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revision 11 by nigel, Sat Feb 24 21:38:17 2007 UTC revision 223 by ph10, Mon Aug 20 11:07:53 2007 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.3 20-Aug-07
5    ---------------------
6    
7     1. In the rejigging of the build system that eventually resulted in 7.1, the
8        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
9        brackets there is not right, since it causes compilers to look for an
10        installed pcre.h, not the version that is in the source that is being
11        compiled (which of course may be different). I have changed it back to:
12    
13          #include "pcre.h"
14    
15        I have a vague recollection that the change was concerned with compiling in
16        different directories, but in the new build system, that is taken care of
17        by the VPATH setting the Makefile.
18    
19     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
20        when the subject happened to end in the byte 0x85 (e.g. if the last
21        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
22        characters but of course it shouldn't be taken as a newline when it is part
23        of another character. The bug was that, for an unlimited repeat of . in
24        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
25        characters when looking for a newline.
26    
27     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
28    
29     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
30        in debug output.
31    
32     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
33        long printing in the pcrecpp unittest when running under MinGW.
34    
35     6. ESC_K was left out of the EBCDIC table.
36    
37     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
38        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
39        limit also applies to "virtual nesting" when a pattern is recursive, and in
40        this case 1000 isn't so big. I have been able to remove this limit at the
41        expense of backing off one optimization in certain circumstances. Normally,
42        when pcre_exec() would call its internal match() function recursively and
43        immediately return the result unconditionally, it uses a "tail recursion"
44        feature to save stack. However, when a subpattern that can match an empty
45        string has an unlimited repetition quantifier, it no longer makes this
46        optimization. That gives it a stack frame in which to save the data for
47        checking that an empty string has been matched. Previously this was taken
48        from the 1000-entry workspace that had been reserved. So now there is no
49        explicit limit, but more stack is used.
50    
51     8. Applied Daniel's patches to solve problems with the import/export magic
52        syntax that is required for Windows, and which was going wrong for the
53        pcreposix and pcrecpp parts of the library. These were overlooked when this
54        problem was solved for the main library.
55    
56     9. There were some crude static tests to avoid integer overflow when computing
57        the size of patterns that contain repeated groups with explicit upper
58        limits. As the maximum quantifier is 65535, the maximum group length was
59        set at 30,000 so that the product of these two numbers did not overflow a
60        32-bit integer. However, it turns out that people want to use groups that
61        are longer than 30,000 bytes (though not repeat them that many times).
62        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
63        made it possible to implement the integer overflow checks in a much more
64        dynamic way, which I have now done. The artificial limitation on group
65        length has been removed - we now have only the limit on the total length of
66        the compiled pattern, which depends on the LINK_SIZE setting.
67    
68    10. Fixed a bug in the documentation for get/copy named substring when
69        duplicate names are permitted. If none of the named substrings are set, the
70        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
71        empty string.
72    
73    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
74        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
75        because the ] is interpreted as the first data character and the
76        terminating ] is not found. PCRE has been made compatible with Perl in this
77        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
78        cause memory overwriting.
79    
80    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
81        string has been matched (to stop an infinite loop). It was not recognizing
82        a conditional subpattern that could match an empty string if that
83        subpattern was within another subpattern. For example, it looped when
84        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
85        condition was not nested. This bug has been fixed.
86    
87    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
88        past the start of the subject in the presence of bytes with the top bit
89        set, for example "\x8aBCD".
90    
91    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
92        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
93    
94    14. Optimized (?!) to (*FAIL).
95    
96    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
97        This restricts code points to be within the range 0 to 0x10FFFF, excluding
98        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
99        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
100        does: it's just the validity check that is more restrictive.
101    
102    16. Inserted checks for integer overflows during escape sequence (backslash)
103        processing, and also fixed erroneous offset values for syntax errors during
104        backslash processing.
105    
106    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
107        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
108    
109    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
110        caused an overrun.
111    
112    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
113        something other than just ASCII characters) inside a group that had an
114        unlimited repeat caused a loop at compile time (while checking to see
115        whether the group could match an empty string).
116    
117    20. Debugging a pattern containing \p or \P could cause a crash. For example,
118        [\P{Any}] did so. (Error in the code for printing property names.)
119    
120    21. An orphan \E inside a character class could cause a crash.
121    
122    22. A repeated capturing bracket such as (A)? could cause a wild memory
123        reference during compilation.
124    
125    23. There are several functions in pcre_compile() that scan along a compiled
126        expression for various reasons (e.g. to see if it's fixed length for look
127        behind). There were bugs in these functions when a repeated \p or \P was
128        present in the pattern. These operators have additional parameters compared
129        with \d, etc, and these were not being taken into account when moving along
130        the compiled data. Specifically:
131    
132        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
133            length.
134    
135        (b) An item such as \pL+ within a repeated group could cause crashes or
136            loops.
137    
138        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
139            "reference to non-existent subpattern" error.
140    
141        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
142    
143    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
144        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
145    
146    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
147    
148    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
149        character were causing crashes (broken optimization).
150    
151    
152    Version 7.2 19-Jun-07
153    ---------------------
154    
155     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
156        which is apparently normally available under Windows.
157    
158     2. Re-jig the pcregrep tests with different newline settings in an attempt
159        to make them independent of the local environment's newline setting.
160    
161     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
162    
163     4. Some of the "internals" tests were previously cut out when the link size
164        was not 2, because the output contained actual offsets. The recent new
165        "Z" feature of pcretest means that these can be cut out, making the tests
166        usable with all link sizes.
167    
168     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
169        stack recursion. This gives a massive performance boost under BSD, but just
170        a small improvement under Linux. However, it saves one field in the frame
171        in all cases.
172    
173     6. Added more features from the forthcoming Perl 5.10:
174    
175        (a) (?-n) (where n is a string of digits) is a relative subroutine or
176            recursion call. It refers to the nth most recently opened parentheses.
177    
178        (b) (?+n) is also a relative subroutine call; it refers to the nth next
179            to be opened parentheses.
180    
181        (c) Conditions that refer to capturing parentheses can be specified
182            relatively, for example, (?(-2)... or (?(+3)...
183    
184        (d) \K resets the start of the current match so that everything before
185            is not part of it.
186    
187        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
188    
189        (f) \g{name} is another synonym - part of Perl 5.10's unification of
190            reference syntax.
191    
192        (g) (?| introduces a group in which the numbering of parentheses in each
193            alternative starts with the same number.
194    
195        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
196    
197     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
198        PCRE_INFO_JCHANGED.
199    
200     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
201        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
202        for detecting groups that can match an empty string.
203    
204     9. A pattern with a very large number of alternatives (more than several
205        hundred) was running out of internal workspace during the pre-compile
206        phase, where pcre_compile() figures out how much memory will be needed. A
207        bit of new cunning has reduced the workspace needed for groups with
208        alternatives. The 1000-alternative test pattern now uses 12 bytes of
209        workspace instead of running out of the 4096 that are available.
210    
211    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
212    
213    11. Applied patch from Google to remove an optimization that didn't quite work.
214        The report of the bug said:
215    
216          pcrecpp::RE("a*").FullMatch("aaa") matches, while
217          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
218          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
219    
220    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
221        it matched the wrong number of bytes.
