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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.3 09-Aug-07  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    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).
129    
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.
136    
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.
140    
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.
147    
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.
151    
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.
154    
155    28. Some minor code refactoring concerning Unicode properties and scripts
156        should reduce the stack requirement of match() slightly.
157    
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.
161    
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).
165    
166    31. A *MARK encountered during the processing of a positive assertion is now
167        recorded and passed back (compatible with Perl).
168    
169    
170    Version 8.12 15-Jan-2011
171    ------------------------
172    
173    1.  Fixed some typos in the markup of the man pages, and wrote a script that
174        checks for such things as part of the documentation building process.
175    
176    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
177        --match-limit and --recursion-limit options (added for 8.11). In
178        particular, this made one of the standard tests fail. (The integer value
179        went into the wrong half of a long int.)
180    
181    3.  If the --colour option was given to pcregrep with -v (invert match), it
182        did strange things, either producing crazy output, or crashing. It should,
183        of course, ignore a request for colour when reporting lines that do not
184        match.
185    
186    4.  Another pcregrep bug caused similar problems if --colour was specified with
187        -M (multiline) and the pattern match finished with a line ending.
188    
189    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
190        matched in multiline mode, the following line was shown as part of the
191        match. This seems wrong, so I have changed it.
192    
193    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
194        the check for further matches in the same line (so they could be coloured)
195        to overrun the end of the current line. If another match was found, it was
196        incorrectly shown (and then shown again when found in the next line).
197    
198    7.  If pcregrep was compiled under Windows, there was a reference to the
199        function pcregrep_exit() before it was defined. I am assuming this was
200        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
201        reported by a user. I've moved the definition above the reference.
202    
203    
204    Version 8.11 10-Dec-2010
205    ------------------------
206    
207    1.  (*THEN) was not working properly if there were untried alternatives prior
208        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
209        backtracked to try for "b" instead of moving to the next alternative branch
210        at the same level (in this case, to look for "c"). The Perl documentation
211        is clear that when (*THEN) is backtracked onto, it goes to the "next
212        alternative in the innermost enclosing group".
213    
214    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
215        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
216        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
217        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
218        (*THEN).
219    
220    3.  If \s appeared in a character class, it removed the VT character from
221        the class, even if it had been included by some previous item, for example
222        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
223        of \s, but is part of the POSIX "space" class.)
224    
225    4.  A partial match never returns an empty string (because you can always
226        match an empty string at the end of the subject); however the checking for
227        an empty string was starting at the "start of match" point. This has been
228        changed to the "earliest inspected character" point, because the returned
229        data for a partial match starts at this character. This means that, for
230        example, /(?<=abc)def/ gives a partial match for the subject "abc"
231        (previously it gave "no match").
232    
233    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
234        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
235        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
236        has an implication that the given string is incomplete (because a partial
237        match is preferred over a full match). For this reason, these items now
238        give a partial match in this situation. [Aside: previously, the one case
239        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
240        match rather than a full match, which was wrong by the old rules, but is
241        now correct.]
242    
243    6.  There was a bug in the handling of #-introduced comments, recognized when
244        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
245        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
246        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
247        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
248        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
249        places in pcre_compile().
250    
251    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
252        comments when looking ahead for named forward references to subpatterns,
253        the only newline sequence it recognized was NL. It now handles newlines
254        according to the set newline convention.
255    
256    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
257        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
258        cater for a lack of strerror(). These oversights have been fixed.
259    
260    9.  Added --match-limit and --recursion-limit to pcregrep.
261    
262    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
263    
264    11. When the -o option was used, pcregrep was setting a return code of 1, even
265        when matches were found, and --line-buffered was not being honoured.
266    
267    12. Added an optional parentheses number to the -o and --only-matching options
268        of pcregrep.
269    
270    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
271        can match an empty string. The code to do it in pcretest and pcredemo
272        needed fixing:
273    
274        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
275            only one byte after an empty string match just before CRLF (this case
276            just got forgotten; "any" and "anycrlf" were OK).
277    
278        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
279            mode when an empty string match preceded an ASCII character followed by
280            a non-ASCII character. (The code for advancing by one character rather
281            than one byte was nonsense.)
282    
283        (c) The pcredemo.c sample program did not have any code at all to handle
284            the cases when CRLF is a valid newline sequence.
285    
286    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
287        as a starting offset was within the subject string. There is now a new
288        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
289        negative or greater than the length of the string. In order to test this,
290        pcretest is extended to allow the setting of negative starting offsets.
291    
292    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
293        starting offset points to the beginning of a UTF-8 character was
294        unnecessarily clumsy. I tidied it up.
295    
296    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
297        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
298    
299    17. Nobody had reported that the --include_dir option, which was added in
300        release 7.7 should have been called --include-dir (hyphen, not underscore)
301        for compatibility with GNU grep. I have changed it to --include-dir, but
302        left --include_dir as an undocumented synonym, and the same for
303        --exclude-dir, though that is not available in GNU grep, at least as of
304        release 2.5.4.
305    
306    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
307        characters from a string of bytes) have been redefined so as not to use
308        loops, in order to improve performance in some environments. At the same
309        time, I abstracted some of the common code into auxiliary macros to save
310        repetition (this should not affect the compiled code).
311    
312    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
313        compile-time error is now given if \c is not followed by an ASCII
314        character, that is, a byte less than 128. (In EBCDIC mode, the code is
315        different, and any byte value is allowed.)
316    
317    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
318        START_OPTIMIZE option, which is now allowed at compile time - but just
319        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
320        to pcregrep and other applications that have no direct access to PCRE
321        options. The new /Y option in pcretest sets this option when calling
322        pcre_compile().
