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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-08  Version 8.00 ??-???-??
5    ----------------------
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8        was out-of-date, and there was no check on the pcre_compile() error code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.
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.
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.
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.
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.
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.
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.
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.
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.
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, especially with
62        pcre_exec().
64    11. Partial matching with pcre_exec() is now more intuitive. A partial match
65        used to be given if ever the end of the subject was reached; now it is
66        given only if matching could not proceed because another character was
67        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68        string "Z", which now yields "no match" instead of "partial match". In the
69        case of pcre_dfa_exec(), "no match" is given if every matching path for the
70        final character ended with (*FAIL).
72    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73        if the pattern had a "must contain" character that was already found in the
74        earlier partial match, unless partial matching was again requested. For
75        example, with the pattern /dog.(body)?/, the "must contain" character is
76        "g". If the first part-match was for the string "dog", restarting with
77        "sbody" failed. This bug has been fixed.
79    13. The string returned by pcre_dfa_exec() after a partial match has been
80        changed so that it starts at the first inspected character rather than the
81        first character of the match. This makes a difference only if the pattern
82        starts with a lookbehind assertion or \b or \B (\K is not supported by
83        pcre_dfa_exec()). It's an incompatible change, but it makes the two
84        matching functions compatible, and I think it's the right thing to do.
86    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87        so that the demonstration program is easily available in environments where
88        PCRE has not been installed from source.
90    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92        library.
94    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96        is not the first non-POSIX option to be added. Clearly some people find
97        these options useful.
99    17. If a caller to the POSIX matching function regexec() passes a non-zero
100        value for nmatch with a NULL value for pmatch, the value of
101        nmatch is forced to zero.
103    18. RunGrepTest did not have a test for the availability of the -u option of
104        the diff command, as RunTest does. It now checks in the same way as
105        RunTest, and also checks for the -b option.
107    19. If an odd number of negated classes containing just a single character
108        interposed, within parentheses, between a forward reference to a named
109        subpattern and the definition of the subpattern, compilation crashed with
110        an internal error, complaining that it could not find the referenced
111        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112        [The bug was that it was starting one character too far in when skipping
113        over the character class, thus treating the ] as data rather than
114        terminating the class. This meant it could skip too much.]
116    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
117        /g option in pcretest when the pattern contains \K, which makes it possible
118        to have an empty string match not at the start, even when the pattern is
119        anchored. Updated pcretest and pcredemo to use this option.
121    21. If the maximum number of capturing subpatterns in a recursion was greater
122        than the maximum at the outer level, the higher number was returned, but
123        with unset values at the outer level. The correct (outer level) value is
124        now given.
126    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
127        PCRE did not set those parentheses (unlike Perl). I have now found a way to
128        make it do so. The string so far is captured, making this feature
129        compatible with Perl.
131    23. The tests have been re-organized, adding tests 11 and 12, to make it
132        possible to check the Perl 5.10 features against Perl 5.10.
134    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
135        pattern matches a fixed length string. PCRE did not allow this; now it
136        does. Neither allows recursion.
138    25. I finally figured out how to implement a request to provide the minimum
139        length of subject string that was needed in order to match a given pattern.
140        (It was back references and recursion that I had previously got hung up
141        on.) This code has now been added to pcre_study(); it finds a lower bound
142        to the length of subject needed. It is not necessarily the greatest lower
143        bound, but using it to avoid searching strings that are too short does give
144        some useful speed-ups. The value is available to calling programs via
145        pcre_fullinfo().
147    26. While implementing 25, I discovered to my embarrassment that pcretest had
148        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
149        study optimizations had never been tested with that matching function.
150        Oops. What is worse, even when it was passed study data, there was a bug in
151        pcre_dfa_exec() that meant it never actually used it. Double oops. There
152        were also very few tests of studied patterns with pcre_dfa_exec().
154    27. If (?| is used to create subpatterns with duplicate numbers, they are now
155        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
156        on the other side of the coin, they are no longer allowed to have different
157        names, because these cannot be distinguished in PCRE, and this has caused
158        confusion. (This is a difference from Perl.)
160    28. When duplicate subpattern names are present (necessarily with different
161        numbers, as required by 27 above), and a test is made by name in a
162        conditional pattern, either for a subpattern having been matched, or for
163        recursion in such a pattern, all the associated numbered subpatterns are
164        tested, and the overall condition is true if the condition is true for any
165        one of them. This is the way Perl works, and is also more like the way
166        testing by number works.
169    Version 7.9 11-Apr-09
170    ---------------------
172    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
173        (pcretest), all targets were linked against these libraries. This included
174        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
175        libraries. This caused unwanted dependencies to be created. This problem
176        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
177        pcretest is linked with readline.
179    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
180        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
181        moved outside it again, because FALSE and TRUE are already defined in AIX,
182        but BOOL is not.
184    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
185        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
187    4.  The pcregrep documentation said spaces were inserted as well as colons (or
188        hyphens) following file names and line numbers when outputting matching
189        lines. This is not true; no spaces are inserted. I have also clarified the
190        wording for the --colour (or --color) option.
192    5.  In pcregrep, when --colour was used with -o, the list of matching strings
193        was not coloured; this is different to GNU grep, so I have changed it to be
194        the same.
