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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.02 01-Mar-2010
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
9    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
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.
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.
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".
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.
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).
33    8.  Following on from 7, I added a similar kludge to check the length of the
34        eint vector in pcreposix.c.
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.
42    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
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.
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.
56    Version 8.01 19-Jan-2010
57    ------------------------
59    1.  If a pattern contained a conditional subpattern with only one branch (in
60        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
61        computed the wrong minimum data length (which is of course zero for such
62        subpatterns). This could cause incorrect "no match" results.
64    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
65        the pattern is reset in the first branch, pcre_compile() failed with
66        "internal error: code overflow at offset...". This happened only when
67        the reset was to the original external option setting. (An optimization
68        abstracts leading options settings into an external setting, which was the
69        cause of this.)
71    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
72        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
73        assertion pattern did not match (meaning that the assertion was true), it
74        was incorrectly treated as false if the SKIP had been reached during the
75        matching. This also applied to assertions used as conditions.
77    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
78        assertion subpattern, including such a pattern used as a condition,
79        unpredictable results occurred, instead of the error return
82    5.  The C++ GlobalReplace function was not working like Perl for the special
83        situation when an empty string is matched. It now does the fancy magic
84        stuff that is necessary.
86    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
87        removed. (These were left over from very, very early versions of PCRE.)
89    7.  Some cosmetic changes to the code to make life easier when compiling it
90        as part of something else:
92        (a) Change DEBUG to PCRE_DEBUG.
94        (b) In pcre_compile(), rename the member of the "branch_chain" structure
95            called "current" as "current_branch", to prevent a collision with the
96            Linux macro when compiled as a kernel module.
98        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
99            prevent a collision with the Linux macro when compiled as a kernel
100            module.
102    8.  In pcre_compile() there are some checks for integer overflows that used to
103        cast potentially large values to (double). This has been changed to that
104        when building, a check for int64_t is made, and if it is found, it is used
105        instead, thus avoiding the use of floating point arithmetic. (There is no
106        other use of FP in PCRE.) If int64_t is not found, the fallback is to
107        double.
109    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
110        2005 (difference between two addresses compared to an unsigned value).
112    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
113        custom one, because of the following reported problem in Windows:
115          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
116              under Win32.
117          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
118              therefore missing the function definition.
119          - The compiler thus generates a "C" signature for the test function.
120          - The linker fails to find the "C" function.
121          - PCRE fails to configure if asked to do so against libbz2.
123    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
124        messages were output:
126          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
127          rerunning libtoolize, to keep the correct libtool macros in-tree.
128          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
130        I have done both of these things.
132    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
133        most of the time, it *can* run out if it is given a pattern that contains a
134        runaway infinite recursion. I updated the discussion in the pcrestack man
135        page.
137    13. Now that we have gone to the x.xx style of version numbers, the minor
138        version may start with zero. Using 08 or 09 is a bad idea because users
139        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
140        interpreted as invalid octal numbers. I've updated the previous comment in
141        configure.ac, and also added a check that gives an error if 08 or 09 are
142        used.
144    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
145        causing partial matching to fail when the end of the subject matched \W
146        in a UTF-8 pattern where \W was quantified with a minimum of 3.
148    15. There were some discrepancies between the declarations in pcre_internal.h
149        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
150        their definitions. The declarations used "const uschar *" and the
151        definitions used USPTR. Even though USPTR is normally defined as "const
152        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
153        reported that: "This difference in casting confuses some C++ compilers, for
154        example, SunCC recognizes above declarations as different functions and
155        generates broken code for hbpcre." I have changed the declarations to use
156        USPTR.
158    16. GNU libtool is named differently on some systems. The autogen.sh script now
159        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
160        (FreeBSD).
162    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
163        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
164        comment: "Figure out how to create a longlong from a string: strtoll and
165        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
166        instance, but it only takes 2 args instead of 3!"
168    18. A subtle bug concerned with back references has been fixed by a change of
169        specification, with a corresponding code fix. A pattern such as
170        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
171        refers, was giving matches when it shouldn't. For example, xa=xaaa would
172        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
173        same bug. Such groups have to be quantified to be useful, or contained
174        inside another quantified group. (If there's no repetition, the reference
175        can never match.) The problem arises because, having left the group and
176        moved on to the rest of the pattern, a later failure that backtracks into
177        the group uses the captured value from the final iteration of the group
178        rather than the correct earlier one. I have fixed this in PCRE by forcing
179        any group that contains a reference to itself to be an atomic group; that
180        is, there cannot be any backtracking into it once it has completed. This is
181        similar to recursive and subroutine calls.
184    Version 8.00 19-Oct-09
185    ----------------------
187    1.  The table for translating pcre_compile() error codes into POSIX error codes
188        was out-of-date, and there was no check on the pcre_compile() error code
189        being within the table. This could lead to an OK return being given in
190        error.
192    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
193        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
194        in a Windows environment.
196    3.  The pcregrep --count option prints the count for each file even when it is
197        zero, as does GNU grep. However, pcregrep was also printing all files when
198        --files-with-matches was added. Now, when both options are given, it prints
199        counts only for those files that have at least one match. (GNU grep just
200        prints the file name in this circumstance, but including the count seems
201        more useful - otherwise, why use --count?) Also ensured that the
202        combination -clh just lists non-zero counts, with no names.
204    4.  The long form of the pcregrep -F option was incorrectly implemented as
205        --fixed_strings instead of --fixed-strings. This is an incompatible change,
206        but it seems right to fix it, and I didn't think it was worth preserving
207        the old behaviour.
209    5.  The command line items --regex=pattern and --regexp=pattern were not
210        recognized by pcregrep, which required --regex pattern or --regexp pattern
211        (with a space rather than an '='). The man page documented the '=' forms,
212        which are compatible with GNU grep; these now work.
214    6.  No libpcreposix.pc file was created for pkg-config; there was just
215        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
217    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
218        when UCP support is not needed, by modifying the Python script that
219        generates it from Unicode data files. This should not matter if the module
220        is correctly used as a library, but I received one complaint about 50K of
221        unwanted data. My guess is that the person linked everything into his
222        program rather than using a library. Anyway, it does no harm.
224    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
225        was a minimum greater than 1 for a wide character in a possessive
226        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
227        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
228        character. Chaos in the form of incorrect output or a compiling loop could
229        result.
231    9.  The restrictions on what a pattern can contain when partial matching is
232        requested for pcre_exec() have been removed. All patterns can now be
233        partially matched by this function. In addition, if there are at least two
234        slots in the offset vector, the offset of the earliest inspected character
235        for the match and the offset of the end of the subject are set in them when
236        PCRE_ERROR_PARTIAL is returned.
238    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
239        synonymous with PCRE_PARTIAL, for backwards compatibility, and
240        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
241        and may be more useful for multi-segment matching.
243    11. Partial matching with pcre_exec() is now more intuitive. A partial match
244        used to be given if ever the end of the subject was reached; now it is
245        given only if matching could not proceed because another character was
246        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
247        string "Z", which now yields "no match" instead of "partial match". In the
248        case of pcre_dfa_exec(), "no match" is given if every matching path for the
249        final character ended with (*FAIL).
