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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.
82    Version 8.00 19-Oct-09
83    ----------------------
85    1.  The table for translating pcre_compile() error codes into POSIX error codes
86        was out-of-date, and there was no check on the pcre_compile() error code
87        being within the table. This could lead to an OK return being given in
88        error.
90    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
91        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
92        in a Windows environment.
94    3.  The pcregrep --count option prints the count for each file even when it is
95        zero, as does GNU grep. However, pcregrep was also printing all files when
96        --files-with-matches was added. Now, when both options are given, it prints
97        counts only for those files that have at least one match. (GNU grep just
98        prints the file name in this circumstance, but including the count seems
99        more useful - otherwise, why use --count?) Also ensured that the
100        combination -clh just lists non-zero counts, with no names.
102    4.  The long form of the pcregrep -F option was incorrectly implemented as
103        --fixed_strings instead of --fixed-strings. This is an incompatible change,
104        but it seems right to fix it, and I didn't think it was worth preserving
105        the old behaviour.
107    5.  The command line items --regex=pattern and --regexp=pattern were not
108        recognized by pcregrep, which required --regex pattern or --regexp pattern
109        (with a space rather than an '='). The man page documented the '=' forms,
110        which are compatible with GNU grep; these now work.
112    6.  No libpcreposix.pc file was created for pkg-config; there was just
113        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
115    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
116        when UCP support is not needed, by modifying the Python script that
117        generates it from Unicode data files. This should not matter if the module
118        is correctly used as a library, but I received one complaint about 50K of
119        unwanted data. My guess is that the person linked everything into his
120        program rather than using a library. Anyway, it does no harm.
122    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
123        was a minimum greater than 1 for a wide character in a possessive
124        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
125        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
126        character. Chaos in the form of incorrect output or a compiling loop could
127        result.
129    9.  The restrictions on what a pattern can contain when partial matching is
130        requested for pcre_exec() have been removed. All patterns can now be
131        partially matched by this function. In addition, if there are at least two
132        slots in the offset vector, the offset of the earliest inspected character
133        for the match and the offset of the end of the subject are set in them when
134        PCRE_ERROR_PARTIAL is returned.
136    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
137        synonymous with PCRE_PARTIAL, for backwards compatibility, and
138        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
139        and may be more useful for multi-segment matching.
141    11. Partial matching with pcre_exec() is now more intuitive. A partial match
142        used to be given if ever the end of the subject was reached; now it is
143        given only if matching could not proceed because another character was
144        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
145        string "Z", which now yields "no match" instead of "partial match". In the
146        case of pcre_dfa_exec(), "no match" is given if every matching path for the
147        final character ended with (*FAIL).
149    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
150        if the pattern had a "must contain" character that was already found in the
151        earlier partial match, unless partial matching was again requested. For
152        example, with the pattern /dog.(body)?/, the "must contain" character is
153        "g". If the first part-match was for the string "dog", restarting with
154        "sbody" failed. This bug has been fixed.
156    13. The string returned by pcre_dfa_exec() after a partial match has been
157        changed so that it starts at the first inspected character rather than the
158        first character of the match. This makes a difference only if the pattern
159        starts with a lookbehind assertion or \b or \B (\K is not supported by
160        pcre_dfa_exec()). It's an incompatible change, but it makes the two
161        matching functions compatible, and I think it's the right thing to do.
163    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
164        so that the demonstration program is easily available in environments where
165        PCRE has not been installed from source.
167    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
168        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
169        library.
171    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
172        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
173        is not the first non-POSIX option to be added. Clearly some people find
174        these options useful.
176    17. If a caller to the POSIX matching function regexec() passes a non-zero
177        value for nmatch with a NULL value for pmatch, the value of
178        nmatch is forced to zero.
180    18. RunGrepTest did not have a test for the availability of the -u option of
181        the diff command, as RunTest does. It now checks in the same way as
182        RunTest, and also checks for the -b option.
184    19. If an odd number of negated classes containing just a single character
185        interposed, within parentheses, between a forward reference to a named
186        subpattern and the definition of the subpattern, compilation crashed with
187        an internal error, complaining that it could not find the referenced
188        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
189        [The bug was that it was starting one character too far in when skipping
190        over the character class, thus treating the ] as data rather than
191        terminating the class. This meant it could skip too much.]
