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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-07  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
31    Version 8.00 19-Oct-09
32    ----------------------
34    1.  The table for translating pcre_compile() error codes into POSIX error codes
35        was out-of-date, and there was no check on the pcre_compile() error code
36        being within the table. This could lead to an OK return being given in
37        error.
39    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
40        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
41        in a Windows environment.
43    3.  The pcregrep --count option prints the count for each file even when it is
44        zero, as does GNU grep. However, pcregrep was also printing all files when
45        --files-with-matches was added. Now, when both options are given, it prints
46        counts only for those files that have at least one match. (GNU grep just
47        prints the file name in this circumstance, but including the count seems
48        more useful - otherwise, why use --count?) Also ensured that the
49        combination -clh just lists non-zero counts, with no names.
51    4.  The long form of the pcregrep -F option was incorrectly implemented as
52        --fixed_strings instead of --fixed-strings. This is an incompatible change,
53        but it seems right to fix it, and I didn't think it was worth preserving
54        the old behaviour.
56    5.  The command line items --regex=pattern and --regexp=pattern were not
57        recognized by pcregrep, which required --regex pattern or --regexp pattern
58        (with a space rather than an '='). The man page documented the '=' forms,
59        which are compatible with GNU grep; these now work.
61    6.  No libpcreposix.pc file was created for pkg-config; there was just
62        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
64    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
65        when UCP support is not needed, by modifying the Python script that
66        generates it from Unicode data files. This should not matter if the module
67        is correctly used as a library, but I received one complaint about 50K of
68        unwanted data. My guess is that the person linked everything into his
69        program rather than using a library. Anyway, it does no harm.
71    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
72        was a minimum greater than 1 for a wide character in a possessive
73        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
74        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
75        character. Chaos in the form of incorrect output or a compiling loop could
76        result.
78    9.  The restrictions on what a pattern can contain when partial matching is
79        requested for pcre_exec() have been removed. All patterns can now be
80        partially matched by this function. In addition, if there are at least two
81        slots in the offset vector, the offset of the earliest inspected character
82        for the match and the offset of the end of the subject are set in them when
83        PCRE_ERROR_PARTIAL is returned.
85    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
86        synonymous with PCRE_PARTIAL, for backwards compatibility, and
87        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
88        and may be more useful for multi-segment matching.
90    11. Partial matching with pcre_exec() is now more intuitive. A partial match
91        used to be given if ever the end of the subject was reached; now it is
92        given only if matching could not proceed because another character was
93        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
94        string "Z", which now yields "no match" instead of "partial match". In the
95        case of pcre_dfa_exec(), "no match" is given if every matching path for the
96        final character ended with (*FAIL).
98    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
99        if the pattern had a "must contain" character that was already found in the
100        earlier partial match, unless partial matching was again requested. For
101        example, with the pattern /dog.(body)?/, the "must contain" character is
102        "g". If the first part-match was for the string "dog", restarting with
103        "sbody" failed. This bug has been fixed.
105    13. The string returned by pcre_dfa_exec() after a partial match has been
106        changed so that it starts at the first inspected character rather than the
107        first character of the match. This makes a difference only if the pattern
108        starts with a lookbehind assertion or \b or \B (\K is not supported by
109        pcre_dfa_exec()). It's an incompatible change, but it makes the two
110        matching functions compatible, and I think it's the right thing to do.
112    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
113        so that the demonstration program is easily available in environments where
114        PCRE has not been installed from source.
116    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
117        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
118        library.
120    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
121        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
122        is not the first non-POSIX option to be added. Clearly some people find
123        these options useful.
125    17. If a caller to the POSIX matching function regexec() passes a non-zero
126        value for nmatch with a NULL value for pmatch, the value of
127        nmatch is forced to zero.
129    18. RunGrepTest did not have a test for the availability of the -u option of
130        the diff command, as RunTest does. It now checks in the same way as
131        RunTest, and also checks for the -b option.
133    19. If an odd number of negated classes containing just a single character
134        interposed, within parentheses, between a forward reference to a named
135        subpattern and the definition of the subpattern, compilation crashed with
136        an internal error, complaining that it could not find the referenced
137        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
138        [The bug was that it was starting one character too far in when skipping
139        over the character class, thus treating the ] as data rather than
140        terminating the class. This meant it could skip too much.]
