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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.10 03 May-2010
5    ------------------------
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
10    2.  (*ACCEPT) was not working when inside an atomic group.
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
29    7.  Minor change to pcretest.c to avoid a compiler warning.
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
40    10. Added --line-buffered to pcregrep.
42    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43        studied, and the match started with a letter with a code point greater than
44        127 whose first byte was different to the first byte of the other case of
45        the letter, the other case of this starting letter was not recognized.
47    12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48        conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49        pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50        historical tidying that never got done.)
52    13. If a pattern that was studied started with a repeated Unicode property
53        test, for example, \p{Nd}+, there was the theoretical possibility of
54        setting up an incorrect bitmap of starting bytes, but fortunately it could
55        not have actually happened in practice until change 8 above was made (it
56        added property types that matched character-matching opcodes).
58    14. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
59        possible starting bytes for non-anchored patterns.
61    15. The "auto-possessify" feature of pcre_compile() now recognizes \R.
63    16. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
64        input, it could crash or give wrong results if characters with values
65        greater than 0xc0 were present in the subject string. (Detail: it assumed
66        UTF-8 input when processing these items.)
68    17. Added a lot of (int) casts to avoid compiler warnings in systems where
69        size_t is 64-bit.
71    18. Added a check for running out of memory when PCRE is compiled with
72        --disable-stack-for-recursion.
76    Version 8.02 19-Mar-2010
77    ------------------------
79    1.  The Unicode data tables have been updated to Unicode 5.2.0.
81    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
82        configured.
84    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
85        original author of that file, following a query about its status.
87    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
88        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
90    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
91        quantifier applied to a forward-referencing subroutine call, could compile
92        incorrect code or give the error "internal error: previously-checked
93        referenced subpattern not found".
95    6.  Both MS Visual Studio and Symbian OS have problems with initializing
96        variables to point to external functions. For these systems, therefore,
97        pcre_malloc etc. are now initialized to local functions that call the
98        relevant global functions.
100    7.  There were two entries missing in the vectors called coptable and poptable
101        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
102        I've fixed the data, and added a kludgy way of testing at compile time that
103        the lengths are correct (equal to the number of opcodes).
105    8.  Following on from 7, I added a similar kludge to check the length of the
106        eint vector in pcreposix.c.
108    9.  Error texts for pcre_compile() are held as one long string to avoid too
109        much relocation at load time. To find a text, the string is searched,
110        counting zeros. There was no check for running off the end of the string,
111        which could happen if a new error number was added without updating the
112        string.
114    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
116    11. \K was not working if it appeared in an atomic group or in a group that
117        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
118        \K is "not well defined" if used in an assertion. PCRE now accepts it if
119        the assertion is positive, but not if it is negative.
121    12. Change 11 fortuitously reduced the size of the stack frame used in the
122        "match()" function of pcre_exec.c by one pointer. Forthcoming
123        implementation of support for (*MARK) will need an extra pointer on the
124        stack; I have reserved it now, so that the stack frame size does not
125        decrease.
127    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
128        item in branch that calls a recursion is a subroutine call - as in the
129        second branch in the above example - was incorrectly given the compile-
130        time error "recursive call could loop indefinitely" because pcre_compile()
131        was not correctly checking the subroutine for matching a non-empty string.
133    14. The checks for overrunning compiling workspace could trigger after an
134        overrun had occurred. This is a "should never occur" error, but it can be
135        triggered by pathological patterns such as hundreds of nested parentheses.
136        The checks now trigger 100 bytes before the end of the workspace.
138    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
141    Version 8.01 19-Jan-2010
142    ------------------------
144    1.  If a pattern contained a conditional subpattern with only one branch (in
145        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
146        computed the wrong minimum data length (which is of course zero for such
147        subpatterns). This could cause incorrect "no match" results.
149    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
150        the pattern is reset in the first branch, pcre_compile() failed with
151        "internal error: code overflow at offset...". This happened only when
152        the reset was to the original external option setting. (An optimization
153        abstracts leading options settings into an external setting, which was the
154        cause of this.)
156    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
157        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
158        assertion pattern did not match (meaning that the assertion was true), it
159        was incorrectly treated as false if the SKIP had been reached during the
160        matching. This also applied to assertions used as conditions.
162    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
163        assertion subpattern, including such a pattern used as a condition,
164        unpredictable results occurred, instead of the error return
167    5.  The C++ GlobalReplace function was not working like Perl for the special
168        situation when an empty string is matched. It now does the fancy magic
169        stuff that is necessary.
171    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
172        removed. (These were left over from very, very early versions of PCRE.)
174    7.  Some cosmetic changes to the code to make life easier when compiling it
175        as part of something else:
177        (a) Change DEBUG to PCRE_DEBUG.
179        (b) In pcre_compile(), rename the member of the "branch_chain" structure
180            called "current" as "current_branch", to prevent a collision with the
181            Linux macro when compiled as a kernel module.
183        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
184            prevent a collision with the Linux macro when compiled as a kernel
185            module.
187    8.  In pcre_compile() there are some checks for integer overflows that used to
188        cast potentially large values to (double). This has been changed to that
189        when building, a check for int64_t is made, and if it is found, it is used
190        instead, thus avoiding the use of floating point arithmetic. (There is no
191        other use of FP in PCRE.) If int64_t is not found, the fallback is to
192        double.
194    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
195        2005 (difference between two addresses compared to an unsigned value).
197    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
198        custom one, because of the following reported problem in Windows:
200          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
201              under Win32.
202          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
203              therefore missing the function definition.
204          - The compiler thus generates a "C" signature for the test function.
205          - The linker fails to find the "C" function.
206          - PCRE fails to configure if asked to do so against libbz2.
208    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
209        messages were output:
211          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
212          rerunning libtoolize, to keep the correct libtool macros in-tree.
213          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
215        I have done both of these things.
217    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
218        most of the time, it *can* run out if it is given a pattern that contains a
219        runaway infinite recursion. I updated the discussion in the pcrestack man
220        page.
222    13. Now that we have gone to the x.xx style of version numbers, the minor
223        version may start with zero. Using 08 or 09 is a bad idea because users
224        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
225        interpreted as invalid octal numbers. I've updated the previous comment in
226        configure.ac, and also added a check that gives an error if 08 or 09 are
227        used.
229    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
230        causing partial matching to fail when the end of the subject matched \W
231        in a UTF-8 pattern where \W was quantified with a minimum of 3.
233    15. There were some discrepancies between the declarations in pcre_internal.h
234        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
235        their definitions. The declarations used "const uschar *" and the
236        definitions used USPTR. Even though USPTR is normally defined as "const
237        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
238        reported that: "This difference in casting confuses some C++ compilers, for
239        example, SunCC recognizes above declarations as different functions and
240        generates broken code for hbpcre." I have changed the declarations to use
241        USPTR.
243    16. GNU libtool is named differently on some systems. The autogen.sh script now
244        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
245        (FreeBSD).
247    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
248        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
249        comment: "Figure out how to create a longlong from a string: strtoll and
250        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
251        instance, but it only takes 2 args instead of 3!"
253    18. A subtle bug concerned with back references has been fixed by a change of
254        specification, with a corresponding code fix. A pattern such as
255        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
256        refers, was giving matches when it shouldn't. For example, xa=xaaa would
257        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
258        same bug. Such groups have to be quantified to be useful, or contained
259        inside another quantified group. (If there's no repetition, the reference
260        can never match.) The problem arises because, having left the group and
261        moved on to the rest of the pattern, a later failure that backtracks into
262        the group uses the captured value from the final iteration of the group
263        rather than the correct earlier one. I have fixed this in PCRE by forcing
264        any group that contains a reference to itself to be an atomic group; that
265        is, there cannot be any backtracking into it once it has completed. This is
266        similar to recursive and subroutine calls.
269    Version 8.00 19-Oct-09
270    ----------------------
272    1.  The table for translating pcre_compile() error codes into POSIX error codes
273        was out-of-date, and there was no check on the pcre_compile() error code
274        being within the table. This could lead to an OK return being given in
275        error.
277    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
278        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
279        in a Windows environment.
281    3.  The pcregrep --count option prints the count for each file even when it is
282        zero, as does GNU grep. However, pcregrep was also printing all files when
283        --files-with-matches was added. Now, when both options are given, it prints
284        counts only for those files that have at least one match. (GNU grep just
285        prints the file name in this circumstance, but including the count seems
286        more useful - otherwise, why use --count?) Also ensured that the
287        combination -clh just lists non-zero counts, with no names.
289    4.  The long form of the pcregrep -F option was incorrectly implemented as
290        --fixed_strings instead of --fixed-strings. This is an incompatible change,
291        but it seems right to fix it, and I didn't think it was worth preserving
292        the old behaviour.
294    5.  The command line items --regex=pattern and --regexp=pattern were not
295        recognized by pcregrep, which required --regex pattern or --regexp pattern
296        (with a space rather than an '='). The man page documented the '=' forms,
297        which are compatible with GNU grep; these now work.
299    6.  No libpcreposix.pc file was created for pkg-config; there was just
300        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
302    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
303        when UCP support is not needed, by modifying the Python script that
304        generates it from Unicode data files. This should not matter if the module
305        is correctly used as a library, but I received one complaint about 50K of
306        unwanted data. My guess is that the person linked everything into his
307        program rather than using a library. Anyway, it does no harm.
309    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
310        was a minimum greater than 1 for a wide character in a possessive
311        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
312        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
313        character. Chaos in the form of incorrect output or a compiling loop could
314        result.
316    9.  The restrictions on what a pattern can contain when partial matching is
317        requested for pcre_exec() have been removed. All patterns can now be
318        partially matched by this function. In addition, if there are at least two
319        slots in the offset vector, the offset of the earliest inspected character
320        for the match and the offset of the end of the subject are set in them when
321        PCRE_ERROR_PARTIAL is returned.
323    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
324        synonymous with PCRE_PARTIAL, for backwards compatibility, and
325        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
326        and may be more useful for multi-segment matching.
328    11. Partial matching with pcre_exec() is now more intuitive. A partial match
329        used to be given if ever the end of the subject was reached; now it is
330        given only if matching could not proceed because another character was
331        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
332        string "Z", which now yields "no match" instead of "partial match". In the
333        case of pcre_dfa_exec(), "no match" is given if every matching path for the
334        final character ended with (*FAIL).
336    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
337        if the pattern had a "must contain" character that was already found in the
338        earlier partial match, unless partial matching was again requested. For
339        example, with the pattern /dog.(body)?/, the "must contain" character is
340        "g". If the first part-match was for the string "dog", restarting with
341        "sbody" failed. This bug has been fixed.
343    13. The string returned by pcre_dfa_exec() after a partial match has been
344        changed so that it starts at the first inspected character rather than the
345        first character of the match. This makes a difference only if the pattern
346        starts with a lookbehind assertion or \b or \B (\K is not supported by
347        pcre_dfa_exec()). It's an incompatible change, but it makes the two
348        matching functions compatible, and I think it's the right thing to do.
350    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
351        so that the demonstration program is easily available in environments where
352        PCRE has not been installed from source.
354    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
355        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
356        library.
358    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
359        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
360        is not the first non-POSIX option to be added. Clearly some people find
361        these options useful.
363    17. If a caller to the POSIX matching function regexec() passes a non-zero
364        value for nmatch with a NULL value for pmatch, the value of
365        nmatch is forced to zero.
367    18. RunGrepTest did not have a test for the availability of the -u option of
368        the diff command, as RunTest does. It now checks in the same way as
369        RunTest, and also checks for the -b option.
371    19. If an odd number of negated classes containing just a single character
372        interposed, within parentheses, between a forward reference to a named
373        subpattern and the definition of the subpattern, compilation crashed with
374        an internal error, complaining that it could not find the referenced
375        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
376        [The bug was that it was starting one character too far in when skipping
377        over the character class, thus treating the ] as data rather than
378        terminating the class. This meant it could skip too much.]
380    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
381        /g option in pcretest when the pattern contains \K, which makes it possible
382        to have an empty string match not at the start, even when the pattern is
383        anchored. Updated pcretest and pcredemo to use this option.
385    21. If the maximum number of capturing subpatterns in a recursion was greater
386        than the maximum at the outer level, the higher number was returned, but
387        with unset values at the outer level. The correct (outer level) value is
388        now given.
390    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
391        PCRE did not set those parentheses (unlike Perl). I have now found a way to
392        make it do so. The string so far is captured, making this feature
393        compatible with Perl.
395    23. The tests have been re-organized, adding tests 11 and 12, to make it
396        possible to check the Perl 5.10 features against Perl 5.10.
398    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
399        pattern matches a fixed length string. PCRE did not allow this; now it
400        does. Neither allows recursion.
402    25. I finally figured out how to implement a request to provide the minimum
403        length of subject string that was needed in order to match a given pattern.
404        (It was back references and recursion that I had previously got hung up
405        on.) This code has now been added to pcre_study(); it finds a lower bound
406        to the length of subject needed. It is not necessarily the greatest lower
407        bound, but using it to avoid searching strings that are too short does give
408        some useful speed-ups. The value is available to calling programs via
409        pcre_fullinfo().
411    26. While implementing 25, I discovered to my embarrassment that pcretest had
412        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
413        study optimizations had never been tested with that matching function.
414        Oops. What is worse, even when it was passed study data, there was a bug in
415        pcre_dfa_exec() that meant it never actually used it. Double oops. There
416        were also very few tests of studied patterns with pcre_dfa_exec().
418    27. If (?| is used to create subpatterns with duplicate numbers, they are now
419        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
420        on the other side of the coin, they are no longer allowed to have different
421        names, because these cannot be distinguished in PCRE, and this has caused
422        confusion. (This is a difference from Perl.)
424    28. When duplicate subpattern names are present (necessarily with different
425        numbers, as required by 27 above), and a test is made by name in a
426        conditional pattern, either for a subpattern having been matched, or for
427        recursion in such a pattern, all the associated numbered subpatterns are
428        tested, and the overall condition is true if the condition is true for any
429        one of them. This is the way Perl works, and is also more like the way
430        testing by number works.
