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revision 79 by nigel, Sat Feb 24 21:40:52 2007 UTC revision 459 by ph10, Sun Oct 4 09:21:39 2009 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.00 ??-???-??
5    ----------------------
6    
7    1.  The table for translating pcre_compile() error codes into POSIX error codes
8        was out-of-date, and there was no check on the pcre_compile() error code
9        being within the table. This could lead to an OK return being given in
10        error.
11    
12    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
13        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14        in a Windows environment.
15    
16    3.  The pcregrep --count option prints the count for each file even when it is
17        zero, as does GNU grep. However, pcregrep was also printing all files when
18        --files-with-matches was added. Now, when both options are given, it prints
19        counts only for those files that have at least one match. (GNU grep just
20        prints the file name in this circumstance, but including the count seems
21        more useful - otherwise, why use --count?) Also ensured that the
22        combination -clh just lists non-zero counts, with no names.
23    
24    4.  The long form of the pcregrep -F option was incorrectly implemented as
25        --fixed_strings instead of --fixed-strings. This is an incompatible change,
26        but it seems right to fix it, and I didn't think it was worth preserving
27        the old behaviour.
28    
29    5.  The command line items --regex=pattern and --regexp=pattern were not
30        recognized by pcregrep, which required --regex pattern or --regexp pattern
31        (with a space rather than an '='). The man page documented the '=' forms,
32        which are compatible with GNU grep; these now work.
33    
34    6.  No libpcreposix.pc file was created for pkg-config; there was just
35        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
36    
37    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38        when UCP support is not needed, by modifying the Python script that
39        generates it from Unicode data files. This should not matter if the module
40        is correctly used as a library, but I received one complaint about 50K of
41        unwanted data. My guess is that the person linked everything into his
42        program rather than using a library. Anyway, it does no harm.
43    
44    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45        was a minimum greater than 1 for a wide character in a possessive
46        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48        character. Chaos in the form of incorrect output or a compiling loop could
49        result.
50    
51    9.  The restrictions on what a pattern can contain when partial matching is
52        requested for pcre_exec() have been removed. All patterns can now be
53        partially matched by this function. In addition, if there are at least two
54        slots in the offset vector, the offset of the earliest inspected character
55        for the match and the offset of the end of the subject are set in them when
56        PCRE_ERROR_PARTIAL is returned.
57    
58    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59        synonymous with PCRE_PARTIAL, for backwards compatibility, and
60        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61        and may be more useful for multi-segment matching, especially with
62        pcre_exec().
63    
64    11. Partial matching with pcre_exec() is now more intuitive. A partial match
65        used to be given if ever the end of the subject was reached; now it is
66        given only if matching could not proceed because another character was
67        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68        string "Z", which now yields "no match" instead of "partial match". In the
69        case of pcre_dfa_exec(), "no match" is given if every matching path for the
70        final character ended with (*FAIL).
71    
72    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73        if the pattern had a "must contain" character that was already found in the
74        earlier partial match, unless partial matching was again requested. For
75        example, with the pattern /dog.(body)?/, the "must contain" character is
76        "g". If the first part-match was for the string "dog", restarting with
77        "sbody" failed. This bug has been fixed.
78    
79    13. The string returned by pcre_dfa_exec() after a partial match has been
80        changed so that it starts at the first inspected character rather than the
81        first character of the match. This makes a difference only if the pattern
82        starts with a lookbehind assertion or \b or \B (\K is not supported by
83        pcre_dfa_exec()). It's an incompatible change, but it makes the two
84        matching functions compatible, and I think it's the right thing to do.
85    
86    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87        so that the demonstration program is easily available in environments where
88        PCRE has not been installed from source.
89    
90    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92        library.
93    
94    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96        is not the first non-POSIX option to be added. Clearly some people find
97        these options useful.
98    
99    17. If a caller to the POSIX matching function regexec() passes a non-zero
100        value for nmatch with a NULL value for pmatch, the value of
101        nmatch is forced to zero.
102    
103    18. RunGrepTest did not have a test for the availability of the -u option of
104        the diff command, as RunTest does. It now checks in the same way as
105        RunTest, and also checks for the -b option.
106    
107    19. If an odd number of negated classes containing just a single character
108        interposed, within parentheses, between a forward reference to a named
109        subpattern and the definition of the subpattern, compilation crashed with
110        an internal error, complaining that it could not find the referenced
111        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112        [The bug was that it was starting one character too far in when skipping
113        over the character class, thus treating the ] as data rather than
114        terminating the class. This meant it could skip too much.]
115    
116    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
117        /g option in pcretest when the pattern contains \K, which makes it possible
118        to have an empty string match not at the start, even when the pattern is
119        anchored. Updated pcretest and pcredemo to use this option.
120    
121    21. If the maximum number of capturing subpatterns in a recursion was greater
122        than the maximum at the outer level, the higher number was returned, but
123        with unset values at the outer level. The correct (outer level) value is
124        now given.
125    
126    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
127        PCRE did not set those parentheses (unlike Perl). I have now found a way to
128        make it do so. The string so far is captured, making this feature
129        compatible with Perl.
130    
131    23. The tests have been re-organized, adding tests 11 and 12, to make it
132        possible to check the Perl 5.10 features against Perl 5.10.
133    
134    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
135        pattern matches a fixed length string. PCRE did not allow this; now it
136        does. Neither allows recursion.
137    
138    25. I finally figured out how to implement a request to provide the minimum
139        length of subject string that was needed in order to match a given pattern.
140        (It was back references and recursion that I had previously got hung up
141        on.) This code has now been added to pcre_study(); it finds a lower bound
142        to the length of subject needed. It is not necessarily the greatest lower
143        bound, but using it to avoid searching strings that are too short does give
144        some useful speed-ups. The value is available to calling programs via
145        pcre_fullinfo().
146    
147    26. While implementing 25, I discovered to my embarrassment that pcretest had
148        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
149        study optimizations had never been tested with that matching function.
150        Oops. What is worse, even when it was passed study data, there was a bug in
151        pcre_dfa_exec() that meant it never actually used it. Double oops. There
152        were also very few tests of studied patterns with pcre_dfa_exec().
153    
154    27. If (?| is used to create subpatterns with duplicate numbers, they are now
155        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
156        on the other side of the coin, they are no longer allowed to have different
157        names, because these cannot be distinguished in PCRE, and this has caused
158        confusion. (This is a difference from Perl.)
159    
160    28. When duplicate subpattern names are present (necessarily with different
161        numbers, as required by 27 above), and a test is made by name in a
162        conditional pattern, either for a subpattern having been matched, or for
163        recursion in such a pattern, all the associated numbered subpatterns are
164        tested, and the overall condition is true if the condition is true for any
165        one of them. This is the way Perl works, and is also more like the way
166        testing by number works.
167    
168    
169    Version 7.9 11-Apr-09
170    ---------------------
171    
172    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
173        (pcretest), all targets were linked against these libraries. This included
174        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
175        libraries. This caused unwanted dependencies to be created. This problem
176        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
177        pcretest is linked with readline.
178    
179    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
180        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
181        moved outside it again, because FALSE and TRUE are already defined in AIX,
182        but BOOL is not.
183    
184    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
185        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
186    
187    4.  The pcregrep documentation said spaces were inserted as well as colons (or
188        hyphens) following file names and line numbers when outputting matching
189        lines. This is not true; no spaces are inserted. I have also clarified the
190        wording for the --colour (or --color) option.
191    
192    5.  In pcregrep, when --colour was used with -o, the list of matching strings
193        was not coloured; this is different to GNU grep, so I have changed it to be
194        the same.
195    
196    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
197        each matching line was coloured. Now it goes on to look for further matches
198        of any of the test patterns, which is the same behaviour as GNU grep.
199    
200    7.  A pattern that could match an empty string could cause pcregrep to loop; it
201        doesn't make sense to accept an empty string match in pcregrep, so I have
202        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
203        seems to be how GNU grep behaves.
204    
205    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
206        start or after a newline", because the conditional assertion was not being
207        correctly handled. The rule now is that both the assertion and what follows
208        in the first alternative must satisfy the test.
209    
210    9.  If auto-callout was enabled in a pattern with a conditional group whose
211        condition was an assertion, PCRE could crash during matching, both with
212        pcre_exec() and pcre_dfa_exec().
213    
214    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
215        used for matching.
216    
217    11. Unicode property support in character classes was not working for
218        characters (bytes) greater than 127 when not in UTF-8 mode.
219    
220    12. Added the -M command line option to pcretest.
