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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.13 02-Aug-2011  Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5    development is happening in the PCRE2 10.xx series.
7    Version 8.41
8    ------------
10    1.  Fixed typo in CMakeLists.txt (wrong number of arguments for
11    PCRE_STATIC_RUNTIME (affects MSVC only).
13    2.  Issue 1 for 8.40 below was not correctly fixed. If pcregrep in multiline
14    mode with --only-matching matched several lines, it restarted scanning at the
15    next line instead of moving on to the end of the matched string, which can be
16    several lines after the start.
18    3.  Fix a missing else in the JIT compiler reported by 'idaifish'.
20    4.  A (?# style comment is now ignored between a basic quantifier and a
21    following '+' or '?' (example: /X+(?#comment)?Y/.
23    5.  Avoid use of a potentially overflowing buffer in pcregrep (patch by Petr
24    Pisar).
26    6.  Fuzzers have reported issues in pcretest. These are NOT serious (it is,
27    after all, just a test program). However, to stop the reports, some easy ones
28    are fixed:
30        (a) Check for values < 256 when calling isprint() in pcretest.
31        (b) Give an error for too big a number after \O.
33    7.  In the 32-bit library in non-UTF mode, an attempt to find a Unicode
34    property for a character with a code point greater than 0x10ffff (the Unicode
35    maximum) caused a crash.
37    8. The alternative matching function, pcre_dfa_exec() misbehaved if it
38    encountered a character class with a possessive repeat, for example [a-f]{3}+.
40    9. When pcretest called pcre_copy_substring() in 32-bit mode, it set the buffer
41    length incorrectly, which could result in buffer overflow.
43    10. Remove redundant line of code (accidentally left in ages ago).
46    Version 8.40 11-January-2017
47    ----------------------------
49    1.  Using -o with -M in pcregrep could cause unnecessary repeated output when
50        the match extended over a line boundary.
52    2.  Applied Chris Wilson's second patch (Bugzilla #1681) to CMakeLists.txt for
53        MSVC static compilation, putting the first patch under a new option.
55    3.  Fix register overwite in JIT when SSE2 acceleration is enabled.
57    4.  Ignore "show all captures" (/=) for DFA matching.
59    5.  Fix JIT unaligned accesses on x86. Patch by Marc Mutz.
61    6.  In any wide-character mode (8-bit UTF or any 16-bit or 32-bit mode),
62        without PCRE_UCP set, a negative character type such as \D in a positive
63        class should cause all characters greater than 255 to match, whatever else
64        is in the class. There was a bug that caused this not to happen if a
65        Unicode property item was added to such a class, for example [\D\P{Nd}] or
66        [\W\pL].
68    7.  When pcretest was outputing information from a callout, the caret indicator
69        for the current position in the subject line was incorrect if it was after
70        an escape sequence for a character whose code point was greater than
71        \x{ff}.
73    8.  A pattern such as (?<RA>abc)(?(R)xyz) was incorrectly compiled such that
74        the conditional was interpreted as a reference to capturing group 1 instead
75        of a test for recursion. Any group whose name began with R was
76        misinterpreted in this way. (The reference interpretation should only
77        happen if the group's name is precisely "R".)
79    9.  A number of bugs have been mended relating to match start-up optimizations
80        when the first thing in a pattern is a positive lookahead. These all
81        applied only when PCRE_NO_START_OPTIMIZE was *not* set:
83        (a) A pattern such as (?=.*X)X$ was incorrectly optimized as if it needed
84            both an initial 'X' and a following 'X'.
85        (b) Some patterns starting with an assertion that started with .* were
86            incorrectly optimized as having to match at the start of the subject or
87            after a newline. There are cases where this is not true, for example,
88            (?=.*[A-Z])(?=.{8,16})(?!.*[\s]) matches after the start in lines that
89            start with spaces. Starting .* in an assertion is no longer taken as an
90            indication of matching at the start (or after a newline).
93    Version 8.39 14-June-2016
94    -------------------------
96    1.  If PCRE_AUTO_CALLOUT was set on a pattern that had a (?# comment between
97        an item and its qualifier (for example, A(?#comment)?B) pcre_compile()
98        misbehaved. This bug was found by the LLVM fuzzer.
100    2.  Similar to the above, if an isolated \E was present between an item and its
101        qualifier when PCRE_AUTO_CALLOUT was set, pcre_compile() misbehaved. This
102        bug was found by the LLVM fuzzer.
104    3.  Further to 8.38/46, negated classes such as [^[:^ascii:]\d] were also not
105        working correctly in UCP mode.
107    4.  The POSIX wrapper function regexec() crashed if the option REG_STARTEND
108        was set when the pmatch argument was NULL. It now returns REG_INVARG.
110    5.  Allow for up to 32-bit numbers in the ordin() function in pcregrep.
112    6.  An empty \Q\E sequence between an item and its qualifier caused
113        pcre_compile() to misbehave when auto callouts were enabled. This bug was
114        found by the LLVM fuzzer.
116    7.  If a pattern that was compiled with PCRE_EXTENDED started with white
117        space or a #-type comment that was followed by (?-x), which turns off
118        PCRE_EXTENDED, and there was no subsequent (?x) to turn it on again,
119        pcre_compile() assumed that (?-x) applied to the whole pattern and
120        consequently mis-compiled it. This bug was found by the LLVM fuzzer.
122    8.  A call of pcre_copy_named_substring() for a named substring whose number
123        was greater than the space in the ovector could cause a crash.
125    9.  Yet another buffer overflow bug involved duplicate named groups with a
126        group that reset capture numbers (compare 8.38/7 below). Once again, I have
127        just allowed for more memory, even if not needed. (A proper fix is
128        implemented in PCRE2, but it involves a lot of refactoring.)
130    10. pcre_get_substring_list() crashed if the use of \K in a match caused the
131        start of the match to be earlier than the end.
133    11. Migrating appropriate PCRE2 JIT improvements to PCRE.
135    12. A pattern such as /(?<=((?C)0))/, which has a callout inside a lookbehind
136        assertion, caused pcretest to generate incorrect output, and also to read
137        uninitialized memory (detected by ASAN or valgrind).
139    13. A pattern that included (*ACCEPT) in the middle of a sufficiently deeply
140        nested set of parentheses of sufficient size caused an overflow of the
141        compiling workspace (which was diagnosed, but of course is not desirable).
143    14. And yet another buffer overflow bug involving duplicate named groups, this
144        time nested, with a nested back reference. Yet again, I have just allowed
145        for more memory, because anything more needs all the refactoring that has
146        been done for PCRE2. An example pattern that provoked this bug is:
147        /((?J)(?'R'(?'R'(?'R'(?'R'(?'R'(?|(\k'R'))))))))/ and the bug was
148        registered as CVE-2016-1283.
150    15. pcretest went into a loop if global matching was requested with an ovector
151        size less than 2. It now gives an error message. This bug was found by
152        afl-fuzz.
154    16. An invalid pattern fragment such as (?(?C)0 was not diagnosing an error
155        ("assertion expected") when (?(?C) was not followed by an opening
156        parenthesis.
158    17. Fixed typo ("&&" for "&") in pcre_study(). Fortunately, this could not
159        actually affect anything, by sheer luck.
161    18. Applied Chris Wilson's patch (Bugzilla #1681) to CMakeLists.txt for MSVC
162        static compilation.
164    19. Modified the RunTest script to incorporate a valgrind suppressions file so
165        that certain errors, provoked by the SSE2 instruction set when JIT is used,
166        are ignored.
168    20. A racing condition is fixed in JIT reported by Mozilla.
170    21. Minor code refactor to avoid "array subscript is below array bounds"
171        compiler warning.
173    22. Minor code refactor to avoid "left shift of negative number" warning.
175    23. Fix typo causing compile error when 16- or 32-bit JIT is compiled without
176        UCP support.
178    24. Refactor to avoid compiler warnings in pcrecpp.cc.