433    Version 7.9 11-Apr-09
434    ---------------------
436    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
437        (pcretest), all targets were linked against these libraries. This included
438        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
439        libraries. This caused unwanted dependencies to be created. This problem
440        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
441        pcretest is linked with readline.
443    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
444        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
445        moved outside it again, because FALSE and TRUE are already defined in AIX,
446        but BOOL is not.
448    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
449        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
451    4.  The pcregrep documentation said spaces were inserted as well as colons (or
452        hyphens) following file names and line numbers when outputting matching
453        lines. This is not true; no spaces are inserted. I have also clarified the
454        wording for the --colour (or --color) option.
456    5.  In pcregrep, when --colour was used with -o, the list of matching strings
457        was not coloured; this is different to GNU grep, so I have changed it to be
458        the same.
460    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
461        each matching line was coloured. Now it goes on to look for further matches
462        of any of the test patterns, which is the same behaviour as GNU grep.
464    7.  A pattern that could match an empty string could cause pcregrep to loop; it
465        doesn't make sense to accept an empty string match in pcregrep, so I have
466        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
467        seems to be how GNU grep behaves.
469    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
470        start or after a newline", because the conditional assertion was not being
471        correctly handled. The rule now is that both the assertion and what follows
472        in the first alternative must satisfy the test.
474    9.  If auto-callout was enabled in a pattern with a conditional group whose
475        condition was an assertion, PCRE could crash during matching, both with
476        pcre_exec() and pcre_dfa_exec().
478    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
479        used for matching.
481    11. Unicode property support in character classes was not working for
482        characters (bytes) greater than 127 when not in UTF-8 mode.
484    12. Added the -M command line option to pcretest.
486    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
488    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
490    16. Added comments and documentation about mis-use of no_arg in the C++
491        wrapper.
493    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
494        from Martin Jerabek that uses macro names for all relevant character and
495        string constants.
497    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
498        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
499        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
500        these, but not everybody uses configure.
502    19. A conditional group that had only one branch was not being correctly
503        recognized as an item that could match an empty string. This meant that an
504        enclosing group might also not be so recognized, causing infinite looping
505        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
506        with the subject "ab", where knowledge that the repeated group can match
507        nothing is needed in order to break the loop.
509    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
510        exec(), but without supplying a callout function, matching went wrong.
512    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
513        leak if the size of the offset vector was greater than 30. When the vector
514        is smaller, the saved offsets during recursion go onto a local stack
515        vector, but for larger vectors malloc() is used. It was failing to free
516        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
517        error, in fact).
519    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
520        heapframe that is used only when UTF-8 support is enabled. This caused no
521        problem, but was untidy.
523    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
524        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
525        included within another project.
527    24. Steven Van Ingelgem's patches to add more options to the CMake support,
528        slightly modified by me:
530          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
531              not building pcregrep.
533          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
534              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
536    25. Forward references, both numeric and by name, in patterns that made use of
537        duplicate group numbers, could behave incorrectly or give incorrect errors,
538        because when scanning forward to find the reference group, PCRE was not
539        taking into account the duplicate group numbers. A pattern such as
540        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
542    26. Changed a few more instances of "const unsigned char *" to USPTR, making
543        the feature of a custom pointer more persuasive (as requested by a user).
545    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
546        pcretest.c, inside #ifndefs, because it seems they are sometimes already
547        pre-defined.
549    28. Added support for (*UTF8) at the start of a pattern.
551    29. Arrange for flags added by the "release type" setting in CMake to be shown
552        in the configuration summary.
555    Version 7.8 05-Sep-08
556    ---------------------
558    1.  Replaced UCP searching code with optimized version as implemented for Ad
559        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
560        stage table and inline lookup instead of a function, giving speed ups of 2
561        to 5 times on some simple patterns that I tested. Permission was given to
562        distribute the MultiStage2.py script that generates the tables (it's not in
563        the tarball, but is in the Subversion repository).
565    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
566        scripts.
568    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
569        a group with a zero qualifier. The result of the study could be incorrect,
570        or the function might crash, depending on the pattern.
572    4.  Caseless matching was not working for non-ASCII characters in back
573        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
574        It now works when Unicode Property Support is available.
576    5.  In pcretest, an escape such as \x{de} in the data was always generating
577        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
578        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
579        truncation.
581    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
583    7.  Added two (int) casts to pcregrep when printing the difference of two
584        pointers, in case they are 64-bit values.
586    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
587        test 2 if it fails.
589    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
590        and a #define of that name to empty if it is not externally set. This is to
591        allow users of MSVC to set it if necessary.
593    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
594        the convenience functions in the pcre_get.c source file.
596    11. An option change at the start of a pattern that had top-level alternatives
597        could cause overwriting and/or a crash. This command provoked a crash in
598        some environments:
600          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
602        This potential security problem was recorded as CVE-2008-2371.
604    12. For a pattern where the match had to start at the beginning or immediately
605        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
606        pcre_dfa_exec() could read past the end of the passed subject if there was
607        no match. To help with detecting such bugs (e.g. with valgrind), I modified
608        pcretest so that it places the subject at the end of its malloc-ed buffer.
610    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
611        exec() might read past the end of the data buffer in UTF-8 mode.
613    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
614        the data contained the byte 0x85 as part of a UTF-8 character within its
615        first line. This applied both to normal and DFA matching.
617    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
618        /^[^d]*?$/8 failed to match "abc".
620    16. Added a missing copyright notice to pcrecpp_internal.h.
622    17. Make it more clear in the documentation that values returned from
623        pcre_exec() in ovector are byte offsets, not character counts.
625    18. Tidied a few places to stop certain compilers from issuing warnings.
627    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
628        supplied by Stefan Weber. I made a further small update for 7.8 because
629        there is a change of source arrangements: the pcre_searchfuncs.c module is
630        replaced by pcre_ucd.c.
633    Version 7.7 07-May-08
634    ---------------------
636    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
637        a string to a long long, pretend we don't even have a long long." This is
638        done by checking for the strtoq, strtoll, and _strtoi64 functions.
640    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
641        pre-7.6 versions, which defined a global no_arg variable instead of putting
642        it in the RE class. (See also #8 below.)
644    3.  Remove a line of dead code, identified by coverity and reported by Nuno
645        Lopes.
647    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
649        (1) The include/exclude patterns were being applied to the whole pathnames
650            of files, instead of just to the final components.
652        (2) If there was more than one level of directory, the subdirectories were
653            skipped unless they satisfied the include/exclude conditions. This is
654            inconsistent with GNU grep (and could even be seen as contrary to the
655            pcregrep specification - which I improved to make it absolutely clear).
656            The action now is always to scan all levels of directory, and just
657            apply the include/exclude patterns to regular files.
659    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
660        --exclude_dir in the tests to avoid scanning .svn directories.
662    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
663        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
664        doesn't support NULs in patterns.
666    7.  Added some missing "const"s to declarations of static tables in
667        pcre_compile.c and pcre_dfa_exec.c.
669    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
670        caused by fix #2  above. (Subsequently also a second patch to fix the
671        first patch. And a third patch - this was a messy problem.)
673    9.  Applied Craig's patch to remove the use of push_back().
675    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
676        matching function regexec().
678    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
679        which, however, unlike Perl's \g{...}, are subroutine calls, not back
680        references. PCRE supports relative numbers with this syntax (I don't think
681        Oniguruma does).
683    12. Previously, a group with a zero repeat such as (...){0} was completely
684        omitted from the compiled regex. However, this means that if the group
685        was called as a subroutine from elsewhere in the pattern, things went wrong
686        (an internal error was given). Such groups are now left in the compiled
687        pattern, with a new opcode that causes them to be skipped at execution
688        time.
690    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
691        to the way PCRE behaves:
693        (a) A lone ] character is dis-allowed (Perl treats it as data).
695        (b) A back reference to an unmatched subpattern matches an empty string
696            (Perl fails the current match path).
698        (c) A data ] in a character class must be notated as \] because if the
699            first data character in a class is ], it defines an empty class. (In
700            Perl it is not possible to have an empty class.) The empty class []
701            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
702            The negative empty class [^] matches any one character, independently
703            of the DOTALL setting.
705    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
706        non-existent subpattern following a character class starting with ']' and
707        containing () gave an internal compiling error instead of "reference to
708        non-existent subpattern". Fortunately, when the pattern did exist, the
709        compiled code was correct. (When scanning forwards to check for the
710        existencd of the subpattern, it was treating the data ']' as terminating
711        the class, so got the count wrong. When actually compiling, the reference
712        was subsequently set up correctly.)
714    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
715        it was being rejected as not supported by pcre_dfa_exec(), even though
716        other assertions are supported. I have made pcre_dfa_exec() support
717        (*FAIL).
719    16. The implementation of 13c above involved the invention of a new opcode,
720        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
721        cannot be changed at match time, I realized I could make a small
722        improvement to matching performance by compiling OP_ALLANY instead of
723        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
724        on the OP_ANY path.
726    17. Compiling pcretest on Windows with readline support failed without the
727        following two fixes: (1) Make the unistd.h include conditional on
728        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
730    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
731        ncurses library to be included for pcretest when ReadLine support is
732        requested, but also to allow for it to be overridden. This patch came from
733        Daniel Bergström.
735    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
736        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
737        any errors with the current Unicode tables. Thanks to Peter Kankowski for
738        spotting this.
741    Version 7.6 28-Jan-08
742    ---------------------
744    1.  A character class containing a very large number of characters with
745        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
746        overflow.
748    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
749        HAVE_LONG_LONG is not defined.
751    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
752        bring them up to date and include new features. This patch includes:
754        - Fixed PH's badly added libz and libbz2 support.
755        - Fixed a problem with static linking.
756        - Added pcredemo. [But later removed - see 7 below.]
757        - Fixed dftables problem and added an option.
758        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
759            HAVE_LONG_LONG.
760        - Added readline support for pcretest.
761        - Added an listing of the option settings after cmake has run.
763    4.  A user submitted a patch to Makefile that makes it easy to create
764        "pcre.dll" under mingw when using Configure/Make. I added stuff to
765        Makefile.am that cause it to include this special target, without
766        affecting anything else. Note that the same mingw target plus all
767        the other distribution libraries and programs are now supported
768        when configuring with CMake (see 6 below) instead of with
769        Configure/Make.
771    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
772        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
773        exported in the Windows port". It has not yet been confirmed that the patch
774        solves the problem, but it does no harm.
776    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
777        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
778        with CMake, and also correct the comment about stack recursion.
780    7.  Remove the automatic building of pcredemo from the ./configure system and
781        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
782        of a program that users should build themselves after PCRE is installed, so
783        building it automatically is not really right. What is more, it gave
784        trouble in some build environments.
786    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
789    Version 7.5 10-Jan-08
790    ---------------------
792    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
793        values in parens when parsing an RE using the C++ wrapper."
795    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
796        Characters greater than 255 were excluded from the class instead of being
797        included.
799    3.  The same bug as (2) above applied to negated POSIX classes such as
800        [:^space:].
802    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
803        defined or documented. It seems to have been a typo for PCRE_STATIC, so
804        I have changed it.
806    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
807        first named subpattern) and a construct such as (?&a) would reference the
808        first named subpattern whose name started with "a" (in other words, the
809        length check was missing). Both these problems are fixed. "Subpattern name
810        expected" is now given for (?&) (a zero-length name), and this patch also
811        makes it give the same error for \k'' (previously it complained that that
812        was a reference to a non-existent subpattern).
814    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
815        this is right because (?- can be followed by option settings as well as by
816        digits. I have, however, made the messages clearer.
818    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
819        than the number used in the conditional) now cause a compile-time error.
820        This is actually not compatible with Perl, which accepts such patterns, but
821        treats the conditional as always being FALSE (as PCRE used to), but it
822        seems to me that giving a diagnostic is better.
824    8.  Change "alphameric" to the more common word "alphanumeric" in comments
825        and messages.
827    9.  Fix two occurrences of "backslash" in comments that should have been
828        "backspace".
830    10. Remove two redundant lines of code that can never be obeyed (their function
831        was moved elsewhere).
833    11. The program that makes PCRE's Unicode character property table had a bug
834        which caused it to generate incorrect table entries for sequences of
835        characters that have the same character type, but are in different scripts.
836        It amalgamated them into a single range, with the script of the first of
837        them. In other words, some characters were in the wrong script. There were
838        thirteen such cases, affecting characters in the following ranges:
840          U+002b0 - U+002c1
841          U+0060c - U+0060d
842          U+0061e - U+00612
843          U+0064b - U+0065e
844          U+0074d - U+0076d
845          U+01800 - U+01805
846          U+01d00 - U+01d77
847          U+01d9b - U+01dbf
848          U+0200b - U+0200f
849          U+030fc - U+030fe
850          U+03260 - U+0327f
851          U+0fb46 - U+0fbb1
852          U+10450 - U+1049d
854    12. The -o option (show only the matching part of a line) for pcregrep was not
855        compatible with GNU grep in that, if there was more than one match in a
856        line, it showed only the first of them. It now behaves in the same way as
857        GNU grep.
859    13. If the -o and -v options were combined for pcregrep, it printed a blank
860        line for every non-matching line. GNU grep prints nothing, and pcregrep now
861        does the same. The return code can be used to tell if there were any
862        non-matching lines.
864    14. Added --file-offsets and --line-offsets to pcregrep.
866    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
867        infinitely looping recursion. The bug was that positive lookaheads were not
868        being skipped when checking for a possible empty match (negative lookaheads
869        and both kinds of lookbehind were skipped).
871    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
872        inclusion of <windows.h> to before rather than after the definition of
873        INVALID_FILE_ATTRIBUTES (patch from David Byron).
875    17. Specifying a possessive quantifier with a specific limit for a Unicode
876        character property caused pcre_compile() to compile bad code, which led at
877        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
878        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
879        caused the error; without that there was no problem.
