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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.31
5    -----------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12        to unsigned type, result still unsigned" that was given by an MS compiler
13        on encountering the code "-sizeof(xxx)".
14    
15    4.  Partial matching support is added to the JIT compiler.
16    
17    5.  Fixed several bugs concerned with partial matching of items that consist
18        of more than one character:
19    
20        (a) /^(..)\1/ did not partially match "aba" because checking references was
21            done on an "all or nothing" basis. This also applied to repeated
22            references.
23    
24        (b) \R did not give a hard partial match if \r was found at the end of the
25            subject.
26    
27        (c) \X did not give a hard partial match after matching one or more
28            characters at the end of the subject.
29    
30        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31            a partial match for the string "\r".
32    
33        (e) When newline was set to CRLF, the metacharacter "." did not recognize
34            a partial match for a CR character at the end of the subject string.
35    
36    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
37        running pcretest, the text "(JIT)" added to the output whenever JIT is
38        actually used to run the match.
39    
40    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
41        or /S+[+] with a digit between 1 and 7.
42    
43    8.  OP_NOT now supports any UTF character not just single-byte ones.
44    
45    9.  (*MARK) control verb is now supported by the JIT compiler.
46    
47    10. The command "./RunTest list" lists the available tests without actually
48        running any of them. (Because I keep forgetting what they all are.)
49    
50    11. Add PCRE_INFO_MAXLOOKBEHIND.
51    
52    12. Applied a (slightly modified) user-supplied patch that improves performance
53        when the heap is used for recursion (compiled with --disable-stack-for-
54        recursion). Instead of malloc and free for each heap frame each time a
55        logical recursion happens, frames are retained on a chain and re-used where
56        possible. This sometimes gives as much as 30% improvement.
57    
58    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
59        call.
60    
61    14. As documented, (*COMMIT) is now confined to within a positive assertion.
62    
63    15. It is now possible to link pcretest with libedit as an alternative to
64        libreadline.
65    
66    16. (*COMMIT) control verb is now supported by the JIT compiler.
67    
68    
69    Version 8.30 04-February-2012
70    -----------------------------
71    
72    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
73        name is defined in ctype.h.
74    
75    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
76        only in quite long subpatterns.
77    
78    3.  Removed the function pcre_info(), which has been obsolete and deprecated
79        since it was replaced by pcre_fullinfo() in February 2000.
80    
81    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
82        match a (*MARK), and the match failed at the start of the subject, a
83        reference to memory before the start of the subject could occur. This bug
84        was introduced by fix 17 of release 8.21.
85    
86    5.  A reference to an unset group with zero minimum repetition was giving
87        totally wrong answers (in non-JavaScript-compatibility mode). For example,
88        /(another)?(\1?)test/ matched against "hello world test". This bug was
89        introduced in release 8.13.
90    
91    6.  Add support for 16-bit character strings (a large amount of work involving
92        many changes and refactorings).
93    
94    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
95        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
96        from a file.
97    
98    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
99        rounding is not applied in this particular case).
100    
101    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
102        if they appear, or are escaped, in patterns.
103    
104    10. Get rid of a number of -Wunused-but-set-variable warnings.
105    
106    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
107        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
108        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
109        also returns the mark "x". This bug applied to capturing parentheses,
110        non-capturing parentheses, and atomic parentheses. It also applied to some
111        assertions.
112    
113    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
114        information out of configure.ac instead of relying on pcre.h.generic, which
115        is not stored in the repository.
116    
117    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
118        -lreadline.
119    
120    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
121    
122    15. Applied Graycode's patch to put the top-level frame on the stack rather
123        than the heap when not using the stack for recursion. This gives a
124        performance improvement in many cases when recursion is not deep.
125    
126    16. Experimental code added to "pcretest -C" to output the stack frame size.
127    
128    
129    Version 8.21 12-Dec-2011
130    ------------------------
131    
132    1.  Updating the JIT compiler.
133    
134    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
135        are added as well.
136    
137    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
138        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
139        calling _pcre_jit_exec. Some extra comments are added.
140    
141    4.  (*MARK) settings inside atomic groups that do not contain any capturing
142        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
143        was introduced by change 18 for 8.20.