251    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
252        if the pattern had a "must contain" character that was already found in the
253        earlier partial match, unless partial matching was again requested. For
254        example, with the pattern /dog.(body)?/, the "must contain" character is
255        "g". If the first part-match was for the string "dog", restarting with
256        "sbody" failed. This bug has been fixed.
258    13. The string returned by pcre_dfa_exec() after a partial match has been
259        changed so that it starts at the first inspected character rather than the
260        first character of the match. This makes a difference only if the pattern
261        starts with a lookbehind assertion or \b or \B (\K is not supported by
262        pcre_dfa_exec()). It's an incompatible change, but it makes the two
263        matching functions compatible, and I think it's the right thing to do.
265    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
266        so that the demonstration program is easily available in environments where
267        PCRE has not been installed from source.
269    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
270        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
271        library.
273    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
274        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
275        is not the first non-POSIX option to be added. Clearly some people find
276        these options useful.
278    17. If a caller to the POSIX matching function regexec() passes a non-zero
279        value for nmatch with a NULL value for pmatch, the value of
280        nmatch is forced to zero.
282    18. RunGrepTest did not have a test for the availability of the -u option of
283        the diff command, as RunTest does. It now checks in the same way as
284        RunTest, and also checks for the -b option.
286    19. If an odd number of negated classes containing just a single character
287        interposed, within parentheses, between a forward reference to a named
288        subpattern and the definition of the subpattern, compilation crashed with
289        an internal error, complaining that it could not find the referenced
290        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
291        [The bug was that it was starting one character too far in when skipping
292        over the character class, thus treating the ] as data rather than
293        terminating the class. This meant it could skip too much.]
295    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
296        /g option in pcretest when the pattern contains \K, which makes it possible
297        to have an empty string match not at the start, even when the pattern is
298        anchored. Updated pcretest and pcredemo to use this option.
300    21. If the maximum number of capturing subpatterns in a recursion was greater
301        than the maximum at the outer level, the higher number was returned, but
302        with unset values at the outer level. The correct (outer level) value is
303        now given.
305    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
306        PCRE did not set those parentheses (unlike Perl). I have now found a way to
307        make it do so. The string so far is captured, making this feature
308        compatible with Perl.
310    23. The tests have been re-organized, adding tests 11 and 12, to make it
311        possible to check the Perl 5.10 features against Perl 5.10.
313    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
314        pattern matches a fixed length string. PCRE did not allow this; now it
315        does. Neither allows recursion.
317    25. I finally figured out how to implement a request to provide the minimum
318        length of subject string that was needed in order to match a given pattern.
319        (It was back references and recursion that I had previously got hung up
320        on.) This code has now been added to pcre_study(); it finds a lower bound
321        to the length of subject needed. It is not necessarily the greatest lower
322        bound, but using it to avoid searching strings that are too short does give
323        some useful speed-ups. The value is available to calling programs via
324        pcre_fullinfo().
326    26. While implementing 25, I discovered to my embarrassment that pcretest had
327        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
328        study optimizations had never been tested with that matching function.
329        Oops. What is worse, even when it was passed study data, there was a bug in
330        pcre_dfa_exec() that meant it never actually used it. Double oops. There
331        were also very few tests of studied patterns with pcre_dfa_exec().
333    27. If (?| is used to create subpatterns with duplicate numbers, they are now
334        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
335        on the other side of the coin, they are no longer allowed to have different
336        names, because these cannot be distinguished in PCRE, and this has caused
337        confusion. (This is a difference from Perl.)
339    28. When duplicate subpattern names are present (necessarily with different
340        numbers, as required by 27 above), and a test is made by name in a
341        conditional pattern, either for a subpattern having been matched, or for
342        recursion in such a pattern, all the associated numbered subpatterns are
343        tested, and the overall condition is true if the condition is true for any
344        one of them. This is the way Perl works, and is also more like the way
345        testing by number works.
348    Version 7.9 11-Apr-09
349    ---------------------
351    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
352        (pcretest), all targets were linked against these libraries. This included
353        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
354        libraries. This caused unwanted dependencies to be created. This problem
355        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
356        pcretest is linked with readline.
358    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
359        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
360        moved outside it again, because FALSE and TRUE are already defined in AIX,
361        but BOOL is not.
363    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
364        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
366    4.  The pcregrep documentation said spaces were inserted as well as colons (or
367        hyphens) following file names and line numbers when outputting matching
368        lines. This is not true; no spaces are inserted. I have also clarified the
369        wording for the --colour (or --color) option.
371    5.  In pcregrep, when --colour was used with -o, the list of matching strings
372        was not coloured; this is different to GNU grep, so I have changed it to be
373        the same.
375    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
376        each matching line was coloured. Now it goes on to look for further matches
377        of any of the test patterns, which is the same behaviour as GNU grep.
379    7.  A pattern that could match an empty string could cause pcregrep to loop; it
380        doesn't make sense to accept an empty string match in pcregrep, so I have
381        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
382        seems to be how GNU grep behaves.
384    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
385        start or after a newline", because the conditional assertion was not being
386        correctly handled. The rule now is that both the assertion and what follows
387        in the first alternative must satisfy the test.
389    9.  If auto-callout was enabled in a pattern with a conditional group whose
390        condition was an assertion, PCRE could crash during matching, both with
391        pcre_exec() and pcre_dfa_exec().
393    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
394        used for matching.
396    11. Unicode property support in character classes was not working for
397        characters (bytes) greater than 127 when not in UTF-8 mode.
399    12. Added the -M command line option to pcretest.
401    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
403    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
405    16. Added comments and documentation about mis-use of no_arg in the C++
406        wrapper.
408    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
409        from Martin Jerabek that uses macro names for all relevant character and
410        string constants.
412    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
413        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
414        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
415        these, but not everybody uses configure.
417    19. A conditional group that had only one branch was not being correctly
418        recognized as an item that could match an empty string. This meant that an
419        enclosing group might also not be so recognized, causing infinite looping
420        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
421        with the subject "ab", where knowledge that the repeated group can match
422        nothing is needed in order to break the loop.
424    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
425        exec(), but without supplying a callout function, matching went wrong.
427    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
428        leak if the size of the offset vector was greater than 30. When the vector
429        is smaller, the saved offsets during recursion go onto a local stack
430        vector, but for larger vectors malloc() is used. It was failing to free
431        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
432        error, in fact).
434    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
435        heapframe that is used only when UTF-8 support is enabled. This caused no
436        problem, but was untidy.
438    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
439        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
440        included within another project.
442    24. Steven Van Ingelgem's patches to add more options to the CMake support,
443        slightly modified by me:
445          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
446              not building pcregrep.
448          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
449              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
451    25. Forward references, both numeric and by name, in patterns that made use of
452        duplicate group numbers, could behave incorrectly or give incorrect errors,
453        because when scanning forward to find the reference group, PCRE was not
454        taking into account the duplicate group numbers. A pattern such as
455        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
457    26. Changed a few more instances of "const unsigned char *" to USPTR, making
458        the feature of a custom pointer more persuasive (as requested by a user).
460    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
461        pcretest.c, inside #ifndefs, because it seems they are sometimes already
462        pre-defined.
464    28. Added support for (*UTF8) at the start of a pattern.
466    29. Arrange for flags added by the "release type" setting in CMake to be shown
467        in the configuration summary.
