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revision 122 by ph10, Mon Mar 12 15:10:25 2007 UTC revision 505 by ph10, Tue Mar 9 16:50:47 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 12-Mar-07  Version 8.02 01-Mar-2010
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
8    
9    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
11    
12    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
13        original author of that file, following a query about its status.
14    
15    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
16        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
17    
18    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19        quantifier applied to a forward-referencing subroutine call, could compile
20        incorrect code or give the error "internal error: previously-checked
21        referenced subpattern not found".
22    
23    6.  Both MS Visual Studio and Symbian OS have problems with initializing
24        variables to point to external functions. For these systems, therefore,
25        pcre_malloc etc. are now initialized to local functions that call the
26        relevant global functions.
27    
28    7.  There were two entries missing in the vectors called coptable and poptable
29        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
30        I've fixed the data, and added a kludgy way of testing at compile time that
31        the lengths are correct (equal to the number of opcodes).
32    
33    8.  Following on from 7, I added a similar kludge to check the length of the
34        eint vector in pcreposix.c.
35    
36    9.  Error texts for pcre_compile() are held as one long string to avoid too
37        much relocation at load time. To find a text, the string is searched,
38        counting zeros. There was no check for running off the end of the string,
39        which could happen if a new error number was added without updating the
40        string.
41    
42    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
43    
44    11. \K was not working if it appeared in an atomic group or in a group that
45        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
46        \K is "not well defined" if used in an assertion. PCRE now accepts it if
47        the assertion is positive, but not if it is negative.
48    
49    12. Change 11 fortuitously reduced the size of the stack frame used in the
50        "match()" function of pcre_exec.c by one pointer. Forthcoming
51        implementation of support for (*MARK) will need an extra pointer on the
52        stack; I have reserved it now, so that the stack frame size does not
53        decrease.
54    
55    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
56        item in branch that calls a recursion is a subroutine call - as in the
57        second branch in the above example - was incorrectly given the compile-
58        time error "recursive call could loop indefinitely" because pcre_compile()
59        was not correctly checking the subroutine for matching a non-empty string.
60    
61    14. The checks for overrunning compiling workspace could trigger after an
62        overrun had occurred. This is a "should never occur" error, but it can be
63        triggered by pathological patterns such as hundreds of nested parentheses.
64        The checks now trigger 100 bytes before the end of the workspace.
65    
66    
67    Version 8.01 19-Jan-2010
68    ------------------------
69    
70    1.  If a pattern contained a conditional subpattern with only one branch (in
71        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
72        computed the wrong minimum data length (which is of course zero for such
73        subpatterns). This could cause incorrect "no match" results.
74    
75    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
76        the pattern is reset in the first branch, pcre_compile() failed with
77        "internal error: code overflow at offset...". This happened only when
78        the reset was to the original external option setting. (An optimization
79        abstracts leading options settings into an external setting, which was the
80        cause of this.)
81    
82    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
83        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
84        assertion pattern did not match (meaning that the assertion was true), it
85        was incorrectly treated as false if the SKIP had been reached during the
86        matching. This also applied to assertions used as conditions.
87    
88    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
89        assertion subpattern, including such a pattern used as a condition,
90        unpredictable results occurred, instead of the error return
91        PCRE_ERROR_DFA_UITEM.
92    
93    5.  The C++ GlobalReplace function was not working like Perl for the special
94        situation when an empty string is matched. It now does the fancy magic
95        stuff that is necessary.
96    
97    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
98        removed. (These were left over from very, very early versions of PCRE.)
99    
100    7.  Some cosmetic changes to the code to make life easier when compiling it
101        as part of something else:
102    
103        (a) Change DEBUG to PCRE_DEBUG.
104    
105        (b) In pcre_compile(), rename the member of the "branch_chain" structure
106            called "current" as "current_branch", to prevent a collision with the
107            Linux macro when compiled as a kernel module.
108    
109        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
110            prevent a collision with the Linux macro when compiled as a kernel
111            module.
112    
113    8.  In pcre_compile() there are some checks for integer overflows that used to
114        cast potentially large values to (double). This has been changed to that
115        when building, a check for int64_t is made, and if it is found, it is used
116        instead, thus avoiding the use of floating point arithmetic. (There is no
117        other use of FP in PCRE.) If int64_t is not found, the fallback is to
118        double.
119    
120    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
121        2005 (difference between two addresses compared to an unsigned value).
122    
123    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
124        custom one, because of the following reported problem in Windows:
125    
126          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
127              under Win32.
128          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
129              therefore missing the function definition.
130          - The compiler thus generates a "C" signature for the test function.
131          - The linker fails to find the "C" function.
132          - PCRE fails to configure if asked to do so against libbz2.
133    
134    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
135        messages were output:
136    
137          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
138          rerunning libtoolize, to keep the correct libtool macros in-tree.
139          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
140    
141        I have done both of these things.
142    
143    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
144        most of the time, it *can* run out if it is given a pattern that contains a
145        runaway infinite recursion. I updated the discussion in the pcrestack man
146        page.
147    
148    13. Now that we have gone to the x.xx style of version numbers, the minor
149        version may start with zero. Using 08 or 09 is a bad idea because users
150        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
151        interpreted as invalid octal numbers. I've updated the previous comment in
152        configure.ac, and also added a check that gives an error if 08 or 09 are
153        used.
154    
155    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
156        causing partial matching to fail when the end of the subject matched \W
157        in a UTF-8 pattern where \W was quantified with a minimum of 3.
158    
159    15. There were some discrepancies between the declarations in pcre_internal.h
160        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
161        their definitions. The declarations used "const uschar *" and the
162        definitions used USPTR. Even though USPTR is normally defined as "const
163        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
164        reported that: "This difference in casting confuses some C++ compilers, for
165        example, SunCC recognizes above declarations as different functions and
166        generates broken code for hbpcre." I have changed the declarations to use
167        USPTR.
168    
169    16. GNU libtool is named differently on some systems. The autogen.sh script now
170        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
171        (FreeBSD).
