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revision 657 by ph10, Mon Aug 15 17:39:09 2011 UTC revision 740 by zherczeg, Mon Oct 31 06:10:14 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 02-Aug-2011  Version 8.21
5    ------------
6    
7    1.  Updating the JIT compiler.
8    
9    
10    Version 8.20 21-Oct-2011
11    ------------------------
12    
13    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
14        a POSIX class. After further experiments with Perl, which convinced me that
15        Perl has bugs and confusions, a closing square bracket is no longer allowed
16        in a POSIX name. This bug also affected patterns with classes that started
17        with full stops.
18    
19    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
20        captured substring, but while checking the failing first alternative,
21        substring 1 is temporarily captured. If the output vector supplied to
22        pcre_exec() was not big enough for this capture, the yield of the function
23        was still zero ("insufficient space for captured substrings"). This cannot
24        be totally fixed without adding another stack variable, which seems a lot
25        of expense for a edge case. However, I have improved the situation in cases
26        such as /(a)(b)x|abc/ matched against "abc", where the return code
27        indicates that fewer than the maximum number of slots in the ovector have
28        been set.
29    
30    3.  Related to (2) above: when there are more back references in a pattern than
31        slots in the output vector, pcre_exec() uses temporary memory during
32        matching, and copies in the captures as far as possible afterwards. It was
33        using the entire output vector, but this conflicts with the specification
34        that only 2/3 is used for passing back captured substrings. Now it uses
35        only the first 2/3, for compatibility. This is, of course, another edge
36        case.
37    
38    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
39        main code base, and can be used by building with --enable-jit. When this is
40        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
41        runtime --no-jit option is given.
42    
43    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
44        ovector, the return from the function was zero, implying that there were
45        other matches that did not fit. The correct "exactly full" value is now
46        returned.
47    
48    6.  If a subpattern that was called recursively or as a subroutine contained
49        (*PRUNE) or any other control that caused it to give a non-standard return,
50        invalid errors such as "Error -26 (nested recursion at the same subject
51        position)" or even infinite loops could occur.
52    
53    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
54        computing the minimum length on reaching *ACCEPT, and so ended up with the
55        wrong value of 1 rather than 0. Further investigation indicates that
56        computing a minimum subject length in the presence of *ACCEPT is difficult
57        (think back references, subroutine calls), and so I have changed the code
58        so that no minimum is registered for a pattern that contains *ACCEPT.
59    
60    8.  If (*THEN) was present in the first (true) branch of a conditional group,
61        it was not handled as intended. [But see 16 below.]
62    
63    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
64        Sheri Pierce.
65    
66    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
67        the first byte in a match must be "a".
68    
69    11. Change 17 for 8.13 increased the recursion depth for patterns like
70        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
71        pattern contains any instances of (*THEN). If it does not, the old
72        optimizations are restored. It would be nice to do this on a per-group
73        basis, but at the moment that is not feasible.
74    
75    12. In some environments, the output of pcretest -C is CRLF terminated. This
76        broke RunTest's code that checks for the link size. A single white space
77        character after the value is now allowed for.
78    
79    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
80        For "fr", it uses the Windows-specific input and output files.
81    
82    14. If (*THEN) appeared in a group that was called recursively or as a
83        subroutine, it did not work as intended. [But see next item.]
84    
85    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
86        pattern fragments (but not containing any | characters). If A and B are
87        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
88        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
89        D. In other words, Perl considers parentheses that do not contain any |
90        characters to be part of a surrounding alternative, whereas PCRE was
91        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
92        differently. PCRE now behaves in the same way as Perl, except in the case
93        of subroutine/recursion calls such as (?1) which have in any case always
94        been different (but PCRE had them first :-).
95    
96    16. Related to 15 above: Perl does not treat the | in a conditional group as
97        creating alternatives. Such a group is treated in the same way as an
98        ordinary group without any | characters when processing (*THEN). PCRE has
99        been changed to match Perl's behaviour.
100    
101    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
102        RunGrepTest script failed.
103    
104    18. Change 22 for version 13 caused atomic groups to use more stack. This is
105        inevitable for groups that contain captures, but it can lead to a lot of
106        stack use in large patterns. The old behaviour has been restored for atomic
107        groups that do not contain any capturing parentheses.
108    
109    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
110        suppress the check for a minimum subject length at run time. (If it was
111        given to pcre_exec() or pcre_dfa_exec() it did work.)
112    
113    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
114        fail to work when decoding hex characters in data strings in EBCDIC
115        environments.
116    
117    21. It appears that in at least one Mac OS environment, the isxdigit() function
118        is implemented as a macro that evaluates to its argument more than once,
119        contravening the C 90 Standard (I haven't checked a later standard). There
120        was an instance in pcretest which caused it to go wrong when processing
121        \x{...} escapes in subject strings. The has been rewritten to avoid using
122        things like p++ in the argument of isxdigit().
123    
124    
125    Version 8.13 16-Aug-2011
126  ------------------------  ------------------------
127    
128  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 98  Version 8.13 02-Aug-2011 Line 219  Version 8.13 02-Aug-2011
219      tail recursion to cut down on stack usage. Unfortunately, now that there is      tail recursion to cut down on stack usage. Unfortunately, now that there is
220      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
221      no longer possible because the return has to be checked for (*THEN). These      no longer possible because the return has to be checked for (*THEN). These
222      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
223    
224  18. If a pattern containing \R was studied, it was assumed that \R always  18. If a pattern containing \R was studied, it was assumed that \R always
225      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
# Line 189  Version 8.13 02-Aug-2011 Line 310  Version 8.13 02-Aug-2011
310      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
311      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
312      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
313      more like Perl.      more like Perl. (But see 8.20/1 above.)
314    
315  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
316      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).
# Line 224  Version 8.13 02-Aug-2011 Line 345  Version 8.13 02-Aug-2011
345      (a) The default value of the buffer size parameter has been increased from      (a) The default value of the buffer size parameter has been increased from
346          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
347    
348      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
349          PCRE is built.          PCRE is built.
350    
351      (c) A --buffer-size=n option has been added to pcregrep, to allow the size      (c) A --buffer-size=n option has been added to pcregrep, to allow the size
# Line 245  Version 8.13 02-Aug-2011 Line 366  Version 8.13 02-Aug-2011
366  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a  47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
367      complete match instead of a partial match. This bug was dependent on both      complete match instead of a partial match. This bug was dependent on both
368      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
369    
370  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the  48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
371      starting byte set, because \b was not being ignored.      starting byte set, because \b was not being ignored.
372    
373    
374  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011

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