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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.4 10-Sep-07  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.
137    24. If an assertion condition captured any substrings, they were not passed
138        back unless some other capturing happened later. For example, if
139        (?(?=(a))a) was matched against "a", no capturing was returned.
141    25. When studying a pattern that contained subroutine calls or assertions,
142        the code for finding the minimum length of a possible match was handling
143        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
144        group 1 called group 2 while simultaneously a separate group 2 called group
145        1). A stack overflow occurred in this case. I have fixed this by limiting
146        the recursion depth to 10.
148    26. Updated RunTest.bat in the distribution to the version supplied by Tom
149        Fortmann. This supports explicit test numbers on the command line, and has
150        argument validation and error reporting.
152    27. An instance of \X with an unlimited repeat could fail if at any point the
153        first character it looked at was a mark character.
155    28. Some minor code refactoring concerning Unicode properties and scripts
156        should reduce the stack requirement of match() slightly.
158    29. Added the '=' option to pcretest to check the setting of unused capturing
159        slots at the end of the pattern, which are documented as being -1, but are
160        not included in the return count.
162    30. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
163        compiled something random. Now it gives a compile-time error (as does
164        Perl).
167    Version 8.12 15-Jan-2011
168    ------------------------
170    1.  Fixed some typos in the markup of the man pages, and wrote a script that
171        checks for such things as part of the documentation building process.
173    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
174        --match-limit and --recursion-limit options (added for 8.11). In
175        particular, this made one of the standard tests fail. (The integer value
176        went into the wrong half of a long int.)
178    3.  If the --colour option was given to pcregrep with -v (invert match), it
179        did strange things, either producing crazy output, or crashing. It should,
180        of course, ignore a request for colour when reporting lines that do not
181        match.
183    4.  Another pcregrep bug caused similar problems if --colour was specified with
184        -M (multiline) and the pattern match finished with a line ending.
186    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
187        matched in multiline mode, the following line was shown as part of the
188        match. This seems wrong, so I have changed it.
190    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
191        the check for further matches in the same line (so they could be coloured)
192        to overrun the end of the current line. If another match was found, it was
193        incorrectly shown (and then shown again when found in the next line).
195    7.  If pcregrep was compiled under Windows, there was a reference to the
196        function pcregrep_exit() before it was defined. I am assuming this was
197        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
198        reported by a user. I've moved the definition above the reference.
201    Version 8.11 10-Dec-2010
202    ------------------------
204    1.  (*THEN) was not working properly if there were untried alternatives prior
205        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
206        backtracked to try for "b" instead of moving to the next alternative branch
207        at the same level (in this case, to look for "c"). The Perl documentation
208        is clear that when (*THEN) is backtracked onto, it goes to the "next
209        alternative in the innermost enclosing group".
211    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
212        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
213        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
214        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
215        (*THEN).
217    3.  If \s appeared in a character class, it removed the VT character from
218        the class, even if it had been included by some previous item, for example
219        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
220        of \s, but is part of the POSIX "space" class.)
222    4.  A partial match never returns an empty string (because you can always
223        match an empty string at the end of the subject); however the checking for
224        an empty string was starting at the "start of match" point. This has been
225        changed to the "earliest inspected character" point, because the returned
226        data for a partial match starts at this character. This means that, for
227        example, /(?<=abc)def/ gives a partial match for the subject "abc"
228        (previously it gave "no match").
230    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
231        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
232        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
233        has an implication that the given string is incomplete (because a partial
234        match is preferred over a full match). For this reason, these items now
235        give a partial match in this situation. [Aside: previously, the one case
236        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
237        match rather than a full match, which was wrong by the old rules, but is
238        now correct.]
240    6.  There was a bug in the handling of #-introduced comments, recognized when
241        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
242        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
243        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
244        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
245        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
246        places in pcre_compile().
248    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
249        comments when looking ahead for named forward references to subpatterns,
250        the only newline sequence it recognized was NL. It now handles newlines
251        according to the set newline convention.
253    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
254        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
255        cater for a lack of strerror(). These oversights have been fixed.
257    9.  Added --match-limit and --recursion-limit to pcregrep.
259    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
261    11. When the -o option was used, pcregrep was setting a return code of 1, even
262        when matches were found, and --line-buffered was not being honoured.
264    12. Added an optional parentheses number to the -o and --only-matching options
265        of pcregrep.
267    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
268        can match an empty string. The code to do it in pcretest and pcredemo
269        needed fixing:
271        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
272            only one byte after an empty string match just before CRLF (this case
273            just got forgotten; "any" and "anycrlf" were OK).
275        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
276            mode when an empty string match preceded an ASCII character followed by
277            a non-ASCII character. (The code for advancing by one character rather
278            than one byte was nonsense.)
280        (c) The pcredemo.c sample program did not have any code at all to handle
281            the cases when CRLF is a valid newline sequence.
283    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
284        as a starting offset was within the subject string. There is now a new
285        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
286        negative or greater than the length of the string. In order to test this,
287        pcretest is extended to allow the setting of negative starting offsets.
289    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
290        starting offset points to the beginning of a UTF-8 character was
291        unnecessarily clumsy. I tidied it up.
