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revision 654 by ph10, Tue Aug 2 11:00:40 2011 UTC revision 873 by ph10, Sat Jan 14 16:45:24 2012 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 02-Aug-2011  Version 8.30
5    ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
11        only in quite long subpatterns.
12    
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
15    
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
20    
21    5.  A reference to an unset group with zero minimum repetition was giving
22        totally wrong answers (in non-JavaScript-compatibility mode). For example,
23        /(another)?(\1?)test/ matched against "hello world test". This bug was
24        introduced in release 8.13.
25    
26    6.  Add support for 16-bit character strings (a large amount of work involving
27        many changes and refactorings).
28    
29    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31        from a file.
32    
33    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34        rounding is not applied in this particular case).
35    
36    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
38    
39    
40    Version 8.21 12-Dec-2011
41    ------------------------
42    
43    1.  Updating the JIT compiler.
44    
45    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
46        are added as well.
47    
48    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
49        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
50        calling _pcre_jit_exec. Some extra comments are added.
51    
52    4.  (*MARK) settings inside atomic groups that do not contain any capturing
53        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
54        was introduced by change 18 for 8.20.
55    
56    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
57        ECMA-262 standard.
58    
59    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
60        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
61        This bug was probably introduced by change 9 of 8.13.
62    
63    7.  While fixing 6 above, I noticed that a number of other items were being
64        incorrectly rejected as "not fixed length". This arose partly because newer
65        opcodes had not been added to the fixed-length checking code. I have (a)
66        corrected the bug and added tests for these items, and (b) arranged for an
67        error to occur if an unknown opcode is encountered while checking for fixed
68        length instead of just assuming "not fixed length". The items that were
69        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
70        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
71        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
72    
73    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
74        being incorrectly compiled and would have given unpredicatble results.
75    
76    9.  A possessively repeated subpattern with minimum repeat count greater than
77        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
78        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
79        the first (A) could occur when it should not.
80    
81    10. Add a cast and remove a redundant test from the code.
82    
83    11. JIT should use pcre_malloc/pcre_free for allocation.
84    
85    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
86        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
87        is anything other than /usr, -L is still shown).
88    
89    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
90    
91    14. Perl does not support \N without a following name in a [] class; PCRE now
92        also gives an error.
93    
94    15. If a forward reference was repeated with an upper limit of around 2000,
95        it caused the error "internal error: overran compiling workspace". The
96        maximum number of forward references (including repeats) was limited by the
97        internal workspace, and dependent on the LINK_SIZE. The code has been
98        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
99        the default depends on LINK_SIZE. There is a new upper limit (for safety)
100        of around 200,000 forward references. While doing this, I also speeded up
101        the filling in of repeated forward references.
102    
103    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
104        incorrectly expecting the subject to contain another "a" after the start.
105    
106    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
107        in the match, the SKIP should be ignored. This was not happening; instead
108        the SKIP was being treated as NOMATCH. For patterns such as
109        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
110        tested.
111    
112    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
113        now much more compatible with Perl, in particular in cases where the result
114        is a non-match for a non-anchored pattern. For example, if
115        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
116        "m", where previously it did not return a name. A side effect of this
117        change is that for partial matches, the last encountered mark name is
118        returned, as for non matches. A number of tests that were previously not
119        Perl-compatible have been moved into the Perl-compatible test files. The
120        refactoring has had the pleasing side effect of removing one argument from
121        the match() function, thus reducing its stack requirements.
122    
123    19. If the /S+ option was used in pcretest to study a pattern using JIT,
124        subsequent uses of /S (without +) incorrectly behaved like /S+.
125    
126    21. Retrieve executable code size support for the JIT compiler and fixing
127        some warnings.
128    
129    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
130        not work when the shorter character appeared right at the end of the
131        subject string.
132    
133    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
134        systems.
135    
136    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
137        output it when the /M option is used in pcretest.
138    
139    25. The CheckMan script was not being included in the distribution. Also, added
140        an explicit "perl" to run Perl scripts from the PrepareRelease script
141        because this is reportedly needed in Windows.
142    
143    26. If study data was being save in a file and studying had not found a set of
144        "starts with" bytes for the pattern, the data written to the file (though
145        never used) was taken from uninitialized memory and so caused valgrind to
146        complain.
147    
148    27. Updated RunTest.bat as provided by Sheri Pierce.
149    
150    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
151    
152    29. Computation of memory usage for the table of capturing group names was
153        giving an unnecessarily large value.
154    
155    
156    Version 8.20 21-Oct-2011
157    ------------------------
158    
159    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
160        a POSIX class. After further experiments with Perl, which convinced me that
161        Perl has bugs and confusions, a closing square bracket is no longer allowed
162        in a POSIX name. This bug also affected patterns with classes that started
163        with full stops.
