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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.13 30-Apr-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
126    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127        subject after a captured substring (to make it easier to tell which of a
128        number of identical substrings has been captured).
130    24. The way atomic groups are processed by pcre_exec() has been changed so that
131        if they are repeated, backtracking one repetition now resets captured
132        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134        "aaa". Previously, it would have been "a". As part of this code
135        refactoring, the way recursive calls are handled has also been changed.
138    Version 8.12 15-Jan-2011
139    ------------------------
141    1.  Fixed some typos in the markup of the man pages, and wrote a script that
142        checks for such things as part of the documentation building process.
144    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
145        --match-limit and --recursion-limit options (added for 8.11). In
146        particular, this made one of the standard tests fail. (The integer value
147        went into the wrong half of a long int.)
149    3.  If the --colour option was given to pcregrep with -v (invert match), it
150        did strange things, either producing crazy output, or crashing. It should,
151        of course, ignore a request for colour when reporting lines that do not
152        match.
154    4.  Another pcregrep bug caused similar problems if --colour was specified with
155        -M (multiline) and the pattern match finished with a line ending.
157    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
158        matched in multiline mode, the following line was shown as part of the
159        match. This seems wrong, so I have changed it.
161    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
162        the check for further matches in the same line (so they could be coloured)
163        to overrun the end of the current line. If another match was found, it was
164        incorrectly shown (and then shown again when found in the next line).
166    7.  If pcregrep was compiled under Windows, there was a reference to the
167        function pcregrep_exit() before it was defined. I am assuming this was
168        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
169        reported by a user. I've moved the definition above the reference.
172    Version 8.11 10-Dec-2010
173    ------------------------
175    1.  (*THEN) was not working properly if there were untried alternatives prior
176        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
177        backtracked to try for "b" instead of moving to the next alternative branch
178        at the same level (in this case, to look for "c"). The Perl documentation
179        is clear that when (*THEN) is backtracked onto, it goes to the "next
180        alternative in the innermost enclosing group".
182    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
183        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
184        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
185        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
186        (*THEN).
188    3.  If \s appeared in a character class, it removed the VT character from
189        the class, even if it had been included by some previous item, for example
190        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
191        of \s, but is part of the POSIX "space" class.)
193    4.  A partial match never returns an empty string (because you can always
194        match an empty string at the end of the subject); however the checking for
195        an empty string was starting at the "start of match" point. This has been
196        changed to the "earliest inspected character" point, because the returned
197        data for a partial match starts at this character. This means that, for
198        example, /(?<=abc)def/ gives a partial match for the subject "abc"
199        (previously it gave "no match").
201    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
202        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
203        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
204        has an implication that the given string is incomplete (because a partial
205        match is preferred over a full match). For this reason, these items now
206        give a partial match in this situation. [Aside: previously, the one case
207        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
208        match rather than a full match, which was wrong by the old rules, but is
209        now correct.]
211    6.  There was a bug in the handling of #-introduced comments, recognized when
212        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
213        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
214        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
215        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
216        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
217        places in pcre_compile().
219    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
220        comments when looking ahead for named forward references to subpatterns,
221        the only newline sequence it recognized was NL. It now handles newlines
222        according to the set newline convention.
224    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
225        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
226        cater for a lack of strerror(). These oversights have been fixed.
228    9.  Added --match-limit and --recursion-limit to pcregrep.
230    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
232    11. When the -o option was used, pcregrep was setting a return code of 1, even
233        when matches were found, and --line-buffered was not being honoured.
235    12. Added an optional parentheses number to the -o and --only-matching options
236        of pcregrep.
238    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
239        can match an empty string. The code to do it in pcretest and pcredemo
240        needed fixing:
242        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
243            only one byte after an empty string match just before CRLF (this case
244            just got forgotten; "any" and "anycrlf" were OK).
246        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
247            mode when an empty string match preceded an ASCII character followed by
248            a non-ASCII character. (The code for advancing by one character rather
249            than one byte was nonsense.)
251        (c) The pcredemo.c sample program did not have any code at all to handle
252            the cases when CRLF is a valid newline sequence.
254    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
255        as a starting offset was within the subject string. There is now a new
256        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
257        negative or greater than the length of the string. In order to test this,
258        pcretest is extended to allow the setting of negative starting offsets.
260    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
261        starting offset points to the beginning of a UTF-8 character was
262        unnecessarily clumsy. I tidied it up.
264    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
265        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
267    17. Nobody had reported that the --include_dir option, which was added in
268        release 7.7 should have been called --include-dir (hyphen, not underscore)
269        for compatibility with GNU grep. I have changed it to --include-dir, but
270        left --include_dir as an undocumented synonym, and the same for
271        --exclude-dir, though that is not available in GNU grep, at least as of
272        release 2.5.4.
274    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
275        characters from a string of bytes) have been redefined so as not to use
276        loops, in order to improve performance in some environments. At the same
277        time, I abstracted some of the common code into auxiliary macros to save
278        repetition (this should not affect the compiled code).
280    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
281        compile-time error is now given if \c is not followed by an ASCII
282        character, that is, a byte less than 128. (In EBCDIC mode, the code is
283        different, and any byte value is allowed.)
285    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
286        START_OPTIMIZE option, which is now allowed at compile time - but just
287        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
288        to pcregrep and other applications that have no direct access to PCRE
289        options. The new /Y option in pcretest sets this option when calling
290        pcre_compile().
292    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
293        back references. Groups containing recursive back references were forced to
294        be atomic by that change, but in the case of named groups, the amount of
295        memory required was incorrectly computed, leading to "Failed: internal
296        error: code overflow". This has been fixed.
298    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
299        pcretest.c, to avoid build problems in some Borland environments.
302    Version 8.10 25-Jun-2010
303    ------------------------
305    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
306        THEN.
308    2.  (*ACCEPT) was not working when inside an atomic group.
310    3.  Inside a character class, \B is treated as a literal by default, but
311        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
312        causes the error). The code is unchanged, but I tidied the documentation.
314    4.  Inside a character class, PCRE always treated \R and \X as literals,
315        whereas Perl faults them if its -w option is set. I have changed PCRE so
316        that it faults them when PCRE_EXTRA is set.
318    5.  Added support for \N, which always matches any character other than
319        newline. (It is the same as "." when PCRE_DOTALL is not set.)
321    6.  When compiling pcregrep with newer versions of gcc which may have
322        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
323        declared with attribute warn_unused_result" were given. Just casting the
324        result to (void) does not stop the warnings; a more elaborate fudge is
325        needed. I've used a macro to implement this.
327    7.  Minor change to pcretest.c to avoid a compiler warning.
329    8.  Added four artifical Unicode properties to help with an option to make
330        \s etc use properties (see next item). The new properties are: Xan
331        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
333    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
334        use Unicode properties. (*UCP) at the start of a pattern can be used to set
335        this option. Modified pcretest to add /W to test this facility. Added
336        REG_UCP to make it available via the POSIX interface.
338    10. Added --line-buffered to pcregrep.
340    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
341        studied, and the match started with a letter with a code point greater than
342        127 whose first byte was different to the first byte of the other case of
343        the letter, the other case of this starting letter was not recognized
344        (#976).
346    12. If a pattern that was studied started with a repeated Unicode property
347        test, for example, \p{Nd}+, there was the theoretical possibility of
348        setting up an incorrect bitmap of starting bytes, but fortunately it could
349        not have actually happened in practice until change 8 above was made (it
350        added property types that matched character-matching opcodes).
352    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
353        possible starting bytes for non-anchored patterns.
355    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
356        \R, and also a number of cases that involve Unicode properties, both
357        explicit and implicit when PCRE_UCP is set.
359    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
360        input, it could crash or give wrong results if characters with values
361        greater than 0xc0 were present in the subject string. (Detail: it assumed
362        UTF-8 input when processing these items.)
364    16. Added a lot of (int) casts to avoid compiler warnings in systems where
365        size_t is 64-bit (#991).
367    17. Added a check for running out of memory when PCRE is compiled with
368        --disable-stack-for-recursion (#990).
370    18. If the last data line in a file for pcretest does not have a newline on
371        the end, a newline was missing in the output.
373    19. The default pcre_chartables.c file recognizes only ASCII characters (values
374        less than 128) in its various bitmaps. However, there is a facility for
375        generating tables according to the current locale when PCRE is compiled. It
376        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
377        characters, are recognized by isspace() and therefore were getting set in
378        these tables, and indeed these tables seem to approximate to ISO 8859. This
379        caused a problem in UTF-8 mode when pcre_study() was used to create a list
380        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
381        which of course cannot start UTF-8 characters. I have changed the code so
382        that only real ASCII characters (less than 128) and the correct starting
383        bytes for UTF-8 encodings are set for characters greater than 127 when in
384        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
385        altogether.)
387    20. Added the /T option to pcretest so as to be able to run tests with non-
388        standard character tables, thus making it possible to include the tests
389        used for 19 above in the standard set of tests.
391    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
392        reference to a subpattern the other side of a comment that contains an
393        opening parenthesis caused either an internal compiling error, or a
394        reference to the wrong subpattern.
397    Version 8.02 19-Mar-2010
398    ------------------------
400    1.  The Unicode data tables have been updated to Unicode 5.2.0.
402    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
403        configured.
405    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
406        original author of that file, following a query about its status.
408    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
409        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
411    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
412        quantifier applied to a forward-referencing subroutine call, could compile
413        incorrect code or give the error "internal error: previously-checked
414        referenced subpattern not found".
416    6.  Both MS Visual Studio and Symbian OS have problems with initializing
417        variables to point to external functions. For these systems, therefore,
418        pcre_malloc etc. are now initialized to local functions that call the
419        relevant global functions.
421    7.  There were two entries missing in the vectors called coptable and poptable
422        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
423        I've fixed the data, and added a kludgy way of testing at compile time that
424        the lengths are correct (equal to the number of opcodes).
426    8.  Following on from 7, I added a similar kludge to check the length of the
427        eint vector in pcreposix.c.
429    9.  Error texts for pcre_compile() are held as one long string to avoid too
430        much relocation at load time. To find a text, the string is searched,
431        counting zeros. There was no check for running off the end of the string,
432        which could happen if a new error number was added without updating the
433        string.
435    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
437    11. \K was not working if it appeared in an atomic group or in a group that
438        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
439        \K is "not well defined" if used in an assertion. PCRE now accepts it if
440        the assertion is positive, but not if it is negative.
442    12. Change 11 fortuitously reduced the size of the stack frame used in the
443        "match()" function of pcre_exec.c by one pointer. Forthcoming
444        implementation of support for (*MARK) will need an extra pointer on the
445        stack; I have reserved it now, so that the stack frame size does not
446        decrease.
448    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
449        item in branch that calls a recursion is a subroutine call - as in the
450        second branch in the above example - was incorrectly given the compile-
451        time error "recursive call could loop indefinitely" because pcre_compile()
452        was not correctly checking the subroutine for matching a non-empty string.
454    14. The checks for overrunning compiling workspace could trigger after an
455        overrun had occurred. This is a "should never occur" error, but it can be
456        triggered by pathological patterns such as hundreds of nested parentheses.
457        The checks now trigger 100 bytes before the end of the workspace.
459    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
462    Version 8.01 19-Jan-2010
463    ------------------------
465    1.  If a pattern contained a conditional subpattern with only one branch (in
466        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
467        computed the wrong minimum data length (which is of course zero for such
468        subpatterns). This could cause incorrect "no match" results.
470    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
471        the pattern is reset in the first branch, pcre_compile() failed with
472        "internal error: code overflow at offset...". This happened only when
473        the reset was to the original external option setting. (An optimization
474        abstracts leading options settings into an external setting, which was the
475        cause of this.)
477    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
478        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
479        assertion pattern did not match (meaning that the assertion was true), it
480        was incorrectly treated as false if the SKIP had been reached during the
481        matching. This also applied to assertions used as conditions.
483    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
484        assertion subpattern, including such a pattern used as a condition,
485        unpredictable results occurred, instead of the error return
488    5.  The C++ GlobalReplace function was not working like Perl for the special
489        situation when an empty string is matched. It now does the fancy magic
490        stuff that is necessary.
492    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
493        removed. (These were left over from very, very early versions of PCRE.)
495    7.  Some cosmetic changes to the code to make life easier when compiling it
496        as part of something else:
498        (a) Change DEBUG to PCRE_DEBUG.
500        (b) In pcre_compile(), rename the member of the "branch_chain" structure
501            called "current" as "current_branch", to prevent a collision with the
502            Linux macro when compiled as a kernel module.
504        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
505            prevent a collision with the Linux macro when compiled as a kernel
506            module.
508    8.  In pcre_compile() there are some checks for integer overflows that used to
509        cast potentially large values to (double). This has been changed to that
510        when building, a check for int64_t is made, and if it is found, it is used
511        instead, thus avoiding the use of floating point arithmetic. (There is no
512        other use of FP in PCRE.) If int64_t is not found, the fallback is to
513        double.
515    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
516        2005 (difference between two addresses compared to an unsigned value).
518    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
519        custom one, because of the following reported problem in Windows:
521          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
522              under Win32.
523          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
524              therefore missing the function definition.
525          - The compiler thus generates a "C" signature for the test function.
526          - The linker fails to find the "C" function.
527          - PCRE fails to configure if asked to do so against libbz2.
529    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
530        messages were output:
532          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
533          rerunning libtoolize, to keep the correct libtool macros in-tree.
534          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
536        I have done both of these things.
538    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
539        most of the time, it *can* run out if it is given a pattern that contains a
540        runaway infinite recursion. I updated the discussion in the pcrestack man
541        page.
543    13. Now that we have gone to the x.xx style of version numbers, the minor
544        version may start with zero. Using 08 or 09 is a bad idea because users
545        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
546        interpreted as invalid octal numbers. I've updated the previous comment in
547        configure.ac, and also added a check that gives an error if 08 or 09 are
548        used.
550    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
551        causing partial matching to fail when the end of the subject matched \W
552        in a UTF-8 pattern where \W was quantified with a minimum of 3.
554    15. There were some discrepancies between the declarations in pcre_internal.h
555        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
556        their definitions. The declarations used "const uschar *" and the
557        definitions used USPTR. Even though USPTR is normally defined as "const
558        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
559        reported that: "This difference in casting confuses some C++ compilers, for
560        example, SunCC recognizes above declarations as different functions and
561        generates broken code for hbpcre." I have changed the declarations to use
562        USPTR.
564    16. GNU libtool is named differently on some systems. The autogen.sh script now
565        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
566        (FreeBSD).
568    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
569        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
570        comment: "Figure out how to create a longlong from a string: strtoll and
571        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
572        instance, but it only takes 2 args instead of 3!"