293    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
294        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
296    17. Nobody had reported that the --include_dir option, which was added in
297        release 7.7 should have been called --include-dir (hyphen, not underscore)
298        for compatibility with GNU grep. I have changed it to --include-dir, but
299        left --include_dir as an undocumented synonym, and the same for
300        --exclude-dir, though that is not available in GNU grep, at least as of
301        release 2.5.4.
303    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
304        characters from a string of bytes) have been redefined so as not to use
305        loops, in order to improve performance in some environments. At the same
306        time, I abstracted some of the common code into auxiliary macros to save
307        repetition (this should not affect the compiled code).
309    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
310        compile-time error is now given if \c is not followed by an ASCII
311        character, that is, a byte less than 128. (In EBCDIC mode, the code is
312        different, and any byte value is allowed.)
314    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
315        START_OPTIMIZE option, which is now allowed at compile time - but just
316        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
317        to pcregrep and other applications that have no direct access to PCRE
318        options. The new /Y option in pcretest sets this option when calling
319        pcre_compile().
321    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
322        back references. Groups containing recursive back references were forced to
323        be atomic by that change, but in the case of named groups, the amount of
324        memory required was incorrectly computed, leading to "Failed: internal
325        error: code overflow". This has been fixed.
327    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
328        pcretest.c, to avoid build problems in some Borland environments.
331    Version 8.10 25-Jun-2010
332    ------------------------
334    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
335        THEN.
337    2.  (*ACCEPT) was not working when inside an atomic group.
339    3.  Inside a character class, \B is treated as a literal by default, but
340        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
341        causes the error). The code is unchanged, but I tidied the documentation.
343    4.  Inside a character class, PCRE always treated \R and \X as literals,
344        whereas Perl faults them if its -w option is set. I have changed PCRE so
345        that it faults them when PCRE_EXTRA is set.
347    5.  Added support for \N, which always matches any character other than
348        newline. (It is the same as "." when PCRE_DOTALL is not set.)
350    6.  When compiling pcregrep with newer versions of gcc which may have
351        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
352        declared with attribute warn_unused_result" were given. Just casting the
353        result to (void) does not stop the warnings; a more elaborate fudge is
354        needed. I've used a macro to implement this.
356    7.  Minor change to pcretest.c to avoid a compiler warning.
358    8.  Added four artifical Unicode properties to help with an option to make
359        \s etc use properties (see next item). The new properties are: Xan
360        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
362    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
363        use Unicode properties. (*UCP) at the start of a pattern can be used to set
364        this option. Modified pcretest to add /W to test this facility. Added
365        REG_UCP to make it available via the POSIX interface.
367    10. Added --line-buffered to pcregrep.
369    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
370        studied, and the match started with a letter with a code point greater than
371        127 whose first byte was different to the first byte of the other case of
372        the letter, the other case of this starting letter was not recognized
373        (#976).
375    12. If a pattern that was studied started with a repeated Unicode property
376        test, for example, \p{Nd}+, there was the theoretical possibility of
377        setting up an incorrect bitmap of starting bytes, but fortunately it could
378        not have actually happened in practice until change 8 above was made (it
379        added property types that matched character-matching opcodes).
381    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
382        possible starting bytes for non-anchored patterns.
384    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
385        \R, and also a number of cases that involve Unicode properties, both
386        explicit and implicit when PCRE_UCP is set.
388    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
389        input, it could crash or give wrong results if characters with values
390        greater than 0xc0 were present in the subject string. (Detail: it assumed
391        UTF-8 input when processing these items.)
393    16. Added a lot of (int) casts to avoid compiler warnings in systems where
394        size_t is 64-bit (#991).
396    17. Added a check for running out of memory when PCRE is compiled with
397        --disable-stack-for-recursion (#990).
399    18. If the last data line in a file for pcretest does not have a newline on
400        the end, a newline was missing in the output.
402    19. The default pcre_chartables.c file recognizes only ASCII characters (values
403        less than 128) in its various bitmaps. However, there is a facility for
404        generating tables according to the current locale when PCRE is compiled. It
405        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
406        characters, are recognized by isspace() and therefore were getting set in
407        these tables, and indeed these tables seem to approximate to ISO 8859. This
408        caused a problem in UTF-8 mode when pcre_study() was used to create a list
409        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
410        which of course cannot start UTF-8 characters. I have changed the code so
411        that only real ASCII characters (less than 128) and the correct starting
412        bytes for UTF-8 encodings are set for characters greater than 127 when in
413        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
414        altogether.)
416    20. Added the /T option to pcretest so as to be able to run tests with non-
417        standard character tables, thus making it possible to include the tests
418        used for 19 above in the standard set of tests.
420    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
421        reference to a subpattern the other side of a comment that contains an
422        opening parenthesis caused either an internal compiling error, or a
423        reference to the wrong subpattern.
426    Version 8.02 19-Mar-2010
427    ------------------------
429    1.  The Unicode data tables have been updated to Unicode 5.2.0.
431    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
432        configured.
434    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
435        original author of that file, following a query about its status.
437    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
438        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
440    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
441        quantifier applied to a forward-referencing subroutine call, could compile
442        incorrect code or give the error "internal error: previously-checked
443        referenced subpattern not found".
