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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 8.10 03 May-2010
5    ------------------------
6    
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
9    
10    2.  (*ACCEPT) was not working when inside an atomic group.
11    
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
15    
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
19    
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
22    
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
28    
29    7.  Minor change to pcretest.c to avoid a compiler warning.
30    
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
39    
40    10. Added --line-buffered to pcregrep.
41    
42    
43    Version 8.02 19-Mar-2010
44    ------------------------
45    
46    1.  The Unicode data tables have been updated to Unicode 5.2.0.
47    
48    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
49        configured.
50    
51    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
52        original author of that file, following a query about its status.
53    
54    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
55        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
56    
57    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
58        quantifier applied to a forward-referencing subroutine call, could compile
59        incorrect code or give the error "internal error: previously-checked
60        referenced subpattern not found".
61    
62    6.  Both MS Visual Studio and Symbian OS have problems with initializing
63        variables to point to external functions. For these systems, therefore,
64        pcre_malloc etc. are now initialized to local functions that call the
65        relevant global functions.
66    
67    7.  There were two entries missing in the vectors called coptable and poptable
68        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
69        I've fixed the data, and added a kludgy way of testing at compile time that
70        the lengths are correct (equal to the number of opcodes).
71    
72    8.  Following on from 7, I added a similar kludge to check the length of the
73        eint vector in pcreposix.c.
74    
75    9.  Error texts for pcre_compile() are held as one long string to avoid too
76        much relocation at load time. To find a text, the string is searched,
77        counting zeros. There was no check for running off the end of the string,
78        which could happen if a new error number was added without updating the
79        string.
80    
81    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
82    
83    11. \K was not working if it appeared in an atomic group or in a group that
84        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
85        \K is "not well defined" if used in an assertion. PCRE now accepts it if
86        the assertion is positive, but not if it is negative.
87    
88    12. Change 11 fortuitously reduced the size of the stack frame used in the
89        "match()" function of pcre_exec.c by one pointer. Forthcoming
90        implementation of support for (*MARK) will need an extra pointer on the
91        stack; I have reserved it now, so that the stack frame size does not
92        decrease.
93    
94    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
95        item in branch that calls a recursion is a subroutine call - as in the
96        second branch in the above example - was incorrectly given the compile-
97        time error "recursive call could loop indefinitely" because pcre_compile()
98        was not correctly checking the subroutine for matching a non-empty string.
99    
100    14. The checks for overrunning compiling workspace could trigger after an
101        overrun had occurred. This is a "should never occur" error, but it can be
102        triggered by pathological patterns such as hundreds of nested parentheses.
103        The checks now trigger 100 bytes before the end of the workspace.
104    
105    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
106    
107    
108    Version 8.01 19-Jan-2010
109    ------------------------
110    
111    1.  If a pattern contained a conditional subpattern with only one branch (in
112        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
113        computed the wrong minimum data length (which is of course zero for such
114        subpatterns). This could cause incorrect "no match" results.
115    
116    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
117        the pattern is reset in the first branch, pcre_compile() failed with
118        "internal error: code overflow at offset...". This happened only when
119        the reset was to the original external option setting. (An optimization
120        abstracts leading options settings into an external setting, which was the
121        cause of this.)
122    
123    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
124        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
125        assertion pattern did not match (meaning that the assertion was true), it
126        was incorrectly treated as false if the SKIP had been reached during the
127        matching. This also applied to assertions used as conditions.
128    
129    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
130        assertion subpattern, including such a pattern used as a condition,
131        unpredictable results occurred, instead of the error return
132        PCRE_ERROR_DFA_UITEM.
133    
134    5.  The C++ GlobalReplace function was not working like Perl for the special
135        situation when an empty string is matched. It now does the fancy magic
136        stuff that is necessary.
137    
138    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
139        removed. (These were left over from very, very early versions of PCRE.)
140    
141    7.  Some cosmetic changes to the code to make life easier when compiling it
142        as part of something else:
143    
144        (a) Change DEBUG to PCRE_DEBUG.
145    
146        (b) In pcre_compile(), rename the member of the "branch_chain" structure
147            called "current" as "current_branch", to prevent a collision with the
148            Linux macro when compiled as a kernel module.
149    
150        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
151            prevent a collision with the Linux macro when compiled as a kernel
152            module.
153    
154    8.  In pcre_compile() there are some checks for integer overflows that used to
155        cast potentially large values to (double). This has been changed to that
156        when building, a check for int64_t is made, and if it is found, it is used
157        instead, thus avoiding the use of floating point arithmetic. (There is no
158        other use of FP in PCRE.) If int64_t is not found, the fallback is to
159        double.
160    
161    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
162        2005 (difference between two addresses compared to an unsigned value).
163    
164    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
165        custom one, because of the following reported problem in Windows:
166    
167          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
168              under Win32.
169          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
170              therefore missing the function definition.
171          - The compiler thus generates a "C" signature for the test function.
172          - The linker fails to find the "C" function.
173          - PCRE fails to configure if asked to do so against libbz2.
174    
175    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
176        messages were output:
177    
178          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
179          rerunning libtoolize, to keep the correct libtool macros in-tree.
180          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
181    
182        I have done both of these things.
183    
184    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
185        most of the time, it *can* run out if it is given a pattern that contains a
186        runaway infinite recursion. I updated the discussion in the pcrestack man
187        page.
188    
189    13. Now that we have gone to the x.xx style of version numbers, the minor
190        version may start with zero. Using 08 or 09 is a bad idea because users
191        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
192        interpreted as invalid octal numbers. I've updated the previous comment in
193        configure.ac, and also added a check that gives an error if 08 or 09 are
194        used.
195    
196    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
197        causing partial matching to fail when the end of the subject matched \W
198        in a UTF-8 pattern where \W was quantified with a minimum of 3.
