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8        was out-of-date, and there was no check on the pcre_compile() error code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

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