172    
173    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
174        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
175        comment: "Figure out how to create a longlong from a string: strtoll and
176        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
177        instance, but it only takes 2 args instead of 3!"
178    
179    18. A subtle bug concerned with back references has been fixed by a change of
180        specification, with a corresponding code fix. A pattern such as
181        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
182        refers, was giving matches when it shouldn't. For example, xa=xaaa would
183        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
184        same bug. Such groups have to be quantified to be useful, or contained
185        inside another quantified group. (If there's no repetition, the reference
186        can never match.) The problem arises because, having left the group and
187        moved on to the rest of the pattern, a later failure that backtracks into
188        the group uses the captured value from the final iteration of the group
189        rather than the correct earlier one. I have fixed this in PCRE by forcing
190        any group that contains a reference to itself to be an atomic group; that
191        is, there cannot be any backtracking into it once it has completed. This is
192        similar to recursive and subroutine calls.
193    
194    
195    Version 8.00 19-Oct-09
196    ----------------------
197    
198    1.  The table for translating pcre_compile() error codes into POSIX error codes
199        was out-of-date, and there was no check on the pcre_compile() error code
200        being within the table. This could lead to an OK return being given in
201        error.
202    
203    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
204        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
205        in a Windows environment.
206    
207    3.  The pcregrep --count option prints the count for each file even when it is
208        zero, as does GNU grep. However, pcregrep was also printing all files when
209        --files-with-matches was added. Now, when both options are given, it prints
210        counts only for those files that have at least one match. (GNU grep just
211        prints the file name in this circumstance, but including the count seems
212        more useful - otherwise, why use --count?) Also ensured that the
213        combination -clh just lists non-zero counts, with no names.
214    
215    4.  The long form of the pcregrep -F option was incorrectly implemented as
216        --fixed_strings instead of --fixed-strings. This is an incompatible change,
217        but it seems right to fix it, and I didn't think it was worth preserving
218        the old behaviour.
219    
220    5.  The command line items --regex=pattern and --regexp=pattern were not
221        recognized by pcregrep, which required --regex pattern or --regexp pattern
222        (with a space rather than an '='). The man page documented the '=' forms,
223        which are compatible with GNU grep; these now work.
224    
225    6.  No libpcreposix.pc file was created for pkg-config; there was just
226        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
227    
228    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
229        when UCP support is not needed, by modifying the Python script that
230        generates it from Unicode data files. This should not matter if the module
231        is correctly used as a library, but I received one complaint about 50K of
232        unwanted data. My guess is that the person linked everything into his
233        program rather than using a library. Anyway, it does no harm.
234    
235    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
236        was a minimum greater than 1 for a wide character in a possessive
237        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
238        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
239        character. Chaos in the form of incorrect output or a compiling loop could
240        result.
241    
242    9.  The restrictions on what a pattern can contain when partial matching is
243        requested for pcre_exec() have been removed. All patterns can now be
244        partially matched by this function. In addition, if there are at least two
245        slots in the offset vector, the offset of the earliest inspected character
246        for the match and the offset of the end of the subject are set in them when
247        PCRE_ERROR_PARTIAL is returned.
248    
249    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
250        synonymous with PCRE_PARTIAL, for backwards compatibility, and
251        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
252        and may be more useful for multi-segment matching.
253    
254    11. Partial matching with pcre_exec() is now more intuitive. A partial match
255        used to be given if ever the end of the subject was reached; now it is
256        given only if matching could not proceed because another character was
257        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
258        string "Z", which now yields "no match" instead of "partial match". In the
259        case of pcre_dfa_exec(), "no match" is given if every matching path for the
260        final character ended with (*FAIL).
261    
262    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
263        if the pattern had a "must contain" character that was already found in the
264        earlier partial match, unless partial matching was again requested. For
265        example, with the pattern /dog.(body)?/, the "must contain" character is
266        "g". If the first part-match was for the string "dog", restarting with
267        "sbody" failed. This bug has been fixed.
268    
269    13. The string returned by pcre_dfa_exec() after a partial match has been
270        changed so that it starts at the first inspected character rather than the
271        first character of the match. This makes a difference only if the pattern
272        starts with a lookbehind assertion or \b or \B (\K is not supported by
273        pcre_dfa_exec()). It's an incompatible change, but it makes the two
274        matching functions compatible, and I think it's the right thing to do.
275    
276    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
277        so that the demonstration program is easily available in environments where
278        PCRE has not been installed from source.
279    
280    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
281        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
282        library.
283    
284    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
285        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
286        is not the first non-POSIX option to be added. Clearly some people find
287        these options useful.
288    
289    17. If a caller to the POSIX matching function regexec() passes a non-zero
290        value for nmatch with a NULL value for pmatch, the value of
291        nmatch is forced to zero.
292    
293    18. RunGrepTest did not have a test for the availability of the -u option of
294        the diff command, as RunTest does. It now checks in the same way as
295        RunTest, and also checks for the -b option.
296    
297    19. If an odd number of negated classes containing just a single character
298        interposed, within parentheses, between a forward reference to a named
299        subpattern and the definition of the subpattern, compilation crashed with
300        an internal error, complaining that it could not find the referenced
301        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
302        [The bug was that it was starting one character too far in when skipping
303        over the character class, thus treating the ] as data rather than
304        terminating the class. This meant it could skip too much.]
305    
306    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
307        /g option in pcretest when the pattern contains \K, which makes it possible
308        to have an empty string match not at the start, even when the pattern is
309        anchored. Updated pcretest and pcredemo to use this option.
