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revision 354 by ph10, Mon Jul 7 16:30:33 2008 UTC revision 462 by ph10, Sat Oct 17 19:55:02 2009 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.0 02 Jul-08  Version 8.00 05-Oct-09
5    ----------------------
6    
7    1.  The table for translating pcre_compile() error codes into POSIX error codes
8        was out-of-date, and there was no check on the pcre_compile() error code
9        being within the table. This could lead to an OK return being given in
10        error.
11    
12    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
13        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14        in a Windows environment.
15    
16    3.  The pcregrep --count option prints the count for each file even when it is
17        zero, as does GNU grep. However, pcregrep was also printing all files when
18        --files-with-matches was added. Now, when both options are given, it prints
19        counts only for those files that have at least one match. (GNU grep just
20        prints the file name in this circumstance, but including the count seems
21        more useful - otherwise, why use --count?) Also ensured that the
22        combination -clh just lists non-zero counts, with no names.
23    
24    4.  The long form of the pcregrep -F option was incorrectly implemented as
25        --fixed_strings instead of --fixed-strings. This is an incompatible change,
26        but it seems right to fix it, and I didn't think it was worth preserving
27        the old behaviour.
28    
29    5.  The command line items --regex=pattern and --regexp=pattern were not
30        recognized by pcregrep, which required --regex pattern or --regexp pattern
31        (with a space rather than an '='). The man page documented the '=' forms,
32        which are compatible with GNU grep; these now work.
33    
34    6.  No libpcreposix.pc file was created for pkg-config; there was just
35        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
36    
37    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38        when UCP support is not needed, by modifying the Python script that
39        generates it from Unicode data files. This should not matter if the module
40        is correctly used as a library, but I received one complaint about 50K of
41        unwanted data. My guess is that the person linked everything into his
42        program rather than using a library. Anyway, it does no harm.
43    
44    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45        was a minimum greater than 1 for a wide character in a possessive
46        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48        character. Chaos in the form of incorrect output or a compiling loop could
49        result.
50    
51    9.  The restrictions on what a pattern can contain when partial matching is
52        requested for pcre_exec() have been removed. All patterns can now be
53        partially matched by this function. In addition, if there are at least two
54        slots in the offset vector, the offset of the earliest inspected character
55        for the match and the offset of the end of the subject are set in them when
56        PCRE_ERROR_PARTIAL is returned.
57    
58    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59        synonymous with PCRE_PARTIAL, for backwards compatibility, and
60        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61        and may be more useful for multi-segment matching.
62    
63    11. Partial matching with pcre_exec() is now more intuitive. A partial match
64        used to be given if ever the end of the subject was reached; now it is
65        given only if matching could not proceed because another character was
66        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
67        string "Z", which now yields "no match" instead of "partial match". In the
68        case of pcre_dfa_exec(), "no match" is given if every matching path for the
69        final character ended with (*FAIL).
70    
71    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
72        if the pattern had a "must contain" character that was already found in the
73        earlier partial match, unless partial matching was again requested. For
74        example, with the pattern /dog.(body)?/, the "must contain" character is
75        "g". If the first part-match was for the string "dog", restarting with
76        "sbody" failed. This bug has been fixed.
77    
78    13. The string returned by pcre_dfa_exec() after a partial match has been
79        changed so that it starts at the first inspected character rather than the
80        first character of the match. This makes a difference only if the pattern
81        starts with a lookbehind assertion or \b or \B (\K is not supported by
82        pcre_dfa_exec()). It's an incompatible change, but it makes the two
83        matching functions compatible, and I think it's the right thing to do.
84    
85    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
86        so that the demonstration program is easily available in environments where
87        PCRE has not been installed from source.
88    
89    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
90        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
91        library.
92    
93    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
94        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
95        is not the first non-POSIX option to be added. Clearly some people find
96        these options useful.
97    
98    17. If a caller to the POSIX matching function regexec() passes a non-zero
99        value for nmatch with a NULL value for pmatch, the value of
100        nmatch is forced to zero.
101    
102    18. RunGrepTest did not have a test for the availability of the -u option of
103        the diff command, as RunTest does. It now checks in the same way as
104        RunTest, and also checks for the -b option.
105    
106    19. If an odd number of negated classes containing just a single character
107        interposed, within parentheses, between a forward reference to a named
108        subpattern and the definition of the subpattern, compilation crashed with
109        an internal error, complaining that it could not find the referenced
110        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
111        [The bug was that it was starting one character too far in when skipping
112        over the character class, thus treating the ] as data rather than
113        terminating the class. This meant it could skip too much.]