193    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
194        /g option in pcretest when the pattern contains \K, which makes it possible
195        to have an empty string match not at the start, even when the pattern is
196        anchored. Updated pcretest and pcredemo to use this option.
198    21. If the maximum number of capturing subpatterns in a recursion was greater
199        than the maximum at the outer level, the higher number was returned, but
200        with unset values at the outer level. The correct (outer level) value is
201        now given.
203    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
204        PCRE did not set those parentheses (unlike Perl). I have now found a way to
205        make it do so. The string so far is captured, making this feature
206        compatible with Perl.
208    23. The tests have been re-organized, adding tests 11 and 12, to make it
209        possible to check the Perl 5.10 features against Perl 5.10.
211    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
212        pattern matches a fixed length string. PCRE did not allow this; now it
213        does. Neither allows recursion.
215    25. I finally figured out how to implement a request to provide the minimum
216        length of subject string that was needed in order to match a given pattern.
217        (It was back references and recursion that I had previously got hung up
218        on.) This code has now been added to pcre_study(); it finds a lower bound
219        to the length of subject needed. It is not necessarily the greatest lower
220        bound, but using it to avoid searching strings that are too short does give
221        some useful speed-ups. The value is available to calling programs via
222        pcre_fullinfo().
224    26. While implementing 25, I discovered to my embarrassment that pcretest had
225        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
226        study optimizations had never been tested with that matching function.
227        Oops. What is worse, even when it was passed study data, there was a bug in
228        pcre_dfa_exec() that meant it never actually used it. Double oops. There
229        were also very few tests of studied patterns with pcre_dfa_exec().
231    27. If (?| is used to create subpatterns with duplicate numbers, they are now
232        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
233        on the other side of the coin, they are no longer allowed to have different
234        names, because these cannot be distinguished in PCRE, and this has caused
235        confusion. (This is a difference from Perl.)
237    28. When duplicate subpattern names are present (necessarily with different
238        numbers, as required by 27 above), and a test is made by name in a
239        conditional pattern, either for a subpattern having been matched, or for
240        recursion in such a pattern, all the associated numbered subpatterns are
241        tested, and the overall condition is true if the condition is true for any
242        one of them. This is the way Perl works, and is also more like the way
243        testing by number works.
246    Version 7.9 11-Apr-09
247    ---------------------
249    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
250        (pcretest), all targets were linked against these libraries. This included
251        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
252        libraries. This caused unwanted dependencies to be created. This problem
253        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
254        pcretest is linked with readline.
256    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
257        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
258        moved outside it again, because FALSE and TRUE are already defined in AIX,
259        but BOOL is not.
261    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
262        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
264    4.  The pcregrep documentation said spaces were inserted as well as colons (or
265        hyphens) following file names and line numbers when outputting matching
266        lines. This is not true; no spaces are inserted. I have also clarified the
267        wording for the --colour (or --color) option.
269    5.  In pcregrep, when --colour was used with -o, the list of matching strings
270        was not coloured; this is different to GNU grep, so I have changed it to be
271        the same.
273    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
274        each matching line was coloured. Now it goes on to look for further matches
275        of any of the test patterns, which is the same behaviour as GNU grep.
277    7.  A pattern that could match an empty string could cause pcregrep to loop; it
278        doesn't make sense to accept an empty string match in pcregrep, so I have
279        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
280        seems to be how GNU grep behaves.
282    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
283        start or after a newline", because the conditional assertion was not being
284        correctly handled. The rule now is that both the assertion and what follows
285        in the first alternative must satisfy the test.
287    9.  If auto-callout was enabled in a pattern with a conditional group whose
288        condition was an assertion, PCRE could crash during matching, both with
289        pcre_exec() and pcre_dfa_exec().
291    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
292        used for matching.
294    11. Unicode property support in character classes was not working for
295        characters (bytes) greater than 127 when not in UTF-8 mode.
297    12. Added the -M command line option to pcretest.