222    
223    
224    Version 7.1 24-Apr-07
225    ---------------------
226    
227     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
228        that is more "standard", making use of automake and other Autotools. There
229        is some re-arrangement of the files and adjustment of comments consequent
230        on this.
231    
232     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
233        for recursive directory scanning broke on some systems because the files
234        are not scanned in any specific order and on different systems the order
235        was different. A call to "sort" has been inserted into RunGrepTest for the
236        approprate test as a short-term fix. In the longer term there may be an
237        alternative.
238    
239     3. I had an email from Eric Raymond about problems translating some of PCRE's
240        man pages to HTML (despite the fact that I distribute HTML pages, some
241        people do their own conversions for various reasons). The problems
242        concerned the use of low-level troff macros .br and .in. I have therefore
243        removed all such uses from the man pages (some were redundant, some could
244        be replaced by .nf/.fi pairs). The 132html script that I use to generate
245        HTML has been updated to handle .nf/.fi and to complain if it encounters
246        .br or .in.
247    
248     4. Updated comments in configure.ac that get placed in config.h.in and also
249        arranged for config.h to be included in the distribution, with the name
250        config.h.generic, for the benefit of those who have to compile without
251        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
252    
253     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
254        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
255        makevp.bat for the current PCRE, using the additional files
256        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
257    
258     6. A Windows user reported a minor discrepancy with test 2, which turned out
259        to be caused by a trailing space on an input line that had got lost in his
260        copy. The trailing space was an accident, so I've just removed it.
261    
262     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
263        that is needed.
264    
265     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
266        as "const" (a) because they are and (b) because it helps the PHP
267        maintainers who have recently made a script to detect big data structures
268        in the php code that should be moved to the .rodata section. I remembered
269        to update Builducptable as well, so it won't revert if ucptable.h is ever
270        re-created.
271    
272     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
273        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
274        order to be able to cut out the UTF-8 tables in the latter when UTF-8
275        support is not required. This saves 1.5-2K of code, which is important in
276        some applications.
277    
278        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
279        so as not to refer to the tables, even though these functions will never be
280        called when UTF-8 support is disabled. Otherwise there are problems with a
281        shared library.
282    
283    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
284    
285        (a) It was defining its arguments as char * instead of void *.
286    
287        (b) It was assuming that all moves were upwards in memory; this was true
288            a long time ago when I wrote it, but is no longer the case.
289    
290        The emulated memove() is provided for those environments that have neither
291        memmove() nor bcopy(). I didn't think anyone used it these days, but that
292        is clearly not the case, as these two bugs were recently reported.
293    
294    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
295        and Detrail to create the HTML documentation, the .txt form of the man
296        pages, and it removes trailing spaces from listed files. It also creates
297        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
298        case, it wraps all the #defines with #ifndefs. This script should be run
299        before "make dist".
300    
301    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
302        with Unicode property support.
303    
304        (a) For a maximizing quantifier, if the two different cases of the
305            character were of different lengths in their UTF-8 codings (there are
306            some cases like this - I found 11), and the matching function had to
307            back up over a mixture of the two cases, it incorrectly assumed they
308            were both the same length.
309    
310        (b) When PCRE was configured to use the heap rather than the stack for
311            recursion during matching, it was not correctly preserving the data for
312            the other case of a UTF-8 character when checking ahead for a match
313            while processing a minimizing repeat. If the check also involved
314            matching a wide character, but failed, corruption could cause an
315            erroneous result when trying to check for a repeat of the original
316            character.
317    
318    13. Some tidying changes to the testing mechanism:
319    
320        (a) The RunTest script now detects the internal link size and whether there
321            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
322            values substituted by "configure". (The RunGrepTest script already did
323            this for UTF-8.) The configure.ac script no longer substitutes the
324            relevant variables.
325    
326        (b) The debugging options /B and /D in pcretest show the compiled bytecode
327            with length and offset values. This means that the output is different
328            for different internal link sizes. Test 2 is skipped for link sizes
329            other than 2 because of this, bypassing the problem. Unfortunately,
330            there was also a test in test 3 (the locale tests) that used /B and
331            failed for link sizes other than 2. Rather than cut the whole test out,
332            I have added a new /Z option to pcretest that replaces the length and
333            offset values with spaces. This is now used to make test 3 independent
334            of link size. (Test 2 will be tidied up later.)
335    
336    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
337        segmentation fault instead of returning the appropriate error message.
338    
339    15. In multiline mode when the newline sequence was set to "any", the pattern
340        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
341        This doesn't seem right; it now treats the CRLF combination as the line
342        ending, and so does not match in that case. It's only a pattern such as ^$
343        that would hit this one: something like ^ABC$ would have failed after \r
344        and then tried again after \r\n.
345    
346    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
347        in an attempt to make files that differ only in their line terminators
348        compare equal. This works on Linux.
349    
350    17. Under certain error circumstances pcregrep might try to free random memory
351        as it exited. This is now fixed, thanks to valgrind.
352    
353    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
354        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
355        was because its rules for how to advance for /g after matching an empty
356        string at the end of a line did not allow for this case. They now check for
357        it specially.
358    
359    20. pcretest is supposed to handle patterns and data of any length, by
360        extending its buffers when necessary. It was getting this wrong when the
361        buffer for a data line had to be extended.
362    
363    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
364        CRLF as a newline sequence.
365    
366    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
367        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
368        I have nevertheless tidied it up.
369    
370    23. Added some casts to kill warnings from HP-UX ia64 compiler.
371    
372    24. Added a man page for pcre-config.
373    
374    
375    Version 7.0 19-Dec-06
376    ---------------------
377    
378     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
379        moving to gcc 4.1.1.
380    
381     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
382        sys/time.h, which is documented as needed for this function. It doesn't
383        seem to matter on Linux, but it showed up on some releases of OS X.
384    
385     3. It seems that there are systems where bytes whose values are greater than
386        127 match isprint() in the "C" locale. The "C" locale should be the
387        default when a C program starts up. In most systems, only ASCII printing
388        characters match isprint(). This difference caused the output from pcretest
389        to vary, making some of the tests fail. I have changed pcretest so that:
390    
391        (a) When it is outputting text in the compiled version of a pattern, bytes
392            other than 32-126 are always shown as hex escapes.
393    
394        (b) When it is outputting text that is a matched part of a subject string,
395            it does the same, unless a different locale has been set for the match
396            (using the /L modifier). In this case, it uses isprint() to decide.
397    
398     4. Fixed a major bug that caused incorrect computation of the amount of memory
399        required for a compiled pattern when options that changed within the
400        pattern affected the logic of the preliminary scan that determines the
401        length. The relevant options are -x, and -i in UTF-8 mode. The result was
402        that the computed length was too small. The symptoms of this bug were
403        either the PCRE error "internal error: code overflow" from pcre_compile(),
404        or a glibc crash with a message such as "pcretest: free(): invalid next
405        size (fast)". Examples of patterns that provoked this bug (shown in
406        pcretest format) are:
407    
408          /(?-x: )/x
409          /(?x)(?-x: \s*#\s*)/
410          /((?i)[\x{c0}])/8
411          /(?i:[\x{c0}])/8
412    
413        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
414        is now done differently.