470    Version 7.8 05-Sep-08
471    ---------------------
473    1.  Replaced UCP searching code with optimized version as implemented for Ad
474        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
475        stage table and inline lookup instead of a function, giving speed ups of 2
476        to 5 times on some simple patterns that I tested. Permission was given to
477        distribute the MultiStage2.py script that generates the tables (it's not in
478        the tarball, but is in the Subversion repository).
480    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
481        scripts.
483    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
484        a group with a zero qualifier. The result of the study could be incorrect,
485        or the function might crash, depending on the pattern.
487    4.  Caseless matching was not working for non-ASCII characters in back
488        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
489        It now works when Unicode Property Support is available.
491    5.  In pcretest, an escape such as \x{de} in the data was always generating
492        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
493        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
494        truncation.
496    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
498    7.  Added two (int) casts to pcregrep when printing the difference of two
499        pointers, in case they are 64-bit values.
501    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
502        test 2 if it fails.
504    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
505        and a #define of that name to empty if it is not externally set. This is to
506        allow users of MSVC to set it if necessary.
508    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
509        the convenience functions in the pcre_get.c source file.
511    11. An option change at the start of a pattern that had top-level alternatives
512        could cause overwriting and/or a crash. This command provoked a crash in
513        some environments:
515          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
517        This potential security problem was recorded as CVE-2008-2371.
519    12. For a pattern where the match had to start at the beginning or immediately
520        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
521        pcre_dfa_exec() could read past the end of the passed subject if there was
522        no match. To help with detecting such bugs (e.g. with valgrind), I modified
523        pcretest so that it places the subject at the end of its malloc-ed buffer.
525    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
526        exec() might read past the end of the data buffer in UTF-8 mode.
528    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
529        the data contained the byte 0x85 as part of a UTF-8 character within its
530        first line. This applied both to normal and DFA matching.
532    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
533        /^[^d]*?$/8 failed to match "abc".
535    16. Added a missing copyright notice to pcrecpp_internal.h.
537    17. Make it more clear in the documentation that values returned from
538        pcre_exec() in ovector are byte offsets, not character counts.
540    18. Tidied a few places to stop certain compilers from issuing warnings.
542    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
543        supplied by Stefan Weber. I made a further small update for 7.8 because
544        there is a change of source arrangements: the pcre_searchfuncs.c module is
545        replaced by pcre_ucd.c.
548    Version 7.7 07-May-08
549    ---------------------
551    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
552        a string to a long long, pretend we don't even have a long long." This is
553        done by checking for the strtoq, strtoll, and _strtoi64 functions.
555    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
556        pre-7.6 versions, which defined a global no_arg variable instead of putting
557        it in the RE class. (See also #8 below.)
559    3.  Remove a line of dead code, identified by coverity and reported by Nuno
560        Lopes.
562    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
564        (1) The include/exclude patterns were being applied to the whole pathnames
565            of files, instead of just to the final components.
567        (2) If there was more than one level of directory, the subdirectories were
568            skipped unless they satisfied the include/exclude conditions. This is
569            inconsistent with GNU grep (and could even be seen as contrary to the
570            pcregrep specification - which I improved to make it absolutely clear).
571            The action now is always to scan all levels of directory, and just
572            apply the include/exclude patterns to regular files.
574    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
575        --exclude_dir in the tests to avoid scanning .svn directories.
577    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
578        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
579        doesn't support NULs in patterns.
581    7.  Added some missing "const"s to declarations of static tables in
582        pcre_compile.c and pcre_dfa_exec.c.
584    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
585        caused by fix #2  above. (Subsequently also a second patch to fix the
586        first patch. And a third patch - this was a messy problem.)
588    9.  Applied Craig's patch to remove the use of push_back().
590    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
591        matching function regexec().
593    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
594        which, however, unlike Perl's \g{...}, are subroutine calls, not back
595        references. PCRE supports relative numbers with this syntax (I don't think
596        Oniguruma does).
598    12. Previously, a group with a zero repeat such as (...){0} was completely
599        omitted from the compiled regex. However, this means that if the group
600        was called as a subroutine from elsewhere in the pattern, things went wrong
601        (an internal error was given). Such groups are now left in the compiled
602        pattern, with a new opcode that causes them to be skipped at execution
603        time.
605    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
606        to the way PCRE behaves:
608        (a) A lone ] character is dis-allowed (Perl treats it as data).
610        (b) A back reference to an unmatched subpattern matches an empty string
611            (Perl fails the current match path).
613        (c) A data ] in a character class must be notated as \] because if the
614            first data character in a class is ], it defines an empty class. (In
615            Perl it is not possible to have an empty class.) The empty class []
616            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
617            The negative empty class [^] matches any one character, independently
618            of the DOTALL setting.
620    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
621        non-existent subpattern following a character class starting with ']' and
622        containing () gave an internal compiling error instead of "reference to
623        non-existent subpattern". Fortunately, when the pattern did exist, the
624        compiled code was correct. (When scanning forwards to check for the
625        existencd of the subpattern, it was treating the data ']' as terminating
626        the class, so got the count wrong. When actually compiling, the reference
627        was subsequently set up correctly.)
629    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
630        it was being rejected as not supported by pcre_dfa_exec(), even though
631        other assertions are supported. I have made pcre_dfa_exec() support
632        (*FAIL).
634    16. The implementation of 13c above involved the invention of a new opcode,
635        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
636        cannot be changed at match time, I realized I could make a small
637        improvement to matching performance by compiling OP_ALLANY instead of
638        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
639        on the OP_ANY path.
641    17. Compiling pcretest on Windows with readline support failed without the
642        following two fixes: (1) Make the unistd.h include conditional on
643        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
645    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
646        ncurses library to be included for pcretest when ReadLine support is
647        requested, but also to allow for it to be overridden. This patch came from
648        Daniel Bergström.
650    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
651        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
652        any errors with the current Unicode tables. Thanks to Peter Kankowski for
653        spotting this.
656    Version 7.6 28-Jan-08
657    ---------------------
659    1.  A character class containing a very large number of characters with
660        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
661        overflow.
663    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
664        HAVE_LONG_LONG is not defined.
666    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
667        bring them up to date and include new features. This patch includes:
669        - Fixed PH's badly added libz and libbz2 support.
670        - Fixed a problem with static linking.
671        - Added pcredemo. [But later removed - see 7 below.]
672        - Fixed dftables problem and added an option.
673        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
674            HAVE_LONG_LONG.
675        - Added readline support for pcretest.
676        - Added an listing of the option settings after cmake has run.
678    4.  A user submitted a patch to Makefile that makes it easy to create
679        "pcre.dll" under mingw when using Configure/Make. I added stuff to
680        Makefile.am that cause it to include this special target, without
681        affecting anything else. Note that the same mingw target plus all
682        the other distribution libraries and programs are now supported
683        when configuring with CMake (see 6 below) instead of with
684        Configure/Make.
686    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
687        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
688        exported in the Windows port". It has not yet been confirmed that the patch
689        solves the problem, but it does no harm.
691    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
692        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
693        with CMake, and also correct the comment about stack recursion.
695    7.  Remove the automatic building of pcredemo from the ./configure system and
696        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
697        of a program that users should build themselves after PCRE is installed, so
698        building it automatically is not really right. What is more, it gave
699        trouble in some build environments.
