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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 12-Mar-07  Version 8.01 11-Dec-09
5    ----------------------
6    
7    1.  If a pattern contained a conditional subpattern with only one branch (in
8        particular, this includes all (DEFINE) patterns), a call to pcre_study()
9        computed the wrong minimum data length (which is of course zero for such
10        subpatterns).
11    
12    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13        the pattern is reset in the first branch, pcre_compile() failed with
14        "internal error: code overflow at offset...". This happened only when
15        the reset was to the original external option setting. (An optimization
16        abstracts leading options settings into an external setting, which was the
17        cause of this.)
18    
19    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21        assertion pattern did not match (meaning that the assertion was true), it
22        was incorrectly treated as false if the SKIP had been reached during the
23        matching. This also applied to assertions used as conditions.
24    
25    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
26        assertion subpattern, including such a pattern used as a condition,
27        unpredictable results occurred, instead of the error return
28        PCRE_ERROR_DFA_UITEM.
29    
30    5.  The C++ GlobalReplace function was not working like Perl for the special
31        situation when an empty string is matched. It now does the fancy magic
32        stuff that is necessary.
33    
34    
35    Version 8.00 19-Oct-09
36    ----------------------
37    
38    1.  The table for translating pcre_compile() error codes into POSIX error codes
39        was out-of-date, and there was no check on the pcre_compile() error code
40        being within the table. This could lead to an OK return being given in
41        error.
42    
43    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
44        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
45        in a Windows environment.
46    
47    3.  The pcregrep --count option prints the count for each file even when it is
48        zero, as does GNU grep. However, pcregrep was also printing all files when
49        --files-with-matches was added. Now, when both options are given, it prints
50        counts only for those files that have at least one match. (GNU grep just
51        prints the file name in this circumstance, but including the count seems
52        more useful - otherwise, why use --count?) Also ensured that the
53        combination -clh just lists non-zero counts, with no names.
54    
55    4.  The long form of the pcregrep -F option was incorrectly implemented as
56        --fixed_strings instead of --fixed-strings. This is an incompatible change,
57        but it seems right to fix it, and I didn't think it was worth preserving
58        the old behaviour.
59    
60    5.  The command line items --regex=pattern and --regexp=pattern were not
61        recognized by pcregrep, which required --regex pattern or --regexp pattern
62        (with a space rather than an '='). The man page documented the '=' forms,
63        which are compatible with GNU grep; these now work.
64    
65    6.  No libpcreposix.pc file was created for pkg-config; there was just
66        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
67    
68    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
69        when UCP support is not needed, by modifying the Python script that
70        generates it from Unicode data files. This should not matter if the module
71        is correctly used as a library, but I received one complaint about 50K of
72        unwanted data. My guess is that the person linked everything into his
73        program rather than using a library. Anyway, it does no harm.
74    
75    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
76        was a minimum greater than 1 for a wide character in a possessive
77        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
78        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
79        character. Chaos in the form of incorrect output or a compiling loop could
80        result.
81    
82    9.  The restrictions on what a pattern can contain when partial matching is
83        requested for pcre_exec() have been removed. All patterns can now be
84        partially matched by this function. In addition, if there are at least two
85        slots in the offset vector, the offset of the earliest inspected character
86        for the match and the offset of the end of the subject are set in them when
87        PCRE_ERROR_PARTIAL is returned.
88    
89    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
90        synonymous with PCRE_PARTIAL, for backwards compatibility, and
91        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
92        and may be more useful for multi-segment matching.
93    
94    11. Partial matching with pcre_exec() is now more intuitive. A partial match
95        used to be given if ever the end of the subject was reached; now it is
96        given only if matching could not proceed because another character was
97        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
98        string "Z", which now yields "no match" instead of "partial match". In the
99        case of pcre_dfa_exec(), "no match" is given if every matching path for the
100        final character ended with (*FAIL).
101    
102    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
103        if the pattern had a "must contain" character that was already found in the
104        earlier partial match, unless partial matching was again requested. For
105        example, with the pattern /dog.(body)?/, the "must contain" character is
106        "g". If the first part-match was for the string "dog", restarting with
107        "sbody" failed. This bug has been fixed.
108    
109    13. The string returned by pcre_dfa_exec() after a partial match has been
110        changed so that it starts at the first inspected character rather than the
111        first character of the match. This makes a difference only if the pattern
112        starts with a lookbehind assertion or \b or \B (\K is not supported by
113        pcre_dfa_exec()). It's an incompatible change, but it makes the two
114        matching functions compatible, and I think it's the right thing to do.