881    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
883    19. Added --enable-pcretest-libreadline.
885    20. In pcrecpp.cc, the variable 'count' was incremented twice in
886        RE::GlobalReplace(). As a result, the number of replacements returned was
887        double what it should be. I removed one of the increments, but Craig sent a
888        later patch that removed the other one (the right fix) and added unit tests
889        that check the return values (which was not done before).
891    21. Several CMake things:
893        (1) Arranged that, when cmake is used on Unix, the libraries end up with
894            the names libpcre and libpcreposix, not just pcre and pcreposix.
896        (2) The above change means that pcretest and pcregrep are now correctly
897            linked with the newly-built libraries, not previously installed ones.
901    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
902        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
903        UTF-8 newline character). The key issue is that the pattern starts .*;
904        this means that the match must be either at the beginning, or after a
905        newline. The bug was in the code for advancing after a failed match and
906        checking that the new position followed a newline. It was not taking
907        account of UTF-8 characters correctly.
909    23. PCRE was behaving differently from Perl in the way it recognized POSIX
910        character classes. PCRE was not treating the sequence [:...:] as a
911        character class unless the ... were all letters. Perl, however, seems to
912        allow any characters between [: and :], though of course it rejects as
913        unknown any "names" that contain non-letters, because all the known class
914        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
915        for example, whereas PCRE did not - it did not recognize a POSIX character
916        class. This seemed a bit dangerous, so the code has been changed to be
917        closer to Perl. The behaviour is not identical to Perl, because PCRE will
918        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
919        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
920        Perl does, and where it didn't before.
922    24. Rewrite so as to remove the single use of %n from pcregrep because in some
923        Windows environments %n is disabled by default.
926    Version 7.4 21-Sep-07
927    ---------------------
929    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
930        means that a class such as [\s] counted as "explicit reference to CR or
931        LF". That isn't really right - the whole point of the change was to try to
932        help when there was an actual mention of one of the two characters. So now
933        the change happens only if \r or \n (or a literal CR or LF) character is
934        encountered.
936    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
937        of both had grown to the point where there were only 3 bits left.
938        Fortunately, there was spare space in the data structure, and so I have
939        moved the internal flags into a new 16-bit field to free up more option
940        bits.
942    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
943        but did not set the internal JCHANGED flag - either of these is enough to
944        control the way the "get" function works - but the PCRE_INFO_JCHANGED
945        facility is supposed to tell if (?J) was ever used, so now (?J) at the
946        start sets both bits.
948    4.  Added options (at build time, compile time, exec time) to change \R from
949        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
951    5.  doc/pcresyntax.html was missing from the distribution.
953    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
954        compatibility, even though it is no longer used.
956    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
957        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
958        windows.h file is present (where different names are used). [This was
959        reversed later after testing - see 16 below.]
961    8.  Changed all #include <config.h> to #include "config.h". There were also
962        some further <pcre.h> cases that I changed to "pcre.h".
964    9.  When pcregrep was used with the --colour option, it missed the line ending
965        sequence off the lines that it output.
967    10. It was pointed out to me that arrays of string pointers cause lots of
968        relocations when a shared library is dynamically loaded. A technique of
969        using a single long string with a table of offsets can drastically reduce
970        these. I have refactored PCRE in four places to do this. The result is
971        dramatic:
973          Originally:                          290
974          After changing UCP table:            187
975          After changing error message table:   43
976          After changing table of "verbs"       36
977          After changing table of Posix names   22
979        Thanks to the folks working on Gregex for glib for this insight.
981    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
982        unicode-properties was also set.
984    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
986    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
987        checked only for CRLF.
989    14. Added casts to pcretest.c to avoid compiler warnings.
991    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
993    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
994        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
995        entirely. This removes changes made in 7 above.
997    17. The CMake files have been updated, and there is now more information about
998        building with CMake in the NON-UNIX-USE document.
1001    Version 7.3 28-Aug-07
1002    ---------------------
1004     1. In the rejigging of the build system that eventually resulted in 7.1, the
1005        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1006        brackets there is not right, since it causes compilers to look for an
1007        installed pcre.h, not the version that is in the source that is being
1008        compiled (which of course may be different). I have changed it back to:
1010          #include "pcre.h"
1012        I have a vague recollection that the change was concerned with compiling in
1013        different directories, but in the new build system, that is taken care of
1014        by the VPATH setting the Makefile.
1016     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1017        when the subject happened to end in the byte 0x85 (e.g. if the last
1018        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1019        characters but of course it shouldn't be taken as a newline when it is part
1020        of another character. The bug was that, for an unlimited repeat of . in
1021        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1022        characters when looking for a newline.
1024     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1026     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1027        in debug output.
1029     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1030        long printing in the pcrecpp unittest when running under MinGW.
1032     6. ESC_K was left out of the EBCDIC table.
1034     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1035        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1036        limit also applies to "virtual nesting" when a pattern is recursive, and in
1037        this case 1000 isn't so big. I have been able to remove this limit at the
1038        expense of backing off one optimization in certain circumstances. Normally,
1039        when pcre_exec() would call its internal match() function recursively and
1040        immediately return the result unconditionally, it uses a "tail recursion"
1041        feature to save stack. However, when a subpattern that can match an empty
1042        string has an unlimited repetition quantifier, it no longer makes this
1043        optimization. That gives it a stack frame in which to save the data for
1044        checking that an empty string has been matched. Previously this was taken
1045        from the 1000-entry workspace that had been reserved. So now there is no
1046        explicit limit, but more stack is used.
1048     8. Applied Daniel's patches to solve problems with the import/export magic
1049        syntax that is required for Windows, and which was going wrong for the
1050        pcreposix and pcrecpp parts of the library. These were overlooked when this
1051        problem was solved for the main library.
1053     9. There were some crude static tests to avoid integer overflow when computing
1054        the size of patterns that contain repeated groups with explicit upper
1055        limits. As the maximum quantifier is 65535, the maximum group length was
1056        set at 30,000 so that the product of these two numbers did not overflow a
1057        32-bit integer. However, it turns out that people want to use groups that
1058        are longer than 30,000 bytes (though not repeat them that many times).
1059        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1060        made it possible to implement the integer overflow checks in a much more
1061        dynamic way, which I have now done. The artificial limitation on group
1062        length has been removed - we now have only the limit on the total length of
1063        the compiled pattern, which depends on the LINK_SIZE setting.
1065    10. Fixed a bug in the documentation for get/copy named substring when
1066        duplicate names are permitted. If none of the named substrings are set, the
1067        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1068        empty string.
1070    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1071        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1072        because the ] is interpreted as the first data character and the
1073        terminating ] is not found. PCRE has been made compatible with Perl in this
1074        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1075        cause memory overwriting.
1077    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1078        string has been matched (to stop an infinite loop). It was not recognizing
1079        a conditional subpattern that could match an empty string if that
1080        subpattern was within another subpattern. For example, it looped when
1081        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1082        condition was not nested. This bug has been fixed.
1084    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1085        past the start of the subject in the presence of bytes with the top bit
1086        set, for example "\x8aBCD".
1088    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1089        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1091    14. Optimized (?!) to (*FAIL).
1093    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1094        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1095        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1096        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1097        does: it's just the validity check that is more restrictive.
1099    16. Inserted checks for integer overflows during escape sequence (backslash)
1100        processing, and also fixed erroneous offset values for syntax errors during
1101        backslash processing.
1103    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1104        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1106    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1107        caused an overrun.
1109    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1110        something other than just ASCII characters) inside a group that had an
1111        unlimited repeat caused a loop at compile time (while checking to see
1112        whether the group could match an empty string).
1114    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1115        [\P{Any}] did so. (Error in the code for printing property names.)
1117    21. An orphan \E inside a character class could cause a crash.
1119    22. A repeated capturing bracket such as (A)? could cause a wild memory
1120        reference during compilation.
1122    23. There are several functions in pcre_compile() that scan along a compiled
1123        expression for various reasons (e.g. to see if it's fixed length for look
1124        behind). There were bugs in these functions when a repeated \p or \P was
1125        present in the pattern. These operators have additional parameters compared
1126        with \d, etc, and these were not being taken into account when moving along
1127        the compiled data. Specifically:
1129        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1130            length.
1132        (b) An item such as \pL+ within a repeated group could cause crashes or
1133            loops.
1135        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1136            "reference to non-existent subpattern" error.
1138        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1140    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1141        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1143    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1145    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1146        character were causing crashes (broken optimization).
1148    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1149        \p or \P) caused a compile-time loop.
1151    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1152        break. For example, the unstudied pattern [\r\n]A does not match the string
1153        "\r\nA" because change 7.0/46 below moves the current point on by two
1154        characters after failing to match at the start. However, the pattern \nA
1155        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1156        the same is true. There doesn't seem any very clean way out of this, but
1157        what I have chosen to do makes the common cases work: PCRE now takes note
1158        of whether there can be an explicit match for \r or \n anywhere in the
1159        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1160        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1161        pattern has explicit CR or LF references.
1163    29. Added (*CR) etc for changing newline setting at start of pattern.
1166    Version 7.2 19-Jun-07
1167    ---------------------
1169     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1170        which is apparently normally available under Windows.
1172     2. Re-jig the pcregrep tests with different newline settings in an attempt
1173        to make them independent of the local environment's newline setting.
1175     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1177     4. Some of the "internals" tests were previously cut out when the link size
1178        was not 2, because the output contained actual offsets. The recent new
1179        "Z" feature of pcretest means that these can be cut out, making the tests
1180        usable with all link sizes.
1182     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1183        stack recursion. This gives a massive performance boost under BSD, but just
1184        a small improvement under Linux. However, it saves one field in the frame
1185        in all cases.
1187     6. Added more features from the forthcoming Perl 5.10:
1189        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1190            recursion call. It refers to the nth most recently opened parentheses.
1192        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1193            to be opened parentheses.
1195        (c) Conditions that refer to capturing parentheses can be specified
1196            relatively, for example, (?(-2)... or (?(+3)...
1198        (d) \K resets the start of the current match so that everything before
1199            is not part of it.
1201        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1203        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1204            reference syntax.
1206        (g) (?| introduces a group in which the numbering of parentheses in each
1207            alternative starts with the same number.
1209        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1211     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1214     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1215        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1216        for detecting groups that can match an empty string.
1218     9. A pattern with a very large number of alternatives (more than several
1219        hundred) was running out of internal workspace during the pre-compile
1220        phase, where pcre_compile() figures out how much memory will be needed. A
1221        bit of new cunning has reduced the workspace needed for groups with
1222        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1223        workspace instead of running out of the 4096 that are available.
1225    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1227    11. Applied patch from Google to remove an optimization that didn't quite work.
1228        The report of the bug said:
1230          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1231          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1232          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1234    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1235        it matched the wrong number of bytes.
1238    Version 7.1 24-Apr-07
1239    ---------------------
1241     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1242        that is more "standard", making use of automake and other Autotools. There
1243        is some re-arrangement of the files and adjustment of comments consequent
1244        on this.
1246     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1247        for recursive directory scanning broke on some systems because the files
1248        are not scanned in any specific order and on different systems the order
1249        was different. A call to "sort" has been inserted into RunGrepTest for the
1250        approprate test as a short-term fix. In the longer term there may be an
1251        alternative.
1253     3. I had an email from Eric Raymond about problems translating some of PCRE's
1254        man pages to HTML (despite the fact that I distribute HTML pages, some
1255        people do their own conversions for various reasons). The problems
1256        concerned the use of low-level troff macros .br and .in. I have therefore
1257        removed all such uses from the man pages (some were redundant, some could
1258        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1259        HTML has been updated to handle .nf/.fi and to complain if it encounters
1260        .br or .in.
1262     4. Updated comments in configure.ac that get placed in config.h.in and also
1263        arranged for config.h to be included in the distribution, with the name
1264        config.h.generic, for the benefit of those who have to compile without
1265        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1267     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1268        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1269        makevp.bat for the current PCRE, using the additional files
1270        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1272     6. A Windows user reported a minor discrepancy with test 2, which turned out
1273        to be caused by a trailing space on an input line that had got lost in his
1274        copy. The trailing space was an accident, so I've just removed it.
1276     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1277        that is needed.
1279     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1280        as "const" (a) because they are and (b) because it helps the PHP
1281        maintainers who have recently made a script to detect big data structures
1282        in the php code that should be moved to the .rodata section. I remembered
1283        to update Builducptable as well, so it won't revert if ucptable.h is ever
1284        re-created.
1286     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1287        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1288        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1289        support is not required. This saves 1.5-2K of code, which is important in
1290        some applications.
1292        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1293        so as not to refer to the tables, even though these functions will never be
1294        called when UTF-8 support is disabled. Otherwise there are problems with a
1295        shared library.
1297    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1299        (a) It was defining its arguments as char * instead of void *.
1301        (b) It was assuming that all moves were upwards in memory; this was true
1302            a long time ago when I wrote it, but is no longer the case.
1304        The emulated memove() is provided for those environments that have neither
1305        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1306        is clearly not the case, as these two bugs were recently reported.
1308    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1309        and Detrail to create the HTML documentation, the .txt form of the man
1310        pages, and it removes trailing spaces from listed files. It also creates
1311        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1312        case, it wraps all the #defines with #ifndefs. This script should be run
1313        before "make dist".
1315    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1316        with Unicode property support.
1318        (a) For a maximizing quantifier, if the two different cases of the
1319            character were of different lengths in their UTF-8 codings (there are
1320            some cases like this - I found 11), and the matching function had to
1321            back up over a mixture of the two cases, it incorrectly assumed they
1322            were both the same length.
1324        (b) When PCRE was configured to use the heap rather than the stack for
1325            recursion during matching, it was not correctly preserving the data for
1326            the other case of a UTF-8 character when checking ahead for a match
1327            while processing a minimizing repeat. If the check also involved
1328            matching a wide character, but failed, corruption could cause an
1329            erroneous result when trying to check for a repeat of the original
1330            character.