114    
115    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
116        /g option in pcretest when the pattern contains \K, which makes it possible
117        to have an empty string match not at the start, even when the pattern is
118        anchored. Updated pcretest and pcredemo to use this option.
119    
120    21. If the maximum number of capturing subpatterns in a recursion was greater
121        than the maximum at the outer level, the higher number was returned, but
122        with unset values at the outer level. The correct (outer level) value is
123        now given.
124    
125    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
126        PCRE did not set those parentheses (unlike Perl). I have now found a way to
127        make it do so. The string so far is captured, making this feature
128        compatible with Perl.
129    
130    23. The tests have been re-organized, adding tests 11 and 12, to make it
131        possible to check the Perl 5.10 features against Perl 5.10.
132    
133    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
134        pattern matches a fixed length string. PCRE did not allow this; now it
135        does. Neither allows recursion.
136    
137    25. I finally figured out how to implement a request to provide the minimum
138        length of subject string that was needed in order to match a given pattern.
139        (It was back references and recursion that I had previously got hung up
140        on.) This code has now been added to pcre_study(); it finds a lower bound
141        to the length of subject needed. It is not necessarily the greatest lower
142        bound, but using it to avoid searching strings that are too short does give
143        some useful speed-ups. The value is available to calling programs via
144        pcre_fullinfo().
145    
146    26. While implementing 25, I discovered to my embarrassment that pcretest had
147        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
148        study optimizations had never been tested with that matching function.
149        Oops. What is worse, even when it was passed study data, there was a bug in
150        pcre_dfa_exec() that meant it never actually used it. Double oops. There
151        were also very few tests of studied patterns with pcre_dfa_exec().
152    
153    27. If (?| is used to create subpatterns with duplicate numbers, they are now
154        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
155        on the other side of the coin, they are no longer allowed to have different
156        names, because these cannot be distinguished in PCRE, and this has caused
157        confusion. (This is a difference from Perl.)
158    
159    28. When duplicate subpattern names are present (necessarily with different
160        numbers, as required by 27 above), and a test is made by name in a
161        conditional pattern, either for a subpattern having been matched, or for
162        recursion in such a pattern, all the associated numbered subpatterns are
163        tested, and the overall condition is true if the condition is true for any
164        one of them. This is the way Perl works, and is also more like the way
165        testing by number works.
166    
167    
168    Version 7.9 11-Apr-09
169    ---------------------
170    
171    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
172        (pcretest), all targets were linked against these libraries. This included
173        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
174        libraries. This caused unwanted dependencies to be created. This problem
175        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
176        pcretest is linked with readline.
177    
178    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
179        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
180        moved outside it again, because FALSE and TRUE are already defined in AIX,
181        but BOOL is not.
182    
183    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
184        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
185    
186    4.  The pcregrep documentation said spaces were inserted as well as colons (or
187        hyphens) following file names and line numbers when outputting matching
188        lines. This is not true; no spaces are inserted. I have also clarified the
189        wording for the --colour (or --color) option.
190    
191    5.  In pcregrep, when --colour was used with -o, the list of matching strings
192        was not coloured; this is different to GNU grep, so I have changed it to be
193        the same.
194    
195    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
196        each matching line was coloured. Now it goes on to look for further matches
197        of any of the test patterns, which is the same behaviour as GNU grep.
198    
199    7.  A pattern that could match an empty string could cause pcregrep to loop; it
200        doesn't make sense to accept an empty string match in pcregrep, so I have
201        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
202        seems to be how GNU grep behaves.
203    
204    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
205        start or after a newline", because the conditional assertion was not being
206        correctly handled. The rule now is that both the assertion and what follows
207        in the first alternative must satisfy the test.
208    
209    9.  If auto-callout was enabled in a pattern with a conditional group whose
210        condition was an assertion, PCRE could crash during matching, both with
211        pcre_exec() and pcre_dfa_exec().
212    
213    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
214        used for matching.
215    
216    11. Unicode property support in character classes was not working for
217        characters (bytes) greater than 127 when not in UTF-8 mode.
218    
219    12. Added the -M command line option to pcretest.
220    
221    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
222    
223    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
224    
225    16. Added comments and documentation about mis-use of no_arg in the C++
226        wrapper.
227    
228    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
229        from Martin Jerabek that uses macro names for all relevant character and
230        string constants.
