ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 740 by zherczeg, Mon Oct 31 06:10:14 2011 UTC revision 1545 by ph10, Wed Apr 8 16:34:24 2015 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.21  Version 8.37 xx-xxx-2015
5  ------------  ------------------------
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".
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.
17    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
18        unrecognized modifier, a crash could occur.
20    4.  An attempt to do global matching in pcretest with a zero-length ovector
21        caused a crash.
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.
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.
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))/.
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.
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.
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).
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.
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.
68    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
69        Red Hat Product Security:
71        (a) A crash if /K and /F were both set with the option to save the compiled
72        pattern.
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.
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.
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.
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.
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.
103    26. Fix JIT compilation of conditional blocks, which assertion
104        is converted to (*FAIL). E.g: /(?(?!))/.
106    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
107        discovered by the LLVM fuzzer.
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.
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.
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.
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.
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.
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.
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.
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.
149    36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
150        (e.g. /(?<=\Ka)/) could make pcregrep loop.
152    37. There was a similar problem to 36 in pcretest for global matches.
154    38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
155        and a subsequent item in the pattern caused a non-match, backtracking over
156        the repeated \X did not stop, but carried on past the start of the subject,
157        causing reference to random memory and/or a segfault.  This bug was
158        discovered by the LLVM fuzzer.
161    Version 8.36 26-September-2014
162    ------------------------------
164    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
165        -Wmissing-field-initializers and -Wunused-parameter.
167    2.  The tests for quantifiers being too big (greater than 65535) were being
168        applied after reading the number, and stupidly assuming that integer
169        overflow would give a negative number. The tests are now applied as the
170        numbers are read.
172    3.  Tidy code in pcre_exec.c where two branches that used to be different are
173        now the same.
175    4.  The JIT compiler did not generate match limit checks for certain
176        bracketed expressions with quantifiers. This may lead to exponential
177        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
178        issue should be resolved now.
180    5.  Fixed an issue, which occures when nested alternatives are optimized
181        with table jumps.
183    6.  Inserted two casts and changed some ints to size_t in the light of some
184        reported 64-bit compiler warnings (Bugzilla 1477).
186    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
187        an empty string, which sometimes were behaving incorrectly in the
188        interpreter (though correctly in the JIT matcher). This pcretest input is
189        an example:
191          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
194        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
195        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
196        for an empty string was breaking the inner loop and carrying on at a lower
197        level, when possessive repeated groups should always return to a higher
198        level as they have no backtrack points in them. The empty string test now
199        occurs at the outer level.
201    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
202        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
204    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
205        doesn't).
207    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
208        to hold a pattern to be incorrectly computed (too small) when there were
209        named back references to duplicated names. This could cause "internal
210        error: code overflow" or "double free or corruption" or other memory
211        handling errors.
213    11. When named subpatterns had the same prefixes, back references could be
214        confused. For example, in this pattern:
216          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
218        the reference to 'Name' was incorrectly treated as a reference to a
219        duplicate name.
221    12. A pattern such as /^s?c/mi8 where the optional character has more than
222        one "other case" was incorrectly compiled such that it would only try to
223        match starting at "c".
225    13. When a pattern starting with \s was studied, VT was not included in the
226        list of possible starting characters; this should have been part of the
227        8.34/18 patch.
229    14. If a character class started [\Qx]... where x is any character, the class
230        was incorrectly terminated at the ].
232    15. If a pattern that started with a caseless match for a character with more
233        than one "other case" was studied, PCRE did not set up the starting code
234        unit bit map for the list of possible characters. Now it does. This is an
235        optimization improvement, not a bug fix.
237    16. The Unicode data tables have been updated to Unicode 7.0.0.
239    17. Fixed a number of memory leaks in pcregrep.
241    18. Avoid a compiler warning (from some compilers) for a function call with
242        a cast that removes "const" from an lvalue by using an intermediate
243        variable (to which the compiler does not object).
245    19. Incorrect code was compiled if a group that contained an internal recursive
246        back reference was optional (had quantifier with a minimum of zero). This
247        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
248        caused segmentation faults because of stack overflows at compile time.
250    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
251        group that is quantified with an indefinite repeat, caused a compile-time
252        loop which used up all the system stack and provoked a segmentation fault.
253        This was not the same bug as 19 above.
255    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
256        Patch by Mike Frysinger.
259    Version 8.35 04-April-2014
260    --------------------------
262    1.  A new flag is set, when property checks are present in an XCLASS.
263        When this flag is not set, PCRE can perform certain optimizations
264        such as studying these XCLASS-es.
266    2.  The auto-possessification of character sets were improved: a normal
267        and an extended character set can be compared now. Furthermore
268        the JIT compiler optimizes more character set checks.
