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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 where the end of the subject matched \W.
97    Version 8.00 19-Oct-09
98    ----------------------
100    1.  The table for translating pcre_compile() error codes into POSIX error codes
101        was out-of-date, and there was no check on the pcre_compile() error code
102        being within the table. This could lead to an OK return being given in
103        error.
105    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
106        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
107        in a Windows environment.
109    3.  The pcregrep --count option prints the count for each file even when it is
110        zero, as does GNU grep. However, pcregrep was also printing all files when
111        --files-with-matches was added. Now, when both options are given, it prints
112        counts only for those files that have at least one match. (GNU grep just
113        prints the file name in this circumstance, but including the count seems
114        more useful - otherwise, why use --count?) Also ensured that the
115        combination -clh just lists non-zero counts, with no names.
117    4.  The long form of the pcregrep -F option was incorrectly implemented as
118        --fixed_strings instead of --fixed-strings. This is an incompatible change,
119        but it seems right to fix it, and I didn't think it was worth preserving
120        the old behaviour.
122    5.  The command line items --regex=pattern and --regexp=pattern were not
123        recognized by pcregrep, which required --regex pattern or --regexp pattern
124        (with a space rather than an '='). The man page documented the '=' forms,
125        which are compatible with GNU grep; these now work.
127    6.  No libpcreposix.pc file was created for pkg-config; there was just
128        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
130    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
131        when UCP support is not needed, by modifying the Python script that
132        generates it from Unicode data files. This should not matter if the module
133        is correctly used as a library, but I received one complaint about 50K of
134        unwanted data. My guess is that the person linked everything into his
135        program rather than using a library. Anyway, it does no harm.
137    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
138        was a minimum greater than 1 for a wide character in a possessive
139        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
140        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
141        character. Chaos in the form of incorrect output or a compiling loop could
142        result.
144    9.  The restrictions on what a pattern can contain when partial matching is
145        requested for pcre_exec() have been removed. All patterns can now be
146        partially matched by this function. In addition, if there are at least two
147        slots in the offset vector, the offset of the earliest inspected character
148        for the match and the offset of the end of the subject are set in them when
149        PCRE_ERROR_PARTIAL is returned.
151    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
152        synonymous with PCRE_PARTIAL, for backwards compatibility, and
153        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
154        and may be more useful for multi-segment matching.
156    11. Partial matching with pcre_exec() is now more intuitive. A partial match
157        used to be given if ever the end of the subject was reached; now it is
158        given only if matching could not proceed because another character was
159        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
160        string "Z", which now yields "no match" instead of "partial match". In the
161        case of pcre_dfa_exec(), "no match" is given if every matching path for the
162        final character ended with (*FAIL).
164    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
165        if the pattern had a "must contain" character that was already found in the
166        earlier partial match, unless partial matching was again requested. For
167        example, with the pattern /dog.(body)?/, the "must contain" character is
168        "g". If the first part-match was for the string "dog", restarting with
169        "sbody" failed. This bug has been fixed.
171    13. The string returned by pcre_dfa_exec() after a partial match has been
172        changed so that it starts at the first inspected character rather than the
173        first character of the match. This makes a difference only if the pattern
174        starts with a lookbehind assertion or \b or \B (\K is not supported by
175        pcre_dfa_exec()). It's an incompatible change, but it makes the two
176        matching functions compatible, and I think it's the right thing to do.
178    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
179        so that the demonstration program is easily available in environments where
180        PCRE has not been installed from source.
182    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
183        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
184        library.
186    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
187        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
188        is not the first non-POSIX option to be added. Clearly some people find
189        these options useful.
191    17. If a caller to the POSIX matching function regexec() passes a non-zero
192        value for nmatch with a NULL value for pmatch, the value of
193        nmatch is forced to zero.
195    18. RunGrepTest did not have a test for the availability of the -u option of
196        the diff command, as RunTest does. It now checks in the same way as
197        RunTest, and also checks for the -b option.
199    19. If an odd number of negated classes containing just a single character
200        interposed, within parentheses, between a forward reference to a named
201        subpattern and the definition of the subpattern, compilation crashed with
202        an internal error, complaining that it could not find the referenced
203        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
204        [The bug was that it was starting one character too far in when skipping
205        over the character class, thus treating the ] as data rather than
206        terminating the class. This meant it could skip too much.]
