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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14    
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
23    
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
28    
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
34    
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
38    
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
46    
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
72    
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
77    
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collection of tests with study enabled,
83        and thereby test pcre_study() more easily.
84    
85    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
86        restoration of the capturing data to the outer values was not happening
87        correctly.
88    
89    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
90        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
91        pattern had matched an empty string, and so incorrectly returned a no
92        match.
93    
94    
95    Version 8.12 15-Jan-2011
96    ------------------------
97    
98    1.  Fixed some typos in the markup of the man pages, and wrote a script that
99        checks for such things as part of the documentation building process.
100    
101    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
102        --match-limit and --recursion-limit options (added for 8.11). In
103        particular, this made one of the standard tests fail. (The integer value
104        went into the wrong half of a long int.)
105    
106    3.  If the --colour option was given to pcregrep with -v (invert match), it
107        did strange things, either producing crazy output, or crashing. It should,
108        of course, ignore a request for colour when reporting lines that do not
109        match.
110    
111    4.  Another pcregrep bug caused similar problems if --colour was specified with
112        -M (multiline) and the pattern match finished with a line ending.
113    
114    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
115        matched in multiline mode, the following line was shown as part of the
116        match. This seems wrong, so I have changed it.
117    
118    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
119        the check for further matches in the same line (so they could be coloured)
120        to overrun the end of the current line. If another match was found, it was
121        incorrectly shown (and then shown again when found in the next line).
122    
123    7.  If pcregrep was compiled under Windows, there was a reference to the
124        function pcregrep_exit() before it was defined. I am assuming this was
125        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
126        reported by a user. I've moved the definition above the reference.
127    
128    
129    Version 8.11 10-Dec-2010
130    ------------------------
131    
132    1.  (*THEN) was not working properly if there were untried alternatives prior
133        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
134        backtracked to try for "b" instead of moving to the next alternative branch
135        at the same level (in this case, to look for "c"). The Perl documentation
136        is clear that when (*THEN) is backtracked onto, it goes to the "next
137        alternative in the innermost enclosing group".
138    
139    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
140        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
141        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
142        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
143        (*THEN).
144    
145    3.  If \s appeared in a character class, it removed the VT character from
146        the class, even if it had been included by some previous item, for example
147        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
148        of \s, but is part of the POSIX "space" class.)
149    
150    4.  A partial match never returns an empty string (because you can always
151        match an empty string at the end of the subject); however the checking for
152        an empty string was starting at the "start of match" point. This has been
153        changed to the "earliest inspected character" point, because the returned
154        data for a partial match starts at this character. This means that, for
155        example, /(?<=abc)def/ gives a partial match for the subject "abc"
156        (previously it gave "no match").
157    
158    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
159        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
160        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
161        has an implication that the given string is incomplete (because a partial
162        match is preferred over a full match). For this reason, these items now
163        give a partial match in this situation. [Aside: previously, the one case
164        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
165        match rather than a full match, which was wrong by the old rules, but is
166        now correct.]
167    
168    6.  There was a bug in the handling of #-introduced comments, recognized when
169        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
170        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
171        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
172        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
173        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
174        places in pcre_compile().
175    
176    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
177        comments when looking ahead for named forward references to subpatterns,
178        the only newline sequence it recognized was NL. It now handles newlines
179        according to the set newline convention.
180    
181    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
182        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
183        cater for a lack of strerror(). These oversights have been fixed.
184    
185    9.  Added --match-limit and --recursion-limit to pcregrep.
186    
187    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
188    
189    11. When the -o option was used, pcregrep was setting a return code of 1, even
190        when matches were found, and --line-buffered was not being honoured.
191    
192    12. Added an optional parentheses number to the -o and --only-matching options
193        of pcregrep.
194    
195    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
196        can match an empty string. The code to do it in pcretest and pcredemo
197        needed fixing:
198    
199        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
200            only one byte after an empty string match just before CRLF (this case
201            just got forgotten; "any" and "anycrlf" were OK).