180    25. Refactor to fix a typo in pcre_jit_test.c
182    26. Patch to support compiling pcrecpp.cc with Intel compiler.
185    Version 8.38 23-November-2015
186    -----------------------------
188    1.  If a group that contained a recursive back reference also contained a
189        forward reference subroutine call followed by a non-forward-reference
190        subroutine call, for example /.((?2)(?R)\1)()/, pcre_compile() failed to
191        compile correct code, leading to undefined behaviour or an internally
192        detected error. This bug was discovered by the LLVM fuzzer.
194    2.  Quantification of certain items (e.g. atomic back references) could cause
195        incorrect code to be compiled when recursive forward references were
196        involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
197        This bug was discovered by the LLVM fuzzer.
199    3.  A repeated conditional group whose condition was a reference by name caused
200        a buffer overflow if there was more than one group with the given name.
201        This bug was discovered by the LLVM fuzzer.
203    4.  A recursive back reference by name within a group that had the same name as
204        another group caused a buffer overflow. For example:
205        /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
207    5.  A forward reference by name to a group whose number is the same as the
208        current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
209        a buffer overflow at compile time. This bug was discovered by the LLVM
210        fuzzer.
212    6.  A lookbehind assertion within a set of mutually recursive subpatterns could
213        provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
215    7.  Another buffer overflow bug involved duplicate named groups with a
216        reference between their definition, with a group that reset capture
217        numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
218        fixed by always allowing for more memory, even if not needed. (A proper fix
219        is implemented in PCRE2, but it involves more refactoring.)
221    8.  There was no check for integer overflow in subroutine calls such as (?123).
223    9.  The table entry for \l in EBCDIC environments was incorrect, leading to its
224        being treated as a literal 'l' instead of causing an error.
226    10. There was a buffer overflow if pcre_exec() was called with an ovector of
227        size 1. This bug was found by american fuzzy lop.
229    11. If a non-capturing group containing a conditional group that could match
230        an empty string was repeated, it was not identified as matching an empty
231        string itself. For example: /^(?:(?(1)x|)+)+$()/.
233    12. In an EBCDIC environment, pcretest was mishandling the escape sequences
234        \a and \e in test subject lines.
236    13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
237        instead of the EBCDIC value.
239    14. The handling of \c in an EBCDIC environment has been revised so that it is
240        now compatible with the specification in Perl's perlebcdic page.
242    15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
243        ASCII/Unicode. This has now been added to the list of characters that are
244        recognized as white space in EBCDIC.
246    16. When PCRE was compiled without UCP support, the use of \p and \P gave an
247        error (correctly) when used outside a class, but did not give an error
248        within a class.
250    17. \h within a class was incorrectly compiled in EBCDIC environments.
252    18. A pattern with an unmatched closing parenthesis that contained a backward
253        assertion which itself contained a forward reference caused buffer
254        overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
256    19. JIT should return with error when the compiled pattern requires more stack
257        space than the maximum.
259    20. A possessively repeated conditional group that could match an empty string,
260        for example, /(?(R))*+/, was incorrectly compiled.
262    21. Fix infinite recursion in the JIT compiler when certain patterns such as
263        /(?:|a|){100}x/ are analysed.
265    22. Some patterns with character classes involving [: and \\ were incorrectly
266        compiled and could cause reading from uninitialized memory or an incorrect
267        error diagnosis.
269    23. Pathological patterns containing many nested occurrences of [: caused
270        pcre_compile() to run for a very long time.
272    24. A conditional group with only one branch has an implicit empty alternative
273        branch and must therefore be treated as potentially matching an empty
274        string.
276    25. If (?R was followed by - or + incorrect behaviour happened instead of a
277        diagnostic.
279    26. Arrange to give up on finding the minimum matching length for overly
280        complex patterns.
282    27. Similar to (4) above: in a pattern with duplicated named groups and an
283        occurrence of (?| it is possible for an apparently non-recursive back
284        reference to become recursive if a later named group with the relevant
285        number is encountered. This could lead to a buffer overflow. Wen Guanxing
286        from Venustech ADLAB discovered this bug.
288    28. If pcregrep was given the -q option with -c or -l, or when handling a
289        binary file, it incorrectly wrote output to stdout.
291    29. The JIT compiler did not restore the control verb head in case of *THEN
292        control verbs. This issue was found by Karl Skomski with a custom LLVM
293        fuzzer.
295    30. Error messages for syntax errors following \g and \k were giving inaccurate
296        offsets in the pattern.
298    31. Added a check for integer overflow in conditions (?(<digits>) and
299        (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
300        fuzzer.
302    32. Handling recursive references such as (?2) when the reference is to a group
303        later in the pattern uses code that is very hacked about and error-prone.
304        It has been re-written for PCRE2. Here in PCRE1, a check has been added to
305        give an internal error if it is obvious that compiling has gone wrong.
307    33. The JIT compiler should not check repeats after a {0,1} repeat byte code.
308        This issue was found by Karl Skomski with a custom LLVM fuzzer.
310    34. The JIT compiler should restore the control chain for empty possessive
311        repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer.
313    35. Match limit check added to JIT recursion. This issue was found by Karl
314        Skomski with a custom LLVM fuzzer.
316    36. Yet another case similar to 27 above has been circumvented by an
317        unconditional allocation of extra memory. This issue is fixed "properly" in
318        PCRE2 by refactoring the way references are handled. Wen Guanxing
319        from Venustech ADLAB discovered this bug.
321    37. Fix two assertion fails in JIT. These issues were found by Karl Skomski
322        with a custom LLVM fuzzer.
324    38. Fixed a corner case of range optimization in JIT.
326    39. An incorrect error "overran compiling workspace" was given if there were
327        exactly enough group forward references such that the last one extended
328        into the workspace safety margin. The next one would have expanded the
329        workspace. The test for overflow was not including the safety margin.
331    40. A match limit issue is fixed in JIT which was found by Karl Skomski
332        with a custom LLVM fuzzer.
334    41. Remove the use of /dev/null in testdata/testinput2, because it doesn't
335        work under Windows. (Why has it taken so long for anyone to notice?)
337    42. In a character class such as [\W\p{Any}] where both a negative-type escape
338        ("not a word character") and a property escape were present, the property
339        escape was being ignored.
341    43. Fix crash caused by very long (*MARK) or (*THEN) names.
343    44. A sequence such as [[:punct:]b] that is, a POSIX character class followed
344        by a single ASCII character in a class item, was incorrectly compiled in
345        UCP mode. The POSIX class got lost, but only if the single character
346        followed it.
348    45. [:punct:] in UCP mode was matching some characters in the range 128-255
349        that should not have been matched.
351    46. If [:^ascii:] or [:^xdigit:] or [:^cntrl:] are present in a non-negated
352        class, all characters with code points greater than 255 are in the class.
353        When a Unicode property was also in the class (if PCRE_UCP is set, escapes
354        such as \w are turned into Unicode properties), wide characters were not
355        correctly handled, and could fail to match.
358    Version 8.37 28-April-2015
359    --------------------------
361    1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
362        for those parentheses to be closed with whatever has been captured so far.
363        However, it was failing to mark any other groups between the hightest
364        capture so far and the currrent group as "unset". Thus, the ovector for
365        those groups contained whatever was previously there. An example is the
366        pattern /(x)|((*ACCEPT))/ when matched against "abcd".
368    2.  If an assertion condition was quantified with a minimum of zero (an odd
369        thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
371    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
372        unrecognized modifier, a crash could occur.
374    4.  An attempt to do global matching in pcretest with a zero-length ovector
375        caused a crash.
377    5.  Fixed a memory leak during matching that could occur for a subpattern
378        subroutine call (recursive or otherwise) if the number of captured groups
379        that had to be saved was greater than ten.