299    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
301    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
303    16. Added comments and documentation about mis-use of no_arg in the C++
304        wrapper.
306    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
307        from Martin Jerabek that uses macro names for all relevant character and
308        string constants.
310    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
311        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
312        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
313        these, but not everybody uses configure.
315    19. A conditional group that had only one branch was not being correctly
316        recognized as an item that could match an empty string. This meant that an
317        enclosing group might also not be so recognized, causing infinite looping
318        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
319        with the subject "ab", where knowledge that the repeated group can match
320        nothing is needed in order to break the loop.
322    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
323        exec(), but without supplying a callout function, matching went wrong.
325    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
326        leak if the size of the offset vector was greater than 30. When the vector
327        is smaller, the saved offsets during recursion go onto a local stack
328        vector, but for larger vectors malloc() is used. It was failing to free
329        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
330        error, in fact).
332    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
333        heapframe that is used only when UTF-8 support is enabled. This caused no
334        problem, but was untidy.
336    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
337        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
338        included within another project.
340    24. Steven Van Ingelgem's patches to add more options to the CMake support,
341        slightly modified by me:
343          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
344              not building pcregrep.
346          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
347              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
349    25. Forward references, both numeric and by name, in patterns that made use of
350        duplicate group numbers, could behave incorrectly or give incorrect errors,
351        because when scanning forward to find the reference group, PCRE was not
352        taking into account the duplicate group numbers. A pattern such as
353        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
355    26. Changed a few more instances of "const unsigned char *" to USPTR, making
356        the feature of a custom pointer more persuasive (as requested by a user).
358    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
359        pcretest.c, inside #ifndefs, because it seems they are sometimes already
360        pre-defined.
362    28. Added support for (*UTF8) at the start of a pattern.
364    29. Arrange for flags added by the "release type" setting in CMake to be shown
365        in the configuration summary.
368    Version 7.8 05-Sep-08
369  ---------------------  ---------------------
371  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
372      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
373      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
374      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
375      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
376      the tarball, but is in the Subversion repository).      the tarball, but is in the Subversion repository).
378    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
379        scripts.
381    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
382        a group with a zero qualifier. The result of the study could be incorrect,
383        or the function might crash, depending on the pattern.
385    4.  Caseless matching was not working for non-ASCII characters in back
386        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
387        It now works when Unicode Property Support is available.
389    5.  In pcretest, an escape such as \x{de} in the data was always generating
390        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
391        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
392        truncation.
394    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
396    7.  Added two (int) casts to pcregrep when printing the difference of two
397        pointers, in case they are 64-bit values.
399    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
400        test 2 if it fails.
402    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
403        and a #define of that name to empty if it is not externally set. This is to
404        allow users of MSVC to set it if necessary.
406    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
407        the convenience functions in the pcre_get.c source file.
409    11. An option change at the start of a pattern that had top-level alternatives
410        could cause overwriting and/or a crash. This command provoked a crash in
411        some environments:
413          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
415        This potential security problem was recorded as CVE-2008-2371.
417    12. For a pattern where the match had to start at the beginning or immediately
418        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
419        pcre_dfa_exec() could read past the end of the passed subject if there was
420        no match. To help with detecting such bugs (e.g. with valgrind), I modified
421        pcretest so that it places the subject at the end of its malloc-ed buffer.
423    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
424        exec() might read past the end of the data buffer in UTF-8 mode.
426    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
427        the data contained the byte 0x85 as part of a UTF-8 character within its
428        first line. This applied both to normal and DFA matching.
430    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
431        /^[^d]*?$/8 failed to match "abc".
433    16. Added a missing copyright notice to pcrecpp_internal.h.
435    17. Make it more clear in the documentation that values returned from
436        pcre_exec() in ovector are byte offsets, not character counts.
438    18. Tidied a few places to stop certain compilers from issuing warnings.
440    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
441        supplied by Stefan Weber. I made a further small update for 7.8 because
442        there is a change of source arrangements: the pcre_searchfuncs.c module is
443        replaced by pcre_ucd.c.
446  Version 7.7 07-May-08  Version 7.7 07-May-08

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