415    
416     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
417        wrapper classes; (b) implement a new function in the C++ scanner that is
418        more efficient than the old way of doing things because it avoids levels of
419        recursion in the regex matching; (c) add a paragraph to the documentation
420        for the FullMatch() function.
421    
422     6. The escape sequence \n was being treated as whatever was defined as
423        "newline". Not only was this contrary to the documentation, which states
424        that \n is character 10 (hex 0A), but it also went horribly wrong when
425        "newline" was defined as CRLF. This has been fixed.
426    
427     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
428        was being set to -1 for the "end of line" case (supposedly a value that no
429        character can have). Though this value is never used (the check for end of
430        line is "zero bytes in current character"), it caused compiler complaints.
431        I've changed it to 0xffffffff.
432    
433     8. In pcre_version.c, the version string was being built by a sequence of
434        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
435        string (as it is for production releases) called a macro with an empty
436        argument. The C standard says the result of this is undefined. The gcc
437        compiler treats it as an empty string (which was what was wanted) but it is
438        reported that Visual C gives an error. The source has been hacked around to
439        avoid this problem.
440    
441     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
442        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
443        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
444        of them did).
445    
446    10. Originally, pcretest opened its input and output without "b"; then I was
447        told that "b" was needed in some environments, so it was added for release
448        5.0 to both the input and output. (It makes no difference on Unix-like
449        systems.) Later I was told that it is wrong for the input on Windows. I've
450        now abstracted the modes into two macros, to make it easier to fiddle with
451        them, and removed "b" from the input mode under Windows.
452    
453    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
454    
455    12. Added -help and --help to pcretest as an official way of being reminded
456        of the options.
457    
458    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
459        and pcrecpp.cc because they annoy compilers at high warning levels.
460    
461    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
462    
463    15. Fixed an occurrence of == in configure.ac that should have been = (shell
464        scripts are not C programs :-) and which was not noticed because it works
465        on Linux.
466    
467    16. pcretest is supposed to handle any length of pattern and data line (as one
468        line or as a continued sequence of lines) by extending its input buffer if
469        necessary. This feature was broken for very long pattern lines, leading to
470        a string of junk being passed to pcre_compile() if the pattern was longer
471        than about 50K.
472    
473    17. I have done a major re-factoring of the way pcre_compile() computes the
474        amount of memory needed for a compiled pattern. Previously, there was code
475        that made a preliminary scan of the pattern in order to do this. That was
476        OK when PCRE was new, but as the facilities have expanded, it has become
477        harder and harder to keep it in step with the real compile phase, and there
478        have been a number of bugs (see for example, 4 above). I have now found a
479        cunning way of running the real compile function in a "fake" mode that
480        enables it to compute how much memory it would need, while actually only
481        ever using a few hundred bytes of working memory and without too many
482        tests of the mode. This should make future maintenance and development
483        easier. A side effect of this work is that the limit of 200 on the nesting
484        depth of parentheses has been removed (though this was never a serious
485        limitation, I suspect). However, there is a downside: pcre_compile() now
486        runs more slowly than before (30% or more, depending on the pattern). I
487        hope this isn't a big issue. There is no effect on runtime performance.
488    
489    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
490        newline (only possible for the last line of a file) and it was a
491        pattern that set a locale (followed by /Lsomething), pcretest crashed.
492    
493    19. Added additional timing features to pcretest. (1) The -tm option now times
494        matching only, not compiling. (2) Both -t and -tm can be followed, as a
495        separate command line item, by a number that specifies the number of
496        repeats to use when timing. The default is 50000; this gives better
497        precision, but takes uncomfortably long for very large patterns.
498    
499    20. Extended pcre_study() to be more clever in cases where a branch of a
500        subpattern has no definite first character. For example, (a*|b*)[cd] would
501        previously give no result from pcre_study(). Now it recognizes that the
502        first character must be a, b, c, or d.
503    
504    21. There was an incorrect error "recursive call could loop indefinitely" if
505        a subpattern (or the entire pattern) that was being tested for matching an
506        empty string contained only one non-empty item after a nested subpattern.
507        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
508        incorrectly, because the \d was being skipped in the check.
509    
510    22. The pcretest program now has a new pattern option /B and a command line
511        option -b, which is equivalent to adding /B to every pattern. This causes
512        it to show the compiled bytecode, without the additional information that
513        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
514        is the same as /B/I).
515    
516    23. A new optimization is now able automatically to treat some sequences such
517        as a*b as a*+b. More specifically, if something simple (such as a character
518        or a simple class like \d) has an unlimited quantifier, and is followed by
519        something that cannot possibly match the quantified thing, the quantifier
520        is automatically "possessified".
521    
522    24. A recursive reference to a subpattern whose number was greater than 39
523        went wrong under certain circumstances in UTF-8 mode. This bug could also
524        have affected the operation of pcre_study().
525    
526    25. Realized that a little bit of performance could be had by replacing
527        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
528    
529    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
530    
531    27. Possessive quantifiers such as a++ were previously implemented by turning
532        them into atomic groups such as ($>a+). Now they have their own opcodes,
533        which improves performance. This includes the automatically created ones
534        from 23 above.
535    
536    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
537        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
538        the first matched character to be a colon. This applied both to named and
539        numbered groups.
540    
541    29. The ucpinternal.h header file was missing its idempotency #ifdef.
542    
543    30. I was sent a "project" file called libpcre.a.dev which I understand makes
544        building PCRE on Windows easier, so I have included it in the distribution.
545    
546    31. There is now a check in pcretest against a ridiculously large number being
547        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
548        loop, the loop is abandoned.
549    
550    32. Forward references to subpatterns in conditions such as (?(2)...) where
551        subpattern 2 is defined later cause pcre_compile() to search forwards in
552        the pattern for the relevant set of parentheses. This search went wrong
553        when there were unescaped parentheses in a character class, parentheses
554        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
555    
556    33. "Subroutine" calls and backreferences were previously restricted to
557        referencing subpatterns earlier in the regex. This restriction has now
558        been removed.
559    
560    34. Added a number of extra features that are going to be in Perl 5.10. On the
561        whole, these are just syntactic alternatives for features that PCRE had
562        previously implemented using the Python syntax or my own invention. The
563        other formats are all retained for compatibility.
564    
565        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
566            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
567            also .NET compatible.
568    
569        (b) A recursion or subroutine call to a named group can now be defined as
570            (?&name) as well as (?P>name).
571    
572        (c) A backreference to a named group can now be defined as \k<name> or
573            \k'name' as well as (?P=name). The new forms, as well as being in Perl
574            5.10, are also .NET compatible.
575    
576        (d) A conditional reference to a named group can now use the syntax
577            (?(<name>) or (?('name') as well as (?(name).
578    
579        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
580            groups (named and numbered) that are never evaluated inline, but can be
581            called as "subroutines" from elsewhere. In effect, the DEFINE condition
582            is always false. There may be only one alternative in such a group.
583    
584        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
585            as the simple (?(R). The condition is true only if the most recent
586            recursion is that of the given number or name. It does not search out
587            through the entire recursion stack.
588    
589        (g) The escape \gN or \g{N} has been added, where N is a positive or
590            negative number, specifying an absolute or relative reference.
591    
592    35. Tidied to get rid of some further signed/unsigned compiler warnings and
593        some "unreachable code" warnings.