164    
165    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
166        captured substring, but while checking the failing first alternative,
167        substring 1 is temporarily captured. If the output vector supplied to
168        pcre_exec() was not big enough for this capture, the yield of the function
169        was still zero ("insufficient space for captured substrings"). This cannot
170        be totally fixed without adding another stack variable, which seems a lot
171        of expense for a edge case. However, I have improved the situation in cases
172        such as /(a)(b)x|abc/ matched against "abc", where the return code
173        indicates that fewer than the maximum number of slots in the ovector have
174        been set.
175    
176    3.  Related to (2) above: when there are more back references in a pattern than
177        slots in the output vector, pcre_exec() uses temporary memory during
178        matching, and copies in the captures as far as possible afterwards. It was
179        using the entire output vector, but this conflicts with the specification
180        that only 2/3 is used for passing back captured substrings. Now it uses
181        only the first 2/3, for compatibility. This is, of course, another edge
182        case.
183    
184    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
185        main code base, and can be used by building with --enable-jit. When this is
186        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
187        runtime --no-jit option is given.
188    
189    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
190        ovector, the return from the function was zero, implying that there were
191        other matches that did not fit. The correct "exactly full" value is now
192        returned.
193    
194    6.  If a subpattern that was called recursively or as a subroutine contained
195        (*PRUNE) or any other control that caused it to give a non-standard return,
196        invalid errors such as "Error -26 (nested recursion at the same subject
197        position)" or even infinite loops could occur.
198    
199    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
200        computing the minimum length on reaching *ACCEPT, and so ended up with the
201        wrong value of 1 rather than 0. Further investigation indicates that
202        computing a minimum subject length in the presence of *ACCEPT is difficult
203        (think back references, subroutine calls), and so I have changed the code
204        so that no minimum is registered for a pattern that contains *ACCEPT.
205    
206    8.  If (*THEN) was present in the first (true) branch of a conditional group,
207        it was not handled as intended. [But see 16 below.]
208    
209    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
210        Sheri Pierce.
211    
212    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
213        the first byte in a match must be "a".
214    
215    11. Change 17 for 8.13 increased the recursion depth for patterns like
216        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
217        pattern contains any instances of (*THEN). If it does not, the old
218        optimizations are restored. It would be nice to do this on a per-group
219        basis, but at the moment that is not feasible.
220    
221    12. In some environments, the output of pcretest -C is CRLF terminated. This
222        broke RunTest's code that checks for the link size. A single white space
223        character after the value is now allowed for.
224    
225    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
226        For "fr", it uses the Windows-specific input and output files.
227    
228    14. If (*THEN) appeared in a group that was called recursively or as a
229        subroutine, it did not work as intended. [But see next item.]
230    
231    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
232        pattern fragments (but not containing any | characters). If A and B are
233        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
234        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
235        D. In other words, Perl considers parentheses that do not contain any |
236        characters to be part of a surrounding alternative, whereas PCRE was
237        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
238        differently. PCRE now behaves in the same way as Perl, except in the case
239        of subroutine/recursion calls such as (?1) which have in any case always
240        been different (but PCRE had them first :-).
241    
242    16. Related to 15 above: Perl does not treat the | in a conditional group as
243        creating alternatives. Such a group is treated in the same way as an
244        ordinary group without any | characters when processing (*THEN). PCRE has
245        been changed to match Perl's behaviour.
246    
247    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
248        RunGrepTest script failed.
249    
250    18. Change 22 for version 13 caused atomic groups to use more stack. This is
251        inevitable for groups that contain captures, but it can lead to a lot of
252        stack use in large patterns. The old behaviour has been restored for atomic
253        groups that do not contain any capturing parentheses.
254    
255    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
256        suppress the check for a minimum subject length at run time. (If it was
257        given to pcre_exec() or pcre_dfa_exec() it did work.)
258    
259    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
260        fail to work when decoding hex characters in data strings in EBCDIC
261        environments.
262    
263    21. It appears that in at least one Mac OS environment, the isxdigit() function
264        is implemented as a macro that evaluates to its argument more than once,
265        contravening the C 90 Standard (I haven't checked a later standard). There
266        was an instance in pcretest which caused it to go wrong when processing
267        \x{...} escapes in subject strings. The has been rewritten to avoid using
268        things like p++ in the argument of isxdigit().
269    
270    
271    Version 8.13 16-Aug-2011
272  ------------------------  ------------------------
273    
274  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 365  Version 8.13 02-Aug-2011
365      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
366      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
367      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
368      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
369    
370  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
371      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 456  Version 8.13 02-Aug-2011
456      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
457      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
458      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
459      more like Perl.      more like Perl. (But see 8.20/1 above.)
460    
461  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
462      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 491  Version 8.13 02-Aug-2011
491      (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
492          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
493    
494      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
495          PCRE is built.          PCRE is built.
496    
497      (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 246  Version 8.13 02-Aug-2011 Line 513  Version 8.13 02-Aug-2011
513      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
514      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
515    
516    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
517        starting byte set, because \b was not being ignored.
518    
519    
520  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
521  ------------------------  ------------------------

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