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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.9 xx-xxx-09  Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
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).
14    
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).
23    
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.
28    
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().
34    
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.
38    
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.
46    
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.
55    
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().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
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.
68    
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.
72    
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.
77    
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).
86    
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.
90    
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.
95    
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.
102    
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.
106    
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
109    
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.
113    
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.
116    
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.
125    
126    
127    Version 8.12 15-Jan-2011
128    ------------------------
129    
130    1.  Fixed some typos in the markup of the man pages, and wrote a script that
131        checks for such things as part of the documentation building process.
132    
133    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
134        --match-limit and --recursion-limit options (added for 8.11). In
135        particular, this made one of the standard tests fail. (The integer value
136        went into the wrong half of a long int.)
137    
138    3.  If the --colour option was given to pcregrep with -v (invert match), it
139        did strange things, either producing crazy output, or crashing. It should,
140        of course, ignore a request for colour when reporting lines that do not
141        match.
142    
143    4.  Another pcregrep bug caused similar problems if --colour was specified with
144        -M (multiline) and the pattern match finished with a line ending.
145    
146    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
147        matched in multiline mode, the following line was shown as part of the
148        match. This seems wrong, so I have changed it.
149    
150    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
151        the check for further matches in the same line (so they could be coloured)
152        to overrun the end of the current line. If another match was found, it was
153        incorrectly shown (and then shown again when found in the next line).
154    
155    7.  If pcregrep was compiled under Windows, there was a reference to the
156        function pcregrep_exit() before it was defined. I am assuming this was
157        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
158        reported by a user. I've moved the definition above the reference.
159    
160    
161    Version 8.11 10-Dec-2010
162    ------------------------
163    
164    1.  (*THEN) was not working properly if there were untried alternatives prior
165        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
166        backtracked to try for "b" instead of moving to the next alternative branch
167        at the same level (in this case, to look for "c"). The Perl documentation
168        is clear that when (*THEN) is backtracked onto, it goes to the "next
169        alternative in the innermost enclosing group".
170    
171    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
172        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
173        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
174        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
175        (*THEN).
176    
177    3.  If \s appeared in a character class, it removed the VT character from
178        the class, even if it had been included by some previous item, for example
179        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
180        of \s, but is part of the POSIX "space" class.)
181    
182    4.  A partial match never returns an empty string (because you can always
183        match an empty string at the end of the subject); however the checking for
184        an empty string was starting at the "start of match" point. This has been
185        changed to the "earliest inspected character" point, because the returned
186        data for a partial match starts at this character. This means that, for
187        example, /(?<=abc)def/ gives a partial match for the subject "abc"
188        (previously it gave "no match").
189    
190    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
191        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
192        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
193        has an implication that the given string is incomplete (because a partial
194        match is preferred over a full match). For this reason, these items now
195        give a partial match in this situation. [Aside: previously, the one case
196        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
197        match rather than a full match, which was wrong by the old rules, but is
198        now correct.]
199    
200    6.  There was a bug in the handling of #-introduced comments, recognized when
201        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
202        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
203        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
204        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
205        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
206        places in pcre_compile().
207    
208    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
209        comments when looking ahead for named forward references to subpatterns,
210        the only newline sequence it recognized was NL. It now handles newlines
211        according to the set newline convention.
212    
213    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
214        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
215        cater for a lack of strerror(). These oversights have been fixed.
216    
217    9.  Added --match-limit and --recursion-limit to pcregrep.
218    
219    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
220    
221    11. When the -o option was used, pcregrep was setting a return code of 1, even
222        when matches were found, and --line-buffered was not being honoured.
223    
224    12. Added an optional parentheses number to the -o and --only-matching options
225        of pcregrep.
226    
227    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
228        can match an empty string. The code to do it in pcretest and pcredemo
229        needed fixing:
230    
231        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
232            only one byte after an empty string match just before CRLF (this case
233            just got forgotten; "any" and "anycrlf" were OK).
234    
235        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
236            mode when an empty string match preceded an ASCII character followed by
237            a non-ASCII character. (The code for advancing by one character rather
238            than one byte was nonsense.)
239    
240        (c) The pcredemo.c sample program did not have any code at all to handle
241            the cases when CRLF is a valid newline sequence.
242    
243    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
244        as a starting offset was within the subject string. There is now a new
245        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
246        negative or greater than the length of the string. In order to test this,
247        pcretest is extended to allow the setting of negative starting offsets.
248    
249    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
250        starting offset points to the beginning of a UTF-8 character was
251        unnecessarily clumsy. I tidied it up.