231    
232    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
233        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
234        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
235        these, but not everybody uses configure.
236    
237    19. A conditional group that had only one branch was not being correctly
238        recognized as an item that could match an empty string. This meant that an
239        enclosing group might also not be so recognized, causing infinite looping
240        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
241        with the subject "ab", where knowledge that the repeated group can match
242        nothing is needed in order to break the loop.
243    
244    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
245        exec(), but without supplying a callout function, matching went wrong.
246    
247    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
248        leak if the size of the offset vector was greater than 30. When the vector
249        is smaller, the saved offsets during recursion go onto a local stack
250        vector, but for larger vectors malloc() is used. It was failing to free
251        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
252        error, in fact).
253    
254    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
255        heapframe that is used only when UTF-8 support is enabled. This caused no
256        problem, but was untidy.
257    
258    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
259        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
260        included within another project.
261    
262    24. Steven Van Ingelgem's patches to add more options to the CMake support,
263        slightly modified by me:
264    
265          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
266              not building pcregrep.
267    
268          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
269              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
270    
271    25. Forward references, both numeric and by name, in patterns that made use of
272        duplicate group numbers, could behave incorrectly or give incorrect errors,
273        because when scanning forward to find the reference group, PCRE was not
274        taking into account the duplicate group numbers. A pattern such as
275        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
276    
277    26. Changed a few more instances of "const unsigned char *" to USPTR, making
278        the feature of a custom pointer more persuasive (as requested by a user).
279    
280    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
281        pcretest.c, inside #ifndefs, because it seems they are sometimes already
282        pre-defined.
283    
284    28. Added support for (*UTF8) at the start of a pattern.
285    
286    29. Arrange for flags added by the "release type" setting in CMake to be shown
287        in the configuration summary.
288    
289    
290    Version 7.8 05-Sep-08
291  ---------------------  ---------------------
292    
293  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
# Line 13  Version 8.0 02 Jul-08 Line 299  Version 8.0 02 Jul-08
299    
300  2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more  2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
301      scripts.      scripts.
302    
303  3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained  3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
304      a group with a zero qualifier. The result of the study could be incorrect,      a group with a zero qualifier. The result of the study could be incorrect,
305      or the function might crash, depending on the pattern.      or the function might crash, depending on the pattern.
306    
307  4.  Caseless matching was not working for non-ASCII characters in back  4.  Caseless matching was not working for non-ASCII characters in back
308      references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.      references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
309      It now works when Unicode Property Support is available.      It now works when Unicode Property Support is available.
310    
311    5.  In pcretest, an escape such as \x{de} in the data was always generating
312        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
313        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
314        truncation.
315    
316    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
317    
318    7.  Added two (int) casts to pcregrep when printing the difference of two
319        pointers, in case they are 64-bit values.
320    
321    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
322        test 2 if it fails.
323    
324    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
325        and a #define of that name to empty if it is not externally set. This is to
326        allow users of MSVC to set it if necessary.
327    
328    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
329        the convenience functions in the pcre_get.c source file.
330    
331    11. An option change at the start of a pattern that had top-level alternatives
332        could cause overwriting and/or a crash. This command provoked a crash in
333        some environments:
334    
335          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
336    
337        This potential security problem was recorded as CVE-2008-2371.
338    
339    12. For a pattern where the match had to start at the beginning or immediately
340        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
341        pcre_dfa_exec() could read past the end of the passed subject if there was
342        no match. To help with detecting such bugs (e.g. with valgrind), I modified
343        pcretest so that it places the subject at the end of its malloc-ed buffer.
344    
345    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
346        exec() might read past the end of the data buffer in UTF-8 mode.
347    
348    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
349        the data contained the byte 0x85 as part of a UTF-8 character within its
350        first line. This applied both to normal and DFA matching.
351    
352    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
353        /^[^d]*?$/8 failed to match "abc".
354    
355    16. Added a missing copyright notice to pcrecpp_internal.h.
356    
357    17. Make it more clear in the documentation that values returned from
358        pcre_exec() in ovector are byte offsets, not character counts.
359    
360    18. Tidied a few places to stop certain compilers from issuing warnings.
361    
362    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
363        supplied by Stefan Weber. I made a further small update for 7.8 because
364        there is a change of source arrangements: the pcre_searchfuncs.c module is
365        replaced by pcre_ucd.c.
366    
367    
368  Version 7.7 07-May-08  Version 7.7 07-May-08

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