115    
116    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
117        so that the demonstration program is easily available in environments where
118        PCRE has not been installed from source.
119    
120    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
121        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
122        library.
123    
124    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
125        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
126        is not the first non-POSIX option to be added. Clearly some people find
127        these options useful.
128    
129    17. If a caller to the POSIX matching function regexec() passes a non-zero
130        value for nmatch with a NULL value for pmatch, the value of
131        nmatch is forced to zero.
132    
133    18. RunGrepTest did not have a test for the availability of the -u option of
134        the diff command, as RunTest does. It now checks in the same way as
135        RunTest, and also checks for the -b option.
136    
137    19. If an odd number of negated classes containing just a single character
138        interposed, within parentheses, between a forward reference to a named
139        subpattern and the definition of the subpattern, compilation crashed with
140        an internal error, complaining that it could not find the referenced
141        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
142        [The bug was that it was starting one character too far in when skipping
143        over the character class, thus treating the ] as data rather than
144        terminating the class. This meant it could skip too much.]
145    
146    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
147        /g option in pcretest when the pattern contains \K, which makes it possible
148        to have an empty string match not at the start, even when the pattern is
149        anchored. Updated pcretest and pcredemo to use this option.
150    
151    21. If the maximum number of capturing subpatterns in a recursion was greater
152        than the maximum at the outer level, the higher number was returned, but
153        with unset values at the outer level. The correct (outer level) value is
154        now given.
155    
156    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
157        PCRE did not set those parentheses (unlike Perl). I have now found a way to
158        make it do so. The string so far is captured, making this feature
159        compatible with Perl.
160    
161    23. The tests have been re-organized, adding tests 11 and 12, to make it
162        possible to check the Perl 5.10 features against Perl 5.10.
163    
164    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
165        pattern matches a fixed length string. PCRE did not allow this; now it
166        does. Neither allows recursion.
167    
168    25. I finally figured out how to implement a request to provide the minimum
169        length of subject string that was needed in order to match a given pattern.
170        (It was back references and recursion that I had previously got hung up
171        on.) This code has now been added to pcre_study(); it finds a lower bound
172        to the length of subject needed. It is not necessarily the greatest lower
173        bound, but using it to avoid searching strings that are too short does give
174        some useful speed-ups. The value is available to calling programs via
175        pcre_fullinfo().
176    
177    26. While implementing 25, I discovered to my embarrassment that pcretest had
178        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
179        study optimizations had never been tested with that matching function.
180        Oops. What is worse, even when it was passed study data, there was a bug in
181        pcre_dfa_exec() that meant it never actually used it. Double oops. There
182        were also very few tests of studied patterns with pcre_dfa_exec().
183    
184    27. If (?| is used to create subpatterns with duplicate numbers, they are now
185        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
186        on the other side of the coin, they are no longer allowed to have different
187        names, because these cannot be distinguished in PCRE, and this has caused
188        confusion. (This is a difference from Perl.)
189    
190    28. When duplicate subpattern names are present (necessarily with different
191        numbers, as required by 27 above), and a test is made by name in a
192        conditional pattern, either for a subpattern having been matched, or for
193        recursion in such a pattern, all the associated numbered subpatterns are
194        tested, and the overall condition is true if the condition is true for any
195        one of them. This is the way Perl works, and is also more like the way
196        testing by number works.
197    
198    
199    Version 7.9 11-Apr-09
200    ---------------------
201    
202    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
203        (pcretest), all targets were linked against these libraries. This included
204        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
205        libraries. This caused unwanted dependencies to be created. This problem
206        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
207        pcretest is linked with readline.
208    
209    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
210        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
211        moved outside it again, because FALSE and TRUE are already defined in AIX,
212        but BOOL is not.
213    
214    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
215        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
216    
217    4.  The pcregrep documentation said spaces were inserted as well as colons (or
218        hyphens) following file names and line numbers when outputting matching
219        lines. This is not true; no spaces are inserted. I have also clarified the
220        wording for the --colour (or --color) option.
221    
222    5.  In pcregrep, when --colour was used with -o, the list of matching strings
223        was not coloured; this is different to GNU grep, so I have changed it to be
224        the same.