594    
595    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
596        things, this adds five new scripts.
597    
598    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
599        There were also incompatibilities regarding the handling of \Q..\E inside
600        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
601        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
602    
603    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
604        matches an empty string, and forcibly breaks the loop. There were bugs in
605        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
606        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
607        separate and independent bugs (that affected different cases) have been
608        fixed.
609    
610    39. Refactored the code to abolish the use of different opcodes for small
611        capturing bracket numbers. This is a tidy that I avoided doing when I
612        removed the limit on the number of capturing brackets for 3.5 back in 2001.
613        The new approach is not only tidier, it makes it possible to reduce the
614        memory needed to fix the previous bug (38).
615    
616    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
617        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
618        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
619        mode.
620    
621    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
622        report.
623    
624    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
625        copy construction and assignment in the C++ wrapper.
626    
627    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
628        couple of bugs that could have given wrong results in the "--newline=crlf"
629        case.
630    
631    44. Added a number of casts and did some reorganization of signed/unsigned int
632        variables following suggestions from Dair Grant. Also renamed the variable
633        "this" as "item" because it is a C++ keyword.
634    
635    45. Arranged for dftables to add
636    
637          #include "pcre_internal.h"
638    
639        to pcre_chartables.c because without it, gcc 4.x may remove the array
640        definition from the final binary if PCRE is built into a static library and
641        dead code stripping is activated.
642    
643    46. For an unanchored pattern, if a match attempt fails at the start of a
644        newline sequence, and the newline setting is CRLF or ANY, and the next two
645        characters are CRLF, advance by two characters instead of one.
646    
647    
648    Version 6.7 04-Jul-06
649    ---------------------
650    
651     1. In order to handle tests when input lines are enormously long, pcretest has
652        been re-factored so that it automatically extends its buffers when
653        necessary. The code is crude, but this _is_ just a test program. The
654        default size has been increased from 32K to 50K.
655    
656     2. The code in pcre_study() was using the value of the re argument before
657        testing it for NULL. (Of course, in any sensible call of the function, it
658        won't be NULL.)
659    
660     3. The memmove() emulation function in pcre_internal.h, which is used on
661        systems that lack both memmove() and bcopy() - that is, hardly ever -
662        was missing a "static" storage class specifier.
663    
664     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
665        containing an extended class (one that cannot be represented by a bitmap
666        because it contains high-valued characters or Unicode property items, e.g.
667        [\pZ]). Almost always one would set UTF-8 mode when processing such a
668        pattern, but PCRE should not loop if you do not (it no longer does).
669        [Detail: two cases were found: (a) a repeated subpattern containing an
670        extended class; (b) a recursive reference to a subpattern that followed a
671        previous extended class. It wasn't skipping over the extended class
672        correctly when UTF-8 mode was not set.]
673    
674     5. A negated single-character class was not being recognized as fixed-length
675        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
676        compile error "lookbehind assertion is not fixed length".
677    
678     6. The RunPerlTest auxiliary script was showing an unexpected difference
679        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
680        write a Perl script that can interpret lines of an input file either as
681        byte characters or as UTF-8, which is what "perltest" was being required to
682        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
683        can't do is switch easily at run time between having the "use utf8;" pragma
684        or not. In the end, I fudged it by using the RunPerlTest script to insert
685        "use utf8;" explicitly for the UTF-8 tests.
686    
687     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
688        the end of the subject string, contrary to the documentation and to what
689        Perl does. This was true of both matching functions. Now it matches only at
690        the start of the subject and immediately after *internal* newlines.
691    
692     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
693        a pointer to an int instead of a pointer to an unsigned long int. This
694        caused problems on 64-bit systems.
695    
696     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
697        instance of the 'standard' template library not being so standard".
698    
699    10. There was no check on the number of named subpatterns nor the maximum
700        length of a subpattern name. The product of these values is used to compute
701        the size of the memory block for a compiled pattern. By supplying a very
702        long subpattern name and a large number of named subpatterns, the size
703        computation could be caused to overflow. This is now prevented by limiting
704        the length of names to 32 characters, and the number of named subpatterns
705        to 10,000.
706    
707    11. Subpatterns that are repeated with specific counts have to be replicated in
708        the compiled pattern. The size of memory for this was computed from the
709        length of the subpattern and the repeat count. The latter is limited to
710        65535, but there was no limit on the former, meaning that integer overflow
711        could in principle occur. The compiled length of a repeated subpattern is
712        now limited to 30,000 bytes in order to prevent this.
713    
714    12. Added the optional facility to have named substrings with the same name.
715    
716    13. Added the ability to use a named substring as a condition, using the
717        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
718        are numbers (not recommended). Forward references are permitted.
719    
720    14. Added forward references in named backreferences (if you see what I mean).
721    
722    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
723        pattern could run off the end of the subject. For example, the pattern
724        "(?s)(.{1,5})"8 did this with the subject "ab".
725    
726    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
727        PCRE_CASELESS was set when matching characters that were quantified with ?
728        or *.
729    
730    17. A character class other than a single negated character that had a minimum
731        but no maximum quantifier - for example [ab]{6,} - was not handled
732        correctly by pce_dfa_exec(). It would match only one character.
733    
734    18. A valid (though odd) pattern that looked like a POSIX character
735        class but used an invalid character after [ (for example [[,abc,]]) caused
736        pcre_compile() to give the error "Failed: internal error: code overflow" or
737        in some cases to crash with a glibc free() error. This could even happen if
738        the pattern terminated after [[ but there just happened to be a sequence of
739        letters, a binary zero, and a closing ] in the memory that followed.
740    
741    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
742        over the years. Originally (before any Unicode support), just the bottom 8
743        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
744        output from "man perlunicode" includes this:
745    
746          The regular expression compiler produces polymorphic opcodes.  That
747          is, the pattern adapts to the data and automatically switches to
748          the Unicode character scheme when presented with Unicode data--or
749          instead uses a traditional byte scheme when presented with byte
750          data.
751    
752        Sadly, a wide octal escape does not cause a switch, and in a string with
753        no other multibyte characters, these octal escapes are treated as before.
754        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
755        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
756        Unicode string.
757    
758        I have not perpetrated such confusion in PCRE. Up till now, it took just
759        the bottom 8 bits, as in old Perl. I have now made octal escapes with
760        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
761        translate to the appropriate multibyte character.
762    
763    29. Applied some refactoring to reduce the number of warnings from Microsoft
764        and Borland compilers. This has included removing the fudge introduced
765        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
766        a warning about an unused variable.
767    
768    21. PCRE has not included VT (character 0x0b) in the set of whitespace
769        characters since release 4.0, because Perl (from release 5.004) does not.
770        [Or at least, is documented not to: some releases seem to be in conflict
771        with the documentation.] However, when a pattern was studied with
772        pcre_study() and all its branches started with \s, PCRE still included VT
773        as a possible starting character. Of course, this did no harm; it just
774        caused an unnecessary match attempt.
775    
776    22. Removed a now-redundant internal flag bit that recorded the fact that case
777        dependency changed within the pattern. This was once needed for "required
778        byte" processing, but is no longer used. This recovers a now-scarce options
779        bit. Also moved the least significant internal flag bit to the most-
780        significant bit of the word, which was not previously used (hangover from
781        the days when it was an int rather than a uint) to free up another bit for
782        the future.