252    
253    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
254        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
255    
256    17. Nobody had reported that the --include_dir option, which was added in
257        release 7.7 should have been called --include-dir (hyphen, not underscore)
258        for compatibility with GNU grep. I have changed it to --include-dir, but
259        left --include_dir as an undocumented synonym, and the same for
260        --exclude-dir, though that is not available in GNU grep, at least as of
261        release 2.5.4.
262    
263    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
264        characters from a string of bytes) have been redefined so as not to use
265        loops, in order to improve performance in some environments. At the same
266        time, I abstracted some of the common code into auxiliary macros to save
267        repetition (this should not affect the compiled code).
268    
269    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
270        compile-time error is now given if \c is not followed by an ASCII
271        character, that is, a byte less than 128. (In EBCDIC mode, the code is
272        different, and any byte value is allowed.)
273    
274    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
275        START_OPTIMIZE option, which is now allowed at compile time - but just
276        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
277        to pcregrep and other applications that have no direct access to PCRE
278        options. The new /Y option in pcretest sets this option when calling
279        pcre_compile().
280    
281    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
282        back references. Groups containing recursive back references were forced to
283        be atomic by that change, but in the case of named groups, the amount of
284        memory required was incorrectly computed, leading to "Failed: internal
285        error: code overflow". This has been fixed.
286    
287    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
288        pcretest.c, to avoid build problems in some Borland environments.
289    
290    
291    Version 8.10 25-Jun-2010
292    ------------------------
293    
294    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
295        THEN.
296    
297    2.  (*ACCEPT) was not working when inside an atomic group.
298    
299    3.  Inside a character class, \B is treated as a literal by default, but
300        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
301        causes the error). The code is unchanged, but I tidied the documentation.
302    
303    4.  Inside a character class, PCRE always treated \R and \X as literals,
304        whereas Perl faults them if its -w option is set. I have changed PCRE so
305        that it faults them when PCRE_EXTRA is set.
306    
307    5.  Added support for \N, which always matches any character other than
308        newline. (It is the same as "." when PCRE_DOTALL is not set.)
309    
310    6.  When compiling pcregrep with newer versions of gcc which may have
311        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
312        declared with attribute warn_unused_result" were given. Just casting the
313        result to (void) does not stop the warnings; a more elaborate fudge is
314        needed. I've used a macro to implement this.
315    
316    7.  Minor change to pcretest.c to avoid a compiler warning.
317    
318    8.  Added four artifical Unicode properties to help with an option to make
319        \s etc use properties (see next item). The new properties are: Xan
320        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
321    
322    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
323        use Unicode properties. (*UCP) at the start of a pattern can be used to set
324        this option. Modified pcretest to add /W to test this facility. Added
325        REG_UCP to make it available via the POSIX interface.
326    
327    10. Added --line-buffered to pcregrep.
328    
329    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
330        studied, and the match started with a letter with a code point greater than
331        127 whose first byte was different to the first byte of the other case of
332        the letter, the other case of this starting letter was not recognized
333        (#976).
334    
335    12. If a pattern that was studied started with a repeated Unicode property
336        test, for example, \p{Nd}+, there was the theoretical possibility of
337        setting up an incorrect bitmap of starting bytes, but fortunately it could
338        not have actually happened in practice until change 8 above was made (it
339        added property types that matched character-matching opcodes).
340    
341    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
342        possible starting bytes for non-anchored patterns.
343    
344    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
345        \R, and also a number of cases that involve Unicode properties, both
346        explicit and implicit when PCRE_UCP is set.
347    
348    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
349        input, it could crash or give wrong results if characters with values
350        greater than 0xc0 were present in the subject string. (Detail: it assumed
351        UTF-8 input when processing these items.)
352    
353    16. Added a lot of (int) casts to avoid compiler warnings in systems where
354        size_t is 64-bit (#991).
355    
356    17. Added a check for running out of memory when PCRE is compiled with
357        --disable-stack-for-recursion (#990).
358    
359    18. If the last data line in a file for pcretest does not have a newline on
360        the end, a newline was missing in the output.
361    
362    19. The default pcre_chartables.c file recognizes only ASCII characters (values
363        less than 128) in its various bitmaps. However, there is a facility for
364        generating tables according to the current locale when PCRE is compiled. It
365        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
366        characters, are recognized by isspace() and therefore were getting set in
367        these tables, and indeed these tables seem to approximate to ISO 8859. This
368        caused a problem in UTF-8 mode when pcre_study() was used to create a list
369        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
370        which of course cannot start UTF-8 characters. I have changed the code so
371        that only real ASCII characters (less than 128) and the correct starting
372        bytes for UTF-8 encodings are set for characters greater than 127 when in
373        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
374        altogether.)