225    
226    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
227        each matching line was coloured. Now it goes on to look for further matches
228        of any of the test patterns, which is the same behaviour as GNU grep.
229    
230    7.  A pattern that could match an empty string could cause pcregrep to loop; it
231        doesn't make sense to accept an empty string match in pcregrep, so I have
232        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
233        seems to be how GNU grep behaves.
234    
235    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
236        start or after a newline", because the conditional assertion was not being
237        correctly handled. The rule now is that both the assertion and what follows
238        in the first alternative must satisfy the test.
239    
240    9.  If auto-callout was enabled in a pattern with a conditional group whose
241        condition was an assertion, PCRE could crash during matching, both with
242        pcre_exec() and pcre_dfa_exec().
243    
244    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
245        used for matching.
246    
247    11. Unicode property support in character classes was not working for
248        characters (bytes) greater than 127 when not in UTF-8 mode.
249    
250    12. Added the -M command line option to pcretest.
251    
252    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
253    
254    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
255    
256    16. Added comments and documentation about mis-use of no_arg in the C++
257        wrapper.
258    
259    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
260        from Martin Jerabek that uses macro names for all relevant character and
261        string constants.
262    
263    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
264        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
265        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
266        these, but not everybody uses configure.
267    
268    19. A conditional group that had only one branch was not being correctly
269        recognized as an item that could match an empty string. This meant that an
270        enclosing group might also not be so recognized, causing infinite looping
271        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
272        with the subject "ab", where knowledge that the repeated group can match
273        nothing is needed in order to break the loop.
274    
275    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
276        exec(), but without supplying a callout function, matching went wrong.
277    
278    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
279        leak if the size of the offset vector was greater than 30. When the vector
280        is smaller, the saved offsets during recursion go onto a local stack
281        vector, but for larger vectors malloc() is used. It was failing to free
282        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
283        error, in fact).
284    
285    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
286        heapframe that is used only when UTF-8 support is enabled. This caused no
287        problem, but was untidy.
288    
289    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
290        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
291        included within another project.
292    
293    24. Steven Van Ingelgem's patches to add more options to the CMake support,
294        slightly modified by me:
295    
296          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
297              not building pcregrep.
298    
299          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
300              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
301    
302    25. Forward references, both numeric and by name, in patterns that made use of
303        duplicate group numbers, could behave incorrectly or give incorrect errors,
304        because when scanning forward to find the reference group, PCRE was not
305        taking into account the duplicate group numbers. A pattern such as
306        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
307    
308    26. Changed a few more instances of "const unsigned char *" to USPTR, making
309        the feature of a custom pointer more persuasive (as requested by a user).
310    
311    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
312        pcretest.c, inside #ifndefs, because it seems they are sometimes already
313        pre-defined.
314    
315    28. Added support for (*UTF8) at the start of a pattern.
316    
317    29. Arrange for flags added by the "release type" setting in CMake to be shown
318        in the configuration summary.
319    
320    
321    Version 7.8 05-Sep-08
322    ---------------------
323    
324    1.  Replaced UCP searching code with optimized version as implemented for Ad
325        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
326        stage table and inline lookup instead of a function, giving speed ups of 2
327        to 5 times on some simple patterns that I tested. Permission was given to
328        distribute the MultiStage2.py script that generates the tables (it's not in
329        the tarball, but is in the Subversion repository).
330    
331    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
332        scripts.
333    
334    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
335        a group with a zero qualifier. The result of the study could be incorrect,
336        or the function might crash, depending on the pattern.
337    
338    4.  Caseless matching was not working for non-ASCII characters in back
339        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
340        It now works when Unicode Property Support is available.
341    
342    5.  In pcretest, an escape such as \x{de} in the data was always generating
343        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
344        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
345        truncation.
346    
347    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
348    
349    7.  Added two (int) casts to pcregrep when printing the difference of two
350        pointers, in case they are 64-bit values.
351    
352    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
353        test 2 if it fails.
354    
355    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
356        and a #define of that name to empty if it is not externally set. This is to
357        allow users of MSVC to set it if necessary.
358    
359    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
360        the convenience functions in the pcre_get.c source file.
361    
362    11. An option change at the start of a pattern that had top-level alternatives
363        could cause overwriting and/or a crash. This command provoked a crash in
364        some environments:
365    
366          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
367    
368        This potential security problem was recorded as CVE-2008-2371.
369    
370    12. For a pattern where the match had to start at the beginning or immediately
371        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
372        pcre_dfa_exec() could read past the end of the passed subject if there was
373        no match. To help with detecting such bugs (e.g. with valgrind), I modified
374        pcretest so that it places the subject at the end of its malloc-ed buffer.