208    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
209        /g option in pcretest when the pattern contains \K, which makes it possible
210        to have an empty string match not at the start, even when the pattern is
211        anchored. Updated pcretest and pcredemo to use this option.
213    21. If the maximum number of capturing subpatterns in a recursion was greater
214        than the maximum at the outer level, the higher number was returned, but
215        with unset values at the outer level. The correct (outer level) value is
216        now given.
218    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
219        PCRE did not set those parentheses (unlike Perl). I have now found a way to
220        make it do so. The string so far is captured, making this feature
221        compatible with Perl.
223    23. The tests have been re-organized, adding tests 11 and 12, to make it
224        possible to check the Perl 5.10 features against Perl 5.10.
226    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
227        pattern matches a fixed length string. PCRE did not allow this; now it
228        does. Neither allows recursion.
230    25. I finally figured out how to implement a request to provide the minimum
231        length of subject string that was needed in order to match a given pattern.
232        (It was back references and recursion that I had previously got hung up
233        on.) This code has now been added to pcre_study(); it finds a lower bound
234        to the length of subject needed. It is not necessarily the greatest lower
235        bound, but using it to avoid searching strings that are too short does give
236        some useful speed-ups. The value is available to calling programs via
237        pcre_fullinfo().
239    26. While implementing 25, I discovered to my embarrassment that pcretest had
240        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
241        study optimizations had never been tested with that matching function.
242        Oops. What is worse, even when it was passed study data, there was a bug in
243        pcre_dfa_exec() that meant it never actually used it. Double oops. There
244        were also very few tests of studied patterns with pcre_dfa_exec().
246    27. If (?| is used to create subpatterns with duplicate numbers, they are now
247        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
248        on the other side of the coin, they are no longer allowed to have different
249        names, because these cannot be distinguished in PCRE, and this has caused
250        confusion. (This is a difference from Perl.)
252    28. When duplicate subpattern names are present (necessarily with different
253        numbers, as required by 27 above), and a test is made by name in a
254        conditional pattern, either for a subpattern having been matched, or for
255        recursion in such a pattern, all the associated numbered subpatterns are
256        tested, and the overall condition is true if the condition is true for any
257        one of them. This is the way Perl works, and is also more like the way
258        testing by number works.
261    Version 7.9 11-Apr-09
262    ---------------------
264    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
265        (pcretest), all targets were linked against these libraries. This included
266        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
267        libraries. This caused unwanted dependencies to be created. This problem
268        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
269        pcretest is linked with readline.
271    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
272        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
273        moved outside it again, because FALSE and TRUE are already defined in AIX,
274        but BOOL is not.
276    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
277        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
279    4.  The pcregrep documentation said spaces were inserted as well as colons (or
280        hyphens) following file names and line numbers when outputting matching
281        lines. This is not true; no spaces are inserted. I have also clarified the
282        wording for the --colour (or --color) option.
284    5.  In pcregrep, when --colour was used with -o, the list of matching strings
285        was not coloured; this is different to GNU grep, so I have changed it to be
286        the same.
288    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
289        each matching line was coloured. Now it goes on to look for further matches
290        of any of the test patterns, which is the same behaviour as GNU grep.
292    7.  A pattern that could match an empty string could cause pcregrep to loop; it
293        doesn't make sense to accept an empty string match in pcregrep, so I have
294        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
295        seems to be how GNU grep behaves.
297    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
298        start or after a newline", because the conditional assertion was not being
299        correctly handled. The rule now is that both the assertion and what follows
300        in the first alternative must satisfy the test.
302    9.  If auto-callout was enabled in a pattern with a conditional group whose
303        condition was an assertion, PCRE could crash during matching, both with
304        pcre_exec() and pcre_dfa_exec().
306    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
307        used for matching.
309    11. Unicode property support in character classes was not working for
310        characters (bytes) greater than 127 when not in UTF-8 mode.