199    
200    15. There were some discrepancies between the declarations in pcre_internal.h
201        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
202        their definitions. The declarations used "const uschar *" and the
203        definitions used USPTR. Even though USPTR is normally defined as "const
204        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
205        reported that: "This difference in casting confuses some C++ compilers, for
206        example, SunCC recognizes above declarations as different functions and
207        generates broken code for hbpcre." I have changed the declarations to use
208        USPTR.
209    
210    16. GNU libtool is named differently on some systems. The autogen.sh script now
211        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
212        (FreeBSD).
213    
214    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
215        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
216        comment: "Figure out how to create a longlong from a string: strtoll and
217        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
218        instance, but it only takes 2 args instead of 3!"
219    
220    18. A subtle bug concerned with back references has been fixed by a change of
221        specification, with a corresponding code fix. A pattern such as
222        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
223        refers, was giving matches when it shouldn't. For example, xa=xaaa would
224        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
225        same bug. Such groups have to be quantified to be useful, or contained
226        inside another quantified group. (If there's no repetition, the reference
227        can never match.) The problem arises because, having left the group and
228        moved on to the rest of the pattern, a later failure that backtracks into
229        the group uses the captured value from the final iteration of the group
230        rather than the correct earlier one. I have fixed this in PCRE by forcing
231        any group that contains a reference to itself to be an atomic group; that
232        is, there cannot be any backtracking into it once it has completed. This is
233        similar to recursive and subroutine calls.
234    
235    
236    Version 8.00 19-Oct-09
237    ----------------------
238    
239    1.  The table for translating pcre_compile() error codes into POSIX error codes
240        was out-of-date, and there was no check on the pcre_compile() error code
241        being within the table. This could lead to an OK return being given in
242        error.
243    
244    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
245        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
246        in a Windows environment.
247    
248    3.  The pcregrep --count option prints the count for each file even when it is
249        zero, as does GNU grep. However, pcregrep was also printing all files when
250        --files-with-matches was added. Now, when both options are given, it prints
251        counts only for those files that have at least one match. (GNU grep just
252        prints the file name in this circumstance, but including the count seems
253        more useful - otherwise, why use --count?) Also ensured that the
254        combination -clh just lists non-zero counts, with no names.
255    
256    4.  The long form of the pcregrep -F option was incorrectly implemented as
257        --fixed_strings instead of --fixed-strings. This is an incompatible change,
258        but it seems right to fix it, and I didn't think it was worth preserving
259        the old behaviour.
260    
261    5.  The command line items --regex=pattern and --regexp=pattern were not
262        recognized by pcregrep, which required --regex pattern or --regexp pattern
263        (with a space rather than an '='). The man page documented the '=' forms,
264        which are compatible with GNU grep; these now work.
265    
266    6.  No libpcreposix.pc file was created for pkg-config; there was just
267        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
268    
269    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
270        when UCP support is not needed, by modifying the Python script that
271        generates it from Unicode data files. This should not matter if the module
272        is correctly used as a library, but I received one complaint about 50K of
273        unwanted data. My guess is that the person linked everything into his
274        program rather than using a library. Anyway, it does no harm.
275    
276    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
277        was a minimum greater than 1 for a wide character in a possessive
278        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
279        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
280        character. Chaos in the form of incorrect output or a compiling loop could
281        result.
282    
283    9.  The restrictions on what a pattern can contain when partial matching is
284        requested for pcre_exec() have been removed. All patterns can now be
285        partially matched by this function. In addition, if there are at least two
286        slots in the offset vector, the offset of the earliest inspected character
287        for the match and the offset of the end of the subject are set in them when
288        PCRE_ERROR_PARTIAL is returned.
289    
290    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
291        synonymous with PCRE_PARTIAL, for backwards compatibility, and
292        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
293        and may be more useful for multi-segment matching.
294    
295    11. Partial matching with pcre_exec() is now more intuitive. A partial match
296        used to be given if ever the end of the subject was reached; now it is
297        given only if matching could not proceed because another character was
298        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
299        string "Z", which now yields "no match" instead of "partial match". In the
300        case of pcre_dfa_exec(), "no match" is given if every matching path for the
301        final character ended with (*FAIL).
302    
303    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
304        if the pattern had a "must contain" character that was already found in the
305        earlier partial match, unless partial matching was again requested. For
306        example, with the pattern /dog.(body)?/, the "must contain" character is
307        "g". If the first part-match was for the string "dog", restarting with
308        "sbody" failed. This bug has been fixed.
309    
310    13. The string returned by pcre_dfa_exec() after a partial match has been
311        changed so that it starts at the first inspected character rather than the
312        first character of the match. This makes a difference only if the pattern
313        starts with a lookbehind assertion or \b or \B (\K is not supported by
314        pcre_dfa_exec()). It's an incompatible change, but it makes the two
315        matching functions compatible, and I think it's the right thing to do.
316    
317    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
318        so that the demonstration program is easily available in environments where
319        PCRE has not been installed from source.
320    
321    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
322        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
323        library.
324    
325    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
326        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
327        is not the first non-POSIX option to be added. Clearly some people find
328        these options useful.
329    
330    17. If a caller to the POSIX matching function regexec() passes a non-zero
331        value for nmatch with a NULL value for pmatch, the value of
332        nmatch is forced to zero.
333    
334    18. RunGrepTest did not have a test for the availability of the -u option of
335        the diff command, as RunTest does. It now checks in the same way as
336        RunTest, and also checks for the -b option.
337    
338    19. If an odd number of negated classes containing just a single character
339        interposed, within parentheses, between a forward reference to a named
340        subpattern and the definition of the subpattern, compilation crashed with
341        an internal error, complaining that it could not find the referenced
342        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
343        [The bug was that it was starting one character too far in when skipping
344        over the character class, thus treating the ] as data rather than
345        terminating the class. This meant it could skip too much.]
