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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.10 03-Jun-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    
53    Version 8.30 04-February-2012
54    -----------------------------
55    
56    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
57        name is defined in ctype.h.
58    
59    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
60        only in quite long subpatterns.
61    
62    3.  Removed the function pcre_info(), which has been obsolete and deprecated
63        since it was replaced by pcre_fullinfo() in February 2000.
64    
65    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
66        match a (*MARK), and the match failed at the start of the subject, a
67        reference to memory before the start of the subject could occur. This bug
68        was introduced by fix 17 of release 8.21.
69    
70    5.  A reference to an unset group with zero minimum repetition was giving
71        totally wrong answers (in non-JavaScript-compatibility mode). For example,
72        /(another)?(\1?)test/ matched against "hello world test". This bug was
73        introduced in release 8.13.
74    
75    6.  Add support for 16-bit character strings (a large amount of work involving
76        many changes and refactorings).
77    
78    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
79        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
80        from a file.
81    
82    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
83        rounding is not applied in this particular case).
84    
85    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
86        if they appear, or are escaped, in patterns.
87    
88    10. Get rid of a number of -Wunused-but-set-variable warnings.
89    
90    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
91        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
92        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
93        also returns the mark "x". This bug applied to capturing parentheses,
94        non-capturing parentheses, and atomic parentheses. It also applied to some
95        assertions.
96    
97    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
98        information out of configure.ac instead of relying on pcre.h.generic, which
99        is not stored in the repository.
100    
101    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
102        -lreadline.
103    
104    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
105    
106    15. Applied Graycode's patch to put the top-level frame on the stack rather
107        than the heap when not using the stack for recursion. This gives a
108        performance improvement in many cases when recursion is not deep.
109    
110    16. Experimental code added to "pcretest -C" to output the stack frame size.
111    
112    
113    Version 8.21 12-Dec-2011
114    ------------------------
115    
116    1.  Updating the JIT compiler.
117    
118    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
119        are added as well.
120    
121    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
122        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
123        calling _pcre_jit_exec. Some extra comments are added.
124    
125    4.  (*MARK) settings inside atomic groups that do not contain any capturing
126        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
127        was introduced by change 18 for 8.20.
128    
129    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
130        ECMA-262 standard.
131    
132    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
133        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
134        This bug was probably introduced by change 9 of 8.13.
135    
136    7.  While fixing 6 above, I noticed that a number of other items were being
137        incorrectly rejected as "not fixed length". This arose partly because newer
138        opcodes had not been added to the fixed-length checking code. I have (a)
139        corrected the bug and added tests for these items, and (b) arranged for an
140        error to occur if an unknown opcode is encountered while checking for fixed
141        length instead of just assuming "not fixed length". The items that were
142        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
143        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
144        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
145    
146    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
147        being incorrectly compiled and would have given unpredicatble results.
148    
149    9.  A possessively repeated subpattern with minimum repeat count greater than
150        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
151        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
152        the first (A) could occur when it should not.
153    
154    10. Add a cast and remove a redundant test from the code.
155    
156    11. JIT should use pcre_malloc/pcre_free for allocation.
157    
158    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
159        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
160        is anything other than /usr, -L is still shown).
161    
162    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
163    
164    14. Perl does not support \N without a following name in a [] class; PCRE now
165        also gives an error.
166    
167    15. If a forward reference was repeated with an upper limit of around 2000,
168        it caused the error "internal error: overran compiling workspace". The
169        maximum number of forward references (including repeats) was limited by the
170        internal workspace, and dependent on the LINK_SIZE. The code has been
171        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
172        the default depends on LINK_SIZE. There is a new upper limit (for safety)
173        of around 200,000 forward references. While doing this, I also speeded up
174        the filling in of repeated forward references.
175    
176    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
177        incorrectly expecting the subject to contain another "a" after the start.
178    
179    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
180        in the match, the SKIP should be ignored. This was not happening; instead
181        the SKIP was being treated as NOMATCH. For patterns such as
182        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
183        tested.
