/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 284 by ph10, Fri Dec 7 20:01:16 2007 UTC revision 618 by ph10, Sat Jul 16 17:24:16 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 12-Nov-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    
138    Version 8.12 15-Jan-2011
139    ------------------------
140    
141    1.  Fixed some typos in the markup of the man pages, and wrote a script that
142        checks for such things as part of the documentation building process.
143    
144    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
145        --match-limit and --recursion-limit options (added for 8.11). In
146        particular, this made one of the standard tests fail. (The integer value
147        went into the wrong half of a long int.)
148    
149    3.  If the --colour option was given to pcregrep with -v (invert match), it
150        did strange things, either producing crazy output, or crashing. It should,
151        of course, ignore a request for colour when reporting lines that do not
152        match.
153    
154    4.  Another pcregrep bug caused similar problems if --colour was specified with
155        -M (multiline) and the pattern match finished with a line ending.
156    
157    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
158        matched in multiline mode, the following line was shown as part of the
159        match. This seems wrong, so I have changed it.
160    
161    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
162        the check for further matches in the same line (so they could be coloured)
163        to overrun the end of the current line. If another match was found, it was
164        incorrectly shown (and then shown again when found in the next line).
165    
166    7.  If pcregrep was compiled under Windows, there was a reference to the
167        function pcregrep_exit() before it was defined. I am assuming this was
168        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
169        reported by a user. I've moved the definition above the reference.
170    
171    
172    Version 8.11 10-Dec-2010
173    ------------------------
174    
175    1.  (*THEN) was not working properly if there were untried alternatives prior
176        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
177        backtracked to try for "b" instead of moving to the next alternative branch
178        at the same level (in this case, to look for "c"). The Perl documentation
179        is clear that when (*THEN) is backtracked onto, it goes to the "next
180        alternative in the innermost enclosing group".
181    
182    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
183        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
184        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
185        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
186        (*THEN).
187    
188    3.  If \s appeared in a character class, it removed the VT character from
189        the class, even if it had been included by some previous item, for example
190        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
191        of \s, but is part of the POSIX "space" class.)
192    
193    4.  A partial match never returns an empty string (because you can always
194        match an empty string at the end of the subject); however the checking for
195        an empty string was starting at the "start of match" point. This has been
196        changed to the "earliest inspected character" point, because the returned
197        data for a partial match starts at this character. This means that, for
198        example, /(?<=abc)def/ gives a partial match for the subject "abc"
199        (previously it gave "no match").
200    
201    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
202        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
203        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
204        has an implication that the given string is incomplete (because a partial
205        match is preferred over a full match). For this reason, these items now
206        give a partial match in this situation. [Aside: previously, the one case
207        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
208        match rather than a full match, which was wrong by the old rules, but is
209        now correct.]
210    
211    6.  There was a bug in the handling of #-introduced comments, recognized when
212        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
213        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
214        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
215        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
216        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
217        places in pcre_compile().
218    
219    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
220        comments when looking ahead for named forward references to subpatterns,
221        the only newline sequence it recognized was NL. It now handles newlines
222        according to the set newline convention.
223    
224    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
225        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
226        cater for a lack of strerror(). These oversights have been fixed.
227    
228    9.  Added --match-limit and --recursion-limit to pcregrep.
229    
230    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
231    
232    11. When the -o option was used, pcregrep was setting a return code of 1, even
233        when matches were found, and --line-buffered was not being honoured.
234    
235    12. Added an optional parentheses number to the -o and --only-matching options
236        of pcregrep.
237    
238    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
239        can match an empty string. The code to do it in pcretest and pcredemo
240        needed fixing:
241    
242        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
243            only one byte after an empty string match just before CRLF (this case
244            just got forgotten; "any" and "anycrlf" were OK).
245    
246        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
247            mode when an empty string match preceded an ASCII character followed by
248            a non-ASCII character. (The code for advancing by one character rather
249            than one byte was nonsense.)
250    
251        (c) The pcredemo.c sample program did not have any code at all to handle
252            the cases when CRLF is a valid newline sequence.
253    
254    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
255        as a starting offset was within the subject string. There is now a new
256        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
257        negative or greater than the length of the string. In order to test this,
258        pcretest is extended to allow the setting of negative starting offsets.
259    
260    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
261        starting offset points to the beginning of a UTF-8 character was
262        unnecessarily clumsy. I tidied it up.
263    
264    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
265        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
266    
267    17. Nobody had reported that the --include_dir option, which was added in
268        release 7.7 should have been called --include-dir (hyphen, not underscore)
269        for compatibility with GNU grep. I have changed it to --include-dir, but
270        left --include_dir as an undocumented synonym, and the same for
271        --exclude-dir, though that is not available in GNU grep, at least as of
272        release 2.5.4.
273    
274    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
275        characters from a string of bytes) have been redefined so as not to use
276        loops, in order to improve performance in some environments. At the same
277        time, I abstracted some of the common code into auxiliary macros to save
278        repetition (this should not affect the compiled code).
279    
280    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
281        compile-time error is now given if \c is not followed by an ASCII
282        character, that is, a byte less than 128. (In EBCDIC mode, the code is
283        different, and any byte value is allowed.)