574    18. A subtle bug concerned with back references has been fixed by a change of
575        specification, with a corresponding code fix. A pattern such as
576        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
577        refers, was giving matches when it shouldn't. For example, xa=xaaa would
578        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
579        same bug. Such groups have to be quantified to be useful, or contained
580        inside another quantified group. (If there's no repetition, the reference
581        can never match.) The problem arises because, having left the group and
582        moved on to the rest of the pattern, a later failure that backtracks into
583        the group uses the captured value from the final iteration of the group
584        rather than the correct earlier one. I have fixed this in PCRE by forcing
585        any group that contains a reference to itself to be an atomic group; that
586        is, there cannot be any backtracking into it once it has completed. This is
587        similar to recursive and subroutine calls.
590    Version 8.00 19-Oct-09
591    ----------------------
593    1.  The table for translating pcre_compile() error codes into POSIX error codes
594        was out-of-date, and there was no check on the pcre_compile() error code
595        being within the table. This could lead to an OK return being given in
596        error.
598    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
599        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
600        in a Windows environment.
602    3.  The pcregrep --count option prints the count for each file even when it is
603        zero, as does GNU grep. However, pcregrep was also printing all files when
604        --files-with-matches was added. Now, when both options are given, it prints
605        counts only for those files that have at least one match. (GNU grep just
606        prints the file name in this circumstance, but including the count seems
607        more useful - otherwise, why use --count?) Also ensured that the
608        combination -clh just lists non-zero counts, with no names.
610    4.  The long form of the pcregrep -F option was incorrectly implemented as
611        --fixed_strings instead of --fixed-strings. This is an incompatible change,
612        but it seems right to fix it, and I didn't think it was worth preserving
613        the old behaviour.
615    5.  The command line items --regex=pattern and --regexp=pattern were not
616        recognized by pcregrep, which required --regex pattern or --regexp pattern
617        (with a space rather than an '='). The man page documented the '=' forms,
618        which are compatible with GNU grep; these now work.
620    6.  No libpcreposix.pc file was created for pkg-config; there was just
621        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
623    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
624        when UCP support is not needed, by modifying the Python script that
625        generates it from Unicode data files. This should not matter if the module
626        is correctly used as a library, but I received one complaint about 50K of
627        unwanted data. My guess is that the person linked everything into his
628        program rather than using a library. Anyway, it does no harm.
630    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
631        was a minimum greater than 1 for a wide character in a possessive
632        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
633        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
634        character. Chaos in the form of incorrect output or a compiling loop could
635        result.
637    9.  The restrictions on what a pattern can contain when partial matching is
638        requested for pcre_exec() have been removed. All patterns can now be
639        partially matched by this function. In addition, if there are at least two
640        slots in the offset vector, the offset of the earliest inspected character
641        for the match and the offset of the end of the subject are set in them when
642        PCRE_ERROR_PARTIAL is returned.
644    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
645        synonymous with PCRE_PARTIAL, for backwards compatibility, and
646        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
647        and may be more useful for multi-segment matching.
649    11. Partial matching with pcre_exec() is now more intuitive. A partial match
650        used to be given if ever the end of the subject was reached; now it is
651        given only if matching could not proceed because another character was
652        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
653        string "Z", which now yields "no match" instead of "partial match". In the
654        case of pcre_dfa_exec(), "no match" is given if every matching path for the
655        final character ended with (*FAIL).
657    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
658        if the pattern had a "must contain" character that was already found in the
659        earlier partial match, unless partial matching was again requested. For
660        example, with the pattern /dog.(body)?/, the "must contain" character is
661        "g". If the first part-match was for the string "dog", restarting with
662        "sbody" failed. This bug has been fixed.
664    13. The string returned by pcre_dfa_exec() after a partial match has been
665        changed so that it starts at the first inspected character rather than the
666        first character of the match. This makes a difference only if the pattern
667        starts with a lookbehind assertion or \b or \B (\K is not supported by
668        pcre_dfa_exec()). It's an incompatible change, but it makes the two
669        matching functions compatible, and I think it's the right thing to do.
671    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
672        so that the demonstration program is easily available in environments where
673        PCRE has not been installed from source.
675    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
676        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
677        library.
679    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
680        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
681        is not the first non-POSIX option to be added. Clearly some people find
682        these options useful.
684    17. If a caller to the POSIX matching function regexec() passes a non-zero
685        value for nmatch with a NULL value for pmatch, the value of
686        nmatch is forced to zero.
688    18. RunGrepTest did not have a test for the availability of the -u option of
689        the diff command, as RunTest does. It now checks in the same way as
690        RunTest, and also checks for the -b option.
692    19. If an odd number of negated classes containing just a single character
693        interposed, within parentheses, between a forward reference to a named
694        subpattern and the definition of the subpattern, compilation crashed with
695        an internal error, complaining that it could not find the referenced
696        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
697        [The bug was that it was starting one character too far in when skipping
698        over the character class, thus treating the ] as data rather than
699        terminating the class. This meant it could skip too much.]
701    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
702        /g option in pcretest when the pattern contains \K, which makes it possible
703        to have an empty string match not at the start, even when the pattern is
704        anchored. Updated pcretest and pcredemo to use this option.
706    21. If the maximum number of capturing subpatterns in a recursion was greater
707        than the maximum at the outer level, the higher number was returned, but
708        with unset values at the outer level. The correct (outer level) value is
709        now given.
711    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
712        PCRE did not set those parentheses (unlike Perl). I have now found a way to
713        make it do so. The string so far is captured, making this feature
714        compatible with Perl.
716    23. The tests have been re-organized, adding tests 11 and 12, to make it
717        possible to check the Perl 5.10 features against Perl 5.10.
719    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
720        pattern matches a fixed length string. PCRE did not allow this; now it
721        does. Neither allows recursion.
723    25. I finally figured out how to implement a request to provide the minimum
724        length of subject string that was needed in order to match a given pattern.
725        (It was back references and recursion that I had previously got hung up
726        on.) This code has now been added to pcre_study(); it finds a lower bound
727        to the length of subject needed. It is not necessarily the greatest lower
728        bound, but using it to avoid searching strings that are too short does give
729        some useful speed-ups. The value is available to calling programs via
730        pcre_fullinfo().
732    26. While implementing 25, I discovered to my embarrassment that pcretest had
733        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
734        study optimizations had never been tested with that matching function.
735        Oops. What is worse, even when it was passed study data, there was a bug in
736        pcre_dfa_exec() that meant it never actually used it. Double oops. There
737        were also very few tests of studied patterns with pcre_dfa_exec().
739    27. If (?| is used to create subpatterns with duplicate numbers, they are now
740        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
741        on the other side of the coin, they are no longer allowed to have different
742        names, because these cannot be distinguished in PCRE, and this has caused
743        confusion. (This is a difference from Perl.)
745    28. When duplicate subpattern names are present (necessarily with different
746        numbers, as required by 27 above), and a test is made by name in a
747        conditional pattern, either for a subpattern having been matched, or for
748        recursion in such a pattern, all the associated numbered subpatterns are
749        tested, and the overall condition is true if the condition is true for any
750        one of them. This is the way Perl works, and is also more like the way
751        testing by number works.
754    Version 7.9 11-Apr-09
755    ---------------------
757    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
758        (pcretest), all targets were linked against these libraries. This included
759        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
760        libraries. This caused unwanted dependencies to be created. This problem
761        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
762        pcretest is linked with readline.
764    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
765        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
766        moved outside it again, because FALSE and TRUE are already defined in AIX,
767        but BOOL is not.
769    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
770        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
772    4.  The pcregrep documentation said spaces were inserted as well as colons (or
773        hyphens) following file names and line numbers when outputting matching
774        lines. This is not true; no spaces are inserted. I have also clarified the
775        wording for the --colour (or --color) option.
777    5.  In pcregrep, when --colour was used with -o, the list of matching strings
778        was not coloured; this is different to GNU grep, so I have changed it to be
779        the same.
781    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
782        each matching line was coloured. Now it goes on to look for further matches
783        of any of the test patterns, which is the same behaviour as GNU grep.
785    7.  A pattern that could match an empty string could cause pcregrep to loop; it
786        doesn't make sense to accept an empty string match in pcregrep, so I have
787        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
788        seems to be how GNU grep behaves.
790    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
791        start or after a newline", because the conditional assertion was not being
792        correctly handled. The rule now is that both the assertion and what follows
793        in the first alternative must satisfy the test.
795    9.  If auto-callout was enabled in a pattern with a conditional group whose
796        condition was an assertion, PCRE could crash during matching, both with
797        pcre_exec() and pcre_dfa_exec().
799    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
800        used for matching.
802    11. Unicode property support in character classes was not working for
803        characters (bytes) greater than 127 when not in UTF-8 mode.
805    12. Added the -M command line option to pcretest.
807    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
809    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
811    16. Added comments and documentation about mis-use of no_arg in the C++
812        wrapper.
814    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
815        from Martin Jerabek that uses macro names for all relevant character and
816        string constants.
818    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
819        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
820        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
821        these, but not everybody uses configure.
823    19. A conditional group that had only one branch was not being correctly
824        recognized as an item that could match an empty string. This meant that an
825        enclosing group might also not be so recognized, causing infinite looping
826        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
827        with the subject "ab", where knowledge that the repeated group can match
828        nothing is needed in order to break the loop.
830    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
831        exec(), but without supplying a callout function, matching went wrong.
833    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
834        leak if the size of the offset vector was greater than 30. When the vector
835        is smaller, the saved offsets during recursion go onto a local stack
836        vector, but for larger vectors malloc() is used. It was failing to free
837        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
838        error, in fact).
840    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
841        heapframe that is used only when UTF-8 support is enabled. This caused no
842        problem, but was untidy.
844    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
845        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
846        included within another project.
848    24. Steven Van Ingelgem's patches to add more options to the CMake support,
849        slightly modified by me:
851          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
852              not building pcregrep.
854          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
855              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
857    25. Forward references, both numeric and by name, in patterns that made use of
858        duplicate group numbers, could behave incorrectly or give incorrect errors,
859        because when scanning forward to find the reference group, PCRE was not
860        taking into account the duplicate group numbers. A pattern such as
861        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
863    26. Changed a few more instances of "const unsigned char *" to USPTR, making
864        the feature of a custom pointer more persuasive (as requested by a user).
866    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
867        pcretest.c, inside #ifndefs, because it seems they are sometimes already
868        pre-defined.
870    28. Added support for (*UTF8) at the start of a pattern.
872    29. Arrange for flags added by the "release type" setting in CMake to be shown
873        in the configuration summary.
876    Version 7.8 05-Sep-08
877    ---------------------
879    1.  Replaced UCP searching code with optimized version as implemented for Ad
880        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
881        stage table and inline lookup instead of a function, giving speed ups of 2
882        to 5 times on some simple patterns that I tested. Permission was given to
883        distribute the MultiStage2.py script that generates the tables (it's not in
884        the tarball, but is in the Subversion repository).
886    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
887        scripts.
889    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
890        a group with a zero qualifier. The result of the study could be incorrect,
891        or the function might crash, depending on the pattern.
893    4.  Caseless matching was not working for non-ASCII characters in back
894        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
895        It now works when Unicode Property Support is available.
897    5.  In pcretest, an escape such as \x{de} in the data was always generating
898        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
899        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
900        truncation.
902    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
904    7.  Added two (int) casts to pcregrep when printing the difference of two
905        pointers, in case they are 64-bit values.
907    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
908        test 2 if it fails.
910    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
911        and a #define of that name to empty if it is not externally set. This is to
912        allow users of MSVC to set it if necessary.
914    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
915        the convenience functions in the pcre_get.c source file.
917    11. An option change at the start of a pattern that had top-level alternatives
918        could cause overwriting and/or a crash. This command provoked a crash in
919        some environments:
921          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
923        This potential security problem was recorded as CVE-2008-2371.
925    12. For a pattern where the match had to start at the beginning or immediately
926        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
927        pcre_dfa_exec() could read past the end of the passed subject if there was
928        no match. To help with detecting such bugs (e.g. with valgrind), I modified
929        pcretest so that it places the subject at the end of its malloc-ed buffer.
931    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
932        exec() might read past the end of the data buffer in UTF-8 mode.
934    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
935        the data contained the byte 0x85 as part of a UTF-8 character within its
936        first line. This applied both to normal and DFA matching.
938    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
939        /^[^d]*?$/8 failed to match "abc".
941    16. Added a missing copyright notice to pcrecpp_internal.h.
943    17. Make it more clear in the documentation that values returned from
944        pcre_exec() in ovector are byte offsets, not character counts.
946    18. Tidied a few places to stop certain compilers from issuing warnings.
948    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
949        supplied by Stefan Weber. I made a further small update for 7.8 because
950        there is a change of source arrangements: the pcre_searchfuncs.c module is
951        replaced by pcre_ucd.c.
954    Version 7.7 07-May-08
955    ---------------------
957    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
958        a string to a long long, pretend we don't even have a long long." This is
959        done by checking for the strtoq, strtoll, and _strtoi64 functions.
961    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
962        pre-7.6 versions, which defined a global no_arg variable instead of putting
963        it in the RE class. (See also #8 below.)
965    3.  Remove a line of dead code, identified by coverity and reported by Nuno
966        Lopes.
968    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
970        (1) The include/exclude patterns were being applied to the whole pathnames
971            of files, instead of just to the final components.
973        (2) If there was more than one level of directory, the subdirectories were
974            skipped unless they satisfied the include/exclude conditions. This is
975            inconsistent with GNU grep (and could even be seen as contrary to the
976            pcregrep specification - which I improved to make it absolutely clear).
977            The action now is always to scan all levels of directory, and just
978            apply the include/exclude patterns to regular files.
980    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
981        --exclude_dir in the tests to avoid scanning .svn directories.
983    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
984        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
985        doesn't support NULs in patterns.
987    7.  Added some missing "const"s to declarations of static tables in
988        pcre_compile.c and pcre_dfa_exec.c.
990    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
991        caused by fix #2  above. (Subsequently also a second patch to fix the
992        first patch. And a third patch - this was a messy problem.)
994    9.  Applied Craig's patch to remove the use of push_back().
996    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
997        matching function regexec().
999    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1000        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1001        references. PCRE supports relative numbers with this syntax (I don't think
1002        Oniguruma does).
1004    12. Previously, a group with a zero repeat such as (...){0} was completely
1005        omitted from the compiled regex. However, this means that if the group
1006        was called as a subroutine from elsewhere in the pattern, things went wrong
1007        (an internal error was given). Such groups are now left in the compiled
1008        pattern, with a new opcode that causes them to be skipped at execution
1009        time.