142    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
143        /g option in pcretest when the pattern contains \K, which makes it possible
144        to have an empty string match not at the start, even when the pattern is
145        anchored. Updated pcretest and pcredemo to use this option.
147    21. If the maximum number of capturing subpatterns in a recursion was greater
148        than the maximum at the outer level, the higher number was returned, but
149        with unset values at the outer level. The correct (outer level) value is
150        now given.
152    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
153        PCRE did not set those parentheses (unlike Perl). I have now found a way to
154        make it do so. The string so far is captured, making this feature
155        compatible with Perl.
157    23. The tests have been re-organized, adding tests 11 and 12, to make it
158        possible to check the Perl 5.10 features against Perl 5.10.
160    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
161        pattern matches a fixed length string. PCRE did not allow this; now it
162        does. Neither allows recursion.
164    25. I finally figured out how to implement a request to provide the minimum
165        length of subject string that was needed in order to match a given pattern.
166        (It was back references and recursion that I had previously got hung up
167        on.) This code has now been added to pcre_study(); it finds a lower bound
168        to the length of subject needed. It is not necessarily the greatest lower
169        bound, but using it to avoid searching strings that are too short does give
170        some useful speed-ups. The value is available to calling programs via
171        pcre_fullinfo().
173    26. While implementing 25, I discovered to my embarrassment that pcretest had
174        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
175        study optimizations had never been tested with that matching function.
176        Oops. What is worse, even when it was passed study data, there was a bug in
177        pcre_dfa_exec() that meant it never actually used it. Double oops. There
178        were also very few tests of studied patterns with pcre_dfa_exec().
180    27. If (?| is used to create subpatterns with duplicate numbers, they are now
181        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
182        on the other side of the coin, they are no longer allowed to have different
183        names, because these cannot be distinguished in PCRE, and this has caused
184        confusion. (This is a difference from Perl.)
186    28. When duplicate subpattern names are present (necessarily with different
187        numbers, as required by 27 above), and a test is made by name in a
188        conditional pattern, either for a subpattern having been matched, or for
189        recursion in such a pattern, all the associated numbered subpatterns are
190        tested, and the overall condition is true if the condition is true for any
191        one of them. This is the way Perl works, and is also more like the way
192        testing by number works.
195    Version 7.9 11-Apr-09
196    ---------------------
198    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
199        (pcretest), all targets were linked against these libraries. This included
200        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
201        libraries. This caused unwanted dependencies to be created. This problem
202        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
203        pcretest is linked with readline.
205    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
206        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
207        moved outside it again, because FALSE and TRUE are already defined in AIX,
208        but BOOL is not.
210    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
211        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
213    4.  The pcregrep documentation said spaces were inserted as well as colons (or
214        hyphens) following file names and line numbers when outputting matching
215        lines. This is not true; no spaces are inserted. I have also clarified the
216        wording for the --colour (or --color) option.
218    5.  In pcregrep, when --colour was used with -o, the list of matching strings
219        was not coloured; this is different to GNU grep, so I have changed it to be
220        the same.
222    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
223        each matching line was coloured. Now it goes on to look for further matches
224        of any of the test patterns, which is the same behaviour as GNU grep.
226    7.  A pattern that could match an empty string could cause pcregrep to loop; it
227        doesn't make sense to accept an empty string match in pcregrep, so I have
228        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
229        seems to be how GNU grep behaves.
231    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
232        start or after a newline", because the conditional assertion was not being
233        correctly handled. The rule now is that both the assertion and what follows
234        in the first alternative must satisfy the test.
236    9.  If auto-callout was enabled in a pattern with a conditional group whose
237        condition was an assertion, PCRE could crash during matching, both with
238        pcre_exec() and pcre_dfa_exec().
240    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
241        used for matching.
