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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-08  Version 8.02 01-Mar-2010
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
9    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
12    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
13        original author of that file, following a query about its status.
15    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
16        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
18    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19        quantifier applied to a forward-referencing subroutine call, could compile
20        incorrect code or give the error "internal error: previously-checked
21        referenced subpattern not found".
23    6.  Both MS Visual Studio and Symbian OS have problems with initializing
24        variables to point to external functions. For these systems, therefore,
25        pcre_malloc etc. are now initialized to local functions that call the
26        relevant global functions.
29    Version 8.01 19-Jan-2010
30    ------------------------
32    1.  If a pattern contained a conditional subpattern with only one branch (in
33        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
34        computed the wrong minimum data length (which is of course zero for such
35        subpatterns). This could cause incorrect "no match" results.
37    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
38        the pattern is reset in the first branch, pcre_compile() failed with
39        "internal error: code overflow at offset...". This happened only when
40        the reset was to the original external option setting. (An optimization
41        abstracts leading options settings into an external setting, which was the
42        cause of this.)
44    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
45        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
46        assertion pattern did not match (meaning that the assertion was true), it
47        was incorrectly treated as false if the SKIP had been reached during the
48        matching. This also applied to assertions used as conditions.
50    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
51        assertion subpattern, including such a pattern used as a condition,
52        unpredictable results occurred, instead of the error return
55    5.  The C++ GlobalReplace function was not working like Perl for the special
56        situation when an empty string is matched. It now does the fancy magic
57        stuff that is necessary.
59    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
60        removed. (These were left over from very, very early versions of PCRE.)
62    7.  Some cosmetic changes to the code to make life easier when compiling it
63        as part of something else:
65        (a) Change DEBUG to PCRE_DEBUG.
67        (b) In pcre_compile(), rename the member of the "branch_chain" structure
68            called "current" as "current_branch", to prevent a collision with the
69            Linux macro when compiled as a kernel module.
71        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
72            prevent a collision with the Linux macro when compiled as a kernel
73            module.
75    8.  In pcre_compile() there are some checks for integer overflows that used to
76        cast potentially large values to (double). This has been changed to that
77        when building, a check for int64_t is made, and if it is found, it is used
78        instead, thus avoiding the use of floating point arithmetic. (There is no
79        other use of FP in PCRE.) If int64_t is not found, the fallback is to
80        double.
82    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
83        2005 (difference between two addresses compared to an unsigned value).
85    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
86        custom one, because of the following reported problem in Windows:
88          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
89              under Win32.
90          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
91              therefore missing the function definition.
92          - The compiler thus generates a "C" signature for the test function.
93          - The linker fails to find the "C" function.
94          - PCRE fails to configure if asked to do so against libbz2.
96    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
97        messages were output:
99          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
100          rerunning libtoolize, to keep the correct libtool macros in-tree.
101          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
103        I have done both of these things.
105    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
106        most of the time, it *can* run out if it is given a pattern that contains a
107        runaway infinite recursion. I updated the discussion in the pcrestack man
108        page.
110    13. Now that we have gone to the x.xx style of version numbers, the minor
111        version may start with zero. Using 08 or 09 is a bad idea because users
112        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
113        interpreted as invalid octal numbers. I've updated the previous comment in
114        configure.ac, and also added a check that gives an error if 08 or 09 are
115        used.
117    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
118        causing partial matching to fail when the end of the subject matched \W
119        in a UTF-8 pattern where \W was quantified with a minimum of 3.
121    15. There were some discrepancies between the declarations in pcre_internal.h
122        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
123        their definitions. The declarations used "const uschar *" and the
124        definitions used USPTR. Even though USPTR is normally defined as "const
125        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
126        reported that: "This difference in casting confuses some C++ compilers, for
127        example, SunCC recognizes above declarations as different functions and
128        generates broken code for hbpcre." I have changed the declarations to use
129        USPTR.
131    16. GNU libtool is named differently on some systems. The autogen.sh script now
132        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
133        (FreeBSD).
135    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
136        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
137        comment: "Figure out how to create a longlong from a string: strtoll and
138        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
139        instance, but it only takes 2 args instead of 3!"
