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revision 702 by ph10, Tue Sep 20 15:45:06 2011 UTC revision 842 by ph10, Sat Dec 31 15:19:04 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.20 12-Sep-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 the code for calculating the fixed length of lookbehind
11        assertions.
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    
34    Version 8.21 12-Dec-2011
35    ------------------------
36    
37    1.  Updating the JIT compiler.
38    
39    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
40        are added as well.
41    
42    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
43        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
44        calling _pcre_jit_exec. Some extra comments are added.
45    
46    4.  (*MARK) settings inside atomic groups that do not contain any capturing
47        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
48        was introduced by change 18 for 8.20.
49    
50    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
51        ECMA-262 standard.
52    
53    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
54        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
55        This bug was probably introduced by change 9 of 8.13.
56    
57    7.  While fixing 6 above, I noticed that a number of other items were being
58        incorrectly rejected as "not fixed length". This arose partly because newer
59        opcodes had not been added to the fixed-length checking code. I have (a)
60        corrected the bug and added tests for these items, and (b) arranged for an
61        error to occur if an unknown opcode is encountered while checking for fixed
62        length instead of just assuming "not fixed length". The items that were
63        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
64        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
65        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
66    
67    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
68        being incorrectly compiled and would have given unpredicatble results.
69    
70    9.  A possessively repeated subpattern with minimum repeat count greater than
71        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
72        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
73        the first (A) could occur when it should not.
74    
75    10. Add a cast and remove a redundant test from the code.
76    
77    11. JIT should use pcre_malloc/pcre_free for allocation.
78    
79    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
80        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
81        is anything other than /usr, -L is still shown).
82    
83    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
84    
85    14. Perl does not support \N without a following name in a [] class; PCRE now
86        also gives an error.
87    
88    15. If a forward reference was repeated with an upper limit of around 2000,
89        it caused the error "internal error: overran compiling workspace". The
90        maximum number of forward references (including repeats) was limited by the
91        internal workspace, and dependent on the LINK_SIZE. The code has been
92        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
93        the default depends on LINK_SIZE. There is a new upper limit (for safety)
94        of around 200,000 forward references. While doing this, I also speeded up
95        the filling in of repeated forward references.
96    
97    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
98        incorrectly expecting the subject to contain another "a" after the start.
99    
100    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
101        in the match, the SKIP should be ignored. This was not happening; instead
102        the SKIP was being treated as NOMATCH. For patterns such as
103        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
104        tested.
105    
106    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
107        now much more compatible with Perl, in particular in cases where the result
108        is a non-match for a non-anchored pattern. For example, if
109        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
110        "m", where previously it did not return a name. A side effect of this
111        change is that for partial matches, the last encountered mark name is
112        returned, as for non matches. A number of tests that were previously not
113        Perl-compatible have been moved into the Perl-compatible test files. The
114        refactoring has had the pleasing side effect of removing one argument from
115        the match() function, thus reducing its stack requirements.
116    
117    19. If the /S+ option was used in pcretest to study a pattern using JIT,
118        subsequent uses of /S (without +) incorrectly behaved like /S+.
119    
120    21. Retrieve executable code size support for the JIT compiler and fixing
121        some warnings.
122    
123    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
124        not work when the shorter character appeared right at the end of the
125        subject string.
126    
127    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
128        systems.
129    
130    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
131        output it when the /M option is used in pcretest.
132    
133    25. The CheckMan script was not being included in the distribution. Also, added
134        an explicit "perl" to run Perl scripts from the PrepareRelease script
135        because this is reportedly needed in Windows.
136    
137    26. If study data was being save in a file and studying had not found a set of
138        "starts with" bytes for the pattern, the data written to the file (though
139        never used) was taken from uninitialized memory and so caused valgrind to
140        complain.
141    
142    27. Updated RunTest.bat as provided by Sheri Pierce.
143    
144    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
145    
146    29. Computation of memory usage for the table of capturing group names was
147        giving an unnecessarily large value.
148    
149    
150    Version 8.20 21-Oct-2011
151  ------------------------  ------------------------
152    
153  1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had  1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
# Line 9  Version 8.20 12-Sep-2011 Line 155  Version 8.20 12-Sep-2011
155      Perl has bugs and confusions, a closing square bracket is no longer allowed      Perl has bugs and confusions, a closing square bracket is no longer allowed
156      in a POSIX name. This bug also affected patterns with classes that started      in a POSIX name. This bug also affected patterns with classes that started
157      with full stops.      with full stops.
158    
159  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
160      captured substring, but while checking the failing first alternative,      captured substring, but while checking the failing first alternative,
161      substring 1 is temporarily captured. If the output vector supplied to      substring 1 is temporarily captured. If the output vector supplied to
# Line 20  Version 8.20 12-Sep-2011 Line 166  Version 8.20 12-Sep-2011
166      such as /(a)(b)x|abc/ matched against "abc", where the return code      such as /(a)(b)x|abc/ matched against "abc", where the return code
167      indicates that fewer than the maximum number of slots in the ovector have      indicates that fewer than the maximum number of slots in the ovector have
168      been set.      been set.