284    
285    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
286        START_OPTIMIZE option, which is now allowed at compile time - but just
287        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
288        to pcregrep and other applications that have no direct access to PCRE
289        options. The new /Y option in pcretest sets this option when calling
290        pcre_compile().
291    
292    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
293        back references. Groups containing recursive back references were forced to
294        be atomic by that change, but in the case of named groups, the amount of
295        memory required was incorrectly computed, leading to "Failed: internal
296        error: code overflow". This has been fixed.
297    
298    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
299        pcretest.c, to avoid build problems in some Borland environments.
300    
301    
302    Version 8.10 25-Jun-2010
303    ------------------------
304    
305    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
306        THEN.
307    
308    2.  (*ACCEPT) was not working when inside an atomic group.
309    
310    3.  Inside a character class, \B is treated as a literal by default, but
311        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
312        causes the error). The code is unchanged, but I tidied the documentation.
313    
314    4.  Inside a character class, PCRE always treated \R and \X as literals,
315        whereas Perl faults them if its -w option is set. I have changed PCRE so
316        that it faults them when PCRE_EXTRA is set.
317    
318    5.  Added support for \N, which always matches any character other than
319        newline. (It is the same as "." when PCRE_DOTALL is not set.)
320    
321    6.  When compiling pcregrep with newer versions of gcc which may have
322        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
323        declared with attribute warn_unused_result" were given. Just casting the
324        result to (void) does not stop the warnings; a more elaborate fudge is
325        needed. I've used a macro to implement this.
326    
327    7.  Minor change to pcretest.c to avoid a compiler warning.
328    
329    8.  Added four artifical Unicode properties to help with an option to make
330        \s etc use properties (see next item). The new properties are: Xan
331        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
332    
333    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
334        use Unicode properties. (*UCP) at the start of a pattern can be used to set
335        this option. Modified pcretest to add /W to test this facility. Added
336        REG_UCP to make it available via the POSIX interface.
337    
338    10. Added --line-buffered to pcregrep.
339    
340    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
341        studied, and the match started with a letter with a code point greater than
342        127 whose first byte was different to the first byte of the other case of
343        the letter, the other case of this starting letter was not recognized
344        (#976).
345    
346    12. If a pattern that was studied started with a repeated Unicode property
347        test, for example, \p{Nd}+, there was the theoretical possibility of
348        setting up an incorrect bitmap of starting bytes, but fortunately it could
349        not have actually happened in practice until change 8 above was made (it
350        added property types that matched character-matching opcodes).
351    
352    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
353        possible starting bytes for non-anchored patterns.
354    
355    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
356        \R, and also a number of cases that involve Unicode properties, both
357        explicit and implicit when PCRE_UCP is set.
358    
359    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
360        input, it could crash or give wrong results if characters with values
361        greater than 0xc0 were present in the subject string. (Detail: it assumed
362        UTF-8 input when processing these items.)
363    
364    16. Added a lot of (int) casts to avoid compiler warnings in systems where
365        size_t is 64-bit (#991).
366    
367    17. Added a check for running out of memory when PCRE is compiled with
368        --disable-stack-for-recursion (#990).
369    
370    18. If the last data line in a file for pcretest does not have a newline on
371        the end, a newline was missing in the output.
372    
373    19. The default pcre_chartables.c file recognizes only ASCII characters (values
374        less than 128) in its various bitmaps. However, there is a facility for
375        generating tables according to the current locale when PCRE is compiled. It
376        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
377        characters, are recognized by isspace() and therefore were getting set in
378        these tables, and indeed these tables seem to approximate to ISO 8859. This
379        caused a problem in UTF-8 mode when pcre_study() was used to create a list
380        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
381        which of course cannot start UTF-8 characters. I have changed the code so
382        that only real ASCII characters (less than 128) and the correct starting
383        bytes for UTF-8 encodings are set for characters greater than 127 when in
384        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
385        altogether.)
386    
387    20. Added the /T option to pcretest so as to be able to run tests with non-
388        standard character tables, thus making it possible to include the tests
389        used for 19 above in the standard set of tests.
390    
391    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
392        reference to a subpattern the other side of a comment that contains an
393        opening parenthesis caused either an internal compiling error, or a
394        reference to the wrong subpattern.
395    
396    
397    Version 8.02 19-Mar-2010
398    ------------------------
399    
400    1.  The Unicode data tables have been updated to Unicode 5.2.0.
401    
402    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
403        configured.
404    
405    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
406        original author of that file, following a query about its status.
407    
408    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
409        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
410    
411    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
412        quantifier applied to a forward-referencing subroutine call, could compile
413        incorrect code or give the error "internal error: previously-checked
414        referenced subpattern not found".
415    
416    6.  Both MS Visual Studio and Symbian OS have problems with initializing
417        variables to point to external functions. For these systems, therefore,
418        pcre_malloc etc. are now initialized to local functions that call the
419        relevant global functions.
420    
421    7.  There were two entries missing in the vectors called coptable and poptable
422        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
423        I've fixed the data, and added a kludgy way of testing at compile time that
424        the lengths are correct (equal to the number of opcodes).