141    18. A subtle bug concerned with back references has been fixed by a change of
142        specification, with a corresponding code fix. A pattern such as
143        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
144        refers, was giving matches when it shouldn't. For example, xa=xaaa would
145        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
146        same bug. Such groups have to be quantified to be useful, or contained
147        inside another quantified group. (If there's no repetition, the reference
148        can never match.) The problem arises because, having left the group and
149        moved on to the rest of the pattern, a later failure that backtracks into
150        the group uses the captured value from the final iteration of the group
151        rather than the correct earlier one. I have fixed this in PCRE by forcing
152        any group that contains a reference to itself to be an atomic group; that
153        is, there cannot be any backtracking into it once it has completed. This is
154        similar to recursive and subroutine calls.
157    Version 8.00 19-Oct-09
158    ----------------------
160    1.  The table for translating pcre_compile() error codes into POSIX error codes
161        was out-of-date, and there was no check on the pcre_compile() error code
162        being within the table. This could lead to an OK return being given in
163        error.
165    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
166        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
167        in a Windows environment.
169    3.  The pcregrep --count option prints the count for each file even when it is
170        zero, as does GNU grep. However, pcregrep was also printing all files when
171        --files-with-matches was added. Now, when both options are given, it prints
172        counts only for those files that have at least one match. (GNU grep just
173        prints the file name in this circumstance, but including the count seems
174        more useful - otherwise, why use --count?) Also ensured that the
175        combination -clh just lists non-zero counts, with no names.
177    4.  The long form of the pcregrep -F option was incorrectly implemented as
178        --fixed_strings instead of --fixed-strings. This is an incompatible change,
179        but it seems right to fix it, and I didn't think it was worth preserving
180        the old behaviour.
182    5.  The command line items --regex=pattern and --regexp=pattern were not
183        recognized by pcregrep, which required --regex pattern or --regexp pattern
184        (with a space rather than an '='). The man page documented the '=' forms,
185        which are compatible with GNU grep; these now work.
187    6.  No libpcreposix.pc file was created for pkg-config; there was just
188        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
190    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
191        when UCP support is not needed, by modifying the Python script that
192        generates it from Unicode data files. This should not matter if the module
193        is correctly used as a library, but I received one complaint about 50K of
194        unwanted data. My guess is that the person linked everything into his
195        program rather than using a library. Anyway, it does no harm.
197    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
198        was a minimum greater than 1 for a wide character in a possessive
199        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
200        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
201        character. Chaos in the form of incorrect output or a compiling loop could
202        result.
204    9.  The restrictions on what a pattern can contain when partial matching is
205        requested for pcre_exec() have been removed. All patterns can now be
206        partially matched by this function. In addition, if there are at least two
207        slots in the offset vector, the offset of the earliest inspected character
208        for the match and the offset of the end of the subject are set in them when
209        PCRE_ERROR_PARTIAL is returned.
211    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
212        synonymous with PCRE_PARTIAL, for backwards compatibility, and
213        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
214        and may be more useful for multi-segment matching.
216    11. Partial matching with pcre_exec() is now more intuitive. A partial match
217        used to be given if ever the end of the subject was reached; now it is
218        given only if matching could not proceed because another character was
219        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
220        string "Z", which now yields "no match" instead of "partial match". In the
221        case of pcre_dfa_exec(), "no match" is given if every matching path for the
222        final character ended with (*FAIL).
224    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
225        if the pattern had a "must contain" character that was already found in the
226        earlier partial match, unless partial matching was again requested. For
227        example, with the pattern /dog.(body)?/, the "must contain" character is
228        "g". If the first part-match was for the string "dog", restarting with
229        "sbody" failed. This bug has been fixed.
231    13. The string returned by pcre_dfa_exec() after a partial match has been
232        changed so that it starts at the first inspected character rather than the
233        first character of the match. This makes a difference only if the pattern
234        starts with a lookbehind assertion or \b or \B (\K is not supported by
235        pcre_dfa_exec()). It's an incompatible change, but it makes the two
236        matching functions compatible, and I think it's the right thing to do.
238    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
239        so that the demonstration program is easily available in environments where
240        PCRE has not been installed from source.
242    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
243        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
244        library.
246    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
247        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
248        is not the first non-POSIX option to be added. Clearly some people find
249        these options useful.
251    17. If a caller to the POSIX matching function regexec() passes a non-zero
252        value for nmatch with a NULL value for pmatch, the value of
253        nmatch is forced to zero.