323    
324    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
325        back references. Groups containing recursive back references were forced to
326        be atomic by that change, but in the case of named groups, the amount of
327        memory required was incorrectly computed, leading to "Failed: internal
328        error: code overflow". This has been fixed.
329    
330    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
331        pcretest.c, to avoid build problems in some Borland environments.
332    
333    
334    Version 8.10 25-Jun-2010
335    ------------------------
336    
337    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
338        THEN.
339    
340    2.  (*ACCEPT) was not working when inside an atomic group.
341    
342    3.  Inside a character class, \B is treated as a literal by default, but
343        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
344        causes the error). The code is unchanged, but I tidied the documentation.
345    
346    4.  Inside a character class, PCRE always treated \R and \X as literals,
347        whereas Perl faults them if its -w option is set. I have changed PCRE so
348        that it faults them when PCRE_EXTRA is set.
349    
350    5.  Added support for \N, which always matches any character other than
351        newline. (It is the same as "." when PCRE_DOTALL is not set.)
352    
353    6.  When compiling pcregrep with newer versions of gcc which may have
354        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
355        declared with attribute warn_unused_result" were given. Just casting the
356        result to (void) does not stop the warnings; a more elaborate fudge is
357        needed. I've used a macro to implement this.
358    
359    7.  Minor change to pcretest.c to avoid a compiler warning.
360    
361    8.  Added four artifical Unicode properties to help with an option to make
362        \s etc use properties (see next item). The new properties are: Xan
363        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
364    
365    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
366        use Unicode properties. (*UCP) at the start of a pattern can be used to set
367        this option. Modified pcretest to add /W to test this facility. Added
368        REG_UCP to make it available via the POSIX interface.
369    
370    10. Added --line-buffered to pcregrep.
371    
372    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
373        studied, and the match started with a letter with a code point greater than
374        127 whose first byte was different to the first byte of the other case of
375        the letter, the other case of this starting letter was not recognized
376        (#976).
377    
378    12. If a pattern that was studied started with a repeated Unicode property
379        test, for example, \p{Nd}+, there was the theoretical possibility of
380        setting up an incorrect bitmap of starting bytes, but fortunately it could
381        not have actually happened in practice until change 8 above was made (it
382        added property types that matched character-matching opcodes).
383    
384    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
385        possible starting bytes for non-anchored patterns.
386    
387    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
388        \R, and also a number of cases that involve Unicode properties, both
389        explicit and implicit when PCRE_UCP is set.
390    
391    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
392        input, it could crash or give wrong results if characters with values
393        greater than 0xc0 were present in the subject string. (Detail: it assumed
394        UTF-8 input when processing these items.)
395    
396    16. Added a lot of (int) casts to avoid compiler warnings in systems where
397        size_t is 64-bit (#991).
398    
399    17. Added a check for running out of memory when PCRE is compiled with
400        --disable-stack-for-recursion (#990).
401    
402    18. If the last data line in a file for pcretest does not have a newline on
403        the end, a newline was missing in the output.
404    
405    19. The default pcre_chartables.c file recognizes only ASCII characters (values
406        less than 128) in its various bitmaps. However, there is a facility for
407        generating tables according to the current locale when PCRE is compiled. It
408        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
409        characters, are recognized by isspace() and therefore were getting set in
410        these tables, and indeed these tables seem to approximate to ISO 8859. This
411        caused a problem in UTF-8 mode when pcre_study() was used to create a list
412        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
413        which of course cannot start UTF-8 characters. I have changed the code so
414        that only real ASCII characters (less than 128) and the correct starting
415        bytes for UTF-8 encodings are set for characters greater than 127 when in
416        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
417        altogether.)
418    
419    20. Added the /T option to pcretest so as to be able to run tests with non-
420        standard character tables, thus making it possible to include the tests
421        used for 19 above in the standard set of tests.
422    
423    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
424        reference to a subpattern the other side of a comment that contains an
425        opening parenthesis caused either an internal compiling error, or a
426        reference to the wrong subpattern.
427    
428    
429    Version 8.02 19-Mar-2010
430    ------------------------
431    
432    1.  The Unicode data tables have been updated to Unicode 5.2.0.
433    
434    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
435        configured.
436    
437    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
438        original author of that file, following a query about its status.
439    
440    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
441        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
442    
443    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
444        quantifier applied to a forward-referencing subroutine call, could compile
445        incorrect code or give the error "internal error: previously-checked
446        referenced subpattern not found".
447    
448    6.  Both MS Visual Studio and Symbian OS have problems with initializing
449        variables to point to external functions. For these systems, therefore,
450        pcre_malloc etc. are now initialized to local functions that call the
451        relevant global functions.
452    
453    7.  There were two entries missing in the vectors called coptable and poptable
454        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
455        I've fixed the data, and added a kludgy way of testing at compile time that
456        the lengths are correct (equal to the number of opcodes).
457    
458    8.  Following on from 7, I added a similar kludge to check the length of the
459        eint vector in pcreposix.c.
460    
461    9.  Error texts for pcre_compile() are held as one long string to avoid too
462        much relocation at load time. To find a text, the string is searched,
463        counting zeros. There was no check for running off the end of the string,
464        which could happen if a new error number was added without updating the
465        string.
466    
467    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
468    
469    11. \K was not working if it appeared in an atomic group or in a group that
470        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
471        \K is "not well defined" if used in an assertion. PCRE now accepts it if
472        the assertion is positive, but not if it is negative.