375    
376    20. Added the /T option to pcretest so as to be able to run tests with non-
377        standard character tables, thus making it possible to include the tests
378        used for 19 above in the standard set of tests.
379    
380    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
381        reference to a subpattern the other side of a comment that contains an
382        opening parenthesis caused either an internal compiling error, or a
383        reference to the wrong subpattern.
384    
385    
386    Version 8.02 19-Mar-2010
387    ------------------------
388    
389    1.  The Unicode data tables have been updated to Unicode 5.2.0.
390    
391    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
392        configured.
393    
394    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
395        original author of that file, following a query about its status.
396    
397    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
398        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
399    
400    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
401        quantifier applied to a forward-referencing subroutine call, could compile
402        incorrect code or give the error "internal error: previously-checked
403        referenced subpattern not found".
404    
405    6.  Both MS Visual Studio and Symbian OS have problems with initializing
406        variables to point to external functions. For these systems, therefore,
407        pcre_malloc etc. are now initialized to local functions that call the
408        relevant global functions.
409    
410    7.  There were two entries missing in the vectors called coptable and poptable
411        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
412        I've fixed the data, and added a kludgy way of testing at compile time that
413        the lengths are correct (equal to the number of opcodes).
414    
415    8.  Following on from 7, I added a similar kludge to check the length of the
416        eint vector in pcreposix.c.
417    
418    9.  Error texts for pcre_compile() are held as one long string to avoid too
419        much relocation at load time. To find a text, the string is searched,
420        counting zeros. There was no check for running off the end of the string,
421        which could happen if a new error number was added without updating the
422        string.
423    
424    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
425    
426    11. \K was not working if it appeared in an atomic group or in a group that
427        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
428        \K is "not well defined" if used in an assertion. PCRE now accepts it if
429        the assertion is positive, but not if it is negative.
430    
431    12. Change 11 fortuitously reduced the size of the stack frame used in the
432        "match()" function of pcre_exec.c by one pointer. Forthcoming
433        implementation of support for (*MARK) will need an extra pointer on the
434        stack; I have reserved it now, so that the stack frame size does not
435        decrease.
436    
437    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
438        item in branch that calls a recursion is a subroutine call - as in the
439        second branch in the above example - was incorrectly given the compile-
440        time error "recursive call could loop indefinitely" because pcre_compile()
441        was not correctly checking the subroutine for matching a non-empty string.
442    
443    14. The checks for overrunning compiling workspace could trigger after an
444        overrun had occurred. This is a "should never occur" error, but it can be
445        triggered by pathological patterns such as hundreds of nested parentheses.
446        The checks now trigger 100 bytes before the end of the workspace.
447    
448    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
449    
450    
451    Version 8.01 19-Jan-2010
452    ------------------------
453    
454    1.  If a pattern contained a conditional subpattern with only one branch (in
455        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
456        computed the wrong minimum data length (which is of course zero for such
457        subpatterns). This could cause incorrect "no match" results.
458    
459    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
460        the pattern is reset in the first branch, pcre_compile() failed with
461        "internal error: code overflow at offset...". This happened only when
462        the reset was to the original external option setting. (An optimization
463        abstracts leading options settings into an external setting, which was the
464        cause of this.)
465    
466    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
467        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
468        assertion pattern did not match (meaning that the assertion was true), it
469        was incorrectly treated as false if the SKIP had been reached during the
470        matching. This also applied to assertions used as conditions.
471    
472    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
473        assertion subpattern, including such a pattern used as a condition,
474        unpredictable results occurred, instead of the error return
475        PCRE_ERROR_DFA_UITEM.
476    
477    5.  The C++ GlobalReplace function was not working like Perl for the special
478        situation when an empty string is matched. It now does the fancy magic
479        stuff that is necessary.
480    
481    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
482        removed. (These were left over from very, very early versions of PCRE.)
483    
484    7.  Some cosmetic changes to the code to make life easier when compiling it
485        as part of something else:
486    
487        (a) Change DEBUG to PCRE_DEBUG.
488    
489        (b) In pcre_compile(), rename the member of the "branch_chain" structure
490            called "current" as "current_branch", to prevent a collision with the
491            Linux macro when compiled as a kernel module.
492    
493        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
494            prevent a collision with the Linux macro when compiled as a kernel
495            module.