1011    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1012        to the way PCRE behaves:
1014        (a) A lone ] character is dis-allowed (Perl treats it as data).
1016        (b) A back reference to an unmatched subpattern matches an empty string
1017            (Perl fails the current match path).
1019        (c) A data ] in a character class must be notated as \] because if the
1020            first data character in a class is ], it defines an empty class. (In
1021            Perl it is not possible to have an empty class.) The empty class []
1022            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1023            The negative empty class [^] matches any one character, independently
1024            of the DOTALL setting.
1026    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1027        non-existent subpattern following a character class starting with ']' and
1028        containing () gave an internal compiling error instead of "reference to
1029        non-existent subpattern". Fortunately, when the pattern did exist, the
1030        compiled code was correct. (When scanning forwards to check for the
1031        existencd of the subpattern, it was treating the data ']' as terminating
1032        the class, so got the count wrong. When actually compiling, the reference
1033        was subsequently set up correctly.)
1035    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1036        it was being rejected as not supported by pcre_dfa_exec(), even though
1037        other assertions are supported. I have made pcre_dfa_exec() support
1038        (*FAIL).
1040    16. The implementation of 13c above involved the invention of a new opcode,
1041        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1042        cannot be changed at match time, I realized I could make a small
1043        improvement to matching performance by compiling OP_ALLANY instead of
1044        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1045        on the OP_ANY path.
1047    17. Compiling pcretest on Windows with readline support failed without the
1048        following two fixes: (1) Make the unistd.h include conditional on
1049        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1051    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1052        ncurses library to be included for pcretest when ReadLine support is
1053        requested, but also to allow for it to be overridden. This patch came from
1054        Daniel Bergström.
1056    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1057        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1058        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1059        spotting this.
1062    Version 7.6 28-Jan-08
1063    ---------------------
1065    1.  A character class containing a very large number of characters with
1066        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1067        overflow.
1069    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1070        HAVE_LONG_LONG is not defined.
1072    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1073        bring them up to date and include new features. This patch includes:
1075        - Fixed PH's badly added libz and libbz2 support.
1076        - Fixed a problem with static linking.
1077        - Added pcredemo. [But later removed - see 7 below.]
1078        - Fixed dftables problem and added an option.
1079        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1080            HAVE_LONG_LONG.
1081        - Added readline support for pcretest.
1082        - Added an listing of the option settings after cmake has run.
1084    4.  A user submitted a patch to Makefile that makes it easy to create
1085        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1086        Makefile.am that cause it to include this special target, without
1087        affecting anything else. Note that the same mingw target plus all
1088        the other distribution libraries and programs are now supported
1089        when configuring with CMake (see 6 below) instead of with
1090        Configure/Make.
1092    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1093        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1094        exported in the Windows port". It has not yet been confirmed that the patch
1095        solves the problem, but it does no harm.
1097    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1098        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1099        with CMake, and also correct the comment about stack recursion.
1101    7.  Remove the automatic building of pcredemo from the ./configure system and
1102        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1103        of a program that users should build themselves after PCRE is installed, so
1104        building it automatically is not really right. What is more, it gave
1105        trouble in some build environments.
1107    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1110    Version 7.5 10-Jan-08
1111    ---------------------
1113    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1114        values in parens when parsing an RE using the C++ wrapper."
1116    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1117        Characters greater than 255 were excluded from the class instead of being
1118        included.
1120    3.  The same bug as (2) above applied to negated POSIX classes such as
1121        [:^space:].
1123    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1124        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1125        I have changed it.
1127    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1128        first named subpattern) and a construct such as (?&a) would reference the
1129        first named subpattern whose name started with "a" (in other words, the
1130        length check was missing). Both these problems are fixed. "Subpattern name
1131        expected" is now given for (?&) (a zero-length name), and this patch also
1132        makes it give the same error for \k'' (previously it complained that that
1133        was a reference to a non-existent subpattern).
1135    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1136        this is right because (?- can be followed by option settings as well as by
1137        digits. I have, however, made the messages clearer.
1139    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1140        than the number used in the conditional) now cause a compile-time error.
1141        This is actually not compatible with Perl, which accepts such patterns, but
1142        treats the conditional as always being FALSE (as PCRE used to), but it
1143        seems to me that giving a diagnostic is better.
1145    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1146        and messages.
1148    9.  Fix two occurrences of "backslash" in comments that should have been
1149        "backspace".
1151    10. Remove two redundant lines of code that can never be obeyed (their function
1152        was moved elsewhere).
1154    11. The program that makes PCRE's Unicode character property table had a bug
1155        which caused it to generate incorrect table entries for sequences of
1156        characters that have the same character type, but are in different scripts.
1157        It amalgamated them into a single range, with the script of the first of
1158        them. In other words, some characters were in the wrong script. There were
1159        thirteen such cases, affecting characters in the following ranges:
1161          U+002b0 - U+002c1
1162          U+0060c - U+0060d
1163          U+0061e - U+00612
1164          U+0064b - U+0065e
1165          U+0074d - U+0076d
1166          U+01800 - U+01805
1167          U+01d00 - U+01d77
1168          U+01d9b - U+01dbf
1169          U+0200b - U+0200f
1170          U+030fc - U+030fe
1171          U+03260 - U+0327f
1172          U+0fb46 - U+0fbb1
1173          U+10450 - U+1049d
1175    12. The -o option (show only the matching part of a line) for pcregrep was not
1176        compatible with GNU grep in that, if there was more than one match in a
1177        line, it showed only the first of them. It now behaves in the same way as
1178        GNU grep.
1180    13. If the -o and -v options were combined for pcregrep, it printed a blank
1181        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1182        does the same. The return code can be used to tell if there were any
1183        non-matching lines.
1185    14. Added --file-offsets and --line-offsets to pcregrep.
1187    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1188        infinitely looping recursion. The bug was that positive lookaheads were not
1189        being skipped when checking for a possible empty match (negative lookaheads
1190        and both kinds of lookbehind were skipped).
1192    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1193        inclusion of <windows.h> to before rather than after the definition of
1194        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1196    17. Specifying a possessive quantifier with a specific limit for a Unicode
1197        character property caused pcre_compile() to compile bad code, which led at
1198        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1199        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1200        caused the error; without that there was no problem.
1202    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1204    19. Added --enable-pcretest-libreadline.
1206    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1207        RE::GlobalReplace(). As a result, the number of replacements returned was
1208        double what it should be. I removed one of the increments, but Craig sent a
1209        later patch that removed the other one (the right fix) and added unit tests
1210        that check the return values (which was not done before).
1212    21. Several CMake things:
1214        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1215            the names libpcre and libpcreposix, not just pcre and pcreposix.
1217        (2) The above change means that pcretest and pcregrep are now correctly
1218            linked with the newly-built libraries, not previously installed ones.
1222    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1223        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1224        UTF-8 newline character). The key issue is that the pattern starts .*;
1225        this means that the match must be either at the beginning, or after a
1226        newline. The bug was in the code for advancing after a failed match and
1227        checking that the new position followed a newline. It was not taking
1228        account of UTF-8 characters correctly.
1230    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1231        character classes. PCRE was not treating the sequence [:...:] as a
1232        character class unless the ... were all letters. Perl, however, seems to
1233        allow any characters between [: and :], though of course it rejects as
1234        unknown any "names" that contain non-letters, because all the known class
1235        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1236        for example, whereas PCRE did not - it did not recognize a POSIX character
1237        class. This seemed a bit dangerous, so the code has been changed to be
1238        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1239        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1240        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1241        Perl does, and where it didn't before.
1243    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1244        Windows environments %n is disabled by default.
1247    Version 7.4 21-Sep-07
1248    ---------------------
1250    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1251        means that a class such as [\s] counted as "explicit reference to CR or
1252        LF". That isn't really right - the whole point of the change was to try to
1253        help when there was an actual mention of one of the two characters. So now
1254        the change happens only if \r or \n (or a literal CR or LF) character is
1255        encountered.
1257    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1258        of both had grown to the point where there were only 3 bits left.
1259        Fortunately, there was spare space in the data structure, and so I have
1260        moved the internal flags into a new 16-bit field to free up more option
1261        bits.
1263    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1264        but did not set the internal JCHANGED flag - either of these is enough to
1265        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1266        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1267        start sets both bits.
1269    4.  Added options (at build time, compile time, exec time) to change \R from
1270        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1272    5.  doc/pcresyntax.html was missing from the distribution.
1274    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1275        compatibility, even though it is no longer used.
1277    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1278        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1279        windows.h file is present (where different names are used). [This was
1280        reversed later after testing - see 16 below.]
1282    8.  Changed all #include <config.h> to #include "config.h". There were also
1283        some further <pcre.h> cases that I changed to "pcre.h".
1285    9.  When pcregrep was used with the --colour option, it missed the line ending
1286        sequence off the lines that it output.
1288    10. It was pointed out to me that arrays of string pointers cause lots of
1289        relocations when a shared library is dynamically loaded. A technique of
1290        using a single long string with a table of offsets can drastically reduce
1291        these. I have refactored PCRE in four places to do this. The result is
1292        dramatic:
1294          Originally:                          290
1295          After changing UCP table:            187
1296          After changing error message table:   43
1297          After changing table of "verbs"       36
1298          After changing table of Posix names   22
1300        Thanks to the folks working on Gregex for glib for this insight.
1302    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1303        unicode-properties was also set.
1305    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1307    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1308        checked only for CRLF.
1310    14. Added casts to pcretest.c to avoid compiler warnings.
1312    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1314    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1315        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1316        entirely. This removes changes made in 7 above.
1318    17. The CMake files have been updated, and there is now more information about
1319        building with CMake in the NON-UNIX-USE document.
1322    Version 7.3 28-Aug-07
1323    ---------------------
1325     1. In the rejigging of the build system that eventually resulted in 7.1, the
1326        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1327        brackets there is not right, since it causes compilers to look for an
1328        installed pcre.h, not the version that is in the source that is being
1329        compiled (which of course may be different). I have changed it back to:
1331          #include "pcre.h"
1333        I have a vague recollection that the change was concerned with compiling in
1334        different directories, but in the new build system, that is taken care of
1335        by the VPATH setting the Makefile.
1337     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1338        when the subject happened to end in the byte 0x85 (e.g. if the last
1339        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1340        characters but of course it shouldn't be taken as a newline when it is part
1341        of another character. The bug was that, for an unlimited repeat of . in
1342        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1343        characters when looking for a newline.
1345     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1347     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1348        in debug output.
1350     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1351        long printing in the pcrecpp unittest when running under MinGW.
1353     6. ESC_K was left out of the EBCDIC table.
1355     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1356        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1357        limit also applies to "virtual nesting" when a pattern is recursive, and in
1358        this case 1000 isn't so big. I have been able to remove this limit at the
1359        expense of backing off one optimization in certain circumstances. Normally,
1360        when pcre_exec() would call its internal match() function recursively and
1361        immediately return the result unconditionally, it uses a "tail recursion"
1362        feature to save stack. However, when a subpattern that can match an empty
1363        string has an unlimited repetition quantifier, it no longer makes this
1364        optimization. That gives it a stack frame in which to save the data for
1365        checking that an empty string has been matched. Previously this was taken
1366        from the 1000-entry workspace that had been reserved. So now there is no
1367        explicit limit, but more stack is used.
1369     8. Applied Daniel's patches to solve problems with the import/export magic
1370        syntax that is required for Windows, and which was going wrong for the
1371        pcreposix and pcrecpp parts of the library. These were overlooked when this
1372        problem was solved for the main library.
1374     9. There were some crude static tests to avoid integer overflow when computing
1375        the size of patterns that contain repeated groups with explicit upper
1376        limits. As the maximum quantifier is 65535, the maximum group length was
1377        set at 30,000 so that the product of these two numbers did not overflow a
1378        32-bit integer. However, it turns out that people want to use groups that
1379        are longer than 30,000 bytes (though not repeat them that many times).
1380        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1381        made it possible to implement the integer overflow checks in a much more
1382        dynamic way, which I have now done. The artificial limitation on group
1383        length has been removed - we now have only the limit on the total length of
1384        the compiled pattern, which depends on the LINK_SIZE setting.
1386    10. Fixed a bug in the documentation for get/copy named substring when
1387        duplicate names are permitted. If none of the named substrings are set, the
1388        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1389        empty string.
1391    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1392        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1393        because the ] is interpreted as the first data character and the
1394        terminating ] is not found. PCRE has been made compatible with Perl in this
1395        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1396        cause memory overwriting.
1398    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1399        string has been matched (to stop an infinite loop). It was not recognizing
1400        a conditional subpattern that could match an empty string if that
1401        subpattern was within another subpattern. For example, it looped when
1402        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1403        condition was not nested. This bug has been fixed.
1405    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1406        past the start of the subject in the presence of bytes with the top bit
1407        set, for example "\x8aBCD".
1409    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1410        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1412    14. Optimized (?!) to (*FAIL).
1414    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1415        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1416        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1417        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1418        does: it's just the validity check that is more restrictive.
1420    16. Inserted checks for integer overflows during escape sequence (backslash)
1421        processing, and also fixed erroneous offset values for syntax errors during
1422        backslash processing.
1424    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1425        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1427    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1428        caused an overrun.
1430    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1431        something other than just ASCII characters) inside a group that had an
1432        unlimited repeat caused a loop at compile time (while checking to see
1433        whether the group could match an empty string).
1435    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1436        [\P{Any}] did so. (Error in the code for printing property names.)
1438    21. An orphan \E inside a character class could cause a crash.
1440    22. A repeated capturing bracket such as (A)? could cause a wild memory
1441        reference during compilation.
1443    23. There are several functions in pcre_compile() that scan along a compiled
1444        expression for various reasons (e.g. to see if it's fixed length for look
1445        behind). There were bugs in these functions when a repeated \p or \P was
1446        present in the pattern. These operators have additional parameters compared
1447        with \d, etc, and these were not being taken into account when moving along
1448        the compiled data. Specifically:
1450        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1451            length.
1453        (b) An item such as \pL+ within a repeated group could cause crashes or
1454            loops.
1456        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1457            "reference to non-existent subpattern" error.
1459        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1461    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1462        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1464    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1466    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1467        character were causing crashes (broken optimization).
1469    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1470        \p or \P) caused a compile-time loop.
1472    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1473        break. For example, the unstudied pattern [\r\n]A does not match the string
1474        "\r\nA" because change 7.0/46 below moves the current point on by two
1475        characters after failing to match at the start. However, the pattern \nA
1476        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1477        the same is true. There doesn't seem any very clean way out of this, but
1478        what I have chosen to do makes the common cases work: PCRE now takes note
1479        of whether there can be an explicit match for \r or \n anywhere in the
1480        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1481        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1482        pattern has explicit CR or LF references.