221    
222    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
223    
224    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
225    
226    16. Added comments and documentation about mis-use of no_arg in the C++
227        wrapper.
228    
229    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
230        from Martin Jerabek that uses macro names for all relevant character and
231        string constants.
232    
233    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
234        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
235        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
236        these, but not everybody uses configure.
237    
238    19. A conditional group that had only one branch was not being correctly
239        recognized as an item that could match an empty string. This meant that an
240        enclosing group might also not be so recognized, causing infinite looping
241        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
242        with the subject "ab", where knowledge that the repeated group can match
243        nothing is needed in order to break the loop.
244    
245    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
246        exec(), but without supplying a callout function, matching went wrong.
247    
248    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
249        leak if the size of the offset vector was greater than 30. When the vector
250        is smaller, the saved offsets during recursion go onto a local stack
251        vector, but for larger vectors malloc() is used. It was failing to free
252        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
253        error, in fact).
254    
255    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
256        heapframe that is used only when UTF-8 support is enabled. This caused no
257        problem, but was untidy.
258    
259    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
260        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
261        included within another project.
262    
263    24. Steven Van Ingelgem's patches to add more options to the CMake support,
264        slightly modified by me:
265    
266          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
267              not building pcregrep.
268    
269          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
270              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
271    
272    25. Forward references, both numeric and by name, in patterns that made use of
273        duplicate group numbers, could behave incorrectly or give incorrect errors,
274        because when scanning forward to find the reference group, PCRE was not
275        taking into account the duplicate group numbers. A pattern such as
276        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
277    
278    26. Changed a few more instances of "const unsigned char *" to USPTR, making
279        the feature of a custom pointer more persuasive (as requested by a user).
280    
281    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
282        pcretest.c, inside #ifndefs, because it seems they are sometimes already
283        pre-defined.
284    
285    28. Added support for (*UTF8) at the start of a pattern.
286    
287    29. Arrange for flags added by the "release type" setting in CMake to be shown
288        in the configuration summary.
289    
290    
291    Version 7.8 05-Sep-08
292    ---------------------
293    
294    1.  Replaced UCP searching code with optimized version as implemented for Ad
295        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
296        stage table and inline lookup instead of a function, giving speed ups of 2
297        to 5 times on some simple patterns that I tested. Permission was given to
298        distribute the MultiStage2.py script that generates the tables (it's not in
299        the tarball, but is in the Subversion repository).
300    
301    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
302        scripts.
303    
304    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
305        a group with a zero qualifier. The result of the study could be incorrect,
306        or the function might crash, depending on the pattern.
307    
308    4.  Caseless matching was not working for non-ASCII characters in back
309        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
310        It now works when Unicode Property Support is available.
311    
312    5.  In pcretest, an escape such as \x{de} in the data was always generating
313        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
314        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
315        truncation.
316    
317    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
318    
319    7.  Added two (int) casts to pcregrep when printing the difference of two
320        pointers, in case they are 64-bit values.
321    
322    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
323        test 2 if it fails.
324    
325    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
326        and a #define of that name to empty if it is not externally set. This is to
327        allow users of MSVC to set it if necessary.
328    
329    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
330        the convenience functions in the pcre_get.c source file.
331    
332    11. An option change at the start of a pattern that had top-level alternatives
333        could cause overwriting and/or a crash. This command provoked a crash in
334        some environments:
335    
336          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
337    
338        This potential security problem was recorded as CVE-2008-2371.
339    
340    12. For a pattern where the match had to start at the beginning or immediately
341        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
342        pcre_dfa_exec() could read past the end of the passed subject if there was
343        no match. To help with detecting such bugs (e.g. with valgrind), I modified
344        pcretest so that it places the subject at the end of its malloc-ed buffer.
345    
346    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
347        exec() might read past the end of the data buffer in UTF-8 mode.
348    
349    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
350        the data contained the byte 0x85 as part of a UTF-8 character within its
351        first line. This applied both to normal and DFA matching.
352    
353    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
354        /^[^d]*?$/8 failed to match "abc".
355    
356    16. Added a missing copyright notice to pcrecpp_internal.h.
357    
358    17. Make it more clear in the documentation that values returned from
359        pcre_exec() in ovector are byte offsets, not character counts.
360    
361    18. Tidied a few places to stop certain compilers from issuing warnings.
362    
363    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
364        supplied by Stefan Weber. I made a further small update for 7.8 because
365        there is a change of source arrangements: the pcre_searchfuncs.c module is
366        replaced by pcre_ucd.c.
367    
368    
369    Version 7.7 07-May-08
370    ---------------------
371    
372    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
373        a string to a long long, pretend we don't even have a long long." This is
374        done by checking for the strtoq, strtoll, and _strtoi64 functions.
375    
376    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
377        pre-7.6 versions, which defined a global no_arg variable instead of putting
378        it in the RE class. (See also #8 below.)
379    
380    3.  Remove a line of dead code, identified by coverity and reported by Nuno
381        Lopes.
382    
383    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
384    
385        (1) The include/exclude patterns were being applied to the whole pathnames
386            of files, instead of just to the final components.
387    
388        (2) If there was more than one level of directory, the subdirectories were
389            skipped unless they satisfied the include/exclude conditions. This is
390            inconsistent with GNU grep (and could even be seen as contrary to the
391            pcregrep specification - which I improved to make it absolutely clear).
392            The action now is always to scan all levels of directory, and just
393            apply the include/exclude patterns to regular files.
394    
395    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
396        --exclude_dir in the tests to avoid scanning .svn directories.
397    
398    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
399        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
400        doesn't support NULs in patterns.
401    
402    7.  Added some missing "const"s to declarations of static tables in
403        pcre_compile.c and pcre_dfa_exec.c.
404    
405    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
406        caused by fix #2  above. (Subsequently also a second patch to fix the
407        first patch. And a third patch - this was a messy problem.)
408    
409    9.  Applied Craig's patch to remove the use of push_back().
410    
411    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
412        matching function regexec().
413    
414    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
415        which, however, unlike Perl's \g{...}, are subroutine calls, not back
416        references. PCRE supports relative numbers with this syntax (I don't think
417        Oniguruma does).
418    
419    12. Previously, a group with a zero repeat such as (...){0} was completely
420        omitted from the compiled regex. However, this means that if the group
421        was called as a subroutine from elsewhere in the pattern, things went wrong
422        (an internal error was given). Such groups are now left in the compiled
423        pattern, with a new opcode that causes them to be skipped at execution
424        time.
425    
426    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
427        to the way PCRE behaves:
428    
429        (a) A lone ] character is dis-allowed (Perl treats it as data).
430    
431        (b) A back reference to an unmatched subpattern matches an empty string
432            (Perl fails the current match path).
433    
434        (c) A data ] in a character class must be notated as \] because if the
435            first data character in a class is ], it defines an empty class. (In
436            Perl it is not possible to have an empty class.) The empty class []
437            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
438            The negative empty class [^] matches any one character, independently
439            of the DOTALL setting.
440    
441    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
442        non-existent subpattern following a character class starting with ']' and
443        containing () gave an internal compiling error instead of "reference to
444        non-existent subpattern". Fortunately, when the pattern did exist, the
445        compiled code was correct. (When scanning forwards to check for the
446        existencd of the subpattern, it was treating the data ']' as terminating
447        the class, so got the count wrong. When actually compiling, the reference
448        was subsequently set up correctly.)
449    
450    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
451        it was being rejected as not supported by pcre_dfa_exec(), even though
452        other assertions are supported. I have made pcre_dfa_exec() support
453        (*FAIL).
454    
455    16. The implementation of 13c above involved the invention of a new opcode,
456        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
457        cannot be changed at match time, I realized I could make a small
458        improvement to matching performance by compiling OP_ALLANY instead of
459        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
460        on the OP_ANY path.
461    
462    17. Compiling pcretest on Windows with readline support failed without the
463        following two fixes: (1) Make the unistd.h include conditional on
464        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
465    
466    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
467        ncurses library to be included for pcretest when ReadLine support is
468        requested, but also to allow for it to be overridden. This patch came from
469        Daniel Bergström.
470    
471    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
472        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
473        any errors with the current Unicode tables. Thanks to Peter Kankowski for
474        spotting this.
475    
476    
477    Version 7.6 28-Jan-08
478    ---------------------
479    
480    1.  A character class containing a very large number of characters with
481        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
482        overflow.
