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revision 699 by ph10, Tue Sep 20 10:46:54 2011 UTC revision 889 by ph10, Tue Jan 17 14:51:50 2012 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 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    10. Get rid of a number of -Wunused-but-set-variable warnings.
40    
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses. It also applied to some
46        assertions.
47    
48    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49        information out of configure.ac instead of relying on pcre.h.generic, which
50        is not stored in the repository.
51    
52    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53        -lreadline.
54    
55    
56    Version 8.21 12-Dec-2011
57    ------------------------
58    
59    1.  Updating the JIT compiler.
60    
61    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
62        are added as well.
63    
64    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
65        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
66        calling _pcre_jit_exec. Some extra comments are added.
67    
68    4.  (*MARK) settings inside atomic groups that do not contain any capturing
69        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
70        was introduced by change 18 for 8.20.
71    
72    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
73        ECMA-262 standard.
74    
75    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
76        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
77        This bug was probably introduced by change 9 of 8.13.
78    
79    7.  While fixing 6 above, I noticed that a number of other items were being
80        incorrectly rejected as "not fixed length". This arose partly because newer
81        opcodes had not been added to the fixed-length checking code. I have (a)
82        corrected the bug and added tests for these items, and (b) arranged for an
83        error to occur if an unknown opcode is encountered while checking for fixed
84        length instead of just assuming "not fixed length". The items that were
85        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
86        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
87        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
88    
89    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
90        being incorrectly compiled and would have given unpredicatble results.
91    
92    9.  A possessively repeated subpattern with minimum repeat count greater than
93        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
94        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
95        the first (A) could occur when it should not.
96    
97    10. Add a cast and remove a redundant test from the code.
98    
99    11. JIT should use pcre_malloc/pcre_free for allocation.
100    
101    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
102        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
103        is anything other than /usr, -L is still shown).
104    
105    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
106    
107    14. Perl does not support \N without a following name in a [] class; PCRE now
108        also gives an error.
109    
110    15. If a forward reference was repeated with an upper limit of around 2000,
111        it caused the error "internal error: overran compiling workspace". The
112        maximum number of forward references (including repeats) was limited by the
113        internal workspace, and dependent on the LINK_SIZE. The code has been
114        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
115        the default depends on LINK_SIZE. There is a new upper limit (for safety)
116        of around 200,000 forward references. While doing this, I also speeded up
117        the filling in of repeated forward references.
118    
119    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
120        incorrectly expecting the subject to contain another "a" after the start.
121    
122    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
123        in the match, the SKIP should be ignored. This was not happening; instead
124        the SKIP was being treated as NOMATCH. For patterns such as
125        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
126        tested.
127    
128    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
129        now much more compatible with Perl, in particular in cases where the result
130        is a non-match for a non-anchored pattern. For example, if
131        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
132        "m", where previously it did not return a name. A side effect of this
133        change is that for partial matches, the last encountered mark name is
134        returned, as for non matches. A number of tests that were previously not
135        Perl-compatible have been moved into the Perl-compatible test files. The
136        refactoring has had the pleasing side effect of removing one argument from
137        the match() function, thus reducing its stack requirements.
138    
139    19. If the /S+ option was used in pcretest to study a pattern using JIT,
140        subsequent uses of /S (without +) incorrectly behaved like /S+.
141    
142    21. Retrieve executable code size support for the JIT compiler and fixing
143        some warnings.
144    
145    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
146        not work when the shorter character appeared right at the end of the
147        subject string.
148    
149    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
150        systems.
151    
152    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
153        output it when the /M option is used in pcretest.
154    
155    25. The CheckMan script was not being included in the distribution. Also, added
156        an explicit "perl" to run Perl scripts from the PrepareRelease script
157        because this is reportedly needed in Windows.
158    
159    26. If study data was being save in a file and studying had not found a set of
160        "starts with" bytes for the pattern, the data written to the file (though
161        never used) was taken from uninitialized memory and so caused valgrind to
162        complain.
163    
164    27. Updated RunTest.bat as provided by Sheri Pierce.
165    
166    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
167    
168    29. Computation of memory usage for the table of capturing group names was
169        giving an unnecessarily large value.
170    
171    
172    Version 8.20 21-Oct-2011
173  ------------------------  ------------------------
174    
175  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
176     a POSIX class. After further experiments with Perl, which convinced me that      a POSIX class. After further experiments with Perl, which convinced me that
177     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
178     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
179     with full stops.      with full stops.
180    
181  2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no captured  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
182     substring, but while checking the failing first alternative, substring 1 is      captured substring, but while checking the failing first alternative,
183     temporarily captured. If the output vector supplied to pcre_exec() was not      substring 1 is temporarily captured. If the output vector supplied to
184     big enough for this capture, the yield of the function was still zero      pcre_exec() was not big enough for this capture, the yield of the function
185     ("insufficient space for captured substrings"). This cannot be totally fixed      was still zero ("insufficient space for captured substrings"). This cannot
186     without adding another stack variable, which seems a lot of expense for a      be totally fixed without adding another stack variable, which seems a lot
187     edge case. However, I have improved the situation in cases such as      of expense for a edge case. However, I have improved the situation in cases
188     /(a)(b)x|abc/ matched against "abc", where the return code indicates that      such as /(a)(b)x|abc/ matched against "abc", where the return code
189     fewer than the maximum number of slots in the ovector have been set.      indicates that fewer than the maximum number of slots in the ovector have
190        been set.
