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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 8.38 xx-xxx-xxxx
8    ------------------------
10    1.  If a group that contained a recursive back reference also contained a
11        forward reference subroutine call followed by a non-forward-reference
12        subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13        compile correct code, leading to undefined behaviour or an internally
14        detected error. This bug was discovered by the LLVM fuzzer.
16    2.  Quantification of certain items (e.g. atomic back references) could cause
17        incorrect code to be compiled when recursive forward references were
18        involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19        This bug was discovered by the LLVM fuzzer.
21    3.  A repeated conditional group whose condition was a reference by name caused
22        a buffer overflow if there was more than one group with the given name.
23        This bug was discovered by the LLVM fuzzer.
25    4.  A recursive back reference by name within a group that had the same name as
26        another group caused a buffer overflow. For example:
27        /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
29    5.  A forward reference by name to a group whose number is the same as the
30        current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31        a buffer overflow at compile time. This bug was discovered by the LLVM
32        fuzzer.
34    6.  A lookbehind assertion within a set of mutually recursive subpatterns could
35        provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
37    7.  Another buffer overflow bug involved duplicate named groups with a
38        reference between their definition, with a group that reset capture
39        numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40        fixed by always allowing for more memory, even if not needed. (A proper fix
41        is implemented in PCRE2, but it involves more refactoring.)
43    8.  There was no check for integer overflow in subroutine calls such as (?123).
45    9.  The table entry for \l in EBCDIC environments was incorrect, leading to its
46        being treated as a literal 'l' instead of causing an error.
48    10. There was a buffer overflow if pcre_exec() was called with an ovector of
49        size 1. This bug was found by american fuzzy lop.
51    11. If a non-capturing group containing a conditional group that could match
52        an empty string was repeated, it was not identified as matching an empty
53        string itself. For example: /^(?:(?(1)x|)+)+$()/.
55    12. In an EBCDIC environment, pcretest was mishandling the escape sequences
56        \a and \e in test subject lines.
58    13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
59        instead of the EBCDIC value.
61    14. The handling of \c in an EBCDIC environment has been revised so that it is
62        now compatible with the specification in Perl's perlebcdic page.
64    15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
65        ASCII/Unicode. This has now been added to the list of characters that are
66        recognized as white space in EBCDIC.
68    16. When PCRE was compiled without UCP support, the use of \p and \P gave an
69        error (correctly) when used outside a class, but did not give an error
70        within a class.
72    17. \h within a class was incorrectly compiled in EBCDIC environments.
74    18. A pattern with an unmatched closing parenthesis that contained a backward
75        assertion which itself contained a forward reference caused buffer
76        overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
78    19. JIT should return with error when the compiled pattern requires more stack
79        space than the maximum.
81    20. A possessively repeated conditional group that could match an empty string,
82        for example, /(?(R))*+/, was incorrectly compiled.
84    21. Fix infinite recursion in the JIT compiler when certain patterns such as
85        /(?:|a|){100}x/ are analysed.
87    22. Some patterns with character classes involving [: and \\ were incorrectly
88        compiled and could cause reading from uninitialized memory or an incorrect
89        error diagnosis.
91    23. Pathological patterns containing many nested occurrences of [: caused
92        pcre_compile() to run for a very long time.
94    24. A conditional group with only one branch has an implicit empty alternative
95        branch and must therefore be treated as potentially matching an empty
96        string.
98    25. If (?R was followed by - or + incorrect behaviour happened instead of a
99        diagnostic.
101    26. Arrange to give up on finding the minimum matching length for overly
102        complex patterns.
104    27. Similar to (4) above: in a pattern with duplicated named groups and an
105        occurrence of (?| it is possible for an apparently non-recursive back
106        reference to become recursive if a later named group with the relevant
107        number is encountered. This could lead to a buffer overflow. Wen Guanxing
108        from Venustech ADLAB discovered this bug.
110    28. If pcregrep was given the -q option with -c or -l, or when handling a
111        binary file, it incorrectly wrote output to stdout.
113    29. The JIT compiler did not restore the control verb head in case of *THEN
114        control verbs. This issue was found by Karl Skomski with a custom LLVM
115        fuzzer.
117    30. Error messages for syntax errors following \g and \k were giving inaccurate
118        offsets in the pattern.
120    31. Added a check for integer overflow in conditions (?(<digits>) and
121        (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
122        fuzzer.
124    32. Handling recursive references such as (?2) when the reference is to a group
125        later in the pattern uses code that is very hacked about and error-prone.
126        It has been re-written for PCRE2. Here in PCRE1, a check has been added to
127        give an internal error if it is obvious that compiling has gone wrong.
129    33. The JIT compiler should not check repeats after a {0,1} repeat byte code.
130        This issue was found by Karl Skomski with a custom LLVM fuzzer.
132    34. The JIT compiler should restore the control chain for empty possessive
133        repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer.
135    35. Match limit check added to recursion. This issue was found by Karl Skomski
136        with a custom LLVM fuzzer.
139    Version 8.37 28-April-2015
140    --------------------------
142    1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
143        for those parentheses to be closed with whatever has been captured so far.
144        However, it was failing to mark any other groups between the hightest
145        capture so far and the currrent group as "unset". Thus, the ovector for
146        those groups contained whatever was previously there. An example is the
147        pattern /(x)|((*ACCEPT))/ when matched against "abcd".
149    2.  If an assertion condition was quantified with a minimum of zero (an odd
150        thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
152    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
153        unrecognized modifier, a crash could occur.
155    4.  An attempt to do global matching in pcretest with a zero-length ovector
156        caused a crash.
158    5.  Fixed a memory leak during matching that could occur for a subpattern
159        subroutine call (recursive or otherwise) if the number of captured groups
160        that had to be saved was greater than ten.
162    6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
163        string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
164        UTF with NO_UTF_CHECK is documented as having an undefined outcome.
166    7.  A UTF pattern containing a "not" match of a non-ASCII character and a
167        subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
169    8. When a pattern is compiled, it remembers the highest back reference so that
170       when matching, if the ovector is too small, extra memory can be obtained to
171       use instead. A conditional subpattern whose condition is a check on a
172       capture having happened, such as, for example in the pattern
173       /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
174       setting the highest backreference number. This mattered only if pcre_exec()
175       was called with an ovector that was too small to hold the capture, and there
176       was no other kind of back reference (a situation which is probably quite
177       rare). The effect of the bug was that the condition was always treated as
178       FALSE when the capture could not be consulted, leading to a incorrect
179       behaviour by pcre_exec(). This bug has been fixed.