483    
484    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
485        HAVE_LONG_LONG is not defined.
486    
487    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
488        bring them up to date and include new features. This patch includes:
489    
490        - Fixed PH's badly added libz and libbz2 support.
491        - Fixed a problem with static linking.
492        - Added pcredemo. [But later removed - see 7 below.]
493        - Fixed dftables problem and added an option.
494        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
495            HAVE_LONG_LONG.
496        - Added readline support for pcretest.
497        - Added an listing of the option settings after cmake has run.
498    
499    4.  A user submitted a patch to Makefile that makes it easy to create
500        "pcre.dll" under mingw when using Configure/Make. I added stuff to
501        Makefile.am that cause it to include this special target, without
502        affecting anything else. Note that the same mingw target plus all
503        the other distribution libraries and programs are now supported
504        when configuring with CMake (see 6 below) instead of with
505        Configure/Make.
506    
507    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
508        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
509        exported in the Windows port". It has not yet been confirmed that the patch
510        solves the problem, but it does no harm.
511    
512    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
513        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
514        with CMake, and also correct the comment about stack recursion.
515    
516    7.  Remove the automatic building of pcredemo from the ./configure system and
517        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
518        of a program that users should build themselves after PCRE is installed, so
519        building it automatically is not really right. What is more, it gave
520        trouble in some build environments.
521    
522    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
523    
524    
525    Version 7.5 10-Jan-08
526    ---------------------
527    
528    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
529        values in parens when parsing an RE using the C++ wrapper."
530    
531    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
532        Characters greater than 255 were excluded from the class instead of being
533        included.
534    
535    3.  The same bug as (2) above applied to negated POSIX classes such as
536        [:^space:].
537    
538    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
539        defined or documented. It seems to have been a typo for PCRE_STATIC, so
540        I have changed it.
541    
542    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
543        first named subpattern) and a construct such as (?&a) would reference the
544        first named subpattern whose name started with "a" (in other words, the
545        length check was missing). Both these problems are fixed. "Subpattern name
546        expected" is now given for (?&) (a zero-length name), and this patch also
547        makes it give the same error for \k'' (previously it complained that that
548        was a reference to a non-existent subpattern).
549    
550    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
551        this is right because (?- can be followed by option settings as well as by
552        digits. I have, however, made the messages clearer.
553    
554    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
555        than the number used in the conditional) now cause a compile-time error.
556        This is actually not compatible with Perl, which accepts such patterns, but
557        treats the conditional as always being FALSE (as PCRE used to), but it
558        seems to me that giving a diagnostic is better.
559    
560    8.  Change "alphameric" to the more common word "alphanumeric" in comments
561        and messages.
562    
563    9.  Fix two occurrences of "backslash" in comments that should have been
564        "backspace".
565    
566    10. Remove two redundant lines of code that can never be obeyed (their function
567        was moved elsewhere).
568    
569    11. The program that makes PCRE's Unicode character property table had a bug
570        which caused it to generate incorrect table entries for sequences of
571        characters that have the same character type, but are in different scripts.
572        It amalgamated them into a single range, with the script of the first of
573        them. In other words, some characters were in the wrong script. There were
574        thirteen such cases, affecting characters in the following ranges:
575    
576          U+002b0 - U+002c1
577          U+0060c - U+0060d
578          U+0061e - U+00612
579          U+0064b - U+0065e
580          U+0074d - U+0076d
581          U+01800 - U+01805
582          U+01d00 - U+01d77
583          U+01d9b - U+01dbf
584          U+0200b - U+0200f
585          U+030fc - U+030fe
586          U+03260 - U+0327f
587          U+0fb46 - U+0fbb1
588          U+10450 - U+1049d
589    
590    12. The -o option (show only the matching part of a line) for pcregrep was not
591        compatible with GNU grep in that, if there was more than one match in a
592        line, it showed only the first of them. It now behaves in the same way as
593        GNU grep.
594    
595    13. If the -o and -v options were combined for pcregrep, it printed a blank
596        line for every non-matching line. GNU grep prints nothing, and pcregrep now
597        does the same. The return code can be used to tell if there were any
598        non-matching lines.
599    
600    14. Added --file-offsets and --line-offsets to pcregrep.
601    
602    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
603        infinitely looping recursion. The bug was that positive lookaheads were not
604        being skipped when checking for a possible empty match (negative lookaheads
605        and both kinds of lookbehind were skipped).
606    
607    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
608        inclusion of <windows.h> to before rather than after the definition of
609        INVALID_FILE_ATTRIBUTES (patch from David Byron).
610    
611    17. Specifying a possessive quantifier with a specific limit for a Unicode
612        character property caused pcre_compile() to compile bad code, which led at
613        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
614        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
615        caused the error; without that there was no problem.
616    
617    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
618    
619    19. Added --enable-pcretest-libreadline.
620    
621    20. In pcrecpp.cc, the variable 'count' was incremented twice in
622        RE::GlobalReplace(). As a result, the number of replacements returned was
623        double what it should be. I removed one of the increments, but Craig sent a
624        later patch that removed the other one (the right fix) and added unit tests
625        that check the return values (which was not done before).
626    
627    21. Several CMake things:
628    
629        (1) Arranged that, when cmake is used on Unix, the libraries end up with
630            the names libpcre and libpcreposix, not just pcre and pcreposix.
631    
632        (2) The above change means that pcretest and pcregrep are now correctly
633            linked with the newly-built libraries, not previously installed ones.
634    
635        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
636    
637    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
638        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
639        UTF-8 newline character). The key issue is that the pattern starts .*;
640        this means that the match must be either at the beginning, or after a
641        newline. The bug was in the code for advancing after a failed match and
642        checking that the new position followed a newline. It was not taking
643        account of UTF-8 characters correctly.
644    
645    23. PCRE was behaving differently from Perl in the way it recognized POSIX
646        character classes. PCRE was not treating the sequence [:...:] as a
647        character class unless the ... were all letters. Perl, however, seems to
648        allow any characters between [: and :], though of course it rejects as
649        unknown any "names" that contain non-letters, because all the known class
650        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
651        for example, whereas PCRE did not - it did not recognize a POSIX character
652        class. This seemed a bit dangerous, so the code has been changed to be
653        closer to Perl. The behaviour is not identical to Perl, because PCRE will
654        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
655        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
656        Perl does, and where it didn't before.
657    
658    24. Rewrite so as to remove the single use of %n from pcregrep because in some
659        Windows environments %n is disabled by default.
660    
661    
662    Version 7.4 21-Sep-07
663    ---------------------
664    
665    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
666        means that a class such as [\s] counted as "explicit reference to CR or
667        LF". That isn't really right - the whole point of the change was to try to
668        help when there was an actual mention of one of the two characters. So now
669        the change happens only if \r or \n (or a literal CR or LF) character is
670        encountered.
671    
672    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
673        of both had grown to the point where there were only 3 bits left.
674        Fortunately, there was spare space in the data structure, and so I have
675        moved the internal flags into a new 16-bit field to free up more option
676        bits.
677    
678    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
679        but did not set the internal JCHANGED flag - either of these is enough to
680        control the way the "get" function works - but the PCRE_INFO_JCHANGED
681        facility is supposed to tell if (?J) was ever used, so now (?J) at the
682        start sets both bits.
683    
684    4.  Added options (at build time, compile time, exec time) to change \R from
685        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
686    
687    5.  doc/pcresyntax.html was missing from the distribution.
688    
689    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
690        compatibility, even though it is no longer used.
691    
692    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
693        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
694        windows.h file is present (where different names are used). [This was
695        reversed later after testing - see 16 below.]
696    
697    8.  Changed all #include <config.h> to #include "config.h". There were also
698        some further <pcre.h> cases that I changed to "pcre.h".
699    
700    9.  When pcregrep was used with the --colour option, it missed the line ending
701        sequence off the lines that it output.
702    
703    10. It was pointed out to me that arrays of string pointers cause lots of
704        relocations when a shared library is dynamically loaded. A technique of
705        using a single long string with a table of offsets can drastically reduce
706        these. I have refactored PCRE in four places to do this. The result is
707        dramatic:
708    
709          Originally:                          290
710          After changing UCP table:            187
711          After changing error message table:   43
712          After changing table of "verbs"       36
713          After changing table of Posix names   22
714    
715        Thanks to the folks working on Gregex for glib for this insight.
716    
717    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
718        unicode-properties was also set.
719    
720    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
721    
722    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
723        checked only for CRLF.
724    
725    14. Added casts to pcretest.c to avoid compiler warnings.
