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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.00 ??-???-??  Version 8.13 30-Apr-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
126    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127        subject after a captured substring (to make it easier to tell which of a
128        number of identical substrings has been captured).
130    24. The way atomic groups are processed by pcre_exec() has been changed so that
131        if they are repeated, backtracking one repetition now resets captured
132        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134        "aaa". Previously, it would have been "a". As part of this code
135        refactoring, the way recursive calls are handled has also been changed.
138    Version 8.12 15-Jan-2011
139    ------------------------
141    1.  Fixed some typos in the markup of the man pages, and wrote a script that
142        checks for such things as part of the documentation building process.
144    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
145        --match-limit and --recursion-limit options (added for 8.11). In
146        particular, this made one of the standard tests fail. (The integer value
147        went into the wrong half of a long int.)
149    3.  If the --colour option was given to pcregrep with -v (invert match), it
150        did strange things, either producing crazy output, or crashing. It should,
151        of course, ignore a request for colour when reporting lines that do not
152        match.
154    4.  Another pcregrep bug caused similar problems if --colour was specified with
155        -M (multiline) and the pattern match finished with a line ending.
157    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
158        matched in multiline mode, the following line was shown as part of the
159        match. This seems wrong, so I have changed it.
161    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
162        the check for further matches in the same line (so they could be coloured)
163        to overrun the end of the current line. If another match was found, it was
164        incorrectly shown (and then shown again when found in the next line).
166    7.  If pcregrep was compiled under Windows, there was a reference to the
167        function pcregrep_exit() before it was defined. I am assuming this was
168        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
169        reported by a user. I've moved the definition above the reference.
172    Version 8.11 10-Dec-2010
173    ------------------------
175    1.  (*THEN) was not working properly if there were untried alternatives prior
176        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
177        backtracked to try for "b" instead of moving to the next alternative branch
178        at the same level (in this case, to look for "c"). The Perl documentation
179        is clear that when (*THEN) is backtracked onto, it goes to the "next
180        alternative in the innermost enclosing group".
182    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
183        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
184        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
185        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
186        (*THEN).
188    3.  If \s appeared in a character class, it removed the VT character from
189        the class, even if it had been included by some previous item, for example
190        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
191        of \s, but is part of the POSIX "space" class.)
193    4.  A partial match never returns an empty string (because you can always
194        match an empty string at the end of the subject); however the checking for
195        an empty string was starting at the "start of match" point. This has been
196        changed to the "earliest inspected character" point, because the returned
197        data for a partial match starts at this character. This means that, for
198        example, /(?<=abc)def/ gives a partial match for the subject "abc"
199        (previously it gave "no match").
201    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
202        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
203        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
204        has an implication that the given string is incomplete (because a partial
205        match is preferred over a full match). For this reason, these items now
206        give a partial match in this situation. [Aside: previously, the one case
207        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
208        match rather than a full match, which was wrong by the old rules, but is
209        now correct.]
211    6.  There was a bug in the handling of #-introduced comments, recognized when
212        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
213        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
214        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
215        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
216        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
217        places in pcre_compile().
219    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
220        comments when looking ahead for named forward references to subpatterns,
221        the only newline sequence it recognized was NL. It now handles newlines
222        according to the set newline convention.
224    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
225        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
226        cater for a lack of strerror(). These oversights have been fixed.
228    9.  Added --match-limit and --recursion-limit to pcregrep.
230    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
232    11. When the -o option was used, pcregrep was setting a return code of 1, even
233        when matches were found, and --line-buffered was not being honoured.
235    12. Added an optional parentheses number to the -o and --only-matching options
236        of pcregrep.
238    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
239        can match an empty string. The code to do it in pcretest and pcredemo
240        needed fixing:
242        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
243            only one byte after an empty string match just before CRLF (this case
244            just got forgotten; "any" and "anycrlf" were OK).
246        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
247            mode when an empty string match preceded an ASCII character followed by
248            a non-ASCII character. (The code for advancing by one character rather
249            than one byte was nonsense.)
251        (c) The pcredemo.c sample program did not have any code at all to handle
252            the cases when CRLF is a valid newline sequence.
254    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
255        as a starting offset was within the subject string. There is now a new
256        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
257        negative or greater than the length of the string. In order to test this,
258        pcretest is extended to allow the setting of negative starting offsets.
260    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
261        starting offset points to the beginning of a UTF-8 character was
262        unnecessarily clumsy. I tidied it up.