202    
203        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
204            mode when an empty string match preceded an ASCII character followed by
205            a non-ASCII character. (The code for advancing by one character rather
206            than one byte was nonsense.)
207    
208        (c) The pcredemo.c sample program did not have any code at all to handle
209            the cases when CRLF is a valid newline sequence.
210    
211    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
212        as a starting offset was within the subject string. There is now a new
213        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
214        negative or greater than the length of the string. In order to test this,
215        pcretest is extended to allow the setting of negative starting offsets.
216    
217    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
218        starting offset points to the beginning of a UTF-8 character was
219        unnecessarily clumsy. I tidied it up.
220    
221    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
222        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
223    
224    17. Nobody had reported that the --include_dir option, which was added in
225        release 7.7 should have been called --include-dir (hyphen, not underscore)
226        for compatibility with GNU grep. I have changed it to --include-dir, but
227        left --include_dir as an undocumented synonym, and the same for
228        --exclude-dir, though that is not available in GNU grep, at least as of
229        release 2.5.4.
230    
231    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
232        characters from a string of bytes) have been redefined so as not to use
233        loops, in order to improve performance in some environments. At the same
234        time, I abstracted some of the common code into auxiliary macros to save
235        repetition (this should not affect the compiled code).
236    
237    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
238        compile-time error is now given if \c is not followed by an ASCII
239        character, that is, a byte less than 128. (In EBCDIC mode, the code is
240        different, and any byte value is allowed.)
241    
242    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
243        START_OPTIMIZE option, which is now allowed at compile time - but just
244        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
245        to pcregrep and other applications that have no direct access to PCRE
246        options. The new /Y option in pcretest sets this option when calling
247        pcre_compile().
248    
249    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
250        back references. Groups containing recursive back references were forced to
251        be atomic by that change, but in the case of named groups, the amount of
252        memory required was incorrectly computed, leading to "Failed: internal
253        error: code overflow". This has been fixed.
254    
255    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
256        pcretest.c, to avoid build problems in some Borland environments.
257    
258    
259    Version 8.10 25-Jun-2010
260    ------------------------
261    
262    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
263        THEN.
264    
265    2.  (*ACCEPT) was not working when inside an atomic group.
266    
267    3.  Inside a character class, \B is treated as a literal by default, but
268        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
269        causes the error). The code is unchanged, but I tidied the documentation.
270    
271    4.  Inside a character class, PCRE always treated \R and \X as literals,
272        whereas Perl faults them if its -w option is set. I have changed PCRE so
273        that it faults them when PCRE_EXTRA is set.
274    
275    5.  Added support for \N, which always matches any character other than
276        newline. (It is the same as "." when PCRE_DOTALL is not set.)
277    
278    6.  When compiling pcregrep with newer versions of gcc which may have
279        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
280        declared with attribute warn_unused_result" were given. Just casting the
281        result to (void) does not stop the warnings; a more elaborate fudge is
282        needed. I've used a macro to implement this.
283    
284    7.  Minor change to pcretest.c to avoid a compiler warning.
285    
286    8.  Added four artifical Unicode properties to help with an option to make
287        \s etc use properties (see next item). The new properties are: Xan
288        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
289    
290    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
291        use Unicode properties. (*UCP) at the start of a pattern can be used to set
292        this option. Modified pcretest to add /W to test this facility. Added
293        REG_UCP to make it available via the POSIX interface.
294    
295    10. Added --line-buffered to pcregrep.
296    
297    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
298        studied, and the match started with a letter with a code point greater than
299        127 whose first byte was different to the first byte of the other case of
300        the letter, the other case of this starting letter was not recognized
301        (#976).
302    
303    12. If a pattern that was studied started with a repeated Unicode property
304        test, for example, \p{Nd}+, there was the theoretical possibility of
305        setting up an incorrect bitmap of starting bytes, but fortunately it could
306        not have actually happened in practice until change 8 above was made (it
307        added property types that matched character-matching opcodes).
308    
309    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
310        possible starting bytes for non-anchored patterns.