726    
727    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
728    
729    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
730        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
731        entirely. This removes changes made in 7 above.
732    
733    17. The CMake files have been updated, and there is now more information about
734        building with CMake in the NON-UNIX-USE document.
735    
736    
737    Version 7.3 28-Aug-07
738    ---------------------
739    
740     1. In the rejigging of the build system that eventually resulted in 7.1, the
741        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
742        brackets there is not right, since it causes compilers to look for an
743        installed pcre.h, not the version that is in the source that is being
744        compiled (which of course may be different). I have changed it back to:
745    
746          #include "pcre.h"
747    
748        I have a vague recollection that the change was concerned with compiling in
749        different directories, but in the new build system, that is taken care of
750        by the VPATH setting the Makefile.
751    
752     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
753        when the subject happened to end in the byte 0x85 (e.g. if the last
754        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
755        characters but of course it shouldn't be taken as a newline when it is part
756        of another character. The bug was that, for an unlimited repeat of . in
757        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
758        characters when looking for a newline.
759    
760     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
761    
762     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
763        in debug output.
764    
765     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
766        long printing in the pcrecpp unittest when running under MinGW.
767    
768     6. ESC_K was left out of the EBCDIC table.
769    
770     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
771        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
772        limit also applies to "virtual nesting" when a pattern is recursive, and in
773        this case 1000 isn't so big. I have been able to remove this limit at the
774        expense of backing off one optimization in certain circumstances. Normally,
775        when pcre_exec() would call its internal match() function recursively and
776        immediately return the result unconditionally, it uses a "tail recursion"
777        feature to save stack. However, when a subpattern that can match an empty
778        string has an unlimited repetition quantifier, it no longer makes this
779        optimization. That gives it a stack frame in which to save the data for
780        checking that an empty string has been matched. Previously this was taken
781        from the 1000-entry workspace that had been reserved. So now there is no
782        explicit limit, but more stack is used.
783    
784     8. Applied Daniel's patches to solve problems with the import/export magic
785        syntax that is required for Windows, and which was going wrong for the
786        pcreposix and pcrecpp parts of the library. These were overlooked when this
787        problem was solved for the main library.
788    
789     9. There were some crude static tests to avoid integer overflow when computing
790        the size of patterns that contain repeated groups with explicit upper
791        limits. As the maximum quantifier is 65535, the maximum group length was
792        set at 30,000 so that the product of these two numbers did not overflow a
793        32-bit integer. However, it turns out that people want to use groups that
794        are longer than 30,000 bytes (though not repeat them that many times).
795        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
796        made it possible to implement the integer overflow checks in a much more
797        dynamic way, which I have now done. The artificial limitation on group
798        length has been removed - we now have only the limit on the total length of
799        the compiled pattern, which depends on the LINK_SIZE setting.
800    
801    10. Fixed a bug in the documentation for get/copy named substring when
802        duplicate names are permitted. If none of the named substrings are set, the
803        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
804        empty string.
805    
806    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
807        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
808        because the ] is interpreted as the first data character and the
809        terminating ] is not found. PCRE has been made compatible with Perl in this
810        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
811        cause memory overwriting.
812    
813    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
814        string has been matched (to stop an infinite loop). It was not recognizing
815        a conditional subpattern that could match an empty string if that
816        subpattern was within another subpattern. For example, it looped when
817        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
818        condition was not nested. This bug has been fixed.
819    
820    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
821        past the start of the subject in the presence of bytes with the top bit
822        set, for example "\x8aBCD".
823    
824    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
825        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
826    
827    14. Optimized (?!) to (*FAIL).
828    
829    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
830        This restricts code points to be within the range 0 to 0x10FFFF, excluding
831        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
832        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
833        does: it's just the validity check that is more restrictive.
834    
835    16. Inserted checks for integer overflows during escape sequence (backslash)
836        processing, and also fixed erroneous offset values for syntax errors during
837        backslash processing.
838    
839    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
840        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
841    
842    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
843        caused an overrun.
844    
845    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
846        something other than just ASCII characters) inside a group that had an
847        unlimited repeat caused a loop at compile time (while checking to see
848        whether the group could match an empty string).
849    
850    20. Debugging a pattern containing \p or \P could cause a crash. For example,
851        [\P{Any}] did so. (Error in the code for printing property names.)
852    
853    21. An orphan \E inside a character class could cause a crash.
854    
855    22. A repeated capturing bracket such as (A)? could cause a wild memory
856        reference during compilation.
857    
858    23. There are several functions in pcre_compile() that scan along a compiled
859        expression for various reasons (e.g. to see if it's fixed length for look
860        behind). There were bugs in these functions when a repeated \p or \P was
861        present in the pattern. These operators have additional parameters compared
862        with \d, etc, and these were not being taken into account when moving along
863        the compiled data. Specifically:
864    
865        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
866            length.
867    
868        (b) An item such as \pL+ within a repeated group could cause crashes or
869            loops.
870    
871        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
872            "reference to non-existent subpattern" error.
873    
874        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
875    
876    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
877        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
878    
879    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
880    
881    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
882        character were causing crashes (broken optimization).
883    
884    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
885        \p or \P) caused a compile-time loop.
886    
887    28. More problems have arisen in unanchored patterns when CRLF is a valid line
888        break. For example, the unstudied pattern [\r\n]A does not match the string
889        "\r\nA" because change 7.0/46 below moves the current point on by two
890        characters after failing to match at the start. However, the pattern \nA
891        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
892        the same is true. There doesn't seem any very clean way out of this, but
893        what I have chosen to do makes the common cases work: PCRE now takes note
894        of whether there can be an explicit match for \r or \n anywhere in the
895        pattern, and if so, 7.0/46 no longer applies. As part of this change,
896        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
897        pattern has explicit CR or LF references.
898    
899    29. Added (*CR) etc for changing newline setting at start of pattern.
900    
901    
902    Version 7.2 19-Jun-07
903    ---------------------
904    
905     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
906        which is apparently normally available under Windows.
907    
908     2. Re-jig the pcregrep tests with different newline settings in an attempt
909        to make them independent of the local environment's newline setting.
910    
911     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
912    
913     4. Some of the "internals" tests were previously cut out when the link size
914        was not 2, because the output contained actual offsets. The recent new
915        "Z" feature of pcretest means that these can be cut out, making the tests
916        usable with all link sizes.
917    
918     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
919        stack recursion. This gives a massive performance boost under BSD, but just
920        a small improvement under Linux. However, it saves one field in the frame
921        in all cases.
922    
923     6. Added more features from the forthcoming Perl 5.10:
924    
925        (a) (?-n) (where n is a string of digits) is a relative subroutine or
926            recursion call. It refers to the nth most recently opened parentheses.
927    
928        (b) (?+n) is also a relative subroutine call; it refers to the nth next
929            to be opened parentheses.
930    
931        (c) Conditions that refer to capturing parentheses can be specified
932            relatively, for example, (?(-2)... or (?(+3)...
933    
934        (d) \K resets the start of the current match so that everything before
935            is not part of it.
936    
937        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
938    
939        (f) \g{name} is another synonym - part of Perl 5.10's unification of
940            reference syntax.
941    
942        (g) (?| introduces a group in which the numbering of parentheses in each
943            alternative starts with the same number.
944    
945        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
946    
947     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
948        PCRE_INFO_JCHANGED.
949    
950     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
951        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
952        for detecting groups that can match an empty string.
953    
954     9. A pattern with a very large number of alternatives (more than several
955        hundred) was running out of internal workspace during the pre-compile
956        phase, where pcre_compile() figures out how much memory will be needed. A
957        bit of new cunning has reduced the workspace needed for groups with
958        alternatives. The 1000-alternative test pattern now uses 12 bytes of
959        workspace instead of running out of the 4096 that are available.
960    
961    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
962    
963    11. Applied patch from Google to remove an optimization that didn't quite work.
964        The report of the bug said:
965    
966          pcrecpp::RE("a*").FullMatch("aaa") matches, while
967          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
968          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
969    
970    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
971        it matched the wrong number of bytes.
972    
973    
974    Version 7.1 24-Apr-07
975    ---------------------
976    
977     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
978        that is more "standard", making use of automake and other Autotools. There
979        is some re-arrangement of the files and adjustment of comments consequent
980        on this.
981    
982     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
983        for recursive directory scanning broke on some systems because the files
984        are not scanned in any specific order and on different systems the order
985        was different. A call to "sort" has been inserted into RunGrepTest for the
986        approprate test as a short-term fix. In the longer term there may be an
987        alternative.