144    
145    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
146        ECMA-262 standard.
147    
148    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
149        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
150        This bug was probably introduced by change 9 of 8.13.
151    
152    7.  While fixing 6 above, I noticed that a number of other items were being
153        incorrectly rejected as "not fixed length". This arose partly because newer
154        opcodes had not been added to the fixed-length checking code. I have (a)
155        corrected the bug and added tests for these items, and (b) arranged for an
156        error to occur if an unknown opcode is encountered while checking for fixed
157        length instead of just assuming "not fixed length". The items that were
158        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
159        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
160        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
161    
162    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
163        being incorrectly compiled and would have given unpredicatble results.
164    
165    9.  A possessively repeated subpattern with minimum repeat count greater than
166        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
167        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
168        the first (A) could occur when it should not.
169    
170    10. Add a cast and remove a redundant test from the code.
171    
172    11. JIT should use pcre_malloc/pcre_free for allocation.
173    
174    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
175        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
176        is anything other than /usr, -L is still shown).
177    
178    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
179    
180    14. Perl does not support \N without a following name in a [] class; PCRE now
181        also gives an error.
182    
183    15. If a forward reference was repeated with an upper limit of around 2000,
184        it caused the error "internal error: overran compiling workspace". The
185        maximum number of forward references (including repeats) was limited by the
186        internal workspace, and dependent on the LINK_SIZE. The code has been
187        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
188        the default depends on LINK_SIZE. There is a new upper limit (for safety)
189        of around 200,000 forward references. While doing this, I also speeded up
190        the filling in of repeated forward references.
191    
192    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
193        incorrectly expecting the subject to contain another "a" after the start.
194    
195    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
196        in the match, the SKIP should be ignored. This was not happening; instead
197        the SKIP was being treated as NOMATCH. For patterns such as
198        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
199        tested.
200    
201    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
202        now much more compatible with Perl, in particular in cases where the result
203        is a non-match for a non-anchored pattern. For example, if
204        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
205        "m", where previously it did not return a name. A side effect of this
206        change is that for partial matches, the last encountered mark name is
207        returned, as for non matches. A number of tests that were previously not
208        Perl-compatible have been moved into the Perl-compatible test files. The
209        refactoring has had the pleasing side effect of removing one argument from
210        the match() function, thus reducing its stack requirements.
211    
212    19. If the /S+ option was used in pcretest to study a pattern using JIT,
213        subsequent uses of /S (without +) incorrectly behaved like /S+.
214    
215    21. Retrieve executable code size support for the JIT compiler and fixing
216        some warnings.
217    
218    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
219        not work when the shorter character appeared right at the end of the
220        subject string.
221    
222    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
223        systems.
224    
225    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
226        output it when the /M option is used in pcretest.
227    
228    25. The CheckMan script was not being included in the distribution. Also, added
229        an explicit "perl" to run Perl scripts from the PrepareRelease script
230        because this is reportedly needed in Windows.
231    
232    26. If study data was being save in a file and studying had not found a set of
233        "starts with" bytes for the pattern, the data written to the file (though
234        never used) was taken from uninitialized memory and so caused valgrind to
235        complain.
236    
237    27. Updated RunTest.bat as provided by Sheri Pierce.
238    
239    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
240    
241    29. Computation of memory usage for the table of capturing group names was
242        giving an unnecessarily large value.
243    
244    
245    Version 8.20 21-Oct-2011
246    ------------------------
247    
248    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
249        a POSIX class. After further experiments with Perl, which convinced me that
250        Perl has bugs and confusions, a closing square bracket is no longer allowed
251        in a POSIX name. This bug also affected patterns with classes that started
252        with full stops.
253    
254    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
255        captured substring, but while checking the failing first alternative,
256        substring 1 is temporarily captured. If the output vector supplied to
257        pcre_exec() was not big enough for this capture, the yield of the function
258        was still zero ("insufficient space for captured substrings"). This cannot
259        be totally fixed without adding another stack variable, which seems a lot
260        of expense for a edge case. However, I have improved the situation in cases
261        such as /(a)(b)x|abc/ matched against "abc", where the return code
262        indicates that fewer than the maximum number of slots in the ovector have
263        been set.