346    
347    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
348        /g option in pcretest when the pattern contains \K, which makes it possible
349        to have an empty string match not at the start, even when the pattern is
350        anchored. Updated pcretest and pcredemo to use this option.
351    
352    21. If the maximum number of capturing subpatterns in a recursion was greater
353        than the maximum at the outer level, the higher number was returned, but
354        with unset values at the outer level. The correct (outer level) value is
355        now given.
356    
357    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
358        PCRE did not set those parentheses (unlike Perl). I have now found a way to
359        make it do so. The string so far is captured, making this feature
360        compatible with Perl.
361    
362    23. The tests have been re-organized, adding tests 11 and 12, to make it
363        possible to check the Perl 5.10 features against Perl 5.10.
364    
365    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
366        pattern matches a fixed length string. PCRE did not allow this; now it
367        does. Neither allows recursion.
368    
369    25. I finally figured out how to implement a request to provide the minimum
370        length of subject string that was needed in order to match a given pattern.
371        (It was back references and recursion that I had previously got hung up
372        on.) This code has now been added to pcre_study(); it finds a lower bound
373        to the length of subject needed. It is not necessarily the greatest lower
374        bound, but using it to avoid searching strings that are too short does give
375        some useful speed-ups. The value is available to calling programs via
376        pcre_fullinfo().
377    
378    26. While implementing 25, I discovered to my embarrassment that pcretest had
379        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
380        study optimizations had never been tested with that matching function.
381        Oops. What is worse, even when it was passed study data, there was a bug in
382        pcre_dfa_exec() that meant it never actually used it. Double oops. There
383        were also very few tests of studied patterns with pcre_dfa_exec().
384    
385    27. If (?| is used to create subpatterns with duplicate numbers, they are now
386        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
387        on the other side of the coin, they are no longer allowed to have different
388        names, because these cannot be distinguished in PCRE, and this has caused
389        confusion. (This is a difference from Perl.)
390    
391    28. When duplicate subpattern names are present (necessarily with different
392        numbers, as required by 27 above), and a test is made by name in a
393        conditional pattern, either for a subpattern having been matched, or for
394        recursion in such a pattern, all the associated numbered subpatterns are
395        tested, and the overall condition is true if the condition is true for any
396        one of them. This is the way Perl works, and is also more like the way
397        testing by number works.
398    
399    
400    Version 7.9 11-Apr-09
401    ---------------------
402    
403    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
404        (pcretest), all targets were linked against these libraries. This included
405        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
406        libraries. This caused unwanted dependencies to be created. This problem
407        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
408        pcretest is linked with readline.
409    
410    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
411        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
412        moved outside it again, because FALSE and TRUE are already defined in AIX,
413        but BOOL is not.
414    
415    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
416        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
417    
418    4.  The pcregrep documentation said spaces were inserted as well as colons (or
419        hyphens) following file names and line numbers when outputting matching
420        lines. This is not true; no spaces are inserted. I have also clarified the
421        wording for the --colour (or --color) option.
422    
423    5.  In pcregrep, when --colour was used with -o, the list of matching strings
424        was not coloured; this is different to GNU grep, so I have changed it to be
425        the same.
426    
427    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
428        each matching line was coloured. Now it goes on to look for further matches
429        of any of the test patterns, which is the same behaviour as GNU grep.
430    
431    7.  A pattern that could match an empty string could cause pcregrep to loop; it
432        doesn't make sense to accept an empty string match in pcregrep, so I have
433        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
434        seems to be how GNU grep behaves.
435    
436    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
437        start or after a newline", because the conditional assertion was not being
438        correctly handled. The rule now is that both the assertion and what follows
439        in the first alternative must satisfy the test.
440    
441    9.  If auto-callout was enabled in a pattern with a conditional group whose
442        condition was an assertion, PCRE could crash during matching, both with
443        pcre_exec() and pcre_dfa_exec().
444    
445    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
446        used for matching.
447    
448    11. Unicode property support in character classes was not working for
449        characters (bytes) greater than 127 when not in UTF-8 mode.
450    
451    12. Added the -M command line option to pcretest.
452    
453    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
454    
455    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
456    
457    16. Added comments and documentation about mis-use of no_arg in the C++
458        wrapper.
459    
460    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
461        from Martin Jerabek that uses macro names for all relevant character and
462        string constants.
463    
464    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
465        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
466        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
467        these, but not everybody uses configure.
468    
469    19. A conditional group that had only one branch was not being correctly
470        recognized as an item that could match an empty string. This meant that an
471        enclosing group might also not be so recognized, causing infinite looping
472        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
473        with the subject "ab", where knowledge that the repeated group can match
474        nothing is needed in order to break the loop.
475    
476    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
477        exec(), but without supplying a callout function, matching went wrong.
478    
479    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
480        leak if the size of the offset vector was greater than 30. When the vector
481        is smaller, the saved offsets during recursion go onto a local stack
482        vector, but for larger vectors malloc() is used. It was failing to free
483        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
484        error, in fact).
485    
486    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
487        heapframe that is used only when UTF-8 support is enabled. This caused no
488        problem, but was untidy.
489    
490    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
491        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
492        included within another project.
493    
494    24. Steven Van Ingelgem's patches to add more options to the CMake support,
495        slightly modified by me:
496    
497          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
498              not building pcregrep.
499    
500          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
501              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
502    
503    25. Forward references, both numeric and by name, in patterns that made use of
504        duplicate group numbers, could behave incorrectly or give incorrect errors,
505        because when scanning forward to find the reference group, PCRE was not
506        taking into account the duplicate group numbers. A pattern such as
507        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
508    
509    26. Changed a few more instances of "const unsigned char *" to USPTR, making
510        the feature of a custom pointer more persuasive (as requested by a user).