264    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
265        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
267    17. Nobody had reported that the --include_dir option, which was added in
268        release 7.7 should have been called --include-dir (hyphen, not underscore)
269        for compatibility with GNU grep. I have changed it to --include-dir, but
270        left --include_dir as an undocumented synonym, and the same for
271        --exclude-dir, though that is not available in GNU grep, at least as of
272        release 2.5.4.
274    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
275        characters from a string of bytes) have been redefined so as not to use
276        loops, in order to improve performance in some environments. At the same
277        time, I abstracted some of the common code into auxiliary macros to save
278        repetition (this should not affect the compiled code).
280    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
281        compile-time error is now given if \c is not followed by an ASCII
282        character, that is, a byte less than 128. (In EBCDIC mode, the code is
283        different, and any byte value is allowed.)
285    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
286        START_OPTIMIZE option, which is now allowed at compile time - but just
287        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
288        to pcregrep and other applications that have no direct access to PCRE
289        options. The new /Y option in pcretest sets this option when calling
290        pcre_compile().
292    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
293        back references. Groups containing recursive back references were forced to
294        be atomic by that change, but in the case of named groups, the amount of
295        memory required was incorrectly computed, leading to "Failed: internal
296        error: code overflow". This has been fixed.
298    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
299        pcretest.c, to avoid build problems in some Borland environments.
302    Version 8.10 25-Jun-2010
303    ------------------------
305    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
306        THEN.
308    2.  (*ACCEPT) was not working when inside an atomic group.
310    3.  Inside a character class, \B is treated as a literal by default, but
311        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
312        causes the error). The code is unchanged, but I tidied the documentation.
314    4.  Inside a character class, PCRE always treated \R and \X as literals,
315        whereas Perl faults them if its -w option is set. I have changed PCRE so
316        that it faults them when PCRE_EXTRA is set.
318    5.  Added support for \N, which always matches any character other than
319        newline. (It is the same as "." when PCRE_DOTALL is not set.)
321    6.  When compiling pcregrep with newer versions of gcc which may have
322        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
323        declared with attribute warn_unused_result" were given. Just casting the
324        result to (void) does not stop the warnings; a more elaborate fudge is
325        needed. I've used a macro to implement this.
327    7.  Minor change to pcretest.c to avoid a compiler warning.
329    8.  Added four artifical Unicode properties to help with an option to make
330        \s etc use properties (see next item). The new properties are: Xan
331        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
333    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
334        use Unicode properties. (*UCP) at the start of a pattern can be used to set
335        this option. Modified pcretest to add /W to test this facility. Added
336        REG_UCP to make it available via the POSIX interface.
338    10. Added --line-buffered to pcregrep.
340    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
341        studied, and the match started with a letter with a code point greater than
342        127 whose first byte was different to the first byte of the other case of
343        the letter, the other case of this starting letter was not recognized
344        (#976).
346    12. If a pattern that was studied started with a repeated Unicode property
347        test, for example, \p{Nd}+, there was the theoretical possibility of
348        setting up an incorrect bitmap of starting bytes, but fortunately it could
349        not have actually happened in practice until change 8 above was made (it
350        added property types that matched character-matching opcodes).
352    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
353        possible starting bytes for non-anchored patterns.
355    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
356        \R, and also a number of cases that involve Unicode properties, both
357        explicit and implicit when PCRE_UCP is set.
359    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
360        input, it could crash or give wrong results if characters with values
361        greater than 0xc0 were present in the subject string. (Detail: it assumed
362        UTF-8 input when processing these items.)
364    16. Added a lot of (int) casts to avoid compiler warnings in systems where
365        size_t is 64-bit (#991).
367    17. Added a check for running out of memory when PCRE is compiled with
368        --disable-stack-for-recursion (#990).
370    18. If the last data line in a file for pcretest does not have a newline on
371        the end, a newline was missing in the output.
373    19. The default pcre_chartables.c file recognizes only ASCII characters (values
374        less than 128) in its various bitmaps. However, there is a facility for
375        generating tables according to the current locale when PCRE is compiled. It
376        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
377        characters, are recognized by isspace() and therefore were getting set in
378        these tables, and indeed these tables seem to approximate to ISO 8859. This
379        caused a problem in UTF-8 mode when pcre_study() was used to create a list
380        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
381        which of course cannot start UTF-8 characters. I have changed the code so
382        that only real ASCII characters (less than 128) and the correct starting
383        bytes for UTF-8 encodings are set for characters greater than 127 when in
384        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
385        altogether.)
387    20. Added the /T option to pcretest so as to be able to run tests with non-
388        standard character tables, thus making it possible to include the tests
389        used for 19 above in the standard set of tests.