496    
497    8.  In pcre_compile() there are some checks for integer overflows that used to
498        cast potentially large values to (double). This has been changed to that
499        when building, a check for int64_t is made, and if it is found, it is used
500        instead, thus avoiding the use of floating point arithmetic. (There is no
501        other use of FP in PCRE.) If int64_t is not found, the fallback is to
502        double.
503    
504    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
505        2005 (difference between two addresses compared to an unsigned value).
506    
507    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
508        custom one, because of the following reported problem in Windows:
509    
510          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
511              under Win32.
512          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
513              therefore missing the function definition.
514          - The compiler thus generates a "C" signature for the test function.
515          - The linker fails to find the "C" function.
516          - PCRE fails to configure if asked to do so against libbz2.
517    
518    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
519        messages were output:
520    
521          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
522          rerunning libtoolize, to keep the correct libtool macros in-tree.
523          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
524    
525        I have done both of these things.
526    
527    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
528        most of the time, it *can* run out if it is given a pattern that contains a
529        runaway infinite recursion. I updated the discussion in the pcrestack man
530        page.
531    
532    13. Now that we have gone to the x.xx style of version numbers, the minor
533        version may start with zero. Using 08 or 09 is a bad idea because users
534        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
535        interpreted as invalid octal numbers. I've updated the previous comment in
536        configure.ac, and also added a check that gives an error if 08 or 09 are
537        used.
538    
539    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
540        causing partial matching to fail when the end of the subject matched \W
541        in a UTF-8 pattern where \W was quantified with a minimum of 3.
542    
543    15. There were some discrepancies between the declarations in pcre_internal.h
544        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
545        their definitions. The declarations used "const uschar *" and the
546        definitions used USPTR. Even though USPTR is normally defined as "const
547        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
548        reported that: "This difference in casting confuses some C++ compilers, for
549        example, SunCC recognizes above declarations as different functions and
550        generates broken code for hbpcre." I have changed the declarations to use
551        USPTR.
552    
553    16. GNU libtool is named differently on some systems. The autogen.sh script now
554        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
555        (FreeBSD).
556    
557    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
558        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
559        comment: "Figure out how to create a longlong from a string: strtoll and
560        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
561        instance, but it only takes 2 args instead of 3!"
562    
563    18. A subtle bug concerned with back references has been fixed by a change of
564        specification, with a corresponding code fix. A pattern such as
565        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
566        refers, was giving matches when it shouldn't. For example, xa=xaaa would
567        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
568        same bug. Such groups have to be quantified to be useful, or contained
569        inside another quantified group. (If there's no repetition, the reference
570        can never match.) The problem arises because, having left the group and
571        moved on to the rest of the pattern, a later failure that backtracks into
572        the group uses the captured value from the final iteration of the group
573        rather than the correct earlier one. I have fixed this in PCRE by forcing
574        any group that contains a reference to itself to be an atomic group; that
575        is, there cannot be any backtracking into it once it has completed. This is
576        similar to recursive and subroutine calls.
577    
578    
579    Version 8.00 19-Oct-09
580    ----------------------
581    
582    1.  The table for translating pcre_compile() error codes into POSIX error codes
583        was out-of-date, and there was no check on the pcre_compile() error code
584        being within the table. This could lead to an OK return being given in
585        error.
586    
587    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
588        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
589        in a Windows environment.
590    
591    3.  The pcregrep --count option prints the count for each file even when it is
592        zero, as does GNU grep. However, pcregrep was also printing all files when
593        --files-with-matches was added. Now, when both options are given, it prints
594        counts only for those files that have at least one match. (GNU grep just
595        prints the file name in this circumstance, but including the count seems
596        more useful - otherwise, why use --count?) Also ensured that the
597        combination -clh just lists non-zero counts, with no names.
598    
599    4.  The long form of the pcregrep -F option was incorrectly implemented as
600        --fixed_strings instead of --fixed-strings. This is an incompatible change,
601        but it seems right to fix it, and I didn't think it was worth preserving
602        the old behaviour.
603    
604    5.  The command line items --regex=pattern and --regexp=pattern were not
605        recognized by pcregrep, which required --regex pattern or --regexp pattern
606        (with a space rather than an '='). The man page documented the '=' forms,
607        which are compatible with GNU grep; these now work.