1332    13. Some tidying changes to the testing mechanism:
1334        (a) The RunTest script now detects the internal link size and whether there
1335            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1336            values substituted by "configure". (The RunGrepTest script already did
1337            this for UTF-8.) The configure.ac script no longer substitutes the
1338            relevant variables.
1340        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1341            with length and offset values. This means that the output is different
1342            for different internal link sizes. Test 2 is skipped for link sizes
1343            other than 2 because of this, bypassing the problem. Unfortunately,
1344            there was also a test in test 3 (the locale tests) that used /B and
1345            failed for link sizes other than 2. Rather than cut the whole test out,
1346            I have added a new /Z option to pcretest that replaces the length and
1347            offset values with spaces. This is now used to make test 3 independent
1348            of link size. (Test 2 will be tidied up later.)
1350    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1351        segmentation fault instead of returning the appropriate error message.
1353    15. In multiline mode when the newline sequence was set to "any", the pattern
1354        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1355        This doesn't seem right; it now treats the CRLF combination as the line
1356        ending, and so does not match in that case. It's only a pattern such as ^$
1357        that would hit this one: something like ^ABC$ would have failed after \r
1358        and then tried again after \r\n.
1360    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1361        in an attempt to make files that differ only in their line terminators
1362        compare equal. This works on Linux.
1364    17. Under certain error circumstances pcregrep might try to free random memory
1365        as it exited. This is now fixed, thanks to valgrind.
1367    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1368        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1369        was because its rules for how to advance for /g after matching an empty
1370        string at the end of a line did not allow for this case. They now check for
1371        it specially.
1373    20. pcretest is supposed to handle patterns and data of any length, by
1374        extending its buffers when necessary. It was getting this wrong when the
1375        buffer for a data line had to be extended.
1377    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1378        CRLF as a newline sequence.
1380    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1381        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1382        I have nevertheless tidied it up.
1384    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1386    24. Added a man page for pcre-config.
1389    Version 7.0 19-Dec-06
1390    ---------------------
1392     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1393        moving to gcc 4.1.1.
1395     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1396        sys/time.h, which is documented as needed for this function. It doesn't
1397        seem to matter on Linux, but it showed up on some releases of OS X.
1399     3. It seems that there are systems where bytes whose values are greater than
1400        127 match isprint() in the "C" locale. The "C" locale should be the
1401        default when a C program starts up. In most systems, only ASCII printing
1402        characters match isprint(). This difference caused the output from pcretest
1403        to vary, making some of the tests fail. I have changed pcretest so that:
1405        (a) When it is outputting text in the compiled version of a pattern, bytes
1406            other than 32-126 are always shown as hex escapes.
1408        (b) When it is outputting text that is a matched part of a subject string,
1409            it does the same, unless a different locale has been set for the match
1410            (using the /L modifier). In this case, it uses isprint() to decide.
1412     4. Fixed a major bug that caused incorrect computation of the amount of memory
1413        required for a compiled pattern when options that changed within the
1414        pattern affected the logic of the preliminary scan that determines the
1415        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1416        that the computed length was too small. The symptoms of this bug were
1417        either the PCRE error "internal error: code overflow" from pcre_compile(),
1418        or a glibc crash with a message such as "pcretest: free(): invalid next
1419        size (fast)". Examples of patterns that provoked this bug (shown in
1420        pcretest format) are:
1422          /(?-x: )/x
1423          /(?x)(?-x: \s*#\s*)/
1424          /((?i)[\x{c0}])/8
1425          /(?i:[\x{c0}])/8
1427        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1428        is now done differently.
1430     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1431        wrapper classes; (b) implement a new function in the C++ scanner that is
1432        more efficient than the old way of doing things because it avoids levels of
1433        recursion in the regex matching; (c) add a paragraph to the documentation
1434        for the FullMatch() function.
1436     6. The escape sequence \n was being treated as whatever was defined as
1437        "newline". Not only was this contrary to the documentation, which states
1438        that \n is character 10 (hex 0A), but it also went horribly wrong when
1439        "newline" was defined as CRLF. This has been fixed.
1441     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1442        was being set to -1 for the "end of line" case (supposedly a value that no
1443        character can have). Though this value is never used (the check for end of
1444        line is "zero bytes in current character"), it caused compiler complaints.
1445        I've changed it to 0xffffffff.
1447     8. In pcre_version.c, the version string was being built by a sequence of
1448        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1449        string (as it is for production releases) called a macro with an empty
1450        argument. The C standard says the result of this is undefined. The gcc
1451        compiler treats it as an empty string (which was what was wanted) but it is
1452        reported that Visual C gives an error. The source has been hacked around to
1453        avoid this problem.
1455     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1456        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1457        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1458        of them did).
1460    10. Originally, pcretest opened its input and output without "b"; then I was
1461        told that "b" was needed in some environments, so it was added for release
1462        5.0 to both the input and output. (It makes no difference on Unix-like
1463        systems.) Later I was told that it is wrong for the input on Windows. I've
1464        now abstracted the modes into two macros, to make it easier to fiddle with
1465        them, and removed "b" from the input mode under Windows.
1467    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1469    12. Added -help and --help to pcretest as an official way of being reminded
1470        of the options.
1472    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1473        and pcrecpp.cc because they annoy compilers at high warning levels.
1475    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1477    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1478        scripts are not C programs :-) and which was not noticed because it works
1479        on Linux.
1481    16. pcretest is supposed to handle any length of pattern and data line (as one
1482        line or as a continued sequence of lines) by extending its input buffer if
1483        necessary. This feature was broken for very long pattern lines, leading to
1484        a string of junk being passed to pcre_compile() if the pattern was longer
1485        than about 50K.
1487    17. I have done a major re-factoring of the way pcre_compile() computes the
1488        amount of memory needed for a compiled pattern. Previously, there was code
1489        that made a preliminary scan of the pattern in order to do this. That was
1490        OK when PCRE was new, but as the facilities have expanded, it has become
1491        harder and harder to keep it in step with the real compile phase, and there
1492        have been a number of bugs (see for example, 4 above). I have now found a
1493        cunning way of running the real compile function in a "fake" mode that
1494        enables it to compute how much memory it would need, while actually only
1495        ever using a few hundred bytes of working memory and without too many
1496        tests of the mode. This should make future maintenance and development
1497        easier. A side effect of this work is that the limit of 200 on the nesting
1498        depth of parentheses has been removed (though this was never a serious
1499        limitation, I suspect). However, there is a downside: pcre_compile() now
1500        runs more slowly than before (30% or more, depending on the pattern). I
1501        hope this isn't a big issue. There is no effect on runtime performance.
1503    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1504        newline (only possible for the last line of a file) and it was a
1505        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1507    19. Added additional timing features to pcretest. (1) The -tm option now times
1508        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1509        separate command line item, by a number that specifies the number of
1510        repeats to use when timing. The default is 50000; this gives better
1511        precision, but takes uncomfortably long for very large patterns.
1513    20. Extended pcre_study() to be more clever in cases where a branch of a
1514        subpattern has no definite first character. For example, (a*|b*)[cd] would
1515        previously give no result from pcre_study(). Now it recognizes that the
1516        first character must be a, b, c, or d.
1518    21. There was an incorrect error "recursive call could loop indefinitely" if
1519        a subpattern (or the entire pattern) that was being tested for matching an
1520        empty string contained only one non-empty item after a nested subpattern.
1521        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1522        incorrectly, because the \d was being skipped in the check.
1524    22. The pcretest program now has a new pattern option /B and a command line
1525        option -b, which is equivalent to adding /B to every pattern. This causes
1526        it to show the compiled bytecode, without the additional information that
1527        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1528        is the same as /B/I).
1530    23. A new optimization is now able automatically to treat some sequences such
1531        as a*b as a*+b. More specifically, if something simple (such as a character
1532        or a simple class like \d) has an unlimited quantifier, and is followed by
1533        something that cannot possibly match the quantified thing, the quantifier
1534        is automatically "possessified".
1536    24. A recursive reference to a subpattern whose number was greater than 39
1537        went wrong under certain circumstances in UTF-8 mode. This bug could also
1538        have affected the operation of pcre_study().
1540    25. Realized that a little bit of performance could be had by replacing
1541        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1543    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1545    27. Possessive quantifiers such as a++ were previously implemented by turning
1546        them into atomic groups such as ($>a+). Now they have their own opcodes,
1547        which improves performance. This includes the automatically created ones
1548        from 23 above.
1550    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1551        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1552        the first matched character to be a colon. This applied both to named and
1553        numbered groups.
1555    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1557    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1558        building PCRE on Windows easier, so I have included it in the distribution.
1560    31. There is now a check in pcretest against a ridiculously large number being
1561        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1562        loop, the loop is abandoned.
1564    32. Forward references to subpatterns in conditions such as (?(2)...) where
1565        subpattern 2 is defined later cause pcre_compile() to search forwards in
1566        the pattern for the relevant set of parentheses. This search went wrong
1567        when there were unescaped parentheses in a character class, parentheses
1568        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1570    33. "Subroutine" calls and backreferences were previously restricted to
1571        referencing subpatterns earlier in the regex. This restriction has now
1572        been removed.
1574    34. Added a number of extra features that are going to be in Perl 5.10. On the
1575        whole, these are just syntactic alternatives for features that PCRE had
1576        previously implemented using the Python syntax or my own invention. The
1577        other formats are all retained for compatibility.
1579        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1580            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1581            also .NET compatible.
1583        (b) A recursion or subroutine call to a named group can now be defined as
1584            (?&name) as well as (?P>name).
1586        (c) A backreference to a named group can now be defined as \k<name> or
1587            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1588            5.10, are also .NET compatible.
1590        (d) A conditional reference to a named group can now use the syntax
1591            (?(<name>) or (?('name') as well as (?(name).
1593        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1594            groups (named and numbered) that are never evaluated inline, but can be
1595            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1596            is always false. There may be only one alternative in such a group.
1598        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1599            as the simple (?(R). The condition is true only if the most recent
1600            recursion is that of the given number or name. It does not search out
1601            through the entire recursion stack.
1603        (g) The escape \gN or \g{N} has been added, where N is a positive or
1604            negative number, specifying an absolute or relative reference.
1606    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1607        some "unreachable code" warnings.
1609    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1610        things, this adds five new scripts.
1612    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1613        There were also incompatibilities regarding the handling of \Q..\E inside
1614        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1615        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1617    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1618        matches an empty string, and forcibly breaks the loop. There were bugs in
1619        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1620        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1621        separate and independent bugs (that affected different cases) have been
1622        fixed.
1624    39. Refactored the code to abolish the use of different opcodes for small
1625        capturing bracket numbers. This is a tidy that I avoided doing when I
1626        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1627        The new approach is not only tidier, it makes it possible to reduce the
1628        memory needed to fix the previous bug (38).
1630    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1631        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1632        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1633        mode.
1635    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1636        report.
1638    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1639        copy construction and assignment in the C++ wrapper.
1641    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1642        couple of bugs that could have given wrong results in the "--newline=crlf"
1643        case.
1645    44. Added a number of casts and did some reorganization of signed/unsigned int
1646        variables following suggestions from Dair Grant. Also renamed the variable
1647        "this" as "item" because it is a C++ keyword.
1649    45. Arranged for dftables to add
1651          #include "pcre_internal.h"
1653        to pcre_chartables.c because without it, gcc 4.x may remove the array
1654        definition from the final binary if PCRE is built into a static library and
1655        dead code stripping is activated.
1657    46. For an unanchored pattern, if a match attempt fails at the start of a
1658        newline sequence, and the newline setting is CRLF or ANY, and the next two
1659        characters are CRLF, advance by two characters instead of one.
1662    Version 6.7 04-Jul-06
1663    ---------------------
1665     1. In order to handle tests when input lines are enormously long, pcretest has
1666        been re-factored so that it automatically extends its buffers when
1667        necessary. The code is crude, but this _is_ just a test program. The
1668        default size has been increased from 32K to 50K.
1670     2. The code in pcre_study() was using the value of the re argument before
1671        testing it for NULL. (Of course, in any sensible call of the function, it
1672        won't be NULL.)
1674     3. The memmove() emulation function in pcre_internal.h, which is used on
1675        systems that lack both memmove() and bcopy() - that is, hardly ever -
1676        was missing a "static" storage class specifier.
1678     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1679        containing an extended class (one that cannot be represented by a bitmap
1680        because it contains high-valued characters or Unicode property items, e.g.
1681        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1682        pattern, but PCRE should not loop if you do not (it no longer does).
1683        [Detail: two cases were found: (a) a repeated subpattern containing an
1684        extended class; (b) a recursive reference to a subpattern that followed a
1685        previous extended class. It wasn't skipping over the extended class
1686        correctly when UTF-8 mode was not set.]
1688     5. A negated single-character class was not being recognized as fixed-length
1689        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1690        compile error "lookbehind assertion is not fixed length".
1692     6. The RunPerlTest auxiliary script was showing an unexpected difference
1693        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1694        write a Perl script that can interpret lines of an input file either as
1695        byte characters or as UTF-8, which is what "perltest" was being required to
1696        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1697        can't do is switch easily at run time between having the "use utf8;" pragma
1698        or not. In the end, I fudged it by using the RunPerlTest script to insert
1699        "use utf8;" explicitly for the UTF-8 tests.
1701     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1702        the end of the subject string, contrary to the documentation and to what
1703        Perl does. This was true of both matching functions. Now it matches only at
1704        the start of the subject and immediately after *internal* newlines.
1706     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1707        a pointer to an int instead of a pointer to an unsigned long int. This
1708        caused problems on 64-bit systems.
1710     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1711        instance of the 'standard' template library not being so standard".