184    
185    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
186        now much more compatible with Perl, in particular in cases where the result
187        is a non-match for a non-anchored pattern. For example, if
188        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
189        "m", where previously it did not return a name. A side effect of this
190        change is that for partial matches, the last encountered mark name is
191        returned, as for non matches. A number of tests that were previously not
192        Perl-compatible have been moved into the Perl-compatible test files. The
193        refactoring has had the pleasing side effect of removing one argument from
194        the match() function, thus reducing its stack requirements.
195    
196    19. If the /S+ option was used in pcretest to study a pattern using JIT,
197        subsequent uses of /S (without +) incorrectly behaved like /S+.
198    
199    21. Retrieve executable code size support for the JIT compiler and fixing
200        some warnings.
201    
202    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
203        not work when the shorter character appeared right at the end of the
204        subject string.
205    
206    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
207        systems.
208    
209    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
210        output it when the /M option is used in pcretest.
211    
212    25. The CheckMan script was not being included in the distribution. Also, added
213        an explicit "perl" to run Perl scripts from the PrepareRelease script
214        because this is reportedly needed in Windows.
215    
216    26. If study data was being save in a file and studying had not found a set of
217        "starts with" bytes for the pattern, the data written to the file (though
218        never used) was taken from uninitialized memory and so caused valgrind to
219        complain.
220    
221    27. Updated RunTest.bat as provided by Sheri Pierce.
222    
223    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
224    
225    29. Computation of memory usage for the table of capturing group names was
226        giving an unnecessarily large value.
227    
228    
229    Version 8.20 21-Oct-2011
230    ------------------------
231    
232    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
233        a POSIX class. After further experiments with Perl, which convinced me that
234        Perl has bugs and confusions, a closing square bracket is no longer allowed
235        in a POSIX name. This bug also affected patterns with classes that started
236        with full stops.
237    
238    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
239        captured substring, but while checking the failing first alternative,
240        substring 1 is temporarily captured. If the output vector supplied to
241        pcre_exec() was not big enough for this capture, the yield of the function
242        was still zero ("insufficient space for captured substrings"). This cannot
243        be totally fixed without adding another stack variable, which seems a lot
244        of expense for a edge case. However, I have improved the situation in cases
245        such as /(a)(b)x|abc/ matched against "abc", where the return code
246        indicates that fewer than the maximum number of slots in the ovector have
247        been set.
248    
249    3.  Related to (2) above: when there are more back references in a pattern than
250        slots in the output vector, pcre_exec() uses temporary memory during
251        matching, and copies in the captures as far as possible afterwards. It was
252        using the entire output vector, but this conflicts with the specification
253        that only 2/3 is used for passing back captured substrings. Now it uses
254        only the first 2/3, for compatibility. This is, of course, another edge
255        case.
256    
257    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
258        main code base, and can be used by building with --enable-jit. When this is
259        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
260        runtime --no-jit option is given.
261    
262    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
263        ovector, the return from the function was zero, implying that there were
264        other matches that did not fit. The correct "exactly full" value is now
265        returned.
266    
267    6.  If a subpattern that was called recursively or as a subroutine contained
268        (*PRUNE) or any other control that caused it to give a non-standard return,
269        invalid errors such as "Error -26 (nested recursion at the same subject
270        position)" or even infinite loops could occur.
271    
272    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
273        computing the minimum length on reaching *ACCEPT, and so ended up with the
274        wrong value of 1 rather than 0. Further investigation indicates that
275        computing a minimum subject length in the presence of *ACCEPT is difficult
276        (think back references, subroutine calls), and so I have changed the code
277        so that no minimum is registered for a pattern that contains *ACCEPT.
278    
279    8.  If (*THEN) was present in the first (true) branch of a conditional group,
280        it was not handled as intended. [But see 16 below.]