381    6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
382        string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
383        UTF with NO_UTF_CHECK is documented as having an undefined outcome.
385    7.  A UTF pattern containing a "not" match of a non-ASCII character and a
386        subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
388    8. When a pattern is compiled, it remembers the highest back reference so that
389       when matching, if the ovector is too small, extra memory can be obtained to
390       use instead. A conditional subpattern whose condition is a check on a
391       capture having happened, such as, for example in the pattern
392       /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
393       setting the highest backreference number. This mattered only if pcre_exec()
394       was called with an ovector that was too small to hold the capture, and there
395       was no other kind of back reference (a situation which is probably quite
396       rare). The effect of the bug was that the condition was always treated as
397       FALSE when the capture could not be consulted, leading to a incorrect
398       behaviour by pcre_exec(). This bug has been fixed.
400    9. A reference to a duplicated named group (either a back reference or a test
401       for being set in a conditional) that occurred in a part of the pattern where
402       PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
403       to be incorrectly calculated, leading to overwriting.
405    10. A mutually recursive set of back references such as (\2)(\1) caused a
406        segfault at study time (while trying to find the minimum matching length).
407        The infinite loop is now broken (with the minimum length unset, that is,
408        zero).
410    11. If an assertion that was used as a condition was quantified with a minimum
411        of zero, matching went wrong. In particular, if the whole group had
412        unlimited repetition and could match an empty string, a segfault was
413        likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
414        assertions to be quantified, but not if they are being used as conditions,
415        so the above pattern is faulted by Perl. PCRE has now been changed so that
416        it also rejects such patterns.
418    12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
419        failed to allow the zero-repeat case if pcre2_exec() was called with an
420        ovector too small to capture the group.
422    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
423        Red Hat Product Security:
425        (a) A crash if /K and /F were both set with the option to save the compiled
426        pattern.
428        (b) Another crash if the option to print captured substrings in a callout
429        was combined with setting a null ovector, for example \O\C+ as a subject
430        string.
432    14. A pattern such as "((?2){0,1999}())?", which has a group containing a
433        forward reference repeated a large (but limited) number of times within a
434        repeated outer group that has a zero minimum quantifier, caused incorrect
435        code to be compiled, leading to the error "internal error:
436        previously-checked referenced subpattern not found" when an incorrect
437        memory address was read. This bug was reported as "heap overflow",
438        discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
439        CVE-2015-2325.
441    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
442        call within a group that also contained a recursive back reference caused
443        incorrect code to be compiled. This bug was reported as "heap overflow",
444        discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
445        number CVE-2015-2326.
447    24. Computing the size of the JIT read-only data in advance has been a source
448        of various issues, and new ones are still appear unfortunately. To fix
449        existing and future issues, size computation is eliminated from the code,
450        and replaced by on-demand memory allocation.
452    25. A pattern such as /(?i)[A-`]/, where characters in the other case are
453        adjacent to the end of the range, and the range contained characters with
454        more than one other case, caused incorrect behaviour when compiled in UTF
455        mode. In that example, the range a-j was left out of the class.
457    26. Fix JIT compilation of conditional blocks, which assertion
458        is converted to (*FAIL). E.g: /(?(?!))/.
460    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
461        discovered by the LLVM fuzzer.
463    28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
464        when this assertion was used as a condition, for example (?(?!)a|b). In
465        pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
466        error about an unsupported item.
468    29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
469        possessification code could take exponential time to complete. A recursion
470        depth limit of 1000 has been imposed to limit the resources used by this
471        optimization.
473    30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
474        such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
475        because \S ensures they are all in the class. The code for doing this was
476        interacting badly with the code for computing the amount of space needed to
477        compile the pattern, leading to a buffer overflow. This bug was discovered
478        by the LLVM fuzzer.
480    31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
481        other kinds of group caused stack overflow at compile time. This bug was
482        discovered by the LLVM fuzzer.
484    32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
485        between a subroutine call and its quantifier was incorrectly compiled,
486        leading to buffer overflow or other errors. This bug was discovered by the
487        LLVM fuzzer.
489    33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
490        assertion after (?(. The code was failing to check the character after
491        (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
492        was discovered by the LLVM fuzzer.
494    34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
495        a fixed maximum following a group that contains a subroutine reference was
496        incorrectly compiled and could trigger buffer overflow. This bug was
497        discovered by the LLVM fuzzer.
499    35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
500        caused a stack overflow instead of the diagnosis of a non-fixed length
501        lookbehind assertion. This bug was discovered by the LLVM fuzzer.
503    36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
504        (e.g. /(?<=\Ka)/) could make pcregrep loop.
506    37. There was a similar problem to 36 in pcretest for global matches.
508    38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
509        and a subsequent item in the pattern caused a non-match, backtracking over
510        the repeated \X did not stop, but carried on past the start of the subject,
511        causing reference to random memory and/or a segfault. There were also some
512        other cases where backtracking after \C could crash. This set of bugs was
513        discovered by the LLVM fuzzer.
515    39. The function for finding the minimum length of a matching string could take
516        a very long time if mutual recursion was present many times in a pattern,
517        for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
518        method has been implemented. This infelicity was discovered by the LLVM
519        fuzzer.
521    40. Static linking against the PCRE library using the pkg-config module was
522        failing on missing pthread symbols.
525    Version 8.36 26-September-2014
526    ------------------------------
528    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
529        -Wmissing-field-initializers and -Wunused-parameter.
531    2.  The tests for quantifiers being too big (greater than 65535) were being
532        applied after reading the number, and stupidly assuming that integer
533        overflow would give a negative number. The tests are now applied as the
534        numbers are read.
536    3.  Tidy code in pcre_exec.c where two branches that used to be different are
537        now the same.
539    4.  The JIT compiler did not generate match limit checks for certain
540        bracketed expressions with quantifiers. This may lead to exponential
541        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
542        issue should be resolved now.
544    5.  Fixed an issue, which occures when nested alternatives are optimized
545        with table jumps.
547    6.  Inserted two casts and changed some ints to size_t in the light of some
548        reported 64-bit compiler warnings (Bugzilla 1477).
550    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
551        an empty string, which sometimes were behaving incorrectly in the
552        interpreter (though correctly in the JIT matcher). This pcretest input is
553        an example:
555          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
558        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
559        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
560        for an empty string was breaking the inner loop and carrying on at a lower
561        level, when possessive repeated groups should always return to a higher
562        level as they have no backtrack points in them. The empty string test now
563        occurs at the outer level.
565    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
566        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
568    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
569        doesn't).
571    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
572        to hold a pattern to be incorrectly computed (too small) when there were
573        named back references to duplicated names. This could cause "internal
574        error: code overflow" or "double free or corruption" or other memory
575        handling errors.
577    11. When named subpatterns had the same prefixes, back references could be
578        confused. For example, in this pattern:
580          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
582        the reference to 'Name' was incorrectly treated as a reference to a
583        duplicate name.
585    12. A pattern such as /^s?c/mi8 where the optional character has more than
586        one "other case" was incorrectly compiled such that it would only try to
587        match starting at "c".
589    13. When a pattern starting with \s was studied, VT was not included in the
590        list of possible starting characters; this should have been part of the
591        8.34/18 patch.
593    14. If a character class started [\Qx]... where x is any character, the class
594        was incorrectly terminated at the ].
596    15. If a pattern that started with a caseless match for a character with more
597        than one "other case" was studied, PCRE did not set up the starting code
598        unit bit map for the list of possible characters. Now it does. This is an
599        optimization improvement, not a bug fix.
601    16. The Unicode data tables have been updated to Unicode 7.0.0.
603    17. Fixed a number of memory leaks in pcregrep.
605    18. Avoid a compiler warning (from some compilers) for a function call with
606        a cast that removes "const" from an lvalue by using an intermediate
607        variable (to which the compiler does not object).