1713    10. There was no check on the number of named subpatterns nor the maximum
1714        length of a subpattern name. The product of these values is used to compute
1715        the size of the memory block for a compiled pattern. By supplying a very
1716        long subpattern name and a large number of named subpatterns, the size
1717        computation could be caused to overflow. This is now prevented by limiting
1718        the length of names to 32 characters, and the number of named subpatterns
1719        to 10,000.
1721    11. Subpatterns that are repeated with specific counts have to be replicated in
1722        the compiled pattern. The size of memory for this was computed from the
1723        length of the subpattern and the repeat count. The latter is limited to
1724        65535, but there was no limit on the former, meaning that integer overflow
1725        could in principle occur. The compiled length of a repeated subpattern is
1726        now limited to 30,000 bytes in order to prevent this.
1728    12. Added the optional facility to have named substrings with the same name.
1730    13. Added the ability to use a named substring as a condition, using the
1731        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1732        are numbers (not recommended). Forward references are permitted.
1734    14. Added forward references in named backreferences (if you see what I mean).
1736    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1737        pattern could run off the end of the subject. For example, the pattern
1738        "(?s)(.{1,5})"8 did this with the subject "ab".
1740    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1741        PCRE_CASELESS was set when matching characters that were quantified with ?
1742        or *.
1744    17. A character class other than a single negated character that had a minimum
1745        but no maximum quantifier - for example [ab]{6,} - was not handled
1746        correctly by pce_dfa_exec(). It would match only one character.
1748    18. A valid (though odd) pattern that looked like a POSIX character
1749        class but used an invalid character after [ (for example [[,abc,]]) caused
1750        pcre_compile() to give the error "Failed: internal error: code overflow" or
1751        in some cases to crash with a glibc free() error. This could even happen if
1752        the pattern terminated after [[ but there just happened to be a sequence of
1753        letters, a binary zero, and a closing ] in the memory that followed.
1755    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1756        over the years. Originally (before any Unicode support), just the bottom 8
1757        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1758        output from "man perlunicode" includes this:
1760          The regular expression compiler produces polymorphic opcodes.  That
1761          is, the pattern adapts to the data and automatically switches to
1762          the Unicode character scheme when presented with Unicode data--or
1763          instead uses a traditional byte scheme when presented with byte
1764          data.
1766        Sadly, a wide octal escape does not cause a switch, and in a string with
1767        no other multibyte characters, these octal escapes are treated as before.
1768        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1769        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1770        Unicode string.
1772        I have not perpetrated such confusion in PCRE. Up till now, it took just
1773        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1774        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1775        translate to the appropriate multibyte character.
1777    29. Applied some refactoring to reduce the number of warnings from Microsoft
1778        and Borland compilers. This has included removing the fudge introduced
1779        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1780        a warning about an unused variable.
1782    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1783        characters since release 4.0, because Perl (from release 5.004) does not.
1784        [Or at least, is documented not to: some releases seem to be in conflict
1785        with the documentation.] However, when a pattern was studied with
1786        pcre_study() and all its branches started with \s, PCRE still included VT
1787        as a possible starting character. Of course, this did no harm; it just
1788        caused an unnecessary match attempt.
1790    22. Removed a now-redundant internal flag bit that recorded the fact that case
1791        dependency changed within the pattern. This was once needed for "required
1792        byte" processing, but is no longer used. This recovers a now-scarce options
1793        bit. Also moved the least significant internal flag bit to the most-
1794        significant bit of the word, which was not previously used (hangover from
1795        the days when it was an int rather than a uint) to free up another bit for
1796        the future.
1798    23. Added support for CRLF line endings as well as CR and LF. As well as the
1799        default being selectable at build time, it can now be changed at runtime
1800        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1801        specify that it is scanning data with non-default line endings.
1803    24. Changed the definition of CXXLINK to make it agree with the definition of
1804        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1806    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1807        recursions. This makes a big different to stack usage for some patterns.
1809    26. If a subpattern containing a named recursion or subroutine reference such
1810        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1811        the space required for the compiled pattern went wrong and gave too small a
1812        value. Depending on the environment, this could lead to "Failed: internal
1813        error: code overflow at offset 49" or "glibc detected double free or
1814        corruption" errors.
1816    27. Applied patches from Google (a) to support the new newline modes and (b) to
1817        advance over multibyte UTF-8 characters in GlobalReplace.
1819    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1820        difference for some implementation of PCRE in some Windows version.
1822    29. Added some extra testing facilities to pcretest:
1824        \q<number>   in a data line sets the "match limit" value
1825        \Q<number>   in a data line sets the "match recursion limt" value
1826        -S <number>  sets the stack size, where <number> is in megabytes
1828        The -S option isn't available for Windows.
1831    Version 6.6 06-Feb-06
1832    ---------------------
1834     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1835        in pcreposix.h. I have copied the definition from pcre.h.
1837     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1838        because pcre.h is no longer a built file.
1840     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1841        not normally included in the compiled code.
1844    Version 6.5 01-Feb-06
1845    ---------------------
1847     1. When using the partial match feature with pcre_dfa_exec(), it was not
1848        anchoring the second and subsequent partial matches at the new starting
1849        point. This could lead to incorrect results. For example, with the pattern
1850        /1234/, partially matching against "123" and then "a4" gave a match.
1852     2. Changes to pcregrep:
1854        (a) All non-match returns from pcre_exec() were being treated as failures
1855            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1856            error message is output. Some extra information is given for the
1857            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1858            probably the only errors that are likely to be caused by users (by
1859            specifying a regex that has nested indefinite repeats, for instance).
1860            If there are more than 20 of these errors, pcregrep is abandoned.
1862        (b) A binary zero was treated as data while matching, but terminated the
1863            output line if it was written out. This has been fixed: binary zeroes
1864            are now no different to any other data bytes.
1866        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1867            used to set a locale for matching. The --locale=xxxx long option has
1868            been added (no short equivalent) to specify a locale explicitly on the
1869            pcregrep command, overriding the environment variables.
1871        (d) When -B was used with -n, some line numbers in the output were one less
1872            than they should have been.
1874        (e) Added the -o (--only-matching) option.
1876        (f) If -A or -C was used with -c (count only), some lines of context were
1877            accidentally printed for the final match.
1879        (g) Added the -H (--with-filename) option.
1881        (h) The combination of options -rh failed to suppress file names for files
1882            that were found from directory arguments.
1884        (i) Added the -D (--devices) and -d (--directories) options.
1886        (j) Added the -F (--fixed-strings) option.
1888        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1890        (l) Added the --colo(u)r option.
1892        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1893            is not present by default.
1895     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1896        items such as (?R) or (?1), when the recursion could match a number of
1897        alternatives. If it matched one of the alternatives, but subsequently,
1898        outside the recursion, there was a failure, the code tried to back up into
1899        the recursion. However, because of the way PCRE is implemented, this is not
1900        possible, and the result was an incorrect result from the match.
1902        In order to prevent this happening, the specification of recursion has
1903        been changed so that all such subpatterns are automatically treated as
1904        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1906     4. I had overlooked the fact that, in some locales, there are characters for
1907        which isalpha() is true but neither isupper() nor islower() are true. In
1908        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1909        and ordfeminine) are like this. This affected the treatment of \w and \W
1910        when they appeared in character classes, but not when they appeared outside
1911        a character class. The bit map for "word" characters is now created
1912        separately from the results of isalnum() instead of just taking it from the
1913        upper, lower, and digit maps. (Plus the underscore character, of course.)
1915     5. The above bug also affected the handling of POSIX character classes such as
1916        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1917        permanent tables. Instead, the bit maps for such a class were previously
1918        created as the appropriate unions of the upper, lower, and digit bitmaps.
1919        Now they are created by subtraction from the [[:word:]] class, which has
1920        its own bitmap.
1922     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1923        It is created by subtracting the vertical space characters (\x09, \x0a,
1924        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1925        subtraction was done in the overall bitmap for a character class, meaning
1926        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1927        be recognized. This bug has been fixed.
1929     7. Patches from the folks at Google:
1931          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1932          real life, but is still worth protecting against".
1934          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1935          regular expressions".
1937          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1938          have it.
1940          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1941          "configure" and the latter not, in order to fix a problem somebody had
1942          with compiling the Arg class on HP-UX.
1944          (e) Improve the error-handling of the C++ wrapper a little bit.
1946          (f) New tests for checking recursion limiting.
1948     8. The pcre_memmove() function, which is used only if the environment does not
1949        have a standard memmove() function (and is therefore rarely compiled),
1950        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1951        returning a result (though PCRE never actually uses the result).
1953     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1954        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1955        returned instead of calling malloc() with an overflowing number that would
1956        most likely cause subsequent chaos.
1958    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1960    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1961        with this option is matched, the nmatch and pmatch options of regexec() are
1962        ignored.
1964    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1965        provided in case anyone wants to the the POSIX interface with UTF-8
1966        strings.
1968    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1969        C++ linking (needed for some HP-UX environments).
1971    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1972        (unused parameter) and in the pcre_printint() function (omitted "default"
1973        switch label when the default is to do nothing).
1975    15. Added some code to make it possible, when PCRE is compiled as a C++
1976        library, to replace subject pointers for pcre_exec() with a smart pointer
1977        class, thus making it possible to process discontinuous strings.
1979    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1980        much the same function. They were added by different people who were trying
1981        to make PCRE easy to compile on non-Unix systems. It has been suggested
1982        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1983        for compiling on Windows systems. I have therefore replaced it with
1984        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1985        defaults to "extern" for C or "extern C" for C++, which works fine on
1986        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1987        SCOPE with something explicit in config.h. In addition:
1989        (a) pcreposix.h still had just "extern" instead of either of these macros;
1990            I have replaced it with PCRE_DATA_SCOPE.
1992        (b) Functions such as _pcre_xclass(), which are internal to the library,
1993            but external in the C sense, all had PCRE_EXPORT in their definitions.
1994            This is apparently wrong for the Windows case, so I have removed it.
1995            (It makes no difference on Unix-like systems.)
1997    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1998        of recursive calls to match(). This is different to MATCH_LIMIT because
1999        that limits the total number of calls to match(), not all of which increase
2000        the depth of recursion. Limiting the recursion depth limits the amount of
2001        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2002        when PCRE is compiled, and changed at run time. A patch from Google adds
2003        this functionality to the C++ interface.
2005    18. Changes to the handling of Unicode character properties:
2007        (a) Updated the table to Unicode 4.1.0.
2009        (b) Recognize characters that are not in the table as "Cn" (undefined).
2011        (c) I revised the way the table is implemented to a much improved format
2012            which includes recognition of ranges. It now supports the ranges that
2013            are defined in UnicodeData.txt, and it also amalgamates other
2014            characters into ranges. This has reduced the number of entries in the
2015            table from around 16,000 to around 3,000, thus reducing its size
2016            considerably. I realized I did not need to use a tree structure after
2017            all - a binary chop search is just as efficient. Having reduced the
2018            number of entries, I extended their size from 6 bytes to 8 bytes to
2019            allow for more data.
2021        (d) Added support for Unicode script names via properties such as \p{Han}.
2023    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2024        matching that character.
2026    20. When matching a repeated Unicode property with a minimum greater than zero,
2027        (for example \pL{2,}), PCRE could look past the end of the subject if it
2028        reached it while seeking the minimum number of characters. This could
2029        happen only if some of the characters were more than one byte long, because
2030        there is a check for at least the minimum number of bytes.
2032    21. Refactored the implementation of \p and \P so as to be more general, to
2033        allow for more different types of property in future. This has changed the
2034        compiled form incompatibly. Anybody with saved compiled patterns that use
2035        \p or \P will have to recompile them.
2037    22. Added "Any" and "L&" to the supported property types.
2039    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2040        but give a compile time error if the value is greater than 0xff.
2042    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2043        accidentally not being installed or uninstalled.
2045    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2046        made were to insert the current release number. This seemed silly, because
2047        it made things harder for people building PCRE on systems that don't run
2048        "configure". I have turned pcre.h into a distributed file, no longer built
2049        by "configure", with the version identification directly included. There is
2050        no longer a pcre.h.in file.
2052        However, this change necessitated a change to the pcre-config script as
2053        well. It is built from pcre-config.in, and one of the substitutions was the
2054        release number. I have updated configure.ac so that ./configure now finds
2055        the release number by grepping pcre.h.
2057    26. Added the ability to run the tests under valgrind.
2060    Version 6.4 05-Sep-05
2061    ---------------------
2063     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2064        "--" to be printed when multiple files were scanned, even when none of the
2065        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2066        consider it to be a bug, and have restored the previous behaviour.
2068     2. A couple of code tidies to get rid of compiler warnings.
2070     3. The pcretest program used to cheat by referring to symbols in the library
2071        whose names begin with _pcre_. These are internal symbols that are not
2072        really supposed to be visible externally, and in some environments it is
2073        possible to suppress them. The cheating is now confined to including
2074        certain files from the library's source, which is a bit cleaner.
2076     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2077        file's purpose clearer.
2079     5. Reorganized pcre_ucp_findchar().
2082    Version 6.3 15-Aug-05
2083    ---------------------
2085     1. The file libpcre.pc.in did not have general read permission in the tarball.
2087     2. There were some problems when building without C++ support:
2089        (a) If C++ support was not built, "make install" and "make test" still
2090            tried to test it.
2092        (b) There were problems when the value of CXX was explicitly set. Some
2093            changes have been made to try to fix these, and ...
2095        (c) --disable-cpp can now be used to explicitly disable C++ support.
2097        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2098            backslash in a target when C++ was disabled. This confuses some
2099            versions of "make", apparently. Using an intermediate variable solves
2100            this. (Same for CPP_LOBJ.)
2102     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2103        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2104        necessary on certain architectures.
2106     4. Added a setting of -export-symbols-regex to the link command to remove
2107        those symbols that are exported in the C sense, but actually are local
2108        within the library, and not documented. Their names all begin with
2109        "_pcre_". This is not a perfect job, because (a) we have to except some
2110        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2111        available (and never for static libraries). I have made a note to try to
2112        find a way round (a) in the future.