1484    29. Added (*CR) etc for changing newline setting at start of pattern.
1487    Version 7.2 19-Jun-07
1488    ---------------------
1490     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1491        which is apparently normally available under Windows.
1493     2. Re-jig the pcregrep tests with different newline settings in an attempt
1494        to make them independent of the local environment's newline setting.
1496     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1498     4. Some of the "internals" tests were previously cut out when the link size
1499        was not 2, because the output contained actual offsets. The recent new
1500        "Z" feature of pcretest means that these can be cut out, making the tests
1501        usable with all link sizes.
1503     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1504        stack recursion. This gives a massive performance boost under BSD, but just
1505        a small improvement under Linux. However, it saves one field in the frame
1506        in all cases.
1508     6. Added more features from the forthcoming Perl 5.10:
1510        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1511            recursion call. It refers to the nth most recently opened parentheses.
1513        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1514            to be opened parentheses.
1516        (c) Conditions that refer to capturing parentheses can be specified
1517            relatively, for example, (?(-2)... or (?(+3)...
1519        (d) \K resets the start of the current match so that everything before
1520            is not part of it.
1522        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1524        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1525            reference syntax.
1527        (g) (?| introduces a group in which the numbering of parentheses in each
1528            alternative starts with the same number.
1530        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1532     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1535     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1536        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1537        for detecting groups that can match an empty string.
1539     9. A pattern with a very large number of alternatives (more than several
1540        hundred) was running out of internal workspace during the pre-compile
1541        phase, where pcre_compile() figures out how much memory will be needed. A
1542        bit of new cunning has reduced the workspace needed for groups with
1543        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1544        workspace instead of running out of the 4096 that are available.
1546    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1548    11. Applied patch from Google to remove an optimization that didn't quite work.
1549        The report of the bug said:
1551          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1552          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1553          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1555    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1556        it matched the wrong number of bytes.
1559    Version 7.1 24-Apr-07
1560    ---------------------
1562     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1563        that is more "standard", making use of automake and other Autotools. There
1564        is some re-arrangement of the files and adjustment of comments consequent
1565        on this.
1567     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1568        for recursive directory scanning broke on some systems because the files
1569        are not scanned in any specific order and on different systems the order
1570        was different. A call to "sort" has been inserted into RunGrepTest for the
1571        approprate test as a short-term fix. In the longer term there may be an
1572        alternative.
1574     3. I had an email from Eric Raymond about problems translating some of PCRE's
1575        man pages to HTML (despite the fact that I distribute HTML pages, some
1576        people do their own conversions for various reasons). The problems
1577        concerned the use of low-level troff macros .br and .in. I have therefore
1578        removed all such uses from the man pages (some were redundant, some could
1579        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1580        HTML has been updated to handle .nf/.fi and to complain if it encounters
1581        .br or .in.
1583     4. Updated comments in configure.ac that get placed in config.h.in and also
1584        arranged for config.h to be included in the distribution, with the name
1585        config.h.generic, for the benefit of those who have to compile without
1586        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1588     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1589        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1590        makevp.bat for the current PCRE, using the additional files
1591        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1593     6. A Windows user reported a minor discrepancy with test 2, which turned out
1594        to be caused by a trailing space on an input line that had got lost in his
1595        copy. The trailing space was an accident, so I've just removed it.
1597     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1598        that is needed.
1600     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1601        as "const" (a) because they are and (b) because it helps the PHP
1602        maintainers who have recently made a script to detect big data structures
1603        in the php code that should be moved to the .rodata section. I remembered
1604        to update Builducptable as well, so it won't revert if ucptable.h is ever
1605        re-created.
1607     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1608        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1609        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1610        support is not required. This saves 1.5-2K of code, which is important in
1611        some applications.
1613        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1614        so as not to refer to the tables, even though these functions will never be
1615        called when UTF-8 support is disabled. Otherwise there are problems with a
1616        shared library.
1618    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1620        (a) It was defining its arguments as char * instead of void *.
1622        (b) It was assuming that all moves were upwards in memory; this was true
1623            a long time ago when I wrote it, but is no longer the case.
1625        The emulated memove() is provided for those environments that have neither
1626        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1627        is clearly not the case, as these two bugs were recently reported.
1629    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1630        and Detrail to create the HTML documentation, the .txt form of the man
1631        pages, and it removes trailing spaces from listed files. It also creates
1632        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1633        case, it wraps all the #defines with #ifndefs. This script should be run
1634        before "make dist".
1636    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1637        with Unicode property support.
1639        (a) For a maximizing quantifier, if the two different cases of the
1640            character were of different lengths in their UTF-8 codings (there are
1641            some cases like this - I found 11), and the matching function had to
1642            back up over a mixture of the two cases, it incorrectly assumed they
1643            were both the same length.
1645        (b) When PCRE was configured to use the heap rather than the stack for
1646            recursion during matching, it was not correctly preserving the data for
1647            the other case of a UTF-8 character when checking ahead for a match
1648            while processing a minimizing repeat. If the check also involved
1649            matching a wide character, but failed, corruption could cause an
1650            erroneous result when trying to check for a repeat of the original
1651            character.
1653    13. Some tidying changes to the testing mechanism:
1655        (a) The RunTest script now detects the internal link size and whether there
1656            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1657            values substituted by "configure". (The RunGrepTest script already did
1658            this for UTF-8.) The configure.ac script no longer substitutes the
1659            relevant variables.
1661        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1662            with length and offset values. This means that the output is different
1663            for different internal link sizes. Test 2 is skipped for link sizes
1664            other than 2 because of this, bypassing the problem. Unfortunately,
1665            there was also a test in test 3 (the locale tests) that used /B and
1666            failed for link sizes other than 2. Rather than cut the whole test out,
1667            I have added a new /Z option to pcretest that replaces the length and
1668            offset values with spaces. This is now used to make test 3 independent
1669            of link size. (Test 2 will be tidied up later.)
1671    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1672        segmentation fault instead of returning the appropriate error message.
1674    15. In multiline mode when the newline sequence was set to "any", the pattern
1675        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1676        This doesn't seem right; it now treats the CRLF combination as the line
1677        ending, and so does not match in that case. It's only a pattern such as ^$
1678        that would hit this one: something like ^ABC$ would have failed after \r
1679        and then tried again after \r\n.
1681    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1682        in an attempt to make files that differ only in their line terminators
1683        compare equal. This works on Linux.
1685    17. Under certain error circumstances pcregrep might try to free random memory
1686        as it exited. This is now fixed, thanks to valgrind.
1688    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1689        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1690        was because its rules for how to advance for /g after matching an empty
1691        string at the end of a line did not allow for this case. They now check for
1692        it specially.
1694    20. pcretest is supposed to handle patterns and data of any length, by
1695        extending its buffers when necessary. It was getting this wrong when the
1696        buffer for a data line had to be extended.
1698    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1699        CRLF as a newline sequence.
1701    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1702        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1703        I have nevertheless tidied it up.
1705    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1707    24. Added a man page for pcre-config.
1710    Version 7.0 19-Dec-06
1711    ---------------------
1713     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1714        moving to gcc 4.1.1.
1716     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1717        sys/time.h, which is documented as needed for this function. It doesn't
1718        seem to matter on Linux, but it showed up on some releases of OS X.
1720     3. It seems that there are systems where bytes whose values are greater than
1721        127 match isprint() in the "C" locale. The "C" locale should be the
1722        default when a C program starts up. In most systems, only ASCII printing
1723        characters match isprint(). This difference caused the output from pcretest
1724        to vary, making some of the tests fail. I have changed pcretest so that:
1726        (a) When it is outputting text in the compiled version of a pattern, bytes
1727            other than 32-126 are always shown as hex escapes.
1729        (b) When it is outputting text that is a matched part of a subject string,
1730            it does the same, unless a different locale has been set for the match
1731            (using the /L modifier). In this case, it uses isprint() to decide.
1733     4. Fixed a major bug that caused incorrect computation of the amount of memory
1734        required for a compiled pattern when options that changed within the
1735        pattern affected the logic of the preliminary scan that determines the
1736        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1737        that the computed length was too small. The symptoms of this bug were
1738        either the PCRE error "internal error: code overflow" from pcre_compile(),
1739        or a glibc crash with a message such as "pcretest: free(): invalid next
1740        size (fast)". Examples of patterns that provoked this bug (shown in
1741        pcretest format) are:
1743          /(?-x: )/x
1744          /(?x)(?-x: \s*#\s*)/
1745          /((?i)[\x{c0}])/8
1746          /(?i:[\x{c0}])/8
1748        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1749        is now done differently.
1751     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1752        wrapper classes; (b) implement a new function in the C++ scanner that is
1753        more efficient than the old way of doing things because it avoids levels of
1754        recursion in the regex matching; (c) add a paragraph to the documentation
1755        for the FullMatch() function.
1757     6. The escape sequence \n was being treated as whatever was defined as
1758        "newline". Not only was this contrary to the documentation, which states
1759        that \n is character 10 (hex 0A), but it also went horribly wrong when
1760        "newline" was defined as CRLF. This has been fixed.
1762     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1763        was being set to -1 for the "end of line" case (supposedly a value that no
1764        character can have). Though this value is never used (the check for end of
1765        line is "zero bytes in current character"), it caused compiler complaints.
1766        I've changed it to 0xffffffff.
1768     8. In pcre_version.c, the version string was being built by a sequence of
1769        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1770        string (as it is for production releases) called a macro with an empty
1771        argument. The C standard says the result of this is undefined. The gcc
1772        compiler treats it as an empty string (which was what was wanted) but it is
1773        reported that Visual C gives an error. The source has been hacked around to
1774        avoid this problem.
1776     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1777        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1778        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1779        of them did).
1781    10. Originally, pcretest opened its input and output without "b"; then I was
1782        told that "b" was needed in some environments, so it was added for release
1783        5.0 to both the input and output. (It makes no difference on Unix-like
1784        systems.) Later I was told that it is wrong for the input on Windows. I've
1785        now abstracted the modes into two macros, to make it easier to fiddle with
1786        them, and removed "b" from the input mode under Windows.
1788    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1790    12. Added -help and --help to pcretest as an official way of being reminded
1791        of the options.
1793    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1794        and pcrecpp.cc because they annoy compilers at high warning levels.
1796    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1798    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1799        scripts are not C programs :-) and which was not noticed because it works
1800        on Linux.
1802    16. pcretest is supposed to handle any length of pattern and data line (as one
1803        line or as a continued sequence of lines) by extending its input buffer if
1804        necessary. This feature was broken for very long pattern lines, leading to
1805        a string of junk being passed to pcre_compile() if the pattern was longer
1806        than about 50K.
1808    17. I have done a major re-factoring of the way pcre_compile() computes the
1809        amount of memory needed for a compiled pattern. Previously, there was code
1810        that made a preliminary scan of the pattern in order to do this. That was
1811        OK when PCRE was new, but as the facilities have expanded, it has become
1812        harder and harder to keep it in step with the real compile phase, and there
1813        have been a number of bugs (see for example, 4 above). I have now found a
1814        cunning way of running the real compile function in a "fake" mode that
1815        enables it to compute how much memory it would need, while actually only
1816        ever using a few hundred bytes of working memory and without too many
1817        tests of the mode. This should make future maintenance and development
1818        easier. A side effect of this work is that the limit of 200 on the nesting
1819        depth of parentheses has been removed (though this was never a serious
1820        limitation, I suspect). However, there is a downside: pcre_compile() now
1821        runs more slowly than before (30% or more, depending on the pattern). I
1822        hope this isn't a big issue. There is no effect on runtime performance.
1824    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1825        newline (only possible for the last line of a file) and it was a
1826        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1828    19. Added additional timing features to pcretest. (1) The -tm option now times
1829        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1830        separate command line item, by a number that specifies the number of
1831        repeats to use when timing. The default is 50000; this gives better
1832        precision, but takes uncomfortably long for very large patterns.
1834    20. Extended pcre_study() to be more clever in cases where a branch of a
1835        subpattern has no definite first character. For example, (a*|b*)[cd] would
1836        previously give no result from pcre_study(). Now it recognizes that the
1837        first character must be a, b, c, or d.
1839    21. There was an incorrect error "recursive call could loop indefinitely" if
1840        a subpattern (or the entire pattern) that was being tested for matching an
1841        empty string contained only one non-empty item after a nested subpattern.
1842        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1843        incorrectly, because the \d was being skipped in the check.
1845    22. The pcretest program now has a new pattern option /B and a command line
1846        option -b, which is equivalent to adding /B to every pattern. This causes
1847        it to show the compiled bytecode, without the additional information that
1848        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1849        is the same as /B/I).
1851    23. A new optimization is now able automatically to treat some sequences such
1852        as a*b as a*+b. More specifically, if something simple (such as a character
1853        or a simple class like \d) has an unlimited quantifier, and is followed by
1854        something that cannot possibly match the quantified thing, the quantifier
1855        is automatically "possessified".
1857    24. A recursive reference to a subpattern whose number was greater than 39
1858        went wrong under certain circumstances in UTF-8 mode. This bug could also
1859        have affected the operation of pcre_study().
1861    25. Realized that a little bit of performance could be had by replacing
1862        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1864    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1866    27. Possessive quantifiers such as a++ were previously implemented by turning
1867        them into atomic groups such as ($>a+). Now they have their own opcodes,
1868        which improves performance. This includes the automatically created ones
1869        from 23 above.
1871    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1872        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1873        the first matched character to be a colon. This applied both to named and
1874        numbered groups.
1876    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1878    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1879        building PCRE on Windows easier, so I have included it in the distribution.
1881    31. There is now a check in pcretest against a ridiculously large number being
1882        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1883        loop, the loop is abandoned.
1885    32. Forward references to subpatterns in conditions such as (?(2)...) where
1886        subpattern 2 is defined later cause pcre_compile() to search forwards in
1887        the pattern for the relevant set of parentheses. This search went wrong
1888        when there were unescaped parentheses in a character class, parentheses
1889        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1891    33. "Subroutine" calls and backreferences were previously restricted to
1892        referencing subpatterns earlier in the regex. This restriction has now
1893        been removed.
1895    34. Added a number of extra features that are going to be in Perl 5.10. On the
1896        whole, these are just syntactic alternatives for features that PCRE had
1897        previously implemented using the Python syntax or my own invention. The
1898        other formats are all retained for compatibility.
1900        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1901            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1902            also .NET compatible.
1904        (b) A recursion or subroutine call to a named group can now be defined as
1905            (?&name) as well as (?P>name).
1907        (c) A backreference to a named group can now be defined as \k<name> or
1908            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1909            5.10, are also .NET compatible.
