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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.7 28-Apr-08  Version 8.01 11-Dec-09
5    ----------------------
7    1.  If a pattern contained a conditional subpattern with only one branch (in
8        particular, this includes all (DEFINE) patterns), a call to pcre_study()
9        computed the wrong minimum data length (which is of course zero for such
10        subpatterns).
12    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13        the pattern is reset in the first branch, pcre_compile() failed with
14        "internal error: code overflow at offset...". This happened only when
15        the reset was to the original external option setting. (An optimization
16        abstracts leading options settings into an external setting, which was the
17        cause of this.)
19    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21        assertion pattern did not match (meaning that the assertion was true), it
22        was incorrectly treated as false if the SKIP had been reached during the
23        matching. This also applied to assertions used as conditions.
25    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
26        assertion subpattern, including such a pattern used as a condition,
27        unpredictable results occurred, instead of the error return
30    5.  The C++ GlobalReplace function was not working like Perl for the special
31        situation when an empty string is matched. It now does the fancy magic
32        stuff that is necessary.
35    Version 8.00 19-Oct-09
36    ----------------------
38    1.  The table for translating pcre_compile() error codes into POSIX error codes
39        was out-of-date, and there was no check on the pcre_compile() error code
40        being within the table. This could lead to an OK return being given in
41        error.
43    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
44        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
45        in a Windows environment.
47    3.  The pcregrep --count option prints the count for each file even when it is
48        zero, as does GNU grep. However, pcregrep was also printing all files when
49        --files-with-matches was added. Now, when both options are given, it prints
50        counts only for those files that have at least one match. (GNU grep just
51        prints the file name in this circumstance, but including the count seems
52        more useful - otherwise, why use --count?) Also ensured that the
53        combination -clh just lists non-zero counts, with no names.
55    4.  The long form of the pcregrep -F option was incorrectly implemented as
56        --fixed_strings instead of --fixed-strings. This is an incompatible change,
57        but it seems right to fix it, and I didn't think it was worth preserving
58        the old behaviour.
60    5.  The command line items --regex=pattern and --regexp=pattern were not
61        recognized by pcregrep, which required --regex pattern or --regexp pattern
62        (with a space rather than an '='). The man page documented the '=' forms,
63        which are compatible with GNU grep; these now work.
65    6.  No libpcreposix.pc file was created for pkg-config; there was just
66        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
68    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
69        when UCP support is not needed, by modifying the Python script that
70        generates it from Unicode data files. This should not matter if the module
71        is correctly used as a library, but I received one complaint about 50K of
72        unwanted data. My guess is that the person linked everything into his
73        program rather than using a library. Anyway, it does no harm.
75    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
76        was a minimum greater than 1 for a wide character in a possessive
77        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
78        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
79        character. Chaos in the form of incorrect output or a compiling loop could
80        result.
82    9.  The restrictions on what a pattern can contain when partial matching is
83        requested for pcre_exec() have been removed. All patterns can now be
84        partially matched by this function. In addition, if there are at least two
85        slots in the offset vector, the offset of the earliest inspected character
86        for the match and the offset of the end of the subject are set in them when
87        PCRE_ERROR_PARTIAL is returned.
89    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
90        synonymous with PCRE_PARTIAL, for backwards compatibility, and
91        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
92        and may be more useful for multi-segment matching.
94    11. Partial matching with pcre_exec() is now more intuitive. A partial match
95        used to be given if ever the end of the subject was reached; now it is
96        given only if matching could not proceed because another character was
97        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
98        string "Z", which now yields "no match" instead of "partial match". In the
99        case of pcre_dfa_exec(), "no match" is given if every matching path for the
100        final character ended with (*FAIL).
102    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
103        if the pattern had a "must contain" character that was already found in the
104        earlier partial match, unless partial matching was again requested. For
105        example, with the pattern /dog.(body)?/, the "must contain" character is
106        "g". If the first part-match was for the string "dog", restarting with
107        "sbody" failed. This bug has been fixed.
109    13. The string returned by pcre_dfa_exec() after a partial match has been
110        changed so that it starts at the first inspected character rather than the
111        first character of the match. This makes a difference only if the pattern
112        starts with a lookbehind assertion or \b or \B (\K is not supported by
113        pcre_dfa_exec()). It's an incompatible change, but it makes the two
114        matching functions compatible, and I think it's the right thing to do.
116    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
117        so that the demonstration program is easily available in environments where
118        PCRE has not been installed from source.
120    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
121        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
122        library.
124    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
125        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
126        is not the first non-POSIX option to be added. Clearly some people find
127        these options useful.
129    17. If a caller to the POSIX matching function regexec() passes a non-zero
130        value for nmatch with a NULL value for pmatch, the value of
131        nmatch is forced to zero.