445    6.  Both MS Visual Studio and Symbian OS have problems with initializing
446        variables to point to external functions. For these systems, therefore,
447        pcre_malloc etc. are now initialized to local functions that call the
448        relevant global functions.
450    7.  There were two entries missing in the vectors called coptable and poptable
451        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
452        I've fixed the data, and added a kludgy way of testing at compile time that
453        the lengths are correct (equal to the number of opcodes).
455    8.  Following on from 7, I added a similar kludge to check the length of the
456        eint vector in pcreposix.c.
458    9.  Error texts for pcre_compile() are held as one long string to avoid too
459        much relocation at load time. To find a text, the string is searched,
460        counting zeros. There was no check for running off the end of the string,
461        which could happen if a new error number was added without updating the
462        string.
464    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
466    11. \K was not working if it appeared in an atomic group or in a group that
467        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
468        \K is "not well defined" if used in an assertion. PCRE now accepts it if
469        the assertion is positive, but not if it is negative.
471    12. Change 11 fortuitously reduced the size of the stack frame used in the
472        "match()" function of pcre_exec.c by one pointer. Forthcoming
473        implementation of support for (*MARK) will need an extra pointer on the
474        stack; I have reserved it now, so that the stack frame size does not
475        decrease.
477    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
478        item in branch that calls a recursion is a subroutine call - as in the
479        second branch in the above example - was incorrectly given the compile-
480        time error "recursive call could loop indefinitely" because pcre_compile()
481        was not correctly checking the subroutine for matching a non-empty string.
483    14. The checks for overrunning compiling workspace could trigger after an
484        overrun had occurred. This is a "should never occur" error, but it can be
485        triggered by pathological patterns such as hundreds of nested parentheses.
486        The checks now trigger 100 bytes before the end of the workspace.
488    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
491    Version 8.01 19-Jan-2010
492    ------------------------
494    1.  If a pattern contained a conditional subpattern with only one branch (in
495        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
496        computed the wrong minimum data length (which is of course zero for such
497        subpatterns). This could cause incorrect "no match" results.
499    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
500        the pattern is reset in the first branch, pcre_compile() failed with
501        "internal error: code overflow at offset...". This happened only when
502        the reset was to the original external option setting. (An optimization
503        abstracts leading options settings into an external setting, which was the
504        cause of this.)
506    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
507        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
508        assertion pattern did not match (meaning that the assertion was true), it
509        was incorrectly treated as false if the SKIP had been reached during the
510        matching. This also applied to assertions used as conditions.
512    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
513        assertion subpattern, including such a pattern used as a condition,
514        unpredictable results occurred, instead of the error return
517    5.  The C++ GlobalReplace function was not working like Perl for the special
518        situation when an empty string is matched. It now does the fancy magic
519        stuff that is necessary.
521    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
522        removed. (These were left over from very, very early versions of PCRE.)
524    7.  Some cosmetic changes to the code to make life easier when compiling it
525        as part of something else:
527        (a) Change DEBUG to PCRE_DEBUG.
529        (b) In pcre_compile(), rename the member of the "branch_chain" structure
530            called "current" as "current_branch", to prevent a collision with the
531            Linux macro when compiled as a kernel module.
533        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
534            prevent a collision with the Linux macro when compiled as a kernel
535            module.
537    8.  In pcre_compile() there are some checks for integer overflows that used to
538        cast potentially large values to (double). This has been changed to that
539        when building, a check for int64_t is made, and if it is found, it is used
540        instead, thus avoiding the use of floating point arithmetic. (There is no
541        other use of FP in PCRE.) If int64_t is not found, the fallback is to
542        double.
544    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
545        2005 (difference between two addresses compared to an unsigned value).
547    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
548        custom one, because of the following reported problem in Windows:
550          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
551              under Win32.
552          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
553              therefore missing the function definition.
554          - The compiler thus generates a "C" signature for the test function.
555          - The linker fails to find the "C" function.
556          - PCRE fails to configure if asked to do so against libbz2.
558    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
559        messages were output:
561          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
562          rerunning libtoolize, to keep the correct libtool macros in-tree.
563          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
565        I have done both of these things.
567    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
568        most of the time, it *can* run out if it is given a pattern that contains a
569        runaway infinite recursion. I updated the discussion in the pcrestack man
570        page.
572    13. Now that we have gone to the x.xx style of version numbers, the minor
573        version may start with zero. Using 08 or 09 is a bad idea because users
574        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
575        interpreted as invalid octal numbers. I've updated the previous comment in
576        configure.ac, and also added a check that gives an error if 08 or 09 are
577        used.
579    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
580        causing partial matching to fail when the end of the subject matched \W
581        in a UTF-8 pattern where \W was quantified with a minimum of 3.
583    15. There were some discrepancies between the declarations in pcre_internal.h
584        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
585        their definitions. The declarations used "const uschar *" and the
586        definitions used USPTR. Even though USPTR is normally defined as "const
587        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
588        reported that: "This difference in casting confuses some C++ compilers, for
589        example, SunCC recognizes above declarations as different functions and
590        generates broken code for hbpcre." I have changed the declarations to use
591        USPTR.
593    16. GNU libtool is named differently on some systems. The autogen.sh script now
594        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
595        (FreeBSD).