988    
989     3. I had an email from Eric Raymond about problems translating some of PCRE's
990        man pages to HTML (despite the fact that I distribute HTML pages, some
991        people do their own conversions for various reasons). The problems
992        concerned the use of low-level troff macros .br and .in. I have therefore
993        removed all such uses from the man pages (some were redundant, some could
994        be replaced by .nf/.fi pairs). The 132html script that I use to generate
995        HTML has been updated to handle .nf/.fi and to complain if it encounters
996        .br or .in.
997    
998     4. Updated comments in configure.ac that get placed in config.h.in and also
999        arranged for config.h to be included in the distribution, with the name
1000        config.h.generic, for the benefit of those who have to compile without
1001        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1002    
1003     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1004        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1005        makevp.bat for the current PCRE, using the additional files
1006        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1007    
1008     6. A Windows user reported a minor discrepancy with test 2, which turned out
1009        to be caused by a trailing space on an input line that had got lost in his
1010        copy. The trailing space was an accident, so I've just removed it.
1011    
1012     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1013        that is needed.
1014    
1015     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1016        as "const" (a) because they are and (b) because it helps the PHP
1017        maintainers who have recently made a script to detect big data structures
1018        in the php code that should be moved to the .rodata section. I remembered
1019        to update Builducptable as well, so it won't revert if ucptable.h is ever
1020        re-created.
1021    
1022     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1023        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1024        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1025        support is not required. This saves 1.5-2K of code, which is important in
1026        some applications.
1027    
1028        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1029        so as not to refer to the tables, even though these functions will never be
1030        called when UTF-8 support is disabled. Otherwise there are problems with a
1031        shared library.
1032    
1033    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1034    
1035        (a) It was defining its arguments as char * instead of void *.
1036    
1037        (b) It was assuming that all moves were upwards in memory; this was true
1038            a long time ago when I wrote it, but is no longer the case.
1039    
1040        The emulated memove() is provided for those environments that have neither
1041        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1042        is clearly not the case, as these two bugs were recently reported.
1043    
1044    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1045        and Detrail to create the HTML documentation, the .txt form of the man
1046        pages, and it removes trailing spaces from listed files. It also creates
1047        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1048        case, it wraps all the #defines with #ifndefs. This script should be run
1049        before "make dist".
1050    
1051    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1052        with Unicode property support.
1053    
1054        (a) For a maximizing quantifier, if the two different cases of the
1055            character were of different lengths in their UTF-8 codings (there are
1056            some cases like this - I found 11), and the matching function had to
1057            back up over a mixture of the two cases, it incorrectly assumed they
1058            were both the same length.
1059    
1060        (b) When PCRE was configured to use the heap rather than the stack for
1061            recursion during matching, it was not correctly preserving the data for
1062            the other case of a UTF-8 character when checking ahead for a match
1063            while processing a minimizing repeat. If the check also involved
1064            matching a wide character, but failed, corruption could cause an
1065            erroneous result when trying to check for a repeat of the original
1066            character.
1067    
1068    13. Some tidying changes to the testing mechanism:
1069    
1070        (a) The RunTest script now detects the internal link size and whether there
1071            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1072            values substituted by "configure". (The RunGrepTest script already did
1073            this for UTF-8.) The configure.ac script no longer substitutes the
1074            relevant variables.
1075    
1076        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1077            with length and offset values. This means that the output is different
1078            for different internal link sizes. Test 2 is skipped for link sizes
1079            other than 2 because of this, bypassing the problem. Unfortunately,
1080            there was also a test in test 3 (the locale tests) that used /B and
1081            failed for link sizes other than 2. Rather than cut the whole test out,
1082            I have added a new /Z option to pcretest that replaces the length and
1083            offset values with spaces. This is now used to make test 3 independent
1084            of link size. (Test 2 will be tidied up later.)
1085    
1086    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1087        segmentation fault instead of returning the appropriate error message.
1088    
1089    15. In multiline mode when the newline sequence was set to "any", the pattern
1090        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1091        This doesn't seem right; it now treats the CRLF combination as the line
1092        ending, and so does not match in that case. It's only a pattern such as ^$
1093        that would hit this one: something like ^ABC$ would have failed after \r
1094        and then tried again after \r\n.
1095    
1096    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1097        in an attempt to make files that differ only in their line terminators
1098        compare equal. This works on Linux.
1099    
1100    17. Under certain error circumstances pcregrep might try to free random memory
1101        as it exited. This is now fixed, thanks to valgrind.
1102    
1103    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1104        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1105        was because its rules for how to advance for /g after matching an empty
1106        string at the end of a line did not allow for this case. They now check for
1107        it specially.
1108    
1109    20. pcretest is supposed to handle patterns and data of any length, by
1110        extending its buffers when necessary. It was getting this wrong when the
1111        buffer for a data line had to be extended.
1112    
1113    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1114        CRLF as a newline sequence.
1115    
1116    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1117        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1118        I have nevertheless tidied it up.
1119    
1120    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1121    
1122    24. Added a man page for pcre-config.
1123    
1124    
1125    Version 7.0 19-Dec-06
1126    ---------------------
1127    
1128     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1129        moving to gcc 4.1.1.
1130    
1131     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1132        sys/time.h, which is documented as needed for this function. It doesn't
1133        seem to matter on Linux, but it showed up on some releases of OS X.
1134    
1135     3. It seems that there are systems where bytes whose values are greater than
1136        127 match isprint() in the "C" locale. The "C" locale should be the
1137        default when a C program starts up. In most systems, only ASCII printing
1138        characters match isprint(). This difference caused the output from pcretest
1139        to vary, making some of the tests fail. I have changed pcretest so that:
1140    
1141        (a) When it is outputting text in the compiled version of a pattern, bytes
1142            other than 32-126 are always shown as hex escapes.
1143    
1144        (b) When it is outputting text that is a matched part of a subject string,
1145            it does the same, unless a different locale has been set for the match
1146            (using the /L modifier). In this case, it uses isprint() to decide.
1147    
1148     4. Fixed a major bug that caused incorrect computation of the amount of memory
1149        required for a compiled pattern when options that changed within the
1150        pattern affected the logic of the preliminary scan that determines the
1151        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1152        that the computed length was too small. The symptoms of this bug were
1153        either the PCRE error "internal error: code overflow" from pcre_compile(),
1154        or a glibc crash with a message such as "pcretest: free(): invalid next
1155        size (fast)". Examples of patterns that provoked this bug (shown in
1156        pcretest format) are:
1157    
1158          /(?-x: )/x
1159          /(?x)(?-x: \s*#\s*)/
1160          /((?i)[\x{c0}])/8
1161          /(?i:[\x{c0}])/8
1162    
1163        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1164        is now done differently.
1165    
1166     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1167        wrapper classes; (b) implement a new function in the C++ scanner that is
1168        more efficient than the old way of doing things because it avoids levels of
1169        recursion in the regex matching; (c) add a paragraph to the documentation
1170        for the FullMatch() function.
1171    
1172     6. The escape sequence \n was being treated as whatever was defined as
1173        "newline". Not only was this contrary to the documentation, which states
1174        that \n is character 10 (hex 0A), but it also went horribly wrong when
1175        "newline" was defined as CRLF. This has been fixed.
1176    
1177     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1178        was being set to -1 for the "end of line" case (supposedly a value that no
1179        character can have). Though this value is never used (the check for end of
1180        line is "zero bytes in current character"), it caused compiler complaints.
1181        I've changed it to 0xffffffff.
1182    
1183     8. In pcre_version.c, the version string was being built by a sequence of
1184        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1185        string (as it is for production releases) called a macro with an empty
1186        argument. The C standard says the result of this is undefined. The gcc
1187        compiler treats it as an empty string (which was what was wanted) but it is
1188        reported that Visual C gives an error. The source has been hacked around to
1189        avoid this problem.
1190    
1191     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1192        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1193        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1194        of them did).
1195    
1196    10. Originally, pcretest opened its input and output without "b"; then I was
1197        told that "b" was needed in some environments, so it was added for release
1198        5.0 to both the input and output. (It makes no difference on Unix-like
1199        systems.) Later I was told that it is wrong for the input on Windows. I've
1200        now abstracted the modes into two macros, to make it easier to fiddle with
1201        them, and removed "b" from the input mode under Windows.
1202    
1203    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1204    
1205    12. Added -help and --help to pcretest as an official way of being reminded
1206        of the options.
1207    
1208    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1209        and pcrecpp.cc because they annoy compilers at high warning levels.