181    9. A reference to a duplicated named group (either a back reference or a test
182       for being set in a conditional) that occurred in a part of the pattern where
183       PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
184       to be incorrectly calculated, leading to overwriting.
186    10. A mutually recursive set of back references such as (\2)(\1) caused a
187        segfault at study time (while trying to find the minimum matching length).
188        The infinite loop is now broken (with the minimum length unset, that is,
189        zero).
191    11. If an assertion that was used as a condition was quantified with a minimum
192        of zero, matching went wrong. In particular, if the whole group had
193        unlimited repetition and could match an empty string, a segfault was
194        likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
195        assertions to be quantified, but not if they are being used as conditions,
196        so the above pattern is faulted by Perl. PCRE has now been changed so that
197        it also rejects such patterns.
199    12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
200        failed to allow the zero-repeat case if pcre2_exec() was called with an
201        ovector too small to capture the group.
203    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
204        Red Hat Product Security:
206        (a) A crash if /K and /F were both set with the option to save the compiled
207        pattern.
209        (b) Another crash if the option to print captured substrings in a callout
210        was combined with setting a null ovector, for example \O\C+ as a subject
211        string.
213    14. A pattern such as "((?2){0,1999}())?", which has a group containing a
214        forward reference repeated a large (but limited) number of times within a
215        repeated outer group that has a zero minimum quantifier, caused incorrect
216        code to be compiled, leading to the error "internal error:
217        previously-checked referenced subpattern not found" when an incorrect
218        memory address was read. This bug was reported as "heap overflow",
219        discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
220        CVE-2015-2325.
222    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
223        call within a group that also contained a recursive back reference caused
224        incorrect code to be compiled. This bug was reported as "heap overflow",
225        discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
226        number CVE-2015-2326.
228    24. Computing the size of the JIT read-only data in advance has been a source
229        of various issues, and new ones are still appear unfortunately. To fix
230        existing and future issues, size computation is eliminated from the code,
231        and replaced by on-demand memory allocation.
233    25. A pattern such as /(?i)[A-`]/, where characters in the other case are
234        adjacent to the end of the range, and the range contained characters with
235        more than one other case, caused incorrect behaviour when compiled in UTF
236        mode. In that example, the range a-j was left out of the class.
238    26. Fix JIT compilation of conditional blocks, which assertion
239        is converted to (*FAIL). E.g: /(?(?!))/.
241    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
242        discovered by the LLVM fuzzer.
244    28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
245        when this assertion was used as a condition, for example (?(?!)a|b). In
246        pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
247        error about an unsupported item.
249    29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
250        possessification code could take exponential time to complete. A recursion
251        depth limit of 1000 has been imposed to limit the resources used by this
252        optimization.
254    30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
255        such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
256        because \S ensures they are all in the class. The code for doing this was
257        interacting badly with the code for computing the amount of space needed to
258        compile the pattern, leading to a buffer overflow. This bug was discovered
259        by the LLVM fuzzer.
261    31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
262        other kinds of group caused stack overflow at compile time. This bug was
263        discovered by the LLVM fuzzer.
265    32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
266        between a subroutine call and its quantifier was incorrectly compiled,
267        leading to buffer overflow or other errors. This bug was discovered by the
268        LLVM fuzzer.
270    33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
271        assertion after (?(. The code was failing to check the character after
272        (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
273        was discovered by the LLVM fuzzer.
275    34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
276        a fixed maximum following a group that contains a subroutine reference was
277        incorrectly compiled and could trigger buffer overflow. This bug was
278        discovered by the LLVM fuzzer.
280    35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
281        caused a stack overflow instead of the diagnosis of a non-fixed length
282        lookbehind assertion. This bug was discovered by the LLVM fuzzer.
284    36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
285        (e.g. /(?<=\Ka)/) could make pcregrep loop.
287    37. There was a similar problem to 36 in pcretest for global matches.
289    38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
290        and a subsequent item in the pattern caused a non-match, backtracking over
291        the repeated \X did not stop, but carried on past the start of the subject,
292        causing reference to random memory and/or a segfault. There were also some
293        other cases where backtracking after \C could crash. This set of bugs was
294        discovered by the LLVM fuzzer.
296    39. The function for finding the minimum length of a matching string could take
297        a very long time if mutual recursion was present many times in a pattern,
298        for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
299        method has been implemented. This infelicity was discovered by the LLVM
300        fuzzer.
302    40. Static linking against the PCRE library using the pkg-config module was
303        failing on missing pthread symbols.
306    Version 8.36 26-September-2014
307    ------------------------------
309    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
310        -Wmissing-field-initializers and -Wunused-parameter.
312    2.  The tests for quantifiers being too big (greater than 65535) were being
313        applied after reading the number, and stupidly assuming that integer
314        overflow would give a negative number. The tests are now applied as the
315        numbers are read.
317    3.  Tidy code in pcre_exec.c where two branches that used to be different are
318        now the same.
320    4.  The JIT compiler did not generate match limit checks for certain
321        bracketed expressions with quantifiers. This may lead to exponential
322        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
323        issue should be resolved now.
325    5.  Fixed an issue, which occures when nested alternatives are optimized
326        with table jumps.
328    6.  Inserted two casts and changed some ints to size_t in the light of some
329        reported 64-bit compiler warnings (Bugzilla 1477).
331    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
332        an empty string, which sometimes were behaving incorrectly in the
333        interpreter (though correctly in the JIT matcher). This pcretest input is
334        an example:
336          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
339        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
340        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
341        for an empty string was breaking the inner loop and carrying on at a lower
342        level, when possessive repeated groups should always return to a higher
343        level as they have no backtrack points in them. The empty string test now
344        occurs at the outer level.
346    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
347        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
349    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
350        doesn't).
352    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
353        to hold a pattern to be incorrectly computed (too small) when there were
354        named back references to duplicated names. This could cause "internal
355        error: code overflow" or "double free or corruption" or other memory
356        handling errors.
358    11. When named subpatterns had the same prefixes, back references could be
359        confused. For example, in this pattern:
361          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
363        the reference to 'Name' was incorrectly treated as a reference to a
364        duplicate name.
366    12. A pattern such as /^s?c/mi8 where the optional character has more than
367        one "other case" was incorrectly compiled such that it would only try to
368        match starting at "c".