310    
311    21. If the maximum number of capturing subpatterns in a recursion was greater
312        than the maximum at the outer level, the higher number was returned, but
313        with unset values at the outer level. The correct (outer level) value is
314        now given.
315    
316    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
317        PCRE did not set those parentheses (unlike Perl). I have now found a way to
318        make it do so. The string so far is captured, making this feature
319        compatible with Perl.
320    
321    23. The tests have been re-organized, adding tests 11 and 12, to make it
322        possible to check the Perl 5.10 features against Perl 5.10.
323    
324    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
325        pattern matches a fixed length string. PCRE did not allow this; now it
326        does. Neither allows recursion.
327    
328    25. I finally figured out how to implement a request to provide the minimum
329        length of subject string that was needed in order to match a given pattern.
330        (It was back references and recursion that I had previously got hung up
331        on.) This code has now been added to pcre_study(); it finds a lower bound
332        to the length of subject needed. It is not necessarily the greatest lower
333        bound, but using it to avoid searching strings that are too short does give
334        some useful speed-ups. The value is available to calling programs via
335        pcre_fullinfo().
336    
337    26. While implementing 25, I discovered to my embarrassment that pcretest had
338        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
339        study optimizations had never been tested with that matching function.
340        Oops. What is worse, even when it was passed study data, there was a bug in
341        pcre_dfa_exec() that meant it never actually used it. Double oops. There
342        were also very few tests of studied patterns with pcre_dfa_exec().
343    
344    27. If (?| is used to create subpatterns with duplicate numbers, they are now
345        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
346        on the other side of the coin, they are no longer allowed to have different
347        names, because these cannot be distinguished in PCRE, and this has caused
348        confusion. (This is a difference from Perl.)
349    
350    28. When duplicate subpattern names are present (necessarily with different
351        numbers, as required by 27 above), and a test is made by name in a
352        conditional pattern, either for a subpattern having been matched, or for
353        recursion in such a pattern, all the associated numbered subpatterns are
354        tested, and the overall condition is true if the condition is true for any
355        one of them. This is the way Perl works, and is also more like the way
356        testing by number works.
357    
358    
359    Version 7.9 11-Apr-09
360    ---------------------
361    
362    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
363        (pcretest), all targets were linked against these libraries. This included
364        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
365        libraries. This caused unwanted dependencies to be created. This problem
366        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
367        pcretest is linked with readline.
368    
369    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
370        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
371        moved outside it again, because FALSE and TRUE are already defined in AIX,
372        but BOOL is not.
373    
374    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
375        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
376    
377    4.  The pcregrep documentation said spaces were inserted as well as colons (or
378        hyphens) following file names and line numbers when outputting matching
379        lines. This is not true; no spaces are inserted. I have also clarified the
380        wording for the --colour (or --color) option.
381    
382    5.  In pcregrep, when --colour was used with -o, the list of matching strings
383        was not coloured; this is different to GNU grep, so I have changed it to be
384        the same.
385    
386    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
387        each matching line was coloured. Now it goes on to look for further matches
388        of any of the test patterns, which is the same behaviour as GNU grep.
389    
390    7.  A pattern that could match an empty string could cause pcregrep to loop; it
391        doesn't make sense to accept an empty string match in pcregrep, so I have
392        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
393        seems to be how GNU grep behaves.
394    
395    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
396        start or after a newline", because the conditional assertion was not being
397        correctly handled. The rule now is that both the assertion and what follows
398        in the first alternative must satisfy the test.
399    
400    9.  If auto-callout was enabled in a pattern with a conditional group whose
401        condition was an assertion, PCRE could crash during matching, both with
402        pcre_exec() and pcre_dfa_exec().
403    
404    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
405        used for matching.
406    
407    11. Unicode property support in character classes was not working for
408        characters (bytes) greater than 127 when not in UTF-8 mode.
409    
410    12. Added the -M command line option to pcretest.
411    
412    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
413    
414    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
415    
416    16. Added comments and documentation about mis-use of no_arg in the C++
417        wrapper.
418    
419    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
420        from Martin Jerabek that uses macro names for all relevant character and
421        string constants.
422    
423    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
424        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
425        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
426        these, but not everybody uses configure.
427    
428    19. A conditional group that had only one branch was not being correctly
429        recognized as an item that could match an empty string. This meant that an
430        enclosing group might also not be so recognized, causing infinite looping
431        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
432        with the subject "ab", where knowledge that the repeated group can match
433        nothing is needed in order to break the loop.
434    
435    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
436        exec(), but without supplying a callout function, matching went wrong.
437    
438    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
439        leak if the size of the offset vector was greater than 30. When the vector
440        is smaller, the saved offsets during recursion go onto a local stack
441        vector, but for larger vectors malloc() is used. It was failing to free
442        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
443        error, in fact).
444    
445    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
446        heapframe that is used only when UTF-8 support is enabled. This caused no
447        problem, but was untidy.
448    
449    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
450        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
451        included within another project.
452    
453    24. Steven Van Ingelgem's patches to add more options to the CMake support,
454        slightly modified by me:
455    
456          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
457              not building pcregrep.
458    
459          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
460              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
461    
462    25. Forward references, both numeric and by name, in patterns that made use of
463        duplicate group numbers, could behave incorrectly or give incorrect errors,
464        because when scanning forward to find the reference group, PCRE was not
465        taking into account the duplicate group numbers. A pattern such as
466        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
467    
468    26. Changed a few more instances of "const unsigned char *" to USPTR, making
469        the feature of a custom pointer more persuasive (as requested by a user).
470    
471    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
472        pcretest.c, inside #ifndefs, because it seems they are sometimes already
473        pre-defined.
474    
475    28. Added support for (*UTF8) at the start of a pattern.
476    
477    29. Arrange for flags added by the "release type" setting in CMake to be shown
478        in the configuration summary.