243    11. Unicode property support in character classes was not working for
244        characters (bytes) greater than 127 when not in UTF-8 mode.
246    12. Added the -M command line option to pcretest.
248    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
250    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
252    16. Added comments and documentation about mis-use of no_arg in the C++
253        wrapper.
255    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
256        from Martin Jerabek that uses macro names for all relevant character and
257        string constants.
259    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
260        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
261        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
262        these, but not everybody uses configure.
264    19. A conditional group that had only one branch was not being correctly
265        recognized as an item that could match an empty string. This meant that an
266        enclosing group might also not be so recognized, causing infinite looping
267        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
268        with the subject "ab", where knowledge that the repeated group can match
269        nothing is needed in order to break the loop.
271    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
272        exec(), but without supplying a callout function, matching went wrong.
274    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
275        leak if the size of the offset vector was greater than 30. When the vector
276        is smaller, the saved offsets during recursion go onto a local stack
277        vector, but for larger vectors malloc() is used. It was failing to free
278        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
279        error, in fact).
281    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
282        heapframe that is used only when UTF-8 support is enabled. This caused no
283        problem, but was untidy.
285    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
286        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
287        included within another project.
289    24. Steven Van Ingelgem's patches to add more options to the CMake support,
290        slightly modified by me:
292          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
293              not building pcregrep.
295          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
296              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
298    25. Forward references, both numeric and by name, in patterns that made use of
299        duplicate group numbers, could behave incorrectly or give incorrect errors,
300        because when scanning forward to find the reference group, PCRE was not
301        taking into account the duplicate group numbers. A pattern such as
302        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
304    26. Changed a few more instances of "const unsigned char *" to USPTR, making
305        the feature of a custom pointer more persuasive (as requested by a user).
307    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
308        pcretest.c, inside #ifndefs, because it seems they are sometimes already
309        pre-defined.
311    28. Added support for (*UTF8) at the start of a pattern.
313    29. Arrange for flags added by the "release type" setting in CMake to be shown
314        in the configuration summary.
317    Version 7.8 05-Sep-08
318    ---------------------
320    1.  Replaced UCP searching code with optimized version as implemented for Ad
321        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
322        stage table and inline lookup instead of a function, giving speed ups of 2
323        to 5 times on some simple patterns that I tested. Permission was given to
324        distribute the MultiStage2.py script that generates the tables (it's not in
325        the tarball, but is in the Subversion repository).
327    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
328        scripts.
330    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
331        a group with a zero qualifier. The result of the study could be incorrect,
332        or the function might crash, depending on the pattern.
334    4.  Caseless matching was not working for non-ASCII characters in back
335        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
336        It now works when Unicode Property Support is available.
338    5.  In pcretest, an escape such as \x{de} in the data was always generating
339        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
340        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
341        truncation.
343    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
345    7.  Added two (int) casts to pcregrep when printing the difference of two
346        pointers, in case they are 64-bit values.
348    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
349        test 2 if it fails.
351    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
352        and a #define of that name to empty if it is not externally set. This is to
353        allow users of MSVC to set it if necessary.
355    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
356        the convenience functions in the pcre_get.c source file.
358    11. An option change at the start of a pattern that had top-level alternatives
359        could cause overwriting and/or a crash. This command provoked a crash in
360        some environments:
362          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
364        This potential security problem was recorded as CVE-2008-2371.
366    12. For a pattern where the match had to start at the beginning or immediately
367        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
368        pcre_dfa_exec() could read past the end of the passed subject if there was
369        no match. To help with detecting such bugs (e.g. with valgrind), I modified
370        pcretest so that it places the subject at the end of its malloc-ed buffer.
372    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
373        exec() might read past the end of the data buffer in UTF-8 mode.
375    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
376        the data contained the byte 0x85 as part of a UTF-8 character within its
377        first line. This applied both to normal and DFA matching.
379    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
380        /^[^d]*?$/8 failed to match "abc".
382    16. Added a missing copyright notice to pcrecpp_internal.h.
384    17. Make it more clear in the documentation that values returned from
385        pcre_exec() in ovector are byte offsets, not character counts.