425    
426    8.  Following on from 7, I added a similar kludge to check the length of the
427        eint vector in pcreposix.c.
428    
429    9.  Error texts for pcre_compile() are held as one long string to avoid too
430        much relocation at load time. To find a text, the string is searched,
431        counting zeros. There was no check for running off the end of the string,
432        which could happen if a new error number was added without updating the
433        string.
434    
435    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
436    
437    11. \K was not working if it appeared in an atomic group or in a group that
438        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
439        \K is "not well defined" if used in an assertion. PCRE now accepts it if
440        the assertion is positive, but not if it is negative.
441    
442    12. Change 11 fortuitously reduced the size of the stack frame used in the
443        "match()" function of pcre_exec.c by one pointer. Forthcoming
444        implementation of support for (*MARK) will need an extra pointer on the
445        stack; I have reserved it now, so that the stack frame size does not
446        decrease.
447    
448    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
449        item in branch that calls a recursion is a subroutine call - as in the
450        second branch in the above example - was incorrectly given the compile-
451        time error "recursive call could loop indefinitely" because pcre_compile()
452        was not correctly checking the subroutine for matching a non-empty string.
453    
454    14. The checks for overrunning compiling workspace could trigger after an
455        overrun had occurred. This is a "should never occur" error, but it can be
456        triggered by pathological patterns such as hundreds of nested parentheses.
457        The checks now trigger 100 bytes before the end of the workspace.
458    
459    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
460    
461    
462    Version 8.01 19-Jan-2010
463    ------------------------
464    
465    1.  If a pattern contained a conditional subpattern with only one branch (in
466        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
467        computed the wrong minimum data length (which is of course zero for such
468        subpatterns). This could cause incorrect "no match" results.
469    
470    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
471        the pattern is reset in the first branch, pcre_compile() failed with
472        "internal error: code overflow at offset...". This happened only when
473        the reset was to the original external option setting. (An optimization
474        abstracts leading options settings into an external setting, which was the
475        cause of this.)
476    
477    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
478        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
479        assertion pattern did not match (meaning that the assertion was true), it
480        was incorrectly treated as false if the SKIP had been reached during the
481        matching. This also applied to assertions used as conditions.
482    
483    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
484        assertion subpattern, including such a pattern used as a condition,
485        unpredictable results occurred, instead of the error return
486        PCRE_ERROR_DFA_UITEM.
487    
488    5.  The C++ GlobalReplace function was not working like Perl for the special
489        situation when an empty string is matched. It now does the fancy magic
490        stuff that is necessary.
491    
492    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
493        removed. (These were left over from very, very early versions of PCRE.)
494    
495    7.  Some cosmetic changes to the code to make life easier when compiling it
496        as part of something else:
497    
498        (a) Change DEBUG to PCRE_DEBUG.
499    
500        (b) In pcre_compile(), rename the member of the "branch_chain" structure
501            called "current" as "current_branch", to prevent a collision with the
502            Linux macro when compiled as a kernel module.
503    
504        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
505            prevent a collision with the Linux macro when compiled as a kernel
506            module.
507    
508    8.  In pcre_compile() there are some checks for integer overflows that used to
509        cast potentially large values to (double). This has been changed to that
510        when building, a check for int64_t is made, and if it is found, it is used
511        instead, thus avoiding the use of floating point arithmetic. (There is no
512        other use of FP in PCRE.) If int64_t is not found, the fallback is to
513        double.
514    
515    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
516        2005 (difference between two addresses compared to an unsigned value).
517    
518    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
519        custom one, because of the following reported problem in Windows:
520    
521          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
522              under Win32.
523          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
524              therefore missing the function definition.
525          - The compiler thus generates a "C" signature for the test function.
526          - The linker fails to find the "C" function.
527          - PCRE fails to configure if asked to do so against libbz2.
528    
529    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
530        messages were output:
531    
532          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
533          rerunning libtoolize, to keep the correct libtool macros in-tree.
534          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
535    
536        I have done both of these things.
537    
538    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
539        most of the time, it *can* run out if it is given a pattern that contains a
540        runaway infinite recursion. I updated the discussion in the pcrestack man
541        page.
542    
543    13. Now that we have gone to the x.xx style of version numbers, the minor
544        version may start with zero. Using 08 or 09 is a bad idea because users
545        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
546        interpreted as invalid octal numbers. I've updated the previous comment in
547        configure.ac, and also added a check that gives an error if 08 or 09 are
548        used.
549    
550    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
551        causing partial matching to fail when the end of the subject matched \W
552        in a UTF-8 pattern where \W was quantified with a minimum of 3.
553    
554    15. There were some discrepancies between the declarations in pcre_internal.h
555        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
556        their definitions. The declarations used "const uschar *" and the
557        definitions used USPTR. Even though USPTR is normally defined as "const
558        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
559        reported that: "This difference in casting confuses some C++ compilers, for
560        example, SunCC recognizes above declarations as different functions and
561        generates broken code for hbpcre." I have changed the declarations to use
562        USPTR.
563    
564    16. GNU libtool is named differently on some systems. The autogen.sh script now
565        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
566        (FreeBSD).