701    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
704    Version 7.5 10-Jan-08
705    ---------------------
707    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
708        values in parens when parsing an RE using the C++ wrapper."
710    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
711        Characters greater than 255 were excluded from the class instead of being
712        included.
714    3.  The same bug as (2) above applied to negated POSIX classes such as
715        [:^space:].
717    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
718        defined or documented. It seems to have been a typo for PCRE_STATIC, so
719        I have changed it.
721    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
722        first named subpattern) and a construct such as (?&a) would reference the
723        first named subpattern whose name started with "a" (in other words, the
724        length check was missing). Both these problems are fixed. "Subpattern name
725        expected" is now given for (?&) (a zero-length name), and this patch also
726        makes it give the same error for \k'' (previously it complained that that
727        was a reference to a non-existent subpattern).
729    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
730        this is right because (?- can be followed by option settings as well as by
731        digits. I have, however, made the messages clearer.
733    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
734        than the number used in the conditional) now cause a compile-time error.
735        This is actually not compatible with Perl, which accepts such patterns, but
736        treats the conditional as always being FALSE (as PCRE used to), but it
737        seems to me that giving a diagnostic is better.
739    8.  Change "alphameric" to the more common word "alphanumeric" in comments
740        and messages.
742    9.  Fix two occurrences of "backslash" in comments that should have been
743        "backspace".
745    10. Remove two redundant lines of code that can never be obeyed (their function
746        was moved elsewhere).
748    11. The program that makes PCRE's Unicode character property table had a bug
749        which caused it to generate incorrect table entries for sequences of
750        characters that have the same character type, but are in different scripts.
751        It amalgamated them into a single range, with the script of the first of
752        them. In other words, some characters were in the wrong script. There were
753        thirteen such cases, affecting characters in the following ranges:
755          U+002b0 - U+002c1
756          U+0060c - U+0060d
757          U+0061e - U+00612
758          U+0064b - U+0065e
759          U+0074d - U+0076d
760          U+01800 - U+01805
761          U+01d00 - U+01d77
762          U+01d9b - U+01dbf
763          U+0200b - U+0200f
764          U+030fc - U+030fe
765          U+03260 - U+0327f
766          U+0fb46 - U+0fbb1
767          U+10450 - U+1049d
769    12. The -o option (show only the matching part of a line) for pcregrep was not
770        compatible with GNU grep in that, if there was more than one match in a
771        line, it showed only the first of them. It now behaves in the same way as
772        GNU grep.
774    13. If the -o and -v options were combined for pcregrep, it printed a blank
775        line for every non-matching line. GNU grep prints nothing, and pcregrep now
776        does the same. The return code can be used to tell if there were any
777        non-matching lines.
779    14. Added --file-offsets and --line-offsets to pcregrep.
781    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
782        infinitely looping recursion. The bug was that positive lookaheads were not
783        being skipped when checking for a possible empty match (negative lookaheads
784        and both kinds of lookbehind were skipped).
786    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
787        inclusion of <windows.h> to before rather than after the definition of
788        INVALID_FILE_ATTRIBUTES (patch from David Byron).
790    17. Specifying a possessive quantifier with a specific limit for a Unicode
791        character property caused pcre_compile() to compile bad code, which led at
792        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
793        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
794        caused the error; without that there was no problem.
796    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
798    19. Added --enable-pcretest-libreadline.
800    20. In pcrecpp.cc, the variable 'count' was incremented twice in
801        RE::GlobalReplace(). As a result, the number of replacements returned was
802        double what it should be. I removed one of the increments, but Craig sent a
803        later patch that removed the other one (the right fix) and added unit tests
804        that check the return values (which was not done before).
806    21. Several CMake things:
808        (1) Arranged that, when cmake is used on Unix, the libraries end up with
809            the names libpcre and libpcreposix, not just pcre and pcreposix.
811        (2) The above change means that pcretest and pcregrep are now correctly
812            linked with the newly-built libraries, not previously installed ones.
816    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
817        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
818        UTF-8 newline character). The key issue is that the pattern starts .*;
819        this means that the match must be either at the beginning, or after a
820        newline. The bug was in the code for advancing after a failed match and
821        checking that the new position followed a newline. It was not taking
822        account of UTF-8 characters correctly.
824    23. PCRE was behaving differently from Perl in the way it recognized POSIX
825        character classes. PCRE was not treating the sequence [:...:] as a
826        character class unless the ... were all letters. Perl, however, seems to
827        allow any characters between [: and :], though of course it rejects as
828        unknown any "names" that contain non-letters, because all the known class
829        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
830        for example, whereas PCRE did not - it did not recognize a POSIX character
831        class. This seemed a bit dangerous, so the code has been changed to be
832        closer to Perl. The behaviour is not identical to Perl, because PCRE will
833        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
834        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
835        Perl does, and where it didn't before.
837    24. Rewrite so as to remove the single use of %n from pcregrep because in some
838        Windows environments %n is disabled by default.
841    Version 7.4 21-Sep-07
842    ---------------------
844    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
845        means that a class such as [\s] counted as "explicit reference to CR or
846        LF". That isn't really right - the whole point of the change was to try to
847        help when there was an actual mention of one of the two characters. So now
848        the change happens only if \r or \n (or a literal CR or LF) character is
849        encountered.
851    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
852        of both had grown to the point where there were only 3 bits left.
853        Fortunately, there was spare space in the data structure, and so I have
854        moved the internal flags into a new 16-bit field to free up more option
855        bits.
857    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
858        but did not set the internal JCHANGED flag - either of these is enough to
859        control the way the "get" function works - but the PCRE_INFO_JCHANGED
860        facility is supposed to tell if (?J) was ever used, so now (?J) at the
861        start sets both bits.
863    4.  Added options (at build time, compile time, exec time) to change \R from
864        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
866    5.  doc/pcresyntax.html was missing from the distribution.
868    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
869        compatibility, even though it is no longer used.
871    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
872        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
873        windows.h file is present (where different names are used). [This was
874        reversed later after testing - see 16 below.]
876    8.  Changed all #include <config.h> to #include "config.h". There were also
877        some further <pcre.h> cases that I changed to "pcre.h".
879    9.  When pcregrep was used with the --colour option, it missed the line ending
880        sequence off the lines that it output.
882    10. It was pointed out to me that arrays of string pointers cause lots of
883        relocations when a shared library is dynamically loaded. A technique of
884        using a single long string with a table of offsets can drastically reduce
885        these. I have refactored PCRE in four places to do this. The result is
886        dramatic:
888          Originally:                          290
889          After changing UCP table:            187
890          After changing error message table:   43
891          After changing table of "verbs"       36
892          After changing table of Posix names   22
894        Thanks to the folks working on Gregex for glib for this insight.
896    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
897        unicode-properties was also set.
899    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
901    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
902        checked only for CRLF.
904    14. Added casts to pcretest.c to avoid compiler warnings.
906    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
908    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
909        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
910        entirely. This removes changes made in 7 above.
912    17. The CMake files have been updated, and there is now more information about
913        building with CMake in the NON-UNIX-USE document.