270    3.  Got rid of some compiler warnings for potentially uninitialized variables
271        that show up only when compiled with -O2.
273    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
274        of a match later then the end of the match. The pcretest program was not
275        handling the case sensibly - it was outputting from the start to the next
276        binary zero. It now reports this situation in a message, and outputs the
277        text from the end to the start.
279    5.  Fast forward search is improved in JIT. Instead of the first three
280        characters, any three characters with fixed position can be searched.
281        Search order: first, last, middle.
283    6.  Improve character range checks in JIT. Characters are read by an inprecise
284        function now, which returns with an unknown value if the character code is
285        above a certain threshold (e.g: 256). The only limitation is that the value
286        must be bigger than the threshold as well. This function is useful when
287        the characters above the threshold are handled in the same way.
289    7.  The macros whose names start with RAWUCHAR are placeholders for a future
290        mode in which only the bottom 21 bits of 32-bit data items are used. To
291        make this more memorable for those maintaining the code, the names have
292        been changed to start with UCHAR21, and an extensive comment has been added
293        to their definition.
295    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
296        to the export list in Makefile.am (they were accidentally omitted from the
297        8.34 tarball).
299    9.  The informational output from pcretest used the phrase "starting byte set"
300        which is inappropriate for the 16-bit and 32-bit libraries. As the output
301        for "first char" and "need char" really means "non-UTF-char", I've changed
302        "byte" to "char", and slightly reworded the output. The documentation about
303        these values has also been (I hope) clarified.
305    10. Another JIT related optimization: use table jumps for selecting the correct
306        backtracking path, when more than four alternatives are present inside a
307        bracket.
309    11. Empty match is not possible, when the minimum length is greater than zero,
310        and there is no \K in the pattern. JIT should avoid empty match checks in
311        such cases.
313    12. In a caseless character class with UCP support, when a character with more
314        than one alternative case was not the first character of a range, not all
315        the alternative cases were added to the class. For example, s and \x{17f}
316        are both alternative cases for S: the class [RST] was handled correctly,
317        but [R-T] was not.
319    13. The configure.ac file always checked for pthread support when JIT was
320        enabled. This is not used in Windows, so I have put this test inside a
321        check for the presence of windows.h (which was already tested for).
323    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
324        The algorithm provides a way to skip certain starting offsets, and usually
325        faster than linear prefix searches.
327    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
328        as for 'fr_FR' and 'french'. For some reason, however, it then used the
329        Windows-specific input and output files, which have 'french' screwed in.
330        So this could never have worked. One of the problems with locales is that
331        they aren't always the same. I have now updated RunTest so that it checks
332        the output of the locale test (test 3) against three different output
333        files, and it allows the test to pass if any one of them matches. With luck
334        this should make the test pass on some versions of Solaris where it was
335        failing. Because of the uncertainty, the script did not used to stop if
336        test 3 failed; it now does. If further versions of a French locale ever
337        come to light, they can now easily be added.
339    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
340        there was a message during ./configure, but it did not stop. This now
341        provokes an error. The invalid example in README has been corrected.
342        If a value less than the minimum is given, the minimum value has always
343        been used, but now a warning is given.
345    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
346        was a bug in the test system, which is now fixed. Also, the list of various
347        configurations that are tested for each release did not have one with both
348        16/32 bits and --enable-bar-anycrlf. It now does.
350    18. pcretest was missing "-C bsr" for displaying the \R default setting.
352    19. Little endian PowerPC systems are supported now by the JIT compiler.
354    20. The fast forward newline mechanism could enter to an infinite loop on
355        certain invalid UTF-8 input. Although we don't support these cases
356        this issue can be fixed by a performance optimization.
358    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
359        not take account if existing stack usage. There is now a new global
360        variable called pcre_stack_guard that can be set to point to an external
361        function to check stack availability. It is called at the start of
362        processing every parenthesized group.
364    22. A typo in the code meant that in ungreedy mode the max/min qualifier
365        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
366        not match "ab".
368    23. When UTF was disabled, the JIT program reported some incorrect compile
369        errors. These messages are silenced now.
371    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
372        compiler.
374    25. Change all the temporary files used in RunGrepTest to be different to those
375        used by RunTest so that the tests can be run simultaneously, for example by
376        "make -j check".
379    Version 8.34 15-December-2013
380    -----------------------------
382    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
383        executable memory. Patch inspired by Carsten Klein.