370    13. When a pattern starting with \s was studied, VT was not included in the
371        list of possible starting characters; this should have been part of the
372        8.34/18 patch.
374    14. If a character class started [\Qx]... where x is any character, the class
375        was incorrectly terminated at the ].
377    15. If a pattern that started with a caseless match for a character with more
378        than one "other case" was studied, PCRE did not set up the starting code
379        unit bit map for the list of possible characters. Now it does. This is an
380        optimization improvement, not a bug fix.
382    16. The Unicode data tables have been updated to Unicode 7.0.0.
384    17. Fixed a number of memory leaks in pcregrep.
386    18. Avoid a compiler warning (from some compilers) for a function call with
387        a cast that removes "const" from an lvalue by using an intermediate
388        variable (to which the compiler does not object).
390    19. Incorrect code was compiled if a group that contained an internal recursive
391        back reference was optional (had quantifier with a minimum of zero). This
392        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
393        caused segmentation faults because of stack overflows at compile time.
395    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
396        group that is quantified with an indefinite repeat, caused a compile-time
397        loop which used up all the system stack and provoked a segmentation fault.
398        This was not the same bug as 19 above.
400    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
401        Patch by Mike Frysinger.
404    Version 8.35 04-April-2014
405    --------------------------
407    1.  A new flag is set, when property checks are present in an XCLASS.
408        When this flag is not set, PCRE can perform certain optimizations
409        such as studying these XCLASS-es.
411    2.  The auto-possessification of character sets were improved: a normal
412        and an extended character set can be compared now. Furthermore
413        the JIT compiler optimizes more character set checks.
415    3.  Got rid of some compiler warnings for potentially uninitialized variables
416        that show up only when compiled with -O2.
418    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
419        of a match later then the end of the match. The pcretest program was not
420        handling the case sensibly - it was outputting from the start to the next
421        binary zero. It now reports this situation in a message, and outputs the
422        text from the end to the start.
424    5.  Fast forward search is improved in JIT. Instead of the first three
425        characters, any three characters with fixed position can be searched.
426        Search order: first, last, middle.
428    6.  Improve character range checks in JIT. Characters are read by an inprecise
429        function now, which returns with an unknown value if the character code is
430        above a certain threshold (e.g: 256). The only limitation is that the value
431        must be bigger than the threshold as well. This function is useful when
432        the characters above the threshold are handled in the same way.
434    7.  The macros whose names start with RAWUCHAR are placeholders for a future
435        mode in which only the bottom 21 bits of 32-bit data items are used. To
436        make this more memorable for those maintaining the code, the names have
437        been changed to start with UCHAR21, and an extensive comment has been added
438        to their definition.
440    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
441        to the export list in Makefile.am (they were accidentally omitted from the
442        8.34 tarball).
444    9.  The informational output from pcretest used the phrase "starting byte set"
445        which is inappropriate for the 16-bit and 32-bit libraries. As the output
446        for "first char" and "need char" really means "non-UTF-char", I've changed
447        "byte" to "char", and slightly reworded the output. The documentation about
448        these values has also been (I hope) clarified.
450    10. Another JIT related optimization: use table jumps for selecting the correct
451        backtracking path, when more than four alternatives are present inside a
452        bracket.
454    11. Empty match is not possible, when the minimum length is greater than zero,
455        and there is no \K in the pattern. JIT should avoid empty match checks in
456        such cases.
458    12. In a caseless character class with UCP support, when a character with more
459        than one alternative case was not the first character of a range, not all
460        the alternative cases were added to the class. For example, s and \x{17f}
461        are both alternative cases for S: the class [RST] was handled correctly,
462        but [R-T] was not.
464    13. The configure.ac file always checked for pthread support when JIT was
465        enabled. This is not used in Windows, so I have put this test inside a
466        check for the presence of windows.h (which was already tested for).
468    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
469        The algorithm provides a way to skip certain starting offsets, and usually
470        faster than linear prefix searches.
472    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
473        as for 'fr_FR' and 'french'. For some reason, however, it then used the
474        Windows-specific input and output files, which have 'french' screwed in.
475        So this could never have worked. One of the problems with locales is that
476        they aren't always the same. I have now updated RunTest so that it checks
477        the output of the locale test (test 3) against three different output
478        files, and it allows the test to pass if any one of them matches. With luck
479        this should make the test pass on some versions of Solaris where it was
480        failing. Because of the uncertainty, the script did not used to stop if
481        test 3 failed; it now does. If further versions of a French locale ever
482        come to light, they can now easily be added.
484    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
485        there was a message during ./configure, but it did not stop. This now
486        provokes an error. The invalid example in README has been corrected.
487        If a value less than the minimum is given, the minimum value has always
488        been used, but now a warning is given.
490    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
491        was a bug in the test system, which is now fixed. Also, the list of various
492        configurations that are tested for each release did not have one with both
493        16/32 bits and --enable-bar-anycrlf. It now does.
495    18. pcretest was missing "-C bsr" for displaying the \R default setting.
497    19. Little endian PowerPC systems are supported now by the JIT compiler.
499    20. The fast forward newline mechanism could enter to an infinite loop on
500        certain invalid UTF-8 input. Although we don't support these cases
501        this issue can be fixed by a performance optimization.
503    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
504        not take account if existing stack usage. There is now a new global
505        variable called pcre_stack_guard that can be set to point to an external
506        function to check stack availability. It is called at the start of
507        processing every parenthesized group.
509    22. A typo in the code meant that in ungreedy mode the max/min qualifier
510        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
511        not match "ab".
513    23. When UTF was disabled, the JIT program reported some incorrect compile
514        errors. These messages are silenced now.
516    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
517        compiler.
519    25. Change all the temporary files used in RunGrepTest to be different to those
520        used by RunTest so that the tests can be run simultaneously, for example by
521        "make -j check".
524    Version 8.34 15-December-2013
525    -----------------------------
527    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
528        executable memory. Patch inspired by Carsten Klein.
530    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
531        this macro is never tested and has no effect, because the work to support
532        coverage involves only compiling and linking options and special targets in
533        the Makefile. The comment in config.h implied that defining the macro would
534        enable coverage support, which is totally false. There was also support for
535        setting this macro in the CMake files (my fault, I just copied it from
536        configure). SUPPORT_GCOV has now been removed.
538    3.  Make a small performance improvement in strlen16() and strlen32() in
539        pcretest.
541    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
542        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
543        these cases). There was also one in pcretest.c.