609    19. Incorrect code was compiled if a group that contained an internal recursive
610        back reference was optional (had quantifier with a minimum of zero). This
611        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
612        caused segmentation faults because of stack overflows at compile time.
614    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
615        group that is quantified with an indefinite repeat, caused a compile-time
616        loop which used up all the system stack and provoked a segmentation fault.
617        This was not the same bug as 19 above.
619    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
620        Patch by Mike Frysinger.
623    Version 8.35 04-April-2014
624    --------------------------
626    1.  A new flag is set, when property checks are present in an XCLASS.
627        When this flag is not set, PCRE can perform certain optimizations
628        such as studying these XCLASS-es.
630    2.  The auto-possessification of character sets were improved: a normal
631        and an extended character set can be compared now. Furthermore
632        the JIT compiler optimizes more character set checks.
634    3.  Got rid of some compiler warnings for potentially uninitialized variables
635        that show up only when compiled with -O2.
637    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
638        of a match later then the end of the match. The pcretest program was not
639        handling the case sensibly - it was outputting from the start to the next
640        binary zero. It now reports this situation in a message, and outputs the
641        text from the end to the start.
643    5.  Fast forward search is improved in JIT. Instead of the first three
644        characters, any three characters with fixed position can be searched.
645        Search order: first, last, middle.
647    6.  Improve character range checks in JIT. Characters are read by an inprecise
648        function now, which returns with an unknown value if the character code is
649        above a certain threshold (e.g: 256). The only limitation is that the value
650        must be bigger than the threshold as well. This function is useful when
651        the characters above the threshold are handled in the same way.
653    7.  The macros whose names start with RAWUCHAR are placeholders for a future
654        mode in which only the bottom 21 bits of 32-bit data items are used. To
655        make this more memorable for those maintaining the code, the names have
656        been changed to start with UCHAR21, and an extensive comment has been added
657        to their definition.
659    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
660        to the export list in Makefile.am (they were accidentally omitted from the
661        8.34 tarball).
663    9.  The informational output from pcretest used the phrase "starting byte set"
664        which is inappropriate for the 16-bit and 32-bit libraries. As the output
665        for "first char" and "need char" really means "non-UTF-char", I've changed
666        "byte" to "char", and slightly reworded the output. The documentation about
667        these values has also been (I hope) clarified.
669    10. Another JIT related optimization: use table jumps for selecting the correct
670        backtracking path, when more than four alternatives are present inside a
671        bracket.
673    11. Empty match is not possible, when the minimum length is greater than zero,
674        and there is no \K in the pattern. JIT should avoid empty match checks in
675        such cases.
677    12. In a caseless character class with UCP support, when a character with more
678        than one alternative case was not the first character of a range, not all
679        the alternative cases were added to the class. For example, s and \x{17f}
680        are both alternative cases for S: the class [RST] was handled correctly,
681        but [R-T] was not.
683    13. The configure.ac file always checked for pthread support when JIT was
684        enabled. This is not used in Windows, so I have put this test inside a
685        check for the presence of windows.h (which was already tested for).
687    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
688        The algorithm provides a way to skip certain starting offsets, and usually
689        faster than linear prefix searches.
691    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
692        as for 'fr_FR' and 'french'. For some reason, however, it then used the
693        Windows-specific input and output files, which have 'french' screwed in.
694        So this could never have worked. One of the problems with locales is that
695        they aren't always the same. I have now updated RunTest so that it checks
696        the output of the locale test (test 3) against three different output
697        files, and it allows the test to pass if any one of them matches. With luck
698        this should make the test pass on some versions of Solaris where it was
699        failing. Because of the uncertainty, the script did not used to stop if
700        test 3 failed; it now does. If further versions of a French locale ever
701        come to light, they can now easily be added.
703    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
704        there was a message during ./configure, but it did not stop. This now
705        provokes an error. The invalid example in README has been corrected.
706        If a value less than the minimum is given, the minimum value has always
707        been used, but now a warning is given.
709    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
710        was a bug in the test system, which is now fixed. Also, the list of various
711        configurations that are tested for each release did not have one with both
712        16/32 bits and --enable-bar-anycrlf. It now does.
714    18. pcretest was missing "-C bsr" for displaying the \R default setting.
716    19. Little endian PowerPC systems are supported now by the JIT compiler.
718    20. The fast forward newline mechanism could enter to an infinite loop on
719        certain invalid UTF-8 input. Although we don't support these cases
720        this issue can be fixed by a performance optimization.
722    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
723        not take account if existing stack usage. There is now a new global
724        variable called pcre_stack_guard that can be set to point to an external
725        function to check stack availability. It is called at the start of
726        processing every parenthesized group.
728    22. A typo in the code meant that in ungreedy mode the max/min qualifier
729        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
730        not match "ab".
732    23. When UTF was disabled, the JIT program reported some incorrect compile
733        errors. These messages are silenced now.
735    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
736        compiler.
738    25. Change all the temporary files used in RunGrepTest to be different to those
739        used by RunTest so that the tests can be run simultaneously, for example by
740        "make -j check".
743    Version 8.34 15-December-2013
744    -----------------------------
746    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
747        executable memory. Patch inspired by Carsten Klein.
749    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
750        this macro is never tested and has no effect, because the work to support
751        coverage involves only compiling and linking options and special targets in
752        the Makefile. The comment in config.h implied that defining the macro would
753        enable coverage support, which is totally false. There was also support for
754        setting this macro in the CMake files (my fault, I just copied it from
755        configure). SUPPORT_GCOV has now been removed.
757    3.  Make a small performance improvement in strlen16() and strlen32() in
758        pcretest.
760    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
761        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
762        these cases). There was also one in pcretest.c.
764    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
766    6.  In UTF mode, the code for checking whether a group could match an empty
767        string (which is used for indefinitely repeated groups to allow for
768        breaking an infinite loop) was broken when the group contained a repeated
769        negated single-character class with a character that occupied more than one
770        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
771        UTF-8 mode). The effect was undefined: the group might or might not be
772        deemed as matching an empty string, or the program might have crashed.
774    7.  The code for checking whether a group could match an empty string was not
775        recognizing that \h, \H, \v, \V, and \R must match a character.
777    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
778        an empty string. If it can, pcretest shows this in its information output.
780    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
781        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
782        matched by pcre_exec() without using JIT:
784        (a) If the rest of the pattern did not match after a maximal run of
785            grapheme clusters, the code for backing up to try with fewer of them
786            did not always back up over a full grapheme when characters that do not
787            have the modifier quality were involved, e.g. Hangul syllables.
789        (b) If the match point in a subject started with modifier character, and
790            there was no match, the code could incorrectly back up beyond the match
791            point, and potentially beyond the first character in the subject,
792            leading to a segfault or an incorrect match result.
794    10. A conditional group with an assertion condition could lead to PCRE
795        recording an incorrect first data item for a match if no other first data
796        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
797        first data item, and therefore matched "ca" after "c" instead of at the
798        start.
800    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
801        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
803    12. The source of pcregrep now includes z/OS-specific code so that it can be
804        compiled for z/OS as part of the special z/OS distribution.
806    13. Added the -T and -TM options to pcretest.
808    14. The code in pcre_compile.c for creating the table of named capturing groups
809        has been refactored. Instead of creating the table dynamically during the
810        actual compiling pass, the information is remembered during the pre-compile
811        pass (on the stack unless there are more than 20 named groups, in which
812        case malloc() is used) and the whole table is created before the actual
813        compile happens. This has simplified the code (it is now nearly 150 lines
814        shorter) and prepared the way for better handling of references to groups
815        with duplicate names.
817    15. A back reference to a named subpattern when there is more than one of the
818        same name now checks them in the order in which they appear in the pattern.
819        The first one that is set is used for the reference. Previously only the
820        first one was inspected. This change makes PCRE more compatible with Perl.