385    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
386        this macro is never tested and has no effect, because the work to support
387        coverage involves only compiling and linking options and special targets in
388        the Makefile. The comment in config.h implied that defining the macro would
389        enable coverage support, which is totally false. There was also support for
390        setting this macro in the CMake files (my fault, I just copied it from
391        configure). SUPPORT_GCOV has now been removed.
393    3.  Make a small performance improvement in strlen16() and strlen32() in
394        pcretest.
396    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
397        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
398        these cases). There was also one in pcretest.c.
400    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
402    6.  In UTF mode, the code for checking whether a group could match an empty
403        string (which is used for indefinitely repeated groups to allow for
404        breaking an infinite loop) was broken when the group contained a repeated
405        negated single-character class with a character that occupied more than one
406        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
407        UTF-8 mode). The effect was undefined: the group might or might not be
408        deemed as matching an empty string, or the program might have crashed.
410    7.  The code for checking whether a group could match an empty string was not
411        recognizing that \h, \H, \v, \V, and \R must match a character.
413    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
414        an empty string. If it can, pcretest shows this in its information output.
416    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
417        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
418        matched by pcre_exec() without using JIT:
420        (a) If the rest of the pattern did not match after a maximal run of
421            grapheme clusters, the code for backing up to try with fewer of them
422            did not always back up over a full grapheme when characters that do not
423            have the modifier quality were involved, e.g. Hangul syllables.
425        (b) If the match point in a subject started with modifier character, and
426            there was no match, the code could incorrectly back up beyond the match
427            point, and potentially beyond the first character in the subject,
428            leading to a segfault or an incorrect match result.
430    10. A conditional group with an assertion condition could lead to PCRE
431        recording an incorrect first data item for a match if no other first data
432        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
433        first data item, and therefore matched "ca" after "c" instead of at the
434        start.
436    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
437        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
439    12. The source of pcregrep now includes z/OS-specific code so that it can be
440        compiled for z/OS as part of the special z/OS distribution.
442    13. Added the -T and -TM options to pcretest.
444    14. The code in pcre_compile.c for creating the table of named capturing groups
445        has been refactored. Instead of creating the table dynamically during the
446        actual compiling pass, the information is remembered during the pre-compile
447        pass (on the stack unless there are more than 20 named groups, in which
448        case malloc() is used) and the whole table is created before the actual
449        compile happens. This has simplified the code (it is now nearly 150 lines
450        shorter) and prepared the way for better handling of references to groups
451        with duplicate names.
453    15. A back reference to a named subpattern when there is more than one of the
454        same name now checks them in the order in which they appear in the pattern.
455        The first one that is set is used for the reference. Previously only the
456        first one was inspected. This change makes PCRE more compatible with Perl.
458    16. Unicode character properties were updated from Unicode 6.3.0.
460    17. The compile-time code for auto-possessification has been refactored, based
461        on a patch by Zoltan Herczeg. It now happens after instead of during
462        compilation. The code is cleaner, and more cases are handled. The option
463        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
464        options in pcretest are provided to set it. It can also be set by
465        (*NO_AUTO_POSSESS) at the start of a pattern.
467    18. The character VT has been added to the default ("C" locale) set of
468        characters that match \s and are generally treated as white space,
469        following this same change in Perl 5.18. There is now no difference between
470        "Perl space" and "POSIX space". Whether VT is treated as white space in
471        other locales depends on the locale.
473    19. The code for checking named groups as conditions, either for being set or
474        for being recursed, has been refactored (this is related to 14 and 15
475        above). Processing unduplicated named groups should now be as fast at
476        numerical groups, and processing duplicated groups should be faster than
477        before.
479    20. Two patches to the CMake build system, by Alexander Barkov:
481          (1) Replace the "source" command by "." in CMakeLists.txt because
482              "source" is a bash-ism.
484          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
485              without these the CMake build does not work on Solaris.
487    21. Perl has changed its handling of \8 and \9. If there is no previously
488        encountered capturing group of those numbers, they are treated as the
489        literal characters 8 and 9 instead of a binary zero followed by the
490        literals. PCRE now does the same.
492    22. Following Perl, added \o{} to specify codepoints in octal, making it
493        possible to specify values greater than 0777 and also making them
494        unambiguous.
496    23. Perl now gives an error for missing closing braces after \x{... instead of
497        treating the string as literal. PCRE now does the same.
499    24. RunTest used to grumble if an inappropriate test was selected explicitly,
500        but just skip it when running all tests. This make it awkward to run ranges
501        of tests when one of them was inappropriate. Now it just skips any
502        inappropriate tests, as it always did when running all tests.
504    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
505        character types such as \d or \w, too many callouts were inserted, and the
506        data that they returned was rubbish.