2115    Version 6.2 01-Aug-05
2116    ---------------------
2118     1. There was no test for integer overflow of quantifier values. A construction
2119        such as {1111111111111111} would give undefined results. What is worse, if
2120        a minimum quantifier for a parenthesized subpattern overflowed and became
2121        negative, the calculation of the memory size went wrong. This could have
2122        led to memory overwriting.
2124     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2126     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2127        operating environments where this matters.
2129     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2130        PCRE options from within the C++ wrapper.
2132     5. Named capturing subpatterns were not being correctly counted when a pattern
2133        was compiled. This caused two problems: (a) If there were more than 100
2134        such subpatterns, the calculation of the memory needed for the whole
2135        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2136        back references of the form \12, where the number was greater than 9, were
2137        not recognized as back references, even though there were sufficient
2138        previous subpatterns.
2140     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2141        versions of gcc, e.g. 2.95.4.
2144    Version 6.1 21-Jun-05
2145    ---------------------
2147     1. There was one reference to the variable "posix" in pcretest.c that was not
2148        surrounded by "#if !defined NOPOSIX".
2150     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2151        the cross-check on the old pcre_info() function, for the benefit of the
2152        cut-down version of PCRE that is currently imported into Exim.
2154     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2155        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2156        patterns that start (?i) but I don't think that matters. The use of (?i) is
2157        just an example; this all applies to the other options as well.
2159     4. Since libtool seems to echo the compile commands it is issuing, the output
2160        from "make" can be reduced a bit by putting "@" in front of each libtool
2161        compile command.
2163     5. Patch from the folks at Google for configure.in to be a bit more thorough
2164        in checking for a suitable C++ installation before trying to compile the
2165        C++ stuff. This should fix a reported problem when a compiler was present,
2166        but no suitable headers.
2168     6. The man pages all had just "PCRE" as their title. I have changed them to
2169        be the relevant file name. I have also arranged that these names are
2170        retained in the file doc/pcre.txt, which is a concatenation in text format
2171        of all the man pages except the little individual ones for each function.
2173     7. The NON-UNIX-USE file had not been updated for the different set of source
2174        files that come with release 6. I also added a few comments about the C++
2175        wrapper.
2178    Version 6.0 07-Jun-05
2179    ---------------------
2181     1. Some minor internal re-organization to help with my DFA experiments.
2183     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2184        didn't matter for the library itself when fully configured, but did matter
2185        when compiling without UCP support, or within Exim, where the ucp files are
2186        not imported.
2188     3. Refactoring of the library code to split up the various functions into
2189        different source modules. The addition of the new DFA matching code (see
2190        below) to a single monolithic source would have made it really too
2191        unwieldy, quite apart from causing all the code to be include in a
2192        statically linked application, when only some functions are used. This is
2193        relevant even without the DFA addition now that patterns can be compiled in
2194        one application and matched in another.
2196        The downside of splitting up is that there have to be some external
2197        functions and data tables that are used internally in different modules of
2198        the library but which are not part of the API. These have all had their
2199        names changed to start with "_pcre_" so that they are unlikely to clash
2200        with other external names.
2202     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2203        a different (DFA) algorithm. Although it is slower than the original
2204        function, it does have some advantages for certain types of matching
2205        problem.
2207     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2208        including restarting after a partial match.
2210     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2211        defined when compiling for Windows was sent to me. I have put it into the
2212        code, though I have no means of testing or verifying it.
2214     7. Added the pcre_refcount() auxiliary function.
2216     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2217        match before or at the first newline in the subject string. In pcretest,
2218        the /f option on a pattern can be used to set this.
2220     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2221        would behave wrongly. This has been present in PCRE since release 4.0.
2223    10. A number of changes to the pcregrep command:
2225        (a) Refactored how -x works; insert ^(...)$ instead of setting
2226            PCRE_ANCHORED and checking the length, in preparation for adding
2227            something similar for -w.
2229        (b) Added the -w (match as a word) option.
2231        (c) Refactored the way lines are read and buffered so as to have more
2232            than one at a time available.
2234        (d) Implemented a pcregrep test script.
2236        (e) Added the -M (multiline match) option. This allows patterns to match
2237            over several lines of the subject. The buffering ensures that at least
2238            8K, or the rest of the document (whichever is the shorter) is available
2239            for matching (and similarly the previous 8K for lookbehind assertions).
2241        (f) Changed the --help output so that it now says
2243              -w, --word-regex(p)
2245            instead of two lines, one with "regex" and the other with "regexp"
2246            because that confused at least one person since the short forms are the
2247            same. (This required a bit of code, as the output is generated
2248            automatically from a table. It wasn't just a text change.)
2250        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2251            option but starts with a hyphen. Could be a pattern or a path name
2252            starting with a hyphen, for instance.
2254        (h) "-" can be given as a file name to represent stdin.
2256        (i) When file names are being printed, "(standard input)" is used for
2257            the standard input, for compatibility with GNU grep. Previously
2258            "<stdin>" was used.
2260        (j) The option --label=xxx can be used to supply a name to be used for
2261            stdin when file names are being printed. There is no short form.
2263        (k) Re-factored the options decoding logic because we are going to add
2264            two more options that take data. Such options can now be given in four
2265            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2267        (l) Added the -A, -B, and -C options for requesting that lines of context
2268            around matches be printed.
2270        (m) Added the -L option to print the names of files that do not contain
2271            any matching lines, that is, the complement of -l.
2273        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2274            continue to scan other files.
2276        (o) The -s option was incorrectly implemented. For compatibility with other
2277            greps, it now suppresses the error message for a non-existent or non-
2278            accessible file (but not the return code). There is a new option called
2279            -q that suppresses the output of matching lines, which was what -s was
2280            previously doing.
2282        (p) Added --include and --exclude options to specify files for inclusion
2283            and exclusion when recursing.
2285    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2286        Hopefully, it now does.
2288    12. Missing cast in pcre_study().
2290    13. Added an "uninstall" target to the makefile.
2292    14. Replaced "extern" in the function prototypes in Makefile.in with
2293        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2294        world, but is set differently for Windows.
2296    15. Added a second compiling function called pcre_compile2(). The only
2297        difference is that it has an extra argument, which is a pointer to an
2298        integer error code. When there is a compile-time failure, this is set
2299        non-zero, in addition to the error test pointer being set to point to an
2300        error message. The new argument may be NULL if no error number is required
2301        (but then you may as well call pcre_compile(), which is now just a
2302        wrapper). This facility is provided because some applications need a
2303        numeric error indication, but it has also enabled me to tidy up the way
2304        compile-time errors are handled in the POSIX wrapper.
2306    16. Added VPATH=.libs to the makefile; this should help when building with one
2307        prefix path and installing with another. (Or so I'm told by someone who
2308        knows more about this stuff than I do.)
2310    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2311        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2312        match everything, including newlines. This is not POSIX-compatible, but
2313        somebody wanted the feature. From pcretest it can be activated by using
2314        both the P and the s flags.
2316    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2318    19. libpcre.pc was being incorrectly installed as executable.
2320    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2321        it now also looks for '\r' so that it will work unmodified on Windows.
2323    21. Added Google's contributed C++ wrapper to the distribution.
2325    22. Added some untidy missing memory free() calls in pcretest, to keep
2326        Electric Fence happy when testing.
2330    Version 5.0 13-Sep-04
2331    ---------------------
2333     1. Internal change: literal characters are no longer packed up into items
2334        containing multiple characters in a single byte-string. Each character
2335        is now matched using a separate opcode. However, there may be more than one
2336        byte in the character in UTF-8 mode.
2338     2. The pcre_callout_block structure has two new fields: pattern_position and
2339        next_item_length. These contain the offset in the pattern to the next match
2340        item, and its length, respectively.
2342     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2343        insertion of callouts before each pattern item. Added the /C option to
2344        pcretest to make use of this.
2346     4. On the advice of a Windows user, the lines
2348          #if defined(_WIN32) || defined(WIN32)
2349          _setmode( _fileno( stdout ), 0x8000 );
2350          #endif  /* defined(_WIN32) || defined(WIN32) */
2352        have been added to the source of pcretest. This apparently does useful
2353        magic in relation to line terminators.
2355     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2356        for the benefit of those environments where the "b" makes a difference.
2358     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2359        to know about it. I have put a hack into configure.in that adds in code
2360        to set GCC=yes if CC=icc. This seems to end up at a point in the
2361        generated configure script that is early enough to affect the setting of
2362        compiler options, which is what is needed, but I have no means of testing
2363        whether it really works. (The user who reported this had patched the
2364        generated configure script, which of course I cannot do.)
2366        LATER: After change 22 below (new libtool files), the configure script
2367        seems to know about icc (and also ecc). Therefore, I have commented out
2368        this hack in configure.in.
2370     7. Added support for pkg-config (2 patches were sent in).
2372     8. Negated POSIX character classes that used a combination of internal tables
2373        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2374        [[:^ascii]]. Typically, they would match almost any characters. The other
2375        POSIX classes were not broken in this way.
2377     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2378        to find the match, as PCRE was deluded into thinking that the match had to
2379        start at the start point or following a newline. The same bug applied to
2380        patterns with negative forward assertions or any backward assertions
2381        preceding ".*" at the start, unless the pattern required a fixed first
2382        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2384    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2385        starting at the last subject character, bytes beyond the end of the subject
2386        string were read.
2388    11. Renamed the variable "class" as "classbits" to make life easier for C++
2389        users. (Previously there was a macro definition, but it apparently wasn't
2390        enough.)
2392    12. Added the new field "tables" to the extra data so that tables can be passed
2393        in at exec time, or the internal tables can be re-selected. This allows
2394        a compiled regex to be saved and re-used at a later time by a different
2395        program that might have everything at different addresses.
2397    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2398        -R library as well as a -L library.
2400    14. The debugging options of pcretest (-d on the command line or D on a
2401        pattern) showed incorrect output for anything following an extended class
2402        that contained multibyte characters and which was followed by a quantifier.
2404    15. Added optional support for general category Unicode character properties
2405        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2406        support. It adds about 90K to the size of the library. The meanings of the
2407        inbuilt class escapes such as \d and \s have NOT been changed.
2409    16. Updated pcredemo.c to include calls to free() to release the memory for the
2410        compiled pattern.
2412    17. The generated file chartables.c was being created in the source directory
2413        instead of in the building directory. This caused the build to fail if the
2414        source directory was different from the building directory, and was
2415        read-only.
2417    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2418        file. No doubt somebody will tell me if they don't make sense... Also added
2419        Dan Mooney's comments about building on OpenVMS.
2421    19. Added support for partial matching via the PCRE_PARTIAL option for
2422        pcre_exec() and the \P data escape in pcretest.
2424    20. Extended pcretest with 3 new pattern features:
2426        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2427              write the compiled pattern to the file whose name is "rest-of-line".
2428              This is a straight binary dump of the data, with the saved pointer to
2429              the character tables forced to be NULL. The study data, if any, is
2430              written too. After writing, pcretest reads a new pattern.
2432        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2433              compiled pattern from the given file. There must not be any
2434              occurrences of "<" in the file name (pretty unlikely); if there are,
2435              pcretest will instead treat the initial "<" as a pattern delimiter.
2436              After reading in the pattern, pcretest goes on to read data lines as
2437              usual.
2439        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2440              and 16-bit fields in a compiled pattern, to simulate a pattern that
2441              was compiled on a host of opposite endianness.
2443    21. The pcre-exec() function can now cope with patterns that were compiled on
2444        hosts of opposite endianness, with this restriction:
2446          As for any compiled expression that is saved and used later, the tables
2447          pointer field cannot be preserved; the extra_data field in the arguments
2448          to pcre_exec() should be used to pass in a tables address if a value
2449          other than the default internal tables were used at compile time.
2451    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2452        now diagnosed as an error. Previously, most of the time, a negative number
2453        would have been treated as zero, but if in addition "ovector" was passed as
2454        NULL, a crash could occur.
2456    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2457        new versions from the libtool 1.5 distribution (the last one is a copy of
2458        a file called libtool.m4). This seems to have fixed the need to patch
2459        "configure" to support Darwin 1.3 (which I used to do). However, I still
2460        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2461        workstation).
2463    24. Changed the PCRE licence to be the more standard "BSD" licence.
2466    Version 4.5 01-Dec-03
2467    ---------------------
2469     1. There has been some re-arrangement of the code for the match() function so
2470        that it can be compiled in a version that does not call itself recursively.
2471        Instead, it keeps those local variables that need separate instances for
2472        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2473        needs to "recurse". Keeping track of where control must go is done by means
2474        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2475        hide most of the details from the main code, and operates only if
2476        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2477        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2478        operating.
2480        To make it easier for callers to provide specially tailored get/free
2481        functions for this usage, two new functions, pcre_stack_malloc, and
2482        pcre_stack_free, are used. They are always called in strict stacking order,
2483        and the size of block requested is always the same.
2485        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2486        PCRE has been compiled to use the stack or the heap for recursion. The
2487        -C option of pcretest uses this to show which version is compiled.
2489        A new data escape \S, is added to pcretest; it causes the amounts of store
2490        obtained and freed by both kinds of malloc/free at match time to be added
2491        to the output.
2493     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2494        what's available on my current Linux desktop machine.
2496     3. When matching a UTF-8 string, the test for a valid string at the start has
2497        been extended. If start_offset is not zero, PCRE now checks that it points
2498        to a byte that is the start of a UTF-8 character. If not, it returns
2499        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2500        this is necessary because there may be backward assertions in the pattern.
2501        When matching the same subject several times, it may save resources to use
2502        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2504     4. The code for checking the validity of UTF-8 strings has been tightened so
2505        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2506        containing "overlong sequences".
2508     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2509        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2510        should have been "&", but it just so happened that all the cases this let
2511        through by mistake were picked up later in the function.
2513     6. I had used a variable called "isblank" - this is a C99 function, causing
2514        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2516     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2517        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2518        so the version is shown; (c) stop "make test" echoing "./RunTest".
