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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-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.
34    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35        removed. (These were left over from very, very early versions of PCRE.)
37    7.  Some cosmetic changes to the code to make life easier when compiling it
38        as part of something else:
40        (a) Change DEBUG to PCRE_DEBUG.
42        (b) In pcre_compile(), rename the member of the "branch_chain" structure
43            called "current" as "current_branch", to prevent a collision with the
44            Linux macro when compiled as a kernel module.
46        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
47            prevent a collision with the Linux macro when compiled as a kernel
48            module.
50    8.  In pcre_compile() there are some checks for integer overflows that used to
51        cast potentially large values to (double). This has been changed to that
52        when building, a check for int64_t is made, and if it is found, it is used
53        instead, thus avoiding the use of floating point arithmetic. (There is no
54        other use of FP in PCRE.) If int64_t is not found, the fallback is to
55        double.
57    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
58        2005 (difference between two addresses compared to an unsigned value).
60    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
61        custom one, because of the following reported problem in Windows:
63          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
64            under Win32.
65          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
66            therefore missing the function definition.
67          - The compiler thus generates a "C" signature for the test function.
68          - The linker fails to find the "C" function.
69          - PCRE fails to configure if asked to do so against libbz2.
71    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
72        messages were output:
74          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
75          rerunning libtoolize, to keep the correct libtool macros in-tree.
76          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
78        I have done both of these things.
80    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
81        most of the time, it *can* run out if it is given a pattern that contains a
82        runaway infinite recursion. I updated the discussion in the pcrestack man
83        page.
85    13. Now that we have gone to the x.xx style of version numbers, the minor
86        version may start with zero. Using 08 or 09 is a bad idea because users
87        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
88        interpreted as invalid octal numbers. I've updated the previous comment in
89        configure.ac, and also added a check that gives an error if 08 or 09 are
90        used.
92    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
93        causing partial matching to fail when the end of the subject matched \W
94        in a UTF-8 pattern where \W was quantified with a minimum of 3.
96    15. There were some discrepancies between the declarations in pcre_internal.h
97        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
98        their definitions. The declarations used "const uschar *" and the
99        definitions used USPTR. Even though USPTR is normally defined as "const
100        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
101        reported that: "This difference in casting confuses some C++ compilers, for
102        example, SunCC recognizes above declarations as different functions and
103        generates broken code for hbpcre." I have changed the declarations to use
104        USPTR.
109    Version 8.00 19-Oct-09
110    ----------------------
112    1.  The table for translating pcre_compile() error codes into POSIX error codes
113        was out-of-date, and there was no check on the pcre_compile() error code
114        being within the table. This could lead to an OK return being given in
115        error.
117    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
118        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
119        in a Windows environment.
121    3.  The pcregrep --count option prints the count for each file even when it is
122        zero, as does GNU grep. However, pcregrep was also printing all files when
123        --files-with-matches was added. Now, when both options are given, it prints
124        counts only for those files that have at least one match. (GNU grep just
125        prints the file name in this circumstance, but including the count seems
126        more useful - otherwise, why use --count?) Also ensured that the
127        combination -clh just lists non-zero counts, with no names.
129    4.  The long form of the pcregrep -F option was incorrectly implemented as
130        --fixed_strings instead of --fixed-strings. This is an incompatible change,
131        but it seems right to fix it, and I didn't think it was worth preserving
132        the old behaviour.
134    5.  The command line items --regex=pattern and --regexp=pattern were not
135        recognized by pcregrep, which required --regex pattern or --regexp pattern
136        (with a space rather than an '='). The man page documented the '=' forms,
137        which are compatible with GNU grep; these now work.
139    6.  No libpcreposix.pc file was created for pkg-config; there was just
140        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
142    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
143        when UCP support is not needed, by modifying the Python script that
144        generates it from Unicode data files. This should not matter if the module
145        is correctly used as a library, but I received one complaint about 50K of
146        unwanted data. My guess is that the person linked everything into his
147        program rather than using a library. Anyway, it does no harm.
149    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
150        was a minimum greater than 1 for a wide character in a possessive
151        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
152        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
153        character. Chaos in the form of incorrect output or a compiling loop could
154        result.
156    9.  The restrictions on what a pattern can contain when partial matching is
157        requested for pcre_exec() have been removed. All patterns can now be
158        partially matched by this function. In addition, if there are at least two
159        slots in the offset vector, the offset of the earliest inspected character
160        for the match and the offset of the end of the subject are set in them when
161        PCRE_ERROR_PARTIAL is returned.
163    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
164        synonymous with PCRE_PARTIAL, for backwards compatibility, and
165        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
166        and may be more useful for multi-segment matching.
168    11. Partial matching with pcre_exec() is now more intuitive. A partial match
169        used to be given if ever the end of the subject was reached; now it is
170        given only if matching could not proceed because another character was
171        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
172        string "Z", which now yields "no match" instead of "partial match". In the
173        case of pcre_dfa_exec(), "no match" is given if every matching path for the
174        final character ended with (*FAIL).