473    
474    12. Change 11 fortuitously reduced the size of the stack frame used in the
475        "match()" function of pcre_exec.c by one pointer. Forthcoming
476        implementation of support for (*MARK) will need an extra pointer on the
477        stack; I have reserved it now, so that the stack frame size does not
478        decrease.
479    
480    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
481        item in branch that calls a recursion is a subroutine call - as in the
482        second branch in the above example - was incorrectly given the compile-
483        time error "recursive call could loop indefinitely" because pcre_compile()
484        was not correctly checking the subroutine for matching a non-empty string.
485    
486    14. The checks for overrunning compiling workspace could trigger after an
487        overrun had occurred. This is a "should never occur" error, but it can be
488        triggered by pathological patterns such as hundreds of nested parentheses.
489        The checks now trigger 100 bytes before the end of the workspace.
490    
491    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
492    
493    
494    Version 8.01 19-Jan-2010
495    ------------------------
496    
497    1.  If a pattern contained a conditional subpattern with only one branch (in
498        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
499        computed the wrong minimum data length (which is of course zero for such
500        subpatterns). This could cause incorrect "no match" results.
501    
502    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
503        the pattern is reset in the first branch, pcre_compile() failed with
504        "internal error: code overflow at offset...". This happened only when
505        the reset was to the original external option setting. (An optimization
506        abstracts leading options settings into an external setting, which was the
507        cause of this.)
508    
509    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
510        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
511        assertion pattern did not match (meaning that the assertion was true), it
512        was incorrectly treated as false if the SKIP had been reached during the
513        matching. This also applied to assertions used as conditions.
514    
515    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
516        assertion subpattern, including such a pattern used as a condition,
517        unpredictable results occurred, instead of the error return
518        PCRE_ERROR_DFA_UITEM.
519    
520    5.  The C++ GlobalReplace function was not working like Perl for the special
521        situation when an empty string is matched. It now does the fancy magic
522        stuff that is necessary.
523    
524    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
525        removed. (These were left over from very, very early versions of PCRE.)
526    
527    7.  Some cosmetic changes to the code to make life easier when compiling it
528        as part of something else:
529    
530        (a) Change DEBUG to PCRE_DEBUG.
531    
532        (b) In pcre_compile(), rename the member of the "branch_chain" structure
533            called "current" as "current_branch", to prevent a collision with the
534            Linux macro when compiled as a kernel module.
535    
536        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
537            prevent a collision with the Linux macro when compiled as a kernel
538            module.
539    
540    8.  In pcre_compile() there are some checks for integer overflows that used to
541        cast potentially large values to (double). This has been changed to that
542        when building, a check for int64_t is made, and if it is found, it is used
543        instead, thus avoiding the use of floating point arithmetic. (There is no
544        other use of FP in PCRE.) If int64_t is not found, the fallback is to
545        double.
546    
547    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
548        2005 (difference between two addresses compared to an unsigned value).
549    
550    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
551        custom one, because of the following reported problem in Windows:
552    
553          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
554              under Win32.
555          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
556              therefore missing the function definition.
557          - The compiler thus generates a "C" signature for the test function.
558          - The linker fails to find the "C" function.
559          - PCRE fails to configure if asked to do so against libbz2.
560    
561    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
562        messages were output:
563    
564          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
565          rerunning libtoolize, to keep the correct libtool macros in-tree.
566          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
567    
568        I have done both of these things.
569    
570    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
571        most of the time, it *can* run out if it is given a pattern that contains a
572        runaway infinite recursion. I updated the discussion in the pcrestack man
573        page.
574    
575    13. Now that we have gone to the x.xx style of version numbers, the minor
576        version may start with zero. Using 08 or 09 is a bad idea because users
577        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
578        interpreted as invalid octal numbers. I've updated the previous comment in
579        configure.ac, and also added a check that gives an error if 08 or 09 are
580        used.
581    
582    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
583        causing partial matching to fail when the end of the subject matched \W
584        in a UTF-8 pattern where \W was quantified with a minimum of 3.
585    
586    15. There were some discrepancies between the declarations in pcre_internal.h
587        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
588        their definitions. The declarations used "const uschar *" and the
589        definitions used USPTR. Even though USPTR is normally defined as "const
590        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
591        reported that: "This difference in casting confuses some C++ compilers, for
592        example, SunCC recognizes above declarations as different functions and
593        generates broken code for hbpcre." I have changed the declarations to use
594        USPTR.
595    
596    16. GNU libtool is named differently on some systems. The autogen.sh script now
597        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
598        (FreeBSD).
599    
600    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
601        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
602        comment: "Figure out how to create a longlong from a string: strtoll and
603        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
604        instance, but it only takes 2 args instead of 3!"
605    
606    18. A subtle bug concerned with back references has been fixed by a change of
607        specification, with a corresponding code fix. A pattern such as
608        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
609        refers, was giving matches when it shouldn't. For example, xa=xaaa would
610        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
611        same bug. Such groups have to be quantified to be useful, or contained
612        inside another quantified group. (If there's no repetition, the reference
613        can never match.) The problem arises because, having left the group and
614        moved on to the rest of the pattern, a later failure that backtracks into
615        the group uses the captured value from the final iteration of the group
616        rather than the correct earlier one. I have fixed this in PCRE by forcing
617        any group that contains a reference to itself to be an atomic group; that
618        is, there cannot be any backtracking into it once it has completed. This is
619        similar to recursive and subroutine calls.
620    
621    
622    Version 8.00 19-Oct-09
623    ----------------------
624    
625    1.  The table for translating pcre_compile() error codes into POSIX error codes
626        was out-of-date, and there was no check on the pcre_compile() error code
627        being within the table. This could lead to an OK return being given in
628        error.