545    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
547    6.  In UTF mode, the code for checking whether a group could match an empty
548        string (which is used for indefinitely repeated groups to allow for
549        breaking an infinite loop) was broken when the group contained a repeated
550        negated single-character class with a character that occupied more than one
551        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
552        UTF-8 mode). The effect was undefined: the group might or might not be
553        deemed as matching an empty string, or the program might have crashed.
555    7.  The code for checking whether a group could match an empty string was not
556        recognizing that \h, \H, \v, \V, and \R must match a character.
558    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
559        an empty string. If it can, pcretest shows this in its information output.
561    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
562        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
563        matched by pcre_exec() without using JIT:
565        (a) If the rest of the pattern did not match after a maximal run of
566            grapheme clusters, the code for backing up to try with fewer of them
567            did not always back up over a full grapheme when characters that do not
568            have the modifier quality were involved, e.g. Hangul syllables.
570        (b) If the match point in a subject started with modifier character, and
571            there was no match, the code could incorrectly back up beyond the match
572            point, and potentially beyond the first character in the subject,
573            leading to a segfault or an incorrect match result.
575    10. A conditional group with an assertion condition could lead to PCRE
576        recording an incorrect first data item for a match if no other first data
577        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
578        first data item, and therefore matched "ca" after "c" instead of at the
579        start.
581    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
582        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
584    12. The source of pcregrep now includes z/OS-specific code so that it can be
585        compiled for z/OS as part of the special z/OS distribution.
587    13. Added the -T and -TM options to pcretest.
589    14. The code in pcre_compile.c for creating the table of named capturing groups
590        has been refactored. Instead of creating the table dynamically during the
591        actual compiling pass, the information is remembered during the pre-compile
592        pass (on the stack unless there are more than 20 named groups, in which
593        case malloc() is used) and the whole table is created before the actual
594        compile happens. This has simplified the code (it is now nearly 150 lines
595        shorter) and prepared the way for better handling of references to groups
596        with duplicate names.
598    15. A back reference to a named subpattern when there is more than one of the
599        same name now checks them in the order in which they appear in the pattern.
600        The first one that is set is used for the reference. Previously only the
601        first one was inspected. This change makes PCRE more compatible with Perl.
603    16. Unicode character properties were updated from Unicode 6.3.0.
605    17. The compile-time code for auto-possessification has been refactored, based
606        on a patch by Zoltan Herczeg. It now happens after instead of during
607        compilation. The code is cleaner, and more cases are handled. The option
608        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
609        options in pcretest are provided to set it. It can also be set by
610        (*NO_AUTO_POSSESS) at the start of a pattern.
612    18. The character VT has been added to the default ("C" locale) set of
613        characters that match \s and are generally treated as white space,
614        following this same change in Perl 5.18. There is now no difference between
615        "Perl space" and "POSIX space". Whether VT is treated as white space in
616        other locales depends on the locale.
618    19. The code for checking named groups as conditions, either for being set or
619        for being recursed, has been refactored (this is related to 14 and 15
620        above). Processing unduplicated named groups should now be as fast at
621        numerical groups, and processing duplicated groups should be faster than
622        before.
624    20. Two patches to the CMake build system, by Alexander Barkov:
626          (1) Replace the "source" command by "." in CMakeLists.txt because
627              "source" is a bash-ism.
629          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
630              without these the CMake build does not work on Solaris.
632    21. Perl has changed its handling of \8 and \9. If there is no previously
633        encountered capturing group of those numbers, they are treated as the
634        literal characters 8 and 9 instead of a binary zero followed by the
635        literals. PCRE now does the same.
637    22. Following Perl, added \o{} to specify codepoints in octal, making it
638        possible to specify values greater than 0777 and also making them
639        unambiguous.
641    23. Perl now gives an error for missing closing braces after \x{... instead of
642        treating the string as literal. PCRE now does the same.
644    24. RunTest used to grumble if an inappropriate test was selected explicitly,
645        but just skip it when running all tests. This make it awkward to run ranges
646        of tests when one of them was inappropriate. Now it just skips any
647        inappropriate tests, as it always did when running all tests.
649    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
650        character types such as \d or \w, too many callouts were inserted, and the
651        data that they returned was rubbish.
653    26. In UCP mode, \s was not matching two of the characters that Perl matches,
654        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
655        were matched by \h. The code has now been refactored so that the lists of
656        the horizontal and vertical whitespace characters used for \h and \v (which
657        are defined only in one place) are now also used for \s.
659    27. Add JIT support for the 64 bit TileGX architecture.
660        Patch by Jiong Wang (Tilera Corporation).
662    28. Possessive quantifiers for classes (both explicit and automatically
663        generated) now use special opcodes instead of wrapping in ONCE brackets.
665    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
666        (because it's meaningless), this was not happening when PCRE_CASELESS was
667        set. Not wrong, but inefficient.
669    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
670        properties for \w, \d, etc) is present in a test regex. Otherwise if the
671        test contains no characters greater than 255, Perl doesn't realise it
672        should be using Unicode semantics.
674    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
675        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
676        does in Unicode mode.
678    32. Added the "forbid" facility to pcretest so that putting tests into the
679        wrong test files can sometimes be quickly detected.
681    33. There is now a limit (default 250) on the depth of nesting of parentheses.
682        This limit is imposed to control the amount of system stack used at compile
683        time. It can be changed at build time by --with-parens-nest-limit=xxx or
684        the equivalent in CMake.
686    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
687        errors. Perl warns for these when in warning mode, but PCRE has no facility
688        for giving warnings.
690    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
691        However, this was not working for (?!) because it is optimized to (*FAIL),
692        for which PCRE does not allow quantifiers. The optimization is now disabled
693        when a quantifier follows (?!). I can't see any use for this, but it makes
694        things uniform.
696    36. Perl no longer allows group names to start with digits, so I have made this
697        change also in PCRE. It simplifies the code a bit.
699    37. In extended mode, Perl ignores spaces before a + that indicates a
700        possessive quantifier. PCRE allowed a space before the quantifier, but not
701        before the possessive +. It now does.
703    38. The use of \K (reset reported match start) within a repeated possessive
704        group such as (a\Kb)*+ was not working.
706    40. Document that the same character tables must be used at compile time and
707        run time, and that the facility to pass tables to pcre_exec() and
708        pcre_dfa_exec() is for use only with saved/restored patterns.
710    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
711        features for Builds with MSVC:
713        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
714           builds). The .rc files can be used to set FileDescription and many other
715           attributes.