312    12. Added the -M command line option to pcretest.
314    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
316    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
318    16. Added comments and documentation about mis-use of no_arg in the C++
319        wrapper.
321    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
322        from Martin Jerabek that uses macro names for all relevant character and
323        string constants.
325    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
326        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
327        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
328        these, but not everybody uses configure.
330    19. A conditional group that had only one branch was not being correctly
331        recognized as an item that could match an empty string. This meant that an
332        enclosing group might also not be so recognized, causing infinite looping
333        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
334        with the subject "ab", where knowledge that the repeated group can match
335        nothing is needed in order to break the loop.
337    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
338        exec(), but without supplying a callout function, matching went wrong.
340    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
341        leak if the size of the offset vector was greater than 30. When the vector
342        is smaller, the saved offsets during recursion go onto a local stack
343        vector, but for larger vectors malloc() is used. It was failing to free
344        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
345        error, in fact).
347    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
348        heapframe that is used only when UTF-8 support is enabled. This caused no
349        problem, but was untidy.
351    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
352        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
353        included within another project.
355    24. Steven Van Ingelgem's patches to add more options to the CMake support,
356        slightly modified by me:
358          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
359              not building pcregrep.
361          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
362              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
364    25. Forward references, both numeric and by name, in patterns that made use of
365        duplicate group numbers, could behave incorrectly or give incorrect errors,
366        because when scanning forward to find the reference group, PCRE was not
367        taking into account the duplicate group numbers. A pattern such as
368        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
370    26. Changed a few more instances of "const unsigned char *" to USPTR, making
371        the feature of a custom pointer more persuasive (as requested by a user).
373    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
374        pcretest.c, inside #ifndefs, because it seems they are sometimes already
375        pre-defined.
377    28. Added support for (*UTF8) at the start of a pattern.
379    29. Arrange for flags added by the "release type" setting in CMake to be shown
380        in the configuration summary.
383    Version 7.8 05-Sep-08
384  ---------------------  ---------------------
386  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 392  Version 8.0 02 Jul-08
393  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
394      scripts.      scripts.
396  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
397      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,
398      or the function might crash, depending on the pattern.      or the function might crash, depending on the pattern.
400    4.  Caseless matching was not working for non-ASCII characters in back
401        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
402        It now works when Unicode Property Support is available.
404    5.  In pcretest, an escape such as \x{de} in the data was always generating
405        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
406        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
407        truncation.
409    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
411    7.  Added two (int) casts to pcregrep when printing the difference of two
412        pointers, in case they are 64-bit values.
414    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
415        test 2 if it fails.
417    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
418        and a #define of that name to empty if it is not externally set. This is to
419        allow users of MSVC to set it if necessary.
421    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
422        the convenience functions in the pcre_get.c source file.
424    11. An option change at the start of a pattern that had top-level alternatives
425        could cause overwriting and/or a crash. This command provoked a crash in
426        some environments:
428          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
430        This potential security problem was recorded as CVE-2008-2371.
432    12. For a pattern where the match had to start at the beginning or immediately
433        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
434        pcre_dfa_exec() could read past the end of the passed subject if there was
435        no match. To help with detecting such bugs (e.g. with valgrind), I modified
436        pcretest so that it places the subject at the end of its malloc-ed buffer.
438    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
439        exec() might read past the end of the data buffer in UTF-8 mode.
441    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
442        the data contained the byte 0x85 as part of a UTF-8 character within its
443        first line. This applied both to normal and DFA matching.
445    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
446        /^[^d]*?$/8 failed to match "abc".
448    16. Added a missing copyright notice to pcrecpp_internal.h.
450    17. Make it more clear in the documentation that values returned from
451        pcre_exec() in ovector are byte offsets, not character counts.
453    18. Tidied a few places to stop certain compilers from issuing warnings.
455    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
456        supplied by Stefan Weber. I made a further small update for 7.8 because
457        there is a change of source arrangements: the pcre_searchfuncs.c module is
458        replaced by pcre_ucd.c.
461  Version 7.7 07-May-08  Version 7.7 07-May-08

Removed from v.353  
changed lines
  Added in v.482

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