387    18. Tidied a few places to stop certain compilers from issuing warnings.
389    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
390        supplied by Stefan Weber. I made a further small update for 7.8 because
391        there is a change of source arrangements: the pcre_searchfuncs.c module is
392        replaced by pcre_ucd.c.
395    Version 7.7 07-May-08
396    ---------------------
398    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
399        a string to a long long, pretend we don't even have a long long." This is
400        done by checking for the strtoq, strtoll, and _strtoi64 functions.
402    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
403        pre-7.6 versions, which defined a global no_arg variable instead of putting
404        it in the RE class. (See also #8 below.)
406    3.  Remove a line of dead code, identified by coverity and reported by Nuno
407        Lopes.
409    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
411        (1) The include/exclude patterns were being applied to the whole pathnames
412            of files, instead of just to the final components.
414        (2) If there was more than one level of directory, the subdirectories were
415            skipped unless they satisfied the include/exclude conditions. This is
416            inconsistent with GNU grep (and could even be seen as contrary to the
417            pcregrep specification - which I improved to make it absolutely clear).
418            The action now is always to scan all levels of directory, and just
419            apply the include/exclude patterns to regular files.
421    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
422        --exclude_dir in the tests to avoid scanning .svn directories.
424    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
425        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
426        doesn't support NULs in patterns.
428    7.  Added some missing "const"s to declarations of static tables in
429        pcre_compile.c and pcre_dfa_exec.c.
431    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
432        caused by fix #2  above. (Subsequently also a second patch to fix the
433        first patch. And a third patch - this was a messy problem.)
435    9.  Applied Craig's patch to remove the use of push_back().
437    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
438        matching function regexec().
440    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
441        which, however, unlike Perl's \g{...}, are subroutine calls, not back
442        references. PCRE supports relative numbers with this syntax (I don't think
443        Oniguruma does).
445    12. Previously, a group with a zero repeat such as (...){0} was completely
446        omitted from the compiled regex. However, this means that if the group
447        was called as a subroutine from elsewhere in the pattern, things went wrong
448        (an internal error was given). Such groups are now left in the compiled
449        pattern, with a new opcode that causes them to be skipped at execution
450        time.
452    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
453        to the way PCRE behaves:
455        (a) A lone ] character is dis-allowed (Perl treats it as data).
457        (b) A back reference to an unmatched subpattern matches an empty string
458            (Perl fails the current match path).
460        (c) A data ] in a character class must be notated as \] because if the
461            first data character in a class is ], it defines an empty class. (In
462            Perl it is not possible to have an empty class.) The empty class []
463            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
464            The negative empty class [^] matches any one character, independently
465            of the DOTALL setting.
467    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
468        non-existent subpattern following a character class starting with ']' and
469        containing () gave an internal compiling error instead of "reference to
470        non-existent subpattern". Fortunately, when the pattern did exist, the
471        compiled code was correct. (When scanning forwards to check for the
472        existencd of the subpattern, it was treating the data ']' as terminating
473        the class, so got the count wrong. When actually compiling, the reference
474        was subsequently set up correctly.)
476    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
477        it was being rejected as not supported by pcre_dfa_exec(), even though
478        other assertions are supported. I have made pcre_dfa_exec() support
479        (*FAIL).
481    16. The implementation of 13c above involved the invention of a new opcode,
482        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
483        cannot be changed at match time, I realized I could make a small
484        improvement to matching performance by compiling OP_ALLANY instead of
485        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
486        on the OP_ANY path.
488    17. Compiling pcretest on Windows with readline support failed without the
489        following two fixes: (1) Make the unistd.h include conditional on
490        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
492    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
493        ncurses library to be included for pcretest when ReadLine support is
494        requested, but also to allow for it to be overridden. This patch came from
495        Daniel Bergström.
497    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
498        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
499        any errors with the current Unicode tables. Thanks to Peter Kankowski for
500        spotting this.
503    Version 7.6 28-Jan-08
504    ---------------------
506    1.  A character class containing a very large number of characters with
507        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
508        overflow.