375    
376    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
377        exec() might read past the end of the data buffer in UTF-8 mode.
378    
379    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
380        the data contained the byte 0x85 as part of a UTF-8 character within its
381        first line. This applied both to normal and DFA matching.
382    
383    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
384        /^[^d]*?$/8 failed to match "abc".
385    
386    16. Added a missing copyright notice to pcrecpp_internal.h.
387    
388    17. Make it more clear in the documentation that values returned from
389        pcre_exec() in ovector are byte offsets, not character counts.
390    
391    18. Tidied a few places to stop certain compilers from issuing warnings.
392    
393    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
394        supplied by Stefan Weber. I made a further small update for 7.8 because
395        there is a change of source arrangements: the pcre_searchfuncs.c module is
396        replaced by pcre_ucd.c.
397    
398    
399    Version 7.7 07-May-08
400    ---------------------
401    
402    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
403        a string to a long long, pretend we don't even have a long long." This is
404        done by checking for the strtoq, strtoll, and _strtoi64 functions.
405    
406    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
407        pre-7.6 versions, which defined a global no_arg variable instead of putting
408        it in the RE class. (See also #8 below.)
409    
410    3.  Remove a line of dead code, identified by coverity and reported by Nuno
411        Lopes.
412    
413    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
414    
415        (1) The include/exclude patterns were being applied to the whole pathnames
416            of files, instead of just to the final components.
417    
418        (2) If there was more than one level of directory, the subdirectories were
419            skipped unless they satisfied the include/exclude conditions. This is
420            inconsistent with GNU grep (and could even be seen as contrary to the
421            pcregrep specification - which I improved to make it absolutely clear).
422            The action now is always to scan all levels of directory, and just
423            apply the include/exclude patterns to regular files.
424    
425    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
426        --exclude_dir in the tests to avoid scanning .svn directories.
427    
428    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
429        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
430        doesn't support NULs in patterns.
431    
432    7.  Added some missing "const"s to declarations of static tables in
433        pcre_compile.c and pcre_dfa_exec.c.
434    
435    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
436        caused by fix #2  above. (Subsequently also a second patch to fix the
437        first patch. And a third patch - this was a messy problem.)
438    
439    9.  Applied Craig's patch to remove the use of push_back().
440    
441    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
442        matching function regexec().
443    
444    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
445        which, however, unlike Perl's \g{...}, are subroutine calls, not back
446        references. PCRE supports relative numbers with this syntax (I don't think
447        Oniguruma does).
448    
449    12. Previously, a group with a zero repeat such as (...){0} was completely
450        omitted from the compiled regex. However, this means that if the group
451        was called as a subroutine from elsewhere in the pattern, things went wrong
452        (an internal error was given). Such groups are now left in the compiled
453        pattern, with a new opcode that causes them to be skipped at execution
454        time.
455    
456    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
457        to the way PCRE behaves:
458    
459        (a) A lone ] character is dis-allowed (Perl treats it as data).
460    
461        (b) A back reference to an unmatched subpattern matches an empty string
462            (Perl fails the current match path).
463    
464        (c) A data ] in a character class must be notated as \] because if the
465            first data character in a class is ], it defines an empty class. (In
466            Perl it is not possible to have an empty class.) The empty class []
467            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
468            The negative empty class [^] matches any one character, independently
469            of the DOTALL setting.
470    
471    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
472        non-existent subpattern following a character class starting with ']' and
473        containing () gave an internal compiling error instead of "reference to
474        non-existent subpattern". Fortunately, when the pattern did exist, the
475        compiled code was correct. (When scanning forwards to check for the
476        existencd of the subpattern, it was treating the data ']' as terminating
477        the class, so got the count wrong. When actually compiling, the reference
478        was subsequently set up correctly.)
479    
480    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
481        it was being rejected as not supported by pcre_dfa_exec(), even though
482        other assertions are supported. I have made pcre_dfa_exec() support
483        (*FAIL).
484    
485    16. The implementation of 13c above involved the invention of a new opcode,
486        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
487        cannot be changed at match time, I realized I could make a small
488        improvement to matching performance by compiling OP_ALLANY instead of
489        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
490        on the OP_ANY path.