281    
282    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
283        Sheri Pierce.
284    
285    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
286        the first byte in a match must be "a".
287    
288    11. Change 17 for 8.13 increased the recursion depth for patterns like
289        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
290        pattern contains any instances of (*THEN). If it does not, the old
291        optimizations are restored. It would be nice to do this on a per-group
292        basis, but at the moment that is not feasible.
293    
294    12. In some environments, the output of pcretest -C is CRLF terminated. This
295        broke RunTest's code that checks for the link size. A single white space
296        character after the value is now allowed for.
297    
298    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
299        For "fr", it uses the Windows-specific input and output files.
300    
301    14. If (*THEN) appeared in a group that was called recursively or as a
302        subroutine, it did not work as intended. [But see next item.]
303    
304    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
305        pattern fragments (but not containing any | characters). If A and B are
306        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
307        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
308        D. In other words, Perl considers parentheses that do not contain any |
309        characters to be part of a surrounding alternative, whereas PCRE was
310        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
311        differently. PCRE now behaves in the same way as Perl, except in the case
312        of subroutine/recursion calls such as (?1) which have in any case always
313        been different (but PCRE had them first :-).
314    
315    16. Related to 15 above: Perl does not treat the | in a conditional group as
316        creating alternatives. Such a group is treated in the same way as an
317        ordinary group without any | characters when processing (*THEN). PCRE has
318        been changed to match Perl's behaviour.
319    
320    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
321        RunGrepTest script failed.
322    
323    18. Change 22 for version 13 caused atomic groups to use more stack. This is
324        inevitable for groups that contain captures, but it can lead to a lot of
325        stack use in large patterns. The old behaviour has been restored for atomic
326        groups that do not contain any capturing parentheses.
327    
328    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
329        suppress the check for a minimum subject length at run time. (If it was
330        given to pcre_exec() or pcre_dfa_exec() it did work.)
331    
332    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
333        fail to work when decoding hex characters in data strings in EBCDIC
334        environments.
335    
336    21. It appears that in at least one Mac OS environment, the isxdigit() function
337        is implemented as a macro that evaluates to its argument more than once,
338        contravening the C 90 Standard (I haven't checked a later standard). There
339        was an instance in pcretest which caused it to go wrong when processing
340        \x{...} escapes in subject strings. The has been rewritten to avoid using
341        things like p++ in the argument of isxdigit().
342    
343    
344    Version 8.13 16-Aug-2011
345    ------------------------
346    
347    1.  The Unicode data tables have been updated to Unicode 6.0.0.
348    
349    2.  Two minor typos in pcre_internal.h have been fixed.
350    
351    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
352        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
353        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
354    
355    4.  There were a number of related bugs in the code for matching backrefences
356        caselessly in UTF-8 mode when codes for the characters concerned were
357        different numbers of bytes. For example, U+023A and U+2C65 are an upper
358        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
359        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
360        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
361        2-byte code at the end of the subject (it thought there wasn't enough data
362        left).
363    
364    5.  Comprehensive information about what went wrong is now returned by
365        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
366        as the output vector has at least 2 elements. The offset of the start of
367        the failing character and a reason code are placed in the vector.
368    
369    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
370        now returned is for the first byte of the failing character, instead of the
371        last byte inspected. This is an incompatible change, but I hope it is small
372        enough not to be a problem. It makes the returned offset consistent with
373        pcre_exec() and pcre_dfa_exec().
374    
375    7.  pcretest now gives a text phrase as well as the error number when
376        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
377        failure, the offset and reason code are output.
378    
379    8.  When \R was used with a maximizing quantifier it failed to skip backwards
380        over a \r\n pair if the subsequent match failed. Instead, it just skipped
381        back over a single character (\n). This seems wrong (because it treated the
382        two characters as a single entity when going forwards), conflicts with the
383        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
384        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
385        has been changed.