479    
480    
481    Version 7.8 05-Sep-08
482    ---------------------
483    
484    1.  Replaced UCP searching code with optimized version as implemented for Ad
485        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
486        stage table and inline lookup instead of a function, giving speed ups of 2
487        to 5 times on some simple patterns that I tested. Permission was given to
488        distribute the MultiStage2.py script that generates the tables (it's not in
489        the tarball, but is in the Subversion repository).
490    
491    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
492        scripts.
493    
494    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
495        a group with a zero qualifier. The result of the study could be incorrect,
496        or the function might crash, depending on the pattern.
497    
498    4.  Caseless matching was not working for non-ASCII characters in back
499        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
500        It now works when Unicode Property Support is available.
501    
502    5.  In pcretest, an escape such as \x{de} in the data was always generating
503        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
504        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
505        truncation.
506    
507    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
508    
509    7.  Added two (int) casts to pcregrep when printing the difference of two
510        pointers, in case they are 64-bit values.
511    
512    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
513        test 2 if it fails.
514    
515    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
516        and a #define of that name to empty if it is not externally set. This is to
517        allow users of MSVC to set it if necessary.
518    
519    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
520        the convenience functions in the pcre_get.c source file.
521    
522    11. An option change at the start of a pattern that had top-level alternatives
523        could cause overwriting and/or a crash. This command provoked a crash in
524        some environments:
525    
526          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
527    
528        This potential security problem was recorded as CVE-2008-2371.
529    
530    12. For a pattern where the match had to start at the beginning or immediately
531        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
532        pcre_dfa_exec() could read past the end of the passed subject if there was
533        no match. To help with detecting such bugs (e.g. with valgrind), I modified
534        pcretest so that it places the subject at the end of its malloc-ed buffer.
535    
536    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
537        exec() might read past the end of the data buffer in UTF-8 mode.
538    
539    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
540        the data contained the byte 0x85 as part of a UTF-8 character within its
541        first line. This applied both to normal and DFA matching.
542    
543    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
544        /^[^d]*?$/8 failed to match "abc".
545    
546    16. Added a missing copyright notice to pcrecpp_internal.h.
547    
548    17. Make it more clear in the documentation that values returned from
549        pcre_exec() in ovector are byte offsets, not character counts.
550    
551    18. Tidied a few places to stop certain compilers from issuing warnings.
552    
553    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
554        supplied by Stefan Weber. I made a further small update for 7.8 because
555        there is a change of source arrangements: the pcre_searchfuncs.c module is
556        replaced by pcre_ucd.c.
557    
558    
559    Version 7.7 07-May-08
560    ---------------------
561    
562    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
563        a string to a long long, pretend we don't even have a long long." This is
564        done by checking for the strtoq, strtoll, and _strtoi64 functions.
565    
566    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
567        pre-7.6 versions, which defined a global no_arg variable instead of putting
568        it in the RE class. (See also #8 below.)
569    
570    3.  Remove a line of dead code, identified by coverity and reported by Nuno
571        Lopes.
572    
573    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
574    
575        (1) The include/exclude patterns were being applied to the whole pathnames
576            of files, instead of just to the final components.
577    
578        (2) If there was more than one level of directory, the subdirectories were
579            skipped unless they satisfied the include/exclude conditions. This is
580            inconsistent with GNU grep (and could even be seen as contrary to the
581            pcregrep specification - which I improved to make it absolutely clear).
582            The action now is always to scan all levels of directory, and just
583            apply the include/exclude patterns to regular files.
584    
585    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
586        --exclude_dir in the tests to avoid scanning .svn directories.
587    
588    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
589        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
590        doesn't support NULs in patterns.
591    
592    7.  Added some missing "const"s to declarations of static tables in
593        pcre_compile.c and pcre_dfa_exec.c.
594    
595    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
596        caused by fix #2  above. (Subsequently also a second patch to fix the
597        first patch. And a third patch - this was a messy problem.)
598    
599    9.  Applied Craig's patch to remove the use of push_back().
600    
601    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
602        matching function regexec().
603    
604    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
605        which, however, unlike Perl's \g{...}, are subroutine calls, not back
606        references. PCRE supports relative numbers with this syntax (I don't think
607        Oniguruma does).
608    
609    12. Previously, a group with a zero repeat such as (...){0} was completely
610        omitted from the compiled regex. However, this means that if the group
611        was called as a subroutine from elsewhere in the pattern, things went wrong
612        (an internal error was given). Such groups are now left in the compiled
613        pattern, with a new opcode that causes them to be skipped at execution
614        time.
615    
616    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
617        to the way PCRE behaves:
618    
619        (a) A lone ] character is dis-allowed (Perl treats it as data).
620    
621        (b) A back reference to an unmatched subpattern matches an empty string
622            (Perl fails the current match path).
623    
624        (c) A data ] in a character class must be notated as \] because if the
625            first data character in a class is ], it defines an empty class. (In
626            Perl it is not possible to have an empty class.) The empty class []
627            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
628            The negative empty class [^] matches any one character, independently
629            of the DOTALL setting.
630    
631    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
632        non-existent subpattern following a character class starting with ']' and
633        containing () gave an internal compiling error instead of "reference to
634        non-existent subpattern". Fortunately, when the pattern did exist, the
635        compiled code was correct. (When scanning forwards to check for the
636        existencd of the subpattern, it was treating the data ']' as terminating
637        the class, so got the count wrong. When actually compiling, the reference
638        was subsequently set up correctly.)
639    
640    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
641        it was being rejected as not supported by pcre_dfa_exec(), even though
642        other assertions are supported. I have made pcre_dfa_exec() support
643        (*FAIL).
644    
645    16. The implementation of 13c above involved the invention of a new opcode,
646        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
647        cannot be changed at match time, I realized I could make a small
648        improvement to matching performance by compiling OP_ALLANY instead of
649        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
650        on the OP_ANY path.