916    Version 7.3 28-Aug-07
917    ---------------------
919     1. In the rejigging of the build system that eventually resulted in 7.1, the
920        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
921        brackets there is not right, since it causes compilers to look for an
922        installed pcre.h, not the version that is in the source that is being
923        compiled (which of course may be different). I have changed it back to:
925          #include "pcre.h"
927        I have a vague recollection that the change was concerned with compiling in
928        different directories, but in the new build system, that is taken care of
929        by the VPATH setting the Makefile.
931     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
932        when the subject happened to end in the byte 0x85 (e.g. if the last
933        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
934        characters but of course it shouldn't be taken as a newline when it is part
935        of another character. The bug was that, for an unlimited repeat of . in
936        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
937        characters when looking for a newline.
939     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
941     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
942        in debug output.
944     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
945        long printing in the pcrecpp unittest when running under MinGW.
947     6. ESC_K was left out of the EBCDIC table.
949     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
950        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
951        limit also applies to "virtual nesting" when a pattern is recursive, and in
952        this case 1000 isn't so big. I have been able to remove this limit at the
953        expense of backing off one optimization in certain circumstances. Normally,
954        when pcre_exec() would call its internal match() function recursively and
955        immediately return the result unconditionally, it uses a "tail recursion"
956        feature to save stack. However, when a subpattern that can match an empty
957        string has an unlimited repetition quantifier, it no longer makes this
958        optimization. That gives it a stack frame in which to save the data for
959        checking that an empty string has been matched. Previously this was taken
960        from the 1000-entry workspace that had been reserved. So now there is no
961        explicit limit, but more stack is used.
963     8. Applied Daniel's patches to solve problems with the import/export magic
964        syntax that is required for Windows, and which was going wrong for the
965        pcreposix and pcrecpp parts of the library. These were overlooked when this
966        problem was solved for the main library.
968     9. There were some crude static tests to avoid integer overflow when computing
969        the size of patterns that contain repeated groups with explicit upper
970        limits. As the maximum quantifier is 65535, the maximum group length was
971        set at 30,000 so that the product of these two numbers did not overflow a
972        32-bit integer. However, it turns out that people want to use groups that
973        are longer than 30,000 bytes (though not repeat them that many times).
974        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
975        made it possible to implement the integer overflow checks in a much more
976        dynamic way, which I have now done. The artificial limitation on group
977        length has been removed - we now have only the limit on the total length of
978        the compiled pattern, which depends on the LINK_SIZE setting.
980    10. Fixed a bug in the documentation for get/copy named substring when
981        duplicate names are permitted. If none of the named substrings are set, the
982        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
983        empty string.
985    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
986        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
987        because the ] is interpreted as the first data character and the
988        terminating ] is not found. PCRE has been made compatible with Perl in this
989        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
990        cause memory overwriting.
992    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
993        string has been matched (to stop an infinite loop). It was not recognizing
994        a conditional subpattern that could match an empty string if that
995        subpattern was within another subpattern. For example, it looped when
996        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
997        condition was not nested. This bug has been fixed.
999    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1000        past the start of the subject in the presence of bytes with the top bit
1001        set, for example "\x8aBCD".
1003    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1004        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1006    14. Optimized (?!) to (*FAIL).
1008    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1009        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1010        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1011        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1012        does: it's just the validity check that is more restrictive.
1014    16. Inserted checks for integer overflows during escape sequence (backslash)
1015        processing, and also fixed erroneous offset values for syntax errors during
1016        backslash processing.
1018    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1019        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1021    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1022        caused an overrun.
1024    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1025        something other than just ASCII characters) inside a group that had an
1026        unlimited repeat caused a loop at compile time (while checking to see
1027        whether the group could match an empty string).
1029    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1030        [\P{Any}] did so. (Error in the code for printing property names.)
1032    21. An orphan \E inside a character class could cause a crash.
1034    22. A repeated capturing bracket such as (A)? could cause a wild memory
1035        reference during compilation.
1037    23. There are several functions in pcre_compile() that scan along a compiled
1038        expression for various reasons (e.g. to see if it's fixed length for look
1039        behind). There were bugs in these functions when a repeated \p or \P was
1040        present in the pattern. These operators have additional parameters compared
1041        with \d, etc, and these were not being taken into account when moving along
1042        the compiled data. Specifically:
1044        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1045            length.
1047        (b) An item such as \pL+ within a repeated group could cause crashes or
1048            loops.
1050        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1051            "reference to non-existent subpattern" error.
1053        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1055    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1056        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1058    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1060    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1061        character were causing crashes (broken optimization).
1063    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1064        \p or \P) caused a compile-time loop.
1066    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1067        break. For example, the unstudied pattern [\r\n]A does not match the string
1068        "\r\nA" because change 7.0/46 below moves the current point on by two
1069        characters after failing to match at the start. However, the pattern \nA
1070        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1071        the same is true. There doesn't seem any very clean way out of this, but
1072        what I have chosen to do makes the common cases work: PCRE now takes note
1073        of whether there can be an explicit match for \r or \n anywhere in the
1074        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1075        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1076        pattern has explicit CR or LF references.
1078    29. Added (*CR) etc for changing newline setting at start of pattern.
1081    Version 7.2 19-Jun-07
1082    ---------------------
1084     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1085        which is apparently normally available under Windows.
1087     2. Re-jig the pcregrep tests with different newline settings in an attempt
1088        to make them independent of the local environment's newline setting.
1090     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1092     4. Some of the "internals" tests were previously cut out when the link size
1093        was not 2, because the output contained actual offsets. The recent new
1094        "Z" feature of pcretest means that these can be cut out, making the tests
1095        usable with all link sizes.
1097     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1098        stack recursion. This gives a massive performance boost under BSD, but just
1099        a small improvement under Linux. However, it saves one field in the frame
1100        in all cases.
1102     6. Added more features from the forthcoming Perl 5.10:
1104        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1105            recursion call. It refers to the nth most recently opened parentheses.
1107        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1108            to be opened parentheses.
1110        (c) Conditions that refer to capturing parentheses can be specified
1111            relatively, for example, (?(-2)... or (?(+3)...
1113        (d) \K resets the start of the current match so that everything before
1114            is not part of it.
1116        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1118        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1119            reference syntax.
1121        (g) (?| introduces a group in which the numbering of parentheses in each
1122            alternative starts with the same number.
1124        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1126     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1129     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1130        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1131        for detecting groups that can match an empty string.
1133     9. A pattern with a very large number of alternatives (more than several
1134        hundred) was running out of internal workspace during the pre-compile
1135        phase, where pcre_compile() figures out how much memory will be needed. A
1136        bit of new cunning has reduced the workspace needed for groups with
1137        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1138        workspace instead of running out of the 4096 that are available.
1140    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1142    11. Applied patch from Google to remove an optimization that didn't quite work.
1143        The report of the bug said:
1145          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1146          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1147          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1149    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1150        it matched the wrong number of bytes.
1153    Version 7.1 24-Apr-07
1154    ---------------------
1156     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1157        that is more "standard", making use of automake and other Autotools. There
1158        is some re-arrangement of the files and adjustment of comments consequent
1159        on this.
1161     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1162        for recursive directory scanning broke on some systems because the files
1163        are not scanned in any specific order and on different systems the order
1164        was different. A call to "sort" has been inserted into RunGrepTest for the
1165        approprate test as a short-term fix. In the longer term there may be an
1166        alternative.