597    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
598        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
599        comment: "Figure out how to create a longlong from a string: strtoll and
600        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
601        instance, but it only takes 2 args instead of 3!"
603    18. A subtle bug concerned with back references has been fixed by a change of
604        specification, with a corresponding code fix. A pattern such as
605        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
606        refers, was giving matches when it shouldn't. For example, xa=xaaa would
607        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
608        same bug. Such groups have to be quantified to be useful, or contained
609        inside another quantified group. (If there's no repetition, the reference
610        can never match.) The problem arises because, having left the group and
611        moved on to the rest of the pattern, a later failure that backtracks into
612        the group uses the captured value from the final iteration of the group
613        rather than the correct earlier one. I have fixed this in PCRE by forcing
614        any group that contains a reference to itself to be an atomic group; that
615        is, there cannot be any backtracking into it once it has completed. This is
616        similar to recursive and subroutine calls.
619    Version 8.00 19-Oct-09
620    ----------------------
622    1.  The table for translating pcre_compile() error codes into POSIX error codes
623        was out-of-date, and there was no check on the pcre_compile() error code
624        being within the table. This could lead to an OK return being given in
625        error.
627    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
628        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
629        in a Windows environment.
631    3.  The pcregrep --count option prints the count for each file even when it is
632        zero, as does GNU grep. However, pcregrep was also printing all files when
633        --files-with-matches was added. Now, when both options are given, it prints
634        counts only for those files that have at least one match. (GNU grep just
635        prints the file name in this circumstance, but including the count seems
636        more useful - otherwise, why use --count?) Also ensured that the
637        combination -clh just lists non-zero counts, with no names.
639    4.  The long form of the pcregrep -F option was incorrectly implemented as
640        --fixed_strings instead of --fixed-strings. This is an incompatible change,
641        but it seems right to fix it, and I didn't think it was worth preserving
642        the old behaviour.
644    5.  The command line items --regex=pattern and --regexp=pattern were not
645        recognized by pcregrep, which required --regex pattern or --regexp pattern
646        (with a space rather than an '='). The man page documented the '=' forms,
647        which are compatible with GNU grep; these now work.
649    6.  No libpcreposix.pc file was created for pkg-config; there was just
650        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
652    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
653        when UCP support is not needed, by modifying the Python script that
654        generates it from Unicode data files. This should not matter if the module
655        is correctly used as a library, but I received one complaint about 50K of
656        unwanted data. My guess is that the person linked everything into his
657        program rather than using a library. Anyway, it does no harm.
659    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
660        was a minimum greater than 1 for a wide character in a possessive
661        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
662        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
663        character. Chaos in the form of incorrect output or a compiling loop could
664        result.
666    9.  The restrictions on what a pattern can contain when partial matching is
667        requested for pcre_exec() have been removed. All patterns can now be
668        partially matched by this function. In addition, if there are at least two
669        slots in the offset vector, the offset of the earliest inspected character
670        for the match and the offset of the end of the subject are set in them when
671        PCRE_ERROR_PARTIAL is returned.
673    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
674        synonymous with PCRE_PARTIAL, for backwards compatibility, and
675        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
676        and may be more useful for multi-segment matching.
678    11. Partial matching with pcre_exec() is now more intuitive. A partial match
679        used to be given if ever the end of the subject was reached; now it is
680        given only if matching could not proceed because another character was
681        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
682        string "Z", which now yields "no match" instead of "partial match". In the
683        case of pcre_dfa_exec(), "no match" is given if every matching path for the
684        final character ended with (*FAIL).
686    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
687        if the pattern had a "must contain" character that was already found in the
688        earlier partial match, unless partial matching was again requested. For
689        example, with the pattern /dog.(body)?/, the "must contain" character is
690        "g". If the first part-match was for the string "dog", restarting with
691        "sbody" failed. This bug has been fixed.
693    13. The string returned by pcre_dfa_exec() after a partial match has been
694        changed so that it starts at the first inspected character rather than the
695        first character of the match. This makes a difference only if the pattern
696        starts with a lookbehind assertion or \b or \B (\K is not supported by
697        pcre_dfa_exec()). It's an incompatible change, but it makes the two
698        matching functions compatible, and I think it's the right thing to do.
700    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
701        so that the demonstration program is easily available in environments where
702        PCRE has not been installed from source.
704    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
705        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
706        library.
708    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
709        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
710        is not the first non-POSIX option to be added. Clearly some people find
711        these options useful.
713    17. If a caller to the POSIX matching function regexec() passes a non-zero
714        value for nmatch with a NULL value for pmatch, the value of
715        nmatch is forced to zero.
717    18. RunGrepTest did not have a test for the availability of the -u option of
718        the diff command, as RunTest does. It now checks in the same way as
719        RunTest, and also checks for the -b option.
721    19. If an odd number of negated classes containing just a single character
722        interposed, within parentheses, between a forward reference to a named
723        subpattern and the definition of the subpattern, compilation crashed with
724        an internal error, complaining that it could not find the referenced
725        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
726        [The bug was that it was starting one character too far in when skipping
727        over the character class, thus treating the ] as data rather than
728        terminating the class. This meant it could skip too much.]