391    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
392        reference to a subpattern the other side of a comment that contains an
393        opening parenthesis caused either an internal compiling error, or a
394        reference to the wrong subpattern.
397    Version 8.02 19-Mar-2010
398    ------------------------
400    1.  The Unicode data tables have been updated to Unicode 5.2.0.
402    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
403        configured.
405    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
406        original author of that file, following a query about its status.
408    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
409        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
411    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
412        quantifier applied to a forward-referencing subroutine call, could compile
413        incorrect code or give the error "internal error: previously-checked
414        referenced subpattern not found".
416    6.  Both MS Visual Studio and Symbian OS have problems with initializing
417        variables to point to external functions. For these systems, therefore,
418        pcre_malloc etc. are now initialized to local functions that call the
419        relevant global functions.
421    7.  There were two entries missing in the vectors called coptable and poptable
422        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
423        I've fixed the data, and added a kludgy way of testing at compile time that
424        the lengths are correct (equal to the number of opcodes).
426    8.  Following on from 7, I added a similar kludge to check the length of the
427        eint vector in pcreposix.c.
429    9.  Error texts for pcre_compile() are held as one long string to avoid too
430        much relocation at load time. To find a text, the string is searched,
431        counting zeros. There was no check for running off the end of the string,
432        which could happen if a new error number was added without updating the
433        string.
435    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
437    11. \K was not working if it appeared in an atomic group or in a group that
438        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
439        \K is "not well defined" if used in an assertion. PCRE now accepts it if
440        the assertion is positive, but not if it is negative.
442    12. Change 11 fortuitously reduced the size of the stack frame used in the
443        "match()" function of pcre_exec.c by one pointer. Forthcoming
444        implementation of support for (*MARK) will need an extra pointer on the
445        stack; I have reserved it now, so that the stack frame size does not
446        decrease.
448    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
449        item in branch that calls a recursion is a subroutine call - as in the
450        second branch in the above example - was incorrectly given the compile-
451        time error "recursive call could loop indefinitely" because pcre_compile()
452        was not correctly checking the subroutine for matching a non-empty string.
454    14. The checks for overrunning compiling workspace could trigger after an
455        overrun had occurred. This is a "should never occur" error, but it can be
456        triggered by pathological patterns such as hundreds of nested parentheses.
457        The checks now trigger 100 bytes before the end of the workspace.
459    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
462    Version 8.01 19-Jan-2010
463    ------------------------
465    1.  If a pattern contained a conditional subpattern with only one branch (in
466        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
467        computed the wrong minimum data length (which is of course zero for such
468        subpatterns). This could cause incorrect "no match" results.
470    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
471        the pattern is reset in the first branch, pcre_compile() failed with
472        "internal error: code overflow at offset...". This happened only when
473        the reset was to the original external option setting. (An optimization
474        abstracts leading options settings into an external setting, which was the
475        cause of this.)
477    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
478        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
479        assertion pattern did not match (meaning that the assertion was true), it
480        was incorrectly treated as false if the SKIP had been reached during the
481        matching. This also applied to assertions used as conditions.
483    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
484        assertion subpattern, including such a pattern used as a condition,
485        unpredictable results occurred, instead of the error return
488    5.  The C++ GlobalReplace function was not working like Perl for the special
489        situation when an empty string is matched. It now does the fancy magic
490        stuff that is necessary.
492    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
493        removed. (These were left over from very, very early versions of PCRE.)
495    7.  Some cosmetic changes to the code to make life easier when compiling it
496        as part of something else:
498        (a) Change DEBUG to PCRE_DEBUG.
500        (b) In pcre_compile(), rename the member of the "branch_chain" structure
501            called "current" as "current_branch", to prevent a collision with the
502            Linux macro when compiled as a kernel module.
504        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
505            prevent a collision with the Linux macro when compiled as a kernel
506            module.
508    8.  In pcre_compile() there are some checks for integer overflows that used to
509        cast potentially large values to (double). This has been changed to that
510        when building, a check for int64_t is made, and if it is found, it is used
511        instead, thus avoiding the use of floating point arithmetic. (There is no
512        other use of FP in PCRE.) If int64_t is not found, the fallback is to
513        double.
515    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
516        2005 (difference between two addresses compared to an unsigned value).
518    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
519        custom one, because of the following reported problem in Windows:
521          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
522              under Win32.
523          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
524              therefore missing the function definition.
525          - The compiler thus generates a "C" signature for the test function.