783    
784    23. Added support for CRLF line endings as well as CR and LF. As well as the
785        default being selectable at build time, it can now be changed at runtime
786        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
787        specify that it is scanning data with non-default line endings.
788    
789    24. Changed the definition of CXXLINK to make it agree with the definition of
790        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
791    
792    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
793        recursions. This makes a big different to stack usage for some patterns.
794    
795    26. If a subpattern containing a named recursion or subroutine reference such
796        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
797        the space required for the compiled pattern went wrong and gave too small a
798        value. Depending on the environment, this could lead to "Failed: internal
799        error: code overflow at offset 49" or "glibc detected double free or
800        corruption" errors.
801    
802    27. Applied patches from Google (a) to support the new newline modes and (b) to
803        advance over multibyte UTF-8 characters in GlobalReplace.
804    
805    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
806        difference for some implementation of PCRE in some Windows version.
807    
808    29. Added some extra testing facilities to pcretest:
809    
810        \q<number>   in a data line sets the "match limit" value
811        \Q<number>   in a data line sets the "match recursion limt" value
812        -S <number>  sets the stack size, where <number> is in megabytes
813    
814        The -S option isn't available for Windows.
815    
816    
817    Version 6.6 06-Feb-06
818    ---------------------
819    
820     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
821        in pcreposix.h. I have copied the definition from pcre.h.
822    
823     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
824        because pcre.h is no longer a built file.
825    
826     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
827        not normally included in the compiled code.
828    
829    
830    Version 6.5 01-Feb-06
831    ---------------------
832    
833     1. When using the partial match feature with pcre_dfa_exec(), it was not
834        anchoring the second and subsequent partial matches at the new starting
835        point. This could lead to incorrect results. For example, with the pattern
836        /1234/, partially matching against "123" and then "a4" gave a match.
837    
838     2. Changes to pcregrep:
839    
840        (a) All non-match returns from pcre_exec() were being treated as failures
841            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
842            error message is output. Some extra information is given for the
843            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
844            probably the only errors that are likely to be caused by users (by
845            specifying a regex that has nested indefinite repeats, for instance).
846            If there are more than 20 of these errors, pcregrep is abandoned.
847    
848        (b) A binary zero was treated as data while matching, but terminated the
849            output line if it was written out. This has been fixed: binary zeroes
850            are now no different to any other data bytes.
851    
852        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
853            used to set a locale for matching. The --locale=xxxx long option has
854            been added (no short equivalent) to specify a locale explicitly on the
855            pcregrep command, overriding the environment variables.
856    
857        (d) When -B was used with -n, some line numbers in the output were one less
858            than they should have been.
859    
860        (e) Added the -o (--only-matching) option.
861    
862        (f) If -A or -C was used with -c (count only), some lines of context were
863            accidentally printed for the final match.
864    
865        (g) Added the -H (--with-filename) option.
866    
867        (h) The combination of options -rh failed to suppress file names for files
868            that were found from directory arguments.
869    
870        (i) Added the -D (--devices) and -d (--directories) options.
871    
872        (j) Added the -F (--fixed-strings) option.
873    
874        (k) Allow "-" to be used as a file name for -f as well as for a data file.
875    
876        (l) Added the --colo(u)r option.
877    
878        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
879            is not present by default.
880    
881     3. A nasty bug was discovered in the handling of recursive patterns, that is,
882        items such as (?R) or (?1), when the recursion could match a number of
883        alternatives. If it matched one of the alternatives, but subsequently,
884        outside the recursion, there was a failure, the code tried to back up into
885        the recursion. However, because of the way PCRE is implemented, this is not
886        possible, and the result was an incorrect result from the match.
887    
888        In order to prevent this happening, the specification of recursion has
889        been changed so that all such subpatterns are automatically treated as
890        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
891    
892     4. I had overlooked the fact that, in some locales, there are characters for
893        which isalpha() is true but neither isupper() nor islower() are true. In
894        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
895        and ordfeminine) are like this. This affected the treatment of \w and \W
896        when they appeared in character classes, but not when they appeared outside
897        a character class. The bit map for "word" characters is now created
898        separately from the results of isalnum() instead of just taking it from the
899        upper, lower, and digit maps. (Plus the underscore character, of course.)
900    
901     5. The above bug also affected the handling of POSIX character classes such as
902        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
903        permanent tables. Instead, the bit maps for such a class were previously
904        created as the appropriate unions of the upper, lower, and digit bitmaps.
905        Now they are created by subtraction from the [[:word:]] class, which has
906        its own bitmap.
907    
908     6. The [[:blank:]] character class matches horizontal, but not vertical space.
909        It is created by subtracting the vertical space characters (\x09, \x0a,
910        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
911        subtraction was done in the overall bitmap for a character class, meaning
912        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
913        be recognized. This bug has been fixed.
914    
915     7. Patches from the folks at Google:
916    
917          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
918          real life, but is still worth protecting against".
919    
920          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
921          regular expressions".
922    
923          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
924          have it.
925    
926          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
927          "configure" and the latter not, in order to fix a problem somebody had
928          with compiling the Arg class on HP-UX.
929    
930          (e) Improve the error-handling of the C++ wrapper a little bit.
931    
932          (f) New tests for checking recursion limiting.
933    
934     8. The pcre_memmove() function, which is used only if the environment does not
935        have a standard memmove() function (and is therefore rarely compiled),
936        contained two bugs: (a) use of int instead of size_t, and (b) it was not
937        returning a result (though PCRE never actually uses the result).
938    
939     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
940        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
941        returned instead of calling malloc() with an overflowing number that would
942        most likely cause subsequent chaos.
943    
944    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
945    
946    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
947        with this option is matched, the nmatch and pmatch options of regexec() are
948        ignored.
949    
950    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
951        provided in case anyone wants to the the POSIX interface with UTF-8
952        strings.
953    
954    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
955        C++ linking (needed for some HP-UX environments).
956    
957    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
958        (unused parameter) and in the pcre_printint() function (omitted "default"
959        switch label when the default is to do nothing).
960    
961    15. Added some code to make it possible, when PCRE is compiled as a C++
962        library, to replace subject pointers for pcre_exec() with a smart pointer
963        class, thus making it possible to process discontinuous strings.
964    
965    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
966        much the same function. They were added by different people who were trying
967        to make PCRE easy to compile on non-Unix systems. It has been suggested
968        that PCRE_EXPORT be abolished now that there is more automatic apparatus
969        for compiling on Windows systems. I have therefore replaced it with
970        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
971        defaults to "extern" for C or "extern C" for C++, which works fine on
972        Unix-like systems. It is now possible to override the value of PCRE_DATA_
973        SCOPE with something explicit in config.h. In addition:
974    
975        (a) pcreposix.h still had just "extern" instead of either of these macros;
976            I have replaced it with PCRE_DATA_SCOPE.
977    
978        (b) Functions such as _pcre_xclass(), which are internal to the library,
979            but external in the C sense, all had PCRE_EXPORT in their definitions.
980            This is apparently wrong for the Windows case, so I have removed it.
981            (It makes no difference on Unix-like systems.)