717        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
718           This allows higher-level build scripts which want .pdb files to avoid
719           hard-coding the exact files needed."
721    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
722        mean "start of word" and "end of word", respectively, as a transition aid.
724    43. A minimizing repeat of a class containing codepoints greater than 255 in
725        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
726        compiled to use the heap for recursion.
728    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
729        is configured.
732    Version 8.33 28-May-2013
733    ------------------------
735    1.  Added 'U' to some constants that are compared to unsigned integers, to
736        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
737        variables that are added to signed variables, to ensure the result is
738        signed and can be negated.
740    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
741        CMake config files.
743    3.  Revise the creation of config.h.generic so that all boolean macros are
744        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
745        overriding via -D on the command line possible.
747    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
748        to unsigned int is reported to make a quite noticeable speed difference in
749        a specific Windows environment. Testing on Linux did also appear to show
750        some benefit (and it is clearly not harmful). Also fixed the definition of
751        Xop which should be unsigned.
753    5.  Related to (4), changing the definition of the intermediate variable cc
754        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
755        improvements.
757    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
758        unnecessary spaces.
760    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
761        and later.
763    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
765    9.  Optimizing fast_forward_start_bits in JIT.
767    10. Adding support for callouts in JIT, and fixing some issues revealed
768        during this work. Namely:
770        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
772        (b) Minimum length was not checked before the matching is started.
774    11. The value of capture_last that is passed to callouts was incorrect in some
775        cases when there was a capture on one path that was subsequently abandoned
776        after a backtrack. Also, the capture_last value is now reset after a
777        recursion, since all captures are also reset in this case.
779    12. The interpreter no longer returns the "too many substrings" error in the
780        case when an overflowing capture is in a branch that is subsequently
781        abandoned after a backtrack.
783    13. In the pathological case when an offset vector of size 2 is used, pcretest
784        now prints out the matched string after a yield of 0 or 1.
786    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
787        Only supported by the JIT compiler at the moment.
789    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
791    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
792        offset of the starting point of the matching process, provided the offsets
793        vector is large enough.
795    17. The \A escape now records a lookbehind value of 1, though its execution
796        does not actually inspect the previous character. This is to ensure that,
797        in partial multi-segment matching, at least one character from the old
798        segment is retained when a new segment is processed. Otherwise, if there
799        are no lookbehinds in the pattern, \A might match incorrectly at the start
800        of a new segment.
802    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
804    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
805        gives some modest performance improvement in 8-bit mode.
807    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
808        be expressed in certain programming languages using Universal Character
809        Names.
811    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
812        which points out that "non characters" are not "characters that may not
813        appear in Unicode strings" but rather "characters that are reserved for
814        internal use and have only local meaning".
816    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
817        there was a conditional group that depended on an assertion, if the
818        assertion was false, the callout that immediately followed the alternation
819        in the condition was skipped when pcre_exec() was used for matching.
821    23. Allow an explicit callout to be inserted before an assertion that is the
822        condition for a conditional group, for compatibility with automatic
823        callouts, which always insert a callout at this point.
825    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
826        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
828    25. (*PRUNE) is now supported by the JIT compiler.
830    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
832    27. Fix the case where there are two or more SKIPs with arguments that may be
833        ignored.
835    28. (*SKIP) is now supported by the JIT compiler.
837    29. (*THEN) is now supported by the JIT compiler.
839    30. Update RunTest with additional test selector options.
841    31. The way PCRE handles backtracking verbs has been changed in two ways.
843        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
844        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
845        backtracking. In some cases this makes it more Perl-compatible, but Perl's
846        rather obscure rules do not always do the same thing.
848        (2) Previously, backtracking verbs were confined within assertions. This is
849        no longer the case for positive assertions, except for (*ACCEPT). Again,
850        this sometimes improves Perl compatibility, and sometimes does not.
852    32. A number of tests that were in test 2 because Perl did things differently
853        have been moved to test 1, because either Perl or PCRE has changed, and
854        these tests are now compatible.
856    32. Backtracking control verbs are now handled in the same way in JIT and
857        interpreter.
859    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
860        contained a forward subroutine reference caused a compile error.
862    34. Auto-detect and optimize limited repetitions in JIT.
864    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
865        blocking (*UTF) etc.
867    36. In the interpreter, maximizing pattern repetitions for characters and
868        character types now use tail recursion, which reduces stack usage.
870    37. The value of the max lookbehind was not correctly preserved if a compiled
871        and saved regex was reloaded on a host of different endianness.
873    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
874        of the compiled pattern block, expand the flags field from 16 to 32 bits
875        because it was almost full.
877    39. Try madvise first before posix_madvise.
879    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
880        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
881        original change locked out all matches of empty strings. This has been
882        changed so that one match of an empty string per line is recognized.
883        Subsequent searches on the same line (for colouring or for --only-matching,
884        for example) do not recognize empty strings.
886    41. Applied a user patch to fix a number of spelling mistakes in comments.
888    42. Data lines longer than 65536 caused pcretest to crash.
890    43. Clarified the data type for length and startoffset arguments for pcre_exec
891        and pcre_dfa_exec in the function-specific man pages, where they were
892        explicitly stated to be in bytes, never having been updated. I also added
893        some clarification to the pcreapi man page.
895    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
896        a segmentation fault.
899    Version 8.32 30-November-2012
900    -----------------------------
902    1.  Improved JIT compiler optimizations for first character search and single
903        character iterators.
905    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
906        Patch by Daniel Richard G.
908    3.  Single character iterator optimizations in the JIT compiler.
910    4.  Improved JIT compiler optimizations for character ranges.
912    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
913        Reported by Giuseppe D'Angelo.
915    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
916        of a line, was being set incorrectly in cases where .* appeared inside
917        atomic brackets at the start of a pattern, or where there was a subsequent
918        *PRUNE or *SKIP.
920    7.  Improved instruction cache flush for POWER/PowerPC.
921        Patch by Daniel Richard G.
923    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
924        grep:
926        (a) There is now no limit to the number of patterns to be matched.
928        (b) An error is given if a pattern is too long.
930        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
931            are now supported.
933        (d) --exclude-from and --include-from (multiple use) have been added.
935        (e) Exclusions and inclusions now apply to all files and directories, not
936            just to those obtained from scanning a directory recursively.
938        (f) Multiple uses of -f and --file-list are now supported.
940        (g) In a Windows environment, the default for -d has been changed from
941            "read" (the GNU grep default) to "skip", because otherwise the presence
942            of a directory in the file list provokes an error.