822    16. Unicode character properties were updated from Unicode 6.3.0.
824    17. The compile-time code for auto-possessification has been refactored, based
825        on a patch by Zoltan Herczeg. It now happens after instead of during
826        compilation. The code is cleaner, and more cases are handled. The option
827        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
828        options in pcretest are provided to set it. It can also be set by
829        (*NO_AUTO_POSSESS) at the start of a pattern.
831    18. The character VT has been added to the default ("C" locale) set of
832        characters that match \s and are generally treated as white space,
833        following this same change in Perl 5.18. There is now no difference between
834        "Perl space" and "POSIX space". Whether VT is treated as white space in
835        other locales depends on the locale.
837    19. The code for checking named groups as conditions, either for being set or
838        for being recursed, has been refactored (this is related to 14 and 15
839        above). Processing unduplicated named groups should now be as fast at
840        numerical groups, and processing duplicated groups should be faster than
841        before.
843    20. Two patches to the CMake build system, by Alexander Barkov:
845          (1) Replace the "source" command by "." in CMakeLists.txt because
846              "source" is a bash-ism.
848          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
849              without these the CMake build does not work on Solaris.
851    21. Perl has changed its handling of \8 and \9. If there is no previously
852        encountered capturing group of those numbers, they are treated as the
853        literal characters 8 and 9 instead of a binary zero followed by the
854        literals. PCRE now does the same.
856    22. Following Perl, added \o{} to specify codepoints in octal, making it
857        possible to specify values greater than 0777 and also making them
858        unambiguous.
860    23. Perl now gives an error for missing closing braces after \x{... instead of
861        treating the string as literal. PCRE now does the same.
863    24. RunTest used to grumble if an inappropriate test was selected explicitly,
864        but just skip it when running all tests. This make it awkward to run ranges
865        of tests when one of them was inappropriate. Now it just skips any
866        inappropriate tests, as it always did when running all tests.
868    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
869        character types such as \d or \w, too many callouts were inserted, and the
870        data that they returned was rubbish.
872    26. In UCP mode, \s was not matching two of the characters that Perl matches,
873        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
874        were matched by \h. The code has now been refactored so that the lists of
875        the horizontal and vertical whitespace characters used for \h and \v (which
876        are defined only in one place) are now also used for \s.
878    27. Add JIT support for the 64 bit TileGX architecture.
879        Patch by Jiong Wang (Tilera Corporation).
881    28. Possessive quantifiers for classes (both explicit and automatically
882        generated) now use special opcodes instead of wrapping in ONCE brackets.
884    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
885        (because it's meaningless), this was not happening when PCRE_CASELESS was
886        set. Not wrong, but inefficient.
888    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
889        properties for \w, \d, etc) is present in a test regex. Otherwise if the
890        test contains no characters greater than 255, Perl doesn't realise it
891        should be using Unicode semantics.
893    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
894        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
895        does in Unicode mode.
897    32. Added the "forbid" facility to pcretest so that putting tests into the
898        wrong test files can sometimes be quickly detected.
900    33. There is now a limit (default 250) on the depth of nesting of parentheses.
901        This limit is imposed to control the amount of system stack used at compile
902        time. It can be changed at build time by --with-parens-nest-limit=xxx or
903        the equivalent in CMake.
905    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
906        errors. Perl warns for these when in warning mode, but PCRE has no facility
907        for giving warnings.
909    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
910        However, this was not working for (?!) because it is optimized to (*FAIL),
911        for which PCRE does not allow quantifiers. The optimization is now disabled
912        when a quantifier follows (?!). I can't see any use for this, but it makes
913        things uniform.
915    36. Perl no longer allows group names to start with digits, so I have made this
916        change also in PCRE. It simplifies the code a bit.
918    37. In extended mode, Perl ignores spaces before a + that indicates a
919        possessive quantifier. PCRE allowed a space before the quantifier, but not
920        before the possessive +. It now does.
922    38. The use of \K (reset reported match start) within a repeated possessive
923        group such as (a\Kb)*+ was not working.
925    40. Document that the same character tables must be used at compile time and
926        run time, and that the facility to pass tables to pcre_exec() and
927        pcre_dfa_exec() is for use only with saved/restored patterns.
929    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
930        features for Builds with MSVC:
932        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
933           builds). The .rc files can be used to set FileDescription and many other
934           attributes.
936        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
937           This allows higher-level build scripts which want .pdb files to avoid
938           hard-coding the exact files needed."
940    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
941        mean "start of word" and "end of word", respectively, as a transition aid.
943    43. A minimizing repeat of a class containing codepoints greater than 255 in
944        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
945        compiled to use the heap for recursion.
947    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
948        is configured.
951    Version 8.33 28-May-2013
952    ------------------------
954    1.  Added 'U' to some constants that are compared to unsigned integers, to
955        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
956        variables that are added to signed variables, to ensure the result is
957        signed and can be negated.
959    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
960        CMake config files.
962    3.  Revise the creation of config.h.generic so that all boolean macros are
963        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
964        overriding via -D on the command line possible.
966    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
967        to unsigned int is reported to make a quite noticeable speed difference in
968        a specific Windows environment. Testing on Linux did also appear to show
969        some benefit (and it is clearly not harmful). Also fixed the definition of
970        Xop which should be unsigned.
972    5.  Related to (4), changing the definition of the intermediate variable cc
973        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
974        improvements.
976    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
977        unnecessary spaces.
979    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
980        and later.
982    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
984    9.  Optimizing fast_forward_start_bits in JIT.
986    10. Adding support for callouts in JIT, and fixing some issues revealed
987        during this work. Namely:
989        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
991        (b) Minimum length was not checked before the matching is started.
993    11. The value of capture_last that is passed to callouts was incorrect in some
994        cases when there was a capture on one path that was subsequently abandoned
995        after a backtrack. Also, the capture_last value is now reset after a
996        recursion, since all captures are also reset in this case.
998    12. The interpreter no longer returns the "too many substrings" error in the
999        case when an overflowing capture is in a branch that is subsequently
1000        abandoned after a backtrack.
1002    13. In the pathological case when an offset vector of size 2 is used, pcretest
1003        now prints out the matched string after a yield of 0 or 1.
1005    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
1006        Only supported by the JIT compiler at the moment.
1008    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
1010    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
1011        offset of the starting point of the matching process, provided the offsets
1012        vector is large enough.
1014    17. The \A escape now records a lookbehind value of 1, though its execution
1015        does not actually inspect the previous character. This is to ensure that,
1016        in partial multi-segment matching, at least one character from the old
1017        segment is retained when a new segment is processed. Otherwise, if there
1018        are no lookbehinds in the pattern, \A might match incorrectly at the start
1019        of a new segment.
1021    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
1023    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
1024        gives some modest performance improvement in 8-bit mode.
1026    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
1027        be expressed in certain programming languages using Universal Character
1028        Names.
1030    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
1031        which points out that "non characters" are not "characters that may not
1032        appear in Unicode strings" but rather "characters that are reserved for
1033        internal use and have only local meaning".
1035    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
1036        there was a conditional group that depended on an assertion, if the
1037        assertion was false, the callout that immediately followed the alternation
1038        in the condition was skipped when pcre_exec() was used for matching.
1040    23. Allow an explicit callout to be inserted before an assertion that is the
1041        condition for a conditional group, for compatibility with automatic
1042        callouts, which always insert a callout at this point.
1044    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
1045        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
1047    25. (*PRUNE) is now supported by the JIT compiler.
1049    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
1051    27. Fix the case where there are two or more SKIPs with arguments that may be
1052        ignored.
1054    28. (*SKIP) is now supported by the JIT compiler.
1056    29. (*THEN) is now supported by the JIT compiler.
1058    30. Update RunTest with additional test selector options.
1060    31. The way PCRE handles backtracking verbs has been changed in two ways.