651    
652    17. Compiling pcretest on Windows with readline support failed without the
653        following two fixes: (1) Make the unistd.h include conditional on
654        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
655    
656    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
657        ncurses library to be included for pcretest when ReadLine support is
658        requested, but also to allow for it to be overridden. This patch came from
659        Daniel Bergström.
660    
661    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
662        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
663        any errors with the current Unicode tables. Thanks to Peter Kankowski for
664        spotting this.
665    
666    
667    Version 7.6 28-Jan-08
668    ---------------------
669    
670    1.  A character class containing a very large number of characters with
671        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
672        overflow.
673    
674    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
675        HAVE_LONG_LONG is not defined.
676    
677    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
678        bring them up to date and include new features. This patch includes:
679    
680        - Fixed PH's badly added libz and libbz2 support.
681        - Fixed a problem with static linking.
682        - Added pcredemo. [But later removed - see 7 below.]
683        - Fixed dftables problem and added an option.
684        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
685            HAVE_LONG_LONG.
686        - Added readline support for pcretest.
687        - Added an listing of the option settings after cmake has run.
688    
689    4.  A user submitted a patch to Makefile that makes it easy to create
690        "pcre.dll" under mingw when using Configure/Make. I added stuff to
691        Makefile.am that cause it to include this special target, without
692        affecting anything else. Note that the same mingw target plus all
693        the other distribution libraries and programs are now supported
694        when configuring with CMake (see 6 below) instead of with
695        Configure/Make.
696    
697    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
698        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
699        exported in the Windows port". It has not yet been confirmed that the patch
700        solves the problem, but it does no harm.
701    
702    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
703        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
704        with CMake, and also correct the comment about stack recursion.
705    
706    7.  Remove the automatic building of pcredemo from the ./configure system and
707        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
708        of a program that users should build themselves after PCRE is installed, so
709        building it automatically is not really right. What is more, it gave
710        trouble in some build environments.
711    
712    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
713    
714    
715    Version 7.5 10-Jan-08
716    ---------------------
717    
718    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
719        values in parens when parsing an RE using the C++ wrapper."
720    
721    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
722        Characters greater than 255 were excluded from the class instead of being
723        included.
724    
725    3.  The same bug as (2) above applied to negated POSIX classes such as
726        [:^space:].
727    
728    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
729        defined or documented. It seems to have been a typo for PCRE_STATIC, so
730        I have changed it.
731    
732    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
733        first named subpattern) and a construct such as (?&a) would reference the
734        first named subpattern whose name started with "a" (in other words, the
735        length check was missing). Both these problems are fixed. "Subpattern name
736        expected" is now given for (?&) (a zero-length name), and this patch also
737        makes it give the same error for \k'' (previously it complained that that
738        was a reference to a non-existent subpattern).
739    
740    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
741        this is right because (?- can be followed by option settings as well as by
742        digits. I have, however, made the messages clearer.
743    
744    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
745        than the number used in the conditional) now cause a compile-time error.
746        This is actually not compatible with Perl, which accepts such patterns, but
747        treats the conditional as always being FALSE (as PCRE used to), but it
748        seems to me that giving a diagnostic is better.
749    
750    8.  Change "alphameric" to the more common word "alphanumeric" in comments
751        and messages.
752    
753    9.  Fix two occurrences of "backslash" in comments that should have been
754        "backspace".
755    
756    10. Remove two redundant lines of code that can never be obeyed (their function
757        was moved elsewhere).
758    
759    11. The program that makes PCRE's Unicode character property table had a bug
760        which caused it to generate incorrect table entries for sequences of
761        characters that have the same character type, but are in different scripts.
762        It amalgamated them into a single range, with the script of the first of
763        them. In other words, some characters were in the wrong script. There were
764        thirteen such cases, affecting characters in the following ranges:
765    
766          U+002b0 - U+002c1
767          U+0060c - U+0060d
768          U+0061e - U+00612
769          U+0064b - U+0065e
770          U+0074d - U+0076d
771          U+01800 - U+01805
772          U+01d00 - U+01d77
773          U+01d9b - U+01dbf
774          U+0200b - U+0200f
775          U+030fc - U+030fe
776          U+03260 - U+0327f
777          U+0fb46 - U+0fbb1
778          U+10450 - U+1049d
779    
780    12. The -o option (show only the matching part of a line) for pcregrep was not
781        compatible with GNU grep in that, if there was more than one match in a
782        line, it showed only the first of them. It now behaves in the same way as
783        GNU grep.
784    
785    13. If the -o and -v options were combined for pcregrep, it printed a blank
786        line for every non-matching line. GNU grep prints nothing, and pcregrep now
787        does the same. The return code can be used to tell if there were any
788        non-matching lines.
789    
790    14. Added --file-offsets and --line-offsets to pcregrep.
791    
792    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
793        infinitely looping recursion. The bug was that positive lookaheads were not
794        being skipped when checking for a possible empty match (negative lookaheads
795        and both kinds of lookbehind were skipped).
796    
797    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
798        inclusion of <windows.h> to before rather than after the definition of
799        INVALID_FILE_ATTRIBUTES (patch from David Byron).
800    
801    17. Specifying a possessive quantifier with a specific limit for a Unicode
802        character property caused pcre_compile() to compile bad code, which led at
803        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
804        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
805        caused the error; without that there was no problem.
806    
807    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
808    
809    19. Added --enable-pcretest-libreadline.
810    
811    20. In pcrecpp.cc, the variable 'count' was incremented twice in
812        RE::GlobalReplace(). As a result, the number of replacements returned was
813        double what it should be. I removed one of the increments, but Craig sent a
814        later patch that removed the other one (the right fix) and added unit tests
815        that check the return values (which was not done before).