508    26. In UCP mode, \s was not matching two of the characters that Perl matches,
509        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
510        were matched by \h. The code has now been refactored so that the lists of
511        the horizontal and vertical whitespace characters used for \h and \v (which
512        are defined only in one place) are now also used for \s.
514    27. Add JIT support for the 64 bit TileGX architecture.
515        Patch by Jiong Wang (Tilera Corporation).
517    28. Possessive quantifiers for classes (both explicit and automatically
518        generated) now use special opcodes instead of wrapping in ONCE brackets.
520    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
521        (because it's meaningless), this was not happening when PCRE_CASELESS was
522        set. Not wrong, but inefficient.
524    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
525        properties for \w, \d, etc) is present in a test regex. Otherwise if the
526        test contains no characters greater than 255, Perl doesn't realise it
527        should be using Unicode semantics.
529    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
530        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
531        does in Unicode mode.
533    32. Added the "forbid" facility to pcretest so that putting tests into the
534        wrong test files can sometimes be quickly detected.
536    33. There is now a limit (default 250) on the depth of nesting of parentheses.
537        This limit is imposed to control the amount of system stack used at compile
538        time. It can be changed at build time by --with-parens-nest-limit=xxx or
539        the equivalent in CMake.
541    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
542        errors. Perl warns for these when in warning mode, but PCRE has no facility
543        for giving warnings.
545    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
546        However, this was not working for (?!) because it is optimized to (*FAIL),
547        for which PCRE does not allow quantifiers. The optimization is now disabled
548        when a quantifier follows (?!). I can't see any use for this, but it makes
549        things uniform.
551    36. Perl no longer allows group names to start with digits, so I have made this
552        change also in PCRE. It simplifies the code a bit.
554    37. In extended mode, Perl ignores spaces before a + that indicates a
555        possessive quantifier. PCRE allowed a space before the quantifier, but not
556        before the possessive +. It now does.
558    38. The use of \K (reset reported match start) within a repeated possessive
559        group such as (a\Kb)*+ was not working.
561    40. Document that the same character tables must be used at compile time and
562        run time, and that the facility to pass tables to pcre_exec() and
563        pcre_dfa_exec() is for use only with saved/restored patterns.
565    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
566        features for Builds with MSVC:
568        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
569           builds). The .rc files can be used to set FileDescription and many other
570           attributes.
572        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
573           This allows higher-level build scripts which want .pdb files to avoid
574           hard-coding the exact files needed."
576    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
577        mean "start of word" and "end of word", respectively, as a transition aid.
579    43. A minimizing repeat of a class containing codepoints greater than 255 in
580        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
581        compiled to use the heap for recursion.
583    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
584        is configured.
587    Version 8.33 28-May-2013
588    ------------------------
590    1.  Added 'U' to some constants that are compared to unsigned integers, to
591        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
592        variables that are added to signed variables, to ensure the result is
593        signed and can be negated.
595    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
596        CMake config files.
598    3.  Revise the creation of config.h.generic so that all boolean macros are
599        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
600        overriding via -D on the command line possible.
602    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
603        to unsigned int is reported to make a quite noticeable speed difference in
604        a specific Windows environment. Testing on Linux did also appear to show
605        some benefit (and it is clearly not harmful). Also fixed the definition of
606        Xop which should be unsigned.
608    5.  Related to (4), changing the definition of the intermediate variable cc
609        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
610        improvements.
612    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
613        unnecessary spaces.
615    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
616        and later.
618    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
620    9.  Optimizing fast_forward_start_bits in JIT.
622    10. Adding support for callouts in JIT, and fixing some issues revealed
623        during this work. Namely:
625        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
627        (b) Minimum length was not checked before the matching is started.
629    11. The value of capture_last that is passed to callouts was incorrect in some
630        cases when there was a capture on one path that was subsequently abandoned
631        after a backtrack. Also, the capture_last value is now reset after a
632        recursion, since all captures are also reset in this case.
634    12. The interpreter no longer returns the "too many substrings" error in the
635        case when an overflowing capture is in a branch that is subsequently
636        abandoned after a backtrack.
638    13. In the pathological case when an offset vector of size 2 is used, pcretest
639        now prints out the matched string after a yield of 0 or 1.
641    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
642        Only supported by the JIT compiler at the moment.
644    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
646    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
647        offset of the starting point of the matching process, provided the offsets
648        vector is large enough.
650    17. The \A escape now records a lookbehind value of 1, though its execution
651        does not actually inspect the previous character. This is to ensure that,
652        in partial multi-segment matching, at least one character from the old
653        segment is retained when a new segment is processed. Otherwise, if there
654        are no lookbehinds in the pattern, \A might match incorrectly at the start
655        of a new segment.