526          - The linker fails to find the "C" function.
527          - PCRE fails to configure if asked to do so against libbz2.
529    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
530        messages were output:
532          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
533          rerunning libtoolize, to keep the correct libtool macros in-tree.
534          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
536        I have done both of these things.
538    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
539        most of the time, it *can* run out if it is given a pattern that contains a
540        runaway infinite recursion. I updated the discussion in the pcrestack man
541        page.
543    13. Now that we have gone to the x.xx style of version numbers, the minor
544        version may start with zero. Using 08 or 09 is a bad idea because users
545        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
546        interpreted as invalid octal numbers. I've updated the previous comment in
547        configure.ac, and also added a check that gives an error if 08 or 09 are
548        used.
550    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
551        causing partial matching to fail when the end of the subject matched \W
552        in a UTF-8 pattern where \W was quantified with a minimum of 3.
554    15. There were some discrepancies between the declarations in pcre_internal.h
555        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
556        their definitions. The declarations used "const uschar *" and the
557        definitions used USPTR. Even though USPTR is normally defined as "const
558        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
559        reported that: "This difference in casting confuses some C++ compilers, for
560        example, SunCC recognizes above declarations as different functions and
561        generates broken code for hbpcre." I have changed the declarations to use
562        USPTR.
564    16. GNU libtool is named differently on some systems. The autogen.sh script now
565        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
566        (FreeBSD).
568    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
569        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
570        comment: "Figure out how to create a longlong from a string: strtoll and
571        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
572        instance, but it only takes 2 args instead of 3!"
574    18. A subtle bug concerned with back references has been fixed by a change of
575        specification, with a corresponding code fix. A pattern such as
576        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
577        refers, was giving matches when it shouldn't. For example, xa=xaaa would
578        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
579        same bug. Such groups have to be quantified to be useful, or contained
580        inside another quantified group. (If there's no repetition, the reference
581        can never match.) The problem arises because, having left the group and
582        moved on to the rest of the pattern, a later failure that backtracks into
583        the group uses the captured value from the final iteration of the group
584        rather than the correct earlier one. I have fixed this in PCRE by forcing
585        any group that contains a reference to itself to be an atomic group; that
586        is, there cannot be any backtracking into it once it has completed. This is
587        similar to recursive and subroutine calls.
590    Version 8.00 19-Oct-09
591  ----------------------  ----------------------
593  1.  The table for translating pcre_compile() error codes into POSIX error codes  1.  The table for translating pcre_compile() error codes into POSIX error codes
594      was out-of-date, and there was no check on the pcre_compile() error code      was out-of-date, and there was no check on the pcre_compile() error code
595      being within the table. This could lead to an OK return being given in      being within the table. This could lead to an OK return being given in
596      error.      error.
598  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
599      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
600      in a Windows environment.      in a Windows environment.
602  3.  The pcregrep --count option prints the count for each file even when it is  3.  The pcregrep --count option prints the count for each file even when it is
603      zero, as does GNU grep. However, pcregrep was also printing all files when      zero, as does GNU grep. However, pcregrep was also printing all files when
604      --files-with-matches was added. Now, when both options are given, it prints      --files-with-matches was added. Now, when both options are given, it prints
605      counts only for those files that have at least one match. (GNU grep just      counts only for those files that have at least one match. (GNU grep just
606      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
607      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
608      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
610  4.  The long form of the pcregrep -F option was incorrectly implemented as  4.  The long form of the pcregrep -F option was incorrectly implemented as
611      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
612      but it seems right to fix it, and I didn't think it was worth preserving      but it seems right to fix it, and I didn't think it was worth preserving
613      the old behaviour.      the old behaviour.
615  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
616      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
617      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
618      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
620  6.  No libpcreposix.pc file was created for pkg-config; there was just  6.  No libpcreposix.pc file was created for pkg-config; there was just
621      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
623  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
624      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
625      generates it from Unicode data files. This should not matter if the module      generates it from Unicode data files. This should not matter if the module
626      is correctly used as a library, but I received one complaint about 50K of      is correctly used as a library, but I received one complaint about 50K of
627      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
628      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
630    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
631        was a minimum greater than 1 for a wide character in a possessive
632        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
633        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
634        character. Chaos in the form of incorrect output or a compiling loop could
635        result.
637    9.  The restrictions on what a pattern can contain when partial matching is
638        requested for pcre_exec() have been removed. All patterns can now be
639        partially matched by this function. In addition, if there are at least two
640        slots in the offset vector, the offset of the earliest inspected character
641        for the match and the offset of the end of the subject are set in them when
642        PCRE_ERROR_PARTIAL is returned.
644    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
645        synonymous with PCRE_PARTIAL, for backwards compatibility, and
646        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
647        and may be more useful for multi-segment matching.