133    18. RunGrepTest did not have a test for the availability of the -u option of
134        the diff command, as RunTest does. It now checks in the same way as
135        RunTest, and also checks for the -b option.
137    19. If an odd number of negated classes containing just a single character
138        interposed, within parentheses, between a forward reference to a named
139        subpattern and the definition of the subpattern, compilation crashed with
140        an internal error, complaining that it could not find the referenced
141        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
142        [The bug was that it was starting one character too far in when skipping
143        over the character class, thus treating the ] as data rather than
144        terminating the class. This meant it could skip too much.]
146    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
147        /g option in pcretest when the pattern contains \K, which makes it possible
148        to have an empty string match not at the start, even when the pattern is
149        anchored. Updated pcretest and pcredemo to use this option.
151    21. If the maximum number of capturing subpatterns in a recursion was greater
152        than the maximum at the outer level, the higher number was returned, but
153        with unset values at the outer level. The correct (outer level) value is
154        now given.
156    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
157        PCRE did not set those parentheses (unlike Perl). I have now found a way to
158        make it do so. The string so far is captured, making this feature
159        compatible with Perl.
161    23. The tests have been re-organized, adding tests 11 and 12, to make it
162        possible to check the Perl 5.10 features against Perl 5.10.
164    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
165        pattern matches a fixed length string. PCRE did not allow this; now it
166        does. Neither allows recursion.
168    25. I finally figured out how to implement a request to provide the minimum
169        length of subject string that was needed in order to match a given pattern.
170        (It was back references and recursion that I had previously got hung up
171        on.) This code has now been added to pcre_study(); it finds a lower bound
172        to the length of subject needed. It is not necessarily the greatest lower
173        bound, but using it to avoid searching strings that are too short does give
174        some useful speed-ups. The value is available to calling programs via
175        pcre_fullinfo().
177    26. While implementing 25, I discovered to my embarrassment that pcretest had
178        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
179        study optimizations had never been tested with that matching function.
180        Oops. What is worse, even when it was passed study data, there was a bug in
181        pcre_dfa_exec() that meant it never actually used it. Double oops. There
182        were also very few tests of studied patterns with pcre_dfa_exec().
184    27. If (?| is used to create subpatterns with duplicate numbers, they are now
185        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
186        on the other side of the coin, they are no longer allowed to have different
187        names, because these cannot be distinguished in PCRE, and this has caused
188        confusion. (This is a difference from Perl.)
190    28. When duplicate subpattern names are present (necessarily with different
191        numbers, as required by 27 above), and a test is made by name in a
192        conditional pattern, either for a subpattern having been matched, or for
193        recursion in such a pattern, all the associated numbered subpatterns are
194        tested, and the overall condition is true if the condition is true for any
195        one of them. This is the way Perl works, and is also more like the way
196        testing by number works.
199    Version 7.9 11-Apr-09
200    ---------------------
202    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
203        (pcretest), all targets were linked against these libraries. This included
204        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
205        libraries. This caused unwanted dependencies to be created. This problem
206        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
207        pcretest is linked with readline.
209    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
210        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
211        moved outside it again, because FALSE and TRUE are already defined in AIX,
212        but BOOL is not.
214    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
215        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
217    4.  The pcregrep documentation said spaces were inserted as well as colons (or
218        hyphens) following file names and line numbers when outputting matching
219        lines. This is not true; no spaces are inserted. I have also clarified the
220        wording for the --colour (or --color) option.
222    5.  In pcregrep, when --colour was used with -o, the list of matching strings
223        was not coloured; this is different to GNU grep, so I have changed it to be
224        the same.
226    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
227        each matching line was coloured. Now it goes on to look for further matches
228        of any of the test patterns, which is the same behaviour as GNU grep.
230    7.  A pattern that could match an empty string could cause pcregrep to loop; it
231        doesn't make sense to accept an empty string match in pcregrep, so I have
232        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
233        seems to be how GNU grep behaves.
235    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
236        start or after a newline", because the conditional assertion was not being
237        correctly handled. The rule now is that both the assertion and what follows
238        in the first alternative must satisfy the test.
240    9.  If auto-callout was enabled in a pattern with a conditional group whose
241        condition was an assertion, PCRE could crash during matching, both with
242        pcre_exec() and pcre_dfa_exec().
244    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
245        used for matching.
247    11. Unicode property support in character classes was not working for
248        characters (bytes) greater than 127 when not in UTF-8 mode.
250    12. Added the -M command line option to pcretest.
252    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
254    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
256    16. Added comments and documentation about mis-use of no_arg in the C++
257        wrapper.
259    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
260        from Martin Jerabek that uses macro names for all relevant character and
261        string constants.