567    
568    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
569        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
570        comment: "Figure out how to create a longlong from a string: strtoll and
571        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
572        instance, but it only takes 2 args instead of 3!"
573    
574    18. A subtle bug concerned with back references has been fixed by a change of
575        specification, with a corresponding code fix. A pattern such as
576        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
577        refers, was giving matches when it shouldn't. For example, xa=xaaa would
578        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
579        same bug. Such groups have to be quantified to be useful, or contained
580        inside another quantified group. (If there's no repetition, the reference
581        can never match.) The problem arises because, having left the group and
582        moved on to the rest of the pattern, a later failure that backtracks into
583        the group uses the captured value from the final iteration of the group
584        rather than the correct earlier one. I have fixed this in PCRE by forcing
585        any group that contains a reference to itself to be an atomic group; that
586        is, there cannot be any backtracking into it once it has completed. This is
587        similar to recursive and subroutine calls.
588    
589    
590    Version 8.00 19-Oct-09
591    ----------------------
592    
593    1.  The table for translating pcre_compile() error codes into POSIX error codes
594        was out-of-date, and there was no check on the pcre_compile() error code
595        being within the table. This could lead to an OK return being given in
596        error.
597    
598    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
599        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
600        in a Windows environment.
601    
602    3.  The pcregrep --count option prints the count for each file even when it is
603        zero, as does GNU grep. However, pcregrep was also printing all files when
604        --files-with-matches was added. Now, when both options are given, it prints
605        counts only for those files that have at least one match. (GNU grep just
606        prints the file name in this circumstance, but including the count seems
607        more useful - otherwise, why use --count?) Also ensured that the
608        combination -clh just lists non-zero counts, with no names.
609    
610    4.  The long form of the pcregrep -F option was incorrectly implemented as
611        --fixed_strings instead of --fixed-strings. This is an incompatible change,
612        but it seems right to fix it, and I didn't think it was worth preserving
613        the old behaviour.
614    
615    5.  The command line items --regex=pattern and --regexp=pattern were not
616        recognized by pcregrep, which required --regex pattern or --regexp pattern
617        (with a space rather than an '='). The man page documented the '=' forms,
618        which are compatible with GNU grep; these now work.
619    
620    6.  No libpcreposix.pc file was created for pkg-config; there was just
621        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
622    
623    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
624        when UCP support is not needed, by modifying the Python script that
625        generates it from Unicode data files. This should not matter if the module
626        is correctly used as a library, but I received one complaint about 50K of
627        unwanted data. My guess is that the person linked everything into his
628        program rather than using a library. Anyway, it does no harm.
629    
630    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
631        was a minimum greater than 1 for a wide character in a possessive
632        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
633        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
634        character. Chaos in the form of incorrect output or a compiling loop could
635        result.
636    
637    9.  The restrictions on what a pattern can contain when partial matching is
638        requested for pcre_exec() have been removed. All patterns can now be
639        partially matched by this function. In addition, if there are at least two
640        slots in the offset vector, the offset of the earliest inspected character
641        for the match and the offset of the end of the subject are set in them when
642        PCRE_ERROR_PARTIAL is returned.
643    
644    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
645        synonymous with PCRE_PARTIAL, for backwards compatibility, and
646        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
647        and may be more useful for multi-segment matching.
648    
649    11. Partial matching with pcre_exec() is now more intuitive. A partial match
650        used to be given if ever the end of the subject was reached; now it is
651        given only if matching could not proceed because another character was
652        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
653        string "Z", which now yields "no match" instead of "partial match". In the
654        case of pcre_dfa_exec(), "no match" is given if every matching path for the
655        final character ended with (*FAIL).
656    
657    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
658        if the pattern had a "must contain" character that was already found in the
659        earlier partial match, unless partial matching was again requested. For
660        example, with the pattern /dog.(body)?/, the "must contain" character is
661        "g". If the first part-match was for the string "dog", restarting with
662        "sbody" failed. This bug has been fixed.
663    
664    13. The string returned by pcre_dfa_exec() after a partial match has been
665        changed so that it starts at the first inspected character rather than the
666        first character of the match. This makes a difference only if the pattern
667        starts with a lookbehind assertion or \b or \B (\K is not supported by
668        pcre_dfa_exec()). It's an incompatible change, but it makes the two
669        matching functions compatible, and I think it's the right thing to do.
670    
671    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
672        so that the demonstration program is easily available in environments where
673        PCRE has not been installed from source.
674    
675    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
676        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
677        library.
678    
679    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
680        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
681        is not the first non-POSIX option to be added. Clearly some people find
682        these options useful.
683    
684    17. If a caller to the POSIX matching function regexec() passes a non-zero
685        value for nmatch with a NULL value for pmatch, the value of
686        nmatch is forced to zero.
687    
688    18. RunGrepTest did not have a test for the availability of the -u option of
689        the diff command, as RunTest does. It now checks in the same way as
690        RunTest, and also checks for the -b option.
691    
692    19. If an odd number of negated classes containing just a single character
693        interposed, within parentheses, between a forward reference to a named
694        subpattern and the definition of the subpattern, compilation crashed with
695        an internal error, complaining that it could not find the referenced
696        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
697        [The bug was that it was starting one character too far in when skipping
698        over the character class, thus treating the ] as data rather than
699        terminating the class. This meant it could skip too much.]