629    
630    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
631        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
632        in a Windows environment.
633    
634    3.  The pcregrep --count option prints the count for each file even when it is
635        zero, as does GNU grep. However, pcregrep was also printing all files when
636        --files-with-matches was added. Now, when both options are given, it prints
637        counts only for those files that have at least one match. (GNU grep just
638        prints the file name in this circumstance, but including the count seems
639        more useful - otherwise, why use --count?) Also ensured that the
640        combination -clh just lists non-zero counts, with no names.
641    
642    4.  The long form of the pcregrep -F option was incorrectly implemented as
643        --fixed_strings instead of --fixed-strings. This is an incompatible change,
644        but it seems right to fix it, and I didn't think it was worth preserving
645        the old behaviour.
646    
647    5.  The command line items --regex=pattern and --regexp=pattern were not
648        recognized by pcregrep, which required --regex pattern or --regexp pattern
649        (with a space rather than an '='). The man page documented the '=' forms,
650        which are compatible with GNU grep; these now work.
651    
652    6.  No libpcreposix.pc file was created for pkg-config; there was just
653        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
654    
655    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
656        when UCP support is not needed, by modifying the Python script that
657        generates it from Unicode data files. This should not matter if the module
658        is correctly used as a library, but I received one complaint about 50K of
659        unwanted data. My guess is that the person linked everything into his
660        program rather than using a library. Anyway, it does no harm.
661    
662    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
663        was a minimum greater than 1 for a wide character in a possessive
664        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
665        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
666        character. Chaos in the form of incorrect output or a compiling loop could
667        result.
668    
669    9.  The restrictions on what a pattern can contain when partial matching is
670        requested for pcre_exec() have been removed. All patterns can now be
671        partially matched by this function. In addition, if there are at least two
672        slots in the offset vector, the offset of the earliest inspected character
673        for the match and the offset of the end of the subject are set in them when
674        PCRE_ERROR_PARTIAL is returned.
675    
676    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
677        synonymous with PCRE_PARTIAL, for backwards compatibility, and
678        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
679        and may be more useful for multi-segment matching.
680    
681    11. Partial matching with pcre_exec() is now more intuitive. A partial match
682        used to be given if ever the end of the subject was reached; now it is
683        given only if matching could not proceed because another character was
684        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
685        string "Z", which now yields "no match" instead of "partial match". In the
686        case of pcre_dfa_exec(), "no match" is given if every matching path for the
687        final character ended with (*FAIL).
688    
689    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
690        if the pattern had a "must contain" character that was already found in the
691        earlier partial match, unless partial matching was again requested. For
692        example, with the pattern /dog.(body)?/, the "must contain" character is
693        "g". If the first part-match was for the string "dog", restarting with
694        "sbody" failed. This bug has been fixed.
695    
696    13. The string returned by pcre_dfa_exec() after a partial match has been
697        changed so that it starts at the first inspected character rather than the
698        first character of the match. This makes a difference only if the pattern
699        starts with a lookbehind assertion or \b or \B (\K is not supported by
700        pcre_dfa_exec()). It's an incompatible change, but it makes the two
701        matching functions compatible, and I think it's the right thing to do.
702    
703    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
704        so that the demonstration program is easily available in environments where
705        PCRE has not been installed from source.
706    
707    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
708        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
709        library.
710    
711    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
712        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
713        is not the first non-POSIX option to be added. Clearly some people find
714        these options useful.
715    
716    17. If a caller to the POSIX matching function regexec() passes a non-zero
717        value for nmatch with a NULL value for pmatch, the value of
718        nmatch is forced to zero.
719    
720    18. RunGrepTest did not have a test for the availability of the -u option of
721        the diff command, as RunTest does. It now checks in the same way as
722        RunTest, and also checks for the -b option.
723    
724    19. If an odd number of negated classes containing just a single character
725        interposed, within parentheses, between a forward reference to a named
726        subpattern and the definition of the subpattern, compilation crashed with
727        an internal error, complaining that it could not find the referenced
728        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
729        [The bug was that it was starting one character too far in when skipping
730        over the character class, thus treating the ] as data rather than
731        terminating the class. This meant it could skip too much.]
732    
733    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
734        /g option in pcretest when the pattern contains \K, which makes it possible
735        to have an empty string match not at the start, even when the pattern is
736        anchored. Updated pcretest and pcredemo to use this option.
737    
738    21. If the maximum number of capturing subpatterns in a recursion was greater
739        than the maximum at the outer level, the higher number was returned, but
740        with unset values at the outer level. The correct (outer level) value is
741        now given.
742    
743    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
744        PCRE did not set those parentheses (unlike Perl). I have now found a way to
745        make it do so. The string so far is captured, making this feature
746        compatible with Perl.
747    
748    23. The tests have been re-organized, adding tests 11 and 12, to make it
749        possible to check the Perl 5.10 features against Perl 5.10.
750    
751    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
752        pattern matches a fixed length string. PCRE did not allow this; now it
753        does. Neither allows recursion.
754    
755    25. I finally figured out how to implement a request to provide the minimum
756        length of subject string that was needed in order to match a given pattern.
757        (It was back references and recursion that I had previously got hung up
758        on.) This code has now been added to pcre_study(); it finds a lower bound
759        to the length of subject needed. It is not necessarily the greatest lower
760        bound, but using it to avoid searching strings that are too short does give
761        some useful speed-ups. The value is available to calling programs via
762        pcre_fullinfo().
763    
764    26. While implementing 25, I discovered to my embarrassment that pcretest had
765        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
766        study optimizations had never been tested with that matching function.