1062        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
1063        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
1064        backtracking. In some cases this makes it more Perl-compatible, but Perl's
1065        rather obscure rules do not always do the same thing.
1067        (2) Previously, backtracking verbs were confined within assertions. This is
1068        no longer the case for positive assertions, except for (*ACCEPT). Again,
1069        this sometimes improves Perl compatibility, and sometimes does not.
1071    32. A number of tests that were in test 2 because Perl did things differently
1072        have been moved to test 1, because either Perl or PCRE has changed, and
1073        these tests are now compatible.
1075    32. Backtracking control verbs are now handled in the same way in JIT and
1076        interpreter.
1078    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
1079        contained a forward subroutine reference caused a compile error.
1081    34. Auto-detect and optimize limited repetitions in JIT.
1083    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
1084        blocking (*UTF) etc.
1086    36. In the interpreter, maximizing pattern repetitions for characters and
1087        character types now use tail recursion, which reduces stack usage.
1089    37. The value of the max lookbehind was not correctly preserved if a compiled
1090        and saved regex was reloaded on a host of different endianness.
1092    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
1093        of the compiled pattern block, expand the flags field from 16 to 32 bits
1094        because it was almost full.
1096    39. Try madvise first before posix_madvise.
1098    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
1099        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
1100        original change locked out all matches of empty strings. This has been
1101        changed so that one match of an empty string per line is recognized.
1102        Subsequent searches on the same line (for colouring or for --only-matching,
1103        for example) do not recognize empty strings.
1105    41. Applied a user patch to fix a number of spelling mistakes in comments.
1107    42. Data lines longer than 65536 caused pcretest to crash.
1109    43. Clarified the data type for length and startoffset arguments for pcre_exec
1110        and pcre_dfa_exec in the function-specific man pages, where they were
1111        explicitly stated to be in bytes, never having been updated. I also added
1112        some clarification to the pcreapi man page.
1114    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
1115        a segmentation fault.
1118    Version 8.32 30-November-2012
1119    -----------------------------
1121    1.  Improved JIT compiler optimizations for first character search and single
1122        character iterators.
1124    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
1125        Patch by Daniel Richard G.
1127    3.  Single character iterator optimizations in the JIT compiler.
1129    4.  Improved JIT compiler optimizations for character ranges.
1131    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
1132        Reported by Giuseppe D'Angelo.
1134    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
1135        of a line, was being set incorrectly in cases where .* appeared inside
1136        atomic brackets at the start of a pattern, or where there was a subsequent
1137        *PRUNE or *SKIP.
1139    7.  Improved instruction cache flush for POWER/PowerPC.
1140        Patch by Daniel Richard G.
1142    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
1143        grep:
1145        (a) There is now no limit to the number of patterns to be matched.
1147        (b) An error is given if a pattern is too long.
1149        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
1150            are now supported.
1152        (d) --exclude-from and --include-from (multiple use) have been added.
1154        (e) Exclusions and inclusions now apply to all files and directories, not
1155            just to those obtained from scanning a directory recursively.
1157        (f) Multiple uses of -f and --file-list are now supported.
1159        (g) In a Windows environment, the default for -d has been changed from
1160            "read" (the GNU grep default) to "skip", because otherwise the presence
1161            of a directory in the file list provokes an error.
1163        (h) The documentation has been revised and clarified in places.
1165    9.  Improve the matching speed of capturing brackets.
1167    10. Changed the meaning of \X so that it now matches a Unicode extended
1168        grapheme cluster.
1170    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
1171        out POSIX threads when JIT support is configured.
1173    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
1175    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
1176        structure could go wrong in environments where size_t is not the same size
1177        as int.
1179    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
1180        set.
1182    15. The EBCDIC support had decayed; later updates to the code had included
1183        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
1184        general tidy up of EBCDIC-related issues, and the documentation was also
1185        not quite right. There is now a test that can be run on ASCII systems to
1186        check some of the EBCDIC-related things (but is it not a full test).
1188    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
1189        in a small tidy to the code.
1191    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
1193    18. If the --only-matching (-o) option in pcregrep is specified multiple
1194        times, each one causes appropriate output. For example, -o1 -o2 outputs the
1195        substrings matched by the 1st and 2nd capturing parentheses. A separating
1196        string can be specified by --om-separator (default empty).
1198    19. Improving the first n character searches.
1200    20. Turn case lists for horizontal and vertical white space into macros so that
1201        they are defined only once.
1203    21. This set of changes together give more compatible Unicode case-folding
1204        behaviour for characters that have more than one other case when UCP
1205        support is available.
1207        (a) The Unicode property table now has offsets into a new table of sets of
1208            three or more characters that are case-equivalent. The MultiStage2.py
1209            script that generates these tables (the pcre_ucd.c file) now scans
1210            CaseFolding.txt instead of UnicodeData.txt for character case
1211            information.
1213        (b) The code for adding characters or ranges of characters to a character
1214            class has been abstracted into a generalized function that also handles
1215            case-independence. In UTF-mode with UCP support, this uses the new data
1216            to handle characters with more than one other case.
1218        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
1219            whose other case is greater than 256 are now correctly matched
1220            caselessly. Previously, the high codepoint matched the low one, but not
1221            vice versa.
1223        (d) The processing of \h, \H, \v, and \ in character classes now makes use
1224            of the new class addition function, using character lists defined as
1225            macros alongside the case definitions of 20 above.
1227        (e) Caseless back references now work with characters that have more than
1228            one other case.
1230        (f) General caseless matching of characters with more than one other case
1231            is supported.
1233    22. Unicode character properties were updated from Unicode 6.2.0
1235    23. Improved CMake support under Windows. Patch by Daniel Richard G.
1237    24. Add support for 32-bit character strings, and UTF-32
1239    25. Major JIT compiler update (code refactoring and bugfixing).
1240        Experimental Sparc 32 support is added.
1242    26. Applied a modified version of Daniel Richard G's patch to create
1243        pcre.h.generic and config.h.generic by "make" instead of in the
1244        PrepareRelease script.
1246    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1247        pcre_compile.c when checking for a zero character.
1249    28. Introducing a native interface for JIT. Through this interface, the compiled
1250        machine code can be directly executed. The purpose of this interface is to
1251        provide fast pattern matching, so several sanity checks are not performed.
1252        However, feature tests are still performed. The new interface provides
1253        1.4x speedup compared to the old one.
1255    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1256        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1257        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1259    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1260        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1261        the "old" RFC 2279). Instead, it ended up passing a negative length to
1262        pcre_exec().
1264    31. Add support for GCC's visibility feature to hide internal functions.
1266    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1267        "unknown -C option" after outputting 0 or 1.
1269    33. There is now support for generating a code coverage report for the test
1270        suite in environments where gcc is the compiler and lcov is installed. This
1271        is mainly for the benefit of the developers.
1273    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1274        unaddressable using valgrind annotations, allowing valgrind to detect
1275        invalid memory accesses. This is mainly for the benefit of the developers.
1277    25. (*UTF) can now be used to start a pattern in any of the three libraries.
1279    26. Give configure error if --enable-cpp but no C++ compiler found.
1282    Version 8.31 06-July-2012
1283    -------------------------
1285    1.  Fixing a wrong JIT test case and some compiler warnings.
1287    2.  Removed a bashism from the RunTest script.
1289    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1290        to unsigned type, result still unsigned" that was given by an MS compiler
1291        on encountering the code "-sizeof(xxx)".
1293    4.  Partial matching support is added to the JIT compiler.
1295    5.  Fixed several bugs concerned with partial matching of items that consist
1296        of more than one character:
1298        (a) /^(..)\1/ did not partially match "aba" because checking references was
1299            done on an "all or nothing" basis. This also applied to repeated
1300            references.
1302        (b) \R did not give a hard partial match if \r was found at the end of the
1303            subject.
1305        (c) \X did not give a hard partial match after matching one or more
1306            characters at the end of the subject.