511    
512    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
513        pcretest.c, inside #ifndefs, because it seems they are sometimes already
514        pre-defined.
515    
516    28. Added support for (*UTF8) at the start of a pattern.
517    
518    29. Arrange for flags added by the "release type" setting in CMake to be shown
519        in the configuration summary.
520    
521    
522    Version 7.8 05-Sep-08
523    ---------------------
524    
525    1.  Replaced UCP searching code with optimized version as implemented for Ad
526        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
527        stage table and inline lookup instead of a function, giving speed ups of 2
528        to 5 times on some simple patterns that I tested. Permission was given to
529        distribute the MultiStage2.py script that generates the tables (it's not in
530        the tarball, but is in the Subversion repository).
531    
532    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
533        scripts.
534    
535    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
536        a group with a zero qualifier. The result of the study could be incorrect,
537        or the function might crash, depending on the pattern.
538    
539    4.  Caseless matching was not working for non-ASCII characters in back
540        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
541        It now works when Unicode Property Support is available.
542    
543    5.  In pcretest, an escape such as \x{de} in the data was always generating
544        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
545        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
546        truncation.
547    
548    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
549    
550    7.  Added two (int) casts to pcregrep when printing the difference of two
551        pointers, in case they are 64-bit values.
552    
553    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
554        test 2 if it fails.
555    
556    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
557        and a #define of that name to empty if it is not externally set. This is to
558        allow users of MSVC to set it if necessary.
559    
560    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
561        the convenience functions in the pcre_get.c source file.
562    
563    11. An option change at the start of a pattern that had top-level alternatives
564        could cause overwriting and/or a crash. This command provoked a crash in
565        some environments:
566    
567          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
568    
569        This potential security problem was recorded as CVE-2008-2371.
570    
571    12. For a pattern where the match had to start at the beginning or immediately
572        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
573        pcre_dfa_exec() could read past the end of the passed subject if there was
574        no match. To help with detecting such bugs (e.g. with valgrind), I modified
575        pcretest so that it places the subject at the end of its malloc-ed buffer.
576    
577    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
578        exec() might read past the end of the data buffer in UTF-8 mode.
579    
580    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
581        the data contained the byte 0x85 as part of a UTF-8 character within its
582        first line. This applied both to normal and DFA matching.
583    
584    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
585        /^[^d]*?$/8 failed to match "abc".
586    
587    16. Added a missing copyright notice to pcrecpp_internal.h.
588    
589    17. Make it more clear in the documentation that values returned from
590        pcre_exec() in ovector are byte offsets, not character counts.
591    
592    18. Tidied a few places to stop certain compilers from issuing warnings.
593    
594    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
595        supplied by Stefan Weber. I made a further small update for 7.8 because
596        there is a change of source arrangements: the pcre_searchfuncs.c module is
597        replaced by pcre_ucd.c.
598    
599    
600    Version 7.7 07-May-08
601    ---------------------
602    
603    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
604        a string to a long long, pretend we don't even have a long long." This is
605        done by checking for the strtoq, strtoll, and _strtoi64 functions.
606    
607    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
608        pre-7.6 versions, which defined a global no_arg variable instead of putting
609        it in the RE class. (See also #8 below.)
610    
611    3.  Remove a line of dead code, identified by coverity and reported by Nuno
612        Lopes.
613    
614    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
615    
616        (1) The include/exclude patterns were being applied to the whole pathnames
617            of files, instead of just to the final components.
618    
619        (2) If there was more than one level of directory, the subdirectories were
620            skipped unless they satisfied the include/exclude conditions. This is
621            inconsistent with GNU grep (and could even be seen as contrary to the
622            pcregrep specification - which I improved to make it absolutely clear).
623            The action now is always to scan all levels of directory, and just
624            apply the include/exclude patterns to regular files.
625    
626    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
627        --exclude_dir in the tests to avoid scanning .svn directories.
628    
629    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
630        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
631        doesn't support NULs in patterns.
632    
633    7.  Added some missing "const"s to declarations of static tables in
634        pcre_compile.c and pcre_dfa_exec.c.
635    
636    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
637        caused by fix #2  above. (Subsequently also a second patch to fix the
638        first patch. And a third patch - this was a messy problem.)
639    
640    9.  Applied Craig's patch to remove the use of push_back().
641    
642    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
643        matching function regexec().
644    
645    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
646        which, however, unlike Perl's \g{...}, are subroutine calls, not back
647        references. PCRE supports relative numbers with this syntax (I don't think
648        Oniguruma does).
649    
650    12. Previously, a group with a zero repeat such as (...){0} was completely
651        omitted from the compiled regex. However, this means that if the group
652        was called as a subroutine from elsewhere in the pattern, things went wrong
653        (an internal error was given). Such groups are now left in the compiled
654        pattern, with a new opcode that causes them to be skipped at execution
655        time.
656    
657    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
658        to the way PCRE behaves:
659    
660        (a) A lone ] character is dis-allowed (Perl treats it as data).
661    
662        (b) A back reference to an unmatched subpattern matches an empty string
663            (Perl fails the current match path).
664    
665        (c) A data ] in a character class must be notated as \] because if the
666            first data character in a class is ], it defines an empty class. (In
667            Perl it is not possible to have an empty class.) The empty class []
668            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
669            The negative empty class [^] matches any one character, independently
670            of the DOTALL setting.
671    
672    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
673        non-existent subpattern following a character class starting with ']' and
674        containing () gave an internal compiling error instead of "reference to
675        non-existent subpattern". Fortunately, when the pattern did exist, the
676        compiled code was correct. (When scanning forwards to check for the
677        existencd of the subpattern, it was treating the data ']' as terminating
678        the class, so got the count wrong. When actually compiling, the reference
679        was subsequently set up correctly.)