263    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
264        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
265        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
266        these, but not everybody uses configure.
268    19. A conditional group that had only one branch was not being correctly
269        recognized as an item that could match an empty string. This meant that an
270        enclosing group might also not be so recognized, causing infinite looping
271        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
272        with the subject "ab", where knowledge that the repeated group can match
273        nothing is needed in order to break the loop.
275    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
276        exec(), but without supplying a callout function, matching went wrong.
278    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
279        leak if the size of the offset vector was greater than 30. When the vector
280        is smaller, the saved offsets during recursion go onto a local stack
281        vector, but for larger vectors malloc() is used. It was failing to free
282        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
283        error, in fact).
285    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
286        heapframe that is used only when UTF-8 support is enabled. This caused no
287        problem, but was untidy.
289    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
290        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
291        included within another project.
293    24. Steven Van Ingelgem's patches to add more options to the CMake support,
294        slightly modified by me:
296          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
297              not building pcregrep.
299          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
300              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
302    25. Forward references, both numeric and by name, in patterns that made use of
303        duplicate group numbers, could behave incorrectly or give incorrect errors,
304        because when scanning forward to find the reference group, PCRE was not
305        taking into account the duplicate group numbers. A pattern such as
306        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
308    26. Changed a few more instances of "const unsigned char *" to USPTR, making
309        the feature of a custom pointer more persuasive (as requested by a user).
311    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
312        pcretest.c, inside #ifndefs, because it seems they are sometimes already
313        pre-defined.
315    28. Added support for (*UTF8) at the start of a pattern.
317    29. Arrange for flags added by the "release type" setting in CMake to be shown
318        in the configuration summary.
321    Version 7.8 05-Sep-08
322    ---------------------
324    1.  Replaced UCP searching code with optimized version as implemented for Ad
325        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
326        stage table and inline lookup instead of a function, giving speed ups of 2
327        to 5 times on some simple patterns that I tested. Permission was given to
328        distribute the MultiStage2.py script that generates the tables (it's not in
329        the tarball, but is in the Subversion repository).
331    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
332        scripts.
334    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
335        a group with a zero qualifier. The result of the study could be incorrect,
336        or the function might crash, depending on the pattern.
338    4.  Caseless matching was not working for non-ASCII characters in back
339        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
340        It now works when Unicode Property Support is available.
342    5.  In pcretest, an escape such as \x{de} in the data was always generating
343        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
344        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
345        truncation.
347    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
349    7.  Added two (int) casts to pcregrep when printing the difference of two
350        pointers, in case they are 64-bit values.
352    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
353        test 2 if it fails.
355    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
356        and a #define of that name to empty if it is not externally set. This is to
357        allow users of MSVC to set it if necessary.
359    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
360        the convenience functions in the pcre_get.c source file.
362    11. An option change at the start of a pattern that had top-level alternatives
363        could cause overwriting and/or a crash. This command provoked a crash in
364        some environments:
366          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
368        This potential security problem was recorded as CVE-2008-2371.
370    12. For a pattern where the match had to start at the beginning or immediately
371        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
372        pcre_dfa_exec() could read past the end of the passed subject if there was
373        no match. To help with detecting such bugs (e.g. with valgrind), I modified
374        pcretest so that it places the subject at the end of its malloc-ed buffer.
376    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
377        exec() might read past the end of the data buffer in UTF-8 mode.
379    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
380        the data contained the byte 0x85 as part of a UTF-8 character within its
381        first line. This applied both to normal and DFA matching.
383    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
384        /^[^d]*?$/8 failed to match "abc".
386    16. Added a missing copyright notice to pcrecpp_internal.h.
388    17. Make it more clear in the documentation that values returned from
389        pcre_exec() in ovector are byte offsets, not character counts.
391    18. Tidied a few places to stop certain compilers from issuing warnings.
393    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
394        supplied by Stefan Weber. I made a further small update for 7.8 because
395        there is a change of source arrangements: the pcre_searchfuncs.c module is
396        replaced by pcre_ucd.c.
399    Version 7.7 07-May-08
400  ---------------------  ---------------------
402  1.  Applied Craig's patch to sort out a long long problem: "If we can't convert  1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
# Line 103  Version 7.7 28-Apr-08 Line 498  Version 7.7 28-Apr-08
498      requested, but also to allow for it to be overridden. This patch came from      requested, but also to allow for it to be overridden. This patch came from
499      Daniel Bergström.      Daniel Bergström.
501    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
502        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
503        any errors with the current Unicode tables. Thanks to Peter Kankowski for
504        spotting this.
507  Version 7.6 28-Jan-08  Version 7.6 28-Jan-08
508  ---------------------  ---------------------

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