311    
312    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
313        \R, and also a number of cases that involve Unicode properties, both
314        explicit and implicit when PCRE_UCP is set.
315    
316    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
317        input, it could crash or give wrong results if characters with values
318        greater than 0xc0 were present in the subject string. (Detail: it assumed
319        UTF-8 input when processing these items.)
320    
321    16. Added a lot of (int) casts to avoid compiler warnings in systems where
322        size_t is 64-bit (#991).
323    
324    17. Added a check for running out of memory when PCRE is compiled with
325        --disable-stack-for-recursion (#990).
326    
327    18. If the last data line in a file for pcretest does not have a newline on
328        the end, a newline was missing in the output.
329    
330    19. The default pcre_chartables.c file recognizes only ASCII characters (values
331        less than 128) in its various bitmaps. However, there is a facility for
332        generating tables according to the current locale when PCRE is compiled. It
333        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
334        characters, are recognized by isspace() and therefore were getting set in
335        these tables, and indeed these tables seem to approximate to ISO 8859. This
336        caused a problem in UTF-8 mode when pcre_study() was used to create a list
337        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
338        which of course cannot start UTF-8 characters. I have changed the code so
339        that only real ASCII characters (less than 128) and the correct starting
340        bytes for UTF-8 encodings are set for characters greater than 127 when in
341        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
342        altogether.)
343    
344    20. Added the /T option to pcretest so as to be able to run tests with non-
345        standard character tables, thus making it possible to include the tests
346        used for 19 above in the standard set of tests.
347    
348    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
349        reference to a subpattern the other side of a comment that contains an
350        opening parenthesis caused either an internal compiling error, or a
351        reference to the wrong subpattern.
352    
353    
354    Version 8.02 19-Mar-2010
355  ------------------------  ------------------------
356    
357  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.
358    
359  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
360      configured.      configured.
361    
362  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
363      original author of that file, following a query about its status.      original author of that file, following a query about its status.
364    
365  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
366      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.
367    
368    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
369        quantifier applied to a forward-referencing subroutine call, could compile
370        incorrect code or give the error "internal error: previously-checked
371        referenced subpattern not found".
372    
373    6.  Both MS Visual Studio and Symbian OS have problems with initializing
374        variables to point to external functions. For these systems, therefore,
375        pcre_malloc etc. are now initialized to local functions that call the
376        relevant global functions.
377    
378    7.  There were two entries missing in the vectors called coptable and poptable
379        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
380        I've fixed the data, and added a kludgy way of testing at compile time that
381        the lengths are correct (equal to the number of opcodes).
382    
383    8.  Following on from 7, I added a similar kludge to check the length of the
384        eint vector in pcreposix.c.
385    
386    9.  Error texts for pcre_compile() are held as one long string to avoid too
387        much relocation at load time. To find a text, the string is searched,
388        counting zeros. There was no check for running off the end of the string,
389        which could happen if a new error number was added without updating the
390        string.
391    
392    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
393    
394    11. \K was not working if it appeared in an atomic group or in a group that
395        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
396        \K is "not well defined" if used in an assertion. PCRE now accepts it if
397        the assertion is positive, but not if it is negative.
398    
399    12. Change 11 fortuitously reduced the size of the stack frame used in the
400        "match()" function of pcre_exec.c by one pointer. Forthcoming
401        implementation of support for (*MARK) will need an extra pointer on the
402        stack; I have reserved it now, so that the stack frame size does not
403        decrease.
404    
405    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
406        item in branch that calls a recursion is a subroutine call - as in the
407        second branch in the above example - was incorrectly given the compile-
408        time error "recursive call could loop indefinitely" because pcre_compile()
409        was not correctly checking the subroutine for matching a non-empty string.
410    
411    14. The checks for overrunning compiling workspace could trigger after an
412        overrun had occurred. This is a "should never occur" error, but it can be
413        triggered by pathological patterns such as hundreds of nested parentheses.
414        The checks now trigger 100 bytes before the end of the workspace.
415    
416    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
417    
418    
419  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
420  ------------------------  ------------------------

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