700    
701    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
702        /g option in pcretest when the pattern contains \K, which makes it possible
703        to have an empty string match not at the start, even when the pattern is
704        anchored. Updated pcretest and pcredemo to use this option.
705    
706    21. If the maximum number of capturing subpatterns in a recursion was greater
707        than the maximum at the outer level, the higher number was returned, but
708        with unset values at the outer level. The correct (outer level) value is
709        now given.
710    
711    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
712        PCRE did not set those parentheses (unlike Perl). I have now found a way to
713        make it do so. The string so far is captured, making this feature
714        compatible with Perl.
715    
716    23. The tests have been re-organized, adding tests 11 and 12, to make it
717        possible to check the Perl 5.10 features against Perl 5.10.
718    
719    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
720        pattern matches a fixed length string. PCRE did not allow this; now it
721        does. Neither allows recursion.
722    
723    25. I finally figured out how to implement a request to provide the minimum
724        length of subject string that was needed in order to match a given pattern.
725        (It was back references and recursion that I had previously got hung up
726        on.) This code has now been added to pcre_study(); it finds a lower bound
727        to the length of subject needed. It is not necessarily the greatest lower
728        bound, but using it to avoid searching strings that are too short does give
729        some useful speed-ups. The value is available to calling programs via
730        pcre_fullinfo().
731    
732    26. While implementing 25, I discovered to my embarrassment that pcretest had
733        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
734        study optimizations had never been tested with that matching function.
735        Oops. What is worse, even when it was passed study data, there was a bug in
736        pcre_dfa_exec() that meant it never actually used it. Double oops. There
737        were also very few tests of studied patterns with pcre_dfa_exec().
738    
739    27. If (?| is used to create subpatterns with duplicate numbers, they are now
740        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
741        on the other side of the coin, they are no longer allowed to have different
742        names, because these cannot be distinguished in PCRE, and this has caused
743        confusion. (This is a difference from Perl.)
744    
745    28. When duplicate subpattern names are present (necessarily with different
746        numbers, as required by 27 above), and a test is made by name in a
747        conditional pattern, either for a subpattern having been matched, or for
748        recursion in such a pattern, all the associated numbered subpatterns are
749        tested, and the overall condition is true if the condition is true for any
750        one of them. This is the way Perl works, and is also more like the way
751        testing by number works.
752    
753    
754    Version 7.9 11-Apr-09
755    ---------------------
756    
757    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
758        (pcretest), all targets were linked against these libraries. This included
759        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
760        libraries. This caused unwanted dependencies to be created. This problem
761        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
762        pcretest is linked with readline.
763    
764    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
765        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
766        moved outside it again, because FALSE and TRUE are already defined in AIX,
767        but BOOL is not.
768    
769    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
770        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
771    
772    4.  The pcregrep documentation said spaces were inserted as well as colons (or
773        hyphens) following file names and line numbers when outputting matching
774        lines. This is not true; no spaces are inserted. I have also clarified the
775        wording for the --colour (or --color) option.
776    
777    5.  In pcregrep, when --colour was used with -o, the list of matching strings
778        was not coloured; this is different to GNU grep, so I have changed it to be
779        the same.
780    
781    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
782        each matching line was coloured. Now it goes on to look for further matches
783        of any of the test patterns, which is the same behaviour as GNU grep.
784    
785    7.  A pattern that could match an empty string could cause pcregrep to loop; it
786        doesn't make sense to accept an empty string match in pcregrep, so I have
787        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
788        seems to be how GNU grep behaves.
789    
790    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
791        start or after a newline", because the conditional assertion was not being
792        correctly handled. The rule now is that both the assertion and what follows
793        in the first alternative must satisfy the test.
794    
795    9.  If auto-callout was enabled in a pattern with a conditional group whose
796        condition was an assertion, PCRE could crash during matching, both with
797        pcre_exec() and pcre_dfa_exec().
798    
799    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
800        used for matching.
801    
802    11. Unicode property support in character classes was not working for
803        characters (bytes) greater than 127 when not in UTF-8 mode.
804    
805    12. Added the -M command line option to pcretest.
806    
807    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
808    
809    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
810    
811    16. Added comments and documentation about mis-use of no_arg in the C++
812        wrapper.
813    
814    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
815        from Martin Jerabek that uses macro names for all relevant character and
816        string constants.
817    
818    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
819        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
820        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
821        these, but not everybody uses configure.
822    
823    19. A conditional group that had only one branch was not being correctly
824        recognized as an item that could match an empty string. This meant that an
825        enclosing group might also not be so recognized, causing infinite looping
826        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
827        with the subject "ab", where knowledge that the repeated group can match
828        nothing is needed in order to break the loop.
829    
830    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
831        exec(), but without supplying a callout function, matching went wrong.
832    
833    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
834        leak if the size of the offset vector was greater than 30. When the vector
835        is smaller, the saved offsets during recursion go onto a local stack
836        vector, but for larger vectors malloc() is used. It was failing to free
837        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
838        error, in fact).
