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revision 497 by ph10, Wed Mar 3 12:01:00 2010 UTC revision 571 by ph10, Tue Nov 16 17:51:37 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.11 10-Oct-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.
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    
107    Version 8.10 25-Jun-2010
108    ------------------------
109    
110    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
111        THEN.
112    
113    2.  (*ACCEPT) was not working when inside an atomic group.
114    
115    3.  Inside a character class, \B is treated as a literal by default, but
116        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
117        causes the error). The code is unchanged, but I tidied the documentation.
118    
119    4.  Inside a character class, PCRE always treated \R and \X as literals,
120        whereas Perl faults them if its -w option is set. I have changed PCRE so
121        that it faults them when PCRE_EXTRA is set.
122    
123    5.  Added support for \N, which always matches any character other than
124        newline. (It is the same as "." when PCRE_DOTALL is not set.)
125    
126    6.  When compiling pcregrep with newer versions of gcc which may have
127        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
128        declared with attribute warn_unused_result" were given. Just casting the
129        result to (void) does not stop the warnings; a more elaborate fudge is
130        needed. I've used a macro to implement this.
131    
132    7.  Minor change to pcretest.c to avoid a compiler warning.
133    
134    8.  Added four artifical Unicode properties to help with an option to make
135        \s etc use properties (see next item). The new properties are: Xan
136        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
137    
138    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
139        use Unicode properties. (*UCP) at the start of a pattern can be used to set
140        this option. Modified pcretest to add /W to test this facility. Added
141        REG_UCP to make it available via the POSIX interface.
142    
143    10. Added --line-buffered to pcregrep.
144    
145    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
146        studied, and the match started with a letter with a code point greater than
147        127 whose first byte was different to the first byte of the other case of
148        the letter, the other case of this starting letter was not recognized
149        (#976).
150    
151    12. If a pattern that was studied started with a repeated Unicode property
152        test, for example, \p{Nd}+, there was the theoretical possibility of
153        setting up an incorrect bitmap of starting bytes, but fortunately it could
154        not have actually happened in practice until change 8 above was made (it
155        added property types that matched character-matching opcodes).
156    
157    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
158        possible starting bytes for non-anchored patterns.
159    
160    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
161        \R, and also a number of cases that involve Unicode properties, both
162        explicit and implicit when PCRE_UCP is set.
163    
164    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
165        input, it could crash or give wrong results if characters with values
166        greater than 0xc0 were present in the subject string. (Detail: it assumed
167        UTF-8 input when processing these items.)
168    
169    16. Added a lot of (int) casts to avoid compiler warnings in systems where
170        size_t is 64-bit (#991).
171    
172    17. Added a check for running out of memory when PCRE is compiled with
173        --disable-stack-for-recursion (#990).
174    
175    18. If the last data line in a file for pcretest does not have a newline on
176        the end, a newline was missing in the output.
177    
178    19. The default pcre_chartables.c file recognizes only ASCII characters (values
179        less than 128) in its various bitmaps. However, there is a facility for
180        generating tables according to the current locale when PCRE is compiled. It
181        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
182        characters, are recognized by isspace() and therefore were getting set in
183        these tables, and indeed these tables seem to approximate to ISO 8859. This
184        caused a problem in UTF-8 mode when pcre_study() was used to create a list
185        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
186        which of course cannot start UTF-8 characters. I have changed the code so
187        that only real ASCII characters (less than 128) and the correct starting
188        bytes for UTF-8 encodings are set for characters greater than 127 when in
189        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
190        altogether.)
191    
192    20. Added the /T option to pcretest so as to be able to run tests with non-
193        standard character tables, thus making it possible to include the tests
194        used for 19 above in the standard set of tests.
195    
196    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
197        reference to a subpattern the other side of a comment that contains an
198        opening parenthesis caused either an internal compiling error, or a
199        reference to the wrong subpattern.
200    
201    
202    Version 8.02 19-Mar-2010
203  ------------------------  ------------------------
204    
205  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
206    
207  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
208      configured.      configured.
209    
210  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
211      original author of that file, following a query about its status.      original author of that file, following a query about its status.
212    
213  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
214      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
215    
216  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
217      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
218      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
219      referenced subpattern not found".      referenced subpattern not found".
220    
221  6.  Both MS Visual Studio and Symbian OS have problems with initializing  6.  Both MS Visual Studio and Symbian OS have problems with initializing
222      variables to point to external functions. For these systems, therefore,      variables to point to external functions. For these systems, therefore,
223      pcre_malloc etc. are now initialized to local functions that call the      pcre_malloc etc. are now initialized to local functions that call the
224      relevant global functions.      relevant global functions.
225    
226    7.  There were two entries missing in the vectors called coptable and poptable
227        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
228        I've fixed the data, and added a kludgy way of testing at compile time that
229        the lengths are correct (equal to the number of opcodes).
230    
231    8.  Following on from 7, I added a similar kludge to check the length of the
232        eint vector in pcreposix.c.
233    
234    9.  Error texts for pcre_compile() are held as one long string to avoid too
235        much relocation at load time. To find a text, the string is searched,
236        counting zeros. There was no check for running off the end of the string,
237        which could happen if a new error number was added without updating the
238        string.
239    
240    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
241    
242    11. \K was not working if it appeared in an atomic group or in a group that
243        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
244        \K is "not well defined" if used in an assertion. PCRE now accepts it if
245        the assertion is positive, but not if it is negative.
246    
247    12. Change 11 fortuitously reduced the size of the stack frame used in the
248        "match()" function of pcre_exec.c by one pointer. Forthcoming
249        implementation of support for (*MARK) will need an extra pointer on the
250        stack; I have reserved it now, so that the stack frame size does not
251        decrease.
252    
253    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
254        item in branch that calls a recursion is a subroutine call - as in the
255        second branch in the above example - was incorrectly given the compile-
256        time error "recursive call could loop indefinitely" because pcre_compile()
257        was not correctly checking the subroutine for matching a non-empty string.
258    
259    14. The checks for overrunning compiling workspace could trigger after an
260        overrun had occurred. This is a "should never occur" error, but it can be
261        triggered by pathological patterns such as hundreds of nested parentheses.
262        The checks now trigger 100 bytes before the end of the workspace.
263    
264    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
265    
266    
267  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
268  ------------------------  ------------------------

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