510    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
511        HAVE_LONG_LONG is not defined.
513    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
514        bring them up to date and include new features. This patch includes:
516        - Fixed PH's badly added libz and libbz2 support.
517        - Fixed a problem with static linking.
518        - Added pcredemo. [But later removed - see 7 below.]
519        - Fixed dftables problem and added an option.
520        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
521            HAVE_LONG_LONG.
522        - Added readline support for pcretest.
523        - Added an listing of the option settings after cmake has run.
525    4.  A user submitted a patch to Makefile that makes it easy to create
526        "pcre.dll" under mingw when using Configure/Make. I added stuff to
527        Makefile.am that cause it to include this special target, without
528        affecting anything else. Note that the same mingw target plus all
529        the other distribution libraries and programs are now supported
530        when configuring with CMake (see 6 below) instead of with
531        Configure/Make.
533    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
534        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
535        exported in the Windows port". It has not yet been confirmed that the patch
536        solves the problem, but it does no harm.
538    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
539        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
540        with CMake, and also correct the comment about stack recursion.
542    7.  Remove the automatic building of pcredemo from the ./configure system and
543        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
544        of a program that users should build themselves after PCRE is installed, so
545        building it automatically is not really right. What is more, it gave
546        trouble in some build environments.
548    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
551    Version 7.5 10-Jan-08
552    ---------------------
554    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
555        values in parens when parsing an RE using the C++ wrapper."
557    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
558        Characters greater than 255 were excluded from the class instead of being
559        included.
561    3.  The same bug as (2) above applied to negated POSIX classes such as
562        [:^space:].
564    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
565        defined or documented. It seems to have been a typo for PCRE_STATIC, so
566        I have changed it.
568    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
569        first named subpattern) and a construct such as (?&a) would reference the
570        first named subpattern whose name started with "a" (in other words, the
571        length check was missing). Both these problems are fixed. "Subpattern name
572        expected" is now given for (?&) (a zero-length name), and this patch also
573        makes it give the same error for \k'' (previously it complained that that
574        was a reference to a non-existent subpattern).
576    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
577        this is right because (?- can be followed by option settings as well as by
578        digits. I have, however, made the messages clearer.
580    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
581        than the number used in the conditional) now cause a compile-time error.
582        This is actually not compatible with Perl, which accepts such patterns, but
583        treats the conditional as always being FALSE (as PCRE used to), but it
584        seems to me that giving a diagnostic is better.
586    8.  Change "alphameric" to the more common word "alphanumeric" in comments
587        and messages.
589    9.  Fix two occurrences of "backslash" in comments that should have been
590        "backspace".
592    10. Remove two redundant lines of code that can never be obeyed (their function
593        was moved elsewhere).
595    11. The program that makes PCRE's Unicode character property table had a bug
596        which caused it to generate incorrect table entries for sequences of
597        characters that have the same character type, but are in different scripts.
598        It amalgamated them into a single range, with the script of the first of
599        them. In other words, some characters were in the wrong script. There were
600        thirteen such cases, affecting characters in the following ranges:
602          U+002b0 - U+002c1
603          U+0060c - U+0060d
604          U+0061e - U+00612
605          U+0064b - U+0065e
606          U+0074d - U+0076d
607          U+01800 - U+01805
608          U+01d00 - U+01d77
609          U+01d9b - U+01dbf
610          U+0200b - U+0200f
611          U+030fc - U+030fe
612          U+03260 - U+0327f
613          U+0fb46 - U+0fbb1
614          U+10450 - U+1049d
616    12. The -o option (show only the matching part of a line) for pcregrep was not
617        compatible with GNU grep in that, if there was more than one match in a
618        line, it showed only the first of them. It now behaves in the same way as
619        GNU grep.
621    13. If the -o and -v options were combined for pcregrep, it printed a blank
622        line for every non-matching line. GNU grep prints nothing, and pcregrep now
623        does the same. The return code can be used to tell if there were any
624        non-matching lines.
626    14. Added --file-offsets and --line-offsets to pcregrep.