680    
681    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
682        it was being rejected as not supported by pcre_dfa_exec(), even though
683        other assertions are supported. I have made pcre_dfa_exec() support
684        (*FAIL).
685    
686    16. The implementation of 13c above involved the invention of a new opcode,
687        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
688        cannot be changed at match time, I realized I could make a small
689        improvement to matching performance by compiling OP_ALLANY instead of
690        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
691        on the OP_ANY path.
692    
693    17. Compiling pcretest on Windows with readline support failed without the
694        following two fixes: (1) Make the unistd.h include conditional on
695        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
696    
697    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
698        ncurses library to be included for pcretest when ReadLine support is
699        requested, but also to allow for it to be overridden. This patch came from
700        Daniel Bergström.
701    
702    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
703        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
704        any errors with the current Unicode tables. Thanks to Peter Kankowski for
705        spotting this.
706    
707    
708    Version 7.6 28-Jan-08
709    ---------------------
710    
711    1.  A character class containing a very large number of characters with
712        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
713        overflow.
714    
715    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
716        HAVE_LONG_LONG is not defined.
717    
718    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
719        bring them up to date and include new features. This patch includes:
720    
721        - Fixed PH's badly added libz and libbz2 support.
722        - Fixed a problem with static linking.
723        - Added pcredemo. [But later removed - see 7 below.]
724        - Fixed dftables problem and added an option.
725        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
726            HAVE_LONG_LONG.
727        - Added readline support for pcretest.
728        - Added an listing of the option settings after cmake has run.
729    
730    4.  A user submitted a patch to Makefile that makes it easy to create
731        "pcre.dll" under mingw when using Configure/Make. I added stuff to
732        Makefile.am that cause it to include this special target, without
733        affecting anything else. Note that the same mingw target plus all
734        the other distribution libraries and programs are now supported
735        when configuring with CMake (see 6 below) instead of with
736        Configure/Make.
737    
738    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
739        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
740        exported in the Windows port". It has not yet been confirmed that the patch
741        solves the problem, but it does no harm.
742    
743    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
744        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
745        with CMake, and also correct the comment about stack recursion.
746    
747    7.  Remove the automatic building of pcredemo from the ./configure system and
748        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
749        of a program that users should build themselves after PCRE is installed, so
750        building it automatically is not really right. What is more, it gave
751        trouble in some build environments.
752    
753    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
754    
755    
756    Version 7.5 10-Jan-08
757    ---------------------
758    
759    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
760        values in parens when parsing an RE using the C++ wrapper."
761    
762    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
763        Characters greater than 255 were excluded from the class instead of being
764        included.
765    
766    3.  The same bug as (2) above applied to negated POSIX classes such as
767        [:^space:].
768    
769    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
770        defined or documented. It seems to have been a typo for PCRE_STATIC, so
771        I have changed it.
772    
773    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
774        first named subpattern) and a construct such as (?&a) would reference the
775        first named subpattern whose name started with "a" (in other words, the
776        length check was missing). Both these problems are fixed. "Subpattern name
777        expected" is now given for (?&) (a zero-length name), and this patch also
778        makes it give the same error for \k'' (previously it complained that that
779        was a reference to a non-existent subpattern).
780    
781    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
782        this is right because (?- can be followed by option settings as well as by
783        digits. I have, however, made the messages clearer.
784    
785    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
786        than the number used in the conditional) now cause a compile-time error.
787        This is actually not compatible with Perl, which accepts such patterns, but
788        treats the conditional as always being FALSE (as PCRE used to), but it
789        seems to me that giving a diagnostic is better.
790    
791    8.  Change "alphameric" to the more common word "alphanumeric" in comments
792        and messages.
793    
794    9.  Fix two occurrences of "backslash" in comments that should have been
795        "backspace".
796    
797    10. Remove two redundant lines of code that can never be obeyed (their function
798        was moved elsewhere).
799    
800    11. The program that makes PCRE's Unicode character property table had a bug
801        which caused it to generate incorrect table entries for sequences of
802        characters that have the same character type, but are in different scripts.
803        It amalgamated them into a single range, with the script of the first of
804        them. In other words, some characters were in the wrong script. There were
805        thirteen such cases, affecting characters in the following ranges:
806    
807          U+002b0 - U+002c1
808          U+0060c - U+0060d
809          U+0061e - U+00612
810          U+0064b - U+0065e
811          U+0074d - U+0076d
812          U+01800 - U+01805
813          U+01d00 - U+01d77
814          U+01d9b - U+01dbf
815          U+0200b - U+0200f
816          U+030fc - U+030fe
817          U+03260 - U+0327f
818          U+0fb46 - U+0fbb1
819          U+10450 - U+1049d
820    
821    12. The -o option (show only the matching part of a line) for pcregrep was not
822        compatible with GNU grep in that, if there was more than one match in a
823        line, it showed only the first of them. It now behaves in the same way as
824        GNU grep.
825    
826    13. If the -o and -v options were combined for pcregrep, it printed a blank
827        line for every non-matching line. GNU grep prints nothing, and pcregrep now
828        does the same. The return code can be used to tell if there were any
829        non-matching lines.
830    
831    14. Added --file-offsets and --line-offsets to pcregrep.
832    
833    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
834        infinitely looping recursion. The bug was that positive lookaheads were not
835        being skipped when checking for a possible empty match (negative lookaheads
836        and both kinds of lookbehind were skipped).
837    
838    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
839        inclusion of <windows.h> to before rather than after the definition of
840        INVALID_FILE_ATTRIBUTES (patch from David Byron).
841    
842    17. Specifying a possessive quantifier with a specific limit for a Unicode
843        character property caused pcre_compile() to compile bad code, which led at
844        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
845        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
846        caused the error; without that there was no problem.