2520     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2522     9. The prototype for memmove() for systems that don't have it was using
2523        size_t, but the inclusion of the header that defines size_t was later. I've
2524        moved the #includes for the C headers earlier to avoid this.
2526    10. Added some adjustments to the code to make it easier to compiler on certain
2527        special systems:
2529          (a) Some "const" qualifiers were missing.
2530          (b) Added the macro EXPORT before all exported functions; by default this
2531              is defined to be empty.
2532          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2533              that it reads its output file name as an argument instead of writing
2534              to the standard output and assuming this can be redirected.
2536    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2537        class containing characters with values greater than 255, PCRE compilation
2538        went into a loop.
2540    12. A recursive reference to a subpattern that was within another subpattern
2541        that had a minimum quantifier of zero caused PCRE to crash. For example,
2542        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2543        recursion. If the recursively-called subpattern itself had a zero repeat,
2544        that was OK.
2546    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2547        buffer into which it was copied (for escape processing) was still set at
2548        1024, so long lines caused crashes.
2550    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2551        "internal error: code overflow...". This applied to any character class
2552        that was followed by a possessive quantifier.
2554    15. Modified the Makefile to add libpcre.la as a prerequisite for
2555        libpcreposix.la because I was told this is needed for a parallel build to
2556        work.
2558    16. If a pattern that contained .* following optional items at the start was
2559        studied, the wrong optimizing data was generated, leading to matching
2560        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2561        matching string must start with a or b or c. The correct conclusion for
2562        this pattern is that a match can start with any character.
2565    Version 4.4 13-Aug-03
2566    ---------------------
2568     1. In UTF-8 mode, a character class containing characters with values between
2569        127 and 255 was not handled correctly if the compiled pattern was studied.
2570        In fixing this, I have also improved the studying algorithm for such
2571        classes (slightly).
2573     2. Three internal functions had redundant arguments passed to them. Removal
2574        might give a very teeny performance improvement.
2576     3. Documentation bug: the value of the capture_top field in a callout is *one
2577        more than* the number of the hightest numbered captured substring.
2579     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2580        in incorrectly linking with a previously installed version. They now link
2581        explicitly with libpcre.la.
2583     5. configure.in no longer needs to recognize Cygwin specially.
2585     6. A problem in pcre.in for Windows platforms is fixed.
2587     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2588        pcretest, it used to include the size of the study block as part of its
2589        output. Unfortunately, the structure contains a field that has a different
2590        size on different hardware architectures. This meant that the tests that
2591        showed this size failed. As the block is currently always of a fixed size,
2592        this information isn't actually particularly useful in pcretest output, so
2593        I have just removed it.
2595     8. Three pre-processor statements accidentally did not start in column 1.
2596        Sadly, there are *still* compilers around that complain, even though
2597        standard C has not required this for well over a decade. Sigh.
2599     9. In pcretest, the code for checking callouts passed small integers in the
2600        callout_data field, which is a void * field. However, some picky compilers
2601        complained about the casts involved for this on 64-bit systems. Now
2602        pcretest passes the address of the small integer instead, which should get
2603        rid of the warnings.
2605    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2606        both compile and run time, and gives an error if an invalid UTF-8 sequence
2607        is found. There is a option for disabling this check in cases where the
2608        string is known to be correct and/or the maximum performance is wanted.
2610    11. In response to a bug report, I changed one line in Makefile.in from
2612            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2613        to
2614            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2616        to look similar to other lines, but I have no way of telling whether this
2617        is the right thing to do, as I do not use Windows. No doubt I'll get told
2618        if it's wrong...
2621    Version 4.3 21-May-03
2622    ---------------------
2624    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2625       Makefile.
2627    2. Some refactoring to improve the quality of the code:
2629       (i)   The utf8_table... variables are now declared "const".
2631       (ii)  The code for \cx, which used the "case flipping" table to upper case
2632             lower case letters, now just substracts 32. This is ASCII-specific,
2633             but the whole concept of \cx is ASCII-specific, so it seems
2634             reasonable.
2636       (iii) PCRE was using its character types table to recognize decimal and
2637             hexadecimal digits in the pattern. This is silly, because it handles
2638             only 0-9, a-f, and A-F, but the character types table is locale-
2639             specific, which means strange things might happen. A private
2640             table is now used for this - though it costs 256 bytes, a table is
2641             much faster than multiple explicit tests. Of course, the standard
2642             character types table is still used for matching digits in subject
2643             strings against \d.
2645       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2646             ending in _t are). So I've renamed it as ESC_tee.
2648    3. The first argument for regexec() in the POSIX wrapper should have been
2649       defined as "const".
2651    4. Changed pcretest to use malloc() for its buffers so that they can be
2652       Electric Fenced for debugging.
2654    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2655       to read one or more bytes before the start of the subject string. Often this
2656       had no effect on PCRE's behaviour, but in some circumstances it could
2657       provoke a segmentation fault.
2659    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2660       to try to read one or more bytes before the start of the subject string.
2662    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2663       UTF-8 support could misbehave in various ways if the subject string
2664       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2665       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2666       back over UTF-8 characters.)
2669    Version 4.2 14-Apr-03
2670    ---------------------
2672    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2674    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2675         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2676         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2677         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2678         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2679           and BUILD_EXEEXT
2680         Note: automatic setting of the BUILD variables is not yet working
2681         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2682           compile-time but not at link-time
2683         [LINK]: use for linking executables only
2684         make different versions for Windows and non-Windows
2685         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2686           libraries
2687         [LINK_FOR_BUILD]: new variable
2688         [OBJEXT]: use throughout
2689         [EXEEXT]: use throughout
2690         <winshared>: new target
2691         <wininstall>: new target
2692         <dftables.o>: use native compiler
2693         <dftables>: use native linker
2694         <install>: handle Windows platform correctly
2695         <clean>: ditto
2696         <check>: ditto
2697         copy DLL to top builddir before testing
2699       As part of these changes, -no-undefined was removed again. This was reported
2700       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2701       in any case.
2703    3. Some tidies to get rid of compiler warnings:
2705       . In the match_data structure, match_limit was an unsigned long int, whereas
2706         match_call_count was an int. I've made them both unsigned long ints.
2708       . In pcretest the fact that a const uschar * doesn't automatically cast to
2709         a void * provoked a warning.
2711       . Turning on some more compiler warnings threw up some "shadow" variables
2712         and a few more missing casts.
2714    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2715       option, a class that contained a single character with a value between 128
2716       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2718    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2719       option, a class that contained several characters, but with at least one
2720       whose value was between 128 and 255 caused PCRE to crash.
2723    Version 4.1 12-Mar-03
2724    ---------------------
2726    1. Compiling with gcc -pedantic found a couple of places where casts were
2727    needed, and a string in dftables.c that was longer than standard compilers are
2728    required to support.
2730    2. Compiling with Sun's compiler found a few more places where the code could
2731    be tidied up in order to avoid warnings.
2733    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2734    first of these names is deprecated in the latest Autoconf in favour of the name
2735    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2736    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2737    analogy I have changed it to CFLAGS_FOR_BUILD.
2739    4. Added -no-undefined to the linking command in the Makefile, because this is
2740    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2741    linking step for the pcreposix library.
2743    5. PCRE was failing to diagnose the case of two named groups with the same
2744    name.
2746    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2747    literal character that is needed in the subject for a match, and scans along to
2748    ensure that it is present before embarking on the full matching process. This
2749    saves time in cases of nested unlimited repeats that are never going to match.
2750    Problem: the scan can take a lot of time if the subject is very long (e.g.
2751    megabytes), thus penalizing straightforward matches. It is now done only if the
2752    amount of subject to be scanned is less than 1000 bytes.
2754    7. A lesser problem with the same optimization is that it was recording the
2755    first character of an anchored pattern as "needed", thus provoking a search
2756    right along the subject, even when the first match of the pattern was going to
2757    fail. The "needed" character is now not set for anchored patterns, unless it
2758    follows something in the pattern that is of non-fixed length. Thus, it still
2759    fulfils its original purpose of finding quick non-matches in cases of nested
2760    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2763    Version 4.0 17-Feb-03
2764    ---------------------
2766    1. If a comment in an extended regex that started immediately after a meta-item
2767    extended to the end of string, PCRE compiled incorrect data. This could lead to
2768    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2770    2. Moved to autoconf 2.53 and libtool 1.4.2.
2772    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2773    the special perltest8 script is no longer needed - all the tests can be run
2774    from a single perltest script.
2776    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2777    by \s. It has now been removed in PCRE. This means it isn't recognized as
2778    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2779    class [:space:] *does* include VT, thereby creating a mess.
2781    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2782    space and tab.
2784    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2785    its new features into the main test script, reducing the number of scripts.
2787    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2788    were backward compatible, and made the (?i) apply to the whole pattern, as if
2789    /i were given. Now it behaves more logically, and applies the option setting
2790    only to what follows. PCRE has been changed to follow suit. However, if it
2791    finds options settings right at the start of the pattern, it extracts them into
2792    the global options, as before. Thus, they show up in the info data.
2794    8. Added support for the \Q...\E escape sequence. Characters in between are
2795    treated as literals. This is slightly different from Perl in that $ and @ are
2796    also handled as literals inside the quotes. In Perl, they will cause variable
2797    interpolation. Note the following examples:
2799        Pattern            PCRE matches      Perl matches
2801        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2802        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2803        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2805    For compatibility with Perl, \Q...\E sequences are recognized inside character
2806    classes as well as outside them.
2808    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2809    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2810    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2811    signed/unsigned warnings.
2813    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2814    option for pcretest, so I've replaced it by a simple function that does just
2815    that job.
2817    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2818    "pcregrep -".
2820    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2821    Java package. This provides some syntactic sugar for simple cases of what my
2822    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2823    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2824    item, you can use this simplified notation. Note that only makes sense with
2825    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2826    greediness, whatever the setting of the PCRE_UNGREEDY option.
2828    13. A change of greediness default within a pattern was not taking effect at
2829    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2830    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2831    was abstracted outside.
2833    14. PCRE now supports the \G assertion. It is true when the current matching
2834    position is at the start point of the match. This differs from \A when the
2835    starting offset is non-zero. Used with the /g option of pcretest (or similar
2836    code), it works in the same way as it does for Perl's /g option. If all
2837    alternatives of a regex begin with \G, the expression is anchored to the start
2838    match position, and the "anchored" flag is set in the compiled expression.
2840    15. Some bugs concerning the handling of certain option changes within patterns
2841    have been fixed. These applied to options other than (?ims). For example,
2842    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2843    been the other way round. Some of this was related to change 7 above.
2845    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2846    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2847    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2848    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2850    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2851    mode. Unlike ".", it always matches newline, whatever the setting of
2852    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2853    assertions. Perl allows it, but it doesn't (in general) work because it can't
2854    calculate the length of the lookbehind. At least, that's the case for Perl
2855    5.8.0 - I've been told they are going to document that it doesn't work in
2856    future.
2858    18. Added an error diagnosis for escapes that PCRE does not support: these are
2859    \L, \l, \N, \P, \p, \U, \u, and \X.
2861    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2862    reading past the end of the pattern in cases such as /[abcd/.
2864    20. PCRE was getting more memory than necessary for patterns with classes that
2865    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2867    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2868    compiling PCRE for use with Virtual Pascal.
2870    22. Small fix to the Makefile to make it work properly if the build is done
2871    outside the source tree.
2873    23. Added a new extension: a condition to go with recursion. If a conditional
2874    subpattern starts with (?(R) the "true" branch is used if recursion has
2875    happened, whereas the "false" branch is used only at the top level.
2877    24. When there was a very long string of literal characters (over 255 bytes
2878    without UTF support, over 250 bytes with UTF support), the computation of how
2879    much memory was required could be incorrect, leading to segfaults or other
2880    strange effects.
2882    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2883    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2884    there was a subsequent back reference to those brackets. This meant that, for
2885    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2886    possible to check for precisely this case. All we can do is abandon the
2887    optimization if .* occurs inside capturing brackets when there are any back
2888    references whatsoever. (See below for a better fix that came later.)
2890    26. The handling of the optimization for finding the first character of a
2891    non-anchored pattern, and for finding a character that is required later in the
2892    match were failing in some cases. This didn't break the matching; it just
2893    failed to optimize when it could. The way this is done has been re-implemented.
2895    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2897    28. Added a new feature that provides some of the functionality that Perl
2898    provides with (?{...}). The facility is termed a "callout". The way it is done
2899    in PCRE is for the caller to provide an optional function, by setting
2900    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2901    global variable. By default it is unset, which disables all calling out. To get
2902    the function called, the regex must include (?C) at appropriate points. This
2903    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2904    This provides a means of identifying different callout points. When PCRE
2905    reaches such a point in the regex, if pcre_callout has been set, the external
2906    function is called. It is provided with data in a structure called
2907    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2908    matching continues; if it returns a non-zero value, the match at the current
2909    point fails. However, backtracking will occur if possible. [This was changed
2910    later and other features added - see item 49 below.]
2912    29. pcretest is upgraded to test the callout functionality. It provides a
2913    callout function that displays information. By default, it shows the start of
2914    the match and the current position in the text. There are some new data escapes
2915    to vary what happens:
2917        \C+         in addition, show current contents of captured substrings
2918        \C-         do not supply a callout function
2919        \C!n        return 1 when callout number n is reached
2920        \C!n!m      return 1 when callout number n is reached for the mth time
2922    30. If pcregrep was called with the -l option and just a single file name, it
2923    output "<stdin>" if a match was found, instead of the file name.
2925    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2926    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2927    pcre_exec(). This saves a malloc/free per call. The default value of
2928    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2929    when configuring.
2931    32. The default maximum size of a compiled pattern is 64K. There have been a
2932    few cases of people hitting this limit. The code now uses macros to handle the
2933    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2934    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2935    configuring. Tests 2 and 5 work only with 2-byte links because they output
2936    debugging information about compiled patterns.