816    
817    21. Several CMake things:
818    
819        (1) Arranged that, when cmake is used on Unix, the libraries end up with
820            the names libpcre and libpcreposix, not just pcre and pcreposix.
821    
822        (2) The above change means that pcretest and pcregrep are now correctly
823            linked with the newly-built libraries, not previously installed ones.
824    
825        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
826    
827    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
828        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
829        UTF-8 newline character). The key issue is that the pattern starts .*;
830        this means that the match must be either at the beginning, or after a
831        newline. The bug was in the code for advancing after a failed match and
832        checking that the new position followed a newline. It was not taking
833        account of UTF-8 characters correctly.
834    
835    23. PCRE was behaving differently from Perl in the way it recognized POSIX
836        character classes. PCRE was not treating the sequence [:...:] as a
837        character class unless the ... were all letters. Perl, however, seems to
838        allow any characters between [: and :], though of course it rejects as
839        unknown any "names" that contain non-letters, because all the known class
840        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
841        for example, whereas PCRE did not - it did not recognize a POSIX character
842        class. This seemed a bit dangerous, so the code has been changed to be
843        closer to Perl. The behaviour is not identical to Perl, because PCRE will
844        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
845        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
846        Perl does, and where it didn't before.
847    
848    24. Rewrite so as to remove the single use of %n from pcregrep because in some
849        Windows environments %n is disabled by default.
850    
851    
852    Version 7.4 21-Sep-07
853    ---------------------
854    
855    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
856        means that a class such as [\s] counted as "explicit reference to CR or
857        LF". That isn't really right - the whole point of the change was to try to
858        help when there was an actual mention of one of the two characters. So now
859        the change happens only if \r or \n (or a literal CR or LF) character is
860        encountered.
861    
862    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
863        of both had grown to the point where there were only 3 bits left.
864        Fortunately, there was spare space in the data structure, and so I have
865        moved the internal flags into a new 16-bit field to free up more option
866        bits.
867    
868    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
869        but did not set the internal JCHANGED flag - either of these is enough to
870        control the way the "get" function works - but the PCRE_INFO_JCHANGED
871        facility is supposed to tell if (?J) was ever used, so now (?J) at the
872        start sets both bits.
873    
874    4.  Added options (at build time, compile time, exec time) to change \R from
875        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
876    
877    5.  doc/pcresyntax.html was missing from the distribution.
878    
879    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
880        compatibility, even though it is no longer used.
881    
882    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
883        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
884        windows.h file is present (where different names are used). [This was
885        reversed later after testing - see 16 below.]
886    
887    8.  Changed all #include <config.h> to #include "config.h". There were also
888        some further <pcre.h> cases that I changed to "pcre.h".
889    
890    9.  When pcregrep was used with the --colour option, it missed the line ending
891        sequence off the lines that it output.
892    
893    10. It was pointed out to me that arrays of string pointers cause lots of
894        relocations when a shared library is dynamically loaded. A technique of
895        using a single long string with a table of offsets can drastically reduce
896        these. I have refactored PCRE in four places to do this. The result is
897        dramatic:
898    
899          Originally:                          290
900          After changing UCP table:            187
901          After changing error message table:   43
902          After changing table of "verbs"       36
903          After changing table of Posix names   22
904    
905        Thanks to the folks working on Gregex for glib for this insight.
906    
907    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
908        unicode-properties was also set.
909    
910    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
911    
912    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
913        checked only for CRLF.
914    
915    14. Added casts to pcretest.c to avoid compiler warnings.
916    
917    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
918    
919    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
920        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
921        entirely. This removes changes made in 7 above.
922    
923    17. The CMake files have been updated, and there is now more information about
924        building with CMake in the NON-UNIX-USE document.
925    
926    
927    Version 7.3 28-Aug-07
928    ---------------------
929    
930     1. In the rejigging of the build system that eventually resulted in 7.1, the
931        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
932        brackets there is not right, since it causes compilers to look for an
933        installed pcre.h, not the version that is in the source that is being
934        compiled (which of course may be different). I have changed it back to:
935    
936          #include "pcre.h"
937    
938        I have a vague recollection that the change was concerned with compiling in
939        different directories, but in the new build system, that is taken care of
940        by the VPATH setting the Makefile.
941    
942     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
943        when the subject happened to end in the byte 0x85 (e.g. if the last
944        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
945        characters but of course it shouldn't be taken as a newline when it is part
946        of another character. The bug was that, for an unlimited repeat of . in
947        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
948        characters when looking for a newline.
949    
950     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
951    
952     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
953        in debug output.
954    
955     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
956        long printing in the pcrecpp unittest when running under MinGW.
957    
958     6. ESC_K was left out of the EBCDIC table.
959    
960     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
961        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
962        limit also applies to "virtual nesting" when a pattern is recursive, and in
963        this case 1000 isn't so big. I have been able to remove this limit at the
964        expense of backing off one optimization in certain circumstances. Normally,
965        when pcre_exec() would call its internal match() function recursively and
966        immediately return the result unconditionally, it uses a "tail recursion"
967        feature to save stack. However, when a subpattern that can match an empty
968        string has an unlimited repetition quantifier, it no longer makes this
969        optimization. That gives it a stack frame in which to save the data for
970        checking that an empty string has been matched. Previously this was taken
971        from the 1000-entry workspace that had been reserved. So now there is no
972        explicit limit, but more stack is used.
973    
974     8. Applied Daniel's patches to solve problems with the import/export magic
975        syntax that is required for Windows, and which was going wrong for the
976        pcreposix and pcrecpp parts of the library. These were overlooked when this
977        problem was solved for the main library.
978    
979     9. There were some crude static tests to avoid integer overflow when computing
980        the size of patterns that contain repeated groups with explicit upper
981        limits. As the maximum quantifier is 65535, the maximum group length was
982        set at 30,000 so that the product of these two numbers did not overflow a
983        32-bit integer. However, it turns out that people want to use groups that
984        are longer than 30,000 bytes (though not repeat them that many times).