628    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
629        infinitely looping recursion. The bug was that positive lookaheads were not
630        being skipped when checking for a possible empty match (negative lookaheads
631        and both kinds of lookbehind were skipped).
633    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
634        inclusion of <windows.h> to before rather than after the definition of
635        INVALID_FILE_ATTRIBUTES (patch from David Byron).
637    17. Specifying a possessive quantifier with a specific limit for a Unicode
638        character property caused pcre_compile() to compile bad code, which led at
639        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
640        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
641        caused the error; without that there was no problem.
643    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
645    19. Added --enable-pcretest-libreadline.
647    20. In pcrecpp.cc, the variable 'count' was incremented twice in
648        RE::GlobalReplace(). As a result, the number of replacements returned was
649        double what it should be. I removed one of the increments, but Craig sent a
650        later patch that removed the other one (the right fix) and added unit tests
651        that check the return values (which was not done before).
653    21. Several CMake things:
655        (1) Arranged that, when cmake is used on Unix, the libraries end up with
656            the names libpcre and libpcreposix, not just pcre and pcreposix.
658        (2) The above change means that pcretest and pcregrep are now correctly
659            linked with the newly-built libraries, not previously installed ones.
663    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
664        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
665        UTF-8 newline character). The key issue is that the pattern starts .*;
666        this means that the match must be either at the beginning, or after a
667        newline. The bug was in the code for advancing after a failed match and
668        checking that the new position followed a newline. It was not taking
669        account of UTF-8 characters correctly.
671    23. PCRE was behaving differently from Perl in the way it recognized POSIX
672        character classes. PCRE was not treating the sequence [:...:] as a
673        character class unless the ... were all letters. Perl, however, seems to
674        allow any characters between [: and :], though of course it rejects as
675        unknown any "names" that contain non-letters, because all the known class
676        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
677        for example, whereas PCRE did not - it did not recognize a POSIX character
678        class. This seemed a bit dangerous, so the code has been changed to be
679        closer to Perl. The behaviour is not identical to Perl, because PCRE will
680        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
681        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
682        Perl does, and where it didn't before.
684    24. Rewrite so as to remove the single use of %n from pcregrep because in some
685        Windows environments %n is disabled by default.
688    Version 7.4 21-Sep-07
689    ---------------------
691    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
692        means that a class such as [\s] counted as "explicit reference to CR or
693        LF". That isn't really right - the whole point of the change was to try to
694        help when there was an actual mention of one of the two characters. So now
695        the change happens only if \r or \n (or a literal CR or LF) character is
696        encountered.
698    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
699        of both had grown to the point where there were only 3 bits left.
700        Fortunately, there was spare space in the data structure, and so I have
701        moved the internal flags into a new 16-bit field to free up more option
702        bits.
704    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
705        but did not set the internal JCHANGED flag - either of these is enough to
706        control the way the "get" function works - but the PCRE_INFO_JCHANGED
707        facility is supposed to tell if (?J) was ever used, so now (?J) at the
708        start sets both bits.
710    4.  Added options (at build time, compile time, exec time) to change \R from
711        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
713    5.  doc/pcresyntax.html was missing from the distribution.
715    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
716        compatibility, even though it is no longer used.
718    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
719        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
720        windows.h file is present (where different names are used). [This was
721        reversed later after testing - see 16 below.]
723    8.  Changed all #include <config.h> to #include "config.h". There were also
724        some further <pcre.h> cases that I changed to "pcre.h".
726    9.  When pcregrep was used with the --colour option, it missed the line ending
727        sequence off the lines that it output.
729    10. It was pointed out to me that arrays of string pointers cause lots of
730        relocations when a shared library is dynamically loaded. A technique of
731        using a single long string with a table of offsets can drastically reduce
732        these. I have refactored PCRE in four places to do this. The result is
733        dramatic:
735          Originally:                          290
736          After changing UCP table:            187
737          After changing error message table:   43
738          After changing table of "verbs"       36
739          After changing table of Posix names   22
741        Thanks to the folks working on Gregex for glib for this insight.
743    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
744        unicode-properties was also set.