1308        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1309            a partial match for the string "\r".
1311        (e) When newline was set to CRLF, the metacharacter "." did not recognize
1312            a partial match for a CR character at the end of the subject string.
1314    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1315        running pcretest, the text "(JIT)" added to the output whenever JIT is
1316        actually used to run the match.
1318    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
1319        or /S+[+] with a digit between 1 and 7.
1321    8.  OP_NOT now supports any UTF character not just single-byte ones.
1323    9.  (*MARK) control verb is now supported by the JIT compiler.
1325    10. The command "./RunTest list" lists the available tests without actually
1326        running any of them. (Because I keep forgetting what they all are.)
1330    12. Applied a (slightly modified) user-supplied patch that improves performance
1331        when the heap is used for recursion (compiled with --disable-stack-for-
1332        recursion). Instead of malloc and free for each heap frame each time a
1333        logical recursion happens, frames are retained on a chain and re-used where
1334        possible. This sometimes gives as much as 30% improvement.
1336    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1337        call.
1339    14. As documented, (*COMMIT) is now confined to within a positive assertion.
1341    15. It is now possible to link pcretest with libedit as an alternative to
1342        libreadline.
1344    16. (*COMMIT) control verb is now supported by the JIT compiler.
1346    17. The Unicode data tables have been updated to Unicode 6.1.0.
1348    18. Added --file-list option to pcregrep.
1350    19. Added binary file support to pcregrep, including the -a, --binary-files,
1351        -I, and --text options.
1353    20. The madvise function is renamed for posix_madvise for QNX compatibility
1354        reasons. Fixed by Giuseppe D'Angelo.
1356    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1358    22. Changed the option for creating symbolic links for 16-bit man pages from
1359        -s to -sf so that re-installing does not cause issues.
1361    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1363    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1364        matches in certain environments (the workspace was not being correctly
1365        retained). Also added to pcre_dfa_exec() a simple plausibility check on
1366        some of the workspace data at the beginning of a restart.
1368    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1369        was not doing so when it should - probably a typo introduced by SVN 528
1370        (change 8.10/14).
1372    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1373        \w+ when the character tables indicated that \x{c4} was a word character.
1374        There were several related cases, all because the tests for doing a table
1375        lookup were testing for characters less than 127 instead of 255.
1377    27. If a pattern contains capturing parentheses that are not used in a match,
1378        their slots in the ovector are set to -1. For those that are higher than
1379        any matched groups, this happens at the end of processing. In the case when
1380        there were back references that the ovector was too small to contain
1381        (causing temporary malloc'd memory to be used during matching), and the
1382        highest capturing number was not used, memory off the end of the ovector
1383        was incorrectly being set to -1. (It was using the size of the temporary
1384        memory instead of the true size.)
1386    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1387        ovector size, it uses memory at the end of the block that it has got.
1389    29. Check for an overlong MARK name and give an error at compile time. The
1390        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1392    30. JIT compiler update.
1394    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1395        Rill for the patch.
1397    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1399    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1401    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1402        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1403        was enabled.
1405    35. Improve JIT code generation for greedy plus quantifier.
1407    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1408        1 to "aa" instead of to an empty string. The bug affected repeated groups
1409        that could potentially match an empty string.
1411    37. Optimizing single character iterators in JIT.
1413    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1414        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1415        codepoints that are too big for the mode are faulted, and in a UTF mode,
1416        disallowed codepoints are also faulted.
1418    39. If PCRE was compiled with UTF support, in three places in the DFA
1419        matcher there was code that should only have been obeyed in UTF mode, but
1420        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1421        processing when bytes with values greater than 127 were present. In 16-bit
1422        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1423        both cases the values are those that cannot be the first data item in a UTF
1424        character. The three items that might have provoked this were recursions,
1425        possessively repeated groups, and atomic groups.
1427    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1428        and pcregrep, because some OS require shared objects to be explicitly
1429        passed to ld, causing the link step to fail if they are not.
1431    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1432        mode, patterns that started with \h* or \R* might be incorrectly matched.
1435    Version 8.30 04-February-2012
1436    -----------------------------
1438    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
1439        name is defined in ctype.h.
1441    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
1442        only in quite long subpatterns.
1444    3.  Removed the function pcre_info(), which has been obsolete and deprecated
1445        since it was replaced by pcre_fullinfo() in February 2000.
1447    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
1448        match a (*MARK), and the match failed at the start of the subject, a
1449        reference to memory before the start of the subject could occur. This bug
1450        was introduced by fix 17 of release 8.21.
1452    5.  A reference to an unset group with zero minimum repetition was giving
1453        totally wrong answers (in non-JavaScript-compatibility mode). For example,
1454        /(another)?(\1?)test/ matched against "hello world test". This bug was
1455        introduced in release 8.13.
1457    6.  Add support for 16-bit character strings (a large amount of work involving
1458        many changes and refactorings).
1460    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1461        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1462        from a file.
1464    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1465        rounding is not applied in this particular case).
1467    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1468        if they appear, or are escaped, in patterns.
1470    10. Get rid of a number of -Wunused-but-set-variable warnings.
1472    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1473        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1474        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1475        also returns the mark "x". This bug applied to capturing parentheses,
1476        non-capturing parentheses, and atomic parentheses. It also applied to some
1477        assertions.
1479    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1480        information out of configure.ac instead of relying on pcre.h.generic, which
1481        is not stored in the repository.
1483    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1484        -lreadline.
1486    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1488    15. Applied Graycode's patch to put the top-level frame on the stack rather
1489        than the heap when not using the stack for recursion. This gives a
1490        performance improvement in many cases when recursion is not deep.
1492    16. Experimental code added to "pcretest -C" to output the stack frame size.
1495    Version 8.21 12-Dec-2011
1496    ------------------------
1498    1.  Updating the JIT compiler.
1500    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1501        are added as well.
1503    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1504        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1505        calling _pcre_jit_exec. Some extra comments are added.
1507    4.  (*MARK) settings inside atomic groups that do not contain any capturing
1508        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1509        was introduced by change 18 for 8.20.
1511    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1512        ECMA-262 standard.
1514    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1515        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1516        This bug was probably introduced by change 9 of 8.13.
1518    7.  While fixing 6 above, I noticed that a number of other items were being
1519        incorrectly rejected as "not fixed length". This arose partly because newer
1520        opcodes had not been added to the fixed-length checking code. I have (a)
1521        corrected the bug and added tests for these items, and (b) arranged for an
1522        error to occur if an unknown opcode is encountered while checking for fixed
1523        length instead of just assuming "not fixed length". The items that were
1524        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1525        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1526        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1528    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1529        being incorrectly compiled and would have given unpredicatble results.
1531    9.  A possessively repeated subpattern with minimum repeat count greater than
1532        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1533        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1534        the first (A) could occur when it should not.
1536    10. Add a cast and remove a redundant test from the code.
1538    11. JIT should use pcre_malloc/pcre_free for allocation.
1540    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1541        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1542        is anything other than /usr, -L is still shown).
1544    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1546    14. Perl does not support \N without a following name in a [] class; PCRE now
1547        also gives an error.
1549    15. If a forward reference was repeated with an upper limit of around 2000,
1550        it caused the error "internal error: overran compiling workspace". The
1551        maximum number of forward references (including repeats) was limited by the
1552        internal workspace, and dependent on the LINK_SIZE. The code has been
1553        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1554        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1555        of around 200,000 forward references. While doing this, I also speeded up
1556        the filling in of repeated forward references.
1558    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1559        incorrectly expecting the subject to contain another "a" after the start.
1561    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1562        in the match, the SKIP should be ignored. This was not happening; instead
1563        the SKIP was being treated as NOMATCH. For patterns such as
1564        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1565        tested.