767        Oops. What is worse, even when it was passed study data, there was a bug in
768        pcre_dfa_exec() that meant it never actually used it. Double oops. There
769        were also very few tests of studied patterns with pcre_dfa_exec().
770    
771    27. If (?| is used to create subpatterns with duplicate numbers, they are now
772        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
773        on the other side of the coin, they are no longer allowed to have different
774        names, because these cannot be distinguished in PCRE, and this has caused
775        confusion. (This is a difference from Perl.)
776    
777    28. When duplicate subpattern names are present (necessarily with different
778        numbers, as required by 27 above), and a test is made by name in a
779        conditional pattern, either for a subpattern having been matched, or for
780        recursion in such a pattern, all the associated numbered subpatterns are
781        tested, and the overall condition is true if the condition is true for any
782        one of them. This is the way Perl works, and is also more like the way
783        testing by number works.
784    
785    
786    Version 7.9 11-Apr-09
787    ---------------------
788    
789    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
790        (pcretest), all targets were linked against these libraries. This included
791        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
792        libraries. This caused unwanted dependencies to be created. This problem
793        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
794        pcretest is linked with readline.
795    
796    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
797        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
798        moved outside it again, because FALSE and TRUE are already defined in AIX,
799        but BOOL is not.
800    
801    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
802        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
803    
804    4.  The pcregrep documentation said spaces were inserted as well as colons (or
805        hyphens) following file names and line numbers when outputting matching
806        lines. This is not true; no spaces are inserted. I have also clarified the
807        wording for the --colour (or --color) option.
808    
809    5.  In pcregrep, when --colour was used with -o, the list of matching strings
810        was not coloured; this is different to GNU grep, so I have changed it to be
811        the same.
812    
813    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
814        each matching line was coloured. Now it goes on to look for further matches
815        of any of the test patterns, which is the same behaviour as GNU grep.
816    
817    7.  A pattern that could match an empty string could cause pcregrep to loop; it
818        doesn't make sense to accept an empty string match in pcregrep, so I have
819        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
820        seems to be how GNU grep behaves.
821    
822    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
823        start or after a newline", because the conditional assertion was not being
824        correctly handled. The rule now is that both the assertion and what follows
825        in the first alternative must satisfy the test.
826    
827    9.  If auto-callout was enabled in a pattern with a conditional group whose
828        condition was an assertion, PCRE could crash during matching, both with
829        pcre_exec() and pcre_dfa_exec().
830    
831    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
832        used for matching.
833    
834    11. Unicode property support in character classes was not working for
835        characters (bytes) greater than 127 when not in UTF-8 mode.
836    
837    12. Added the -M command line option to pcretest.
838    
839    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
840    
841    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
842    
843    16. Added comments and documentation about mis-use of no_arg in the C++
844        wrapper.
845    
846    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
847        from Martin Jerabek that uses macro names for all relevant character and
848        string constants.
849    
850    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
851        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
852        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
853        these, but not everybody uses configure.
854    
855    19. A conditional group that had only one branch was not being correctly
856        recognized as an item that could match an empty string. This meant that an
857        enclosing group might also not be so recognized, causing infinite looping
858        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
859        with the subject "ab", where knowledge that the repeated group can match
860        nothing is needed in order to break the loop.
861    
862    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
863        exec(), but without supplying a callout function, matching went wrong.
864    
865    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
866        leak if the size of the offset vector was greater than 30. When the vector
867        is smaller, the saved offsets during recursion go onto a local stack
868        vector, but for larger vectors malloc() is used. It was failing to free
869        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
870        error, in fact).
871    
872    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
873        heapframe that is used only when UTF-8 support is enabled. This caused no
874        problem, but was untidy.
875    
876    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
877        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
878        included within another project.
879    
880    24. Steven Van Ingelgem's patches to add more options to the CMake support,
881        slightly modified by me:
882    
883          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
884              not building pcregrep.
885    
886          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
887              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
888    
889    25. Forward references, both numeric and by name, in patterns that made use of
890        duplicate group numbers, could behave incorrectly or give incorrect errors,
891        because when scanning forward to find the reference group, PCRE was not
892        taking into account the duplicate group numbers. A pattern such as
893        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
894    
895    26. Changed a few more instances of "const unsigned char *" to USPTR, making
896        the feature of a custom pointer more persuasive (as requested by a user).
897    
898    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
899        pcretest.c, inside #ifndefs, because it seems they are sometimes already
900        pre-defined.
901    
902    28. Added support for (*UTF8) at the start of a pattern.
903    
904    29. Arrange for flags added by the "release type" setting in CMake to be shown
905        in the configuration summary.
906    
907    
908    Version 7.8 05-Sep-08
909    ---------------------
910    
911    1.  Replaced UCP searching code with optimized version as implemented for Ad
912        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
913        stage table and inline lookup instead of a function, giving speed ups of 2
914        to 5 times on some simple patterns that I tested. Permission was given to
915        distribute the MultiStage2.py script that generates the tables (it's not in
916        the tarball, but is in the Subversion repository).
917    
918    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
919        scripts.
920    
921    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
922        a group with a zero qualifier. The result of the study could be incorrect,
923        or the function might crash, depending on the pattern.
924    
925    4.  Caseless matching was not working for non-ASCII characters in back
926        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
927        It now works when Unicode Property Support is available.
928    
929    5.  In pcretest, an escape such as \x{de} in the data was always generating
930        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
931        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
932        truncation.
933    
934    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
935    
936    7.  Added two (int) casts to pcregrep when printing the difference of two
937        pointers, in case they are 64-bit values.
938    
939    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
940        test 2 if it fails.