847    
848    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
849    
850    19. Added --enable-pcretest-libreadline.
851    
852    20. In pcrecpp.cc, the variable 'count' was incremented twice in
853        RE::GlobalReplace(). As a result, the number of replacements returned was
854        double what it should be. I removed one of the increments, but Craig sent a
855        later patch that removed the other one (the right fix) and added unit tests
856        that check the return values (which was not done before).
857    
858    21. Several CMake things:
859    
860        (1) Arranged that, when cmake is used on Unix, the libraries end up with
861            the names libpcre and libpcreposix, not just pcre and pcreposix.
862    
863        (2) The above change means that pcretest and pcregrep are now correctly
864            linked with the newly-built libraries, not previously installed ones.
865    
866        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
867    
868    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
869        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
870        UTF-8 newline character). The key issue is that the pattern starts .*;
871        this means that the match must be either at the beginning, or after a
872        newline. The bug was in the code for advancing after a failed match and
873        checking that the new position followed a newline. It was not taking
874        account of UTF-8 characters correctly.
875    
876    23. PCRE was behaving differently from Perl in the way it recognized POSIX
877        character classes. PCRE was not treating the sequence [:...:] as a
878        character class unless the ... were all letters. Perl, however, seems to
879        allow any characters between [: and :], though of course it rejects as
880        unknown any "names" that contain non-letters, because all the known class
881        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
882        for example, whereas PCRE did not - it did not recognize a POSIX character
883        class. This seemed a bit dangerous, so the code has been changed to be
884        closer to Perl. The behaviour is not identical to Perl, because PCRE will
885        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
886        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
887        Perl does, and where it didn't before.
888    
889    24. Rewrite so as to remove the single use of %n from pcregrep because in some
890        Windows environments %n is disabled by default.
891    
892    
893    Version 7.4 21-Sep-07
894    ---------------------
895    
896    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
897        means that a class such as [\s] counted as "explicit reference to CR or
898        LF". That isn't really right - the whole point of the change was to try to
899        help when there was an actual mention of one of the two characters. So now
900        the change happens only if \r or \n (or a literal CR or LF) character is
901        encountered.
902    
903    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
904        of both had grown to the point where there were only 3 bits left.
905        Fortunately, there was spare space in the data structure, and so I have
906        moved the internal flags into a new 16-bit field to free up more option
907        bits.
908    
909    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
910        but did not set the internal JCHANGED flag - either of these is enough to
911        control the way the "get" function works - but the PCRE_INFO_JCHANGED
912        facility is supposed to tell if (?J) was ever used, so now (?J) at the
913        start sets both bits.
914    
915    4.  Added options (at build time, compile time, exec time) to change \R from
916        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
917    
918    5.  doc/pcresyntax.html was missing from the distribution.
919    
920    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
921        compatibility, even though it is no longer used.
922    
923    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
924        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
925        windows.h file is present (where different names are used). [This was
926        reversed later after testing - see 16 below.]
927    
928    8.  Changed all #include <config.h> to #include "config.h". There were also
929        some further <pcre.h> cases that I changed to "pcre.h".
930    
931    9.  When pcregrep was used with the --colour option, it missed the line ending
932        sequence off the lines that it output.
933    
934    10. It was pointed out to me that arrays of string pointers cause lots of
935        relocations when a shared library is dynamically loaded. A technique of
936        using a single long string with a table of offsets can drastically reduce
937        these. I have refactored PCRE in four places to do this. The result is
938        dramatic:
939    
940          Originally:                          290
941          After changing UCP table:            187
942          After changing error message table:   43
943          After changing table of "verbs"       36
944          After changing table of Posix names   22
945    
946        Thanks to the folks working on Gregex for glib for this insight.
947    
948    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
949        unicode-properties was also set.
950    
951    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
952    
953    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
954        checked only for CRLF.
955    
956    14. Added casts to pcretest.c to avoid compiler warnings.
957    
958    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
959    
960    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
961        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
962        entirely. This removes changes made in 7 above.
963    
964    17. The CMake files have been updated, and there is now more information about
965        building with CMake in the NON-UNIX-USE document.
966    
967    
968    Version 7.3 28-Aug-07
969    ---------------------
970    
971     1. In the rejigging of the build system that eventually resulted in 7.1, the
972        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
973        brackets there is not right, since it causes compilers to look for an
974        installed pcre.h, not the version that is in the source that is being
975        compiled (which of course may be different). I have changed it back to:
976    
977          #include "pcre.h"
978    
979        I have a vague recollection that the change was concerned with compiling in
980        different directories, but in the new build system, that is taken care of
981        by the VPATH setting the Makefile.
982    
983     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
984        when the subject happened to end in the byte 0x85 (e.g. if the last
985        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
986        characters but of course it shouldn't be taken as a newline when it is part
987        of another character. The bug was that, for an unlimited repeat of . in
988        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
989        characters when looking for a newline.
990    
991     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
992    
993     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
994        in debug output.
995    
996     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
997        long printing in the pcrecpp unittest when running under MinGW.
998    
999     6. ESC_K was left out of the EBCDIC table.
1000    
1001     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1002        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1003        limit also applies to "virtual nesting" when a pattern is recursive, and in
1004        this case 1000 isn't so big. I have been able to remove this limit at the
1005        expense of backing off one optimization in certain circumstances. Normally,
1006        when pcre_exec() would call its internal match() function recursively and
1007        immediately return the result unconditionally, it uses a "tail recursion"
1008        feature to save stack. However, when a subpattern that can match an empty
1009        string has an unlimited repetition quantifier, it no longer makes this
1010        optimization. That gives it a stack frame in which to save the data for
1011        checking that an empty string has been matched. Previously this was taken
1012        from the 1000-entry workspace that had been reserved. So now there is no
1013        explicit limit, but more stack is used.