730    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
731        /g option in pcretest when the pattern contains \K, which makes it possible
732        to have an empty string match not at the start, even when the pattern is
733        anchored. Updated pcretest and pcredemo to use this option.
735    21. If the maximum number of capturing subpatterns in a recursion was greater
736        than the maximum at the outer level, the higher number was returned, but
737        with unset values at the outer level. The correct (outer level) value is
738        now given.
740    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
741        PCRE did not set those parentheses (unlike Perl). I have now found a way to
742        make it do so. The string so far is captured, making this feature
743        compatible with Perl.
745    23. The tests have been re-organized, adding tests 11 and 12, to make it
746        possible to check the Perl 5.10 features against Perl 5.10.
748    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
749        pattern matches a fixed length string. PCRE did not allow this; now it
750        does. Neither allows recursion.
752    25. I finally figured out how to implement a request to provide the minimum
753        length of subject string that was needed in order to match a given pattern.
754        (It was back references and recursion that I had previously got hung up
755        on.) This code has now been added to pcre_study(); it finds a lower bound
756        to the length of subject needed. It is not necessarily the greatest lower
757        bound, but using it to avoid searching strings that are too short does give
758        some useful speed-ups. The value is available to calling programs via
759        pcre_fullinfo().
761    26. While implementing 25, I discovered to my embarrassment that pcretest had
762        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
763        study optimizations had never been tested with that matching function.
764        Oops. What is worse, even when it was passed study data, there was a bug in
765        pcre_dfa_exec() that meant it never actually used it. Double oops. There
766        were also very few tests of studied patterns with pcre_dfa_exec().
768    27. If (?| is used to create subpatterns with duplicate numbers, they are now
769        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
770        on the other side of the coin, they are no longer allowed to have different
771        names, because these cannot be distinguished in PCRE, and this has caused
772        confusion. (This is a difference from Perl.)
774    28. When duplicate subpattern names are present (necessarily with different
775        numbers, as required by 27 above), and a test is made by name in a
776        conditional pattern, either for a subpattern having been matched, or for
777        recursion in such a pattern, all the associated numbered subpatterns are
778        tested, and the overall condition is true if the condition is true for any
779        one of them. This is the way Perl works, and is also more like the way
780        testing by number works.
783    Version 7.9 11-Apr-09
784    ---------------------
786    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
787        (pcretest), all targets were linked against these libraries. This included
788        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
789        libraries. This caused unwanted dependencies to be created. This problem
790        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
791        pcretest is linked with readline.
793    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
794        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
795        moved outside it again, because FALSE and TRUE are already defined in AIX,
796        but BOOL is not.
798    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
799        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
801    4.  The pcregrep documentation said spaces were inserted as well as colons (or
802        hyphens) following file names and line numbers when outputting matching
803        lines. This is not true; no spaces are inserted. I have also clarified the
804        wording for the --colour (or --color) option.
806    5.  In pcregrep, when --colour was used with -o, the list of matching strings
807        was not coloured; this is different to GNU grep, so I have changed it to be
808        the same.
810    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
811        each matching line was coloured. Now it goes on to look for further matches
812        of any of the test patterns, which is the same behaviour as GNU grep.
814    7.  A pattern that could match an empty string could cause pcregrep to loop; it
815        doesn't make sense to accept an empty string match in pcregrep, so I have
816        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
817        seems to be how GNU grep behaves.
819    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
820        start or after a newline", because the conditional assertion was not being
821        correctly handled. The rule now is that both the assertion and what follows
822        in the first alternative must satisfy the test.
824    9.  If auto-callout was enabled in a pattern with a conditional group whose
825        condition was an assertion, PCRE could crash during matching, both with
826        pcre_exec() and pcre_dfa_exec().
828    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
829        used for matching.
831    11. Unicode property support in character classes was not working for
832        characters (bytes) greater than 127 when not in UTF-8 mode.
834    12. Added the -M command line option to pcretest.
836    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
838    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
840    16. Added comments and documentation about mis-use of no_arg in the C++
841        wrapper.
843    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
844        from Martin Jerabek that uses macro names for all relevant character and
845        string constants.
847    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
848        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
849        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
850        these, but not everybody uses configure.
852    19. A conditional group that had only one branch was not being correctly
853        recognized as an item that could match an empty string. This meant that an
854        enclosing group might also not be so recognized, causing infinite looping
855        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
856        with the subject "ab", where knowledge that the repeated group can match
857        nothing is needed in order to break the loop.
859    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
860        exec(), but without supplying a callout function, matching went wrong.
862    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
863        leak if the size of the offset vector was greater than 30. When the vector
864        is smaller, the saved offsets during recursion go onto a local stack
865        vector, but for larger vectors malloc() is used. It was failing to free
866        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
867        error, in fact).
869    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
870        heapframe that is used only when UTF-8 support is enabled. This caused no
871        problem, but was untidy.
873    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
874        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
875        included within another project.
877    24. Steven Van Ingelgem's patches to add more options to the CMake support,
878        slightly modified by me:
880          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
881              not building pcregrep.