1911        (d) A conditional reference to a named group can now use the syntax
1912            (?(<name>) or (?('name') as well as (?(name).
1914        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1915            groups (named and numbered) that are never evaluated inline, but can be
1916            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1917            is always false. There may be only one alternative in such a group.
1919        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1920            as the simple (?(R). The condition is true only if the most recent
1921            recursion is that of the given number or name. It does not search out
1922            through the entire recursion stack.
1924        (g) The escape \gN or \g{N} has been added, where N is a positive or
1925            negative number, specifying an absolute or relative reference.
1927    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1928        some "unreachable code" warnings.
1930    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1931        things, this adds five new scripts.
1933    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1934        There were also incompatibilities regarding the handling of \Q..\E inside
1935        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1936        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1938    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1939        matches an empty string, and forcibly breaks the loop. There were bugs in
1940        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1941        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1942        separate and independent bugs (that affected different cases) have been
1943        fixed.
1945    39. Refactored the code to abolish the use of different opcodes for small
1946        capturing bracket numbers. This is a tidy that I avoided doing when I
1947        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1948        The new approach is not only tidier, it makes it possible to reduce the
1949        memory needed to fix the previous bug (38).
1951    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1952        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1953        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1954        mode.
1956    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1957        report.
1959    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1960        copy construction and assignment in the C++ wrapper.
1962    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1963        couple of bugs that could have given wrong results in the "--newline=crlf"
1964        case.
1966    44. Added a number of casts and did some reorganization of signed/unsigned int
1967        variables following suggestions from Dair Grant. Also renamed the variable
1968        "this" as "item" because it is a C++ keyword.
1970    45. Arranged for dftables to add
1972          #include "pcre_internal.h"
1974        to pcre_chartables.c because without it, gcc 4.x may remove the array
1975        definition from the final binary if PCRE is built into a static library and
1976        dead code stripping is activated.
1978    46. For an unanchored pattern, if a match attempt fails at the start of a
1979        newline sequence, and the newline setting is CRLF or ANY, and the next two
1980        characters are CRLF, advance by two characters instead of one.
1983    Version 6.7 04-Jul-06
1984    ---------------------
1986     1. In order to handle tests when input lines are enormously long, pcretest has
1987        been re-factored so that it automatically extends its buffers when
1988        necessary. The code is crude, but this _is_ just a test program. The
1989        default size has been increased from 32K to 50K.
1991     2. The code in pcre_study() was using the value of the re argument before
1992        testing it for NULL. (Of course, in any sensible call of the function, it
1993        won't be NULL.)
1995     3. The memmove() emulation function in pcre_internal.h, which is used on
1996        systems that lack both memmove() and bcopy() - that is, hardly ever -
1997        was missing a "static" storage class specifier.
1999     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2000        containing an extended class (one that cannot be represented by a bitmap
2001        because it contains high-valued characters or Unicode property items, e.g.
2002        [\pZ]). Almost always one would set UTF-8 mode when processing such a
2003        pattern, but PCRE should not loop if you do not (it no longer does).
2004        [Detail: two cases were found: (a) a repeated subpattern containing an
2005        extended class; (b) a recursive reference to a subpattern that followed a
2006        previous extended class. It wasn't skipping over the extended class
2007        correctly when UTF-8 mode was not set.]
2009     5. A negated single-character class was not being recognized as fixed-length
2010        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2011        compile error "lookbehind assertion is not fixed length".
2013     6. The RunPerlTest auxiliary script was showing an unexpected difference
2014        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2015        write a Perl script that can interpret lines of an input file either as
2016        byte characters or as UTF-8, which is what "perltest" was being required to
2017        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2018        can't do is switch easily at run time between having the "use utf8;" pragma
2019        or not. In the end, I fudged it by using the RunPerlTest script to insert
2020        "use utf8;" explicitly for the UTF-8 tests.
2022     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2023        the end of the subject string, contrary to the documentation and to what
2024        Perl does. This was true of both matching functions. Now it matches only at
2025        the start of the subject and immediately after *internal* newlines.
2027     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2028        a pointer to an int instead of a pointer to an unsigned long int. This
2029        caused problems on 64-bit systems.
2031     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2032        instance of the 'standard' template library not being so standard".
2034    10. There was no check on the number of named subpatterns nor the maximum
2035        length of a subpattern name. The product of these values is used to compute
2036        the size of the memory block for a compiled pattern. By supplying a very
2037        long subpattern name and a large number of named subpatterns, the size
2038        computation could be caused to overflow. This is now prevented by limiting
2039        the length of names to 32 characters, and the number of named subpatterns
2040        to 10,000.
2042    11. Subpatterns that are repeated with specific counts have to be replicated in
2043        the compiled pattern. The size of memory for this was computed from the
2044        length of the subpattern and the repeat count. The latter is limited to
2045        65535, but there was no limit on the former, meaning that integer overflow
2046        could in principle occur. The compiled length of a repeated subpattern is
2047        now limited to 30,000 bytes in order to prevent this.
2049    12. Added the optional facility to have named substrings with the same name.
2051    13. Added the ability to use a named substring as a condition, using the
2052        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2053        are numbers (not recommended). Forward references are permitted.
2055    14. Added forward references in named backreferences (if you see what I mean).
2057    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2058        pattern could run off the end of the subject. For example, the pattern
2059        "(?s)(.{1,5})"8 did this with the subject "ab".
2061    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2062        PCRE_CASELESS was set when matching characters that were quantified with ?
2063        or *.
2065    17. A character class other than a single negated character that had a minimum
2066        but no maximum quantifier - for example [ab]{6,} - was not handled
2067        correctly by pce_dfa_exec(). It would match only one character.
2069    18. A valid (though odd) pattern that looked like a POSIX character
2070        class but used an invalid character after [ (for example [[,abc,]]) caused
2071        pcre_compile() to give the error "Failed: internal error: code overflow" or
2072        in some cases to crash with a glibc free() error. This could even happen if
2073        the pattern terminated after [[ but there just happened to be a sequence of
2074        letters, a binary zero, and a closing ] in the memory that followed.
2076    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2077        over the years. Originally (before any Unicode support), just the bottom 8
2078        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2079        output from "man perlunicode" includes this:
2081          The regular expression compiler produces polymorphic opcodes.  That
2082          is, the pattern adapts to the data and automatically switches to
2083          the Unicode character scheme when presented with Unicode data--or
2084          instead uses a traditional byte scheme when presented with byte
2085          data.
2087        Sadly, a wide octal escape does not cause a switch, and in a string with
2088        no other multibyte characters, these octal escapes are treated as before.
2089        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2090        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2091        Unicode string.
2093        I have not perpetrated such confusion in PCRE. Up till now, it took just
2094        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2095        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2096        translate to the appropriate multibyte character.
2098    29. Applied some refactoring to reduce the number of warnings from Microsoft
2099        and Borland compilers. This has included removing the fudge introduced
2100        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2101        a warning about an unused variable.
2103    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2104        characters since release 4.0, because Perl (from release 5.004) does not.
2105        [Or at least, is documented not to: some releases seem to be in conflict
2106        with the documentation.] However, when a pattern was studied with
2107        pcre_study() and all its branches started with \s, PCRE still included VT
2108        as a possible starting character. Of course, this did no harm; it just
2109        caused an unnecessary match attempt.
2111    22. Removed a now-redundant internal flag bit that recorded the fact that case
2112        dependency changed within the pattern. This was once needed for "required
2113        byte" processing, but is no longer used. This recovers a now-scarce options
2114        bit. Also moved the least significant internal flag bit to the most-
2115        significant bit of the word, which was not previously used (hangover from
2116        the days when it was an int rather than a uint) to free up another bit for
2117        the future.
2119    23. Added support for CRLF line endings as well as CR and LF. As well as the
2120        default being selectable at build time, it can now be changed at runtime
2121        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2122        specify that it is scanning data with non-default line endings.
2124    24. Changed the definition of CXXLINK to make it agree with the definition of
2125        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2127    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2128        recursions. This makes a big different to stack usage for some patterns.
2130    26. If a subpattern containing a named recursion or subroutine reference such
2131        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2132        the space required for the compiled pattern went wrong and gave too small a
2133        value. Depending on the environment, this could lead to "Failed: internal
2134        error: code overflow at offset 49" or "glibc detected double free or
2135        corruption" errors.
2137    27. Applied patches from Google (a) to support the new newline modes and (b) to
2138        advance over multibyte UTF-8 characters in GlobalReplace.
2140    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2141        difference for some implementation of PCRE in some Windows version.
2143    29. Added some extra testing facilities to pcretest:
2145        \q<number>   in a data line sets the "match limit" value
2146        \Q<number>   in a data line sets the "match recursion limt" value
2147        -S <number>  sets the stack size, where <number> is in megabytes
2149        The -S option isn't available for Windows.
2152    Version 6.6 06-Feb-06
2153    ---------------------
2155     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2156        in pcreposix.h. I have copied the definition from pcre.h.
2158     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2159        because pcre.h is no longer a built file.
2161     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2162        not normally included in the compiled code.
2165    Version 6.5 01-Feb-06
2166    ---------------------
2168     1. When using the partial match feature with pcre_dfa_exec(), it was not
2169        anchoring the second and subsequent partial matches at the new starting
2170        point. This could lead to incorrect results. For example, with the pattern
2171        /1234/, partially matching against "123" and then "a4" gave a match.
2173     2. Changes to pcregrep:
2175        (a) All non-match returns from pcre_exec() were being treated as failures
2176            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2177            error message is output. Some extra information is given for the
2178            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2179            probably the only errors that are likely to be caused by users (by
2180            specifying a regex that has nested indefinite repeats, for instance).
2181            If there are more than 20 of these errors, pcregrep is abandoned.
2183        (b) A binary zero was treated as data while matching, but terminated the
2184            output line if it was written out. This has been fixed: binary zeroes
2185            are now no different to any other data bytes.
2187        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2188            used to set a locale for matching. The --locale=xxxx long option has
2189            been added (no short equivalent) to specify a locale explicitly on the
2190            pcregrep command, overriding the environment variables.
2192        (d) When -B was used with -n, some line numbers in the output were one less
2193            than they should have been.
2195        (e) Added the -o (--only-matching) option.
2197        (f) If -A or -C was used with -c (count only), some lines of context were
2198            accidentally printed for the final match.
2200        (g) Added the -H (--with-filename) option.
2202        (h) The combination of options -rh failed to suppress file names for files
2203            that were found from directory arguments.
2205        (i) Added the -D (--devices) and -d (--directories) options.
2207        (j) Added the -F (--fixed-strings) option.
2209        (k) Allow "-" to be used as a file name for -f as well as for a data file.
2211        (l) Added the --colo(u)r option.
2213        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2214            is not present by default.
2216     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2217        items such as (?R) or (?1), when the recursion could match a number of
2218        alternatives. If it matched one of the alternatives, but subsequently,
2219        outside the recursion, there was a failure, the code tried to back up into
2220        the recursion. However, because of the way PCRE is implemented, this is not
2221        possible, and the result was an incorrect result from the match.
2223        In order to prevent this happening, the specification of recursion has
2224        been changed so that all such subpatterns are automatically treated as
2225        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2227     4. I had overlooked the fact that, in some locales, there are characters for
2228        which isalpha() is true but neither isupper() nor islower() are true. In
2229        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2230        and ordfeminine) are like this. This affected the treatment of \w and \W
2231        when they appeared in character classes, but not when they appeared outside
2232        a character class. The bit map for "word" characters is now created
2233        separately from the results of isalnum() instead of just taking it from the
2234        upper, lower, and digit maps. (Plus the underscore character, of course.)
2236     5. The above bug also affected the handling of POSIX character classes such as
2237        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2238        permanent tables. Instead, the bit maps for such a class were previously
2239        created as the appropriate unions of the upper, lower, and digit bitmaps.
2240        Now they are created by subtraction from the [[:word:]] class, which has
2241        its own bitmap.
2243     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2244        It is created by subtracting the vertical space characters (\x09, \x0a,
2245        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2246        subtraction was done in the overall bitmap for a character class, meaning
2247        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2248        be recognized. This bug has been fixed.
2250     7. Patches from the folks at Google:
2252          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2253          real life, but is still worth protecting against".
2255          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2256          regular expressions".
2258          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2259          have it.
2261          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2262          "configure" and the latter not, in order to fix a problem somebody had
2263          with compiling the Arg class on HP-UX.
2265          (e) Improve the error-handling of the C++ wrapper a little bit.
2267          (f) New tests for checking recursion limiting.
2269     8. The pcre_memmove() function, which is used only if the environment does not
2270        have a standard memmove() function (and is therefore rarely compiled),
2271        contained two bugs: (a) use of int instead of size_t, and (b) it was not
2272        returning a result (though PCRE never actually uses the result).
2274     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2275        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2276        returned instead of calling malloc() with an overflowing number that would
2277        most likely cause subsequent chaos.
2279    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2281    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2282        with this option is matched, the nmatch and pmatch options of regexec() are
2283        ignored.
2285    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2286        provided in case anyone wants to the the POSIX interface with UTF-8
2287        strings.
2289    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2290        C++ linking (needed for some HP-UX environments).
2292    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2293        (unused parameter) and in the pcre_printint() function (omitted "default"
2294        switch label when the default is to do nothing).
2296    15. Added some code to make it possible, when PCRE is compiled as a C++
2297        library, to replace subject pointers for pcre_exec() with a smart pointer
2298        class, thus making it possible to process discontinuous strings.
2300    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2301        much the same function. They were added by different people who were trying
2302        to make PCRE easy to compile on non-Unix systems. It has been suggested
2303        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2304        for compiling on Windows systems. I have therefore replaced it with
2305        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2306        defaults to "extern" for C or "extern C" for C++, which works fine on
2307        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2308        SCOPE with something explicit in config.h. In addition:
2310        (a) pcreposix.h still had just "extern" instead of either of these macros;
2311            I have replaced it with PCRE_DATA_SCOPE.
2313        (b) Functions such as _pcre_xclass(), which are internal to the library,
2314            but external in the C sense, all had PCRE_EXPORT in their definitions.
2315            This is apparently wrong for the Windows case, so I have removed it.
2316            (It makes no difference on Unix-like systems.)
2318    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2319        of recursive calls to match(). This is different to MATCH_LIMIT because
2320        that limits the total number of calls to match(), not all of which increase
2321        the depth of recursion. Limiting the recursion depth limits the amount of
2322        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2323        when PCRE is compiled, and changed at run time. A patch from Google adds
2324        this functionality to the C++ interface.
2326    18. Changes to the handling of Unicode character properties:
2328        (a) Updated the table to Unicode 4.1.0.