1210    
1211    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1212    
1213    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1214        scripts are not C programs :-) and which was not noticed because it works
1215        on Linux.
1216    
1217    16. pcretest is supposed to handle any length of pattern and data line (as one
1218        line or as a continued sequence of lines) by extending its input buffer if
1219        necessary. This feature was broken for very long pattern lines, leading to
1220        a string of junk being passed to pcre_compile() if the pattern was longer
1221        than about 50K.
1222    
1223    17. I have done a major re-factoring of the way pcre_compile() computes the
1224        amount of memory needed for a compiled pattern. Previously, there was code
1225        that made a preliminary scan of the pattern in order to do this. That was
1226        OK when PCRE was new, but as the facilities have expanded, it has become
1227        harder and harder to keep it in step with the real compile phase, and there
1228        have been a number of bugs (see for example, 4 above). I have now found a
1229        cunning way of running the real compile function in a "fake" mode that
1230        enables it to compute how much memory it would need, while actually only
1231        ever using a few hundred bytes of working memory and without too many
1232        tests of the mode. This should make future maintenance and development
1233        easier. A side effect of this work is that the limit of 200 on the nesting
1234        depth of parentheses has been removed (though this was never a serious
1235        limitation, I suspect). However, there is a downside: pcre_compile() now
1236        runs more slowly than before (30% or more, depending on the pattern). I
1237        hope this isn't a big issue. There is no effect on runtime performance.
1238    
1239    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1240        newline (only possible for the last line of a file) and it was a
1241        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1242    
1243    19. Added additional timing features to pcretest. (1) The -tm option now times
1244        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1245        separate command line item, by a number that specifies the number of
1246        repeats to use when timing. The default is 50000; this gives better
1247        precision, but takes uncomfortably long for very large patterns.
1248    
1249    20. Extended pcre_study() to be more clever in cases where a branch of a
1250        subpattern has no definite first character. For example, (a*|b*)[cd] would
1251        previously give no result from pcre_study(). Now it recognizes that the
1252        first character must be a, b, c, or d.
1253    
1254    21. There was an incorrect error "recursive call could loop indefinitely" if
1255        a subpattern (or the entire pattern) that was being tested for matching an
1256        empty string contained only one non-empty item after a nested subpattern.
1257        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1258        incorrectly, because the \d was being skipped in the check.
1259    
1260    22. The pcretest program now has a new pattern option /B and a command line
1261        option -b, which is equivalent to adding /B to every pattern. This causes
1262        it to show the compiled bytecode, without the additional information that
1263        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1264        is the same as /B/I).
1265    
1266    23. A new optimization is now able automatically to treat some sequences such
1267        as a*b as a*+b. More specifically, if something simple (such as a character
1268        or a simple class like \d) has an unlimited quantifier, and is followed by
1269        something that cannot possibly match the quantified thing, the quantifier
1270        is automatically "possessified".
1271    
1272    24. A recursive reference to a subpattern whose number was greater than 39
1273        went wrong under certain circumstances in UTF-8 mode. This bug could also
1274        have affected the operation of pcre_study().
1275    
1276    25. Realized that a little bit of performance could be had by replacing
1277        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1278    
1279    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1280    
1281    27. Possessive quantifiers such as a++ were previously implemented by turning
1282        them into atomic groups such as ($>a+). Now they have their own opcodes,
1283        which improves performance. This includes the automatically created ones
1284        from 23 above.
1285    
1286    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1287        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1288        the first matched character to be a colon. This applied both to named and
1289        numbered groups.
1290    
1291    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1292    
1293    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1294        building PCRE on Windows easier, so I have included it in the distribution.
1295    
1296    31. There is now a check in pcretest against a ridiculously large number being
1297        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1298        loop, the loop is abandoned.
1299    
1300    32. Forward references to subpatterns in conditions such as (?(2)...) where
1301        subpattern 2 is defined later cause pcre_compile() to search forwards in
1302        the pattern for the relevant set of parentheses. This search went wrong
1303        when there were unescaped parentheses in a character class, parentheses
1304        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1305    
1306    33. "Subroutine" calls and backreferences were previously restricted to
1307        referencing subpatterns earlier in the regex. This restriction has now
1308        been removed.
1309    
1310    34. Added a number of extra features that are going to be in Perl 5.10. On the
1311        whole, these are just syntactic alternatives for features that PCRE had
1312        previously implemented using the Python syntax or my own invention. The
1313        other formats are all retained for compatibility.
1314    
1315        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1316            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1317            also .NET compatible.
1318    
1319        (b) A recursion or subroutine call to a named group can now be defined as
1320            (?&name) as well as (?P>name).
1321    
1322        (c) A backreference to a named group can now be defined as \k<name> or
1323            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1324            5.10, are also .NET compatible.
1325    
1326        (d) A conditional reference to a named group can now use the syntax
1327            (?(<name>) or (?('name') as well as (?(name).
1328    
1329        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1330            groups (named and numbered) that are never evaluated inline, but can be
1331            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1332            is always false. There may be only one alternative in such a group.
1333    
1334        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1335            as the simple (?(R). The condition is true only if the most recent
1336            recursion is that of the given number or name. It does not search out
1337            through the entire recursion stack.
1338    
1339        (g) The escape \gN or \g{N} has been added, where N is a positive or
1340            negative number, specifying an absolute or relative reference.
1341    
1342    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1343        some "unreachable code" warnings.
1344    
1345    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1346        things, this adds five new scripts.
1347    
1348    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1349        There were also incompatibilities regarding the handling of \Q..\E inside
1350        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1351        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1352    
1353    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1354        matches an empty string, and forcibly breaks the loop. There were bugs in
1355        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1356        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1357        separate and independent bugs (that affected different cases) have been
1358        fixed.
1359    
1360    39. Refactored the code to abolish the use of different opcodes for small
1361        capturing bracket numbers. This is a tidy that I avoided doing when I
1362        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1363        The new approach is not only tidier, it makes it possible to reduce the
1364        memory needed to fix the previous bug (38).
1365    
1366    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1367        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1368        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1369        mode.
1370    
1371    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1372        report.
1373    
1374    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1375        copy construction and assignment in the C++ wrapper.
1376    
1377    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1378        couple of bugs that could have given wrong results in the "--newline=crlf"
1379        case.
1380    
1381    44. Added a number of casts and did some reorganization of signed/unsigned int
1382        variables following suggestions from Dair Grant. Also renamed the variable
1383        "this" as "item" because it is a C++ keyword.
1384    
1385    45. Arranged for dftables to add
1386    
1387          #include "pcre_internal.h"
1388    
1389        to pcre_chartables.c because without it, gcc 4.x may remove the array
1390        definition from the final binary if PCRE is built into a static library and
1391        dead code stripping is activated.
1392    
1393    46. For an unanchored pattern, if a match attempt fails at the start of a
1394        newline sequence, and the newline setting is CRLF or ANY, and the next two
1395        characters are CRLF, advance by two characters instead of one.
1396    
1397    
1398    Version 6.7 04-Jul-06
1399    ---------------------
1400    
1401     1. In order to handle tests when input lines are enormously long, pcretest has
1402        been re-factored so that it automatically extends its buffers when
1403        necessary. The code is crude, but this _is_ just a test program. The
1404        default size has been increased from 32K to 50K.
1405    
1406     2. The code in pcre_study() was using the value of the re argument before
1407        testing it for NULL. (Of course, in any sensible call of the function, it
1408        won't be NULL.)
1409    
1410     3. The memmove() emulation function in pcre_internal.h, which is used on
1411        systems that lack both memmove() and bcopy() - that is, hardly ever -
1412        was missing a "static" storage class specifier.
1413    
1414     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1415        containing an extended class (one that cannot be represented by a bitmap
1416        because it contains high-valued characters or Unicode property items, e.g.
1417        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1418        pattern, but PCRE should not loop if you do not (it no longer does).
1419        [Detail: two cases were found: (a) a repeated subpattern containing an
1420        extended class; (b) a recursive reference to a subpattern that followed a
1421        previous extended class. It wasn't skipping over the extended class
1422        correctly when UTF-8 mode was not set.]
1423    
1424     5. A negated single-character class was not being recognized as fixed-length
1425        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1426        compile error "lookbehind assertion is not fixed length".
1427    
1428     6. The RunPerlTest auxiliary script was showing an unexpected difference
1429        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1430        write a Perl script that can interpret lines of an input file either as
1431        byte characters or as UTF-8, which is what "perltest" was being required to
1432        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1433        can't do is switch easily at run time between having the "use utf8;" pragma
1434        or not. In the end, I fudged it by using the RunPerlTest script to insert
1435        "use utf8;" explicitly for the UTF-8 tests.