491    
492    17. Compiling pcretest on Windows with readline support failed without the
493        following two fixes: (1) Make the unistd.h include conditional on
494        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
495    
496    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
497        ncurses library to be included for pcretest when ReadLine support is
498        requested, but also to allow for it to be overridden. This patch came from
499        Daniel Bergström.
500    
501    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
502        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
503        any errors with the current Unicode tables. Thanks to Peter Kankowski for
504        spotting this.
505    
506    
507    Version 7.6 28-Jan-08
508    ---------------------
509    
510    1.  A character class containing a very large number of characters with
511        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
512        overflow.
513    
514    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
515        HAVE_LONG_LONG is not defined.
516    
517    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
518        bring them up to date and include new features. This patch includes:
519    
520        - Fixed PH's badly added libz and libbz2 support.
521        - Fixed a problem with static linking.
522        - Added pcredemo. [But later removed - see 7 below.]
523        - Fixed dftables problem and added an option.
524        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
525            HAVE_LONG_LONG.
526        - Added readline support for pcretest.
527        - Added an listing of the option settings after cmake has run.
528    
529    4.  A user submitted a patch to Makefile that makes it easy to create
530        "pcre.dll" under mingw when using Configure/Make. I added stuff to
531        Makefile.am that cause it to include this special target, without
532        affecting anything else. Note that the same mingw target plus all
533        the other distribution libraries and programs are now supported
534        when configuring with CMake (see 6 below) instead of with
535        Configure/Make.
536    
537    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
538        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
539        exported in the Windows port". It has not yet been confirmed that the patch
540        solves the problem, but it does no harm.
541    
542    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
543        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
544        with CMake, and also correct the comment about stack recursion.
545    
546    7.  Remove the automatic building of pcredemo from the ./configure system and
547        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
548        of a program that users should build themselves after PCRE is installed, so
549        building it automatically is not really right. What is more, it gave
550        trouble in some build environments.
551    
552    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
553    
554    
555    Version 7.5 10-Jan-08
556    ---------------------
557    
558    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
559        values in parens when parsing an RE using the C++ wrapper."
560    
561    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
562        Characters greater than 255 were excluded from the class instead of being
563        included.
564    
565    3.  The same bug as (2) above applied to negated POSIX classes such as
566        [:^space:].
567    
568    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
569        defined or documented. It seems to have been a typo for PCRE_STATIC, so
570        I have changed it.
571    
572    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
573        first named subpattern) and a construct such as (?&a) would reference the
574        first named subpattern whose name started with "a" (in other words, the
575        length check was missing). Both these problems are fixed. "Subpattern name
576        expected" is now given for (?&) (a zero-length name), and this patch also
577        makes it give the same error for \k'' (previously it complained that that
578        was a reference to a non-existent subpattern).
579    
580    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
581        this is right because (?- can be followed by option settings as well as by
582        digits. I have, however, made the messages clearer.
583    
584    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
585        than the number used in the conditional) now cause a compile-time error.
586        This is actually not compatible with Perl, which accepts such patterns, but
587        treats the conditional as always being FALSE (as PCRE used to), but it
588        seems to me that giving a diagnostic is better.
589    
590    8.  Change "alphameric" to the more common word "alphanumeric" in comments
591        and messages.
592    
593    9.  Fix two occurrences of "backslash" in comments that should have been
594        "backspace".
595    
596    10. Remove two redundant lines of code that can never be obeyed (their function
597        was moved elsewhere).
598    
599    11. The program that makes PCRE's Unicode character property table had a bug
600        which caused it to generate incorrect table entries for sequences of
601        characters that have the same character type, but are in different scripts.
602        It amalgamated them into a single range, with the script of the first of
603        them. In other words, some characters were in the wrong script. There were
604        thirteen such cases, affecting characters in the following ranges:
605    
606          U+002b0 - U+002c1
607          U+0060c - U+0060d
608          U+0061e - U+00612
609          U+0064b - U+0065e
610          U+0074d - U+0076d
611          U+01800 - U+01805
612          U+01d00 - U+01d77
613          U+01d9b - U+01dbf
614          U+0200b - U+0200f
615          U+030fc - U+030fe
616          U+03260 - U+0327f
617          U+0fb46 - U+0fbb1
618          U+10450 - U+1049d
619    
620    12. The -o option (show only the matching part of a line) for pcregrep was not
621        compatible with GNU grep in that, if there was more than one match in a
622        line, it showed only the first of them. It now behaves in the same way as
623        GNU grep.
624    
625    13. If the -o and -v options were combined for pcregrep, it printed a blank
626        line for every non-matching line. GNU grep prints nothing, and pcregrep now
627        does the same. The return code can be used to tell if there were any
628        non-matching lines.