2330        (b) Recognize characters that are not in the table as "Cn" (undefined).
2332        (c) I revised the way the table is implemented to a much improved format
2333            which includes recognition of ranges. It now supports the ranges that
2334            are defined in UnicodeData.txt, and it also amalgamates other
2335            characters into ranges. This has reduced the number of entries in the
2336            table from around 16,000 to around 3,000, thus reducing its size
2337            considerably. I realized I did not need to use a tree structure after
2338            all - a binary chop search is just as efficient. Having reduced the
2339            number of entries, I extended their size from 6 bytes to 8 bytes to
2340            allow for more data.
2342        (d) Added support for Unicode script names via properties such as \p{Han}.
2344    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2345        matching that character.
2347    20. When matching a repeated Unicode property with a minimum greater than zero,
2348        (for example \pL{2,}), PCRE could look past the end of the subject if it
2349        reached it while seeking the minimum number of characters. This could
2350        happen only if some of the characters were more than one byte long, because
2351        there is a check for at least the minimum number of bytes.
2353    21. Refactored the implementation of \p and \P so as to be more general, to
2354        allow for more different types of property in future. This has changed the
2355        compiled form incompatibly. Anybody with saved compiled patterns that use
2356        \p or \P will have to recompile them.
2358    22. Added "Any" and "L&" to the supported property types.
2360    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2361        but give a compile time error if the value is greater than 0xff.
2363    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2364        accidentally not being installed or uninstalled.
2366    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2367        made were to insert the current release number. This seemed silly, because
2368        it made things harder for people building PCRE on systems that don't run
2369        "configure". I have turned pcre.h into a distributed file, no longer built
2370        by "configure", with the version identification directly included. There is
2371        no longer a pcre.h.in file.
2373        However, this change necessitated a change to the pcre-config script as
2374        well. It is built from pcre-config.in, and one of the substitutions was the
2375        release number. I have updated configure.ac so that ./configure now finds
2376        the release number by grepping pcre.h.
2378    26. Added the ability to run the tests under valgrind.
2381    Version 6.4 05-Sep-05
2382    ---------------------
2384     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2385        "--" to be printed when multiple files were scanned, even when none of the
2386        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2387        consider it to be a bug, and have restored the previous behaviour.
2389     2. A couple of code tidies to get rid of compiler warnings.
2391     3. The pcretest program used to cheat by referring to symbols in the library
2392        whose names begin with _pcre_. These are internal symbols that are not
2393        really supposed to be visible externally, and in some environments it is
2394        possible to suppress them. The cheating is now confined to including
2395        certain files from the library's source, which is a bit cleaner.
2397     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2398        file's purpose clearer.
2400     5. Reorganized pcre_ucp_findchar().
2403    Version 6.3 15-Aug-05
2404    ---------------------
2406     1. The file libpcre.pc.in did not have general read permission in the tarball.
2408     2. There were some problems when building without C++ support:
2410        (a) If C++ support was not built, "make install" and "make test" still
2411            tried to test it.
2413        (b) There were problems when the value of CXX was explicitly set. Some
2414            changes have been made to try to fix these, and ...
2416        (c) --disable-cpp can now be used to explicitly disable C++ support.
2418        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2419            backslash in a target when C++ was disabled. This confuses some
2420            versions of "make", apparently. Using an intermediate variable solves
2421            this. (Same for CPP_LOBJ.)
2423     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2424        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2425        necessary on certain architectures.
2427     4. Added a setting of -export-symbols-regex to the link command to remove
2428        those symbols that are exported in the C sense, but actually are local
2429        within the library, and not documented. Their names all begin with
2430        "_pcre_". This is not a perfect job, because (a) we have to except some
2431        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2432        available (and never for static libraries). I have made a note to try to
2433        find a way round (a) in the future.
2436    Version 6.2 01-Aug-05
2437    ---------------------
2439     1. There was no test for integer overflow of quantifier values. A construction
2440        such as {1111111111111111} would give undefined results. What is worse, if
2441        a minimum quantifier for a parenthesized subpattern overflowed and became
2442        negative, the calculation of the memory size went wrong. This could have
2443        led to memory overwriting.
2445     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2447     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2448        operating environments where this matters.
2450     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2451        PCRE options from within the C++ wrapper.
2453     5. Named capturing subpatterns were not being correctly counted when a pattern
2454        was compiled. This caused two problems: (a) If there were more than 100
2455        such subpatterns, the calculation of the memory needed for the whole
2456        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2457        back references of the form \12, where the number was greater than 9, were
2458        not recognized as back references, even though there were sufficient
2459        previous subpatterns.
2461     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2462        versions of gcc, e.g. 2.95.4.
2465    Version 6.1 21-Jun-05
2466    ---------------------
2468     1. There was one reference to the variable "posix" in pcretest.c that was not
2469        surrounded by "#if !defined NOPOSIX".
2471     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2472        the cross-check on the old pcre_info() function, for the benefit of the
2473        cut-down version of PCRE that is currently imported into Exim.
2475     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2476        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2477        patterns that start (?i) but I don't think that matters. The use of (?i) is
2478        just an example; this all applies to the other options as well.
2480     4. Since libtool seems to echo the compile commands it is issuing, the output
2481        from "make" can be reduced a bit by putting "@" in front of each libtool
2482        compile command.
2484     5. Patch from the folks at Google for configure.in to be a bit more thorough
2485        in checking for a suitable C++ installation before trying to compile the
2486        C++ stuff. This should fix a reported problem when a compiler was present,
2487        but no suitable headers.
2489     6. The man pages all had just "PCRE" as their title. I have changed them to
2490        be the relevant file name. I have also arranged that these names are
2491        retained in the file doc/pcre.txt, which is a concatenation in text format
2492        of all the man pages except the little individual ones for each function.
2494     7. The NON-UNIX-USE file had not been updated for the different set of source
2495        files that come with release 6. I also added a few comments about the C++
2496        wrapper.
2499    Version 6.0 07-Jun-05
2500    ---------------------
2502     1. Some minor internal re-organization to help with my DFA experiments.
2504     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2505        didn't matter for the library itself when fully configured, but did matter
2506        when compiling without UCP support, or within Exim, where the ucp files are
2507        not imported.
2509     3. Refactoring of the library code to split up the various functions into
2510        different source modules. The addition of the new DFA matching code (see
2511        below) to a single monolithic source would have made it really too
2512        unwieldy, quite apart from causing all the code to be include in a
2513        statically linked application, when only some functions are used. This is
2514        relevant even without the DFA addition now that patterns can be compiled in
2515        one application and matched in another.
2517        The downside of splitting up is that there have to be some external
2518        functions and data tables that are used internally in different modules of
2519        the library but which are not part of the API. These have all had their
2520        names changed to start with "_pcre_" so that they are unlikely to clash
2521        with other external names.
2523     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2524        a different (DFA) algorithm. Although it is slower than the original
2525        function, it does have some advantages for certain types of matching
2526        problem.
2528     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2529        including restarting after a partial match.
2531     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2532        defined when compiling for Windows was sent to me. I have put it into the
2533        code, though I have no means of testing or verifying it.
2535     7. Added the pcre_refcount() auxiliary function.
2537     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2538        match before or at the first newline in the subject string. In pcretest,
2539        the /f option on a pattern can be used to set this.
2541     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2542        would behave wrongly. This has been present in PCRE since release 4.0.
2544    10. A number of changes to the pcregrep command:
2546        (a) Refactored how -x works; insert ^(...)$ instead of setting
2547            PCRE_ANCHORED and checking the length, in preparation for adding
2548            something similar for -w.
2550        (b) Added the -w (match as a word) option.
2552        (c) Refactored the way lines are read and buffered so as to have more
2553            than one at a time available.
2555        (d) Implemented a pcregrep test script.
2557        (e) Added the -M (multiline match) option. This allows patterns to match
2558            over several lines of the subject. The buffering ensures that at least
2559            8K, or the rest of the document (whichever is the shorter) is available
2560            for matching (and similarly the previous 8K for lookbehind assertions).
2562        (f) Changed the --help output so that it now says
2564              -w, --word-regex(p)
2566            instead of two lines, one with "regex" and the other with "regexp"
2567            because that confused at least one person since the short forms are the
2568            same. (This required a bit of code, as the output is generated
2569            automatically from a table. It wasn't just a text change.)
2571        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2572            option but starts with a hyphen. Could be a pattern or a path name
2573            starting with a hyphen, for instance.
2575        (h) "-" can be given as a file name to represent stdin.
2577        (i) When file names are being printed, "(standard input)" is used for
2578            the standard input, for compatibility with GNU grep. Previously
2579            "<stdin>" was used.
2581        (j) The option --label=xxx can be used to supply a name to be used for
2582            stdin when file names are being printed. There is no short form.
2584        (k) Re-factored the options decoding logic because we are going to add
2585            two more options that take data. Such options can now be given in four
2586            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2588        (l) Added the -A, -B, and -C options for requesting that lines of context
2589            around matches be printed.
2591        (m) Added the -L option to print the names of files that do not contain
2592            any matching lines, that is, the complement of -l.
2594        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2595            continue to scan other files.
2597        (o) The -s option was incorrectly implemented. For compatibility with other
2598            greps, it now suppresses the error message for a non-existent or non-
2599            accessible file (but not the return code). There is a new option called
2600            -q that suppresses the output of matching lines, which was what -s was
2601            previously doing.
2603        (p) Added --include and --exclude options to specify files for inclusion
2604            and exclusion when recursing.
2606    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2607        Hopefully, it now does.
2609    12. Missing cast in pcre_study().
2611    13. Added an "uninstall" target to the makefile.
2613    14. Replaced "extern" in the function prototypes in Makefile.in with
2614        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2615        world, but is set differently for Windows.
2617    15. Added a second compiling function called pcre_compile2(). The only
2618        difference is that it has an extra argument, which is a pointer to an
2619        integer error code. When there is a compile-time failure, this is set
2620        non-zero, in addition to the error test pointer being set to point to an
2621        error message. The new argument may be NULL if no error number is required
2622        (but then you may as well call pcre_compile(), which is now just a
2623        wrapper). This facility is provided because some applications need a
2624        numeric error indication, but it has also enabled me to tidy up the way
2625        compile-time errors are handled in the POSIX wrapper.
2627    16. Added VPATH=.libs to the makefile; this should help when building with one
2628        prefix path and installing with another. (Or so I'm told by someone who
2629        knows more about this stuff than I do.)
2631    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2632        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2633        match everything, including newlines. This is not POSIX-compatible, but
2634        somebody wanted the feature. From pcretest it can be activated by using
2635        both the P and the s flags.
2637    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2639    19. libpcre.pc was being incorrectly installed as executable.
2641    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2642        it now also looks for '\r' so that it will work unmodified on Windows.
2644    21. Added Google's contributed C++ wrapper to the distribution.
2646    22. Added some untidy missing memory free() calls in pcretest, to keep
2647        Electric Fence happy when testing.
2651    Version 5.0 13-Sep-04
2652    ---------------------
2654     1. Internal change: literal characters are no longer packed up into items
2655        containing multiple characters in a single byte-string. Each character
2656        is now matched using a separate opcode. However, there may be more than one
2657        byte in the character in UTF-8 mode.
2659     2. The pcre_callout_block structure has two new fields: pattern_position and
2660        next_item_length. These contain the offset in the pattern to the next match
2661        item, and its length, respectively.
2663     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2664        insertion of callouts before each pattern item. Added the /C option to
2665        pcretest to make use of this.
2667     4. On the advice of a Windows user, the lines
2669          #if defined(_WIN32) || defined(WIN32)
2670          _setmode( _fileno( stdout ), 0x8000 );
2671          #endif  /* defined(_WIN32) || defined(WIN32) */
2673        have been added to the source of pcretest. This apparently does useful
2674        magic in relation to line terminators.
2676     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2677        for the benefit of those environments where the "b" makes a difference.
2679     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2680        to know about it. I have put a hack into configure.in that adds in code
2681        to set GCC=yes if CC=icc. This seems to end up at a point in the
2682        generated configure script that is early enough to affect the setting of
2683        compiler options, which is what is needed, but I have no means of testing
2684        whether it really works. (The user who reported this had patched the
2685        generated configure script, which of course I cannot do.)
2687        LATER: After change 22 below (new libtool files), the configure script
2688        seems to know about icc (and also ecc). Therefore, I have commented out
2689        this hack in configure.in.
2691     7. Added support for pkg-config (2 patches were sent in).
2693     8. Negated POSIX character classes that used a combination of internal tables
2694        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2695        [[:^ascii]]. Typically, they would match almost any characters. The other
2696        POSIX classes were not broken in this way.
2698     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2699        to find the match, as PCRE was deluded into thinking that the match had to
2700        start at the start point or following a newline. The same bug applied to
2701        patterns with negative forward assertions or any backward assertions
2702        preceding ".*" at the start, unless the pattern required a fixed first
2703        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2705    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2706        starting at the last subject character, bytes beyond the end of the subject
2707        string were read.
2709    11. Renamed the variable "class" as "classbits" to make life easier for C++
2710        users. (Previously there was a macro definition, but it apparently wasn't
2711        enough.)
2713    12. Added the new field "tables" to the extra data so that tables can be passed
2714        in at exec time, or the internal tables can be re-selected. This allows
2715        a compiled regex to be saved and re-used at a later time by a different
2716        program that might have everything at different addresses.
2718    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2719        -R library as well as a -L library.
2721    14. The debugging options of pcretest (-d on the command line or D on a
2722        pattern) showed incorrect output for anything following an extended class
2723        that contained multibyte characters and which was followed by a quantifier.
2725    15. Added optional support for general category Unicode character properties
2726        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2727        support. It adds about 90K to the size of the library. The meanings of the
2728        inbuilt class escapes such as \d and \s have NOT been changed.
2730    16. Updated pcredemo.c to include calls to free() to release the memory for the
2731        compiled pattern.
2733    17. The generated file chartables.c was being created in the source directory
2734        instead of in the building directory. This caused the build to fail if the
2735        source directory was different from the building directory, and was
2736        read-only.
2738    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2739        file. No doubt somebody will tell me if they don't make sense... Also added
2740        Dan Mooney's comments about building on OpenVMS.
2742    19. Added support for partial matching via the PCRE_PARTIAL option for
2743        pcre_exec() and the \P data escape in pcretest.
2745    20. Extended pcretest with 3 new pattern features:
2747        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2748              write the compiled pattern to the file whose name is "rest-of-line".
2749              This is a straight binary dump of the data, with the saved pointer to
2750              the character tables forced to be NULL. The study data, if any, is
2751              written too. After writing, pcretest reads a new pattern.