1014    
1015     8. Applied Daniel's patches to solve problems with the import/export magic
1016        syntax that is required for Windows, and which was going wrong for the
1017        pcreposix and pcrecpp parts of the library. These were overlooked when this
1018        problem was solved for the main library.
1019    
1020     9. There were some crude static tests to avoid integer overflow when computing
1021        the size of patterns that contain repeated groups with explicit upper
1022        limits. As the maximum quantifier is 65535, the maximum group length was
1023        set at 30,000 so that the product of these two numbers did not overflow a
1024        32-bit integer. However, it turns out that people want to use groups that
1025        are longer than 30,000 bytes (though not repeat them that many times).
1026        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1027        made it possible to implement the integer overflow checks in a much more
1028        dynamic way, which I have now done. The artificial limitation on group
1029        length has been removed - we now have only the limit on the total length of
1030        the compiled pattern, which depends on the LINK_SIZE setting.
1031    
1032    10. Fixed a bug in the documentation for get/copy named substring when
1033        duplicate names are permitted. If none of the named substrings are set, the
1034        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1035        empty string.
1036    
1037    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1038        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1039        because the ] is interpreted as the first data character and the
1040        terminating ] is not found. PCRE has been made compatible with Perl in this
1041        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1042        cause memory overwriting.
1043    
1044    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1045        string has been matched (to stop an infinite loop). It was not recognizing
1046        a conditional subpattern that could match an empty string if that
1047        subpattern was within another subpattern. For example, it looped when
1048        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1049        condition was not nested. This bug has been fixed.
1050    
1051    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1052        past the start of the subject in the presence of bytes with the top bit
1053        set, for example "\x8aBCD".
1054    
1055    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1056        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1057    
1058    14. Optimized (?!) to (*FAIL).
1059    
1060    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1061        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1062        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1063        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1064        does: it's just the validity check that is more restrictive.
1065    
1066    16. Inserted checks for integer overflows during escape sequence (backslash)
1067        processing, and also fixed erroneous offset values for syntax errors during
1068        backslash processing.
1069    
1070    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1071        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1072    
1073    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1074        caused an overrun.
1075    
1076    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1077        something other than just ASCII characters) inside a group that had an
1078        unlimited repeat caused a loop at compile time (while checking to see
1079        whether the group could match an empty string).
1080    
1081    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1082        [\P{Any}] did so. (Error in the code for printing property names.)
1083    
1084    21. An orphan \E inside a character class could cause a crash.
1085    
1086    22. A repeated capturing bracket such as (A)? could cause a wild memory
1087        reference during compilation.
1088    
1089    23. There are several functions in pcre_compile() that scan along a compiled
1090        expression for various reasons (e.g. to see if it's fixed length for look
1091        behind). There were bugs in these functions when a repeated \p or \P was
1092        present in the pattern. These operators have additional parameters compared
1093        with \d, etc, and these were not being taken into account when moving along
1094        the compiled data. Specifically:
1095    
1096        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1097            length.
1098    
1099        (b) An item such as \pL+ within a repeated group could cause crashes or
1100            loops.
1101    
1102        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1103            "reference to non-existent subpattern" error.
1104    
1105        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1106    
1107    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1108        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1109    
1110    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1111    
1112    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1113        character were causing crashes (broken optimization).
1114    
1115    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1116        \p or \P) caused a compile-time loop.
1117    
1118    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1119        break. For example, the unstudied pattern [\r\n]A does not match the string
1120        "\r\nA" because change 7.0/46 below moves the current point on by two
1121        characters after failing to match at the start. However, the pattern \nA
1122        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1123        the same is true. There doesn't seem any very clean way out of this, but
1124        what I have chosen to do makes the common cases work: PCRE now takes note
1125        of whether there can be an explicit match for \r or \n anywhere in the
1126        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1127        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1128        pattern has explicit CR or LF references.
1129    
1130    29. Added (*CR) etc for changing newline setting at start of pattern.
1131    
1132    
1133    Version 7.2 19-Jun-07
1134    ---------------------
1135    
1136     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1137        which is apparently normally available under Windows.
1138    
1139     2. Re-jig the pcregrep tests with different newline settings in an attempt
1140        to make them independent of the local environment's newline setting.
1141    
1142     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1143    
1144     4. Some of the "internals" tests were previously cut out when the link size
1145        was not 2, because the output contained actual offsets. The recent new
1146        "Z" feature of pcretest means that these can be cut out, making the tests
1147        usable with all link sizes.
1148    
1149     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1150        stack recursion. This gives a massive performance boost under BSD, but just
1151        a small improvement under Linux. However, it saves one field in the frame
1152        in all cases.
1153    
1154     6. Added more features from the forthcoming Perl 5.10:
1155    
1156        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1157            recursion call. It refers to the nth most recently opened parentheses.
1158    
1159        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1160            to be opened parentheses.
1161    
1162        (c) Conditions that refer to capturing parentheses can be specified
1163            relatively, for example, (?(-2)... or (?(+3)...
1164    
1165        (d) \K resets the start of the current match so that everything before
1166            is not part of it.
1167    
1168        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1169    
1170        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1171            reference syntax.
1172    
1173        (g) (?| introduces a group in which the numbering of parentheses in each
1174            alternative starts with the same number.
1175    
1176        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1177    
1178     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1179        PCRE_INFO_JCHANGED.
1180    
1181     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1182        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1183        for detecting groups that can match an empty string.
1184    
1185     9. A pattern with a very large number of alternatives (more than several
1186        hundred) was running out of internal workspace during the pre-compile
1187        phase, where pcre_compile() figures out how much memory will be needed. A
1188        bit of new cunning has reduced the workspace needed for groups with
1189        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1190        workspace instead of running out of the 4096 that are available.