1567    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1568        now much more compatible with Perl, in particular in cases where the result
1569        is a non-match for a non-anchored pattern. For example, if
1570        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1571        "m", where previously it did not return a name. A side effect of this
1572        change is that for partial matches, the last encountered mark name is
1573        returned, as for non matches. A number of tests that were previously not
1574        Perl-compatible have been moved into the Perl-compatible test files. The
1575        refactoring has had the pleasing side effect of removing one argument from
1576        the match() function, thus reducing its stack requirements.
1578    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1579        subsequent uses of /S (without +) incorrectly behaved like /S+.
1581    21. Retrieve executable code size support for the JIT compiler and fixing
1582        some warnings.
1584    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1585        not work when the shorter character appeared right at the end of the
1586        subject string.
1588    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1589        systems.
1591    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1592        output it when the /M option is used in pcretest.
1594    25. The CheckMan script was not being included in the distribution. Also, added
1595        an explicit "perl" to run Perl scripts from the PrepareRelease script
1596        because this is reportedly needed in Windows.
1598    26. If study data was being save in a file and studying had not found a set of
1599        "starts with" bytes for the pattern, the data written to the file (though
1600        never used) was taken from uninitialized memory and so caused valgrind to
1601        complain.
1603    27. Updated RunTest.bat as provided by Sheri Pierce.
1605    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1607    29. Computation of memory usage for the table of capturing group names was
1608        giving an unnecessarily large value.
1611    Version 8.20 21-Oct-2011
1612    ------------------------
1614    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1615        a POSIX class. After further experiments with Perl, which convinced me that
1616        Perl has bugs and confusions, a closing square bracket is no longer allowed
1617        in a POSIX name. This bug also affected patterns with classes that started
1618        with full stops.
1620    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1621        captured substring, but while checking the failing first alternative,
1622        substring 1 is temporarily captured. If the output vector supplied to
1623        pcre_exec() was not big enough for this capture, the yield of the function
1624        was still zero ("insufficient space for captured substrings"). This cannot
1625        be totally fixed without adding another stack variable, which seems a lot
1626        of expense for a edge case. However, I have improved the situation in cases
1627        such as /(a)(b)x|abc/ matched against "abc", where the return code
1628        indicates that fewer than the maximum number of slots in the ovector have
1629        been set.
1631    3.  Related to (2) above: when there are more back references in a pattern than
1632        slots in the output vector, pcre_exec() uses temporary memory during
1633        matching, and copies in the captures as far as possible afterwards. It was
1634        using the entire output vector, but this conflicts with the specification
1635        that only 2/3 is used for passing back captured substrings. Now it uses
1636        only the first 2/3, for compatibility. This is, of course, another edge
1637        case.
1639    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1640        main code base, and can be used by building with --enable-jit. When this is
1641        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1642        runtime --no-jit option is given.
1644    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1645        ovector, the return from the function was zero, implying that there were
1646        other matches that did not fit. The correct "exactly full" value is now
1647        returned.
1649    6.  If a subpattern that was called recursively or as a subroutine contained
1650        (*PRUNE) or any other control that caused it to give a non-standard return,
1651        invalid errors such as "Error -26 (nested recursion at the same subject
1652        position)" or even infinite loops could occur.
1654    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1655        computing the minimum length on reaching *ACCEPT, and so ended up with the
1656        wrong value of 1 rather than 0. Further investigation indicates that
1657        computing a minimum subject length in the presence of *ACCEPT is difficult
1658        (think back references, subroutine calls), and so I have changed the code
1659        so that no minimum is registered for a pattern that contains *ACCEPT.
1661    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1662        it was not handled as intended. [But see 16 below.]
1664    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1665        Sheri Pierce.
1667    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1668        the first byte in a match must be "a".
1670    11. Change 17 for 8.13 increased the recursion depth for patterns like
1671        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1672        pattern contains any instances of (*THEN). If it does not, the old
1673        optimizations are restored. It would be nice to do this on a per-group
1674        basis, but at the moment that is not feasible.
1676    12. In some environments, the output of pcretest -C is CRLF terminated. This
1677        broke RunTest's code that checks for the link size. A single white space
1678        character after the value is now allowed for.
1680    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1681        For "fr", it uses the Windows-specific input and output files.
1683    14. If (*THEN) appeared in a group that was called recursively or as a
1684        subroutine, it did not work as intended. [But see next item.]
1686    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1687        pattern fragments (but not containing any | characters). If A and B are
1688        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1689        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1690        D. In other words, Perl considers parentheses that do not contain any |
1691        characters to be part of a surrounding alternative, whereas PCRE was
1692        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1693        differently. PCRE now behaves in the same way as Perl, except in the case
1694        of subroutine/recursion calls such as (?1) which have in any case always
1695        been different (but PCRE had them first :-).
1697    16. Related to 15 above: Perl does not treat the | in a conditional group as
1698        creating alternatives. Such a group is treated in the same way as an
1699        ordinary group without any | characters when processing (*THEN). PCRE has
1700        been changed to match Perl's behaviour.
1702    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1703        RunGrepTest script failed.
1705    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1706        inevitable for groups that contain captures, but it can lead to a lot of
1707        stack use in large patterns. The old behaviour has been restored for atomic
1708        groups that do not contain any capturing parentheses.
1710    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1711        suppress the check for a minimum subject length at run time. (If it was
1712        given to pcre_exec() or pcre_dfa_exec() it did work.)
1714    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1715        fail to work when decoding hex characters in data strings in EBCDIC
1716        environments.
1718    21. It appears that in at least one Mac OS environment, the isxdigit() function
1719        is implemented as a macro that evaluates to its argument more than once,
1720        contravening the C 90 Standard (I haven't checked a later standard). There
1721        was an instance in pcretest which caused it to go wrong when processing
1722        \x{...} escapes in subject strings. The has been rewritten to avoid using
1723        things like p++ in the argument of isxdigit().
1726    Version 8.13 16-Aug-2011
1727  ------------------------  ------------------------
1729  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 98  Version 8.13 02-Aug-2011 Line 1820  Version 8.13 02-Aug-2011
1820      tail recursion to cut down on stack usage. Unfortunately, now that there is      tail recursion to cut down on stack usage. Unfortunately, now that there is
1821      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
1822      no longer possible because the return has to be checked for (*THEN). These      no longer possible because the return has to be checked for (*THEN). These
1823      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
1825  18. If a pattern containing \R was studied, it was assumed that \R always  18. If a pattern containing \R was studied, it was assumed that \R always
1826      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
# Line 189  Version 8.13 02-Aug-2011 Line 1911  Version 8.13 02-Aug-2011
1911      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1912      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
1913      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1914      more like Perl.      more like Perl. (But see 8.20/1 above.)
1916  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1917      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).
# Line 224  Version 8.13 02-Aug-2011 Line 1946  Version 8.13 02-Aug-2011
1946      (a) The default value of the buffer size parameter has been increased from      (a) The default value of the buffer size parameter has been increased from
1947          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
1949      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1950          PCRE is built.          PCRE is built.
1952      (c) A --buffer-size=n option has been added to pcregrep, to allow the size      (c) A --buffer-size=n option has been added to pcregrep, to allow the size
# Line 245  Version 8.13 02-Aug-2011 Line 1967  Version 8.13 02-Aug-2011
1967  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1968      complete match instead of a partial match. This bug was dependent on both      complete match instead of a partial match. This bug was dependent on both
1969      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
1971  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1972      starting byte set, because \b was not being ignored.      starting byte set, because \b was not being ignored.
1975  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
# Line 900  Version 7.9 11-Apr-09 Line 2622  Version 7.9 11-Apr-09
2622  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
2623      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
2624      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2625      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2626        8.33.]
2628  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
2629      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 1143  Version 7.7 07-May-08 Line 2866  Version 7.7 07-May-08
2866      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2867      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2868      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2869      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2870      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2871      was subsequently set up correctly.)      was subsequently set up correctly.)

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