985        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
986        made it possible to implement the integer overflow checks in a much more
987        dynamic way, which I have now done. The artificial limitation on group
988        length has been removed - we now have only the limit on the total length of
989        the compiled pattern, which depends on the LINK_SIZE setting.
990    
991    10. Fixed a bug in the documentation for get/copy named substring when
992        duplicate names are permitted. If none of the named substrings are set, the
993        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
994        empty string.
995    
996    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
997        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
998        because the ] is interpreted as the first data character and the
999        terminating ] is not found. PCRE has been made compatible with Perl in this
1000        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1001        cause memory overwriting.
1002    
1003    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1004        string has been matched (to stop an infinite loop). It was not recognizing
1005        a conditional subpattern that could match an empty string if that
1006        subpattern was within another subpattern. For example, it looped when
1007        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1008        condition was not nested. This bug has been fixed.
1009    
1010    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1011        past the start of the subject in the presence of bytes with the top bit
1012        set, for example "\x8aBCD".
1013    
1014    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1015        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1016    
1017    14. Optimized (?!) to (*FAIL).
1018    
1019    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1020        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1021        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1022        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1023        does: it's just the validity check that is more restrictive.
1024    
1025    16. Inserted checks for integer overflows during escape sequence (backslash)
1026        processing, and also fixed erroneous offset values for syntax errors during
1027        backslash processing.
1028    
1029    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1030        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1031    
1032    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1033        caused an overrun.
1034    
1035    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1036        something other than just ASCII characters) inside a group that had an
1037        unlimited repeat caused a loop at compile time (while checking to see
1038        whether the group could match an empty string).
1039    
1040    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1041        [\P{Any}] did so. (Error in the code for printing property names.)
1042    
1043    21. An orphan \E inside a character class could cause a crash.
1044    
1045    22. A repeated capturing bracket such as (A)? could cause a wild memory
1046        reference during compilation.
1047    
1048    23. There are several functions in pcre_compile() that scan along a compiled
1049        expression for various reasons (e.g. to see if it's fixed length for look
1050        behind). There were bugs in these functions when a repeated \p or \P was
1051        present in the pattern. These operators have additional parameters compared
1052        with \d, etc, and these were not being taken into account when moving along
1053        the compiled data. Specifically:
1054    
1055        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1056            length.
1057    
1058        (b) An item such as \pL+ within a repeated group could cause crashes or
1059            loops.
1060    
1061        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1062            "reference to non-existent subpattern" error.
1063    
1064        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1065    
1066    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1067        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1068    
1069    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1070    
1071    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1072        character were causing crashes (broken optimization).
1073    
1074    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1075        \p or \P) caused a compile-time loop.
1076    
1077    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1078        break. For example, the unstudied pattern [\r\n]A does not match the string
1079        "\r\nA" because change 7.0/46 below moves the current point on by two
1080        characters after failing to match at the start. However, the pattern \nA
1081        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1082        the same is true. There doesn't seem any very clean way out of this, but
1083        what I have chosen to do makes the common cases work: PCRE now takes note
1084        of whether there can be an explicit match for \r or \n anywhere in the
1085        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1086        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1087        pattern has explicit CR or LF references.
1088    
1089    29. Added (*CR) etc for changing newline setting at start of pattern.
1090    
1091    
1092    Version 7.2 19-Jun-07
1093    ---------------------
1094    
1095     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1096        which is apparently normally available under Windows.
1097    
1098     2. Re-jig the pcregrep tests with different newline settings in an attempt
1099        to make them independent of the local environment's newline setting.
1100    
1101     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1102    
1103     4. Some of the "internals" tests were previously cut out when the link size
1104        was not 2, because the output contained actual offsets. The recent new
1105        "Z" feature of pcretest means that these can be cut out, making the tests
1106        usable with all link sizes.
1107    
1108     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1109        stack recursion. This gives a massive performance boost under BSD, but just
1110        a small improvement under Linux. However, it saves one field in the frame
1111        in all cases.
1112    
1113     6. Added more features from the forthcoming Perl 5.10:
1114    
1115        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1116            recursion call. It refers to the nth most recently opened parentheses.
1117    
1118        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1119            to be opened parentheses.
1120    
1121        (c) Conditions that refer to capturing parentheses can be specified
1122            relatively, for example, (?(-2)... or (?(+3)...
1123    
1124        (d) \K resets the start of the current match so that everything before
1125            is not part of it.
1126    
1127        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1128    
1129        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1130            reference syntax.
1131    
1132        (g) (?| introduces a group in which the numbering of parentheses in each
1133            alternative starts with the same number.
1134    
1135        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1136    
1137     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1138        PCRE_INFO_JCHANGED.
1139    
1140     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1141        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1142        for detecting groups that can match an empty string.
1143    
1144     9. A pattern with a very large number of alternatives (more than several
1145        hundred) was running out of internal workspace during the pre-compile
1146        phase, where pcre_compile() figures out how much memory will be needed. A
1147        bit of new cunning has reduced the workspace needed for groups with
1148        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1149        workspace instead of running out of the 4096 that are available.
1150    
1151    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1152    
1153    11. Applied patch from Google to remove an optimization that didn't quite work.
1154        The report of the bug said:
1155    
1156          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1157          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1158          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1159    
1160    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1161        it matched the wrong number of bytes.
1162    
1163    
1164    Version 7.1 24-Apr-07
1165  ---------------------  ---------------------
1166    
1167   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
# Line 26  Version 7.1 12-Mar-07 Line 1186  Version 7.1 12-Mar-07
1186      .br or .in.      .br or .in.