2753        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2754              compiled pattern from the given file. There must not be any
2755              occurrences of "<" in the file name (pretty unlikely); if there are,
2756              pcretest will instead treat the initial "<" as a pattern delimiter.
2757              After reading in the pattern, pcretest goes on to read data lines as
2758              usual.
2760        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2761              and 16-bit fields in a compiled pattern, to simulate a pattern that
2762              was compiled on a host of opposite endianness.
2764    21. The pcre-exec() function can now cope with patterns that were compiled on
2765        hosts of opposite endianness, with this restriction:
2767          As for any compiled expression that is saved and used later, the tables
2768          pointer field cannot be preserved; the extra_data field in the arguments
2769          to pcre_exec() should be used to pass in a tables address if a value
2770          other than the default internal tables were used at compile time.
2772    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2773        now diagnosed as an error. Previously, most of the time, a negative number
2774        would have been treated as zero, but if in addition "ovector" was passed as
2775        NULL, a crash could occur.
2777    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2778        new versions from the libtool 1.5 distribution (the last one is a copy of
2779        a file called libtool.m4). This seems to have fixed the need to patch
2780        "configure" to support Darwin 1.3 (which I used to do). However, I still
2781        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2782        workstation).
2784    24. Changed the PCRE licence to be the more standard "BSD" licence.
2787    Version 4.5 01-Dec-03
2788    ---------------------
2790     1. There has been some re-arrangement of the code for the match() function so
2791        that it can be compiled in a version that does not call itself recursively.
2792        Instead, it keeps those local variables that need separate instances for
2793        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2794        needs to "recurse". Keeping track of where control must go is done by means
2795        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2796        hide most of the details from the main code, and operates only if
2797        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2798        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2799        operating.
2801        To make it easier for callers to provide specially tailored get/free
2802        functions for this usage, two new functions, pcre_stack_malloc, and
2803        pcre_stack_free, are used. They are always called in strict stacking order,
2804        and the size of block requested is always the same.
2806        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2807        PCRE has been compiled to use the stack or the heap for recursion. The
2808        -C option of pcretest uses this to show which version is compiled.
2810        A new data escape \S, is added to pcretest; it causes the amounts of store
2811        obtained and freed by both kinds of malloc/free at match time to be added
2812        to the output.
2814     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2815        what's available on my current Linux desktop machine.
2817     3. When matching a UTF-8 string, the test for a valid string at the start has
2818        been extended. If start_offset is not zero, PCRE now checks that it points
2819        to a byte that is the start of a UTF-8 character. If not, it returns
2820        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2821        this is necessary because there may be backward assertions in the pattern.
2822        When matching the same subject several times, it may save resources to use
2823        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2825     4. The code for checking the validity of UTF-8 strings has been tightened so
2826        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2827        containing "overlong sequences".
2829     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2830        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2831        should have been "&", but it just so happened that all the cases this let
2832        through by mistake were picked up later in the function.
2834     6. I had used a variable called "isblank" - this is a C99 function, causing
2835        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2837     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2838        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2839        so the version is shown; (c) stop "make test" echoing "./RunTest".
2841     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2843     9. The prototype for memmove() for systems that don't have it was using
2844        size_t, but the inclusion of the header that defines size_t was later. I've
2845        moved the #includes for the C headers earlier to avoid this.
2847    10. Added some adjustments to the code to make it easier to compiler on certain
2848        special systems:
2850          (a) Some "const" qualifiers were missing.
2851          (b) Added the macro EXPORT before all exported functions; by default this
2852              is defined to be empty.
2853          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2854              that it reads its output file name as an argument instead of writing
2855              to the standard output and assuming this can be redirected.
2857    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2858        class containing characters with values greater than 255, PCRE compilation
2859        went into a loop.
2861    12. A recursive reference to a subpattern that was within another subpattern
2862        that had a minimum quantifier of zero caused PCRE to crash. For example,
2863        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2864        recursion. If the recursively-called subpattern itself had a zero repeat,
2865        that was OK.
2867    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2868        buffer into which it was copied (for escape processing) was still set at
2869        1024, so long lines caused crashes.
2871    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2872        "internal error: code overflow...". This applied to any character class
2873        that was followed by a possessive quantifier.
2875    15. Modified the Makefile to add libpcre.la as a prerequisite for
2876        libpcreposix.la because I was told this is needed for a parallel build to
2877        work.
2879    16. If a pattern that contained .* following optional items at the start was
2880        studied, the wrong optimizing data was generated, leading to matching
2881        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2882        matching string must start with a or b or c. The correct conclusion for
2883        this pattern is that a match can start with any character.
2886    Version 4.4 13-Aug-03
2887    ---------------------
2889     1. In UTF-8 mode, a character class containing characters with values between
2890        127 and 255 was not handled correctly if the compiled pattern was studied.
2891        In fixing this, I have also improved the studying algorithm for such
2892        classes (slightly).
2894     2. Three internal functions had redundant arguments passed to them. Removal
2895        might give a very teeny performance improvement.
2897     3. Documentation bug: the value of the capture_top field in a callout is *one
2898        more than* the number of the hightest numbered captured substring.
2900     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2901        in incorrectly linking with a previously installed version. They now link
2902        explicitly with libpcre.la.
2904     5. configure.in no longer needs to recognize Cygwin specially.
2906     6. A problem in pcre.in for Windows platforms is fixed.
2908     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2909        pcretest, it used to include the size of the study block as part of its
2910        output. Unfortunately, the structure contains a field that has a different
2911        size on different hardware architectures. This meant that the tests that
2912        showed this size failed. As the block is currently always of a fixed size,
2913        this information isn't actually particularly useful in pcretest output, so
2914        I have just removed it.
2916     8. Three pre-processor statements accidentally did not start in column 1.
2917        Sadly, there are *still* compilers around that complain, even though
2918        standard C has not required this for well over a decade. Sigh.
2920     9. In pcretest, the code for checking callouts passed small integers in the
2921        callout_data field, which is a void * field. However, some picky compilers
2922        complained about the casts involved for this on 64-bit systems. Now
2923        pcretest passes the address of the small integer instead, which should get
2924        rid of the warnings.
2926    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2927        both compile and run time, and gives an error if an invalid UTF-8 sequence
2928        is found. There is a option for disabling this check in cases where the
2929        string is known to be correct and/or the maximum performance is wanted.
2931    11. In response to a bug report, I changed one line in Makefile.in from
2933            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2934        to
2935            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2937        to look similar to other lines, but I have no way of telling whether this
2938        is the right thing to do, as I do not use Windows. No doubt I'll get told
2939        if it's wrong...
2942    Version 4.3 21-May-03
2943    ---------------------
2945    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2946       Makefile.
2948    2. Some refactoring to improve the quality of the code:
2950       (i)   The utf8_table... variables are now declared "const".
2952       (ii)  The code for \cx, which used the "case flipping" table to upper case
2953             lower case letters, now just substracts 32. This is ASCII-specific,
2954             but the whole concept of \cx is ASCII-specific, so it seems
2955             reasonable.
2957       (iii) PCRE was using its character types table to recognize decimal and
2958             hexadecimal digits in the pattern. This is silly, because it handles
2959             only 0-9, a-f, and A-F, but the character types table is locale-
2960             specific, which means strange things might happen. A private
2961             table is now used for this - though it costs 256 bytes, a table is
2962             much faster than multiple explicit tests. Of course, the standard
2963             character types table is still used for matching digits in subject
2964             strings against \d.
2966       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2967             ending in _t are). So I've renamed it as ESC_tee.
2969    3. The first argument for regexec() in the POSIX wrapper should have been
2970       defined as "const".
2972    4. Changed pcretest to use malloc() for its buffers so that they can be
2973       Electric Fenced for debugging.
2975    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2976       to read one or more bytes before the start of the subject string. Often this
2977       had no effect on PCRE's behaviour, but in some circumstances it could
2978       provoke a segmentation fault.
2980    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2981       to try to read one or more bytes before the start of the subject string.
2983    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2984       UTF-8 support could misbehave in various ways if the subject string
2985       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2986       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2987       back over UTF-8 characters.)
2990    Version 4.2 14-Apr-03
2991    ---------------------
2993    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2995    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2996         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2997         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2998         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2999         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3000           and BUILD_EXEEXT
3001         Note: automatic setting of the BUILD variables is not yet working
3002         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3003           compile-time but not at link-time
3004         [LINK]: use for linking executables only
3005         make different versions for Windows and non-Windows
3006         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3007           libraries
3008         [LINK_FOR_BUILD]: new variable
3009         [OBJEXT]: use throughout
3010         [EXEEXT]: use throughout
3011         <winshared>: new target
3012         <wininstall>: new target
3013         <dftables.o>: use native compiler
3014         <dftables>: use native linker
3015         <install>: handle Windows platform correctly
3016         <clean>: ditto
3017         <check>: ditto
3018         copy DLL to top builddir before testing
3020       As part of these changes, -no-undefined was removed again. This was reported
3021       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3022       in any case.
3024    3. Some tidies to get rid of compiler warnings:
3026       . In the match_data structure, match_limit was an unsigned long int, whereas
3027         match_call_count was an int. I've made them both unsigned long ints.
3029       . In pcretest the fact that a const uschar * doesn't automatically cast to
3030         a void * provoked a warning.
3032       . Turning on some more compiler warnings threw up some "shadow" variables
3033         and a few more missing casts.
3035    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3036       option, a class that contained a single character with a value between 128
3037       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3039    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3040       option, a class that contained several characters, but with at least one
3041       whose value was between 128 and 255 caused PCRE to crash.
3044    Version 4.1 12-Mar-03
3045    ---------------------
3047    1. Compiling with gcc -pedantic found a couple of places where casts were
3048    needed, and a string in dftables.c that was longer than standard compilers are
3049    required to support.
3051    2. Compiling with Sun's compiler found a few more places where the code could
3052    be tidied up in order to avoid warnings.
3054    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3055    first of these names is deprecated in the latest Autoconf in favour of the name
3056    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3057    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3058    analogy I have changed it to CFLAGS_FOR_BUILD.
3060    4. Added -no-undefined to the linking command in the Makefile, because this is
3061    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3062    linking step for the pcreposix library.
3064    5. PCRE was failing to diagnose the case of two named groups with the same
3065    name.
3067    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3068    literal character that is needed in the subject for a match, and scans along to
3069    ensure that it is present before embarking on the full matching process. This
3070    saves time in cases of nested unlimited repeats that are never going to match.
3071    Problem: the scan can take a lot of time if the subject is very long (e.g.
3072    megabytes), thus penalizing straightforward matches. It is now done only if the
3073    amount of subject to be scanned is less than 1000 bytes.
3075    7. A lesser problem with the same optimization is that it was recording the
3076    first character of an anchored pattern as "needed", thus provoking a search
3077    right along the subject, even when the first match of the pattern was going to
3078    fail. The "needed" character is now not set for anchored patterns, unless it
3079    follows something in the pattern that is of non-fixed length. Thus, it still
3080    fulfils its original purpose of finding quick non-matches in cases of nested
3081    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3084    Version 4.0 17-Feb-03
3085    ---------------------
3087    1. If a comment in an extended regex that started immediately after a meta-item
3088    extended to the end of string, PCRE compiled incorrect data. This could lead to
3089    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3091    2. Moved to autoconf 2.53 and libtool 1.4.2.
3093    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3094    the special perltest8 script is no longer needed - all the tests can be run
3095    from a single perltest script.
3097    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3098    by \s. It has now been removed in PCRE. This means it isn't recognized as
3099    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3100    class [:space:] *does* include VT, thereby creating a mess.
3102    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3103    space and tab.
3105    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3106    its new features into the main test script, reducing the number of scripts.
3108    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3109    were backward compatible, and made the (?i) apply to the whole pattern, as if
3110    /i were given. Now it behaves more logically, and applies the option setting
3111    only to what follows. PCRE has been changed to follow suit. However, if it
3112    finds options settings right at the start of the pattern, it extracts them into
3113    the global options, as before. Thus, they show up in the info data.
3115    8. Added support for the \Q...\E escape sequence. Characters in between are
3116    treated as literals. This is slightly different from Perl in that $ and @ are
3117    also handled as literals inside the quotes. In Perl, they will cause variable
3118    interpolation. Note the following examples:
3120        Pattern            PCRE matches      Perl matches
3122        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
3123        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
3124        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
3126    For compatibility with Perl, \Q...\E sequences are recognized inside character
3127    classes as well as outside them.
3129    9. Re-organized 3 code statements in pcretest to avoid "overflow in
3130    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3131    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3132    signed/unsigned warnings.
3134    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3135    option for pcretest, so I've replaced it by a simple function that does just
3136    that job.
3138    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3139    "pcregrep -".
3141    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3142    Java package. This provides some syntactic sugar for simple cases of what my
3143    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3144    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3145    item, you can use this simplified notation. Note that only makes sense with
3146    greedy quantifiers. Consequently, the use of the possessive quantifier forces
3147    greediness, whatever the setting of the PCRE_UNGREEDY option.
3149    13. A change of greediness default within a pattern was not taking effect at
3150    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3151    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3152    was abstracted outside.
3154    14. PCRE now supports the \G assertion. It is true when the current matching
3155    position is at the start point of the match. This differs from \A when the
3156    starting offset is non-zero. Used with the /g option of pcretest (or similar
3157    code), it works in the same way as it does for Perl's /g option. If all
3158    alternatives of a regex begin with \G, the expression is anchored to the start
3159    match position, and the "anchored" flag is set in the compiled expression.
3161    15. Some bugs concerning the handling of certain option changes within patterns
3162    have been fixed. These applied to options other than (?ims). For example,
3163    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3164    been the other way round. Some of this was related to change 7 above.
3166    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3167    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3168    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3169    POSIX classes only within a class (e.g. /[[:alpha:]]/).
3171    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3172    mode. Unlike ".", it always matches newline, whatever the setting of
3173    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3174    assertions. Perl allows it, but it doesn't (in general) work because it can't
3175    calculate the length of the lookbehind. At least, that's the case for Perl
3176    5.8.0 - I've been told they are going to document that it doesn't work in
3177    future.
3179    18. Added an error diagnosis for escapes that PCRE does not support: these are
3180    \L, \l, \N, \P, \p, \U, \u, and \X.
3182    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3183    reading past the end of the pattern in cases such as /[abcd/.
3185    20. PCRE was getting more memory than necessary for patterns with classes that
3186    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3188    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3189    compiling PCRE for use with Virtual Pascal.
3191    22. Small fix to the Makefile to make it work properly if the build is done
3192    outside the source tree.
3194    23. Added a new extension: a condition to go with recursion. If a conditional
3195    subpattern starts with (?(R) the "true" branch is used if recursion has
3196    happened, whereas the "false" branch is used only at the top level.