944        (h) The documentation has been revised and clarified in places.
946    9.  Improve the matching speed of capturing brackets.
948    10. Changed the meaning of \X so that it now matches a Unicode extended
949        grapheme cluster.
951    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
952        out POSIX threads when JIT support is configured.
954    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
956    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
957        structure could go wrong in environments where size_t is not the same size
958        as int.
960    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
961        set.
963    15. The EBCDIC support had decayed; later updates to the code had included
964        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
965        general tidy up of EBCDIC-related issues, and the documentation was also
966        not quite right. There is now a test that can be run on ASCII systems to
967        check some of the EBCDIC-related things (but is it not a full test).
969    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
970        in a small tidy to the code.
972    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
974    18. If the --only-matching (-o) option in pcregrep is specified multiple
975        times, each one causes appropriate output. For example, -o1 -o2 outputs the
976        substrings matched by the 1st and 2nd capturing parentheses. A separating
977        string can be specified by --om-separator (default empty).
979    19. Improving the first n character searches.
981    20. Turn case lists for horizontal and vertical white space into macros so that
982        they are defined only once.
984    21. This set of changes together give more compatible Unicode case-folding
985        behaviour for characters that have more than one other case when UCP
986        support is available.
988        (a) The Unicode property table now has offsets into a new table of sets of
989            three or more characters that are case-equivalent. The MultiStage2.py
990            script that generates these tables (the pcre_ucd.c file) now scans
991            CaseFolding.txt instead of UnicodeData.txt for character case
992            information.
994        (b) The code for adding characters or ranges of characters to a character
995            class has been abstracted into a generalized function that also handles
996            case-independence. In UTF-mode with UCP support, this uses the new data
997            to handle characters with more than one other case.
999        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
1000            whose other case is greater than 256 are now correctly matched
1001            caselessly. Previously, the high codepoint matched the low one, but not
1002            vice versa.
1004        (d) The processing of \h, \H, \v, and \ in character classes now makes use
1005            of the new class addition function, using character lists defined as
1006            macros alongside the case definitions of 20 above.
1008        (e) Caseless back references now work with characters that have more than
1009            one other case.
1011        (f) General caseless matching of characters with more than one other case
1012            is supported.
1014    22. Unicode character properties were updated from Unicode 6.2.0
1016    23. Improved CMake support under Windows. Patch by Daniel Richard G.
1018    24. Add support for 32-bit character strings, and UTF-32
1020    25. Major JIT compiler update (code refactoring and bugfixing).
1021        Experimental Sparc 32 support is added.
1023    26. Applied a modified version of Daniel Richard G's patch to create
1024        pcre.h.generic and config.h.generic by "make" instead of in the
1025        PrepareRelease script.
1027    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1028        pcre_compile.c when checking for a zero character.
1030    28. Introducing a native interface for JIT. Through this interface, the compiled
1031        machine code can be directly executed. The purpose of this interface is to
1032        provide fast pattern matching, so several sanity checks are not performed.
1033        However, feature tests are still performed. The new interface provides
1034        1.4x speedup compared to the old one.
1036    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1037        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1038        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1040    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1041        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1042        the "old" RFC 2279). Instead, it ended up passing a negative length to
1043        pcre_exec().
1045    31. Add support for GCC's visibility feature to hide internal functions.
1047    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1048        "unknown -C option" after outputting 0 or 1.
1050    33. There is now support for generating a code coverage report for the test
1051        suite in environments where gcc is the compiler and lcov is installed. This
1052        is mainly for the benefit of the developers.
1054    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1055        unaddressable using valgrind annotations, allowing valgrind to detect
1056        invalid memory accesses. This is mainly for the benefit of the developers.
1058    25. (*UTF) can now be used to start a pattern in any of the three libraries.
1060    26. Give configure error if --enable-cpp but no C++ compiler found.
1063    Version 8.31 06-July-2012
1064    -------------------------
1066    1.  Fixing a wrong JIT test case and some compiler warnings.
1068    2.  Removed a bashism from the RunTest script.
1070    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1071        to unsigned type, result still unsigned" that was given by an MS compiler
1072        on encountering the code "-sizeof(xxx)".
1074    4.  Partial matching support is added to the JIT compiler.
1076    5.  Fixed several bugs concerned with partial matching of items that consist
1077        of more than one character:
1079        (a) /^(..)\1/ did not partially match "aba" because checking references was
1080            done on an "all or nothing" basis. This also applied to repeated
1081            references.
1083        (b) \R did not give a hard partial match if \r was found at the end of the
1084            subject.
1086        (c) \X did not give a hard partial match after matching one or more
1087            characters at the end of the subject.
1089        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1090            a partial match for the string "\r".
1092        (e) When newline was set to CRLF, the metacharacter "." did not recognize
1093            a partial match for a CR character at the end of the subject string.
1095    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1096        running pcretest, the text "(JIT)" added to the output whenever JIT is
1097        actually used to run the match.
1099    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
1100        or /S+[+] with a digit between 1 and 7.
1102    8.  OP_NOT now supports any UTF character not just single-byte ones.
1104    9.  (*MARK) control verb is now supported by the JIT compiler.
1106    10. The command "./RunTest list" lists the available tests without actually
1107        running any of them. (Because I keep forgetting what they all are.)
1111    12. Applied a (slightly modified) user-supplied patch that improves performance
1112        when the heap is used for recursion (compiled with --disable-stack-for-
1113        recursion). Instead of malloc and free for each heap frame each time a
1114        logical recursion happens, frames are retained on a chain and re-used where
1115        possible. This sometimes gives as much as 30% improvement.
1117    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1118        call.
1120    14. As documented, (*COMMIT) is now confined to within a positive assertion.
1122    15. It is now possible to link pcretest with libedit as an alternative to
1123        libreadline.
1125    16. (*COMMIT) control verb is now supported by the JIT compiler.
1127    17. The Unicode data tables have been updated to Unicode 6.1.0.
1129    18. Added --file-list option to pcregrep.
1131    19. Added binary file support to pcregrep, including the -a, --binary-files,
1132        -I, and --text options.
1134    20. The madvise function is renamed for posix_madvise for QNX compatibility
1135        reasons. Fixed by Giuseppe D'Angelo.
1137    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1139    22. Changed the option for creating symbolic links for 16-bit man pages from
1140        -s to -sf so that re-installing does not cause issues.