191  3. Related to (2) above: when there are more back references in a pattern than  
192     slots in the output vector, pcre_exec() uses temporary memory during  3.  Related to (2) above: when there are more back references in a pattern than
193     matching, and copies in the captures as far as possible afterwards. It was      slots in the output vector, pcre_exec() uses temporary memory during
194     using the entire output vector, but this conflicts with the specification      matching, and copies in the captures as far as possible afterwards. It was
195     that only 2/3 is used for passing back captured substrings. Now it uses only      using the entire output vector, but this conflicts with the specification
196     the first 2/3, for compatibility. This is, of course, another edge case.      that only 2/3 is used for passing back captured substrings. Now it uses
197        only the first 2/3, for compatibility. This is, of course, another edge
198  4. Zoltan Herczeg's just-in-time compiler support has been integrated into the      case.
199     main code base, and can be used by building with --enable-jit. When this is  
200     done, pcregrep automatically uses it unless --disable-pcregrep-jit or the  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
201     runtime --no-jit option is given.      main code base, and can be used by building with --enable-jit. When this is
202        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
203  5. When the number of matches in a pcre_dfa_exec() run exactly filled the      runtime --no-jit option is given.
204     ovector, the return from the function was zero, implying that there were  
205     other matches that did not fit. The correct "exactly full" value is now  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
206     returned.      ovector, the return from the function was zero, implying that there were
207        other matches that did not fit. The correct "exactly full" value is now
208  6. If a subpattern that was called recursively or as a subroutine contained      returned.
209     (*PRUNE) or any other control that caused it to give a non-standard return,  
210     invalid errors such as "Error -26 (nested recursion at the same subject  6.  If a subpattern that was called recursively or as a subroutine contained
211     position)" or even infinite loops could occur.      (*PRUNE) or any other control that caused it to give a non-standard return,
212        invalid errors such as "Error -26 (nested recursion at the same subject
213  7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped      position)" or even infinite loops could occur.
214     computing the minimum length on reaching *ACCEPT, and so ended up with the  
215     wrong value of 1 rather than 0. Further investigation indicates that  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
216     computing a minimum subject length in the presence of *ACCEPT is difficult      computing the minimum length on reaching *ACCEPT, and so ended up with the
217     (think back references, subroutine calls), and so I have changed the code so      wrong value of 1 rather than 0. Further investigation indicates that
218     that no minimum is registered for a pattern that contains *ACCEPT.      computing a minimum subject length in the presence of *ACCEPT is difficult
219        (think back references, subroutine calls), and so I have changed the code
220  8. If (*THEN) was present in the first (true) branch of a conditional group,      so that no minimum is registered for a pattern that contains *ACCEPT.
221     it was not handled as intended.  
222    8.  If (*THEN) was present in the first (true) branch of a conditional group,
223        it was not handled as intended. [But see 16 below.]
224    
225    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
226        Sheri Pierce.
227    
228    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
229        the first byte in a match must be "a".
230    
231    11. Change 17 for 8.13 increased the recursion depth for patterns like
232        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
233        pattern contains any instances of (*THEN). If it does not, the old
234        optimizations are restored. It would be nice to do this on a per-group
235        basis, but at the moment that is not feasible.
236    
237    12. In some environments, the output of pcretest -C is CRLF terminated. This
238        broke RunTest's code that checks for the link size. A single white space
239        character after the value is now allowed for.
240    
241    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
242        For "fr", it uses the Windows-specific input and output files.
243    
244    14. If (*THEN) appeared in a group that was called recursively or as a
245        subroutine, it did not work as intended. [But see next item.]
246    
247    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
248        pattern fragments (but not containing any | characters). If A and B are
249        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
250        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
251        D. In other words, Perl considers parentheses that do not contain any |
252        characters to be part of a surrounding alternative, whereas PCRE was
253        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
254        differently. PCRE now behaves in the same way as Perl, except in the case
255        of subroutine/recursion calls such as (?1) which have in any case always
256        been different (but PCRE had them first :-).
257    
258    16. Related to 15 above: Perl does not treat the | in a conditional group as
259        creating alternatives. Such a group is treated in the same way as an
260        ordinary group without any | characters when processing (*THEN). PCRE has
261        been changed to match Perl's behaviour.
262    
263    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
264        RunGrepTest script failed.
265    
266    18. Change 22 for version 13 caused atomic groups to use more stack. This is
267        inevitable for groups that contain captures, but it can lead to a lot of
268        stack use in large patterns. The old behaviour has been restored for atomic
269        groups that do not contain any capturing parentheses.
270    
271    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
272        suppress the check for a minimum subject length at run time. (If it was
273        given to pcre_exec() or pcre_dfa_exec() it did work.)
274    
275    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
276        fail to work when decoding hex characters in data strings in EBCDIC
277        environments.
278    
279    21. It appears that in at least one Mac OS environment, the isxdigit() function
280        is implemented as a macro that evaluates to its argument more than once,
281        contravening the C 90 Standard (I haven't checked a later standard). There
282        was an instance in pcretest which caused it to go wrong when processing
283        \x{...} escapes in subject strings. The has been rewritten to avoid using
284        things like p++ in the argument of isxdigit().
285    
286    
287  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
# Line 150  Version 8.13 16-Aug-2011 Line 381  Version 8.13 16-Aug-2011
381      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
382      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
383      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
384      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
385    
386  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
387      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be

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