1436    
1437     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1438        the end of the subject string, contrary to the documentation and to what
1439        Perl does. This was true of both matching functions. Now it matches only at
1440        the start of the subject and immediately after *internal* newlines.
1441    
1442     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1443        a pointer to an int instead of a pointer to an unsigned long int. This
1444        caused problems on 64-bit systems.
1445    
1446     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1447        instance of the 'standard' template library not being so standard".
1448    
1449    10. There was no check on the number of named subpatterns nor the maximum
1450        length of a subpattern name. The product of these values is used to compute
1451        the size of the memory block for a compiled pattern. By supplying a very
1452        long subpattern name and a large number of named subpatterns, the size
1453        computation could be caused to overflow. This is now prevented by limiting
1454        the length of names to 32 characters, and the number of named subpatterns
1455        to 10,000.
1456    
1457    11. Subpatterns that are repeated with specific counts have to be replicated in
1458        the compiled pattern. The size of memory for this was computed from the
1459        length of the subpattern and the repeat count. The latter is limited to
1460        65535, but there was no limit on the former, meaning that integer overflow
1461        could in principle occur. The compiled length of a repeated subpattern is
1462        now limited to 30,000 bytes in order to prevent this.
1463    
1464    12. Added the optional facility to have named substrings with the same name.
1465    
1466    13. Added the ability to use a named substring as a condition, using the
1467        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1468        are numbers (not recommended). Forward references are permitted.
1469    
1470    14. Added forward references in named backreferences (if you see what I mean).
1471    
1472    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1473        pattern could run off the end of the subject. For example, the pattern
1474        "(?s)(.{1,5})"8 did this with the subject "ab".
1475    
1476    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1477        PCRE_CASELESS was set when matching characters that were quantified with ?
1478        or *.
1479    
1480    17. A character class other than a single negated character that had a minimum
1481        but no maximum quantifier - for example [ab]{6,} - was not handled
1482        correctly by pce_dfa_exec(). It would match only one character.
1483    
1484    18. A valid (though odd) pattern that looked like a POSIX character
1485        class but used an invalid character after [ (for example [[,abc,]]) caused
1486        pcre_compile() to give the error "Failed: internal error: code overflow" or
1487        in some cases to crash with a glibc free() error. This could even happen if
1488        the pattern terminated after [[ but there just happened to be a sequence of
1489        letters, a binary zero, and a closing ] in the memory that followed.
1490    
1491    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1492        over the years. Originally (before any Unicode support), just the bottom 8
1493        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1494        output from "man perlunicode" includes this:
1495    
1496          The regular expression compiler produces polymorphic opcodes.  That
1497          is, the pattern adapts to the data and automatically switches to
1498          the Unicode character scheme when presented with Unicode data--or
1499          instead uses a traditional byte scheme when presented with byte
1500          data.
1501    
1502        Sadly, a wide octal escape does not cause a switch, and in a string with
1503        no other multibyte characters, these octal escapes are treated as before.
1504        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1505        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1506        Unicode string.
1507    
1508        I have not perpetrated such confusion in PCRE. Up till now, it took just
1509        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1510        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1511        translate to the appropriate multibyte character.
1512    
1513    29. Applied some refactoring to reduce the number of warnings from Microsoft
1514        and Borland compilers. This has included removing the fudge introduced
1515        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1516        a warning about an unused variable.
1517    
1518    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1519        characters since release 4.0, because Perl (from release 5.004) does not.
1520        [Or at least, is documented not to: some releases seem to be in conflict
1521        with the documentation.] However, when a pattern was studied with
1522        pcre_study() and all its branches started with \s, PCRE still included VT
1523        as a possible starting character. Of course, this did no harm; it just
1524        caused an unnecessary match attempt.
1525    
1526    22. Removed a now-redundant internal flag bit that recorded the fact that case
1527        dependency changed within the pattern. This was once needed for "required
1528        byte" processing, but is no longer used. This recovers a now-scarce options
1529        bit. Also moved the least significant internal flag bit to the most-
1530        significant bit of the word, which was not previously used (hangover from
1531        the days when it was an int rather than a uint) to free up another bit for
1532        the future.
1533    
1534    23. Added support for CRLF line endings as well as CR and LF. As well as the
1535        default being selectable at build time, it can now be changed at runtime
1536        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1537        specify that it is scanning data with non-default line endings.
1538    
1539    24. Changed the definition of CXXLINK to make it agree with the definition of
1540        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1541    
1542    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1543        recursions. This makes a big different to stack usage for some patterns.
1544    
1545    26. If a subpattern containing a named recursion or subroutine reference such
1546        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1547        the space required for the compiled pattern went wrong and gave too small a
1548        value. Depending on the environment, this could lead to "Failed: internal
1549        error: code overflow at offset 49" or "glibc detected double free or
1550        corruption" errors.
1551    
1552    27. Applied patches from Google (a) to support the new newline modes and (b) to
1553        advance over multibyte UTF-8 characters in GlobalReplace.
1554    
1555    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1556        difference for some implementation of PCRE in some Windows version.
1557    
1558    29. Added some extra testing facilities to pcretest:
1559    
1560        \q<number>   in a data line sets the "match limit" value
1561        \Q<number>   in a data line sets the "match recursion limt" value
1562        -S <number>  sets the stack size, where <number> is in megabytes
1563    
1564        The -S option isn't available for Windows.
1565    
1566    
1567    Version 6.6 06-Feb-06
1568    ---------------------
1569    
1570     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1571        in pcreposix.h. I have copied the definition from pcre.h.
1572    
1573     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1574        because pcre.h is no longer a built file.
1575    
1576     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1577        not normally included in the compiled code.
1578    
1579    
1580    Version 6.5 01-Feb-06
1581    ---------------------
1582    
1583     1. When using the partial match feature with pcre_dfa_exec(), it was not
1584        anchoring the second and subsequent partial matches at the new starting
1585        point. This could lead to incorrect results. For example, with the pattern
1586        /1234/, partially matching against "123" and then "a4" gave a match.
1587    
1588     2. Changes to pcregrep:
1589    
1590        (a) All non-match returns from pcre_exec() were being treated as failures
1591            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1592            error message is output. Some extra information is given for the
1593            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1594            probably the only errors that are likely to be caused by users (by
1595            specifying a regex that has nested indefinite repeats, for instance).
1596            If there are more than 20 of these errors, pcregrep is abandoned.
1597    
1598        (b) A binary zero was treated as data while matching, but terminated the
1599            output line if it was written out. This has been fixed: binary zeroes
1600            are now no different to any other data bytes.
1601    
1602        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1603            used to set a locale for matching. The --locale=xxxx long option has
1604            been added (no short equivalent) to specify a locale explicitly on the
1605            pcregrep command, overriding the environment variables.
1606    
1607        (d) When -B was used with -n, some line numbers in the output were one less
1608            than they should have been.
1609    
1610        (e) Added the -o (--only-matching) option.
1611    
1612        (f) If -A or -C was used with -c (count only), some lines of context were
1613            accidentally printed for the final match.
1614    
1615        (g) Added the -H (--with-filename) option.
1616    
1617        (h) The combination of options -rh failed to suppress file names for files
1618            that were found from directory arguments.
1619    
1620        (i) Added the -D (--devices) and -d (--directories) options.
1621    
1622        (j) Added the -F (--fixed-strings) option.
1623    
1624        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1625    
1626        (l) Added the --colo(u)r option.
1627    
1628        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1629            is not present by default.
1630    
1631     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1632        items such as (?R) or (?1), when the recursion could match a number of
1633        alternatives. If it matched one of the alternatives, but subsequently,
1634        outside the recursion, there was a failure, the code tried to back up into
1635        the recursion. However, because of the way PCRE is implemented, this is not
1636        possible, and the result was an incorrect result from the match.
1637    
1638        In order to prevent this happening, the specification of recursion has
1639        been changed so that all such subpatterns are automatically treated as
1640        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1641    
1642     4. I had overlooked the fact that, in some locales, there are characters for
1643        which isalpha() is true but neither isupper() nor islower() are true. In
1644        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1645        and ordfeminine) are like this. This affected the treatment of \w and \W
1646        when they appeared in character classes, but not when they appeared outside
1647        a character class. The bit map for "word" characters is now created
1648        separately from the results of isalnum() instead of just taking it from the
1649        upper, lower, and digit maps. (Plus the underscore character, of course.)