386    
387    9.  Some internal refactoring has changed the processing so that the handling
388        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
389        time (the PCRE_DOTALL option was changed this way some time ago: version
390        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
391        which was always a bit of a fudge. It also means that there is one less
392        argument for the match() function, which reduces its stack requirements
393        slightly. This change also fixes an incompatibility with Perl: the pattern
394        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
395    
396    10. More internal refactoring has drastically reduced the number of recursive
397        calls to match() for possessively repeated groups such as (abc)++ when
398        using pcre_exec().
399    
400    11. While implementing 10, a number of bugs in the handling of groups were
401        discovered and fixed:
402    
403        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
404        (a|)*(?1) gave a compile-time internal error.
405        ((a|)+)+  did not notice that the outer group could match an empty string.
406        (^a|^)+   was not marked as anchored.
407        (.*a|.*)+ was not marked as matching at start or after a newline.
408    
409    12. Yet more internal refactoring has removed another argument from the match()
410        function. Special calls to this function are now indicated by setting a
411        value in a variable in the "match data" data block.
412    
413    13. Be more explicit in pcre_study() instead of relying on "default" for
414        opcodes that mean there is no starting character; this means that when new
415        ones are added and accidentally left out of pcre_study(), testing should
416        pick them up.
417    
418    14. The -s option of pcretest has been documented for ages as being an old
419        synonym of -m (show memory usage). I have changed it to mean "force study
420        for every regex", that is, assume /S for every regex. This is similar to -i
421        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
422        using it. It makes it easier to run collections of tests with and without
423        study enabled, and thereby test pcre_study() more easily. All the standard
424        tests are now run with and without -s (but some patterns can be marked as
425        "never study" - see 20 below).
426    
427    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
428        restoration of the capturing data to the outer values was not happening
429        correctly.
430    
431    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
432        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
433        pattern had matched an empty string, and so incorrectly returned a no
434        match.
435    
436    17. There was optimizing code for the last branch of non-capturing parentheses,
437        and also for the obeyed branch of a conditional subexpression, which used
438        tail recursion to cut down on stack usage. Unfortunately, now that there is
439        the possibility of (*THEN) occurring in these branches, tail recursion is
440        no longer possible because the return has to be checked for (*THEN). These
441        two optimizations have therefore been removed. [But see 8.20/11 above.]
442    
443    18. If a pattern containing \R was studied, it was assumed that \R always
444        matched two bytes, thus causing the minimum subject length to be
445        incorrectly computed because \R can also match just one byte.
446    
447    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
448        was incorrectly computed.
449    
450    20. If /S is present twice on a test pattern in pcretest input, it now
451        *disables* studying, thereby overriding the use of -s on the command line
452        (see 14 above). This is necessary for one or two tests to keep the output
453        identical in both cases.
454    
455    21. When (*ACCEPT) was used in an assertion that matched an empty string and
456        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
457    
458    22. When an atomic group that contained a capturing parenthesis was
459        successfully matched, but the branch in which it appeared failed, the
460        capturing was not being forgotten if a higher numbered group was later
461        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
462        group 1 to "a", when in fact it should be unset. This applied to multi-
463        branched capturing and non-capturing groups, repeated or not, and also to
464        positive assertions (capturing in negative assertions does not happen
465        in PCRE) and also to nested atomic groups.
466    
467    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
468        subject after a captured substring, to make it easier to tell which of a
469        number of identical substrings has been captured.
470    
471    24. The way atomic groups are processed by pcre_exec() has been changed so that
472        if they are repeated, backtracking one repetition now resets captured
473        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
474        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
475        "aaa". Previously, it would have been "a". As part of this code
476        refactoring, the way recursive calls are handled has also been changed.
477    
478    25. If an assertion condition captured any substrings, they were not passed
479        back unless some other capturing happened later. For example, if
480        (?(?=(a))a) was matched against "a", no capturing was returned.