255    18. RunGrepTest did not have a test for the availability of the -u option of
256        the diff command, as RunTest does. It now checks in the same way as
257        RunTest, and also checks for the -b option.
259    19. If an odd number of negated classes containing just a single character
260        interposed, within parentheses, between a forward reference to a named
261        subpattern and the definition of the subpattern, compilation crashed with
262        an internal error, complaining that it could not find the referenced
263        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
264        [The bug was that it was starting one character too far in when skipping
265        over the character class, thus treating the ] as data rather than
266        terminating the class. This meant it could skip too much.]
268    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
269        /g option in pcretest when the pattern contains \K, which makes it possible
270        to have an empty string match not at the start, even when the pattern is
271        anchored. Updated pcretest and pcredemo to use this option.
273    21. If the maximum number of capturing subpatterns in a recursion was greater
274        than the maximum at the outer level, the higher number was returned, but
275        with unset values at the outer level. The correct (outer level) value is
276        now given.
278    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
279        PCRE did not set those parentheses (unlike Perl). I have now found a way to
280        make it do so. The string so far is captured, making this feature
281        compatible with Perl.
283    23. The tests have been re-organized, adding tests 11 and 12, to make it
284        possible to check the Perl 5.10 features against Perl 5.10.
286    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
287        pattern matches a fixed length string. PCRE did not allow this; now it
288        does. Neither allows recursion.
290    25. I finally figured out how to implement a request to provide the minimum
291        length of subject string that was needed in order to match a given pattern.
292        (It was back references and recursion that I had previously got hung up
293        on.) This code has now been added to pcre_study(); it finds a lower bound
294        to the length of subject needed. It is not necessarily the greatest lower
295        bound, but using it to avoid searching strings that are too short does give
296        some useful speed-ups. The value is available to calling programs via
297        pcre_fullinfo().
299    26. While implementing 25, I discovered to my embarrassment that pcretest had
300        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
301        study optimizations had never been tested with that matching function.
302        Oops. What is worse, even when it was passed study data, there was a bug in
303        pcre_dfa_exec() that meant it never actually used it. Double oops. There
304        were also very few tests of studied patterns with pcre_dfa_exec().
306    27. If (?| is used to create subpatterns with duplicate numbers, they are now
307        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
308        on the other side of the coin, they are no longer allowed to have different
309        names, because these cannot be distinguished in PCRE, and this has caused
310        confusion. (This is a difference from Perl.)
312    28. When duplicate subpattern names are present (necessarily with different
313        numbers, as required by 27 above), and a test is made by name in a
314        conditional pattern, either for a subpattern having been matched, or for
315        recursion in such a pattern, all the associated numbered subpatterns are
316        tested, and the overall condition is true if the condition is true for any
317        one of them. This is the way Perl works, and is also more like the way
318        testing by number works.
321    Version 7.9 11-Apr-09
322    ---------------------
324    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
325        (pcretest), all targets were linked against these libraries. This included
326        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
327        libraries. This caused unwanted dependencies to be created. This problem
328        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
329        pcretest is linked with readline.
331    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
332        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
333        moved outside it again, because FALSE and TRUE are already defined in AIX,
334        but BOOL is not.
336    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
337        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
339    4.  The pcregrep documentation said spaces were inserted as well as colons (or
340        hyphens) following file names and line numbers when outputting matching
341        lines. This is not true; no spaces are inserted. I have also clarified the
342        wording for the --colour (or --color) option.
344    5.  In pcregrep, when --colour was used with -o, the list of matching strings
345        was not coloured; this is different to GNU grep, so I have changed it to be
346        the same.
348    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
349        each matching line was coloured. Now it goes on to look for further matches
350        of any of the test patterns, which is the same behaviour as GNU grep.
352    7.  A pattern that could match an empty string could cause pcregrep to loop; it
353        doesn't make sense to accept an empty string match in pcregrep, so I have
354        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
355        seems to be how GNU grep behaves.
357    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
358        start or after a newline", because the conditional assertion was not being
359        correctly handled. The rule now is that both the assertion and what follows
360        in the first alternative must satisfy the test.
362    9.  If auto-callout was enabled in a pattern with a conditional group whose
363        condition was an assertion, PCRE could crash during matching, both with
364        pcre_exec() and pcre_dfa_exec().