629    
630    14. Added --file-offsets and --line-offsets to pcregrep.
631    
632    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
633        infinitely looping recursion. The bug was that positive lookaheads were not
634        being skipped when checking for a possible empty match (negative lookaheads
635        and both kinds of lookbehind were skipped).
636    
637    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
638        inclusion of <windows.h> to before rather than after the definition of
639        INVALID_FILE_ATTRIBUTES (patch from David Byron).
640    
641    17. Specifying a possessive quantifier with a specific limit for a Unicode
642        character property caused pcre_compile() to compile bad code, which led at
643        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
644        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
645        caused the error; without that there was no problem.
646    
647    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
648    
649    19. Added --enable-pcretest-libreadline.
650    
651    20. In pcrecpp.cc, the variable 'count' was incremented twice in
652        RE::GlobalReplace(). As a result, the number of replacements returned was
653        double what it should be. I removed one of the increments, but Craig sent a
654        later patch that removed the other one (the right fix) and added unit tests
655        that check the return values (which was not done before).
656    
657    21. Several CMake things:
658    
659        (1) Arranged that, when cmake is used on Unix, the libraries end up with
660            the names libpcre and libpcreposix, not just pcre and pcreposix.
661    
662        (2) The above change means that pcretest and pcregrep are now correctly
663            linked with the newly-built libraries, not previously installed ones.
664    
665        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
666    
667    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
668        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
669        UTF-8 newline character). The key issue is that the pattern starts .*;
670        this means that the match must be either at the beginning, or after a
671        newline. The bug was in the code for advancing after a failed match and
672        checking that the new position followed a newline. It was not taking
673        account of UTF-8 characters correctly.
674    
675    23. PCRE was behaving differently from Perl in the way it recognized POSIX
676        character classes. PCRE was not treating the sequence [:...:] as a
677        character class unless the ... were all letters. Perl, however, seems to
678        allow any characters between [: and :], though of course it rejects as
679        unknown any "names" that contain non-letters, because all the known class
680        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
681        for example, whereas PCRE did not - it did not recognize a POSIX character
682        class. This seemed a bit dangerous, so the code has been changed to be
683        closer to Perl. The behaviour is not identical to Perl, because PCRE will
684        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
685        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
686        Perl does, and where it didn't before.
687    
688    24. Rewrite so as to remove the single use of %n from pcregrep because in some
689        Windows environments %n is disabled by default.
690    
691    
692    Version 7.4 21-Sep-07
693    ---------------------
694    
695    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
696        means that a class such as [\s] counted as "explicit reference to CR or
697        LF". That isn't really right - the whole point of the change was to try to
698        help when there was an actual mention of one of the two characters. So now
699        the change happens only if \r or \n (or a literal CR or LF) character is
700        encountered.
701    
702    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
703        of both had grown to the point where there were only 3 bits left.
704        Fortunately, there was spare space in the data structure, and so I have
705        moved the internal flags into a new 16-bit field to free up more option
706        bits.
707    
708    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
709        but did not set the internal JCHANGED flag - either of these is enough to
710        control the way the "get" function works - but the PCRE_INFO_JCHANGED
711        facility is supposed to tell if (?J) was ever used, so now (?J) at the
712        start sets both bits.
713    
714    4.  Added options (at build time, compile time, exec time) to change \R from
715        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
716    
717    5.  doc/pcresyntax.html was missing from the distribution.
718    
719    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
720        compatibility, even though it is no longer used.
721    
722    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
723        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
724        windows.h file is present (where different names are used). [This was
725        reversed later after testing - see 16 below.]
726    
727    8.  Changed all #include <config.h> to #include "config.h". There were also
728        some further <pcre.h> cases that I changed to "pcre.h".
729    
730    9.  When pcregrep was used with the --colour option, it missed the line ending
731        sequence off the lines that it output.