608    
609    6.  No libpcreposix.pc file was created for pkg-config; there was just
610        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
611    
612    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
613        when UCP support is not needed, by modifying the Python script that
614        generates it from Unicode data files. This should not matter if the module
615        is correctly used as a library, but I received one complaint about 50K of
616        unwanted data. My guess is that the person linked everything into his
617        program rather than using a library. Anyway, it does no harm.
618    
619    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
620        was a minimum greater than 1 for a wide character in a possessive
621        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
622        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
623        character. Chaos in the form of incorrect output or a compiling loop could
624        result.
625    
626    9.  The restrictions on what a pattern can contain when partial matching is
627        requested for pcre_exec() have been removed. All patterns can now be
628        partially matched by this function. In addition, if there are at least two
629        slots in the offset vector, the offset of the earliest inspected character
630        for the match and the offset of the end of the subject are set in them when
631        PCRE_ERROR_PARTIAL is returned.
632    
633    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
634        synonymous with PCRE_PARTIAL, for backwards compatibility, and
635        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
636        and may be more useful for multi-segment matching.
637    
638    11. Partial matching with pcre_exec() is now more intuitive. A partial match
639        used to be given if ever the end of the subject was reached; now it is
640        given only if matching could not proceed because another character was
641        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
642        string "Z", which now yields "no match" instead of "partial match". In the
643        case of pcre_dfa_exec(), "no match" is given if every matching path for the
644        final character ended with (*FAIL).
645    
646    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
647        if the pattern had a "must contain" character that was already found in the
648        earlier partial match, unless partial matching was again requested. For
649        example, with the pattern /dog.(body)?/, the "must contain" character is
650        "g". If the first part-match was for the string "dog", restarting with
651        "sbody" failed. This bug has been fixed.
652    
653    13. The string returned by pcre_dfa_exec() after a partial match has been
654        changed so that it starts at the first inspected character rather than the
655        first character of the match. This makes a difference only if the pattern
656        starts with a lookbehind assertion or \b or \B (\K is not supported by
657        pcre_dfa_exec()). It's an incompatible change, but it makes the two
658        matching functions compatible, and I think it's the right thing to do.
659    
660    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
661        so that the demonstration program is easily available in environments where
662        PCRE has not been installed from source.
663    
664    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
665        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
666        library.
667    
668    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
669        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
670        is not the first non-POSIX option to be added. Clearly some people find
671        these options useful.
672    
673    17. If a caller to the POSIX matching function regexec() passes a non-zero
674        value for nmatch with a NULL value for pmatch, the value of
675        nmatch is forced to zero.
676    
677    18. RunGrepTest did not have a test for the availability of the -u option of
678        the diff command, as RunTest does. It now checks in the same way as
679        RunTest, and also checks for the -b option.
680    
681    19. If an odd number of negated classes containing just a single character
682        interposed, within parentheses, between a forward reference to a named
683        subpattern and the definition of the subpattern, compilation crashed with
684        an internal error, complaining that it could not find the referenced
685        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
686        [The bug was that it was starting one character too far in when skipping
687        over the character class, thus treating the ] as data rather than
688        terminating the class. This meant it could skip too much.]
689    
690    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
691        /g option in pcretest when the pattern contains \K, which makes it possible
692        to have an empty string match not at the start, even when the pattern is
693        anchored. Updated pcretest and pcredemo to use this option.
694    
695    21. If the maximum number of capturing subpatterns in a recursion was greater
696        than the maximum at the outer level, the higher number was returned, but
697        with unset values at the outer level. The correct (outer level) value is
698        now given.
699    
700    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
701        PCRE did not set those parentheses (unlike Perl). I have now found a way to
702        make it do so. The string so far is captured, making this feature
703        compatible with Perl.
704    
705    23. The tests have been re-organized, adding tests 11 and 12, to make it
706        possible to check the Perl 5.10 features against Perl 5.10.
707    
708    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
709        pattern matches a fixed length string. PCRE did not allow this; now it
710        does. Neither allows recursion.
711    
712    25. I finally figured out how to implement a request to provide the minimum
713        length of subject string that was needed in order to match a given pattern.
714        (It was back references and recursion that I had previously got hung up
715        on.) This code has now been added to pcre_study(); it finds a lower bound
716        to the length of subject needed. It is not necessarily the greatest lower
717        bound, but using it to avoid searching strings that are too short does give
718        some useful speed-ups. The value is available to calling programs via
719        pcre_fullinfo().
720    
721    26. While implementing 25, I discovered to my embarrassment that pcretest had
722        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
723        study optimizations had never been tested with that matching function.