746    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
748    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
749        checked only for CRLF.
751    14. Added casts to pcretest.c to avoid compiler warnings.
753    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
755    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
756        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
757        entirely. This removes changes made in 7 above.
759    17. The CMake files have been updated, and there is now more information about
760        building with CMake in the NON-UNIX-USE document.
763    Version 7.3 28-Aug-07
764    ---------------------
766     1. In the rejigging of the build system that eventually resulted in 7.1, the
767        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
768        brackets there is not right, since it causes compilers to look for an
769        installed pcre.h, not the version that is in the source that is being
770        compiled (which of course may be different). I have changed it back to:
772          #include "pcre.h"
774        I have a vague recollection that the change was concerned with compiling in
775        different directories, but in the new build system, that is taken care of
776        by the VPATH setting the Makefile.
778     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
779        when the subject happened to end in the byte 0x85 (e.g. if the last
780        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
781        characters but of course it shouldn't be taken as a newline when it is part
782        of another character. The bug was that, for an unlimited repeat of . in
783        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
784        characters when looking for a newline.
786     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
788     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
789        in debug output.
791     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
792        long printing in the pcrecpp unittest when running under MinGW.
794     6. ESC_K was left out of the EBCDIC table.
796     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
797        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
798        limit also applies to "virtual nesting" when a pattern is recursive, and in
799        this case 1000 isn't so big. I have been able to remove this limit at the
800        expense of backing off one optimization in certain circumstances. Normally,
801        when pcre_exec() would call its internal match() function recursively and
802        immediately return the result unconditionally, it uses a "tail recursion"
803        feature to save stack. However, when a subpattern that can match an empty
804        string has an unlimited repetition quantifier, it no longer makes this
805        optimization. That gives it a stack frame in which to save the data for
806        checking that an empty string has been matched. Previously this was taken
807        from the 1000-entry workspace that had been reserved. So now there is no
808        explicit limit, but more stack is used.
810     8. Applied Daniel's patches to solve problems with the import/export magic
811        syntax that is required for Windows, and which was going wrong for the
812        pcreposix and pcrecpp parts of the library. These were overlooked when this
813        problem was solved for the main library.
815     9. There were some crude static tests to avoid integer overflow when computing
816        the size of patterns that contain repeated groups with explicit upper
817        limits. As the maximum quantifier is 65535, the maximum group length was
818        set at 30,000 so that the product of these two numbers did not overflow a
819        32-bit integer. However, it turns out that people want to use groups that
820        are longer than 30,000 bytes (though not repeat them that many times).
821        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
822        made it possible to implement the integer overflow checks in a much more
823        dynamic way, which I have now done. The artificial limitation on group
824        length has been removed - we now have only the limit on the total length of
825        the compiled pattern, which depends on the LINK_SIZE setting.
827    10. Fixed a bug in the documentation for get/copy named substring when
828        duplicate names are permitted. If none of the named substrings are set, the
829        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
830        empty string.
832    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
833        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
834        because the ] is interpreted as the first data character and the
835        terminating ] is not found. PCRE has been made compatible with Perl in this
836        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
837        cause memory overwriting.
839    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
840        string has been matched (to stop an infinite loop). It was not recognizing
841        a conditional subpattern that could match an empty string if that
842        subpattern was within another subpattern. For example, it looped when
843        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
844        condition was not nested. This bug has been fixed.
846    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
847        past the start of the subject in the presence of bytes with the top bit
848        set, for example "\x8aBCD".
850    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
851        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
853    14. Optimized (?!) to (*FAIL).
855    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
856        This restricts code points to be within the range 0 to 0x10FFFF, excluding
857        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
858        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
859        does: it's just the validity check that is more restrictive.
861    16. Inserted checks for integer overflows during escape sequence (backslash)
862        processing, and also fixed erroneous offset values for syntax errors during
863        backslash processing.
865    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
866        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
868    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
869        caused an overrun.
871    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
872        something other than just ASCII characters) inside a group that had an
873        unlimited repeat caused a loop at compile time (while checking to see
874        whether the group could match an empty string).