264    
265    3.  Related to (2) above: when there are more back references in a pattern than
266        slots in the output vector, pcre_exec() uses temporary memory during
267        matching, and copies in the captures as far as possible afterwards. It was
268        using the entire output vector, but this conflicts with the specification
269        that only 2/3 is used for passing back captured substrings. Now it uses
270        only the first 2/3, for compatibility. This is, of course, another edge
271        case.
272    
273    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
274        main code base, and can be used by building with --enable-jit. When this is
275        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
276        runtime --no-jit option is given.
277    
278    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
279        ovector, the return from the function was zero, implying that there were
280        other matches that did not fit. The correct "exactly full" value is now
281        returned.
282    
283    6.  If a subpattern that was called recursively or as a subroutine contained
284        (*PRUNE) or any other control that caused it to give a non-standard return,
285        invalid errors such as "Error -26 (nested recursion at the same subject
286        position)" or even infinite loops could occur.
287    
288    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
289        computing the minimum length on reaching *ACCEPT, and so ended up with the
290        wrong value of 1 rather than 0. Further investigation indicates that
291        computing a minimum subject length in the presence of *ACCEPT is difficult
292        (think back references, subroutine calls), and so I have changed the code
293        so that no minimum is registered for a pattern that contains *ACCEPT.
294    
295    8.  If (*THEN) was present in the first (true) branch of a conditional group,
296        it was not handled as intended. [But see 16 below.]
297    
298    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
299        Sheri Pierce.
300    
301    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
302        the first byte in a match must be "a".
303    
304    11. Change 17 for 8.13 increased the recursion depth for patterns like
305        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
306        pattern contains any instances of (*THEN). If it does not, the old
307        optimizations are restored. It would be nice to do this on a per-group
308        basis, but at the moment that is not feasible.
309    
310    12. In some environments, the output of pcretest -C is CRLF terminated. This
311        broke RunTest's code that checks for the link size. A single white space
312        character after the value is now allowed for.
313    
314    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
315        For "fr", it uses the Windows-specific input and output files.
316    
317    14. If (*THEN) appeared in a group that was called recursively or as a
318        subroutine, it did not work as intended. [But see next item.]
319    
320    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
321        pattern fragments (but not containing any | characters). If A and B are
322        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
323        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
324        D. In other words, Perl considers parentheses that do not contain any |
325        characters to be part of a surrounding alternative, whereas PCRE was
326        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
327        differently. PCRE now behaves in the same way as Perl, except in the case
328        of subroutine/recursion calls such as (?1) which have in any case always
329        been different (but PCRE had them first :-).
330    
331    16. Related to 15 above: Perl does not treat the | in a conditional group as
332        creating alternatives. Such a group is treated in the same way as an
333        ordinary group without any | characters when processing (*THEN). PCRE has
334        been changed to match Perl's behaviour.
335    
336    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
337        RunGrepTest script failed.
338    
339    18. Change 22 for version 13 caused atomic groups to use more stack. This is
340        inevitable for groups that contain captures, but it can lead to a lot of
341        stack use in large patterns. The old behaviour has been restored for atomic
342        groups that do not contain any capturing parentheses.
343    
344    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
345        suppress the check for a minimum subject length at run time. (If it was
346        given to pcre_exec() or pcre_dfa_exec() it did work.)
347    
348    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
349        fail to work when decoding hex characters in data strings in EBCDIC
350        environments.
351    
352    21. It appears that in at least one Mac OS environment, the isxdigit() function
353        is implemented as a macro that evaluates to its argument more than once,
354        contravening the C 90 Standard (I haven't checked a later standard). There
355        was an instance in pcretest which caused it to go wrong when processing
356        \x{...} escapes in subject strings. The has been rewritten to avoid using
357        things like p++ in the argument of isxdigit().
358    
359    
360    Version 8.13 16-Aug-2011
361    ------------------------
362    
363    1.  The Unicode data tables have been updated to Unicode 6.0.0.
364    
365    2.  Two minor typos in pcre_internal.h have been fixed.