1168     3. I had an email from Eric Raymond about problems translating some of PCRE's
1169        man pages to HTML (despite the fact that I distribute HTML pages, some
1170        people do their own conversions for various reasons). The problems
1171        concerned the use of low-level troff macros .br and .in. I have therefore
1172        removed all such uses from the man pages (some were redundant, some could
1173        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1174        HTML has been updated to handle .nf/.fi and to complain if it encounters
1175        .br or .in.
1177     4. Updated comments in configure.ac that get placed in config.h.in and also
1178        arranged for config.h to be included in the distribution, with the name
1179        config.h.generic, for the benefit of those who have to compile without
1180        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1182     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1183        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1184        makevp.bat for the current PCRE, using the additional files
1185        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1187     6. A Windows user reported a minor discrepancy with test 2, which turned out
1188        to be caused by a trailing space on an input line that had got lost in his
1189        copy. The trailing space was an accident, so I've just removed it.
1191     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1192        that is needed.
1194     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1195        as "const" (a) because they are and (b) because it helps the PHP
1196        maintainers who have recently made a script to detect big data structures
1197        in the php code that should be moved to the .rodata section. I remembered
1198        to update Builducptable as well, so it won't revert if ucptable.h is ever
1199        re-created.
1201     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1202        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1203        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1204        support is not required. This saves 1.5-2K of code, which is important in
1205        some applications.
1207        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1208        so as not to refer to the tables, even though these functions will never be
1209        called when UTF-8 support is disabled. Otherwise there are problems with a
1210        shared library.
1212    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1214        (a) It was defining its arguments as char * instead of void *.
1216        (b) It was assuming that all moves were upwards in memory; this was true
1217            a long time ago when I wrote it, but is no longer the case.
1219        The emulated memove() is provided for those environments that have neither
1220        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1221        is clearly not the case, as these two bugs were recently reported.
1223    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1224        and Detrail to create the HTML documentation, the .txt form of the man
1225        pages, and it removes trailing spaces from listed files. It also creates
1226        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1227        case, it wraps all the #defines with #ifndefs. This script should be run
1228        before "make dist".
1230    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1231        with Unicode property support.
1233        (a) For a maximizing quantifier, if the two different cases of the
1234            character were of different lengths in their UTF-8 codings (there are
1235            some cases like this - I found 11), and the matching function had to
1236            back up over a mixture of the two cases, it incorrectly assumed they
1237            were both the same length.
1239        (b) When PCRE was configured to use the heap rather than the stack for
1240            recursion during matching, it was not correctly preserving the data for
1241            the other case of a UTF-8 character when checking ahead for a match
1242            while processing a minimizing repeat. If the check also involved
1243            matching a wide character, but failed, corruption could cause an
1244            erroneous result when trying to check for a repeat of the original
1245            character.
1247    13. Some tidying changes to the testing mechanism:
1249        (a) The RunTest script now detects the internal link size and whether there
1250            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1251            values substituted by "configure". (The RunGrepTest script already did
1252            this for UTF-8.) The configure.ac script no longer substitutes the
1253            relevant variables.
1255        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1256            with length and offset values. This means that the output is different
1257            for different internal link sizes. Test 2 is skipped for link sizes
1258            other than 2 because of this, bypassing the problem. Unfortunately,
1259            there was also a test in test 3 (the locale tests) that used /B and
1260            failed for link sizes other than 2. Rather than cut the whole test out,
1261            I have added a new /Z option to pcretest that replaces the length and
1262            offset values with spaces. This is now used to make test 3 independent
1263            of link size. (Test 2 will be tidied up later.)
1265    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1266        segmentation fault instead of returning the appropriate error message.
1268    15. In multiline mode when the newline sequence was set to "any", the pattern
1269        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1270        This doesn't seem right; it now treats the CRLF combination as the line
1271        ending, and so does not match in that case. It's only a pattern such as ^$
1272        that would hit this one: something like ^ABC$ would have failed after \r
1273        and then tried again after \r\n.
1275    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1276        in an attempt to make files that differ only in their line terminators
1277        compare equal. This works on Linux.
1279    17. Under certain error circumstances pcregrep might try to free random memory
1280        as it exited. This is now fixed, thanks to valgrind.
1282    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1283        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1284        was because its rules for how to advance for /g after matching an empty
1285        string at the end of a line did not allow for this case. They now check for
1286        it specially.
1288    20. pcretest is supposed to handle patterns and data of any length, by
1289        extending its buffers when necessary. It was getting this wrong when the
1290        buffer for a data line had to be extended.
1292    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1293        CRLF as a newline sequence.
1295    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1296        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1297        I have nevertheless tidied it up.
1299    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1301    24. Added a man page for pcre-config.
1304    Version 7.0 19-Dec-06
1305    ---------------------
1307     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1308        moving to gcc 4.1.1.
1310     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1311        sys/time.h, which is documented as needed for this function. It doesn't
1312        seem to matter on Linux, but it showed up on some releases of OS X.
1314     3. It seems that there are systems where bytes whose values are greater than
1315        127 match isprint() in the "C" locale. The "C" locale should be the
1316        default when a C program starts up. In most systems, only ASCII printing
1317        characters match isprint(). This difference caused the output from pcretest
1318        to vary, making some of the tests fail. I have changed pcretest so that:
1320        (a) When it is outputting text in the compiled version of a pattern, bytes
1321            other than 32-126 are always shown as hex escapes.
1323        (b) When it is outputting text that is a matched part of a subject string,
1324            it does the same, unless a different locale has been set for the match
1325            (using the /L modifier). In this case, it uses isprint() to decide.
1327     4. Fixed a major bug that caused incorrect computation of the amount of memory
1328        required for a compiled pattern when options that changed within the
1329        pattern affected the logic of the preliminary scan that determines the
1330        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1331        that the computed length was too small. The symptoms of this bug were
1332        either the PCRE error "internal error: code overflow" from pcre_compile(),
1333        or a glibc crash with a message such as "pcretest: free(): invalid next
1334        size (fast)". Examples of patterns that provoked this bug (shown in
1335        pcretest format) are:
1337          /(?-x: )/x
1338          /(?x)(?-x: \s*#\s*)/
1339          /((?i)[\x{c0}])/8
1340          /(?i:[\x{c0}])/8
1342        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1343        is now done differently.
1345     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1346        wrapper classes; (b) implement a new function in the C++ scanner that is
1347        more efficient than the old way of doing things because it avoids levels of
1348        recursion in the regex matching; (c) add a paragraph to the documentation
1349        for the FullMatch() function.
1351     6. The escape sequence \n was being treated as whatever was defined as
1352        "newline". Not only was this contrary to the documentation, which states
1353        that \n is character 10 (hex 0A), but it also went horribly wrong when
1354        "newline" was defined as CRLF. This has been fixed.
1356     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1357        was being set to -1 for the "end of line" case (supposedly a value that no
1358        character can have). Though this value is never used (the check for end of
1359        line is "zero bytes in current character"), it caused compiler complaints.
