was a word character.
999        There were several related cases, all because the tests for doing a table
1000        lookup were testing for characters less than 127 instead of 255.
1001    
1002    27. If a pattern contains capturing parentheses that are not used in a match,
1003        their slots in the ovector are set to -1. For those that are higher than
1004        any matched groups, this happens at the end of processing. In the case when
1005        there were back references that the ovector was too small to contain
1006        (causing temporary malloc'd memory to be used during matching), and the
1007        highest capturing number was not used, memory off the end of the ovector
1008        was incorrectly being set to -1. (It was using the size of the temporary
1009        memory instead of the true size.)
1010    
1011    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1012        ovector size, it uses memory at the end of the block that it has got.
1013    
1014    29. Check for an overlong MARK name and give an error at compile time. The
1015        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1016    
1017    30. JIT compiler update.
1018    
1019    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1020        Rill for the patch.
1021    
1022    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1023    
1024    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1025    
1026    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1027        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1028        was enabled.
1029    
1030    35. Improve JIT code generation for greedy plus quantifier.
1031    
1032    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1033        1 to "aa" instead of to an empty string. The bug affected repeated groups
1034        that could potentially match an empty string.
1035    
1036    37. Optimizing single character iterators in JIT.
1037    
1038    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1039        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1040        codepoints that are too big for the mode are faulted, and in a UTF mode,
1041        disallowed codepoints are also faulted.
1042    
1043    39. If PCRE was compiled with UTF support, in three places in the DFA
1044        matcher there was code that should only have been obeyed in UTF mode, but
1045        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1046        processing when bytes with values greater than 127 were present. In 16-bit
1047        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1048        both cases the values are those that cannot be the first data item in a UTF
1049        character. The three items that might have provoked this were recursions,
1050        possessively repeated groups, and atomic groups.
1051    
1052    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1053        and pcregrep, because some OS require shared objects to be explicitly
1054        passed to ld, causing the link step to fail if they are not.
1055    
1056    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1057        mode, patterns that started with \h* or \R* might be incorrectly matched.
1058    
1059    
1060    Version 8.30 04-February-2012
1061    -----------------------------
1062    
1063    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
1064        name is defined in ctype.h.
1065    
1066    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
1067        only in quite long subpatterns.
1068    
1069    3.  Removed the function pcre_info(), which has been obsolete and deprecated
1070        since it was replaced by pcre_fullinfo() in February 2000.
1071    
1072    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
1073        match a (*MARK), and the match failed at the start of the subject, a
1074        reference to memory before the start of the subject could occur. This bug
1075        was introduced by fix 17 of release 8.21.
1076    
1077    5.  A reference to an unset group with zero minimum repetition was giving
1078        totally wrong answers (in non-JavaScript-compatibility mode). For example,
1079        /(another)?(\1?)test/ matched against "hello world test". This bug was
1080        introduced in release 8.13.
1081    
1082    6.  Add support for 16-bit character strings (a large amount of work involving
1083        many changes and refactorings).
1084    
1085    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1086        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1087        from a file.
1088    
1089    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1090        rounding is not applied in this particular case).
1091    
1092    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1093        if they appear, or are escaped, in patterns.
1094    
1095    10. Get rid of a number of -Wunused-but-set-variable warnings.
1096    
1097    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1098        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1099        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1100        also returns the mark "x". This bug applied to capturing parentheses,
1101        non-capturing parentheses, and atomic parentheses. It also applied to some
1102        assertions.
1103    
1104    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1105        information out of configure.ac instead of relying on pcre.h.generic, which
1106        is not stored in the repository.
1107    
1108    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1109        -lreadline.
1110    
1111    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1112    
1113    15. Applied Graycode's patch to put the top-level frame on the stack rather
1114        than the heap when not using the stack for recursion. This gives a
1115        performance improvement in many cases when recursion is not deep.
1116    
1117    16. Experimental code added to "pcretest -C" to output the stack frame size.
1118    
1119    
1120    Version 8.21 12-Dec-2011
1121    ------------------------
1122    
1123  1.  Updating the JIT compiler.  1.  Updating the JIT compiler.
1124    
# Line 13  Version 8.21 Line 1129  Version 8.21
1129      PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before      PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1130      calling _pcre_jit_exec. Some extra comments are added.      calling _pcre_jit_exec. Some extra comments are added.
1131    
1132  4.  Mark settings inside atomic groups that do not contain any capturing  4.  (*MARK) settings inside atomic groups that do not contain any capturing
1133      parentheses, for example, (?>a(*:m)), were not being passed out. This bug      parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1134      was introduced by change 18 for 8.20.      was introduced by change 18 for 8.20.
1135    
# Line 22  Version 8.21 Line 1138  Version 8.21
1138    
1139  6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were  6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1140      erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.      erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1141      This bug was probably introduced by change 9 of 8.13.      This bug was probably introduced by change 9 of 8.13.