169    
170  3.  Related to (2) above: when there are more back references in a pattern than  3.  Related to (2) above: when there are more back references in a pattern than
171      slots in the output vector, pcre_exec() uses temporary memory during      slots in the output vector, pcre_exec() uses temporary memory during
172      matching, and copies in the captures as far as possible afterwards. It was      matching, and copies in the captures as far as possible afterwards. It was
# Line 28  Version 8.20 12-Sep-2011 Line 174  Version 8.20 12-Sep-2011
174      that only 2/3 is used for passing back captured substrings. Now it uses      that only 2/3 is used for passing back captured substrings. Now it uses
175      only the first 2/3, for compatibility. This is, of course, another edge      only the first 2/3, for compatibility. This is, of course, another edge
176      case.      case.
177    
178  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
179      main code base, and can be used by building with --enable-jit. When this is      main code base, and can be used by building with --enable-jit. When this is
180      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
181      runtime --no-jit option is given.      runtime --no-jit option is given.
182    
183  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
184      ovector, the return from the function was zero, implying that there were      ovector, the return from the function was zero, implying that there were
185      other matches that did not fit. The correct "exactly full" value is now      other matches that did not fit. The correct "exactly full" value is now
186      returned.      returned.
187    
188  6.  If a subpattern that was called recursively or as a subroutine contained  6.  If a subpattern that was called recursively or as a subroutine contained
189      (*PRUNE) or any other control that caused it to give a non-standard return,      (*PRUNE) or any other control that caused it to give a non-standard return,
190      invalid errors such as "Error -26 (nested recursion at the same subject      invalid errors such as "Error -26 (nested recursion at the same subject
191      position)" or even infinite loops could occur.      position)" or even infinite loops could occur.
192    
193  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
194      computing the minimum length on reaching *ACCEPT, and so ended up with the      computing the minimum length on reaching *ACCEPT, and so ended up with the
195      wrong value of 1 rather than 0. Further investigation indicates that      wrong value of 1 rather than 0. Further investigation indicates that
196      computing a minimum subject length in the presence of *ACCEPT is difficult      computing a minimum subject length in the presence of *ACCEPT is difficult
197      (think back references, subroutine calls), and so I have changed the code      (think back references, subroutine calls), and so I have changed the code
198      so that no minimum is registered for a pattern that contains *ACCEPT.      so that no minimum is registered for a pattern that contains *ACCEPT.
199    
200  8.  If (*THEN) was present in the first (true) branch of a conditional group,  8.  If (*THEN) was present in the first (true) branch of a conditional group,
201      it was not handled as intended.      it was not handled as intended. [But see 16 below.]
202    
203  9.  Replaced RunTest.bat with the much improved version provided by Sheri  9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
204      Pierce.      Sheri Pierce.
205    
206  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
207      the first byte in a match must be "a".      the first byte in a match must be "a".
208    
209  11. Change 17 for 8.13 increased the recursion depth for patterns like  11. Change 17 for 8.13 increased the recursion depth for patterns like
210      /a(?:.)*?a/ drastically. I've improved things by remembering whether a      /a(?:.)*?a/ drastically. I've improved things by remembering whether a
211      pattern contains any instances of (*THEN). If it does not, the old      pattern contains any instances of (*THEN). If it does not, the old
212      optimizations are restored. It would be nice to do this on a per-group      optimizations are restored. It would be nice to do this on a per-group
213      basis, but at the moment that is not feasible.      basis, but at the moment that is not feasible.
214    
215    12. In some environments, the output of pcretest -C is CRLF terminated. This
216        broke RunTest's code that checks for the link size. A single white space
217        character after the value is now allowed for.
218    
219    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
220        For "fr", it uses the Windows-specific input and output files.
221    
222    14. If (*THEN) appeared in a group that was called recursively or as a
223        subroutine, it did not work as intended. [But see next item.]
224    
225    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
226        pattern fragments (but not containing any | characters). If A and B are
227        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
228        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
229        D. In other words, Perl considers parentheses that do not contain any |
230        characters to be part of a surrounding alternative, whereas PCRE was
231        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
232        differently. PCRE now behaves in the same way as Perl, except in the case
233        of subroutine/recursion calls such as (?1) which have in any case always
234        been different (but PCRE had them first :-).
235    
236    16. Related to 15 above: Perl does not treat the | in a conditional group as
237        creating alternatives. Such a group is treated in the same way as an
238        ordinary group without any | characters when processing (*THEN). PCRE has
239        been changed to match Perl's behaviour.
240    
241    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
242        RunGrepTest script failed.
243    
244    18. Change 22 for version 13 caused atomic groups to use more stack. This is
245        inevitable for groups that contain captures, but it can lead to a lot of
246        stack use in large patterns. The old behaviour has been restored for atomic
247        groups that do not contain any capturing parentheses.
248    
249    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
250        suppress the check for a minimum subject length at run time. (If it was
251        given to pcre_exec() or pcre_dfa_exec() it did work.)
252    
253    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
254        fail to work when decoding hex characters in data strings in EBCDIC
255        environments.
256    
257    21. It appears that in at least one Mac OS environment, the isxdigit() function
258        is implemented as a macro that evaluates to its argument more than once,
259        contravening the C 90 Standard (I haven't checked a later standard). There
260        was an instance in pcretest which caused it to go wrong when processing
261        \x{...} escapes in subject strings. The has been rewritten to avoid using
262        things like p++ in the argument of isxdigit().
263    
264    
265  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
266  ------------------------  ------------------------

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