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revision 486 by ph10, Tue Jan 5 17:44:57 2010 UTC revision 561 by ph10, Sat Oct 30 18:37:47 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.01 06-Jan-10  Version 8.11 10-Oct-2010
5  ----------------------  ------------------------
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".
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).
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.)
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").
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.]
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().
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.
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.
60    9.  Added --match-limit and --recursion-limit to pcregrep.
63    Version 8.10 25-Jun-2010
64    ------------------------
66    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
67        THEN.
69    2.  (*ACCEPT) was not working when inside an atomic group.
71    3.  Inside a character class, \B is treated as a literal by default, but
72        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
73        causes the error). The code is unchanged, but I tidied the documentation.
75    4.  Inside a character class, PCRE always treated \R and \X as literals,
76        whereas Perl faults them if its -w option is set. I have changed PCRE so
77        that it faults them when PCRE_EXTRA is set.
79    5.  Added support for \N, which always matches any character other than
80        newline. (It is the same as "." when PCRE_DOTALL is not set.)
82    6.  When compiling pcregrep with newer versions of gcc which may have
83        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
84        declared with attribute warn_unused_result" were given. Just casting the
85        result to (void) does not stop the warnings; a more elaborate fudge is
86        needed. I've used a macro to implement this.
88    7.  Minor change to pcretest.c to avoid a compiler warning.
90    8.  Added four artifical Unicode properties to help with an option to make
91        \s etc use properties (see next item). The new properties are: Xan
92        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
94    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
95        use Unicode properties. (*UCP) at the start of a pattern can be used to set
96        this option. Modified pcretest to add /W to test this facility. Added
97        REG_UCP to make it available via the POSIX interface.
99    10. Added --line-buffered to pcregrep.
101    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
102        studied, and the match started with a letter with a code point greater than
103        127 whose first byte was different to the first byte of the other case of
104        the letter, the other case of this starting letter was not recognized
105        (#976).
107    12. If a pattern that was studied started with a repeated Unicode property
108        test, for example, \p{Nd}+, there was the theoretical possibility of
109        setting up an incorrect bitmap of starting bytes, but fortunately it could
110        not have actually happened in practice until change 8 above was made (it
111        added property types that matched character-matching opcodes).
113    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
114        possible starting bytes for non-anchored patterns.
116    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
117        \R, and also a number of cases that involve Unicode properties, both
118        explicit and implicit when PCRE_UCP is set.
120    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
121        input, it could crash or give wrong results if characters with values
122        greater than 0xc0 were present in the subject string. (Detail: it assumed
123        UTF-8 input when processing these items.)
125    16. Added a lot of (int) casts to avoid compiler warnings in systems where
126        size_t is 64-bit (#991).
128    17. Added a check for running out of memory when PCRE is compiled with
129        --disable-stack-for-recursion (#990).
131    18. If the last data line in a file for pcretest does not have a newline on
132        the end, a newline was missing in the output.
134    19. The default pcre_chartables.c file recognizes only ASCII characters (values
135        less than 128) in its various bitmaps. However, there is a facility for
136        generating tables according to the current locale when PCRE is compiled. It
137        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
138        characters, are recognized by isspace() and therefore were getting set in
139        these tables, and indeed these tables seem to approximate to ISO 8859. This
140        caused a problem in UTF-8 mode when pcre_study() was used to create a list
141        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
142        which of course cannot start UTF-8 characters. I have changed the code so
143        that only real ASCII characters (less than 128) and the correct starting
144        bytes for UTF-8 encodings are set for characters greater than 127 when in
145        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
146        altogether.)
148    20. Added the /T option to pcretest so as to be able to run tests with non-
149        standard character tables, thus making it possible to include the tests
150        used for 19 above in the standard set of tests.
152    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
153        reference to a subpattern the other side of a comment that contains an
154        opening parenthesis caused either an internal compiling error, or a
155        reference to the wrong subpattern.
158    Version 8.02 19-Mar-2010
159    ------------------------
161    1.  The Unicode data tables have been updated to Unicode 5.2.0.
163    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
164        configured.
166    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
167        original author of that file, following a query about its status.
169    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
170        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
172    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
173        quantifier applied to a forward-referencing subroutine call, could compile
174        incorrect code or give the error "internal error: previously-checked
175        referenced subpattern not found".
177    6.  Both MS Visual Studio and Symbian OS have problems with initializing
178        variables to point to external functions. For these systems, therefore,
179        pcre_malloc etc. are now initialized to local functions that call the
180        relevant global functions.
182    7.  There were two entries missing in the vectors called coptable and poptable
183        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
184        I've fixed the data, and added a kludgy way of testing at compile time that
185        the lengths are correct (equal to the number of opcodes).
187    8.  Following on from 7, I added a similar kludge to check the length of the
188        eint vector in pcreposix.c.
190    9.  Error texts for pcre_compile() are held as one long string to avoid too
191        much relocation at load time. To find a text, the string is searched,
192        counting zeros. There was no check for running off the end of the string,
193        which could happen if a new error number was added without updating the
194        string.
196    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
198    11. \K was not working if it appeared in an atomic group or in a group that
199        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
200        \K is "not well defined" if used in an assertion. PCRE now accepts it if
201        the assertion is positive, but not if it is negative.
203    12. Change 11 fortuitously reduced the size of the stack frame used in the
204        "match()" function of pcre_exec.c by one pointer. Forthcoming
205        implementation of support for (*MARK) will need an extra pointer on the
206        stack; I have reserved it now, so that the stack frame size does not
207        decrease.
209    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
210        item in branch that calls a recursion is a subroutine call - as in the
211        second branch in the above example - was incorrectly given the compile-
212        time error "recursive call could loop indefinitely" because pcre_compile()
213        was not correctly checking the subroutine for matching a non-empty string.
215    14. The checks for overrunning compiling workspace could trigger after an
216        overrun had occurred. This is a "should never occur" error, but it can be
217        triggered by pathological patterns such as hundreds of nested parentheses.
218        The checks now trigger 100 bytes before the end of the workspace.
220    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
223    Version 8.01 19-Jan-2010
224    ------------------------
226  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  If a pattern contained a conditional subpattern with only one branch (in
227      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
228      computed the wrong minimum data length (which is of course zero for such      computed the wrong minimum data length (which is of course zero for such
229      subpatterns).      subpatterns). This could cause incorrect "no match" results.
231  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
232      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
# Line 61  Version 8.01 06-Jan-10 Line 280  Version 8.01 06-Jan-10
280      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
282        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
283          under Win32.            under Win32.
284        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
285          therefore missing the function definition.            therefore missing the function definition.
286        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
287        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
288        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
# Line 113  Version 8.01 06-Jan-10 Line 332  Version 8.01 06-Jan-10
332      equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for      equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
333      instance, but it only takes 2 args instead of 3!"      instance, but it only takes 2 args instead of 3!"
335    18. A subtle bug concerned with back references has been fixed by a change of
336        specification, with a corresponding code fix. A pattern such as
337        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
338        refers, was giving matches when it shouldn't. For example, xa=xaaa would
339        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
340        same bug. Such groups have to be quantified to be useful, or contained
341        inside another quantified group. (If there's no repetition, the reference
342        can never match.) The problem arises because, having left the group and
343        moved on to the rest of the pattern, a later failure that backtracks into
344        the group uses the captured value from the final iteration of the group
345        rather than the correct earlier one. I have fixed this in PCRE by forcing
346        any group that contains a reference to itself to be an atomic group; that
347        is, there cannot be any backtracking into it once it has completed. This is
348        similar to recursive and subroutine calls.
351  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09
352  ----------------------  ----------------------

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