1142    
1143  7.  While fixing 6 above, I noticed that a number of other items were being  7.  While fixing 6 above, I noticed that a number of other items were being
1144      incorrectly rejected as "not fixed length". This arose partly because newer      incorrectly rejected as "not fixed length". This arose partly because newer
1145      opcodes had not been added to the fixed-length checking code. I have (a)      opcodes had not been added to the fixed-length checking code. I have (a)
1146      corrected the bug and added tests for these items, and (b) arranged for an      corrected the bug and added tests for these items, and (b) arranged for an
1147      error to occur if an unknown opcode is encountered while checking for fixed      error to occur if an unknown opcode is encountered while checking for fixed
1148      length instead of just assuming "not fixed length". The items that were      length instead of just assuming "not fixed length". The items that were
1149      rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),      rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1150      (*THEN), \h, \H, \v, \V, and single character negative classes with fixed      (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1151      repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.      repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1152    
1153  8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was  8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1154      being incorrectly compiled and would have given unpredicatble results.      being incorrectly compiled and would have given unpredicatble results.
1155    
1156  9.  A possessively repeated subpattern with minimum repeat count greater than  9.  A possessively repeated subpattern with minimum repeat count greater than
1157      one behaved incorrectly. For example, (A){2,}+ behaved as if it was      one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1158      (A)(A)++ which meant that, after a subsequent mismatch, backtracking into      (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1159      the first (A) could occur when it should not.      the first (A) could occur when it should not.
1160    
1161  10. Add a cast and remove a redundant test from the code.  10. Add a cast and remove a redundant test from the code.
1162    
1163  11. JIT should use pcre_malloc/pcre_free for allocation.  11. JIT should use pcre_malloc/pcre_free for allocation.
1164    
1165  12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems  12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1166      best practice nowadays, and helps with cross-compiling. (If the exec_prefix      best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1167      is anything other than /usr, -L is still shown).      is anything other than /usr, -L is still shown).
1168    
1169    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1170    
1171    14. Perl does not support \N without a following name in a [] class; PCRE now
1172        also gives an error.
1173    
1174    15. If a forward reference was repeated with an upper limit of around 2000,
1175        it caused the error "internal error: overran compiling workspace". The
1176        maximum number of forward references (including repeats) was limited by the
1177        internal workspace, and dependent on the LINK_SIZE. The code has been
1178        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1179        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1180        of around 200,000 forward references. While doing this, I also speeded up
1181        the filling in of repeated forward references.
1182    
1183    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1184        incorrectly expecting the subject to contain another "a" after the start.
1185    
1186    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1187        in the match, the SKIP should be ignored. This was not happening; instead
1188        the SKIP was being treated as NOMATCH. For patterns such as
1189        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1190        tested.
1191    
1192    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1193        now much more compatible with Perl, in particular in cases where the result
1194        is a non-match for a non-anchored pattern. For example, if
1195        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1196        "m", where previously it did not return a name. A side effect of this
1197        change is that for partial matches, the last encountered mark name is
1198        returned, as for non matches. A number of tests that were previously not
1199        Perl-compatible have been moved into the Perl-compatible test files. The
1200        refactoring has had the pleasing side effect of removing one argument from
1201        the match() function, thus reducing its stack requirements.
1202    
1203    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1204        subsequent uses of /S (without +) incorrectly behaved like /S+.
1205    
1206    21. Retrieve executable code size support for the JIT compiler and fixing
1207        some warnings.
1208    
1209    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1210        not work when the shorter character appeared right at the end of the
1211        subject string.
1212    
1213    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1214        systems.
1215    
1216    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1217        output it when the /M option is used in pcretest.
1218    
1219    25. The CheckMan script was not being included in the distribution. Also, added
1220        an explicit "perl" to run Perl scripts from the PrepareRelease script
1221        because this is reportedly needed in Windows.
1222    
1223    26. If study data was being save in a file and studying had not found a set of
1224        "starts with" bytes for the pattern, the data written to the file (though
1225        never used) was taken from uninitialized memory and so caused valgrind to
1226        complain.
1227    
1228    27. Updated RunTest.bat as provided by Sheri Pierce.
1229    
1230    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1231    
1232    29. Computation of memory usage for the table of capturing group names was
1233        giving an unnecessarily large value.
1234    
1235    
1236  Version 8.20 21-Oct-2011  Version 8.20 21-Oct-2011
# Line 1065  Version 7.9 11-Apr-09 Line 2247  Version 7.9 11-Apr-09
2247  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
2248      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
2249      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2250      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2251        8.33.]
2252    
2253  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
2254      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 1308  Version 7.7 07-May-08 Line 2491  Version 7.7 07-May-08
2491      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2492      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2493      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2494      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2495      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2496      was subsequently set up correctly.)      was subsequently set up correctly.)
2497    

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