883          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
884              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
886    25. Forward references, both numeric and by name, in patterns that made use of
887        duplicate group numbers, could behave incorrectly or give incorrect errors,
888        because when scanning forward to find the reference group, PCRE was not
889        taking into account the duplicate group numbers. A pattern such as
890        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
892    26. Changed a few more instances of "const unsigned char *" to USPTR, making
893        the feature of a custom pointer more persuasive (as requested by a user).
895    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
896        pcretest.c, inside #ifndefs, because it seems they are sometimes already
897        pre-defined.
899    28. Added support for (*UTF8) at the start of a pattern.
901    29. Arrange for flags added by the "release type" setting in CMake to be shown
902        in the configuration summary.
905    Version 7.8 05-Sep-08
906    ---------------------
908    1.  Replaced UCP searching code with optimized version as implemented for Ad
909        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
910        stage table and inline lookup instead of a function, giving speed ups of 2
911        to 5 times on some simple patterns that I tested. Permission was given to
912        distribute the MultiStage2.py script that generates the tables (it's not in
913        the tarball, but is in the Subversion repository).
915    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
916        scripts.
918    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
919        a group with a zero qualifier. The result of the study could be incorrect,
920        or the function might crash, depending on the pattern.
922    4.  Caseless matching was not working for non-ASCII characters in back
923        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
924        It now works when Unicode Property Support is available.
926    5.  In pcretest, an escape such as \x{de} in the data was always generating
927        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
928        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
929        truncation.
931    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
933    7.  Added two (int) casts to pcregrep when printing the difference of two
934        pointers, in case they are 64-bit values.
936    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
937        test 2 if it fails.
939    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
940        and a #define of that name to empty if it is not externally set. This is to
941        allow users of MSVC to set it if necessary.
943    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
944        the convenience functions in the pcre_get.c source file.
946    11. An option change at the start of a pattern that had top-level alternatives
947        could cause overwriting and/or a crash. This command provoked a crash in
948        some environments:
950          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
952        This potential security problem was recorded as CVE-2008-2371.
954    12. For a pattern where the match had to start at the beginning or immediately
955        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
956        pcre_dfa_exec() could read past the end of the passed subject if there was
957        no match. To help with detecting such bugs (e.g. with valgrind), I modified
958        pcretest so that it places the subject at the end of its malloc-ed buffer.
960    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
961        exec() might read past the end of the data buffer in UTF-8 mode.
963    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
964        the data contained the byte 0x85 as part of a UTF-8 character within its
965        first line. This applied both to normal and DFA matching.
967    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
968        /^[^d]*?$/8 failed to match "abc".
970    16. Added a missing copyright notice to pcrecpp_internal.h.
972    17. Make it more clear in the documentation that values returned from
973        pcre_exec() in ovector are byte offsets, not character counts.
975    18. Tidied a few places to stop certain compilers from issuing warnings.
977    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
978        supplied by Stefan Weber. I made a further small update for 7.8 because
979        there is a change of source arrangements: the pcre_searchfuncs.c module is
980        replaced by pcre_ucd.c.
983    Version 7.7 07-May-08
984    ---------------------
986    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
987        a string to a long long, pretend we don't even have a long long." This is
988        done by checking for the strtoq, strtoll, and _strtoi64 functions.
990    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
991        pre-7.6 versions, which defined a global no_arg variable instead of putting
992        it in the RE class. (See also #8 below.)
994    3.  Remove a line of dead code, identified by coverity and reported by Nuno
995        Lopes.
997    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
999        (1) The include/exclude patterns were being applied to the whole pathnames
1000            of files, instead of just to the final components.
1002        (2) If there was more than one level of directory, the subdirectories were
1003            skipped unless they satisfied the include/exclude conditions. This is
1004            inconsistent with GNU grep (and could even be seen as contrary to the
1005            pcregrep specification - which I improved to make it absolutely clear).
1006            The action now is always to scan all levels of directory, and just
1007            apply the include/exclude patterns to regular files.
1009    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1010        --exclude_dir in the tests to avoid scanning .svn directories.
1012    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1013        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1014        doesn't support NULs in patterns.
1016    7.  Added some missing "const"s to declarations of static tables in
1017        pcre_compile.c and pcre_dfa_exec.c.
1019    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1020        caused by fix #2  above. (Subsequently also a second patch to fix the
1021        first patch. And a third patch - this was a messy problem.)
1023    9.  Applied Craig's patch to remove the use of push_back().
1025    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1026        matching function regexec().
1028    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1029        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1030        references. PCRE supports relative numbers with this syntax (I don't think
1031        Oniguruma does).
1033    12. Previously, a group with a zero repeat such as (...){0} was completely
1034        omitted from the compiled regex. However, this means that if the group
1035        was called as a subroutine from elsewhere in the pattern, things went wrong
1036        (an internal error was given). Such groups are now left in the compiled
1037        pattern, with a new opcode that causes them to be skipped at execution
1038        time.
1040    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1041        to the way PCRE behaves:
1043        (a) A lone ] character is dis-allowed (Perl treats it as data).
1045        (b) A back reference to an unmatched subpattern matches an empty string
1046            (Perl fails the current match path).
1048        (c) A data ] in a character class must be notated as \] because if the
1049            first data character in a class is ], it defines an empty class. (In
1050            Perl it is not possible to have an empty class.) The empty class []
1051            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1052            The negative empty class [^] matches any one character, independently
1053            of the DOTALL setting.