366    
367    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
368        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
369        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
370    
371    4.  There were a number of related bugs in the code for matching backrefences
372        caselessly in UTF-8 mode when codes for the characters concerned were
373        different numbers of bytes. For example, U+023A and U+2C65 are an upper
374        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
375        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
376        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
377        2-byte code at the end of the subject (it thought there wasn't enough data
378        left).
379    
380    5.  Comprehensive information about what went wrong is now returned by
381        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
382        as the output vector has at least 2 elements. The offset of the start of
383        the failing character and a reason code are placed in the vector.
384    
385    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
386        now returned is for the first byte of the failing character, instead of the
387        last byte inspected. This is an incompatible change, but I hope it is small
388        enough not to be a problem. It makes the returned offset consistent with
389        pcre_exec() and pcre_dfa_exec().
390    
391    7.  pcretest now gives a text phrase as well as the error number when
392        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
393        failure, the offset and reason code are output.
394    
395    8.  When \R was used with a maximizing quantifier it failed to skip backwards
396        over a \r\n pair if the subsequent match failed. Instead, it just skipped
397        back over a single character (\n). This seems wrong (because it treated the
398        two characters as a single entity when going forwards), conflicts with the
399        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
400        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
401        has been changed.
402    
403    9.  Some internal refactoring has changed the processing so that the handling
404        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
405        time (the PCRE_DOTALL option was changed this way some time ago: version
406        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
407        which was always a bit of a fudge. It also means that there is one less
408        argument for the match() function, which reduces its stack requirements
409        slightly. This change also fixes an incompatibility with Perl: the pattern
410        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
411    
412    10. More internal refactoring has drastically reduced the number of recursive
413        calls to match() for possessively repeated groups such as (abc)++ when
414        using pcre_exec().
415    
416    11. While implementing 10, a number of bugs in the handling of groups were
417        discovered and fixed:
418    
419        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
420        (a|)*(?1) gave a compile-time internal error.
421        ((a|)+)+  did not notice that the outer group could match an empty string.
422        (^a|^)+   was not marked as anchored.
423        (.*a|.*)+ was not marked as matching at start or after a newline.
424    
425    12. Yet more internal refactoring has removed another argument from the match()
426        function. Special calls to this function are now indicated by setting a
427        value in a variable in the "match data" data block.
428    
429    13. Be more explicit in pcre_study() instead of relying on "default" for
430        opcodes that mean there is no starting character; this means that when new
431        ones are added and accidentally left out of pcre_study(), testing should
432        pick them up.
433    
434    14. The -s option of pcretest has been documented for ages as being an old
435        synonym of -m (show memory usage). I have changed it to mean "force study
436        for every regex", that is, assume /S for every regex. This is similar to -i
437        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
438        using it. It makes it easier to run collections of tests with and without
439        study enabled, and thereby test pcre_study() more easily. All the standard
440        tests are now run with and without -s (but some patterns can be marked as
441        "never study" - see 20 below).
442    
443    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
444        restoration of the capturing data to the outer values was not happening
445        correctly.
446    
447    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
448        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
449        pattern had matched an empty string, and so incorrectly returned a no
450        match.
451    
452    17. There was optimizing code for the last branch of non-capturing parentheses,
453        and also for the obeyed branch of a conditional subexpression, which used
454        tail recursion to cut down on stack usage. Unfortunately, now that there is
455        the possibility of (*THEN) occurring in these branches, tail recursion is
456        no longer possible because the return has to be checked for (*THEN). These
457        two optimizations have therefore been removed. [But see 8.20/11 above.]
458    
459    18. If a pattern containing \R was studied, it was assumed that \R always
460        matched two bytes, thus causing the minimum subject length to be
461        incorrectly computed because \R can also match just one byte.
462    
463    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
464        was incorrectly computed.
465    
466    20. If /S is present twice on a test pattern in pcretest input, it now
467        *disables* studying, thereby overriding the use of -s on the command line
468        (see 14 above). This is necessary for one or two tests to keep the output
469        identical in both cases.
