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revision 512 by ph10, Tue Mar 30 11:11:52 2010 UTC revision 580 by ph10, Fri Nov 26 11:16:43 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.03 26-Mar-2010  Version 8.11 24-Nov-2010
5    ------------------------
6    
7    1.  (*THEN) was not working properly if there were untried alternatives prior
8        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9        backtracked to try for "b" instead of moving to the next alternative branch
10        at the same level (in this case, to look for "c"). The Perl documentation
11        is clear that when (*THEN) is backtracked onto, it goes to the "next
12        alternative in the innermost enclosing group".
13    
14    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
16        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18        (*THEN).
19    
20    3.  If \s appeared in a character class, it removed the VT character from
21        the class, even if it had been included by some previous item, for example
22        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23        of \s, but is part of the POSIX "space" class.)
24    
25    4.  A partial match never returns an empty string (because you can always
26        match an empty string at the end of the subject); however the checking for
27        an empty string was starting at the "start of match" point. This has been
28        changed to the "earliest inspected character" point, because the returned
29        data for a partial match starts at this character. This means that, for
30        example, /(?<=abc)def/ gives a partial match for the subject "abc"
31        (previously it gave "no match").
32    
33    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36        has an implication that the given string is incomplete (because a partial
37        match is preferred over a full match). For this reason, these items now
38        give a partial match in this situation. [Aside: previously, the one case
39        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40        match rather than a full match, which was wrong by the old rules, but is
41        now correct.]
42    
43    6.  There was a bug in the handling of #-introduced comments, recognized when
44        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49        places in pcre_compile().
50    
51    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
52        comments when looking ahead for named forward references to subpatterns,
53        the only newline sequence it recognized was NL. It now handles newlines
54        according to the set newline convention.
55    
56    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58        cater for a lack of strerror(). These oversights have been fixed.
59    
60    9.  Added --match-limit and --recursion-limit to pcregrep.
61    
62    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63    
64    11. When the -o option was used, pcregrep was setting a return code of 1, even
65        when matches were found, and --line-buffered was not being honoured.
66    
67    12. Added an optional parentheses number to the -o and --only-matching options
68        of pcregrep.
69    
70    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
71        can match an empty string. The code to do it in pcretest and pcredemo
72        needed fixing:
73    
74        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
75            only one byte after an empty string match just before CRLF (this case
76            just got forgotten; "any" and "anycrlf" were OK).
77    
78        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
79            mode when an empty string match preceded an ASCII character followed by
80            a non-ASCII character. (The code for advancing by one character rather
81            than one byte was nonsense.)
82    
83        (c) The pcredemo.c sample program did not have any code at all to handle
84            the cases when CRLF is a valid newline sequence.
85    
86    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
87        as a starting offset was within the subject string. There is now a new
88        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
89        negative or greater than the length of the string. In order to test this,
90        pcretest is extended to allow the setting of negative starting offsets.
91    
92    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
93        starting offset points to the beginning of a UTF-8 character was
94        unnecessarily clumsy. I tidied it up.
95    
96    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
97        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
98    
99    17. Nobody had reported that the --include_dir option, which was added in
100        release 7.7 should have been called --include-dir (hyphen, not underscore)
101        for compatibility with GNU grep. I have changed it to --include-dir, but
102        left --include_dir as an undocumented synonym, and the same for
103        --exclude-dir, though that is not available in GNU grep, at least as of
104        release 2.5.4.
105    
106    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
107        characters from a string of bytes) have been redefined so as not to use
108        loops, in order to improve performance in some environments. At the same
109        time, I abstracted some of the common code into auxiliary macros to save
110        repetition (this should not affect the compiled code).
111    
112    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
113        compile-time error is now given if \c is not followed by an ASCII
114        character, that is, a byte less than 128. (In EBCDIC mode, the code is
115        different, and any byte value is allowed.)
116    
117    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
118        START_OPTIMIZE option, which is now allowed at compile time - but just
119        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
120        to pcregrep and other applications that have no direct access to PCRE
121        options. The new /Y option in pcretest sets this option when calling
122        pcre_compile().