2938    33. Internal code re-arrangements:
2940    (a) Moved the debugging function for printing out a compiled regex into
2941        its own source file (printint.c) and used #include to pull it into
2942        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2943        separate copies.
2945    (b) Defined the list of op-code names for debugging as a macro in
2946        internal.h so that it is next to the definition of the opcodes.
2948    (c) Defined a table of op-code lengths for simpler skipping along compiled
2949        code. This is again a macro in internal.h so that it is next to the
2950        definition of the opcodes.
2952    34. Added support for recursive calls to individual subpatterns, along the
2953    lines of Robin Houston's patch (but implemented somewhat differently).
2955    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2956    allow it to read and process whole directories in Win32. This code was
2957    contributed by Lionel Fourquaux; it has not been tested by me.
2959    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2960    used to name a group. Names consist of alphanumerics and underscores, and must
2961    be unique. Back references use the syntax (?P=name) and recursive calls use
2962    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2963    numbers. The function pcre_fullinfo() can be used after compilation to extract
2964    a name/number map. There are three relevant calls:
2966      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
2967      PCRE_INFO_NAMECOUNT            yields the number of entries
2968      PCRE_INFO_NAMETABLE            yields a pointer to the map.
2970    The map is a vector of fixed-size entries. The size of each entry depends on
2971    the length of the longest name used. The first two bytes of each entry are the
2972    group number, most significant byte first. There follows the corresponding
2973    name, zero terminated. The names are in alphabetical order.
2975    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2976    case instead of 255. Making it the same both with and without UTF-8 support
2977    means that the same test output works with both.
2979    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2980    calling malloc() with a zero argument.
2982    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2983    optimization. I've improved things by keeping a bitmap of backreferences with
2984    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2985    fact referenced, the optimization can be applied. It is unlikely that a
2986    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2987    the match to follow \n) will appear inside brackets with a number greater than
2988    31, but if it does, any back reference > 31 suppresses the optimization.
2990    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2991    of disabling numbered capturing parentheses. Any opening parenthesis that is
2992    not followed by ? behaves as if it were followed by ?: but named parentheses
2993    can still be used for capturing (and they will acquire numbers in the usual
2994    way).
2996    41. Redesigned the return codes from the match() function into yes/no/error so
2997    that errors can be passed back from deep inside the nested calls. A malloc
2998    failure while inside a recursive subpattern call now causes the
2999    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3001    42. It is now possible to set a limit on the number of times the match()
3002    function is called in a call to pcre_exec(). This facility makes it possible to
3003    limit the amount of recursion and backtracking, though not in a directly
3004    obvious way, because the match() function is used in a number of different
3005    circumstances. The count starts from zero for each position in the subject
3006    string (for non-anchored patterns). The default limit is, for compatibility, a
3007    large number, namely 10 000 000. You can change this in two ways:
3009    (a) When configuring PCRE before making, you can use --with-match-limit=n
3010        to set a default value for the compiled library.
3012    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3013        a different value is set. See 45 below.
3015    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3017    43. Added a new function pcre_config(int, void *) to enable run-time extraction
3018    of things that can be changed at compile time. The first argument specifies
3019    what is wanted and the second points to where the information is to be placed.
3020    The current list of available information is:
3022      PCRE_CONFIG_UTF8
3024    The output is an integer that is set to one if UTF-8 support is available;
3025    otherwise it is set to zero.
3029    The output is an integer that it set to the value of the code that is used for
3030    newline. It is either LF (10) or CR (13).
3034    The output is an integer that contains the number of bytes used for internal
3035    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3039    The output is an integer that contains the threshold above which the POSIX
3040    interface uses malloc() for output vectors. See item 31 above.
3044    The output is an unsigned integer that contains the default limit of the number
3045    of match() calls in a pcre_exec() execution. See 42 above.
3047    44. pcretest has been upgraded by the addition of the -C option. This causes it
3048    to extract all the available output from the new pcre_config() function, and to
3049    output it. The program then exits immediately.
3051    45. A need has arisen to pass over additional data with calls to pcre_exec() in
3052    order to support additional features. One way would have been to define
3053    pcre_exec2() (for example) with extra arguments, but this would not have been
3054    extensible, and would also have required all calls to the original function to
3055    be mapped to the new one. Instead, I have chosen to extend the mechanism that
3056    is used for passing in "extra" data from pcre_study().
3058    The pcre_extra structure is now exposed and defined in pcre.h. It currently
3059    contains the following fields:
3061      flags         a bitmap indicating which of the following fields are set
3062      study_data    opaque data from pcre_study()
3063      match_limit   a way of specifying a limit on match() calls for a specific
3064                      call to pcre_exec()
3065      callout_data  data for callouts (see 49 below)
3067    The flag bits are also defined in pcre.h, and are
3073    The pcre_study() function now returns one of these new pcre_extra blocks, with
3074    the actual study data pointed to by the study_data field, and the
3075    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3076    before. That is, this change is entirely upwards-compatible and requires no
3077    change to existing code.
3079    If you want to pass in additional data to pcre_exec(), you can either place it
3080    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3081    block.
3083    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3084    data string contains the escape sequence \M, pcretest calls pcre_exec() several
3085    times with different match limits, until it finds the minimum value needed for
3086    pcre_exec() to complete. The value is then output. This can be instructive; for
3087    most simple matches the number is quite small, but for pathological cases it
3088    gets very large very quickly.
3090    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3091    returns the size of the data block pointed to by the study_data field in a
3092    pcre_extra block, that is, the value that was passed as the argument to
3093    pcre_malloc() when PCRE was getting memory in which to place the information
3094    created by pcre_study(). The fourth argument should point to a size_t variable.
3095    pcretest has been extended so that this information is shown after a successful
3096    pcre_study() call when information about the compiled regex is being displayed.
3098    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3099    because what follows is always an absolute path. (Later: it turns out that this
3100    is more than cosmetic for MinGW, because it doesn't like empty path
3101    components.)
3103    49. Some changes have been made to the callout feature (see 28 above):
3105    (i)  A callout function now has three choices for what it returns:
3107           0  =>  success, carry on matching
3108         > 0  =>  failure at this point, but backtrack if possible
3109         < 0  =>  serious error, return this value from pcre_exec()
3111         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3112         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3113         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3114         use by callout functions. It will never be used by PCRE itself.
3116    (ii) The pcre_extra structure (see 45 above) has a void * field called
3117         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3118         pcre_callout_block structure has a field of the same name. The contents of
3119         the field passed in the pcre_extra structure are passed to the callout
3120         function in the corresponding field in the callout block. This makes it
3121         easier to use the same callout-containing regex from multiple threads. For
3122         testing, the pcretest program has a new data escape
3124           \C*n        pass the number n (may be negative) as callout_data
3126         If the callout function in pcretest receives a non-zero value as
3127         callout_data, it returns that value.
3129    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3130    there were some redundant $(CFLAGS) in commands that are now specified as
3131    $(LINK), which already includes $(CFLAGS).
3133    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3134    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3135    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3136    one-byte characters throughout. Note that case-insensitive matching applies
3137    only to characters whose values are less than 256. PCRE doesn't support the
3138    notion of cases for higher-valued characters.
3140    (i)   A character class whose characters are all within 0-255 is handled as
3141          a bit map, and the map is inverted for negative classes. Previously, a
3142          character > 255 always failed to match such a class; however it should
3143          match if the class was a negative one (e.g. [^ab]). This has been fixed.
3145    (ii)  A negated character class with a single character < 255 is coded as
3146          "not this character" (OP_NOT). This wasn't working properly when the test
3147          character was multibyte, either singly or repeated.
3149    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3150          mode, for example: \x{100}{2,3}.
3152    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3153          singly or repeated) now correctly test multibyte characters. However,
3154          PCRE doesn't recognize any characters with values greater than 255 as
3155          digits, spaces, or word characters. Such characters always match \D, \S,
3156          and \W, and never match \d, \s, or \w.
3158    (v)   Classes may now contain characters and character ranges with values
3159          greater than 255. For example: [ab\x{100}-\x{400}].
3161    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
3162          PCRE in UTF-8 mode.
3164    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3165    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3166    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3167    value.)
3169    53. The single man page has become too large. I have therefore split it up into
3170    a number of separate man pages. These also give rise to individual HTML pages;
3171    these are now put in a separate directory, and there is an index.html page that
3172    lists them all. Some hyperlinking between the pages has been installed.
3174    54. Added convenience functions for handling named capturing parentheses.
3176    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3177    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3178    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3179    are faulted.
3181    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3182    calling configure. These values are used when compiling the dftables.c program
3183    which is run to generate the source of the default character tables. They
3184    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3185    you will need to set these values.
3187    57. Updated the building process for Windows DLL, as provided by Fred Cox.
3190    Version 3.9 02-Jan-02
3191    ---------------------
3193    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3195    2. If --disable-static was given, the building process failed when trying to
3196    build pcretest and pcregrep. (For some reason it was using libtool to compile
3197    them, which is not right, as they aren't part of the library.)
3200    Version 3.8 18-Dec-01
3201    ---------------------
3203    1. The experimental UTF-8 code was completely screwed up. It was packing the
3204    bytes in the wrong order. How dumb can you get?
3207    Version 3.7 29-Oct-01
3208    ---------------------
3210    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3211    This caused pcretest, when used on the test data, to segfault. Unfortunately,
3212    this didn't happen under Solaris 8, where I normally test things.
3214    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3215    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3216    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3217    this fix an hour or so after the initial 3.7 release.)
3220    Version 3.6 23-Oct-01
3221    ---------------------
3223    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3224    offsets passed as NULL with zero offset count.
3226    2. The config.guess and config.sub files had not been updated when I moved to
3227    the latest autoconf.
3230    Version 3.5 15-Aug-01
3231    ---------------------
3233    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3234    had been forgotten.
3236    2. By using declared but undefined structures, we can avoid using "void"
3237    definitions in pcre.h while keeping the internal definitions of the structures
3238    private.
3240    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3241    user point of view, this means that both static and shared libraries are built
3242    by default, but this can be individually controlled. More of the work of
3243    handling this static/shared cases is now inside libtool instead of PCRE's make
3244    file.
3246    4. The pcretest utility is now installed along with pcregrep because it is
3247    useful for users (to test regexs) and by doing this, it automatically gets
3248    relinked by libtool. The documentation has been turned into a man page, so
3249    there are now .1, .txt, and .html versions in /doc.
3251    5. Upgrades to pcregrep:
3252       (i)   Added long-form option names like gnu grep.
3253       (ii)  Added --help to list all options with an explanatory phrase.
3254       (iii) Added -r, --recursive to recurse into sub-directories.
3255       (iv)  Added -f, --file to read patterns from a file.
3257    6. pcre_exec() was referring to its "code" argument before testing that
3258    argument for NULL (and giving an error if it was NULL).
3260    7. Upgraded Makefile.in to allow for compiling in a different directory from
3261    the source directory.
3263    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3264    options bits, the pointer it was passed was to an int instead of to an unsigned
3265    long int. This mattered only on 64-bit systems.
3267    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3268    generated) instead of pcre.in, which it its source. Also made the same change
3269    in several of the .c files.
3271    10. A new release of gcc defines printf() as a macro, which broke pcretest
3272    because it had an ifdef in the middle of a string argument for printf(). Fixed
3273    by using separate calls to printf().
3275    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3276    script, to force use of CR or LF instead of \n in the source. On non-Unix
3277    systems, the value can be set in config.h.
3279    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3280    absolute limit. Changed the text of the error message to make this clear, and
3281    likewise updated the man page.
3283    13. The limit of 99 on the number of capturing subpatterns has been removed.
3284    The new limit is 65535, which I hope will not be a "real" limit.
3287    Version 3.4 22-Aug-00
3288    ---------------------
3290    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3292    2. Diagnose condition (?(0) as an error instead of crashing on matching.
3295    Version 3.3 01-Aug-00
3296    ---------------------
3298    1. If an octal character was given, but the value was greater than \377, it
3299    was not getting masked to the least significant bits, as documented. This could
3300    lead to crashes in some systems.
3302    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3303    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3305    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3306    These just pass their arguments on to (pcre_free)(), but they are provided
3307    because some uses of PCRE bind it to non-C systems that can call its functions,
3308    but cannot call free() or pcre_free() directly.
3310    4. Add "make test" as a synonym for "make check". Corrected some comments in
3311    the Makefile.
3313    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3314    Makefile.
3316    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3317    command called pgrep for grepping around the active processes.
3319    7. Added the beginnings of support for UTF-8 character strings.
3321    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3322    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3323    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3324    out for the ar command.)
3327    Version 3.2 12-May-00
3328    ---------------------
3330    This is purely a bug fixing release.
3332    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3333    of ZA. This was just one example of several cases that could provoke this bug,
3334    which was introduced by change 9 of version 2.00. The code for breaking
3335    infinite loops after an iteration that matches an empty string was't working
3336    correctly.
3338    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3339    when matched against abbab (for example). After matching an empty string, it
3340    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3341    caused it to match further down the string than it should.
3343    3. The code contained an inclusion of sys/types.h. It isn't clear why this
3344    was there because it doesn't seem to be needed, and it causes trouble on some
3345    systems, as it is not a Standard C header. It has been removed.
3347    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3348    were reported on the Macintosh. The changes were from
3350      while ((c = *(++ptr)) != 0 && c != '\n');
3351    to
3352      while ((c = *(++ptr)) != 0 && c != '\n') ;
3354    Totally extraordinary, but if that's what it takes...
3356    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3357    available. Added HAVE_BCOPY and an autoconf test for it; if neither
3358    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3359    assumes the way PCRE uses memmove() (always moving upwards).
3361    6. PCRE is being used in one environment where strchr() is not available. There
3362    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3363    faster code anyway.
3366  Version 3.1 09-Feb-00  Version 3.1 09-Feb-00
3367  ---------------------  ---------------------

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