1187    
1188   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
1189      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
1190      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
1191      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1192    
1193   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
1194      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1195      makevp.bat for the current PCRE, using the additional files !compile.txt,      makevp.bat for the current PCRE, using the additional files
1196      !linklib.txt, and pcregexp.pas.      makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1197    
1198   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
1199      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 63  Version 7.1 12-Mar-07 Line 1223  Version 7.1 12-Mar-07
1223  10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:  10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1224    
1225      (a) It was defining its arguments as char * instead of void *.      (a) It was defining its arguments as char * instead of void *.
1226    
1227      (b) It was assuming that all moves were upwards in memory; this was true      (b) It was assuming that all moves were upwards in memory; this was true
1228          a long time ago when I wrote it, but is no longer the case.          a long time ago when I wrote it, but is no longer the case.
1229    
1230      The emulated memove() is provided for those environments that have neither      The emulated memove() is provided for those environments that have neither
1231      memmove() nor bcopy(). I didn't think anyone used it these days, but that      memmove() nor bcopy(). I didn't think anyone used it these days, but that
1232      is clearly not the case, as these two bugs were recently reported.      is clearly not the case, as these two bugs were recently reported.
1233    
1234  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1235      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
1236      pages, and it removes trailing spaces from listed files. It also creates      pages, and it removes trailing spaces from listed files. It also creates
1237      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
1238      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
1239      before "make dist".      before "make dist".
1240    
1241  12. Fixed two fairly obscure bugs concerned with quantified caseless matching  12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1242      with Unicode property support.      with Unicode property support.
1243    
1244      (a) For a maximizing quantifier, if the two different cases of the      (a) For a maximizing quantifier, if the two different cases of the
1245          character were of different lengths in their UTF-8 codings (there are          character were of different lengths in their UTF-8 codings (there are
1246          some cases like this - I found 11), and the matching function had to          some cases like this - I found 11), and the matching function had to
1247          back up over a mixture of the two cases, it incorrectly assumed they          back up over a mixture of the two cases, it incorrectly assumed they
1248          were both the same length.          were both the same length.
1249    
1250      (b) When PCRE was configured to use the heap rather than the stack for      (b) When PCRE was configured to use the heap rather than the stack for
1251          recursion during matching, it was not correctly preserving the data for          recursion during matching, it was not correctly preserving the data for
1252          the other case of a UTF-8 character when checking ahead for a match          the other case of a UTF-8 character when checking ahead for a match
1253          while processing a minimizing repeat. If the check also involved          while processing a minimizing repeat. If the check also involved
1254          matching a wide character, but failed, corruption could cause an          matching a wide character, but failed, corruption could cause an
1255          erroneous result when trying to check for a repeat of the original          erroneous result when trying to check for a repeat of the original
1256          character.          character.
1257    
1258  13. Some tidying changes to the testing mechanism:  13. Some tidying changes to the testing mechanism:
1259    
1260      (a) The RunTest script now detects the internal link size and whether there      (a) The RunTest script now detects the internal link size and whether there
1261          is UTF-8 and UCP support by running ./pcretest -C instead of relying on          is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1262          values substituted by "configure". (The RunGrepTest script already did          values substituted by "configure". (The RunGrepTest script already did
1263          this for UTF-8.) The configure.ac script no longer substitutes the          this for UTF-8.) The configure.ac script no longer substitutes the
1264          relevant variables.          relevant variables.
1265    
1266      (b) The debugging options /B and /D in pcretest show the compiled bytecode      (b) The debugging options /B and /D in pcretest show the compiled bytecode
1267          with length and offset values. This means that the output is different          with length and offset values. This means that the output is different
1268          for different internal link sizes. Test 2 is skipped for link sizes          for different internal link sizes. Test 2 is skipped for link sizes
1269          other than 2 because of this, bypassing the problem. Unfortunately,          other than 2 because of this, bypassing the problem. Unfortunately,
1270          there was also a test in test 3 (the locale tests) that used /B and          there was also a test in test 3 (the locale tests) that used /B and
1271          failed for link sizes other than 2. Rather than cut the whole test out,          failed for link sizes other than 2. Rather than cut the whole test out,
1272          I have added a new /Z option to pcretest that replaces the length and          I have added a new /Z option to pcretest that replaces the length and
1273          offset values with spaces. This is now used to make test 3 independent          offset values with spaces. This is now used to make test 3 independent
1274          of link size. (Test 2 will be tidied up later.)          of link size. (Test 2 will be tidied up later.)
1275    
1276  14. If erroroffset was passed as NULL to pcre_compile, it provoked a  14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1277      segmentation fault instead of returning the appropriate error message.      segmentation fault instead of returning the appropriate error message.
1278    
1279    15. In multiline mode when the newline sequence was set to "any", the pattern
1280        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1281        This doesn't seem right; it now treats the CRLF combination as the line
1282        ending, and so does not match in that case. It's only a pattern such as ^$
1283        that would hit this one: something like ^ABC$ would have failed after \r
1284        and then tried again after \r\n.
1285    
1286    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1287        in an attempt to make files that differ only in their line terminators
1288        compare equal. This works on Linux.
1289    
1290    17. Under certain error circumstances pcregrep might try to free random memory
1291        as it exited. This is now fixed, thanks to valgrind.
1292    
1293    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1294        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1295        was because its rules for how to advance for /g after matching an empty
1296        string at the end of a line did not allow for this case. They now check for
1297        it specially.
1298    
1299    20. pcretest is supposed to handle patterns and data of any length, by
1300        extending its buffers when necessary. It was getting this wrong when the
1301        buffer for a data line had to be extended.
1302    
1303    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1304        CRLF as a newline sequence.
1305    
1306    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1307        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1308        I have nevertheless tidied it up.
1309    
1310    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1311    
1312    24. Added a man page for pcre-config.
1313    
1314    
1315  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1316  ---------------------  ---------------------

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