1191    
1192    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1193    
1194    11. Applied patch from Google to remove an optimization that didn't quite work.
1195        The report of the bug said:
1196    
1197          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1198          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1199          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1200    
1201    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1202        it matched the wrong number of bytes.
1203    
1204    
1205    Version 7.1 24-Apr-07
1206  ---------------------  ---------------------
1207    
1208   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
1209      that is more "standard", making use of automake and other autotools. There      that is more "standard", making use of automake and other Autotools. There
1210      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
1211      on this.      on this.
1212    
# Line 26  Version 7.1 05-Mar-07 Line 1227  Version 7.1 05-Mar-07
1227      .br or .in.      .br or .in.
1228    
1229   4. Updated comments in configure.ac that get placed in config.h.in and also   4. Updated comments in configure.ac that get placed in config.h.in and also
1230      arranged for config.h to be included in the distribution, with the name      arranged for config.h to be included in the distribution, with the name
1231      config.h.generic, for the benefit of those who have to compile without      config.h.generic, for the benefit of those who have to compile without
1232      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1233    
1234   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1235      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1236      makevp.bat for the current PCRE, using the additional files !compile.txt,      makevp.bat for the current PCRE, using the additional files
1237      !linklib.txt, and pcregexp.pas.      makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1238    
1239   6. A Windows user reported a minor discrepancy with test 2, which turned out   6. A Windows user reported a minor discrepancy with test 2, which turned out
1240      to be caused by a trailing space on an input line that had got lost in his      to be caused by a trailing space on an input line that had got lost in his
# Line 60  Version 7.1 05-Mar-07 Line 1261  Version 7.1 05-Mar-07
1261      called when UTF-8 support is disabled. Otherwise there are problems with a      called when UTF-8 support is disabled. Otherwise there are problems with a
1262      shared library.      shared library.
1263    
1264  10. The emulated memmove() function in pcre_internal.h (provided for those  10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1265      environments that have neither memmove() nor bcopy()) was defining its  
1266      arguments as char * instead of void *.      (a) It was defining its arguments as char * instead of void *.
1267    
1268        (b) It was assuming that all moves were upwards in memory; this was true
1269            a long time ago when I wrote it, but is no longer the case.
1270    
1271        The emulated memove() is provided for those environments that have neither
1272        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1273        is clearly not the case, as these two bugs were recently reported.
1274    
1275  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1276      and Detrail to create the HTML documentation, the .txt form of the man      and Detrail to create the HTML documentation, the .txt form of the man
1277      pages, and it removes trailing spaces from listed files. It also creates      pages, and it removes trailing spaces from listed files. It also creates
1278      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1279      case, it wraps all the #defines with #ifndefs. This script should be run      case, it wraps all the #defines with #ifndefs. This script should be run
1280      before "make dist".      before "make dist".
1281    
1282    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1283        with Unicode property support.
1284    
1285        (a) For a maximizing quantifier, if the two different cases of the
1286            character were of different lengths in their UTF-8 codings (there are
1287            some cases like this - I found 11), and the matching function had to
1288            back up over a mixture of the two cases, it incorrectly assumed they
1289            were both the same length.
1290    
1291        (b) When PCRE was configured to use the heap rather than the stack for
1292            recursion during matching, it was not correctly preserving the data for
1293            the other case of a UTF-8 character when checking ahead for a match
1294            while processing a minimizing repeat. If the check also involved
1295            matching a wide character, but failed, corruption could cause an
1296            erroneous result when trying to check for a repeat of the original
1297            character.
1298    
1299    13. Some tidying changes to the testing mechanism:
1300    
1301        (a) The RunTest script now detects the internal link size and whether there
1302            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1303            values substituted by "configure". (The RunGrepTest script already did
1304            this for UTF-8.) The configure.ac script no longer substitutes the
1305            relevant variables.
1306    
1307        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1308            with length and offset values. This means that the output is different
1309            for different internal link sizes. Test 2 is skipped for link sizes
1310            other than 2 because of this, bypassing the problem. Unfortunately,
1311            there was also a test in test 3 (the locale tests) that used /B and
1312            failed for link sizes other than 2. Rather than cut the whole test out,
1313            I have added a new /Z option to pcretest that replaces the length and
1314            offset values with spaces. This is now used to make test 3 independent
1315            of link size. (Test 2 will be tidied up later.)
1316    
1317    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1318        segmentation fault instead of returning the appropriate error message.
1319    
1320    15. In multiline mode when the newline sequence was set to "any", the pattern
1321        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1322        This doesn't seem right; it now treats the CRLF combination as the line
1323        ending, and so does not match in that case. It's only a pattern such as ^$
1324        that would hit this one: something like ^ABC$ would have failed after \r
1325        and then tried again after \r\n.
1326    
1327    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1328        in an attempt to make files that differ only in their line terminators
1329        compare equal. This works on Linux.
1330    
1331    17. Under certain error circumstances pcregrep might try to free random memory
1332        as it exited. This is now fixed, thanks to valgrind.
1333    
1334    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1335        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1336        was because its rules for how to advance for /g after matching an empty
1337        string at the end of a line did not allow for this case. They now check for
1338        it specially.
1339    
1340    20. pcretest is supposed to handle patterns and data of any length, by
1341        extending its buffers when necessary. It was getting this wrong when the
1342        buffer for a data line had to be extended.
1343    
1344    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1345        CRLF as a newline sequence.
1346    
1347    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1348        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1349        I have nevertheless tidied it up.
1350    
1351    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1352    
1353    24. Added a man page for pcre-config.
1354    
1355    
1356  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1357  ---------------------  ---------------------

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