470    
471    21. When (*ACCEPT) was used in an assertion that matched an empty string and
472        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
473    
474    22. When an atomic group that contained a capturing parenthesis was
475        successfully matched, but the branch in which it appeared failed, the
476        capturing was not being forgotten if a higher numbered group was later
477        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
478        group 1 to "a", when in fact it should be unset. This applied to multi-
479        branched capturing and non-capturing groups, repeated or not, and also to
480        positive assertions (capturing in negative assertions does not happen
481        in PCRE) and also to nested atomic groups.
482    
483    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
484        subject after a captured substring, to make it easier to tell which of a
485        number of identical substrings has been captured.
486    
487    24. The way atomic groups are processed by pcre_exec() has been changed so that
488        if they are repeated, backtracking one repetition now resets captured
489        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
490        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
491        "aaa". Previously, it would have been "a". As part of this code
492        refactoring, the way recursive calls are handled has also been changed.
493    
494    25. If an assertion condition captured any substrings, they were not passed
495        back unless some other capturing happened later. For example, if
496        (?(?=(a))a) was matched against "a", no capturing was returned.
497    
498    26. When studying a pattern that contained subroutine calls or assertions,
499        the code for finding the minimum length of a possible match was handling
500        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
501        group 1 called group 2 while simultaneously a separate group 2 called group
502        1). A stack overflow occurred in this case. I have fixed this by limiting
503        the recursion depth to 10.
504    
505    27. Updated RunTest.bat in the distribution to the version supplied by Tom
506        Fortmann. This supports explicit test numbers on the command line, and has
507        argument validation and error reporting.
508    
509    28. An instance of \X with an unlimited repeat could fail if at any point the
510        first character it looked at was a mark character.
511    
512    29. Some minor code refactoring concerning Unicode properties and scripts
513        should reduce the stack requirement of match() slightly.
514    
515    30. Added the '=' option to pcretest to check the setting of unused capturing
516        slots at the end of the pattern, which are documented as being -1, but are
517        not included in the return count.
518    
519    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
520        compiled something random. Now it gives a compile-time error (as does
521        Perl).
522    
523    32. A *MARK encountered during the processing of a positive assertion is now
524        recorded and passed back (compatible with Perl).
525    
526    33. If --only-matching or --colour was set on a pcregrep call whose pattern
527        had alternative anchored branches, the search for a second match in a line
528        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
529        matched the line "0102" twice. The same bug affected patterns that started
530        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
531        twice.
532    
533    34. Previously, PCRE did not allow quantification of assertions. However, Perl
534        does, and because of capturing effects, quantifying parenthesized
535        assertions may at times be useful. Quantifiers are now allowed for
536        parenthesized assertions.
537    
538    35. A minor code tidy in pcre_compile() when checking options for \R usage.
539    
540    36. \g was being checked for fancy things in a character class, when it should
541        just be a literal "g".
542    
543    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
544        appearance of a nested POSIX class supersedes an apparent external class.
545        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
546        unescaped square brackets may also appear as part of class names. For
547        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
548        more like Perl. (But see 8.20/1 above.)
549    
550    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
551        was because it thought it was \N{name}, which is not supported).
552    
553    39. Add minix to OS list not supporting the -S option in pcretest.
554    
555    40. PCRE tries to detect cases of infinite recursion at compile time, but it
556        cannot analyze patterns in sufficient detail to catch mutual recursions
557        such as ((?1))((?2)). There is now a runtime test that gives an error if a
558        subgroup is called recursively as a subpattern for a second time at the
559        same position in the subject string. In previous releases this might have
560        been caught by the recursion limit, or it might have run out of stack.
561    
562    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
563        happen only once. PCRE was, however incorrectly giving a compile time error
564        "recursive call could loop indefinitely" because it cannot analyze the
565        pattern in sufficient detail. The compile time test no longer happens when
566        PCRE is compiling a conditional subpattern, but actual runaway loops are
567        now caught at runtime (see 40 above).
568    
569    42. It seems that Perl allows any characters other than a closing parenthesis
570        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
571        has been changed to be the same.
572    
573    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
574        as not to get warnings when autogen.sh is called. Also changed
575        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
576    
577    44. To help people who use pcregrep to scan files containing exceedingly long
578        lines, the following changes have been made:
579    
580        (a) The default value of the buffer size parameter has been increased from
581            8K to 20K. (The actual buffer used is three times this size.)