196    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
197        each matching line was coloured. Now it goes on to look for further matches
198        of any of the test patterns, which is the same behaviour as GNU grep.
200    7.  A pattern that could match an empty string could cause pcregrep to loop; it
201        doesn't make sense to accept an empty string match in pcregrep, so I have
202        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
203        seems to be how GNU grep behaves.
205    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
206        start or after a newline", because the conditional assertion was not being
207        correctly handled. The rule now is that both the assertion and what follows
208        in the first alternative must satisfy the test.
210    9.  If auto-callout was enabled in a pattern with a conditional group whose
211        condition was an assertion, PCRE could crash during matching, both with
212        pcre_exec() and pcre_dfa_exec().
214    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
215        used for matching.
217    11. Unicode property support in character classes was not working for
218        characters (bytes) greater than 127 when not in UTF-8 mode.
220    12. Added the -M command line option to pcretest.
222    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
224    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
226    16. Added comments and documentation about mis-use of no_arg in the C++
227        wrapper.
229    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
230        from Martin Jerabek that uses macro names for all relevant character and
231        string constants.
233    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
234        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
235        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
236        these, but not everybody uses configure.
238    19. A conditional group that had only one branch was not being correctly
239        recognized as an item that could match an empty string. This meant that an
240        enclosing group might also not be so recognized, causing infinite looping
241        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
242        with the subject "ab", where knowledge that the repeated group can match
243        nothing is needed in order to break the loop.
245    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
246        exec(), but without supplying a callout function, matching went wrong.
248    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
249        leak if the size of the offset vector was greater than 30. When the vector
250        is smaller, the saved offsets during recursion go onto a local stack
251        vector, but for larger vectors malloc() is used. It was failing to free
252        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
253        error, in fact).
255    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
256        heapframe that is used only when UTF-8 support is enabled. This caused no
257        problem, but was untidy.
259    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
260        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
261        included within another project.
263    24. Steven Van Ingelgem's patches to add more options to the CMake support,
264        slightly modified by me:
266          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
267              not building pcregrep.
269          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
270              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
272    25. Forward references, both numeric and by name, in patterns that made use of
273        duplicate group numbers, could behave incorrectly or give incorrect errors,
274        because when scanning forward to find the reference group, PCRE was not
275        taking into account the duplicate group numbers. A pattern such as
276        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
278    26. Changed a few more instances of "const unsigned char *" to USPTR, making
279        the feature of a custom pointer more persuasive (as requested by a user).
281    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
282        pcretest.c, inside #ifndefs, because it seems they are sometimes already
283        pre-defined.
285    28. Added support for (*UTF8) at the start of a pattern.
287    29. Arrange for flags added by the "release type" setting in CMake to be shown
288        in the configuration summary.
291    Version 7.8 05-Sep-08
292  ---------------------  ---------------------
294  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
295      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
296      stage table and inline lookup instead of a function, giving speed ups of 2      stage table and inline lookup instead of a function, giving speed ups of 2
297      to 5 times on some simple patterns that I tested. Permission was given to      to 5 times on some simple patterns that I tested. Permission was given to
298      distribute the MultiStage2.py script that generates the tables (it's not in      distribute the MultiStage2.py script that generates the tables (it's not in
299      the tarball, but is in the Subversion repository).      the tarball, but is in the Subversion repository).
301    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
302        scripts.
304    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
305        a group with a zero qualifier. The result of the study could be incorrect,
306        or the function might crash, depending on the pattern.
308    4.  Caseless matching was not working for non-ASCII characters in back
309        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
310        It now works when Unicode Property Support is available.
312    5.  In pcretest, an escape such as \x{de} in the data was always generating
313        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
314        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
315        truncation.
317    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
319    7.  Added two (int) casts to pcregrep when printing the difference of two
320        pointers, in case they are 64-bit values.
322    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
323        test 2 if it fails.
325    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
326        and a #define of that name to empty if it is not externally set. This is to
327        allow users of MSVC to set it if necessary.
329    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
330        the convenience functions in the pcre_get.c source file.
332    11. An option change at the start of a pattern that had top-level alternatives
333        could cause overwriting and/or a crash. This command provoked a crash in
334        some environments:
336          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
338        This potential security problem was recorded as CVE-2008-2371.
340    12. For a pattern where the match had to start at the beginning or immediately
341        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
342        pcre_dfa_exec() could read past the end of the passed subject if there was
343        no match. To help with detecting such bugs (e.g. with valgrind), I modified
344        pcretest so that it places the subject at the end of its malloc-ed buffer.
346    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
347        exec() might read past the end of the data buffer in UTF-8 mode.
349    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
350        the data contained the byte 0x85 as part of a UTF-8 character within its
351        first line. This applied both to normal and DFA matching.
353    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
354        /^[^d]*?$/8 failed to match "abc".
356    16. Added a missing copyright notice to pcrecpp_internal.h.
358    17. Make it more clear in the documentation that values returned from
359        pcre_exec() in ovector are byte offsets, not character counts.
361    18. Tidied a few places to stop certain compilers from issuing warnings.
363    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
364        supplied by Stefan Weber. I made a further small update for 7.8 because
365        there is a change of source arrangements: the pcre_searchfuncs.c module is
366        replaced by pcre_ucd.c.
369  Version 7.7 07-May-08  Version 7.7 07-May-08

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