657    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
659    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
660        gives some modest performance improvement in 8-bit mode.
662    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
663        be expressed in certain programming languages using Universal Character
664        Names.
666    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
667        which points out that "non characters" are not "characters that may not
668        appear in Unicode strings" but rather "characters that are reserved for
669        internal use and have only local meaning".
671    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
672        there was a conditional group that depended on an assertion, if the
673        assertion was false, the callout that immediately followed the alternation
674        in the condition was skipped when pcre_exec() was used for matching.
676    23. Allow an explicit callout to be inserted before an assertion that is the
677        condition for a conditional group, for compatibility with automatic
678        callouts, which always insert a callout at this point.
680    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
681        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
683    25. (*PRUNE) is now supported by the JIT compiler.
685    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
687    27. Fix the case where there are two or more SKIPs with arguments that may be
688        ignored.
690    28. (*SKIP) is now supported by the JIT compiler.
692    29. (*THEN) is now supported by the JIT compiler.
694    30. Update RunTest with additional test selector options.
696    31. The way PCRE handles backtracking verbs has been changed in two ways.
698        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
699        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
700        backtracking. In some cases this makes it more Perl-compatible, but Perl's
701        rather obscure rules do not always do the same thing.
703        (2) Previously, backtracking verbs were confined within assertions. This is
704        no longer the case for positive assertions, except for (*ACCEPT). Again,
705        this sometimes improves Perl compatibility, and sometimes does not.
707    32. A number of tests that were in test 2 because Perl did things differently
708        have been moved to test 1, because either Perl or PCRE has changed, and
709        these tests are now compatible.
711    32. Backtracking control verbs are now handled in the same way in JIT and
712        interpreter.
714    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
715        contained a forward subroutine reference caused a compile error.
717    34. Auto-detect and optimize limited repetitions in JIT.
719    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
720        blocking (*UTF) etc.
722    36. In the interpreter, maximizing pattern repetitions for characters and
723        character types now use tail recursion, which reduces stack usage.
725    37. The value of the max lookbehind was not correctly preserved if a compiled
726        and saved regex was reloaded on a host of different endianness.
728    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
729        of the compiled pattern block, expand the flags field from 16 to 32 bits
730        because it was almost full.
732    39. Try madvise first before posix_madvise.
734    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
735        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
736        original change locked out all matches of empty strings. This has been
737        changed so that one match of an empty string per line is recognized.
738        Subsequent searches on the same line (for colouring or for --only-matching,
739        for example) do not recognize empty strings.
741    41. Applied a user patch to fix a number of spelling mistakes in comments.
743    42. Data lines longer than 65536 caused pcretest to crash.
745    43. Clarified the data type for length and startoffset arguments for pcre_exec
746        and pcre_dfa_exec in the function-specific man pages, where they were
747        explicitly stated to be in bytes, never having been updated. I also added
748        some clarification to the pcreapi man page.
750    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
751        a segmentation fault.
754    Version 8.32 30-November-2012
755    -----------------------------
757    1.  Improved JIT compiler optimizations for first character search and single
758        character iterators.
760    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
761        Patch by Daniel Richard G.
763    3.  Single character iterator optimizations in the JIT compiler.
765    4.  Improved JIT compiler optimizations for character ranges.
767    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
768        Reported by Giuseppe D'Angelo.
770    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
771        of a line, was being set incorrectly in cases where .* appeared inside
772        atomic brackets at the start of a pattern, or where there was a subsequent
773        *PRUNE or *SKIP.
775    7.  Improved instruction cache flush for POWER/PowerPC.
776        Patch by Daniel Richard G.
778    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
779        grep:
781        (a) There is now no limit to the number of patterns to be matched.
783        (b) An error is given if a pattern is too long.
785        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
786            are now supported.
788        (d) --exclude-from and --include-from (multiple use) have been added.
790        (e) Exclusions and inclusions now apply to all files and directories, not
791            just to those obtained from scanning a directory recursively.
793        (f) Multiple uses of -f and --file-list are now supported.
795        (g) In a Windows environment, the default for -d has been changed from
796            "read" (the GNU grep default) to "skip", because otherwise the presence
797            of a directory in the file list provokes an error.
799        (h) The documentation has been revised and clarified in places.
801    9.  Improve the matching speed of capturing brackets.
803    10. Changed the meaning of \X so that it now matches a Unicode extended
804        grapheme cluster.
806    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
807        out POSIX threads when JIT support is configured.
809    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
811    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
812        structure could go wrong in environments where size_t is not the same size
813        as int.
815    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
816        set.