876    20. Debugging a pattern containing \p or \P could cause a crash. For example,
877        [\P{Any}] did so. (Error in the code for printing property names.)
879    21. An orphan \E inside a character class could cause a crash.
881    22. A repeated capturing bracket such as (A)? could cause a wild memory
882        reference during compilation.
884    23. There are several functions in pcre_compile() that scan along a compiled
885        expression for various reasons (e.g. to see if it's fixed length for look
886        behind). There were bugs in these functions when a repeated \p or \P was
887        present in the pattern. These operators have additional parameters compared
888        with \d, etc, and these were not being taken into account when moving along
889        the compiled data. Specifically:
891        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
892            length.
894        (b) An item such as \pL+ within a repeated group could cause crashes or
895            loops.
897        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
898            "reference to non-existent subpattern" error.
900        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
902    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
903        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
905    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
907    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
908        character were causing crashes (broken optimization).
910    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
911        \p or \P) caused a compile-time loop.
913    28. More problems have arisen in unanchored patterns when CRLF is a valid line
914        break. For example, the unstudied pattern [\r\n]A does not match the string
915        "\r\nA" because change 7.0/46 below moves the current point on by two
916        characters after failing to match at the start. However, the pattern \nA
917        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
918        the same is true. There doesn't seem any very clean way out of this, but
919        what I have chosen to do makes the common cases work: PCRE now takes note
920        of whether there can be an explicit match for \r or \n anywhere in the
921        pattern, and if so, 7.0/46 no longer applies. As part of this change,
922        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
923        pattern has explicit CR or LF references.
925    29. Added (*CR) etc for changing newline setting at start of pattern.
928    Version 7.2 19-Jun-07
929  ---------------------  ---------------------
931   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 11  Version 7.2 01-May-07 Line 935  Version 7.2 01-May-07
935      to make them independent of the local environment's newline setting.      to make them independent of the local environment's newline setting.
937   3. Add code to configure.ac to remove -g from the CFLAGS default settings.   3. Add code to configure.ac to remove -g from the CFLAGS default settings.
939   4. Some of the "internals" tests were previously cut out when the link size   4. Some of the "internals" tests were previously cut out when the link size
940      was not 2, because the output contained actual offsets. The recent new      was not 2, because the output contained actual offsets. The recent new
941      "Z" feature of pcretest means that these can be cut out, making the tests      "Z" feature of pcretest means that these can be cut out, making the tests
942      usable with all link sizes.      usable with all link sizes.
944     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
945        stack recursion. This gives a massive performance boost under BSD, but just
946        a small improvement under Linux. However, it saves one field in the frame
947        in all cases.
949     6. Added more features from the forthcoming Perl 5.10:
951        (a) (?-n) (where n is a string of digits) is a relative subroutine or
952            recursion call. It refers to the nth most recently opened parentheses.
954        (b) (?+n) is also a relative subroutine call; it refers to the nth next
955            to be opened parentheses.
957        (c) Conditions that refer to capturing parentheses can be specified
958            relatively, for example, (?(-2)... or (?(+3)...
960        (d) \K resets the start of the current match so that everything before
961            is not part of it.
963        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
965        (f) \g{name} is another synonym - part of Perl 5.10's unification of
966            reference syntax.
968        (g) (?| introduces a group in which the numbering of parentheses in each
969            alternative starts with the same number.
971        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
973     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
976     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
977        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
978        for detecting groups that can match an empty string.
980     9. A pattern with a very large number of alternatives (more than several
981        hundred) was running out of internal workspace during the pre-compile
982        phase, where pcre_compile() figures out how much memory will be needed. A
983        bit of new cunning has reduced the workspace needed for groups with
984        alternatives. The 1000-alternative test pattern now uses 12 bytes of
985        workspace instead of running out of the 4096 that are available.
987    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
989    11. Applied patch from Google to remove an optimization that didn't quite work.
990        The report of the bug said:
992          pcrecpp::RE("a*").FullMatch("aaa") matches, while
993          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
994          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
996    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
997        it matched the wrong number of bytes.
1000  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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