982    
983    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
984        of recursive calls to match(). This is different to MATCH_LIMIT because
985        that limits the total number of calls to match(), not all of which increase
986        the depth of recursion. Limiting the recursion depth limits the amount of
987        stack (or heap if NO_RECURSE is set) that is used. The default can be set
988        when PCRE is compiled, and changed at run time. A patch from Google adds
989        this functionality to the C++ interface.
990    
991    18. Changes to the handling of Unicode character properties:
992    
993        (a) Updated the table to Unicode 4.1.0.
994    
995        (b) Recognize characters that are not in the table as "Cn" (undefined).
996    
997        (c) I revised the way the table is implemented to a much improved format
998            which includes recognition of ranges. It now supports the ranges that
999            are defined in UnicodeData.txt, and it also amalgamates other
1000            characters into ranges. This has reduced the number of entries in the
1001            table from around 16,000 to around 3,000, thus reducing its size
1002            considerably. I realized I did not need to use a tree structure after
1003            all - a binary chop search is just as efficient. Having reduced the
1004            number of entries, I extended their size from 6 bytes to 8 bytes to
1005            allow for more data.
1006    
1007        (d) Added support for Unicode script names via properties such as \p{Han}.
1008    
1009    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1010        matching that character.
1011    
1012    20. When matching a repeated Unicode property with a minimum greater than zero,
1013        (for example \pL{2,}), PCRE could look past the end of the subject if it
1014        reached it while seeking the minimum number of characters. This could
1015        happen only if some of the characters were more than one byte long, because
1016        there is a check for at least the minimum number of bytes.
1017    
1018    21. Refactored the implementation of \p and \P so as to be more general, to
1019        allow for more different types of property in future. This has changed the
1020        compiled form incompatibly. Anybody with saved compiled patterns that use
1021        \p or \P will have to recompile them.
1022    
1023    22. Added "Any" and "L&" to the supported property types.
1024    
1025    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1026        but give a compile time error if the value is greater than 0xff.
1027    
1028    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1029        accidentally not being installed or uninstalled.
1030    
1031    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1032        made were to insert the current release number. This seemed silly, because
1033        it made things harder for people building PCRE on systems that don't run
1034        "configure". I have turned pcre.h into a distributed file, no longer built
1035        by "configure", with the version identification directly included. There is
1036        no longer a pcre.h.in file.
1037    
1038        However, this change necessitated a change to the pcre-config script as
1039        well. It is built from pcre-config.in, and one of the substitutions was the
1040        release number. I have updated configure.ac so that ./configure now finds
1041        the release number by grepping pcre.h.
1042    
1043    26. Added the ability to run the tests under valgrind.
1044    
1045    
1046    Version 6.4 05-Sep-05
1047    ---------------------
1048    
1049     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1050        "--" to be printed when multiple files were scanned, even when none of the
1051        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1052        consider it to be a bug, and have restored the previous behaviour.
1053    
1054     2. A couple of code tidies to get rid of compiler warnings.
1055    
1056     3. The pcretest program used to cheat by referring to symbols in the library
1057        whose names begin with _pcre_. These are internal symbols that are not
1058        really supposed to be visible externally, and in some environments it is
1059        possible to suppress them. The cheating is now confined to including
1060        certain files from the library's source, which is a bit cleaner.
1061    
1062     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1063        file's purpose clearer.
1064    
1065     5. Reorganized pcre_ucp_findchar().
1066    
1067    
1068    Version 6.3 15-Aug-05
1069    ---------------------
1070    
1071     1. The file libpcre.pc.in did not have general read permission in the tarball.
1072    
1073     2. There were some problems when building without C++ support:
1074    
1075        (a) If C++ support was not built, "make install" and "make test" still
1076            tried to test it.
1077    
1078        (b) There were problems when the value of CXX was explicitly set. Some
1079            changes have been made to try to fix these, and ...
1080    
1081        (c) --disable-cpp can now be used to explicitly disable C++ support.
1082    
1083        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1084            backslash in a target when C++ was disabled. This confuses some
1085            versions of "make", apparently. Using an intermediate variable solves
1086            this. (Same for CPP_LOBJ.)
1087    
1088     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1089        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1090        necessary on certain architectures.
1091    
1092     4. Added a setting of -export-symbols-regex to the link command to remove
1093        those symbols that are exported in the C sense, but actually are local
1094        within the library, and not documented. Their names all begin with
1095        "_pcre_". This is not a perfect job, because (a) we have to except some
1096        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1097        available (and never for static libraries). I have made a note to try to
1098        find a way round (a) in the future.
1099    
1100    
1101    Version 6.2 01-Aug-05
1102    ---------------------
1103    
1104     1. There was no test for integer overflow of quantifier values. A construction
1105        such as {1111111111111111} would give undefined results. What is worse, if
1106        a minimum quantifier for a parenthesized subpattern overflowed and became
1107        negative, the calculation of the memory size went wrong. This could have
1108        led to memory overwriting.
1109    
1110     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1111    
1112     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1113        operating environments where this matters.
1114    
1115     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1116        PCRE options from within the C++ wrapper.
1117    
1118     5. Named capturing subpatterns were not being correctly counted when a pattern
1119        was compiled. This caused two problems: (a) If there were more than 100
1120        such subpatterns, the calculation of the memory needed for the whole
1121        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1122        back references of the form \12, where the number was greater than 9, were
1123        not recognized as back references, even though there were sufficient
1124        previous subpatterns.
1125    
1126     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1127        versions of gcc, e.g. 2.95.4.
1128    
1129    
1130    Version 6.1 21-Jun-05
1131    ---------------------
1132    
1133     1. There was one reference to the variable "posix" in pcretest.c that was not
1134        surrounded by "#if !defined NOPOSIX".
1135    
1136     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1137        the cross-check on the old pcre_info() function, for the benefit of the
1138        cut-down version of PCRE that is currently imported into Exim.
1139    
1140     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1141        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1142        patterns that start (?i) but I don't think that matters. The use of (?i) is
1143        just an example; this all applies to the other options as well.
1144    
1145     4. Since libtool seems to echo the compile commands it is issuing, the output
1146        from "make" can be reduced a bit by putting "@" in front of each libtool
1147        compile command.
1148    
1149     5. Patch from the folks at Google for configure.in to be a bit more thorough
1150        in checking for a suitable C++ installation before trying to compile the
1151        C++ stuff. This should fix a reported problem when a compiler was present,
1152        but no suitable headers.
1153    
1154     6. The man pages all had just "PCRE" as their title. I have changed them to
1155        be the relevant file name. I have also arranged that these names are
1156        retained in the file doc/pcre.txt, which is a concatenation in text format
1157        of all the man pages except the little individual ones for each function.
1158    
1159     7. The NON-UNIX-USE file had not been updated for the different set of source
1160        files that come with release 6. I also added a few comments about the C++
1161        wrapper.
1162    
1163    
1164    Version 6.0 07-Jun-05
1165    ---------------------
1166    
1167     1. Some minor internal re-organization to help with my DFA experiments.
1168    
1169     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1170        didn't matter for the library itself when fully configured, but did matter
1171        when compiling without UCP support, or within Exim, where the ucp files are
1172        not imported.