1055    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1056        non-existent subpattern following a character class starting with ']' and
1057        containing () gave an internal compiling error instead of "reference to
1058        non-existent subpattern". Fortunately, when the pattern did exist, the
1059        compiled code was correct. (When scanning forwards to check for the
1060        existencd of the subpattern, it was treating the data ']' as terminating
1061        the class, so got the count wrong. When actually compiling, the reference
1062        was subsequently set up correctly.)
1064    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1065        it was being rejected as not supported by pcre_dfa_exec(), even though
1066        other assertions are supported. I have made pcre_dfa_exec() support
1067        (*FAIL).
1069    16. The implementation of 13c above involved the invention of a new opcode,
1070        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1071        cannot be changed at match time, I realized I could make a small
1072        improvement to matching performance by compiling OP_ALLANY instead of
1073        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1074        on the OP_ANY path.
1076    17. Compiling pcretest on Windows with readline support failed without the
1077        following two fixes: (1) Make the unistd.h include conditional on
1078        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1080    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1081        ncurses library to be included for pcretest when ReadLine support is
1082        requested, but also to allow for it to be overridden. This patch came from
1083        Daniel Bergström.
1085    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1086        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1087        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1088        spotting this.
1091    Version 7.6 28-Jan-08
1092    ---------------------
1094    1.  A character class containing a very large number of characters with
1095        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1096        overflow.
1098    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1099        HAVE_LONG_LONG is not defined.
1101    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1102        bring them up to date and include new features. This patch includes:
1104        - Fixed PH's badly added libz and libbz2 support.
1105        - Fixed a problem with static linking.
1106        - Added pcredemo. [But later removed - see 7 below.]
1107        - Fixed dftables problem and added an option.
1108        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1109            HAVE_LONG_LONG.
1110        - Added readline support for pcretest.
1111        - Added an listing of the option settings after cmake has run.
1113    4.  A user submitted a patch to Makefile that makes it easy to create
1114        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1115        Makefile.am that cause it to include this special target, without
1116        affecting anything else. Note that the same mingw target plus all
1117        the other distribution libraries and programs are now supported
1118        when configuring with CMake (see 6 below) instead of with
1119        Configure/Make.
1121    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1122        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1123        exported in the Windows port". It has not yet been confirmed that the patch
1124        solves the problem, but it does no harm.
1126    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1127        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1128        with CMake, and also correct the comment about stack recursion.
1130    7.  Remove the automatic building of pcredemo from the ./configure system and
1131        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1132        of a program that users should build themselves after PCRE is installed, so
1133        building it automatically is not really right. What is more, it gave
1134        trouble in some build environments.
1136    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1139    Version 7.5 10-Jan-08
1140    ---------------------
1142    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1143        values in parens when parsing an RE using the C++ wrapper."
1145    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1146        Characters greater than 255 were excluded from the class instead of being
1147        included.
1149    3.  The same bug as (2) above applied to negated POSIX classes such as
1150        [:^space:].
1152    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1153        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1154        I have changed it.
1156    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1157        first named subpattern) and a construct such as (?&a) would reference the
1158        first named subpattern whose name started with "a" (in other words, the
1159        length check was missing). Both these problems are fixed. "Subpattern name
1160        expected" is now given for (?&) (a zero-length name), and this patch also
1161        makes it give the same error for \k'' (previously it complained that that
1162        was a reference to a non-existent subpattern).
1164    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1165        this is right because (?- can be followed by option settings as well as by
1166        digits. I have, however, made the messages clearer.
1168    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1169        than the number used in the conditional) now cause a compile-time error.
1170        This is actually not compatible with Perl, which accepts such patterns, but
1171        treats the conditional as always being FALSE (as PCRE used to), but it
1172        seems to me that giving a diagnostic is better.
1174    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1175        and messages.
1177    9.  Fix two occurrences of "backslash" in comments that should have been
1178        "backspace".
1180    10. Remove two redundant lines of code that can never be obeyed (their function
1181        was moved elsewhere).
1183    11. The program that makes PCRE's Unicode character property table had a bug
1184        which caused it to generate incorrect table entries for sequences of
1185        characters that have the same character type, but are in different scripts.
1186        It amalgamated them into a single range, with the script of the first of
1187        them. In other words, some characters were in the wrong script. There were
1188        thirteen such cases, affecting characters in the following ranges:
1190          U+002b0 - U+002c1
1191          U+0060c - U+0060d
1192          U+0061e - U+00612
1193          U+0064b - U+0065e
1194          U+0074d - U+0076d
1195          U+01800 - U+01805
1196          U+01d00 - U+01d77
1197          U+01d9b - U+01dbf
1198          U+0200b - U+0200f
1199          U+030fc - U+030fe
1200          U+03260 - U+0327f
1201          U+0fb46 - U+0fbb1
1202          U+10450 - U+1049d
1204    12. The -o option (show only the matching part of a line) for pcregrep was not
1205        compatible with GNU grep in that, if there was more than one match in a
1206        line, it showed only the first of them. It now behaves in the same way as
1207        GNU grep.
1209    13. If the -o and -v options were combined for pcregrep, it printed a blank
1210        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1211        does the same. The return code can be used to tell if there were any
1212        non-matching lines.