732    
733    10. It was pointed out to me that arrays of string pointers cause lots of
734        relocations when a shared library is dynamically loaded. A technique of
735        using a single long string with a table of offsets can drastically reduce
736        these. I have refactored PCRE in four places to do this. The result is
737        dramatic:
738    
739          Originally:                          290
740          After changing UCP table:            187
741          After changing error message table:   43
742          After changing table of "verbs"       36
743          After changing table of Posix names   22
744    
745        Thanks to the folks working on Gregex for glib for this insight.
746    
747    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
748        unicode-properties was also set.
749    
750    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
751    
752    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
753        checked only for CRLF.
754    
755    14. Added casts to pcretest.c to avoid compiler warnings.
756    
757    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
758    
759    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
760        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
761        entirely. This removes changes made in 7 above.
762    
763    17. The CMake files have been updated, and there is now more information about
764        building with CMake in the NON-UNIX-USE document.
765    
766    
767    Version 7.3 28-Aug-07
768    ---------------------
769    
770     1. In the rejigging of the build system that eventually resulted in 7.1, the
771        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
772        brackets there is not right, since it causes compilers to look for an
773        installed pcre.h, not the version that is in the source that is being
774        compiled (which of course may be different). I have changed it back to:
775    
776          #include "pcre.h"
777    
778        I have a vague recollection that the change was concerned with compiling in
779        different directories, but in the new build system, that is taken care of
780        by the VPATH setting the Makefile.
781    
782     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
783        when the subject happened to end in the byte 0x85 (e.g. if the last
784        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
785        characters but of course it shouldn't be taken as a newline when it is part
786        of another character. The bug was that, for an unlimited repeat of . in
787        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
788        characters when looking for a newline.
789    
790     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
791    
792     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
793        in debug output.
794    
795     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
796        long printing in the pcrecpp unittest when running under MinGW.
797    
798     6. ESC_K was left out of the EBCDIC table.
799    
800     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
801        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
802        limit also applies to "virtual nesting" when a pattern is recursive, and in
803        this case 1000 isn't so big. I have been able to remove this limit at the
804        expense of backing off one optimization in certain circumstances. Normally,
805        when pcre_exec() would call its internal match() function recursively and
806        immediately return the result unconditionally, it uses a "tail recursion"
807        feature to save stack. However, when a subpattern that can match an empty
808        string has an unlimited repetition quantifier, it no longer makes this
809        optimization. That gives it a stack frame in which to save the data for
810        checking that an empty string has been matched. Previously this was taken
811        from the 1000-entry workspace that had been reserved. So now there is no
812        explicit limit, but more stack is used.
813    
814     8. Applied Daniel's patches to solve problems with the import/export magic
815        syntax that is required for Windows, and which was going wrong for the
816        pcreposix and pcrecpp parts of the library. These were overlooked when this
817        problem was solved for the main library.
818    
819     9. There were some crude static tests to avoid integer overflow when computing
820        the size of patterns that contain repeated groups with explicit upper
821        limits. As the maximum quantifier is 65535, the maximum group length was
822        set at 30,000 so that the product of these two numbers did not overflow a
823        32-bit integer. However, it turns out that people want to use groups that
824        are longer than 30,000 bytes (though not repeat them that many times).
825        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
826        made it possible to implement the integer overflow checks in a much more
827        dynamic way, which I have now done. The artificial limitation on group
828        length has been removed - we now have only the limit on the total length of
829        the compiled pattern, which depends on the LINK_SIZE setting.
830    
831    10. Fixed a bug in the documentation for get/copy named substring when
832        duplicate names are permitted. If none of the named substrings are set, the
833        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
834        empty string.
835    
836    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
837        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
838        because the ] is interpreted as the first data character and the
839        terminating ] is not found. PCRE has been made compatible with Perl in this
840        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
841        cause memory overwriting.
842    
843    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
844        string has been matched (to stop an infinite loop). It was not recognizing
845        a conditional subpattern that could match an empty string if that
846        subpattern was within another subpattern. For example, it looped when
847        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
848        condition was not nested. This bug has been fixed.
849    
850    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
851        past the start of the subject in the presence of bytes with the top bit
852        set, for example "\x8aBCD".
853    
854    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
855        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
856    
857    14. Optimized (?!) to (*FAIL).
858    
859    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
860        This restricts code points to be within the range 0 to 0x10FFFF, excluding
861        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
862        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
863        does: it's just the validity check that is more restrictive.
864    
865    16. Inserted checks for integer overflows during escape sequence (backslash)
866        processing, and also fixed erroneous offset values for syntax errors during
867        backslash processing.