366    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
367        used for matching.
369    11. Unicode property support in character classes was not working for
370        characters (bytes) greater than 127 when not in UTF-8 mode.
372    12. Added the -M command line option to pcretest.
374    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
376    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
378    16. Added comments and documentation about mis-use of no_arg in the C++
379        wrapper.
381    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
382        from Martin Jerabek that uses macro names for all relevant character and
383        string constants.
385    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
386        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
387        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
388        these, but not everybody uses configure.
390    19. A conditional group that had only one branch was not being correctly
391        recognized as an item that could match an empty string. This meant that an
392        enclosing group might also not be so recognized, causing infinite looping
393        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
394        with the subject "ab", where knowledge that the repeated group can match
395        nothing is needed in order to break the loop.
397    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
398        exec(), but without supplying a callout function, matching went wrong.
400    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
401        leak if the size of the offset vector was greater than 30. When the vector
402        is smaller, the saved offsets during recursion go onto a local stack
403        vector, but for larger vectors malloc() is used. It was failing to free
404        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
405        error, in fact).
407    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
408        heapframe that is used only when UTF-8 support is enabled. This caused no
409        problem, but was untidy.
411    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
412        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
413        included within another project.
415    24. Steven Van Ingelgem's patches to add more options to the CMake support,
416        slightly modified by me:
418          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
419              not building pcregrep.
421          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
422              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
424    25. Forward references, both numeric and by name, in patterns that made use of
425        duplicate group numbers, could behave incorrectly or give incorrect errors,
426        because when scanning forward to find the reference group, PCRE was not
427        taking into account the duplicate group numbers. A pattern such as
428        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
430    26. Changed a few more instances of "const unsigned char *" to USPTR, making
431        the feature of a custom pointer more persuasive (as requested by a user).
433    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
434        pcretest.c, inside #ifndefs, because it seems they are sometimes already
435        pre-defined.
437    28. Added support for (*UTF8) at the start of a pattern.
439    29. Arrange for flags added by the "release type" setting in CMake to be shown
440        in the configuration summary.
443    Version 7.8 05-Sep-08
444  ---------------------  ---------------------
446  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 452  Version 8.0 02 Jul-08
453  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
454      scripts.      scripts.
456  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
457      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,
458      or the function might crash, depending on the pattern.      or the function might crash, depending on the pattern.
460    4.  Caseless matching was not working for non-ASCII characters in back
461        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
462        It now works when Unicode Property Support is available.
464    5.  In pcretest, an escape such as \x{de} in the data was always generating
465        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
466        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
467        truncation.
469    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
471    7.  Added two (int) casts to pcregrep when printing the difference of two
472        pointers, in case they are 64-bit values.
474    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
475        test 2 if it fails.
477    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
478        and a #define of that name to empty if it is not externally set. This is to
479        allow users of MSVC to set it if necessary.
481    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
482        the convenience functions in the pcre_get.c source file.
484    11. An option change at the start of a pattern that had top-level alternatives
485        could cause overwriting and/or a crash. This command provoked a crash in
486        some environments:
488          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
490        This potential security problem was recorded as CVE-2008-2371.
492    12. For a pattern where the match had to start at the beginning or immediately
493        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
494        pcre_dfa_exec() could read past the end of the passed subject if there was
495        no match. To help with detecting such bugs (e.g. with valgrind), I modified
496        pcretest so that it places the subject at the end of its malloc-ed buffer.
498    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
499        exec() might read past the end of the data buffer in UTF-8 mode.
501    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
502        the data contained the byte 0x85 as part of a UTF-8 character within its
503        first line. This applied both to normal and DFA matching.
505    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
506        /^[^d]*?$/8 failed to match "abc".
508    16. Added a missing copyright notice to pcrecpp_internal.h.
510    17. Make it more clear in the documentation that values returned from
511        pcre_exec() in ovector are byte offsets, not character counts.
513    18. Tidied a few places to stop certain compilers from issuing warnings.
515    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
516        supplied by Stefan Weber. I made a further small update for 7.8 because
517        there is a change of source arrangements: the pcre_searchfuncs.c module is
518        replaced by pcre_ucd.c.
521  Version 7.7 07-May-08  Version 7.7 07-May-08

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