818    15. The EBCDIC support had decayed; later updates to the code had included
819        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
820        general tidy up of EBCDIC-related issues, and the documentation was also
821        not quite right. There is now a test that can be run on ASCII systems to
822        check some of the EBCDIC-related things (but is it not a full test).
824    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
825        in a small tidy to the code.
827    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
829    18. If the --only-matching (-o) option in pcregrep is specified multiple
830        times, each one causes appropriate output. For example, -o1 -o2 outputs the
831        substrings matched by the 1st and 2nd capturing parentheses. A separating
832        string can be specified by --om-separator (default empty).
834    19. Improving the first n character searches.
836    20. Turn case lists for horizontal and vertical white space into macros so that
837        they are defined only once.
839    21. This set of changes together give more compatible Unicode case-folding
840        behaviour for characters that have more than one other case when UCP
841        support is available.
843        (a) The Unicode property table now has offsets into a new table of sets of
844            three or more characters that are case-equivalent. The MultiStage2.py
845            script that generates these tables (the pcre_ucd.c file) now scans
846            CaseFolding.txt instead of UnicodeData.txt for character case
847            information.
849        (b) The code for adding characters or ranges of characters to a character
850            class has been abstracted into a generalized function that also handles
851            case-independence. In UTF-mode with UCP support, this uses the new data
852            to handle characters with more than one other case.
854        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
855            whose other case is greater than 256 are now correctly matched
856            caselessly. Previously, the high codepoint matched the low one, but not
857            vice versa.
859        (d) The processing of \h, \H, \v, and \ in character classes now makes use
860            of the new class addition function, using character lists defined as
861            macros alongside the case definitions of 20 above.
863        (e) Caseless back references now work with characters that have more than
864            one other case.
866        (f) General caseless matching of characters with more than one other case
867            is supported.
869    22. Unicode character properties were updated from Unicode 6.2.0
871    23. Improved CMake support under Windows. Patch by Daniel Richard G.
873    24. Add support for 32-bit character strings, and UTF-32
875    25. Major JIT compiler update (code refactoring and bugfixing).
876        Experimental Sparc 32 support is added.
878    26. Applied a modified version of Daniel Richard G's patch to create
879        pcre.h.generic and config.h.generic by "make" instead of in the
880        PrepareRelease script.
882    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
883        pcre_compile.c when checking for a zero character.
885    28. Introducing a native interface for JIT. Through this interface, the compiled
886        machine code can be directly executed. The purpose of this interface is to
887        provide fast pattern matching, so several sanity checks are not performed.
888        However, feature tests are still performed. The new interface provides
889        1.4x speedup compared to the old one.
891    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
892        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
893        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
895    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
896        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
897        the "old" RFC 2279). Instead, it ended up passing a negative length to
898        pcre_exec().
900    31. Add support for GCC's visibility feature to hide internal functions.
902    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
903        "unknown -C option" after outputting 0 or 1.
905    33. There is now support for generating a code coverage report for the test
906        suite in environments where gcc is the compiler and lcov is installed. This
907        is mainly for the benefit of the developers.
909    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
910        unaddressable using valgrind annotations, allowing valgrind to detect
911        invalid memory accesses. This is mainly for the benefit of the developers.
913    25. (*UTF) can now be used to start a pattern in any of the three libraries.
915    26. Give configure error if --enable-cpp but no C++ compiler found.
918    Version 8.31 06-July-2012
919    -------------------------
921    1.  Fixing a wrong JIT test case and some compiler warnings.
923    2.  Removed a bashism from the RunTest script.
925    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
926        to unsigned type, result still unsigned" that was given by an MS compiler
927        on encountering the code "-sizeof(xxx)".
929    4.  Partial matching support is added to the JIT compiler.
931    5.  Fixed several bugs concerned with partial matching of items that consist
932        of more than one character:
934        (a) /^(..)\1/ did not partially match "aba" because checking references was
935            done on an "all or nothing" basis. This also applied to repeated
936            references.
938        (b) \R did not give a hard partial match if \r was found at the end of the
939            subject.
941        (c) \X did not give a hard partial match after matching one or more
942            characters at the end of the subject.
944        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
945            a partial match for the string "\r".
947        (e) When newline was set to CRLF, the metacharacter "." did not recognize
948            a partial match for a CR character at the end of the subject string.
950    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
951        running pcretest, the text "(JIT)" added to the output whenever JIT is
952        actually used to run the match.
954    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
955        or /S+[+] with a digit between 1 and 7.
957    8.  OP_NOT now supports any UTF character not just single-byte ones.
959    9.  (*MARK) control verb is now supported by the JIT compiler.
961    10. The command "./RunTest list" lists the available tests without actually
962        running any of them. (Because I keep forgetting what they all are.)