1360        I've changed it to 0xffffffff.
1362     8. In pcre_version.c, the version string was being built by a sequence of
1363        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1364        string (as it is for production releases) called a macro with an empty
1365        argument. The C standard says the result of this is undefined. The gcc
1366        compiler treats it as an empty string (which was what was wanted) but it is
1367        reported that Visual C gives an error. The source has been hacked around to
1368        avoid this problem.
1370     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1371        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1372        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1373        of them did).
1375    10. Originally, pcretest opened its input and output without "b"; then I was
1376        told that "b" was needed in some environments, so it was added for release
1377        5.0 to both the input and output. (It makes no difference on Unix-like
1378        systems.) Later I was told that it is wrong for the input on Windows. I've
1379        now abstracted the modes into two macros, to make it easier to fiddle with
1380        them, and removed "b" from the input mode under Windows.
1382    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1384    12. Added -help and --help to pcretest as an official way of being reminded
1385        of the options.
1387    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1388        and pcrecpp.cc because they annoy compilers at high warning levels.
1390    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1392    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1393        scripts are not C programs :-) and which was not noticed because it works
1394        on Linux.
1396    16. pcretest is supposed to handle any length of pattern and data line (as one
1397        line or as a continued sequence of lines) by extending its input buffer if
1398        necessary. This feature was broken for very long pattern lines, leading to
1399        a string of junk being passed to pcre_compile() if the pattern was longer
1400        than about 50K.
1402    17. I have done a major re-factoring of the way pcre_compile() computes the
1403        amount of memory needed for a compiled pattern. Previously, there was code
1404        that made a preliminary scan of the pattern in order to do this. That was
1405        OK when PCRE was new, but as the facilities have expanded, it has become
1406        harder and harder to keep it in step with the real compile phase, and there
1407        have been a number of bugs (see for example, 4 above). I have now found a
1408        cunning way of running the real compile function in a "fake" mode that
1409        enables it to compute how much memory it would need, while actually only
1410        ever using a few hundred bytes of working memory and without too many
1411        tests of the mode. This should make future maintenance and development
1412        easier. A side effect of this work is that the limit of 200 on the nesting
1413        depth of parentheses has been removed (though this was never a serious
1414        limitation, I suspect). However, there is a downside: pcre_compile() now
1415        runs more slowly than before (30% or more, depending on the pattern). I
1416        hope this isn't a big issue. There is no effect on runtime performance.
1418    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1419        newline (only possible for the last line of a file) and it was a
1420        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1422    19. Added additional timing features to pcretest. (1) The -tm option now times
1423        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1424        separate command line item, by a number that specifies the number of
1425        repeats to use when timing. The default is 50000; this gives better
1426        precision, but takes uncomfortably long for very large patterns.
1428    20. Extended pcre_study() to be more clever in cases where a branch of a
1429        subpattern has no definite first character. For example, (a*|b*)[cd] would
1430        previously give no result from pcre_study(). Now it recognizes that the
1431        first character must be a, b, c, or d.
1433    21. There was an incorrect error "recursive call could loop indefinitely" if
1434        a subpattern (or the entire pattern) that was being tested for matching an
1435        empty string contained only one non-empty item after a nested subpattern.
1436        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1437        incorrectly, because the \d was being skipped in the check.
1439    22. The pcretest program now has a new pattern option /B and a command line
1440        option -b, which is equivalent to adding /B to every pattern. This causes
1441        it to show the compiled bytecode, without the additional information that
1442        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1443        is the same as /B/I).
1445    23. A new optimization is now able automatically to treat some sequences such
1446        as a*b as a*+b. More specifically, if something simple (such as a character
1447        or a simple class like \d) has an unlimited quantifier, and is followed by
1448        something that cannot possibly match the quantified thing, the quantifier
1449        is automatically "possessified".
1451    24. A recursive reference to a subpattern whose number was greater than 39
1452        went wrong under certain circumstances in UTF-8 mode. This bug could also
1453        have affected the operation of pcre_study().
1455    25. Realized that a little bit of performance could be had by replacing
1456        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1458    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1460    27. Possessive quantifiers such as a++ were previously implemented by turning
1461        them into atomic groups such as ($>a+). Now they have their own opcodes,
1462        which improves performance. This includes the automatically created ones
1463        from 23 above.
1465    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1466        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1467        the first matched character to be a colon. This applied both to named and
1468        numbered groups.
1470    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1472    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1473        building PCRE on Windows easier, so I have included it in the distribution.
1475    31. There is now a check in pcretest against a ridiculously large number being
1476        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1477        loop, the loop is abandoned.
1479    32. Forward references to subpatterns in conditions such as (?(2)...) where
1480        subpattern 2 is defined later cause pcre_compile() to search forwards in
1481        the pattern for the relevant set of parentheses. This search went wrong
1482        when there were unescaped parentheses in a character class, parentheses
1483        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1485    33. "Subroutine" calls and backreferences were previously restricted to
1486        referencing subpatterns earlier in the regex. This restriction has now
1487        been removed.
1489    34. Added a number of extra features that are going to be in Perl 5.10. On the
1490        whole, these are just syntactic alternatives for features that PCRE had
1491        previously implemented using the Python syntax or my own invention. The
1492        other formats are all retained for compatibility.
1494        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1495            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1496            also .NET compatible.
1498        (b) A recursion or subroutine call to a named group can now be defined as
1499            (?&name) as well as (?P>name).
1501        (c) A backreference to a named group can now be defined as \k<name> or
1502            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1503            5.10, are also .NET compatible.
1505        (d) A conditional reference to a named group can now use the syntax
1506            (?(<name>) or (?('name') as well as (?(name).
1508        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1509            groups (named and numbered) that are never evaluated inline, but can be
1510            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1511            is always false. There may be only one alternative in such a group.
1513        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1514            as the simple (?(R). The condition is true only if the most recent
1515            recursion is that of the given number or name. It does not search out
1516            through the entire recursion stack.
1518        (g) The escape \gN or \g{N} has been added, where N is a positive or
1519            negative number, specifying an absolute or relative reference.
1521    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1522        some "unreachable code" warnings.
1524    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1525        things, this adds five new scripts.
1527    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1528        There were also incompatibilities regarding the handling of \Q..\E inside
1529        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1530        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1532    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1533        matches an empty string, and forcibly breaks the loop. There were bugs in
1534        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1535        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1536        separate and independent bugs (that affected different cases) have been
1537        fixed.
1539    39. Refactored the code to abolish the use of different opcodes for small
1540        capturing bracket numbers. This is a tidy that I avoided doing when I
1541        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1542        The new approach is not only tidier, it makes it possible to reduce the
1543        memory needed to fix the previous bug (38).
1545    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1546        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1547        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1548        mode.
1550    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1551        report.
1553    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1554        copy construction and assignment in the C++ wrapper.
1556    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1557        couple of bugs that could have given wrong results in the "--newline=crlf"
1558        case.
1560    44. Added a number of casts and did some reorganization of signed/unsigned int
1561        variables following suggestions from Dair Grant. Also renamed the variable
1562        "this" as "item" because it is a C++ keyword.
1564    45. Arranged for dftables to add
1566          #include "pcre_internal.h"
1568        to pcre_chartables.c because without it, gcc 4.x may remove the array
1569        definition from the final binary if PCRE is built into a static library and
1570        dead code stripping is activated.