1142    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1144    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1145        matches in certain environments (the workspace was not being correctly
1146        retained). Also added to pcre_dfa_exec() a simple plausibility check on
1147        some of the workspace data at the beginning of a restart.
1149    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1150        was not doing so when it should - probably a typo introduced by SVN 528
1151        (change 8.10/14).
1153    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1154        \w+ when the character tables indicated that \x{c4} was a word character.
1155        There were several related cases, all because the tests for doing a table
1156        lookup were testing for characters less than 127 instead of 255.
1158    27. If a pattern contains capturing parentheses that are not used in a match,
1159        their slots in the ovector are set to -1. For those that are higher than
1160        any matched groups, this happens at the end of processing. In the case when
1161        there were back references that the ovector was too small to contain
1162        (causing temporary malloc'd memory to be used during matching), and the
1163        highest capturing number was not used, memory off the end of the ovector
1164        was incorrectly being set to -1. (It was using the size of the temporary
1165        memory instead of the true size.)
1167    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1168        ovector size, it uses memory at the end of the block that it has got.
1170    29. Check for an overlong MARK name and give an error at compile time. The
1171        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1173    30. JIT compiler update.
1175    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1176        Rill for the patch.
1178    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1180    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1182    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1183        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1184        was enabled.
1186    35. Improve JIT code generation for greedy plus quantifier.
1188    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1189        1 to "aa" instead of to an empty string. The bug affected repeated groups
1190        that could potentially match an empty string.
1192    37. Optimizing single character iterators in JIT.
1194    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1195        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1196        codepoints that are too big for the mode are faulted, and in a UTF mode,
1197        disallowed codepoints are also faulted.
1199    39. If PCRE was compiled with UTF support, in three places in the DFA
1200        matcher there was code that should only have been obeyed in UTF mode, but
1201        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1202        processing when bytes with values greater than 127 were present. In 16-bit
1203        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1204        both cases the values are those that cannot be the first data item in a UTF
1205        character. The three items that might have provoked this were recursions,
1206        possessively repeated groups, and atomic groups.
1208    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1209        and pcregrep, because some OS require shared objects to be explicitly
1210        passed to ld, causing the link step to fail if they are not.
1212    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1213        mode, patterns that started with \h* or \R* might be incorrectly matched.
1216    Version 8.30 04-February-2012
1217    -----------------------------
1219    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
1220        name is defined in ctype.h.
1222    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
1223        only in quite long subpatterns.
1225    3.  Removed the function pcre_info(), which has been obsolete and deprecated
1226        since it was replaced by pcre_fullinfo() in February 2000.
1228    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
1229        match a (*MARK), and the match failed at the start of the subject, a
1230        reference to memory before the start of the subject could occur. This bug
1231        was introduced by fix 17 of release 8.21.
1233    5.  A reference to an unset group with zero minimum repetition was giving
1234        totally wrong answers (in non-JavaScript-compatibility mode). For example,
1235        /(another)?(\1?)test/ matched against "hello world test". This bug was
1236        introduced in release 8.13.
1238    6.  Add support for 16-bit character strings (a large amount of work involving
1239        many changes and refactorings).
1241    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1242        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1243        from a file.
1245    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1246        rounding is not applied in this particular case).
1248    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1249        if they appear, or are escaped, in patterns.
1251    10. Get rid of a number of -Wunused-but-set-variable warnings.
1253    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1254        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1255        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1256        also returns the mark "x". This bug applied to capturing parentheses,
1257        non-capturing parentheses, and atomic parentheses. It also applied to some
1258        assertions.
1260    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1261        information out of configure.ac instead of relying on pcre.h.generic, which
1262        is not stored in the repository.
1264    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1265        -lreadline.
1267    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1269    15. Applied Graycode's patch to put the top-level frame on the stack rather
1270        than the heap when not using the stack for recursion. This gives a
1271        performance improvement in many cases when recursion is not deep.
1273    16. Experimental code added to "pcretest -C" to output the stack frame size.
1276    Version 8.21 12-Dec-2011
1277    ------------------------
1279    1.  Updating the JIT compiler.
1281    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1282        are added as well.
1284    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1285        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1286        calling _pcre_jit_exec. Some extra comments are added.
1288    4.  (*MARK) settings inside atomic groups that do not contain any capturing
1289        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1290        was introduced by change 18 for 8.20.
1292    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1293        ECMA-262 standard.
1295    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1296        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1297        This bug was probably introduced by change 9 of 8.13.
1299    7.  While fixing 6 above, I noticed that a number of other items were being
1300        incorrectly rejected as "not fixed length". This arose partly because newer
1301        opcodes had not been added to the fixed-length checking code. I have (a)
1302        corrected the bug and added tests for these items, and (b) arranged for an
1303        error to occur if an unknown opcode is encountered while checking for fixed
1304        length instead of just assuming "not fixed length". The items that were
1305        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1306        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1307        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1309    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1310        being incorrectly compiled and would have given unpredicatble results.
1312    9.  A possessively repeated subpattern with minimum repeat count greater than
1313        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1314        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1315        the first (A) could occur when it should not.
1317    10. Add a cast and remove a redundant test from the code.
1319    11. JIT should use pcre_malloc/pcre_free for allocation.
1321    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1322        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1323        is anything other than /usr, -L is still shown).
1325    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1327    14. Perl does not support \N without a following name in a [] class; PCRE now
1328        also gives an error.
1330    15. If a forward reference was repeated with an upper limit of around 2000,
1331        it caused the error "internal error: overran compiling workspace". The
1332        maximum number of forward references (including repeats) was limited by the
1333        internal workspace, and dependent on the LINK_SIZE. The code has been
1334        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1335        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1336        of around 200,000 forward references. While doing this, I also speeded up
1337        the filling in of repeated forward references.
1339    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1340        incorrectly expecting the subject to contain another "a" after the start.
1342    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1343        in the match, the SKIP should be ignored. This was not happening; instead
1344        the SKIP was being treated as NOMATCH. For patterns such as
1345        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1346        tested.
1348    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1349        now much more compatible with Perl, in particular in cases where the result
1350        is a non-match for a non-anchored pattern. For example, if
1351        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1352        "m", where previously it did not return a name. A side effect of this
1353        change is that for partial matches, the last encountered mark name is
1354        returned, as for non matches. A number of tests that were previously not
1355        Perl-compatible have been moved into the Perl-compatible test files. The
1356        refactoring has had the pleasing side effect of removing one argument from
1357        the match() function, thus reducing its stack requirements.
1359    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1360        subsequent uses of /S (without +) incorrectly behaved like /S+.