941    
942    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
943        and a #define of that name to empty if it is not externally set. This is to
944        allow users of MSVC to set it if necessary.
945    
946    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
947        the convenience functions in the pcre_get.c source file.
948    
949    11. An option change at the start of a pattern that had top-level alternatives
950        could cause overwriting and/or a crash. This command provoked a crash in
951        some environments:
952    
953          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
954    
955        This potential security problem was recorded as CVE-2008-2371.
956    
957    12. For a pattern where the match had to start at the beginning or immediately
958        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
959        pcre_dfa_exec() could read past the end of the passed subject if there was
960        no match. To help with detecting such bugs (e.g. with valgrind), I modified
961        pcretest so that it places the subject at the end of its malloc-ed buffer.
962    
963    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
964        exec() might read past the end of the data buffer in UTF-8 mode.
965    
966    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
967        the data contained the byte 0x85 as part of a UTF-8 character within its
968        first line. This applied both to normal and DFA matching.
969    
970    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
971        /^[^d]*?$/8 failed to match "abc".
972    
973    16. Added a missing copyright notice to pcrecpp_internal.h.
974    
975    17. Make it more clear in the documentation that values returned from
976        pcre_exec() in ovector are byte offsets, not character counts.
977    
978    18. Tidied a few places to stop certain compilers from issuing warnings.
979    
980    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
981        supplied by Stefan Weber. I made a further small update for 7.8 because
982        there is a change of source arrangements: the pcre_searchfuncs.c module is
983        replaced by pcre_ucd.c.
984    
985    
986    Version 7.7 07-May-08
987    ---------------------
988    
989    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
990        a string to a long long, pretend we don't even have a long long." This is
991        done by checking for the strtoq, strtoll, and _strtoi64 functions.
992    
993    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
994        pre-7.6 versions, which defined a global no_arg variable instead of putting
995        it in the RE class. (See also #8 below.)
996    
997    3.  Remove a line of dead code, identified by coverity and reported by Nuno
998        Lopes.
999    
1000    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1001    
1002        (1) The include/exclude patterns were being applied to the whole pathnames
1003            of files, instead of just to the final components.
1004    
1005        (2) If there was more than one level of directory, the subdirectories were
1006            skipped unless they satisfied the include/exclude conditions. This is
1007            inconsistent with GNU grep (and could even be seen as contrary to the
1008            pcregrep specification - which I improved to make it absolutely clear).
1009            The action now is always to scan all levels of directory, and just
1010            apply the include/exclude patterns to regular files.
1011    
1012    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1013        --exclude_dir in the tests to avoid scanning .svn directories.
1014    
1015    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1016        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1017        doesn't support NULs in patterns.
1018    
1019    7.  Added some missing "const"s to declarations of static tables in
1020        pcre_compile.c and pcre_dfa_exec.c.
1021    
1022    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1023        caused by fix #2  above. (Subsequently also a second patch to fix the
1024        first patch. And a third patch - this was a messy problem.)
1025    
1026    9.  Applied Craig's patch to remove the use of push_back().
1027    
1028    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1029        matching function regexec().
1030    
1031    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1032        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1033        references. PCRE supports relative numbers with this syntax (I don't think
1034        Oniguruma does).
1035    
1036    12. Previously, a group with a zero repeat such as (...){0} was completely
1037        omitted from the compiled regex. However, this means that if the group
1038        was called as a subroutine from elsewhere in the pattern, things went wrong
1039        (an internal error was given). Such groups are now left in the compiled
1040        pattern, with a new opcode that causes them to be skipped at execution
1041        time.
1042    
1043    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1044        to the way PCRE behaves:
1045    
1046        (a) A lone ] character is dis-allowed (Perl treats it as data).
1047    
1048        (b) A back reference to an unmatched subpattern matches an empty string
1049            (Perl fails the current match path).
1050    
1051        (c) A data ] in a character class must be notated as \] because if the
1052            first data character in a class is ], it defines an empty class. (In
1053            Perl it is not possible to have an empty class.) The empty class []
1054            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1055            The negative empty class [^] matches any one character, independently
1056            of the DOTALL setting.
1057    
1058    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1059        non-existent subpattern following a character class starting with ']' and
1060        containing () gave an internal compiling error instead of "reference to
1061        non-existent subpattern". Fortunately, when the pattern did exist, the
1062        compiled code was correct. (When scanning forwards to check for the
1063        existencd of the subpattern, it was treating the data ']' as terminating
1064        the class, so got the count wrong. When actually compiling, the reference
1065        was subsequently set up correctly.)
1066    
1067    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1068        it was being rejected as not supported by pcre_dfa_exec(), even though
1069        other assertions are supported. I have made pcre_dfa_exec() support
1070        (*FAIL).
1071    
1072    16. The implementation of 13c above involved the invention of a new opcode,
1073        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1074        cannot be changed at match time, I realized I could make a small
1075        improvement to matching performance by compiling OP_ALLANY instead of
1076        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1077        on the OP_ANY path.
1078    
1079    17. Compiling pcretest on Windows with readline support failed without the
1080        following two fixes: (1) Make the unistd.h include conditional on
1081        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1082    
1083    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1084        ncurses library to be included for pcretest when ReadLine support is
1085        requested, but also to allow for it to be overridden. This patch came from
1086        Daniel Bergström.
1087    
1088    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1089        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1090        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1091        spotting this.
1092    
1093    
1094    Version 7.6 28-Jan-08
1095    ---------------------
1096    
1097    1.  A character class containing a very large number of characters with
1098        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1099        overflow.
1100    
1101    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1102        HAVE_LONG_LONG is not defined.