176    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
177        if the pattern had a "must contain" character that was already found in the
178        earlier partial match, unless partial matching was again requested. For
179        example, with the pattern /dog.(body)?/, the "must contain" character is
180        "g". If the first part-match was for the string "dog", restarting with
181        "sbody" failed. This bug has been fixed.
183    13. The string returned by pcre_dfa_exec() after a partial match has been
184        changed so that it starts at the first inspected character rather than the
185        first character of the match. This makes a difference only if the pattern
186        starts with a lookbehind assertion or \b or \B (\K is not supported by
187        pcre_dfa_exec()). It's an incompatible change, but it makes the two
188        matching functions compatible, and I think it's the right thing to do.
190    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
191        so that the demonstration program is easily available in environments where
192        PCRE has not been installed from source.
194    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
195        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
196        library.
198    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
199        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
200        is not the first non-POSIX option to be added. Clearly some people find
201        these options useful.
203    17. If a caller to the POSIX matching function regexec() passes a non-zero
204        value for nmatch with a NULL value for pmatch, the value of
205        nmatch is forced to zero.
207    18. RunGrepTest did not have a test for the availability of the -u option of
208        the diff command, as RunTest does. It now checks in the same way as
209        RunTest, and also checks for the -b option.
211    19. If an odd number of negated classes containing just a single character
212        interposed, within parentheses, between a forward reference to a named
213        subpattern and the definition of the subpattern, compilation crashed with
214        an internal error, complaining that it could not find the referenced
215        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
216        [The bug was that it was starting one character too far in when skipping
217        over the character class, thus treating the ] as data rather than
218        terminating the class. This meant it could skip too much.]
220    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
221        /g option in pcretest when the pattern contains \K, which makes it possible
222        to have an empty string match not at the start, even when the pattern is
223        anchored. Updated pcretest and pcredemo to use this option.
225    21. If the maximum number of capturing subpatterns in a recursion was greater
226        than the maximum at the outer level, the higher number was returned, but
227        with unset values at the outer level. The correct (outer level) value is
228        now given.
230    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
231        PCRE did not set those parentheses (unlike Perl). I have now found a way to
232        make it do so. The string so far is captured, making this feature
233        compatible with Perl.
235    23. The tests have been re-organized, adding tests 11 and 12, to make it
236        possible to check the Perl 5.10 features against Perl 5.10.
238    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
239        pattern matches a fixed length string. PCRE did not allow this; now it
240        does. Neither allows recursion.
242    25. I finally figured out how to implement a request to provide the minimum
243        length of subject string that was needed in order to match a given pattern.
244        (It was back references and recursion that I had previously got hung up
245        on.) This code has now been added to pcre_study(); it finds a lower bound
246        to the length of subject needed. It is not necessarily the greatest lower
247        bound, but using it to avoid searching strings that are too short does give
248        some useful speed-ups. The value is available to calling programs via
249        pcre_fullinfo().
251    26. While implementing 25, I discovered to my embarrassment that pcretest had
252        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
253        study optimizations had never been tested with that matching function.
254        Oops. What is worse, even when it was passed study data, there was a bug in
255        pcre_dfa_exec() that meant it never actually used it. Double oops. There
256        were also very few tests of studied patterns with pcre_dfa_exec().
258    27. If (?| is used to create subpatterns with duplicate numbers, they are now
259        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
260        on the other side of the coin, they are no longer allowed to have different
261        names, because these cannot be distinguished in PCRE, and this has caused
262        confusion. (This is a difference from Perl.)
264    28. When duplicate subpattern names are present (necessarily with different
265        numbers, as required by 27 above), and a test is made by name in a
266        conditional pattern, either for a subpattern having been matched, or for
267        recursion in such a pattern, all the associated numbered subpatterns are
268        tested, and the overall condition is true if the condition is true for any
269        one of them. This is the way Perl works, and is also more like the way
270        testing by number works.
273    Version 7.9 11-Apr-09
274    ---------------------
276    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
277        (pcretest), all targets were linked against these libraries. This included
278        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
279        libraries. This caused unwanted dependencies to be created. This problem
280        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
281        pcretest is linked with readline.
283    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
284        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
285        moved outside it again, because FALSE and TRUE are already defined in AIX,
286        but BOOL is not.
288    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
289        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
291    4.  The pcregrep documentation said spaces were inserted as well as colons (or
292        hyphens) following file names and line numbers when outputting matching
293        lines. This is not true; no spaces are inserted. I have also clarified the
294        wording for the --colour (or --color) option.
296    5.  In pcregrep, when --colour was used with -o, the list of matching strings
297        was not coloured; this is different to GNU grep, so I have changed it to be
298        the same.