1214    14. Added --file-offsets and --line-offsets to pcregrep.
1216    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1217        infinitely looping recursion. The bug was that positive lookaheads were not
1218        being skipped when checking for a possible empty match (negative lookaheads
1219        and both kinds of lookbehind were skipped).
1221    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1222        inclusion of <windows.h> to before rather than after the definition of
1223        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1225    17. Specifying a possessive quantifier with a specific limit for a Unicode
1226        character property caused pcre_compile() to compile bad code, which led at
1227        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1228        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1229        caused the error; without that there was no problem.
1231    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1233    19. Added --enable-pcretest-libreadline.
1235    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1236        RE::GlobalReplace(). As a result, the number of replacements returned was
1237        double what it should be. I removed one of the increments, but Craig sent a
1238        later patch that removed the other one (the right fix) and added unit tests
1239        that check the return values (which was not done before).
1241    21. Several CMake things:
1243        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1244            the names libpcre and libpcreposix, not just pcre and pcreposix.
1246        (2) The above change means that pcretest and pcregrep are now correctly
1247            linked with the newly-built libraries, not previously installed ones.
1251    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1252        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1253        UTF-8 newline character). The key issue is that the pattern starts .*;
1254        this means that the match must be either at the beginning, or after a
1255        newline. The bug was in the code for advancing after a failed match and
1256        checking that the new position followed a newline. It was not taking
1257        account of UTF-8 characters correctly.
1259    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1260        character classes. PCRE was not treating the sequence [:...:] as a
1261        character class unless the ... were all letters. Perl, however, seems to
1262        allow any characters between [: and :], though of course it rejects as
1263        unknown any "names" that contain non-letters, because all the known class
1264        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1265        for example, whereas PCRE did not - it did not recognize a POSIX character
1266        class. This seemed a bit dangerous, so the code has been changed to be
1267        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1268        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1269        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1270        Perl does, and where it didn't before.
1272    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1273        Windows environments %n is disabled by default.
1276    Version 7.4 21-Sep-07
1277  ---------------------  ---------------------
1279  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1280      means that a class such as [\s] counted as "explicit reference to CR or      means that a class such as [\s] counted as "explicit reference to CR or
1281      LF". That isn't really right - the whole point of the change was to try to      LF". That isn't really right - the whole point of the change was to try to
1282      help when there was an actual mention of one of the two characters. So now      help when there was an actual mention of one of the two characters. So now
1283      the change happens only if \r or \n (or a literal CR or LF) character is      the change happens only if \r or \n (or a literal CR or LF) character is
1284      encountered.      encountered.
1286  2.  The 32-bit options word was also used for 6 internal flags, but the numbers  2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1287      of both had grown to the point where there were only 3 bits left.      of both had grown to the point where there were only 3 bits left.
1288      Fortunately, there was spare space in the data structure, and so I have      Fortunately, there was spare space in the data structure, and so I have
1289      moved the internal flags into a new 16-bit field to free up more option      moved the internal flags into a new 16-bit field to free up more option
1290      bits.      bits.
1292  3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,  3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1293      but did not set the internal JCHANGED flag - either of these is enough to      but did not set the internal JCHANGED flag - either of these is enough to
1294      control the way the "get" function works - but the PCRE_INFO_JCHANGED      control the way the "get" function works - but the PCRE_INFO_JCHANGED
1295      facility is supposed to tell if (?J) was ever used, so now (?J) at the      facility is supposed to tell if (?J) was ever used, so now (?J) at the
1296      start sets both bits.      start sets both bits.
1298    4.  Added options (at build time, compile time, exec time) to change \R from
1299        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1301    5.  doc/pcresyntax.html was missing from the distribution.
1303    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1304        compatibility, even though it is no longer used.
1306    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1307        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1308        windows.h file is present (where different names are used). [This was
1309        reversed later after testing - see 16 below.]
1311    8.  Changed all #include <config.h> to #include "config.h". There were also
1312        some further <pcre.h> cases that I changed to "pcre.h".
1314    9.  When pcregrep was used with the --colour option, it missed the line ending
1315        sequence off the lines that it output.
1317    10. It was pointed out to me that arrays of string pointers cause lots of
1318        relocations when a shared library is dynamically loaded. A technique of
1319        using a single long string with a table of offsets can drastically reduce
1320        these. I have refactored PCRE in four places to do this. The result is
1321        dramatic:
1323          Originally:                          290
1324          After changing UCP table:            187
1325          After changing error message table:   43
1326          After changing table of "verbs"       36
1327          After changing table of Posix names   22
1329        Thanks to the folks working on Gregex for glib for this insight.
1331    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1332        unicode-properties was also set.
1334    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1336    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1337        checked only for CRLF.
1339    14. Added casts to pcretest.c to avoid compiler warnings.
1341    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1343    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1344        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1345        entirely. This removes changes made in 7 above.
1347    17. The CMake files have been updated, and there is now more information about
1348        building with CMake in the NON-UNIX-USE document.
1351  Version 7.3 28-Aug-07  Version 7.3 28-Aug-07
1352  ---------------------  ---------------------

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