724        Oops. What is worse, even when it was passed study data, there was a bug in
725        pcre_dfa_exec() that meant it never actually used it. Double oops. There
726        were also very few tests of studied patterns with pcre_dfa_exec().
727    
728    27. If (?| is used to create subpatterns with duplicate numbers, they are now
729        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
730        on the other side of the coin, they are no longer allowed to have different
731        names, because these cannot be distinguished in PCRE, and this has caused
732        confusion. (This is a difference from Perl.)
733    
734    28. When duplicate subpattern names are present (necessarily with different
735        numbers, as required by 27 above), and a test is made by name in a
736        conditional pattern, either for a subpattern having been matched, or for
737        recursion in such a pattern, all the associated numbered subpatterns are
738        tested, and the overall condition is true if the condition is true for any
739        one of them. This is the way Perl works, and is also more like the way
740        testing by number works.
741    
742    
743    Version 7.9 11-Apr-09
744  ---------------------  ---------------------
745    
746  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 17  Version 7.9 xx-xxx-09 Line 756  Version 7.9 xx-xxx-09
756      but BOOL is not.      but BOOL is not.
757    
758  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
759      PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.      PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
760    
761  4.  The pcregrep documentation said spaces were inserted as well as colons (or  4.  The pcregrep documentation said spaces were inserted as well as colons (or
762      hyphens) following file names and line numbers when outputting matching      hyphens) following file names and line numbers when outputting matching
# Line 42  Version 7.9 xx-xxx-09 Line 781  Version 7.9 xx-xxx-09
781      correctly handled. The rule now is that both the assertion and what follows      correctly handled. The rule now is that both the assertion and what follows
782      in the first alternative must satisfy the test.      in the first alternative must satisfy the test.
783    
784  9.  If auto-callout was enabled in a pattern with a conditional group whose  9.  If auto-callout was enabled in a pattern with a conditional group whose
785      condition was an assertion, PCRE could crash during matching, both with      condition was an assertion, PCRE could crash during matching, both with
786      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
787    
# Line 64  Version 7.9 xx-xxx-09 Line 803  Version 7.9 xx-xxx-09
803  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
804      from Martin Jerabek that uses macro names for all relevant character and      from Martin Jerabek that uses macro names for all relevant character and
805      string constants.      string constants.
806    
807  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
808      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
809      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
810      these, but not everybody uses configure.      these, but not everybody uses configure.
811    
812  19. A conditional group that had only one branch was not being correctly  19. A conditional group that had only one branch was not being correctly
813      recognized as an item that could match an empty string. This meant that an      recognized as an item that could match an empty string. This meant that an
814      enclosing group might also not be so recognized, causing infinite looping      enclosing group might also not be so recognized, causing infinite looping
815      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
816      with the subject "ab", where knowledge that the repeated group can match      with the subject "ab", where knowledge that the repeated group can match
817      nothing is needed in order to break the loop.      nothing is needed in order to break the loop.
818    
819  20. If a pattern that was compiled with callouts was matched using pcre_dfa_  20. If a pattern that was compiled with callouts was matched using pcre_dfa_
820      exec(), but without supplying a callout function, matching went wrong.      exec(), but without supplying a callout function, matching went wrong.
821    
822    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
823        leak if the size of the offset vector was greater than 30. When the vector
824        is smaller, the saved offsets during recursion go onto a local stack
825        vector, but for larger vectors malloc() is used. It was failing to free
826        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
827        error, in fact).
828    
829    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
830        heapframe that is used only when UTF-8 support is enabled. This caused no
831        problem, but was untidy.
832    
833    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
834        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
835        included within another project.
836    
837    24. Steven Van Ingelgem's patches to add more options to the CMake support,
838        slightly modified by me:
839    
840          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
841              not building pcregrep.
842    
843          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
844              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
845    
846    25. Forward references, both numeric and by name, in patterns that made use of
847        duplicate group numbers, could behave incorrectly or give incorrect errors,
848        because when scanning forward to find the reference group, PCRE was not
849        taking into account the duplicate group numbers. A pattern such as
850        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
851    
852    26. Changed a few more instances of "const unsigned char *" to USPTR, making
853        the feature of a custom pointer more persuasive (as requested by a user).
854    
855    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
856        pcretest.c, inside #ifndefs, because it seems they are sometimes already
857        pre-defined.
858    
859    28. Added support for (*UTF8) at the start of a pattern.
860    
861    29. Arrange for flags added by the "release type" setting in CMake to be shown
862        in the configuration summary.
863    
864    
865  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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