868    
869    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
870        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
871    
872    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
873        caused an overrun.
874    
875    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
876        something other than just ASCII characters) inside a group that had an
877        unlimited repeat caused a loop at compile time (while checking to see
878        whether the group could match an empty string).
879    
880    20. Debugging a pattern containing \p or \P could cause a crash. For example,
881        [\P{Any}] did so. (Error in the code for printing property names.)
882    
883    21. An orphan \E inside a character class could cause a crash.
884    
885    22. A repeated capturing bracket such as (A)? could cause a wild memory
886        reference during compilation.
887    
888    23. There are several functions in pcre_compile() that scan along a compiled
889        expression for various reasons (e.g. to see if it's fixed length for look
890        behind). There were bugs in these functions when a repeated \p or \P was
891        present in the pattern. These operators have additional parameters compared
892        with \d, etc, and these were not being taken into account when moving along
893        the compiled data. Specifically:
894    
895        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
896            length.
897    
898        (b) An item such as \pL+ within a repeated group could cause crashes or
899            loops.
900    
901        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
902            "reference to non-existent subpattern" error.
903    
904        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
905    
906    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
907        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
908    
909    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
910    
911    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
912        character were causing crashes (broken optimization).
913    
914    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
915        \p or \P) caused a compile-time loop.
916    
917    28. More problems have arisen in unanchored patterns when CRLF is a valid line
918        break. For example, the unstudied pattern [\r\n]A does not match the string
919        "\r\nA" because change 7.0/46 below moves the current point on by two
920        characters after failing to match at the start. However, the pattern \nA
921        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
922        the same is true. There doesn't seem any very clean way out of this, but
923        what I have chosen to do makes the common cases work: PCRE now takes note
924        of whether there can be an explicit match for \r or \n anywhere in the
925        pattern, and if so, 7.0/46 no longer applies. As part of this change,
926        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
927        pattern has explicit CR or LF references.
928    
929    29. Added (*CR) etc for changing newline setting at start of pattern.
930    
931    
932    Version 7.2 19-Jun-07
933    ---------------------
934    
935     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
936        which is apparently normally available under Windows.
937    
938     2. Re-jig the pcregrep tests with different newline settings in an attempt
939        to make them independent of the local environment's newline setting.
940    
941     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
942    
943     4. Some of the "internals" tests were previously cut out when the link size
944        was not 2, because the output contained actual offsets. The recent new
945        "Z" feature of pcretest means that these can be cut out, making the tests
946        usable with all link sizes.
947    
948     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
949        stack recursion. This gives a massive performance boost under BSD, but just
950        a small improvement under Linux. However, it saves one field in the frame
951        in all cases.
952    
953     6. Added more features from the forthcoming Perl 5.10:
954    
955        (a) (?-n) (where n is a string of digits) is a relative subroutine or
956            recursion call. It refers to the nth most recently opened parentheses.
957    
958        (b) (?+n) is also a relative subroutine call; it refers to the nth next
959            to be opened parentheses.
960    
961        (c) Conditions that refer to capturing parentheses can be specified
962            relatively, for example, (?(-2)... or (?(+3)...
963    
964        (d) \K resets the start of the current match so that everything before
965            is not part of it.
966    
967        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
968    
969        (f) \g{name} is another synonym - part of Perl 5.10's unification of
970            reference syntax.
971    
972        (g) (?| introduces a group in which the numbering of parentheses in each
973            alternative starts with the same number.
974    
975        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
976    
977     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
978        PCRE_INFO_JCHANGED.
979    
980     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
981        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
982        for detecting groups that can match an empty string.
983    
984     9. A pattern with a very large number of alternatives (more than several
985        hundred) was running out of internal workspace during the pre-compile
986        phase, where pcre_compile() figures out how much memory will be needed. A
987        bit of new cunning has reduced the workspace needed for groups with
988        alternatives. The 1000-alternative test pattern now uses 12 bytes of
989        workspace instead of running out of the 4096 that are available.
990    
991    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
992    
993    11. Applied patch from Google to remove an optimization that didn't quite work.
994        The report of the bug said:
995    
996          pcrecpp::RE("a*").FullMatch("aaa") matches, while
997          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
998          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
999    
1000    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1001        it matched the wrong number of bytes.
1002    
1003    
1004    Version 7.1 24-Apr-07
1005  ---------------------  ---------------------
1006    
1007   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one

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