1103    
1104    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1105        bring them up to date and include new features. This patch includes:
1106    
1107        - Fixed PH's badly added libz and libbz2 support.
1108        - Fixed a problem with static linking.
1109        - Added pcredemo. [But later removed - see 7 below.]
1110        - Fixed dftables problem and added an option.
1111        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1112            HAVE_LONG_LONG.
1113        - Added readline support for pcretest.
1114        - Added an listing of the option settings after cmake has run.
1115    
1116    4.  A user submitted a patch to Makefile that makes it easy to create
1117        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1118        Makefile.am that cause it to include this special target, without
1119        affecting anything else. Note that the same mingw target plus all
1120        the other distribution libraries and programs are now supported
1121        when configuring with CMake (see 6 below) instead of with
1122        Configure/Make.
1123    
1124    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1125        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1126        exported in the Windows port". It has not yet been confirmed that the patch
1127        solves the problem, but it does no harm.
1128    
1129    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1130        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1131        with CMake, and also correct the comment about stack recursion.
1132    
1133    7.  Remove the automatic building of pcredemo from the ./configure system and
1134        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1135        of a program that users should build themselves after PCRE is installed, so
1136        building it automatically is not really right. What is more, it gave
1137        trouble in some build environments.
1138    
1139    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1140    
1141    
1142    Version 7.5 10-Jan-08
1143    ---------------------
1144    
1145    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1146        values in parens when parsing an RE using the C++ wrapper."
1147    
1148    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1149        Characters greater than 255 were excluded from the class instead of being
1150        included.
1151    
1152    3.  The same bug as (2) above applied to negated POSIX classes such as
1153        [:^space:].
1154    
1155    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1156        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1157        I have changed it.
1158    
1159    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1160        first named subpattern) and a construct such as (?&a) would reference the
1161        first named subpattern whose name started with "a" (in other words, the
1162        length check was missing). Both these problems are fixed. "Subpattern name
1163        expected" is now given for (?&) (a zero-length name), and this patch also
1164        makes it give the same error for \k'' (previously it complained that that
1165        was a reference to a non-existent subpattern).
1166    
1167    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1168        this is right because (?- can be followed by option settings as well as by
1169        digits. I have, however, made the messages clearer.
1170    
1171    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1172        than the number used in the conditional) now cause a compile-time error.
1173        This is actually not compatible with Perl, which accepts such patterns, but
1174        treats the conditional as always being FALSE (as PCRE used to), but it
1175        seems to me that giving a diagnostic is better.
1176    
1177    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1178        and messages.
1179    
1180    9.  Fix two occurrences of "backslash" in comments that should have been
1181        "backspace".
1182    
1183    10. Remove two redundant lines of code that can never be obeyed (their function
1184        was moved elsewhere).
1185    
1186    11. The program that makes PCRE's Unicode character property table had a bug
1187        which caused it to generate incorrect table entries for sequences of
1188        characters that have the same character type, but are in different scripts.
1189        It amalgamated them into a single range, with the script of the first of
1190        them. In other words, some characters were in the wrong script. There were
1191        thirteen such cases, affecting characters in the following ranges:
1192    
1193          U+002b0 - U+002c1
1194          U+0060c - U+0060d
1195          U+0061e - U+00612
1196          U+0064b - U+0065e
1197          U+0074d - U+0076d
1198          U+01800 - U+01805
1199          U+01d00 - U+01d77
1200          U+01d9b - U+01dbf
1201          U+0200b - U+0200f
1202          U+030fc - U+030fe
1203          U+03260 - U+0327f
1204          U+0fb46 - U+0fbb1
1205          U+10450 - U+1049d
1206    
1207    12. The -o option (show only the matching part of a line) for pcregrep was not
1208        compatible with GNU grep in that, if there was more than one match in a
1209        line, it showed only the first of them. It now behaves in the same way as
1210        GNU grep.
1211    
1212    13. If the -o and -v options were combined for pcregrep, it printed a blank
1213        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1214        does the same. The return code can be used to tell if there were any
1215        non-matching lines.
1216    
1217    14. Added --file-offsets and --line-offsets to pcregrep.
1218    
1219    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1220        infinitely looping recursion. The bug was that positive lookaheads were not
1221        being skipped when checking for a possible empty match (negative lookaheads
1222        and both kinds of lookbehind were skipped).
1223    
1224    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1225        inclusion of <windows.h> to before rather than after the definition of
1226        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1227    
1228    17. Specifying a possessive quantifier with a specific limit for a Unicode
1229        character property caused pcre_compile() to compile bad code, which led at
1230        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1231        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1232        caused the error; without that there was no problem.
1233    
1234    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1235    
1236    19. Added --enable-pcretest-libreadline.
1237    
1238    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1239        RE::GlobalReplace(). As a result, the number of replacements returned was
1240        double what it should be. I removed one of the increments, but Craig sent a
1241        later patch that removed the other one (the right fix) and added unit tests
1242        that check the return values (which was not done before).
1243    
1244    21. Several CMake things:
1245    
1246        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1247            the names libpcre and libpcreposix, not just pcre and pcreposix.
1248    
1249        (2) The above change means that pcretest and pcregrep are now correctly
1250            linked with the newly-built libraries, not previously installed ones.
1251    
1252        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1253    
1254    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1255        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1256        UTF-8 newline character). The key issue is that the pattern starts .*;
1257        this means that the match must be either at the beginning, or after a
1258        newline. The bug was in the code for advancing after a failed match and
1259        checking that the new position followed a newline. It was not taking
1260        account of UTF-8 characters correctly.