1173    
1174     3. Refactoring of the library code to split up the various functions into
1175        different source modules. The addition of the new DFA matching code (see
1176        below) to a single monolithic source would have made it really too
1177        unwieldy, quite apart from causing all the code to be include in a
1178        statically linked application, when only some functions are used. This is
1179        relevant even without the DFA addition now that patterns can be compiled in
1180        one application and matched in another.
1181    
1182        The downside of splitting up is that there have to be some external
1183        functions and data tables that are used internally in different modules of
1184        the library but which are not part of the API. These have all had their
1185        names changed to start with "_pcre_" so that they are unlikely to clash
1186        with other external names.
1187    
1188     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1189        a different (DFA) algorithm. Although it is slower than the original
1190        function, it does have some advantages for certain types of matching
1191        problem.
1192    
1193     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1194        including restarting after a partial match.
1195    
1196     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1197        defined when compiling for Windows was sent to me. I have put it into the
1198        code, though I have no means of testing or verifying it.
1199    
1200     7. Added the pcre_refcount() auxiliary function.
1201    
1202     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1203        match before or at the first newline in the subject string. In pcretest,
1204        the /f option on a pattern can be used to set this.
1205    
1206     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1207        would behave wrongly. This has been present in PCRE since release 4.0.
1208    
1209    10. A number of changes to the pcregrep command:
1210    
1211        (a) Refactored how -x works; insert ^(...)$ instead of setting
1212            PCRE_ANCHORED and checking the length, in preparation for adding
1213            something similar for -w.
1214    
1215        (b) Added the -w (match as a word) option.
1216    
1217        (c) Refactored the way lines are read and buffered so as to have more
1218            than one at a time available.
1219    
1220        (d) Implemented a pcregrep test script.
1221    
1222        (e) Added the -M (multiline match) option. This allows patterns to match
1223            over several lines of the subject. The buffering ensures that at least
1224            8K, or the rest of the document (whichever is the shorter) is available
1225            for matching (and similarly the previous 8K for lookbehind assertions).
1226    
1227        (f) Changed the --help output so that it now says
1228    
1229              -w, --word-regex(p)
1230    
1231            instead of two lines, one with "regex" and the other with "regexp"
1232            because that confused at least one person since the short forms are the
1233            same. (This required a bit of code, as the output is generated
1234            automatically from a table. It wasn't just a text change.)
1235    
1236        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1237            option but starts with a hyphen. Could be a pattern or a path name
1238            starting with a hyphen, for instance.
1239    
1240        (h) "-" can be given as a file name to represent stdin.
1241    
1242        (i) When file names are being printed, "(standard input)" is used for
1243            the standard input, for compatibility with GNU grep. Previously
1244            "<stdin>" was used.
1245    
1246        (j) The option --label=xxx can be used to supply a name to be used for
1247            stdin when file names are being printed. There is no short form.
1248    
1249        (k) Re-factored the options decoding logic because we are going to add
1250            two more options that take data. Such options can now be given in four
1251            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1252    
1253        (l) Added the -A, -B, and -C options for requesting that lines of context
1254            around matches be printed.
1255    
1256        (m) Added the -L option to print the names of files that do not contain
1257            any matching lines, that is, the complement of -l.
1258    
1259        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1260            continue to scan other files.
1261    
1262        (o) The -s option was incorrectly implemented. For compatibility with other
1263            greps, it now suppresses the error message for a non-existent or non-
1264            accessible file (but not the return code). There is a new option called
1265            -q that suppresses the output of matching lines, which was what -s was
1266            previously doing.
1267    
1268        (p) Added --include and --exclude options to specify files for inclusion
1269            and exclusion when recursing.
1270    
1271    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1272        Hopefully, it now does.
1273    
1274    12. Missing cast in pcre_study().
1275    
1276    13. Added an "uninstall" target to the makefile.
1277    
1278    14. Replaced "extern" in the function prototypes in Makefile.in with
1279        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1280        world, but is set differently for Windows.
1281    
1282    15. Added a second compiling function called pcre_compile2(). The only
1283        difference is that it has an extra argument, which is a pointer to an
1284        integer error code. When there is a compile-time failure, this is set
1285        non-zero, in addition to the error test pointer being set to point to an
1286        error message. The new argument may be NULL if no error number is required
1287        (but then you may as well call pcre_compile(), which is now just a
1288        wrapper). This facility is provided because some applications need a
1289        numeric error indication, but it has also enabled me to tidy up the way
1290        compile-time errors are handled in the POSIX wrapper.
1291    
1292    16. Added VPATH=.libs to the makefile; this should help when building with one
1293        prefix path and installing with another. (Or so I'm told by someone who
1294        knows more about this stuff than I do.)
1295    
1296    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1297        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1298        match everything, including newlines. This is not POSIX-compatible, but
1299        somebody wanted the feature. From pcretest it can be activated by using
1300        both the P and the s flags.
1301    
1302    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1303    
1304    19. libpcre.pc was being incorrectly installed as executable.
1305    
1306    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1307        it now also looks for '\r' so that it will work unmodified on Windows.
1308    
1309    21. Added Google's contributed C++ wrapper to the distribution.
1310    
1311    22. Added some untidy missing memory free() calls in pcretest, to keep
1312        Electric Fence happy when testing.
1313    
1314    
1315    
1316    Version 5.0 13-Sep-04
1317    ---------------------
1318    
1319     1. Internal change: literal characters are no longer packed up into items
1320        containing multiple characters in a single byte-string. Each character
1321        is now matched using a separate opcode. However, there may be more than one
1322        byte in the character in UTF-8 mode.
1323    
1324     2. The pcre_callout_block structure has two new fields: pattern_position and
1325        next_item_length. These contain the offset in the pattern to the next match
1326        item, and its length, respectively.
1327    
1328     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1329        insertion of callouts before each pattern item. Added the /C option to
1330        pcretest to make use of this.
1331    
1332     4. On the advice of a Windows user, the lines
1333    
1334          #if defined(_WIN32) || defined(WIN32)
1335          _setmode( _fileno( stdout ), 0x8000 );
1336          #endif  /* defined(_WIN32) || defined(WIN32) */
1337    
1338        have been added to the source of pcretest. This apparently does useful
1339        magic in relation to line terminators.
1340    
1341     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1342        for the benefit of those environments where the "b" makes a difference.
1343    
1344     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1345        to know about it. I have put a hack into configure.in that adds in code
1346        to set GCC=yes if CC=icc. This seems to end up at a point in the
1347        generated configure script that is early enough to affect the setting of
1348        compiler options, which is what is needed, but I have no means of testing
1349        whether it really works. (The user who reported this had patched the
1350        generated configure script, which of course I cannot do.)
1351    
1352        LATER: After change 22 below (new libtool files), the configure script
1353        seems to know about icc (and also ecc). Therefore, I have commented out
1354        this hack in configure.in.
1355    
1356     7. Added support for pkg-config (2 patches were sent in).
1357    
1358     8. Negated POSIX character classes that used a combination of internal tables
1359        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1360        [[:^ascii]]. Typically, they would match almost any characters. The other
1361        POSIX classes were not broken in this way.
1362    
1363     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1364        to find the match, as PCRE was deluded into thinking that the match had to
1365        start at the start point or following a newline. The same bug applied to
1366        patterns with negative forward assertions or any backward assertions
1367        preceding ".*" at the start, unless the pattern required a fixed first
1368        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1369    
1370    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1371        starting at the last subject character, bytes beyond the end of the subject
1372        string were read.