966    12. Applied a (slightly modified) user-supplied patch that improves performance
967        when the heap is used for recursion (compiled with --disable-stack-for-
968        recursion). Instead of malloc and free for each heap frame each time a
969        logical recursion happens, frames are retained on a chain and re-used where
970        possible. This sometimes gives as much as 30% improvement.
972    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
973        call.
975    14. As documented, (*COMMIT) is now confined to within a positive assertion.
977    15. It is now possible to link pcretest with libedit as an alternative to
978        libreadline.
980    16. (*COMMIT) control verb is now supported by the JIT compiler.
982    17. The Unicode data tables have been updated to Unicode 6.1.0.
984    18. Added --file-list option to pcregrep.
986    19. Added binary file support to pcregrep, including the -a, --binary-files,
987        -I, and --text options.
989    20. The madvise function is renamed for posix_madvise for QNX compatibility
990        reasons. Fixed by Giuseppe D'Angelo.
992    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
994    22. Changed the option for creating symbolic links for 16-bit man pages from
995        -s to -sf so that re-installing does not cause issues.
997    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
999    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1000        matches in certain environments (the workspace was not being correctly
1001        retained). Also added to pcre_dfa_exec() a simple plausibility check on
1002        some of the workspace data at the beginning of a restart.
1004    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1005        was not doing so when it should - probably a typo introduced by SVN 528
1006        (change 8.10/14).
1008    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1009        \w+ when the character tables indicated that \x{c4} was a word character.
1010        There were several related cases, all because the tests for doing a table
1011        lookup were testing for characters less than 127 instead of 255.
1013    27. If a pattern contains capturing parentheses that are not used in a match,
1014        their slots in the ovector are set to -1. For those that are higher than
1015        any matched groups, this happens at the end of processing. In the case when
1016        there were back references that the ovector was too small to contain
1017        (causing temporary malloc'd memory to be used during matching), and the
1018        highest capturing number was not used, memory off the end of the ovector
1019        was incorrectly being set to -1. (It was using the size of the temporary
1020        memory instead of the true size.)
1022    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1023        ovector size, it uses memory at the end of the block that it has got.
1025    29. Check for an overlong MARK name and give an error at compile time. The
1026        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1028    30. JIT compiler update.
1030    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1031        Rill for the patch.
1033    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1035    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1037    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1038        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1039        was enabled.
1041    35. Improve JIT code generation for greedy plus quantifier.
1043    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1044        1 to "aa" instead of to an empty string. The bug affected repeated groups
1045        that could potentially match an empty string.
1047    37. Optimizing single character iterators in JIT.
1049    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1050        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1051        codepoints that are too big for the mode are faulted, and in a UTF mode,
1052        disallowed codepoints are also faulted.
1054    39. If PCRE was compiled with UTF support, in three places in the DFA
1055        matcher there was code that should only have been obeyed in UTF mode, but
1056        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1057        processing when bytes with values greater than 127 were present. In 16-bit
1058        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1059        both cases the values are those that cannot be the first data item in a UTF
1060        character. The three items that might have provoked this were recursions,
1061        possessively repeated groups, and atomic groups.
1063    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1064        and pcregrep, because some OS require shared objects to be explicitly
1065        passed to ld, causing the link step to fail if they are not.
1067    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1068        mode, patterns that started with \h* or \R* might be incorrectly matched.
1071    Version 8.30 04-February-2012
1072    -----------------------------
1074    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
1075        name is defined in ctype.h.
1077    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
1078        only in quite long subpatterns.
1080    3.  Removed the function pcre_info(), which has been obsolete and deprecated
1081        since it was replaced by pcre_fullinfo() in February 2000.
1083    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
1084        match a (*MARK), and the match failed at the start of the subject, a
1085        reference to memory before the start of the subject could occur. This bug
1086        was introduced by fix 17 of release 8.21.
1088    5.  A reference to an unset group with zero minimum repetition was giving
1089        totally wrong answers (in non-JavaScript-compatibility mode). For example,
1090        /(another)?(\1?)test/ matched against "hello world test". This bug was
1091        introduced in release 8.13.
1093    6.  Add support for 16-bit character strings (a large amount of work involving
1094        many changes and refactorings).
1096    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1097        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1098        from a file.
1100    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1101        rounding is not applied in this particular case).
1103    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1104        if they appear, or are escaped, in patterns.
1106    10. Get rid of a number of -Wunused-but-set-variable warnings.
1108    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1109        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1110        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1111        also returns the mark "x". This bug applied to capturing parentheses,
1112        non-capturing parentheses, and atomic parentheses. It also applied to some
1113        assertions.