1261    
1262    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1263        character classes. PCRE was not treating the sequence [:...:] as a
1264        character class unless the ... were all letters. Perl, however, seems to
1265        allow any characters between [: and :], though of course it rejects as
1266        unknown any "names" that contain non-letters, because all the known class
1267        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1268        for example, whereas PCRE did not - it did not recognize a POSIX character
1269        class. This seemed a bit dangerous, so the code has been changed to be
1270        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1271        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1272        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1273        Perl does, and where it didn't before.
1274    
1275    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1276        Windows environments %n is disabled by default.
1277    
1278    
1279    Version 7.4 21-Sep-07
1280    ---------------------
1281    
1282    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1283        means that a class such as [\s] counted as "explicit reference to CR or
1284        LF". That isn't really right - the whole point of the change was to try to
1285        help when there was an actual mention of one of the two characters. So now
1286        the change happens only if \r or \n (or a literal CR or LF) character is
1287        encountered.
1288    
1289    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1290        of both had grown to the point where there were only 3 bits left.
1291        Fortunately, there was spare space in the data structure, and so I have
1292        moved the internal flags into a new 16-bit field to free up more option
1293        bits.
1294    
1295    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1296        but did not set the internal JCHANGED flag - either of these is enough to
1297        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1298        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1299        start sets both bits.
1300    
1301    4.  Added options (at build time, compile time, exec time) to change \R from
1302        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1303    
1304    5.  doc/pcresyntax.html was missing from the distribution.
1305    
1306    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1307        compatibility, even though it is no longer used.
1308    
1309    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1310        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1311        windows.h file is present (where different names are used). [This was
1312        reversed later after testing - see 16 below.]
1313    
1314    8.  Changed all #include <config.h> to #include "config.h". There were also
1315        some further <pcre.h> cases that I changed to "pcre.h".
1316    
1317    9.  When pcregrep was used with the --colour option, it missed the line ending
1318        sequence off the lines that it output.
1319    
1320    10. It was pointed out to me that arrays of string pointers cause lots of
1321        relocations when a shared library is dynamically loaded. A technique of
1322        using a single long string with a table of offsets can drastically reduce
1323        these. I have refactored PCRE in four places to do this. The result is
1324        dramatic:
1325    
1326          Originally:                          290
1327          After changing UCP table:            187
1328          After changing error message table:   43
1329          After changing table of "verbs"       36
1330          After changing table of Posix names   22
1331    
1332        Thanks to the folks working on Gregex for glib for this insight.
1333    
1334    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1335        unicode-properties was also set.
1336    
1337    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1338    
1339    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1340        checked only for CRLF.
1341    
1342    14. Added casts to pcretest.c to avoid compiler warnings.
1343    
1344    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1345    
1346    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1347        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1348        entirely. This removes changes made in 7 above.
1349    
1350    17. The CMake files have been updated, and there is now more information about
1351        building with CMake in the NON-UNIX-USE document.
1352    
1353    
1354    Version 7.3 28-Aug-07
1355  ---------------------  ---------------------
1356    
1357   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 98  Version 7.3 09-Aug-07 Line 1448  Version 7.3 09-Aug-07
1448      the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the      the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1449      full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still      full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1450      does: it's just the validity check that is more restrictive.      does: it's just the validity check that is more restrictive.
1451    
1452  16. Inserted checks for integer overflows during escape sequence (backslash)  16. Inserted checks for integer overflows during escape sequence (backslash)
1453      processing, and also fixed erroneous offset values for syntax errors during      processing, and also fixed erroneous offset values for syntax errors during
1454      backslash processing.      backslash processing.
1455    
1456  17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)  17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1457      for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".      for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1458    
1459  18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"  18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1460      caused an overrun.      caused an overrun.
1461    
1462    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1463        something other than just ASCII characters) inside a group that had an
1464        unlimited repeat caused a loop at compile time (while checking to see
1465        whether the group could match an empty string).
1466    
1467    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1468        [\P{Any}] did so. (Error in the code for printing property names.)
1469    
1470    21. An orphan \E inside a character class could cause a crash.
1471    
1472    22. A repeated capturing bracket such as (A)? could cause a wild memory
1473        reference during compilation.
1474    
1475    23. There are several functions in pcre_compile() that scan along a compiled
1476        expression for various reasons (e.g. to see if it's fixed length for look
1477        behind). There were bugs in these functions when a repeated \p or \P was
1478        present in the pattern. These operators have additional parameters compared
1479        with \d, etc, and these were not being taken into account when moving along
1480        the compiled data. Specifically:
1481    
1482        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1483            length.
1484    
1485        (b) An item such as \pL+ within a repeated group could cause crashes or
1486            loops.
1487    
1488        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1489            "reference to non-existent subpattern" error.
1490    
1491        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1492    
1493    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1494        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1495    
1496    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1497    
1498    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1499        character were causing crashes (broken optimization).
1500    
1501    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1502        \p or \P) caused a compile-time loop.
1503    
1504    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1505        break. For example, the unstudied pattern [\r\n]A does not match the string
1506        "\r\nA" because change 7.0/46 below moves the current point on by two
1507        characters after failing to match at the start. However, the pattern \nA
1508        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1509        the same is true. There doesn't seem any very clean way out of this, but
1510        what I have chosen to do makes the common cases work: PCRE now takes note
1511        of whether there can be an explicit match for \r or \n anywhere in the
1512        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1513        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1514        pattern has explicit CR or LF references.
1515    
1516    29. Added (*CR) etc for changing newline setting at start of pattern.
1517    
1518    
1519  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
1520  ---------------------  ---------------------

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