1572    46. For an unanchored pattern, if a match attempt fails at the start of a
1573        newline sequence, and the newline setting is CRLF or ANY, and the next two
1574        characters are CRLF, advance by two characters instead of one.
1577    Version 6.7 04-Jul-06
1578    ---------------------
1580     1. In order to handle tests when input lines are enormously long, pcretest has
1581        been re-factored so that it automatically extends its buffers when
1582        necessary. The code is crude, but this _is_ just a test program. The
1583        default size has been increased from 32K to 50K.
1585     2. The code in pcre_study() was using the value of the re argument before
1586        testing it for NULL. (Of course, in any sensible call of the function, it
1587        won't be NULL.)
1589     3. The memmove() emulation function in pcre_internal.h, which is used on
1590        systems that lack both memmove() and bcopy() - that is, hardly ever -
1591        was missing a "static" storage class specifier.
1593     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1594        containing an extended class (one that cannot be represented by a bitmap
1595        because it contains high-valued characters or Unicode property items, e.g.
1596        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1597        pattern, but PCRE should not loop if you do not (it no longer does).
1598        [Detail: two cases were found: (a) a repeated subpattern containing an
1599        extended class; (b) a recursive reference to a subpattern that followed a
1600        previous extended class. It wasn't skipping over the extended class
1601        correctly when UTF-8 mode was not set.]
1603     5. A negated single-character class was not being recognized as fixed-length
1604        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1605        compile error "lookbehind assertion is not fixed length".
1607     6. The RunPerlTest auxiliary script was showing an unexpected difference
1608        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1609        write a Perl script that can interpret lines of an input file either as
1610        byte characters or as UTF-8, which is what "perltest" was being required to
1611        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1612        can't do is switch easily at run time between having the "use utf8;" pragma
1613        or not. In the end, I fudged it by using the RunPerlTest script to insert
1614        "use utf8;" explicitly for the UTF-8 tests.
1616     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1617        the end of the subject string, contrary to the documentation and to what
1618        Perl does. This was true of both matching functions. Now it matches only at
1619        the start of the subject and immediately after *internal* newlines.
1621     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1622        a pointer to an int instead of a pointer to an unsigned long int. This
1623        caused problems on 64-bit systems.
1625     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1626        instance of the 'standard' template library not being so standard".
1628    10. There was no check on the number of named subpatterns nor the maximum
1629        length of a subpattern name. The product of these values is used to compute
1630        the size of the memory block for a compiled pattern. By supplying a very
1631        long subpattern name and a large number of named subpatterns, the size
1632        computation could be caused to overflow. This is now prevented by limiting
1633        the length of names to 32 characters, and the number of named subpatterns
1634        to 10,000.
1636    11. Subpatterns that are repeated with specific counts have to be replicated in
1637        the compiled pattern. The size of memory for this was computed from the
1638        length of the subpattern and the repeat count. The latter is limited to
1639        65535, but there was no limit on the former, meaning that integer overflow
1640        could in principle occur. The compiled length of a repeated subpattern is
1641        now limited to 30,000 bytes in order to prevent this.
1643    12. Added the optional facility to have named substrings with the same name.
1645    13. Added the ability to use a named substring as a condition, using the
1646        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1647        are numbers (not recommended). Forward references are permitted.
1649    14. Added forward references in named backreferences (if you see what I mean).
1651    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1652        pattern could run off the end of the subject. For example, the pattern
1653        "(?s)(.{1,5})"8 did this with the subject "ab".
1655    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1656        PCRE_CASELESS was set when matching characters that were quantified with ?
1657        or *.
1659    17. A character class other than a single negated character that had a minimum
1660        but no maximum quantifier - for example [ab]{6,} - was not handled
1661        correctly by pce_dfa_exec(). It would match only one character.
1663    18. A valid (though odd) pattern that looked like a POSIX character
1664        class but used an invalid character after [ (for example [[,abc,]]) caused
1665        pcre_compile() to give the error "Failed: internal error: code overflow" or
1666        in some cases to crash with a glibc free() error. This could even happen if
1667        the pattern terminated after [[ but there just happened to be a sequence of
1668        letters, a binary zero, and a closing ] in the memory that followed.
1670    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1671        over the years. Originally (before any Unicode support), just the bottom 8
1672        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1673        output from "man perlunicode" includes this:
1675          The regular expression compiler produces polymorphic opcodes.  That
1676          is, the pattern adapts to the data and automatically switches to
1677          the Unicode character scheme when presented with Unicode data--or
1678          instead uses a traditional byte scheme when presented with byte
1679          data.
1681        Sadly, a wide octal escape does not cause a switch, and in a string with
1682        no other multibyte characters, these octal escapes are treated as before.
1683        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1684        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1685        Unicode string.
1687        I have not perpetrated such confusion in PCRE. Up till now, it took just
1688        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1689        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1690        translate to the appropriate multibyte character.
1692    29. Applied some refactoring to reduce the number of warnings from Microsoft
1693        and Borland compilers. This has included removing the fudge introduced
1694        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1695        a warning about an unused variable.
1697    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1698        characters since release 4.0, because Perl (from release 5.004) does not.
1699        [Or at least, is documented not to: some releases seem to be in conflict
1700        with the documentation.] However, when a pattern was studied with
1701        pcre_study() and all its branches started with \s, PCRE still included VT
1702        as a possible starting character. Of course, this did no harm; it just
1703        caused an unnecessary match attempt.
1705    22. Removed a now-redundant internal flag bit that recorded the fact that case
1706        dependency changed within the pattern. This was once needed for "required
1707        byte" processing, but is no longer used. This recovers a now-scarce options
1708        bit. Also moved the least significant internal flag bit to the most-
1709        significant bit of the word, which was not previously used (hangover from
1710        the days when it was an int rather than a uint) to free up another bit for
1711        the future.
1713    23. Added support for CRLF line endings as well as CR and LF. As well as the
1714        default being selectable at build time, it can now be changed at runtime
1715        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1716        specify that it is scanning data with non-default line endings.
1718    24. Changed the definition of CXXLINK to make it agree with the definition of
1719        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1721    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1722        recursions. This makes a big different to stack usage for some patterns.
1724    26. If a subpattern containing a named recursion or subroutine reference such
1725        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1726        the space required for the compiled pattern went wrong and gave too small a
1727        value. Depending on the environment, this could lead to "Failed: internal
1728        error: code overflow at offset 49" or "glibc detected double free or
1729        corruption" errors.
1731    27. Applied patches from Google (a) to support the new newline modes and (b) to
1732        advance over multibyte UTF-8 characters in GlobalReplace.
1734    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1735        difference for some implementation of PCRE in some Windows version.
1737    29. Added some extra testing facilities to pcretest:
1739        \q<number>   in a data line sets the "match limit" value
1740        \Q<number>   in a data line sets the "match recursion limt" value
1741        -S <number>  sets the stack size, where <number> is in megabytes
1743        The -S option isn't available for Windows.
1746    Version 6.6 06-Feb-06
1747    ---------------------
1749     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1750        in pcreposix.h. I have copied the definition from pcre.h.
1752     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1753        because pcre.h is no longer a built file.
1755     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1756        not normally included in the compiled code.
1759  Version 6.5 01-Feb-06  Version 6.5 01-Feb-06
1760  ---------------------  ---------------------

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