1650    
1651     5. The above bug also affected the handling of POSIX character classes such as
1652        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1653        permanent tables. Instead, the bit maps for such a class were previously
1654        created as the appropriate unions of the upper, lower, and digit bitmaps.
1655        Now they are created by subtraction from the [[:word:]] class, which has
1656        its own bitmap.
1657    
1658     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1659        It is created by subtracting the vertical space characters (\x09, \x0a,
1660        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1661        subtraction was done in the overall bitmap for a character class, meaning
1662        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1663        be recognized. This bug has been fixed.
1664    
1665     7. Patches from the folks at Google:
1666    
1667          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1668          real life, but is still worth protecting against".
1669    
1670          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1671          regular expressions".
1672    
1673          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1674          have it.
1675    
1676          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1677          "configure" and the latter not, in order to fix a problem somebody had
1678          with compiling the Arg class on HP-UX.
1679    
1680          (e) Improve the error-handling of the C++ wrapper a little bit.
1681    
1682          (f) New tests for checking recursion limiting.
1683    
1684     8. The pcre_memmove() function, which is used only if the environment does not
1685        have a standard memmove() function (and is therefore rarely compiled),
1686        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1687        returning a result (though PCRE never actually uses the result).
1688    
1689     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1690        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1691        returned instead of calling malloc() with an overflowing number that would
1692        most likely cause subsequent chaos.
1693    
1694    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1695    
1696    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1697        with this option is matched, the nmatch and pmatch options of regexec() are
1698        ignored.
1699    
1700    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1701        provided in case anyone wants to the the POSIX interface with UTF-8
1702        strings.
1703    
1704    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1705        C++ linking (needed for some HP-UX environments).
1706    
1707    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1708        (unused parameter) and in the pcre_printint() function (omitted "default"
1709        switch label when the default is to do nothing).
1710    
1711    15. Added some code to make it possible, when PCRE is compiled as a C++
1712        library, to replace subject pointers for pcre_exec() with a smart pointer
1713        class, thus making it possible to process discontinuous strings.
1714    
1715    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1716        much the same function. They were added by different people who were trying
1717        to make PCRE easy to compile on non-Unix systems. It has been suggested
1718        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1719        for compiling on Windows systems. I have therefore replaced it with
1720        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1721        defaults to "extern" for C or "extern C" for C++, which works fine on
1722        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1723        SCOPE with something explicit in config.h. In addition:
1724    
1725        (a) pcreposix.h still had just "extern" instead of either of these macros;
1726            I have replaced it with PCRE_DATA_SCOPE.
1727    
1728        (b) Functions such as _pcre_xclass(), which are internal to the library,
1729            but external in the C sense, all had PCRE_EXPORT in their definitions.
1730            This is apparently wrong for the Windows case, so I have removed it.
1731            (It makes no difference on Unix-like systems.)
1732    
1733    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1734        of recursive calls to match(). This is different to MATCH_LIMIT because
1735        that limits the total number of calls to match(), not all of which increase
1736        the depth of recursion. Limiting the recursion depth limits the amount of
1737        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1738        when PCRE is compiled, and changed at run time. A patch from Google adds
1739        this functionality to the C++ interface.
1740    
1741    18. Changes to the handling of Unicode character properties:
1742    
1743        (a) Updated the table to Unicode 4.1.0.
1744    
1745        (b) Recognize characters that are not in the table as "Cn" (undefined).
1746    
1747        (c) I revised the way the table is implemented to a much improved format
1748            which includes recognition of ranges. It now supports the ranges that
1749            are defined in UnicodeData.txt, and it also amalgamates other
1750            characters into ranges. This has reduced the number of entries in the
1751            table from around 16,000 to around 3,000, thus reducing its size
1752            considerably. I realized I did not need to use a tree structure after
1753            all - a binary chop search is just as efficient. Having reduced the
1754            number of entries, I extended their size from 6 bytes to 8 bytes to
1755            allow for more data.
1756    
1757        (d) Added support for Unicode script names via properties such as \p{Han}.
1758    
1759    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1760        matching that character.
1761    
1762    20. When matching a repeated Unicode property with a minimum greater than zero,
1763        (for example \pL{2,}), PCRE could look past the end of the subject if it
1764        reached it while seeking the minimum number of characters. This could
1765        happen only if some of the characters were more than one byte long, because
1766        there is a check for at least the minimum number of bytes.
1767    
1768    21. Refactored the implementation of \p and \P so as to be more general, to
1769        allow for more different types of property in future. This has changed the
1770        compiled form incompatibly. Anybody with saved compiled patterns that use
1771        \p or \P will have to recompile them.
1772    
1773    22. Added "Any" and "L&" to the supported property types.
1774    
1775    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1776        but give a compile time error if the value is greater than 0xff.
1777    
1778    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1779        accidentally not being installed or uninstalled.
1780    
1781    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1782        made were to insert the current release number. This seemed silly, because
1783        it made things harder for people building PCRE on systems that don't run
1784        "configure". I have turned pcre.h into a distributed file, no longer built
1785        by "configure", with the version identification directly included. There is
1786        no longer a pcre.h.in file.
1787    
1788        However, this change necessitated a change to the pcre-config script as
1789        well. It is built from pcre-config.in, and one of the substitutions was the
1790        release number. I have updated configure.ac so that ./configure now finds
1791        the release number by grepping pcre.h.
1792    
1793    26. Added the ability to run the tests under valgrind.
1794    
1795    
1796    Version 6.4 05-Sep-05
1797    ---------------------
1798    
1799     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1800        "--" to be printed when multiple files were scanned, even when none of the
1801        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1802        consider it to be a bug, and have restored the previous behaviour.
1803    
1804     2. A couple of code tidies to get rid of compiler warnings.
1805    
1806     3. The pcretest program used to cheat by referring to symbols in the library
1807        whose names begin with _pcre_. These are internal symbols that are not
1808        really supposed to be visible externally, and in some environments it is
1809        possible to suppress them. The cheating is now confined to including
1810        certain files from the library's source, which is a bit cleaner.
1811    
1812     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1813        file's purpose clearer.
1814    
1815     5. Reorganized pcre_ucp_findchar().
1816    
1817    
1818    Version 6.3 15-Aug-05
1819    ---------------------
1820    
1821     1. The file libpcre.pc.in did not have general read permission in the tarball.
1822    
1823     2. There were some problems when building without C++ support:
1824    
1825        (a) If C++ support was not built, "make install" and "make test" still
1826            tried to test it.
1827    
1828        (b) There were problems when the value of CXX was explicitly set. Some
1829            changes have been made to try to fix these, and ...
1830    
1831        (c) --disable-cpp can now be used to explicitly disable C++ support.
1832    
1833        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1834            backslash in a target when C++ was disabled. This confuses some
1835            versions of "make", apparently. Using an intermediate variable solves
1836            this. (Same for CPP_LOBJ.)
1837    
1838     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1839        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1840        necessary on certain architectures.
1841    
1842     4. Added a setting of -export-symbols-regex to the link command to remove
1843        those symbols that are exported in the C sense, but actually are local
1844        within the library, and not documented. Their names all begin with
1845        "_pcre_". This is not a perfect job, because (a) we have to except some
1846        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1847        available (and never for static libraries). I have made a note to try to
1848        find a way round (a) in the future.
1849    
1850    
1851    Version 6.2 01-Aug-05
1852    ---------------------
1853    
1854     1. There was no test for integer overflow of quantifier values. A construction
1855        such as {1111111111111111} would give undefined results. What is worse, if
1856        a minimum quantifier for a parenthesized subpattern overflowed and became
1857        negative, the calculation of the memory size went wrong. This could have
1858        led to memory overwriting.
1859    
1860     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1861    
1862     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1863        operating environments where this matters.
1864    
1865     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1866        PCRE options from within the C++ wrapper.
1867    
1868     5. Named capturing subpatterns were not being correctly counted when a pattern
1869        was compiled. This caused two problems: (a) If there were more than 100
1870        such subpatterns, the calculation of the memory needed for the whole
1871        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1872        back references of the form \12, where the number was greater than 9, were
1873        not recognized as back references, even though there were sufficient
1874        previous subpatterns.
1875    
1876     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1877        versions of gcc, e.g. 2.95.4.
1878    
1879    
1880  Version 6.1 21-Jun-05  Version 6.1 21-Jun-05
1881  ---------------------  ---------------------
1882    

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