1115    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1116        information out of configure.ac instead of relying on pcre.h.generic, which
1117        is not stored in the repository.
1119    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1120        -lreadline.
1122    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1124    15. Applied Graycode's patch to put the top-level frame on the stack rather
1125        than the heap when not using the stack for recursion. This gives a
1126        performance improvement in many cases when recursion is not deep.
1128    16. Experimental code added to "pcretest -C" to output the stack frame size.
1131    Version 8.21 12-Dec-2011
1132    ------------------------
1134  1.  Updating the JIT compiler.  1.  Updating the JIT compiler.
1136    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1137        are added as well.
1139    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1140        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1141        calling _pcre_jit_exec. Some extra comments are added.
1143    4.  (*MARK) settings inside atomic groups that do not contain any capturing
1144        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1145        was introduced by change 18 for 8.20.
1147    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1148        ECMA-262 standard.
1150    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1151        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1152        This bug was probably introduced by change 9 of 8.13.
1154    7.  While fixing 6 above, I noticed that a number of other items were being
1155        incorrectly rejected as "not fixed length". This arose partly because newer
1156        opcodes had not been added to the fixed-length checking code. I have (a)
1157        corrected the bug and added tests for these items, and (b) arranged for an
1158        error to occur if an unknown opcode is encountered while checking for fixed
1159        length instead of just assuming "not fixed length". The items that were
1160        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1161        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1162        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1164    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1165        being incorrectly compiled and would have given unpredicatble results.
1167    9.  A possessively repeated subpattern with minimum repeat count greater than
1168        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1169        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1170        the first (A) could occur when it should not.
1172    10. Add a cast and remove a redundant test from the code.
1174    11. JIT should use pcre_malloc/pcre_free for allocation.
1176    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1177        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1178        is anything other than /usr, -L is still shown).
1180    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1182    14. Perl does not support \N without a following name in a [] class; PCRE now
1183        also gives an error.
1185    15. If a forward reference was repeated with an upper limit of around 2000,
1186        it caused the error "internal error: overran compiling workspace". The
1187        maximum number of forward references (including repeats) was limited by the
1188        internal workspace, and dependent on the LINK_SIZE. The code has been
1189        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1190        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1191        of around 200,000 forward references. While doing this, I also speeded up
1192        the filling in of repeated forward references.
1194    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1195        incorrectly expecting the subject to contain another "a" after the start.
1197    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1198        in the match, the SKIP should be ignored. This was not happening; instead
1199        the SKIP was being treated as NOMATCH. For patterns such as
1200        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1201        tested.
1203    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1204        now much more compatible with Perl, in particular in cases where the result
1205        is a non-match for a non-anchored pattern. For example, if
1206        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1207        "m", where previously it did not return a name. A side effect of this
1208        change is that for partial matches, the last encountered mark name is
1209        returned, as for non matches. A number of tests that were previously not
1210        Perl-compatible have been moved into the Perl-compatible test files. The
1211        refactoring has had the pleasing side effect of removing one argument from
1212        the match() function, thus reducing its stack requirements.
1214    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1215        subsequent uses of /S (without +) incorrectly behaved like /S+.
1217    21. Retrieve executable code size support for the JIT compiler and fixing
1218        some warnings.
1220    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1221        not work when the shorter character appeared right at the end of the
1222        subject string.
1224    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1225        systems.
1227    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1228        output it when the /M option is used in pcretest.
1230    25. The CheckMan script was not being included in the distribution. Also, added
1231        an explicit "perl" to run Perl scripts from the PrepareRelease script
1232        because this is reportedly needed in Windows.
1234    26. If study data was being save in a file and studying had not found a set of
1235        "starts with" bytes for the pattern, the data written to the file (though
1236        never used) was taken from uninitialized memory and so caused valgrind to
1237        complain.
1239    27. Updated RunTest.bat as provided by Sheri Pierce.
1241    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1243    29. Computation of memory usage for the table of capturing group names was
1244        giving an unnecessarily large value.
1247  Version 8.20 21-Oct-2011  Version 8.20 21-Oct-2011
1248  ------------------------  ------------------------
# Line 1021  Version 7.9 11-Apr-09 Line 2258  Version 7.9 11-Apr-09
2258  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
2259      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
2260      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2261      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2262        8.33.]
2264  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
2265      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 1264  Version 7.7 07-May-08 Line 2502  Version 7.7 07-May-08
2502      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2503      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2504      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2505      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2506      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2507      was subsequently set up correctly.)      was subsequently set up correctly.)

Removed from v.740  
changed lines
  Added in v.1545

  ViewVC Help
Powered by ViewVC 1.1.5