839    
840    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
841        heapframe that is used only when UTF-8 support is enabled. This caused no
842        problem, but was untidy.
843    
844    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
845        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
846        included within another project.
847    
848    24. Steven Van Ingelgem's patches to add more options to the CMake support,
849        slightly modified by me:
850    
851          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
852              not building pcregrep.
853    
854          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
855              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
856    
857    25. Forward references, both numeric and by name, in patterns that made use of
858        duplicate group numbers, could behave incorrectly or give incorrect errors,
859        because when scanning forward to find the reference group, PCRE was not
860        taking into account the duplicate group numbers. A pattern such as
861        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
862    
863    26. Changed a few more instances of "const unsigned char *" to USPTR, making
864        the feature of a custom pointer more persuasive (as requested by a user).
865    
866    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
867        pcretest.c, inside #ifndefs, because it seems they are sometimes already
868        pre-defined.
869    
870    28. Added support for (*UTF8) at the start of a pattern.
871    
872    29. Arrange for flags added by the "release type" setting in CMake to be shown
873        in the configuration summary.
874    
875    
876    Version 7.8 05-Sep-08
877    ---------------------
878    
879    1.  Replaced UCP searching code with optimized version as implemented for Ad
880        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
881        stage table and inline lookup instead of a function, giving speed ups of 2
882        to 5 times on some simple patterns that I tested. Permission was given to
883        distribute the MultiStage2.py script that generates the tables (it's not in
884        the tarball, but is in the Subversion repository).
885    
886    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
887        scripts.
888    
889    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
890        a group with a zero qualifier. The result of the study could be incorrect,
891        or the function might crash, depending on the pattern.
892    
893    4.  Caseless matching was not working for non-ASCII characters in back
894        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
895        It now works when Unicode Property Support is available.
896    
897    5.  In pcretest, an escape such as \x{de} in the data was always generating
898        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
899        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
900        truncation.
901    
902    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
903    
904    7.  Added two (int) casts to pcregrep when printing the difference of two
905        pointers, in case they are 64-bit values.
906    
907    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
908        test 2 if it fails.
909    
910    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
911        and a #define of that name to empty if it is not externally set. This is to
912        allow users of MSVC to set it if necessary.
913    
914    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
915        the convenience functions in the pcre_get.c source file.
916    
917    11. An option change at the start of a pattern that had top-level alternatives
918        could cause overwriting and/or a crash. This command provoked a crash in
919        some environments:
920    
921          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
922    
923        This potential security problem was recorded as CVE-2008-2371.
924    
925    12. For a pattern where the match had to start at the beginning or immediately
926        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
927        pcre_dfa_exec() could read past the end of the passed subject if there was
928        no match. To help with detecting such bugs (e.g. with valgrind), I modified
929        pcretest so that it places the subject at the end of its malloc-ed buffer.
930    
931    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
932        exec() might read past the end of the data buffer in UTF-8 mode.
933    
934    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
935        the data contained the byte 0x85 as part of a UTF-8 character within its
936        first line. This applied both to normal and DFA matching.
937    
938    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
939        /^[^d]*?$/8 failed to match "abc".
940    
941    16. Added a missing copyright notice to pcrecpp_internal.h.
942    
943    17. Make it more clear in the documentation that values returned from
944        pcre_exec() in ovector are byte offsets, not character counts.
945    
946    18. Tidied a few places to stop certain compilers from issuing warnings.
947    
948    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
949        supplied by Stefan Weber. I made a further small update for 7.8 because
950        there is a change of source arrangements: the pcre_searchfuncs.c module is
951        replaced by pcre_ucd.c.
952    
953    
954    Version 7.7 07-May-08
955    ---------------------
956    
957    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
958        a string to a long long, pretend we don't even have a long long." This is
959        done by checking for the strtoq, strtoll, and _strtoi64 functions.
960    
961    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
962        pre-7.6 versions, which defined a global no_arg variable instead of putting
963        it in the RE class. (See also #8 below.)
964    
965    3.  Remove a line of dead code, identified by coverity and reported by Nuno
966        Lopes.
967    
968    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
969    
970        (1) The include/exclude patterns were being applied to the whole pathnames
971            of files, instead of just to the final components.
972    
973        (2) If there was more than one level of directory, the subdirectories were
974            skipped unless they satisfied the include/exclude conditions. This is
975            inconsistent with GNU grep (and could even be seen as contrary to the
976            pcregrep specification - which I improved to make it absolutely clear).
977            The action now is always to scan all levels of directory, and just
978            apply the include/exclude patterns to regular files.
979    
980    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
981        --exclude_dir in the tests to avoid scanning .svn directories.
982    
983    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
984        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
985        doesn't support NULs in patterns.
986    
987    7.  Added some missing "const"s to declarations of static tables in
988        pcre_compile.c and pcre_dfa_exec.c.
989    
990    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
991        caused by fix #2  above. (Subsequently also a second patch to fix the
992        first patch. And a third patch - this was a messy problem.)
993    
994    9.  Applied Craig's patch to remove the use of push_back().
995    
996    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
997        matching function regexec().