1362    21. Retrieve executable code size support for the JIT compiler and fixing
1363        some warnings.
1365    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1366        not work when the shorter character appeared right at the end of the
1367        subject string.
1369    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1370        systems.
1372    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1373        output it when the /M option is used in pcretest.
1375    25. The CheckMan script was not being included in the distribution. Also, added
1376        an explicit "perl" to run Perl scripts from the PrepareRelease script
1377        because this is reportedly needed in Windows.
1379    26. If study data was being save in a file and studying had not found a set of
1380        "starts with" bytes for the pattern, the data written to the file (though
1381        never used) was taken from uninitialized memory and so caused valgrind to
1382        complain.
1384    27. Updated RunTest.bat as provided by Sheri Pierce.
1386    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1388    29. Computation of memory usage for the table of capturing group names was
1389        giving an unnecessarily large value.
1392    Version 8.20 21-Oct-2011
1393    ------------------------
1395    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1396        a POSIX class. After further experiments with Perl, which convinced me that
1397        Perl has bugs and confusions, a closing square bracket is no longer allowed
1398        in a POSIX name. This bug also affected patterns with classes that started
1399        with full stops.
1401    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1402        captured substring, but while checking the failing first alternative,
1403        substring 1 is temporarily captured. If the output vector supplied to
1404        pcre_exec() was not big enough for this capture, the yield of the function
1405        was still zero ("insufficient space for captured substrings"). This cannot
1406        be totally fixed without adding another stack variable, which seems a lot
1407        of expense for a edge case. However, I have improved the situation in cases
1408        such as /(a)(b)x|abc/ matched against "abc", where the return code
1409        indicates that fewer than the maximum number of slots in the ovector have
1410        been set.
1412    3.  Related to (2) above: when there are more back references in a pattern than
1413        slots in the output vector, pcre_exec() uses temporary memory during
1414        matching, and copies in the captures as far as possible afterwards. It was
1415        using the entire output vector, but this conflicts with the specification
1416        that only 2/3 is used for passing back captured substrings. Now it uses
1417        only the first 2/3, for compatibility. This is, of course, another edge
1418        case.
1420    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1421        main code base, and can be used by building with --enable-jit. When this is
1422        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1423        runtime --no-jit option is given.
1425    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1426        ovector, the return from the function was zero, implying that there were
1427        other matches that did not fit. The correct "exactly full" value is now
1428        returned.
1430    6.  If a subpattern that was called recursively or as a subroutine contained
1431        (*PRUNE) or any other control that caused it to give a non-standard return,
1432        invalid errors such as "Error -26 (nested recursion at the same subject
1433        position)" or even infinite loops could occur.
1435    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1436        computing the minimum length on reaching *ACCEPT, and so ended up with the
1437        wrong value of 1 rather than 0. Further investigation indicates that
1438        computing a minimum subject length in the presence of *ACCEPT is difficult
1439        (think back references, subroutine calls), and so I have changed the code
1440        so that no minimum is registered for a pattern that contains *ACCEPT.
1442    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1443        it was not handled as intended. [But see 16 below.]
1445    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1446        Sheri Pierce.
1448    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1449        the first byte in a match must be "a".
1451    11. Change 17 for 8.13 increased the recursion depth for patterns like
1452        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1453        pattern contains any instances of (*THEN). If it does not, the old
1454        optimizations are restored. It would be nice to do this on a per-group
1455        basis, but at the moment that is not feasible.
1457    12. In some environments, the output of pcretest -C is CRLF terminated. This
1458        broke RunTest's code that checks for the link size. A single white space
1459        character after the value is now allowed for.
1461    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1462        For "fr", it uses the Windows-specific input and output files.
1464    14. If (*THEN) appeared in a group that was called recursively or as a
1465        subroutine, it did not work as intended. [But see next item.]
1467    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1468        pattern fragments (but not containing any | characters). If A and B are
1469        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1470        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1471        D. In other words, Perl considers parentheses that do not contain any |
1472        characters to be part of a surrounding alternative, whereas PCRE was
1473        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1474        differently. PCRE now behaves in the same way as Perl, except in the case
1475        of subroutine/recursion calls such as (?1) which have in any case always
1476        been different (but PCRE had them first :-).
1478    16. Related to 15 above: Perl does not treat the | in a conditional group as
1479        creating alternatives. Such a group is treated in the same way as an
1480        ordinary group without any | characters when processing (*THEN). PCRE has
1481        been changed to match Perl's behaviour.
1483    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1484        RunGrepTest script failed.
1486    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1487        inevitable for groups that contain captures, but it can lead to a lot of
1488        stack use in large patterns. The old behaviour has been restored for atomic
1489        groups that do not contain any capturing parentheses.
1491    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1492        suppress the check for a minimum subject length at run time. (If it was
1493        given to pcre_exec() or pcre_dfa_exec() it did work.)
1495    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1496        fail to work when decoding hex characters in data strings in EBCDIC
1497        environments.
1499    21. It appears that in at least one Mac OS environment, the isxdigit() function
1500        is implemented as a macro that evaluates to its argument more than once,
1501        contravening the C 90 Standard (I haven't checked a later standard). There
1502        was an instance in pcretest which caused it to go wrong when processing
1503        \x{...} escapes in subject strings. The has been rewritten to avoid using
1504        things like p++ in the argument of isxdigit().
1507    Version 8.13 16-Aug-2011
1508  ------------------------  ------------------------
1510  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 1601  Version 8.13 02-Aug-2011
1601      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
1602      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
1603      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
1604      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
1606  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
1607      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 1692  Version 8.13 02-Aug-2011
1692      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1693      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
1694      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1695      more like Perl.      more like Perl. (But see 8.20/1 above.)
1697  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
1698      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 1727  Version 8.13 02-Aug-2011
1727      (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
1728          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
1730      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1731          PCRE is built.          PCRE is built.
1733      (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 1748  Version 8.13 02-Aug-2011
1748  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
1749      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
1750      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
1752  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
1753      starting byte set, because \b was not being ignored.      starting byte set, because \b was not being ignored.
1756  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
# Line 900  Version 7.9 11-Apr-09 Line 2403  Version 7.9 11-Apr-09
2403  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
2404      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
2405      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2406      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2407        8.33.]
2409  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
2410      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 2647  Version 7.7 07-May-08
2647      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2648      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2649      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2650      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2651      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2652      was subsequently set up correctly.)      was subsequently set up correctly.)

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