481    
482    26. When studying a pattern that contained subroutine calls or assertions,
483        the code for finding the minimum length of a possible match was handling
484        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
485        group 1 called group 2 while simultaneously a separate group 2 called group
486        1). A stack overflow occurred in this case. I have fixed this by limiting
487        the recursion depth to 10.
488    
489    27. Updated RunTest.bat in the distribution to the version supplied by Tom
490        Fortmann. This supports explicit test numbers on the command line, and has
491        argument validation and error reporting.
492    
493    28. An instance of \X with an unlimited repeat could fail if at any point the
494        first character it looked at was a mark character.
495    
496    29. Some minor code refactoring concerning Unicode properties and scripts
497        should reduce the stack requirement of match() slightly.
498    
499    30. Added the '=' option to pcretest to check the setting of unused capturing
500        slots at the end of the pattern, which are documented as being -1, but are
501        not included in the return count.
502    
503    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
504        compiled something random. Now it gives a compile-time error (as does
505        Perl).
506    
507    32. A *MARK encountered during the processing of a positive assertion is now
508        recorded and passed back (compatible with Perl).
509    
510    33. If --only-matching or --colour was set on a pcregrep call whose pattern
511        had alternative anchored branches, the search for a second match in a line
512        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
513        matched the line "0102" twice. The same bug affected patterns that started
514        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
515        twice.
516    
517    34. Previously, PCRE did not allow quantification of assertions. However, Perl
518        does, and because of capturing effects, quantifying parenthesized
519        assertions may at times be useful. Quantifiers are now allowed for
520        parenthesized assertions.
521    
522    35. A minor code tidy in pcre_compile() when checking options for \R usage.
523    
524    36. \g was being checked for fancy things in a character class, when it should
525        just be a literal "g".
526    
527    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
528        appearance of a nested POSIX class supersedes an apparent external class.
529        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
530        unescaped square brackets may also appear as part of class names. For
531        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
532        more like Perl. (But see 8.20/1 above.)
533    
534    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
535        was because it thought it was \N{name}, which is not supported).
536    
537    39. Add minix to OS list not supporting the -S option in pcretest.
538    
539    40. PCRE tries to detect cases of infinite recursion at compile time, but it
540        cannot analyze patterns in sufficient detail to catch mutual recursions
541        such as ((?1))((?2)). There is now a runtime test that gives an error if a
542        subgroup is called recursively as a subpattern for a second time at the
543        same position in the subject string. In previous releases this might have
544        been caught by the recursion limit, or it might have run out of stack.
545    
546    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
547        happen only once. PCRE was, however incorrectly giving a compile time error
548        "recursive call could loop indefinitely" because it cannot analyze the
549        pattern in sufficient detail. The compile time test no longer happens when
550        PCRE is compiling a conditional subpattern, but actual runaway loops are
551        now caught at runtime (see 40 above).
552    
553    42. It seems that Perl allows any characters other than a closing parenthesis
554        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
555        has been changed to be the same.
556    
557    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
558        as not to get warnings when autogen.sh is called. Also changed
559        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
560    
561    44. To help people who use pcregrep to scan files containing exceedingly long
562        lines, the following changes have been made:
563    
564        (a) The default value of the buffer size parameter has been increased from
565            8K to 20K. (The actual buffer used is three times this size.)
566    
567        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
568            PCRE is built.
569    
570        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
571            to be set at run time.
572    
573        (d) Numerical values in pcregrep options can be followed by K or M, for
574            example --buffer-size=50K.
575    
576        (e) If a line being scanned overflows pcregrep's buffer, an error is now
577            given and the return code is set to 2.
578    
579    45. Add a pointer to the latest mark to the callout data block.
580    
581    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
582        partial match of an empty string instead of no match. This was specific to
583        the use of ".".
584    
585    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
586        complete match instead of a partial match. This bug was dependent on both
587        the PCRE_UTF8 and PCRE_DOTALL options being set.
588    
589    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
590        starting byte set, because \b was not being ignored.