998    
999    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1000        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1001        references. PCRE supports relative numbers with this syntax (I don't think
1002        Oniguruma does).
1003    
1004    12. Previously, a group with a zero repeat such as (...){0} was completely
1005        omitted from the compiled regex. However, this means that if the group
1006        was called as a subroutine from elsewhere in the pattern, things went wrong
1007        (an internal error was given). Such groups are now left in the compiled
1008        pattern, with a new opcode that causes them to be skipped at execution
1009        time.
1010    
1011    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1012        to the way PCRE behaves:
1013    
1014        (a) A lone ] character is dis-allowed (Perl treats it as data).
1015    
1016        (b) A back reference to an unmatched subpattern matches an empty string
1017            (Perl fails the current match path).
1018    
1019        (c) A data ] in a character class must be notated as \] because if the
1020            first data character in a class is ], it defines an empty class. (In
1021            Perl it is not possible to have an empty class.) The empty class []
1022            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1023            The negative empty class [^] matches any one character, independently
1024            of the DOTALL setting.
1025    
1026    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1027        non-existent subpattern following a character class starting with ']' and
1028        containing () gave an internal compiling error instead of "reference to
1029        non-existent subpattern". Fortunately, when the pattern did exist, the
1030        compiled code was correct. (When scanning forwards to check for the
1031        existencd of the subpattern, it was treating the data ']' as terminating
1032        the class, so got the count wrong. When actually compiling, the reference
1033        was subsequently set up correctly.)
1034    
1035    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1036        it was being rejected as not supported by pcre_dfa_exec(), even though
1037        other assertions are supported. I have made pcre_dfa_exec() support
1038        (*FAIL).
1039    
1040    16. The implementation of 13c above involved the invention of a new opcode,
1041        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1042        cannot be changed at match time, I realized I could make a small
1043        improvement to matching performance by compiling OP_ALLANY instead of
1044        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1045        on the OP_ANY path.
1046    
1047    17. Compiling pcretest on Windows with readline support failed without the
1048        following two fixes: (1) Make the unistd.h include conditional on
1049        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1050    
1051    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1052        ncurses library to be included for pcretest when ReadLine support is
1053        requested, but also to allow for it to be overridden. This patch came from
1054        Daniel Bergström.
1055    
1056    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1057        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1058        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1059        spotting this.
1060    
1061    
1062    Version 7.6 28-Jan-08
1063    ---------------------
1064    
1065    1.  A character class containing a very large number of characters with
1066        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1067        overflow.
1068    
1069    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1070        HAVE_LONG_LONG is not defined.
1071    
1072    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1073        bring them up to date and include new features. This patch includes:
1074    
1075        - Fixed PH's badly added libz and libbz2 support.
1076        - Fixed a problem with static linking.
1077        - Added pcredemo. [But later removed - see 7 below.]
1078        - Fixed dftables problem and added an option.
1079        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1080            HAVE_LONG_LONG.
1081        - Added readline support for pcretest.
1082        - Added an listing of the option settings after cmake has run.
1083    
1084    4.  A user submitted a patch to Makefile that makes it easy to create
1085        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1086        Makefile.am that cause it to include this special target, without
1087        affecting anything else. Note that the same mingw target plus all
1088        the other distribution libraries and programs are now supported
1089        when configuring with CMake (see 6 below) instead of with
1090        Configure/Make.
1091    
1092    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1093        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1094        exported in the Windows port". It has not yet been confirmed that the patch
1095        solves the problem, but it does no harm.
1096    
1097    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1098        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1099        with CMake, and also correct the comment about stack recursion.
1100    
1101    7.  Remove the automatic building of pcredemo from the ./configure system and
1102        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1103        of a program that users should build themselves after PCRE is installed, so
1104        building it automatically is not really right. What is more, it gave
1105        trouble in some build environments.
1106    
1107    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1108    
1109    
1110    Version 7.5 10-Jan-08
1111  ---------------------  ---------------------
1112    
1113  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1114      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1115    
1116  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1117      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1118      included.      included.
1119    
1120  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
1121      [:^space:].      [:^space:].
1122    
1123  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1124      defined or documented. It seems to have been a typo for PCRE_STATIC, so      defined or documented. It seems to have been a typo for PCRE_STATIC, so
1125      I have changed it.      I have changed it.
1126    
1127  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1128      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
1129      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
1130      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
1131      expected" is now given for (?&) (a zero-length name), and this patch also      expected" is now given for (?&) (a zero-length name), and this patch also
1132      makes it give the same error for \k'' (previously it complained that that      makes it give the same error for \k'' (previously it complained that that
1133      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
1134    
1135  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1136      this is right because (?- can be followed by option settings as well as by      this is right because (?- can be followed by option settings as well as by
1137      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
1138    
1139  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1140      than the number used in the conditional) now cause a compile-time error.      than the number used in the conditional) now cause a compile-time error.
1141      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
1142      treats the conditional as always being FALSE (as PCRE used to), but it      treats the conditional as always being FALSE (as PCRE used to), but it
1143      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
1144    
1145  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
1146      and messages.      and messages.
1147    
1148  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
1149      "backspace".      "backspace".