582    
583        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
584            PCRE is built.
585    
586        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
587            to be set at run time.
588    
589        (d) Numerical values in pcregrep options can be followed by K or M, for
590            example --buffer-size=50K.
591    
592        (e) If a line being scanned overflows pcregrep's buffer, an error is now
593            given and the return code is set to 2.
594    
595    45. Add a pointer to the latest mark to the callout data block.
596    
597    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
598        partial match of an empty string instead of no match. This was specific to
599        the use of ".".
600    
601    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
602        complete match instead of a partial match. This bug was dependent on both
603        the PCRE_UTF8 and PCRE_DOTALL options being set.
604    
605    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
606        starting byte set, because \b was not being ignored.
607    
608    
609    Version 8.12 15-Jan-2011
610    ------------------------
611    
612    1.  Fixed some typos in the markup of the man pages, and wrote a script that
613        checks for such things as part of the documentation building process.
614    
615    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
616        --match-limit and --recursion-limit options (added for 8.11). In
617        particular, this made one of the standard tests fail. (The integer value
618        went into the wrong half of a long int.)
619    
620    3.  If the --colour option was given to pcregrep with -v (invert match), it
621        did strange things, either producing crazy output, or crashing. It should,
622        of course, ignore a request for colour when reporting lines that do not
623        match.
624    
625    4.  Another pcregrep bug caused similar problems if --colour was specified with
626        -M (multiline) and the pattern match finished with a line ending.
627    
628    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
629        matched in multiline mode, the following line was shown as part of the
630        match. This seems wrong, so I have changed it.
631    
632    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
633        the check for further matches in the same line (so they could be coloured)
634        to overrun the end of the current line. If another match was found, it was
635        incorrectly shown (and then shown again when found in the next line).
636    
637    7.  If pcregrep was compiled under Windows, there was a reference to the
638        function pcregrep_exit() before it was defined. I am assuming this was
639        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
640        reported by a user. I've moved the definition above the reference.
641    
642    
643    Version 8.11 10-Dec-2010
644    ------------------------
645    
646    1.  (*THEN) was not working properly if there were untried alternatives prior
647        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
648        backtracked to try for "b" instead of moving to the next alternative branch
649        at the same level (in this case, to look for "c"). The Perl documentation
650        is clear that when (*THEN) is backtracked onto, it goes to the "next
651        alternative in the innermost enclosing group".
652    
653    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
654        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
655        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
656        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
657        (*THEN).
658    
659    3.  If \s appeared in a character class, it removed the VT character from
660        the class, even if it had been included by some previous item, for example
661        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
662        of \s, but is part of the POSIX "space" class.)
663    
664    4.  A partial match never returns an empty string (because you can always
665        match an empty string at the end of the subject); however the checking for
666        an empty string was starting at the "start of match" point. This has been
667        changed to the "earliest inspected character" point, because the returned
668        data for a partial match starts at this character. This means that, for
669        example, /(?<=abc)def/ gives a partial match for the subject "abc"
670        (previously it gave "no match").
671    
672    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
673        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
674        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
675        has an implication that the given string is incomplete (because a partial
676        match is preferred over a full match). For this reason, these items now
677        give a partial match in this situation. [Aside: previously, the one case
678        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
679        match rather than a full match, which was wrong by the old rules, but is
680        now correct.]
681    
682    6.  There was a bug in the handling of #-introduced comments, recognized when
683        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
684        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
685        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
686        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
687        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
688        places in pcre_compile().
689    
690    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
691        comments when looking ahead for named forward references to subpatterns,
692        the only newline sequence it recognized was NL. It now handles newlines
693        according to the set newline convention.
694    
695    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
696        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
697        cater for a lack of strerror(). These oversights have been fixed.
698    
699    9.  Added --match-limit and --recursion-limit to pcregrep.
700    
701    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
702    
703    11. When the -o option was used, pcregrep was setting a return code of 1, even
704        when matches were found, and --line-buffered was not being honoured.
705    
706    12. Added an optional parentheses number to the -o and --only-matching options
707        of pcregrep.