591    
592    
593    Version 8.12 15-Jan-2011
594    ------------------------
595    
596    1.  Fixed some typos in the markup of the man pages, and wrote a script that
597        checks for such things as part of the documentation building process.
598    
599    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
600        --match-limit and --recursion-limit options (added for 8.11). In
601        particular, this made one of the standard tests fail. (The integer value
602        went into the wrong half of a long int.)
603    
604    3.  If the --colour option was given to pcregrep with -v (invert match), it
605        did strange things, either producing crazy output, or crashing. It should,
606        of course, ignore a request for colour when reporting lines that do not
607        match.
608    
609    4.  Another pcregrep bug caused similar problems if --colour was specified with
610        -M (multiline) and the pattern match finished with a line ending.
611    
612    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
613        matched in multiline mode, the following line was shown as part of the
614        match. This seems wrong, so I have changed it.
615    
616    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
617        the check for further matches in the same line (so they could be coloured)
618        to overrun the end of the current line. If another match was found, it was
619        incorrectly shown (and then shown again when found in the next line).
620    
621    7.  If pcregrep was compiled under Windows, there was a reference to the
622        function pcregrep_exit() before it was defined. I am assuming this was
623        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
624        reported by a user. I've moved the definition above the reference.
625    
626    
627    Version 8.11 10-Dec-2010
628    ------------------------
629    
630    1.  (*THEN) was not working properly if there were untried alternatives prior
631        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
632        backtracked to try for "b" instead of moving to the next alternative branch
633        at the same level (in this case, to look for "c"). The Perl documentation
634        is clear that when (*THEN) is backtracked onto, it goes to the "next
635        alternative in the innermost enclosing group".
636    
637    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
638        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
639        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
640        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
641        (*THEN).
642    
643    3.  If \s appeared in a character class, it removed the VT character from
644        the class, even if it had been included by some previous item, for example
645        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
646        of \s, but is part of the POSIX "space" class.)
647    
648    4.  A partial match never returns an empty string (because you can always
649        match an empty string at the end of the subject); however the checking for
650        an empty string was starting at the "start of match" point. This has been
651        changed to the "earliest inspected character" point, because the returned
652        data for a partial match starts at this character. This means that, for
653        example, /(?<=abc)def/ gives a partial match for the subject "abc"
654        (previously it gave "no match").
655    
656    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
657        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
658        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
659        has an implication that the given string is incomplete (because a partial
660        match is preferred over a full match). For this reason, these items now
661        give a partial match in this situation. [Aside: previously, the one case
662        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
663        match rather than a full match, which was wrong by the old rules, but is
664        now correct.]
665    
666    6.  There was a bug in the handling of #-introduced comments, recognized when
667        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
668        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
669        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
670        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
671        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
672        places in pcre_compile().
673    
674    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
675        comments when looking ahead for named forward references to subpatterns,
676        the only newline sequence it recognized was NL. It now handles newlines
677        according to the set newline convention.
678    
679    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
680        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
681        cater for a lack of strerror(). These oversights have been fixed.
682    
683    9.  Added --match-limit and --recursion-limit to pcregrep.
684    
685    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
686    
687    11. When the -o option was used, pcregrep was setting a return code of 1, even
688        when matches were found, and --line-buffered was not being honoured.
689    
690    12. Added an optional parentheses number to the -o and --only-matching options
691        of pcregrep.
692    
693    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
694        can match an empty string. The code to do it in pcretest and pcredemo
695        needed fixing:
696    
697        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
698            only one byte after an empty string match just before CRLF (this case
699            just got forgotten; "any" and "anycrlf" were OK).
700    
701        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
702            mode when an empty string match preceded an ASCII character followed by
703            a non-ASCII character. (The code for advancing by one character rather
704            than one byte was nonsense.)
705    
706        (c) The pcredemo.c sample program did not have any code at all to handle
707            the cases when CRLF is a valid newline sequence.