300    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
301        each matching line was coloured. Now it goes on to look for further matches
302        of any of the test patterns, which is the same behaviour as GNU grep.
304    7.  A pattern that could match an empty string could cause pcregrep to loop; it
305        doesn't make sense to accept an empty string match in pcregrep, so I have
306        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
307        seems to be how GNU grep behaves.
309    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
310        start or after a newline", because the conditional assertion was not being
311        correctly handled. The rule now is that both the assertion and what follows
312        in the first alternative must satisfy the test.
314    9.  If auto-callout was enabled in a pattern with a conditional group whose
315        condition was an assertion, PCRE could crash during matching, both with
316        pcre_exec() and pcre_dfa_exec().
318    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
319        used for matching.
321    11. Unicode property support in character classes was not working for
322        characters (bytes) greater than 127 when not in UTF-8 mode.
324    12. Added the -M command line option to pcretest.
326    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
328    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
330    16. Added comments and documentation about mis-use of no_arg in the C++
331        wrapper.
333    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
334        from Martin Jerabek that uses macro names for all relevant character and
335        string constants.
337    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
338        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
339        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
340        these, but not everybody uses configure.
342    19. A conditional group that had only one branch was not being correctly
343        recognized as an item that could match an empty string. This meant that an
344        enclosing group might also not be so recognized, causing infinite looping
345        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
346        with the subject "ab", where knowledge that the repeated group can match
347        nothing is needed in order to break the loop.
349    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
350        exec(), but without supplying a callout function, matching went wrong.
352    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
353        leak if the size of the offset vector was greater than 30. When the vector
354        is smaller, the saved offsets during recursion go onto a local stack
355        vector, but for larger vectors malloc() is used. It was failing to free
356        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
357        error, in fact).
359    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
360        heapframe that is used only when UTF-8 support is enabled. This caused no
361        problem, but was untidy.
363    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
364        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
365        included within another project.
367    24. Steven Van Ingelgem's patches to add more options to the CMake support,
368        slightly modified by me:
370          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
371              not building pcregrep.
373          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
374              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
376    25. Forward references, both numeric and by name, in patterns that made use of
377        duplicate group numbers, could behave incorrectly or give incorrect errors,
378        because when scanning forward to find the reference group, PCRE was not
379        taking into account the duplicate group numbers. A pattern such as
380        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
382    26. Changed a few more instances of "const unsigned char *" to USPTR, making
383        the feature of a custom pointer more persuasive (as requested by a user).
385    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
386        pcretest.c, inside #ifndefs, because it seems they are sometimes already
387        pre-defined.
389    28. Added support for (*UTF8) at the start of a pattern.
391    29. Arrange for flags added by the "release type" setting in CMake to be shown
392        in the configuration summary.
395    Version 7.8 05-Sep-08
396  ---------------------  ---------------------
398  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 404  Version 8.0 02 Jul-08
405  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
406      scripts.      scripts.
408  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
409      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,
410      or the function might crash, depending on the pattern.      or the function might crash, depending on the pattern.
412    4.  Caseless matching was not working for non-ASCII characters in back
413        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
414        It now works when Unicode Property Support is available.
416    5.  In pcretest, an escape such as \x{de} in the data was always generating
417        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
418        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
419        truncation.
421    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
423    7.  Added two (int) casts to pcregrep when printing the difference of two
424        pointers, in case they are 64-bit values.
426    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
427        test 2 if it fails.
429    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
430        and a #define of that name to empty if it is not externally set. This is to
431        allow users of MSVC to set it if necessary.
433    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
434        the convenience functions in the pcre_get.c source file.
436    11. An option change at the start of a pattern that had top-level alternatives
437        could cause overwriting and/or a crash. This command provoked a crash in
438        some environments:
440          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
442        This potential security problem was recorded as CVE-2008-2371.
444    12. For a pattern where the match had to start at the beginning or immediately
445        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
446        pcre_dfa_exec() could read past the end of the passed subject if there was
447        no match. To help with detecting such bugs (e.g. with valgrind), I modified
448        pcretest so that it places the subject at the end of its malloc-ed buffer.
450    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
451        exec() might read past the end of the data buffer in UTF-8 mode.
453    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
454        the data contained the byte 0x85 as part of a UTF-8 character within its
455        first line. This applied both to normal and DFA matching.
457    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
458        /^[^d]*?$/8 failed to match "abc".
460    16. Added a missing copyright notice to pcrecpp_internal.h.
462    17. Make it more clear in the documentation that values returned from
463        pcre_exec() in ovector are byte offsets, not character counts.
465    18. Tidied a few places to stop certain compilers from issuing warnings.
467    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
468        supplied by Stefan Weber. I made a further small update for 7.8 because
469        there is a change of source arrangements: the pcre_searchfuncs.c module is
470        replaced by pcre_ucd.c.
473  Version 7.7 07-May-08  Version 7.7 07-May-08

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