649    11. Partial matching with pcre_exec() is now more intuitive. A partial match
650        used to be given if ever the end of the subject was reached; now it is
651        given only if matching could not proceed because another character was
652        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
653        string "Z", which now yields "no match" instead of "partial match". In the
654        case of pcre_dfa_exec(), "no match" is given if every matching path for the
655        final character ended with (*FAIL).
657    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
658        if the pattern had a "must contain" character that was already found in the
659        earlier partial match, unless partial matching was again requested. For
660        example, with the pattern /dog.(body)?/, the "must contain" character is
661        "g". If the first part-match was for the string "dog", restarting with
662        "sbody" failed. This bug has been fixed.
664    13. The string returned by pcre_dfa_exec() after a partial match has been
665        changed so that it starts at the first inspected character rather than the
666        first character of the match. This makes a difference only if the pattern
667        starts with a lookbehind assertion or \b or \B (\K is not supported by
668        pcre_dfa_exec()). It's an incompatible change, but it makes the two
669        matching functions compatible, and I think it's the right thing to do.
671    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
672        so that the demonstration program is easily available in environments where
673        PCRE has not been installed from source.
675    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
676        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
677        library.
679    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
680        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
681        is not the first non-POSIX option to be added. Clearly some people find
682        these options useful.
684    17. If a caller to the POSIX matching function regexec() passes a non-zero
685        value for nmatch with a NULL value for pmatch, the value of
686        nmatch is forced to zero.
688    18. RunGrepTest did not have a test for the availability of the -u option of
689        the diff command, as RunTest does. It now checks in the same way as
690        RunTest, and also checks for the -b option.
692    19. If an odd number of negated classes containing just a single character
693        interposed, within parentheses, between a forward reference to a named
694        subpattern and the definition of the subpattern, compilation crashed with
695        an internal error, complaining that it could not find the referenced
696        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
697        [The bug was that it was starting one character too far in when skipping
698        over the character class, thus treating the ] as data rather than
699        terminating the class. This meant it could skip too much.]
701    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
702        /g option in pcretest when the pattern contains \K, which makes it possible
703        to have an empty string match not at the start, even when the pattern is
704        anchored. Updated pcretest and pcredemo to use this option.
706    21. If the maximum number of capturing subpatterns in a recursion was greater
707        than the maximum at the outer level, the higher number was returned, but
708        with unset values at the outer level. The correct (outer level) value is
709        now given.
711    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
712        PCRE did not set those parentheses (unlike Perl). I have now found a way to
713        make it do so. The string so far is captured, making this feature
714        compatible with Perl.
716    23. The tests have been re-organized, adding tests 11 and 12, to make it
717        possible to check the Perl 5.10 features against Perl 5.10.
719    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
720        pattern matches a fixed length string. PCRE did not allow this; now it
721        does. Neither allows recursion.
723    25. I finally figured out how to implement a request to provide the minimum
724        length of subject string that was needed in order to match a given pattern.
725        (It was back references and recursion that I had previously got hung up
726        on.) This code has now been added to pcre_study(); it finds a lower bound
727        to the length of subject needed. It is not necessarily the greatest lower
728        bound, but using it to avoid searching strings that are too short does give
729        some useful speed-ups. The value is available to calling programs via
730        pcre_fullinfo().
732    26. While implementing 25, I discovered to my embarrassment that pcretest had
733        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
734        study optimizations had never been tested with that matching function.
735        Oops. What is worse, even when it was passed study data, there was a bug in
736        pcre_dfa_exec() that meant it never actually used it. Double oops. There
737        were also very few tests of studied patterns with pcre_dfa_exec().
739    27. If (?| is used to create subpatterns with duplicate numbers, they are now
740        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
741        on the other side of the coin, they are no longer allowed to have different
742        names, because these cannot be distinguished in PCRE, and this has caused
743        confusion. (This is a difference from Perl.)
745    28. When duplicate subpattern names are present (necessarily with different
746        numbers, as required by 27 above), and a test is made by name in a
747        conditional pattern, either for a subpattern having been matched, or for
748        recursion in such a pattern, all the associated numbered subpatterns are
749        tested, and the overall condition is true if the condition is true for any
750        one of them. This is the way Perl works, and is also more like the way
751        testing by number works.
754  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
755  ---------------------  ---------------------

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