1150    
1151  10. Remove two redundant lines of code that can never be obeyed (their function  10. Remove two redundant lines of code that can never be obeyed (their function
1152      was moved elsewhere).      was moved elsewhere).
1153    
1154  11. The program that makes PCRE's Unicode character property table had a bug  11. The program that makes PCRE's Unicode character property table had a bug
1155      which caused it to generate incorrect table entries for sequences of      which caused it to generate incorrect table entries for sequences of
1156      characters that have the same character type, but are in different scripts.      characters that have the same character type, but are in different scripts.
1157      It amalgamated them into a single range, with the script of the first of      It amalgamated them into a single range, with the script of the first of
1158      them. In other words, some characters were in the wrong script. There were      them. In other words, some characters were in the wrong script. There were
1159      thirteen such cases, affecting characters in the following ranges:      thirteen such cases, affecting characters in the following ranges:
1160    
1161        U+002b0 - U+002c1        U+002b0 - U+002c1
1162        U+0060c - U+0060d        U+0060c - U+0060d
1163        U+0061e - U+00612        U+0061e - U+00612
1164        U+0064b - U+0065e        U+0064b - U+0065e
1165        U+0074d - U+0076d        U+0074d - U+0076d
1166        U+01800 - U+01805        U+01800 - U+01805
# Line 65  Version 7.5 12-Nov-07 Line 1171  Version 7.5 12-Nov-07
1171        U+03260 - U+0327f        U+03260 - U+0327f
1172        U+0fb46 - U+0fbb1        U+0fb46 - U+0fbb1
1173        U+10450 - U+1049d        U+10450 - U+1049d
1174    
1175  12. The -o option (show only the matching part of a line) for pcregrep was not  12. The -o option (show only the matching part of a line) for pcregrep was not
1176      compatible with GNU grep in that, if there was more than one match in a      compatible with GNU grep in that, if there was more than one match in a
1177      line, it showed only the first of them. It now behaves in the same way as      line, it showed only the first of them. It now behaves in the same way as
1178      GNU grep.      GNU grep.
1179    
1180  13. If the -o and -v options were combined for pcregrep, it printed a blank  13. If the -o and -v options were combined for pcregrep, it printed a blank
1181      line for every non-matching line. GNU grep prints nothing, and pcregrep now      line for every non-matching line. GNU grep prints nothing, and pcregrep now
1182      does the same. The return code can be used to tell if there were any      does the same. The return code can be used to tell if there were any
1183      non-matching lines.      non-matching lines.
1184    
1185  14. The pattern (?=something)(?R) was not being diagnosed as a potentially  14. Added --file-offsets and --line-offsets to pcregrep.
1186    
1187    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1188      infinitely looping recursion. The bug was that positive lookaheads were not      infinitely looping recursion. The bug was that positive lookaheads were not
1189      being skipped when checking for a possible empty match (negative lookaheads      being skipped when checking for a possible empty match (negative lookaheads
1190      and both kinds of lookbehind were skipped).      and both kinds of lookbehind were skipped).
1191    
1192  15. Fixed two typos in the Windows-only code in pcregrep.c, and moved the  16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1193      inclusion of <windows.h> to before rather than after the definition of      inclusion of <windows.h> to before rather than after the definition of
1194      INVALID_FILE_ATTRIBUTES (patch from David Byron).      INVALID_FILE_ATTRIBUTES (patch from David Byron).
1195    
1196    17. Specifying a possessive quantifier with a specific limit for a Unicode
1197        character property caused pcre_compile() to compile bad code, which led at
1198        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1199        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1200        caused the error; without that there was no problem.
1201    
1202    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1203    
1204    19. Added --enable-pcretest-libreadline.
1205    
1206    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1207        RE::GlobalReplace(). As a result, the number of replacements returned was
1208        double what it should be. I removed one of the increments, but Craig sent a
1209        later patch that removed the other one (the right fix) and added unit tests
1210        that check the return values (which was not done before).
1211    
1212    21. Several CMake things:
1213    
1214        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1215            the names libpcre and libpcreposix, not just pcre and pcreposix.
1216    
1217        (2) The above change means that pcretest and pcregrep are now correctly
1218            linked with the newly-built libraries, not previously installed ones.
1219    
1220        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1221    
1222    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1223        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1224        UTF-8 newline character). The key issue is that the pattern starts .*;
1225        this means that the match must be either at the beginning, or after a
1226        newline. The bug was in the code for advancing after a failed match and
1227        checking that the new position followed a newline. It was not taking
1228        account of UTF-8 characters correctly.
1229    
1230    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1231        character classes. PCRE was not treating the sequence [:...:] as a
1232        character class unless the ... were all letters. Perl, however, seems to
1233        allow any characters between [: and :], though of course it rejects as
1234        unknown any "names" that contain non-letters, because all the known class
1235        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1236        for example, whereas PCRE did not - it did not recognize a POSIX character
1237        class. This seemed a bit dangerous, so the code has been changed to be
1238        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1239        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1240        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1241        Perl does, and where it didn't before.
1242    
1243    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1244        Windows environments %n is disabled by default.
1245    
1246    
1247  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07
1248  ---------------------  ---------------------

Legend:
Removed from v.284  
changed lines
  Added in v.618

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12