123    
124    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
125        back references. Groups containing recursive back references were forced to
126        be atomic by that change, but in the case of named groups, the amount of
127        memory required was incorrectly computed, leading to "Failed: internal
128        error: code overflow". This has been fixed.
129    
130    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
131        pcretest.c, to avoid build problems in some Borland environments.
132    
133    
134    Version 8.10 25-Jun-2010
135  ------------------------  ------------------------
136    
137  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 9  Version 8.03 26-Mar-2010 Line 139  Version 8.03 26-Mar-2010
139    
140  2.  (*ACCEPT) was not working when inside an atomic group.  2.  (*ACCEPT) was not working when inside an atomic group.
141    
142    3.  Inside a character class, \B is treated as a literal by default, but
143        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
144        causes the error). The code is unchanged, but I tidied the documentation.
145    
146    4.  Inside a character class, PCRE always treated \R and \X as literals,
147        whereas Perl faults them if its -w option is set. I have changed PCRE so
148        that it faults them when PCRE_EXTRA is set.
149    
150    5.  Added support for \N, which always matches any character other than
151        newline. (It is the same as "." when PCRE_DOTALL is not set.)
152    
153    6.  When compiling pcregrep with newer versions of gcc which may have
154        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
155        declared with attribute warn_unused_result" were given. Just casting the
156        result to (void) does not stop the warnings; a more elaborate fudge is
157        needed. I've used a macro to implement this.
158    
159    7.  Minor change to pcretest.c to avoid a compiler warning.
160    
161    8.  Added four artifical Unicode properties to help with an option to make
162        \s etc use properties (see next item). The new properties are: Xan
163        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
164    
165    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
166        use Unicode properties. (*UCP) at the start of a pattern can be used to set
167        this option. Modified pcretest to add /W to test this facility. Added
168        REG_UCP to make it available via the POSIX interface.
169    
170    10. Added --line-buffered to pcregrep.
171    
172    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
173        studied, and the match started with a letter with a code point greater than
174        127 whose first byte was different to the first byte of the other case of
175        the letter, the other case of this starting letter was not recognized
176        (#976).
177    
178    12. If a pattern that was studied started with a repeated Unicode property
179        test, for example, \p{Nd}+, there was the theoretical possibility of
180        setting up an incorrect bitmap of starting bytes, but fortunately it could
181        not have actually happened in practice until change 8 above was made (it
182        added property types that matched character-matching opcodes).
183    
184    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
185        possible starting bytes for non-anchored patterns.
186    
187    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
188        \R, and also a number of cases that involve Unicode properties, both
189        explicit and implicit when PCRE_UCP is set.
190    
191    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
192        input, it could crash or give wrong results if characters with values
193        greater than 0xc0 were present in the subject string. (Detail: it assumed
194        UTF-8 input when processing these items.)
195    
196    16. Added a lot of (int) casts to avoid compiler warnings in systems where
197        size_t is 64-bit (#991).
198    
199    17. Added a check for running out of memory when PCRE is compiled with
200        --disable-stack-for-recursion (#990).
201    
202    18. If the last data line in a file for pcretest does not have a newline on
203        the end, a newline was missing in the output.
204    
205    19. The default pcre_chartables.c file recognizes only ASCII characters (values
206        less than 128) in its various bitmaps. However, there is a facility for
207        generating tables according to the current locale when PCRE is compiled. It
208        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
209        characters, are recognized by isspace() and therefore were getting set in
210        these tables, and indeed these tables seem to approximate to ISO 8859. This
211        caused a problem in UTF-8 mode when pcre_study() was used to create a list
212        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
213        which of course cannot start UTF-8 characters. I have changed the code so
214        that only real ASCII characters (less than 128) and the correct starting
215        bytes for UTF-8 encodings are set for characters greater than 127 when in
216        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
217        altogether.)
218    
219    20. Added the /T option to pcretest so as to be able to run tests with non-
220        standard character tables, thus making it possible to include the tests
221        used for 19 above in the standard set of tests.
222    
223    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
224        reference to a subpattern the other side of a comment that contains an
225        opening parenthesis caused either an internal compiling error, or a
226        reference to the wrong subpattern.
227    
228    
229  Version 8.02 19-Mar-2010  Version 8.02 19-Mar-2010
230  ------------------------  ------------------------

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