708    
709    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
710        can match an empty string. The code to do it in pcretest and pcredemo
711        needed fixing:
712    
713        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
714            only one byte after an empty string match just before CRLF (this case
715            just got forgotten; "any" and "anycrlf" were OK).
716    
717        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
718            mode when an empty string match preceded an ASCII character followed by
719            a non-ASCII character. (The code for advancing by one character rather
720            than one byte was nonsense.)
721    
722        (c) The pcredemo.c sample program did not have any code at all to handle
723            the cases when CRLF is a valid newline sequence.
724    
725    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
726        as a starting offset was within the subject string. There is now a new
727        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
728        negative or greater than the length of the string. In order to test this,
729        pcretest is extended to allow the setting of negative starting offsets.
730    
731    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
732        starting offset points to the beginning of a UTF-8 character was
733        unnecessarily clumsy. I tidied it up.
734    
735    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
736        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
737    
738    17. Nobody had reported that the --include_dir option, which was added in
739        release 7.7 should have been called --include-dir (hyphen, not underscore)
740        for compatibility with GNU grep. I have changed it to --include-dir, but
741        left --include_dir as an undocumented synonym, and the same for
742        --exclude-dir, though that is not available in GNU grep, at least as of
743        release 2.5.4.
744    
745    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
746        characters from a string of bytes) have been redefined so as not to use
747        loops, in order to improve performance in some environments. At the same
748        time, I abstracted some of the common code into auxiliary macros to save
749        repetition (this should not affect the compiled code).
750    
751    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
752        compile-time error is now given if \c is not followed by an ASCII
753        character, that is, a byte less than 128. (In EBCDIC mode, the code is
754        different, and any byte value is allowed.)
755    
756    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
757        START_OPTIMIZE option, which is now allowed at compile time - but just
758        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
759        to pcregrep and other applications that have no direct access to PCRE
760        options. The new /Y option in pcretest sets this option when calling
761        pcre_compile().
762    
763    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
764        back references. Groups containing recursive back references were forced to
765        be atomic by that change, but in the case of named groups, the amount of
766        memory required was incorrectly computed, leading to "Failed: internal
767        error: code overflow". This has been fixed.
768    
769    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
770        pcretest.c, to avoid build problems in some Borland environments.
771    
772    
773    Version 8.10 25-Jun-2010
774    ------------------------
775    
776    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
777        THEN.
778    
779    2.  (*ACCEPT) was not working when inside an atomic group.
780    
781    3.  Inside a character class, \B is treated as a literal by default, but
782        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
783        causes the error). The code is unchanged, but I tidied the documentation.
784    
785    4.  Inside a character class, PCRE always treated \R and \X as literals,
786        whereas Perl faults them if its -w option is set. I have changed PCRE so
787        that it faults them when PCRE_EXTRA is set.
788    
789    5.  Added support for \N, which always matches any character other than
790        newline. (It is the same as "." when PCRE_DOTALL is not set.)
791    
792    6.  When compiling pcregrep with newer versions of gcc which may have
793        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
794        declared with attribute warn_unused_result" were given. Just casting the
795        result to (void) does not stop the warnings; a more elaborate fudge is
796        needed. I've used a macro to implement this.
797    
798    7.  Minor change to pcretest.c to avoid a compiler warning.
799    
800    8.  Added four artifical Unicode properties to help with an option to make
801        \s etc use properties (see next item). The new properties are: Xan
802        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
803    
804    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
805        use Unicode properties. (*UCP) at the start of a pattern can be used to set
806        this option. Modified pcretest to add /W to test this facility. Added
807        REG_UCP to make it available via the POSIX interface.
808    
809    10. Added --line-buffered to pcregrep.
810    
811    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
812        studied, and the match started with a letter with a code point greater than
813        127 whose first byte was different to the first byte of the other case of
814        the letter, the other case of this starting letter was not recognized
815        (#976).
816    
817    12. If a pattern that was studied started with a repeated Unicode property
818        test, for example, \p{Nd}+, there was the theoretical possibility of
819        setting up an incorrect bitmap of starting bytes, but fortunately it could
820        not have actually happened in practice until change 8 above was made (it
821        added property types that matched character-matching opcodes).