3198    24. When there was a very long string of literal characters (over 255 bytes
3199    without UTF support, over 250 bytes with UTF support), the computation of how
3200    much memory was required could be incorrect, leading to segfaults or other
3201    strange effects.
3203    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3204    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3205    there was a subsequent back reference to those brackets. This meant that, for
3206    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3207    possible to check for precisely this case. All we can do is abandon the
3208    optimization if .* occurs inside capturing brackets when there are any back
3209    references whatsoever. (See below for a better fix that came later.)
3211    26. The handling of the optimization for finding the first character of a
3212    non-anchored pattern, and for finding a character that is required later in the
3213    match were failing in some cases. This didn't break the matching; it just
3214    failed to optimize when it could. The way this is done has been re-implemented.
3216    27. Fixed typo in error message for invalid (?R item (it said "(?p").
3218    28. Added a new feature that provides some of the functionality that Perl
3219    provides with (?{...}). The facility is termed a "callout". The way it is done
3220    in PCRE is for the caller to provide an optional function, by setting
3221    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3222    global variable. By default it is unset, which disables all calling out. To get
3223    the function called, the regex must include (?C) at appropriate points. This
3224    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3225    This provides a means of identifying different callout points. When PCRE
3226    reaches such a point in the regex, if pcre_callout has been set, the external
3227    function is called. It is provided with data in a structure called
3228    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3229    matching continues; if it returns a non-zero value, the match at the current
3230    point fails. However, backtracking will occur if possible. [This was changed
3231    later and other features added - see item 49 below.]
3233    29. pcretest is upgraded to test the callout functionality. It provides a
3234    callout function that displays information. By default, it shows the start of
3235    the match and the current position in the text. There are some new data escapes
3236    to vary what happens:
3238        \C+         in addition, show current contents of captured substrings
3239        \C-         do not supply a callout function
3240        \C!n        return 1 when callout number n is reached
3241        \C!n!m      return 1 when callout number n is reached for the mth time
3243    30. If pcregrep was called with the -l option and just a single file name, it
3244    output "<stdin>" if a match was found, instead of the file name.
3246    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3247    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3248    pcre_exec(). This saves a malloc/free per call. The default value of
3249    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3250    when configuring.
3252    32. The default maximum size of a compiled pattern is 64K. There have been a
3253    few cases of people hitting this limit. The code now uses macros to handle the
3254    storing of links as offsets within the compiled pattern. It defaults to 2-byte
3255    links, but this can be changed to 3 or 4 bytes by --with-link-size when
3256    configuring. Tests 2 and 5 work only with 2-byte links because they output
3257    debugging information about compiled patterns.
3259    33. Internal code re-arrangements:
3261    (a) Moved the debugging function for printing out a compiled regex into
3262        its own source file (printint.c) and used #include to pull it into
3263        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3264        separate copies.
3266    (b) Defined the list of op-code names for debugging as a macro in
3267        internal.h so that it is next to the definition of the opcodes.
3269    (c) Defined a table of op-code lengths for simpler skipping along compiled
3270        code. This is again a macro in internal.h so that it is next to the
3271        definition of the opcodes.
3273    34. Added support for recursive calls to individual subpatterns, along the
3274    lines of Robin Houston's patch (but implemented somewhat differently).
3276    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3277    allow it to read and process whole directories in Win32. This code was
3278    contributed by Lionel Fourquaux; it has not been tested by me.
3280    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3281    used to name a group. Names consist of alphanumerics and underscores, and must
3282    be unique. Back references use the syntax (?P=name) and recursive calls use
3283    (?P>name) which is a PCRE extension to the Python extension. Groups still have
3284    numbers. The function pcre_fullinfo() can be used after compilation to extract
3285    a name/number map. There are three relevant calls:
3287      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
3288      PCRE_INFO_NAMECOUNT            yields the number of entries
3289      PCRE_INFO_NAMETABLE            yields a pointer to the map.
3291    The map is a vector of fixed-size entries. The size of each entry depends on
3292    the length of the longest name used. The first two bytes of each entry are the
3293    group number, most significant byte first. There follows the corresponding
3294    name, zero terminated. The names are in alphabetical order.
3296    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3297    case instead of 255. Making it the same both with and without UTF-8 support
3298    means that the same test output works with both.
3300    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3301    calling malloc() with a zero argument.
3303    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3304    optimization. I've improved things by keeping a bitmap of backreferences with
3305    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3306    fact referenced, the optimization can be applied. It is unlikely that a
3307    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3308    the match to follow \n) will appear inside brackets with a number greater than
3309    31, but if it does, any back reference > 31 suppresses the optimization.
3311    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3312    of disabling numbered capturing parentheses. Any opening parenthesis that is
3313    not followed by ? behaves as if it were followed by ?: but named parentheses
3314    can still be used for capturing (and they will acquire numbers in the usual
3315    way).
3317    41. Redesigned the return codes from the match() function into yes/no/error so
3318    that errors can be passed back from deep inside the nested calls. A malloc
3319    failure while inside a recursive subpattern call now causes the
3320    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3322    42. It is now possible to set a limit on the number of times the match()
3323    function is called in a call to pcre_exec(). This facility makes it possible to
3324    limit the amount of recursion and backtracking, though not in a directly
3325    obvious way, because the match() function is used in a number of different
3326    circumstances. The count starts from zero for each position in the subject
3327    string (for non-anchored patterns). The default limit is, for compatibility, a
3328    large number, namely 10 000 000. You can change this in two ways:
3330    (a) When configuring PCRE before making, you can use --with-match-limit=n
3331        to set a default value for the compiled library.
3333    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3334        a different value is set. See 45 below.
3336    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3338    43. Added a new function pcre_config(int, void *) to enable run-time extraction
3339    of things that can be changed at compile time. The first argument specifies
3340    what is wanted and the second points to where the information is to be placed.
3341    The current list of available information is:
3343      PCRE_CONFIG_UTF8
3345    The output is an integer that is set to one if UTF-8 support is available;
3346    otherwise it is set to zero.
3350    The output is an integer that it set to the value of the code that is used for
3351    newline. It is either LF (10) or CR (13).
3355    The output is an integer that contains the number of bytes used for internal
3356    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3360    The output is an integer that contains the threshold above which the POSIX
3361    interface uses malloc() for output vectors. See item 31 above.
3365    The output is an unsigned integer that contains the default limit of the number
3366    of match() calls in a pcre_exec() execution. See 42 above.
3368    44. pcretest has been upgraded by the addition of the -C option. This causes it
3369    to extract all the available output from the new pcre_config() function, and to
3370    output it. The program then exits immediately.
3372    45. A need has arisen to pass over additional data with calls to pcre_exec() in
3373    order to support additional features. One way would have been to define
3374    pcre_exec2() (for example) with extra arguments, but this would not have been
3375    extensible, and would also have required all calls to the original function to
3376    be mapped to the new one. Instead, I have chosen to extend the mechanism that
3377    is used for passing in "extra" data from pcre_study().
3379    The pcre_extra structure is now exposed and defined in pcre.h. It currently
3380    contains the following fields:
3382      flags         a bitmap indicating which of the following fields are set
3383      study_data    opaque data from pcre_study()
3384      match_limit   a way of specifying a limit on match() calls for a specific
3385                      call to pcre_exec()
3386      callout_data  data for callouts (see 49 below)
3388    The flag bits are also defined in pcre.h, and are
3394    The pcre_study() function now returns one of these new pcre_extra blocks, with
3395    the actual study data pointed to by the study_data field, and the
3396    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3397    before. That is, this change is entirely upwards-compatible and requires no
3398    change to existing code.
3400    If you want to pass in additional data to pcre_exec(), you can either place it
3401    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3402    block.
3404    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3405    data string contains the escape sequence \M, pcretest calls pcre_exec() several
3406    times with different match limits, until it finds the minimum value needed for
3407    pcre_exec() to complete. The value is then output. This can be instructive; for
3408    most simple matches the number is quite small, but for pathological cases it
3409    gets very large very quickly.
3411    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3412    returns the size of the data block pointed to by the study_data field in a
3413    pcre_extra block, that is, the value that was passed as the argument to
3414    pcre_malloc() when PCRE was getting memory in which to place the information
3415    created by pcre_study(). The fourth argument should point to a size_t variable.
3416    pcretest has been extended so that this information is shown after a successful
3417    pcre_study() call when information about the compiled regex is being displayed.
3419    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3420    because what follows is always an absolute path. (Later: it turns out that this
3421    is more than cosmetic for MinGW, because it doesn't like empty path
3422    components.)
3424    49. Some changes have been made to the callout feature (see 28 above):
3426    (i)  A callout function now has three choices for what it returns:
3428           0  =>  success, carry on matching
3429         > 0  =>  failure at this point, but backtrack if possible
3430         < 0  =>  serious error, return this value from pcre_exec()
3432         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3433         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3434         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3435         use by callout functions. It will never be used by PCRE itself.
3437    (ii) The pcre_extra structure (see 45 above) has a void * field called
3438         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3439         pcre_callout_block structure has a field of the same name. The contents of
3440         the field passed in the pcre_extra structure are passed to the callout
3441         function in the corresponding field in the callout block. This makes it
3442         easier to use the same callout-containing regex from multiple threads. For
3443         testing, the pcretest program has a new data escape
3445           \C*n        pass the number n (may be negative) as callout_data
3447         If the callout function in pcretest receives a non-zero value as
3448         callout_data, it returns that value.
3450    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3451    there were some redundant $(CFLAGS) in commands that are now specified as
3452    $(LINK), which already includes $(CFLAGS).
3454    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3455    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3456    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3457    one-byte characters throughout. Note that case-insensitive matching applies
3458    only to characters whose values are less than 256. PCRE doesn't support the
3459    notion of cases for higher-valued characters.
3461    (i)   A character class whose characters are all within 0-255 is handled as
3462          a bit map, and the map is inverted for negative classes. Previously, a
3463          character > 255 always failed to match such a class; however it should
3464          match if the class was a negative one (e.g. [^ab]). This has been fixed.
3466    (ii)  A negated character class with a single character < 255 is coded as
3467          "not this character" (OP_NOT). This wasn't working properly when the test
3468          character was multibyte, either singly or repeated.
3470    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3471          mode, for example: \x{100}{2,3}.
3473    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3474          singly or repeated) now correctly test multibyte characters. However,
3475          PCRE doesn't recognize any characters with values greater than 255 as
3476          digits, spaces, or word characters. Such characters always match \D, \S,
3477          and \W, and never match \d, \s, or \w.
3479    (v)   Classes may now contain characters and character ranges with values
3480          greater than 255. For example: [ab\x{100}-\x{400}].
3482    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
3483          PCRE in UTF-8 mode.
3485    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3486    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3487    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3488    value.)
3490    53. The single man page has become too large. I have therefore split it up into
3491    a number of separate man pages. These also give rise to individual HTML pages;
3492    these are now put in a separate directory, and there is an index.html page that
3493    lists them all. Some hyperlinking between the pages has been installed.
3495    54. Added convenience functions for handling named capturing parentheses.
3497    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3498    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3499    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3500    are faulted.
3502    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3503    calling configure. These values are used when compiling the dftables.c program
3504    which is run to generate the source of the default character tables. They
3505    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3506    you will need to set these values.
3508    57. Updated the building process for Windows DLL, as provided by Fred Cox.
3511    Version 3.9 02-Jan-02
3512    ---------------------
3514    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3516    2. If --disable-static was given, the building process failed when trying to
3517    build pcretest and pcregrep. (For some reason it was using libtool to compile
3518    them, which is not right, as they aren't part of the library.)
3521    Version 3.8 18-Dec-01
3522    ---------------------
3524    1. The experimental UTF-8 code was completely screwed up. It was packing the
3525    bytes in the wrong order. How dumb can you get?
3528    Version 3.7 29-Oct-01
3529    ---------------------
3531    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3532    This caused pcretest, when used on the test data, to segfault. Unfortunately,
3533    this didn't happen under Solaris 8, where I normally test things.
3535    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3536    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3537    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3538    this fix an hour or so after the initial 3.7 release.)
3541    Version 3.6 23-Oct-01
3542    ---------------------
3544    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3545    offsets passed as NULL with zero offset count.
3547    2. The config.guess and config.sub files had not been updated when I moved to
3548    the latest autoconf.
3551    Version 3.5 15-Aug-01
3552    ---------------------
3554    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3555    had been forgotten.
3557    2. By using declared but undefined structures, we can avoid using "void"
3558    definitions in pcre.h while keeping the internal definitions of the structures
3559    private.
3561    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3562    user point of view, this means that both static and shared libraries are built
3563    by default, but this can be individually controlled. More of the work of
3564    handling this static/shared cases is now inside libtool instead of PCRE's make
3565    file.
3567    4. The pcretest utility is now installed along with pcregrep because it is
3568    useful for users (to test regexs) and by doing this, it automatically gets
3569    relinked by libtool. The documentation has been turned into a man page, so
3570    there are now .1, .txt, and .html versions in /doc.
3572    5. Upgrades to pcregrep:
3573       (i)   Added long-form option names like gnu grep.
3574       (ii)  Added --help to list all options with an explanatory phrase.
3575       (iii) Added -r, --recursive to recurse into sub-directories.
3576       (iv)  Added -f, --file to read patterns from a file.
3578    6. pcre_exec() was referring to its "code" argument before testing that
3579    argument for NULL (and giving an error if it was NULL).
3581    7. Upgraded Makefile.in to allow for compiling in a different directory from
3582    the source directory.
3584    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3585    options bits, the pointer it was passed was to an int instead of to an unsigned
3586    long int. This mattered only on 64-bit systems.
3588    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3589    generated) instead of pcre.in, which it its source. Also made the same change
3590    in several of the .c files.
3592    10. A new release of gcc defines printf() as a macro, which broke pcretest
3593    because it had an ifdef in the middle of a string argument for printf(). Fixed
3594    by using separate calls to printf().
3596    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3597    script, to force use of CR or LF instead of \n in the source. On non-Unix
3598    systems, the value can be set in config.h.
3600    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3601    absolute limit. Changed the text of the error message to make this clear, and
3602    likewise updated the man page.
3604    13. The limit of 99 on the number of capturing subpatterns has been removed.
3605    The new limit is 65535, which I hope will not be a "real" limit.
3608    Version 3.4 22-Aug-00
3609    ---------------------
3611    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3613    2. Diagnose condition (?(0) as an error instead of crashing on matching.
3616    Version 3.3 01-Aug-00
3617    ---------------------
3619    1. If an octal character was given, but the value was greater than \377, it
3620    was not g