708    
709    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
710        as a starting offset was within the subject string. There is now a new
711        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
712        negative or greater than the length of the string. In order to test this,
713        pcretest is extended to allow the setting of negative starting offsets.
714    
715    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
716        starting offset points to the beginning of a UTF-8 character was
717        unnecessarily clumsy. I tidied it up.
718    
719    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
720        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
721    
722    17. Nobody had reported that the --include_dir option, which was added in
723        release 7.7 should have been called --include-dir (hyphen, not underscore)
724        for compatibility with GNU grep. I have changed it to --include-dir, but
725        left --include_dir as an undocumented synonym, and the same for
726        --exclude-dir, though that is not available in GNU grep, at least as of
727        release 2.5.4.
728    
729    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
730        characters from a string of bytes) have been redefined so as not to use
731        loops, in order to improve performance in some environments. At the same
732        time, I abstracted some of the common code into auxiliary macros to save
733        repetition (this should not affect the compiled code).
734    
735    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
736        compile-time error is now given if \c is not followed by an ASCII
737        character, that is, a byte less than 128. (In EBCDIC mode, the code is
738        different, and any byte value is allowed.)
739    
740    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
741        START_OPTIMIZE option, which is now allowed at compile time - but just
742        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
743        to pcregrep and other applications that have no direct access to PCRE
744        options. The new /Y option in pcretest sets this option when calling
745        pcre_compile().
746    
747    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
748        back references. Groups containing recursive back references were forced to
749        be atomic by that change, but in the case of named groups, the amount of
750        memory required was incorrectly computed, leading to "Failed: internal
751        error: code overflow". This has been fixed.
752    
753    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
754        pcretest.c, to avoid build problems in some Borland environments.
755    
756    
757    Version 8.10 25-Jun-2010
758  ------------------------  ------------------------
759    
760  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
# Line 42  Version 8.10 03-Jun-2010 Line 795  Version 8.10 03-Jun-2010
795  11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was  11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
796      studied, and the match started with a letter with a code point greater than      studied, and the match started with a letter with a code point greater than
797      127 whose first byte was different to the first byte of the other case of      127 whose first byte was different to the first byte of the other case of
798      the letter, the other case of this starting letter was not recognized      the letter, the other case of this starting letter was not recognized
799      (#976).      (#976).
800    
801  12. If a pattern that was studied started with a repeated Unicode property  12. If a pattern that was studied started with a repeated Unicode property
# Line 68  Version 8.10 03-Jun-2010 Line 821  Version 8.10 03-Jun-2010
821    
822  17. Added a check for running out of memory when PCRE is compiled with  17. Added a check for running out of memory when PCRE is compiled with
823      --disable-stack-for-recursion (#990).      --disable-stack-for-recursion (#990).
824    
825    18. If the last data line in a file for pcretest does not have a newline on
826        the end, a newline was missing in the output.
827    
828    19. The default pcre_chartables.c file recognizes only ASCII characters (values
829        less than 128) in its various bitmaps. However, there is a facility for
830        generating tables according to the current locale when PCRE is compiled. It
831        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
832        characters, are recognized by isspace() and therefore were getting set in
833        these tables, and indeed these tables seem to approximate to ISO 8859. This
834        caused a problem in UTF-8 mode when pcre_study() was used to create a list
835        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
836        which of course cannot start UTF-8 characters. I have changed the code so
837        that only real ASCII characters (less than 128) and the correct starting
838        bytes for UTF-8 encodings are set for characters greater than 127 when in
839        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
840        altogether.)
841    
842    20. Added the /T option to pcretest so as to be able to run tests with non-
843        standard character tables, thus making it possible to include the tests
844        used for 19 above in the standard set of tests.
845    
846    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
847        reference to a subpattern the other side of a comment that contains an
848        opening parenthesis caused either an internal compiling error, or a
849        reference to the wrong subpattern.
850    
851    
852  Version 8.02 19-Mar-2010  Version 8.02 19-Mar-2010

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