822    
823    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
824        possible starting bytes for non-anchored patterns.
825    
826    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
827        \R, and also a number of cases that involve Unicode properties, both
828        explicit and implicit when PCRE_UCP is set.
829    
830    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
831        input, it could crash or give wrong results if characters with values
832        greater than 0xc0 were present in the subject string. (Detail: it assumed
833        UTF-8 input when processing these items.)
834    
835    16. Added a lot of (int) casts to avoid compiler warnings in systems where
836        size_t is 64-bit (#991).
837    
838    17. Added a check for running out of memory when PCRE is compiled with
839        --disable-stack-for-recursion (#990).
840    
841    18. If the last data line in a file for pcretest does not have a newline on
842        the end, a newline was missing in the output.
843    
844    19. The default pcre_chartables.c file recognizes only ASCII characters (values
845        less than 128) in its various bitmaps. However, there is a facility for
846        generating tables according to the current locale when PCRE is compiled. It
847        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
848        characters, are recognized by isspace() and therefore were getting set in
849        these tables, and indeed these tables seem to approximate to ISO 8859. This
850        caused a problem in UTF-8 mode when pcre_study() was used to create a list
851        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
852        which of course cannot start UTF-8 characters. I have changed the code so
853        that only real ASCII characters (less than 128) and the correct starting
854        bytes for UTF-8 encodings are set for characters greater than 127 when in
855        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
856        altogether.)
857    
858    20. Added the /T option to pcretest so as to be able to run tests with non-
859        standard character tables, thus making it possible to include the tests
860        used for 19 above in the standard set of tests.
861    
862    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
863        reference to a subpattern the other side of a comment that contains an
864        opening parenthesis caused either an internal compiling error, or a
865        reference to the wrong subpattern.
866    
867    
868    Version 8.02 19-Mar-2010
869  ------------------------  ------------------------
870    
871  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
872    
873    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
874        configured.
875    
876    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
877        original author of that file, following a query about its status.
878    
879    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
880        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
881    
882    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
883        quantifier applied to a forward-referencing subroutine call, could compile
884        incorrect code or give the error "internal error: previously-checked
885        referenced subpattern not found".
886    
887    6.  Both MS Visual Studio and Symbian OS have problems with initializing
888        variables to point to external functions. For these systems, therefore,
889        pcre_malloc etc. are now initialized to local functions that call the
890        relevant global functions.
891    
892    7.  There were two entries missing in the vectors called coptable and poptable
893        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
894        I've fixed the data, and added a kludgy way of testing at compile time that
895        the lengths are correct (equal to the number of opcodes).
896    
897    8.  Following on from 7, I added a similar kludge to check the length of the
898        eint vector in pcreposix.c.
899    
900    9.  Error texts for pcre_compile() are held as one long string to avoid too
901        much relocation at load time. To find a text, the string is searched,
902        counting zeros. There was no check for running off the end of the string,
903        which could happen if a new error number was added without updating the
904        string.
905    
906    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
907    
908    11. \K was not working if it appeared in an atomic group or in a group that
909        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
910        \K is "not well defined" if used in an assertion. PCRE now accepts it if
911        the assertion is positive, but not if it is negative.
912    
913    12. Change 11 fortuitously reduced the size of the stack frame used in the
914        "match()" function of pcre_exec.c by one pointer. Forthcoming
915        implementation of support for (*MARK) will need an extra pointer on the
916        stack; I have reserved it now, so that the stack frame size does not
917        decrease.
918    
919    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
920        item in branch that calls a recursion is a subroutine call - as in the
921        second branch in the above example - was incorrectly given the compile-
922        time error "recursive call could loop indefinitely" because pcre_compile()
923        was not correctly checking the subroutine for matching a non-empty string.
924    
925    14. The checks for overrunning compiling workspace could trigger after an
926        overrun had occurred. This is a "should never occur" error, but it can be
927        triggered by pathological patterns such as hundreds of nested parentheses.
928        The checks now trigger 100 bytes before the end of the workspace.
929    
930    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
931    
932    
933  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
934  ------------------------  ------------------------

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