1373    
1374    11. Renamed the variable "class" as "classbits" to make life easier for C++
1375        users. (Previously there was a macro definition, but it apparently wasn't
1376        enough.)
1377    
1378    12. Added the new field "tables" to the extra data so that tables can be passed
1379        in at exec time, or the internal tables can be re-selected. This allows
1380        a compiled regex to be saved and re-used at a later time by a different
1381        program that might have everything at different addresses.
1382    
1383    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1384        -R library as well as a -L library.
1385    
1386    14. The debugging options of pcretest (-d on the command line or D on a
1387        pattern) showed incorrect output for anything following an extended class
1388        that contained multibyte characters and which was followed by a quantifier.
1389    
1390    15. Added optional support for general category Unicode character properties
1391        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1392        support. It adds about 90K to the size of the library. The meanings of the
1393        inbuilt class escapes such as \d and \s have NOT been changed.
1394    
1395    16. Updated pcredemo.c to include calls to free() to release the memory for the
1396        compiled pattern.
1397    
1398    17. The generated file chartables.c was being created in the source directory
1399        instead of in the building directory. This caused the build to fail if the
1400        source directory was different from the building directory, and was
1401        read-only.
1402    
1403    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1404        file. No doubt somebody will tell me if they don't make sense... Also added
1405        Dan Mooney's comments about building on OpenVMS.
1406    
1407    19. Added support for partial matching via the PCRE_PARTIAL option for
1408        pcre_exec() and the \P data escape in pcretest.
1409    
1410    20. Extended pcretest with 3 new pattern features:
1411    
1412        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1413              write the compiled pattern to the file whose name is "rest-of-line".
1414              This is a straight binary dump of the data, with the saved pointer to
1415              the character tables forced to be NULL. The study data, if any, is
1416              written too. After writing, pcretest reads a new pattern.
1417    
1418        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1419              compiled pattern from the given file. There must not be any
1420              occurrences of "<" in the file name (pretty unlikely); if there are,
1421              pcretest will instead treat the initial "<" as a pattern delimiter.
1422              After reading in the pattern, pcretest goes on to read data lines as
1423              usual.
1424    
1425        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1426              and 16-bit fields in a compiled pattern, to simulate a pattern that
1427              was compiled on a host of opposite endianness.
1428    
1429    21. The pcre-exec() function can now cope with patterns that were compiled on
1430        hosts of opposite endianness, with this restriction:
1431    
1432          As for any compiled expression that is saved and used later, the tables
1433          pointer field cannot be preserved; the extra_data field in the arguments
1434          to pcre_exec() should be used to pass in a tables address if a value
1435          other than the default internal tables were used at compile time.
1436    
1437    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1438        now diagnosed as an error. Previously, most of the time, a negative number
1439        would have been treated as zero, but if in addition "ovector" was passed as
1440        NULL, a crash could occur.
1441    
1442    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1443        new versions from the libtool 1.5 distribution (the last one is a copy of
1444        a file called libtool.m4). This seems to have fixed the need to patch
1445        "configure" to support Darwin 1.3 (which I used to do). However, I still
1446        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1447        workstation).
1448    
1449    24. Changed the PCRE licence to be the more standard "BSD" licence.
1450    
1451    
1452    Version 4.5 01-Dec-03
1453    ---------------------
1454    
1455     1. There has been some re-arrangement of the code for the match() function so
1456        that it can be compiled in a version that does not call itself recursively.
1457        Instead, it keeps those local variables that need separate instances for
1458        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1459        needs to "recurse". Keeping track of where control must go is done by means
1460        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1461        hide most of the details from the main code, and operates only if
1462        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1463        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1464        operating.
1465    
1466        To make it easier for callers to provide specially tailored get/free
1467        functions for this usage, two new functions, pcre_stack_malloc, and
1468        pcre_stack_free, are used. They are always called in strict stacking order,
1469        and the size of block requested is always the same.
1470    
1471        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1472        PCRE has been compiled to use the stack or the heap for recursion. The
1473        -C option of pcretest uses this to show which version is compiled.
1474    
1475        A new data escape \S, is added to pcretest; it causes the amounts of store
1476        obtained and freed by both kinds of malloc/free at match time to be added
1477        to the output.
1478    
1479     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1480        what's available on my current Linux desktop machine.
1481    
1482     3. When matching a UTF-8 string, the test for a valid string at the start has
1483        been extended. If start_offset is not zero, PCRE now checks that it points
1484        to a byte that is the start of a UTF-8 character. If not, it returns
1485        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1486        this is necessary because there may be backward assertions in the pattern.
1487        When matching the same subject several times, it may save resources to use
1488        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1489    
1490     4. The code for checking the validity of UTF-8 strings has been tightened so
1491        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1492        containing "overlong sequences".
1493    
1494     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1495        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1496        should have been "&", but it just so happened that all the cases this let
1497        through by mistake were picked up later in the function.
1498    
1499     6. I had used a variable called "isblank" - this is a C99 function, causing
1500        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1501    
1502     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1503        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1504        so the version is shown; (c) stop "make test" echoing "./RunTest".
1505    
1506     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1507    
1508     9. The prototype for memmove() for systems that don't have it was using
1509        size_t, but the inclusion of the header that defines size_t was later. I've
1510        moved the #includes for the C headers earlier to avoid this.
1511    
1512    10. Added some adjustments to the code to make it easier to compiler on certain
1513        special systems:
1514    
1515          (a) Some "const" qualifiers were missing.
1516          (b) Added the macro EXPORT before all exported functions; by default this
1517              is defined to be empty.
1518          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1519              that it reads its output file name as an argument instead of writing
1520              to the standard output and assuming this can be redirected.
1521    
1522    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1523        class containing characters with values greater than 255, PCRE compilation
1524        went into a loop.
1525    
1526    12. A recursive reference to a subpattern that was within another subpattern
1527        that had a minimum quantifier of zero caused PCRE to crash. For example,
1528        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1529        recursion. If the recursively-called subpattern itself had a zero repeat,
1530        that was OK.
1531    
1532    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1533        buffer into which it was copied (for escape processing) was still set at
1534        1024, so long lines caused crashes.
1535    
1536    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1537        "internal error: code overflow...". This applied to any character class
1538        that was followed by a possessive quantifier.
1539    
1540    15. Modified the Makefile to add libpcre.la as a prerequisite for
1541        libpcreposix.la because I was told this is needed for a parallel build to
1542        work.
1543    
1544    16. If a pattern that contained .* following optional items at the start was
1545        studied, the wrong optimizing data was generated, leading to matching
1546        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1547        matching string must start with a or b or c. The correct conclusion for
1548        this pattern is that a match can start with any character.
1549    
1550    
1551    Version 4.4 13-Aug-03
1552    ---------------------
1553    
1554     1. In UTF-8 mode, a character class containing characters with values between
1555        127 and 255 was not handled correctly if the compiled pattern was studied.
1556        In fixing this, I have also improved the studying algorithm for such
1557        classes (slightly).
1558    
1559     2. Three internal functions had redundant arguments passed to them. Removal
1560        might give a very teeny performance improvement.
1561    
1562     3. Documentation bug: the value of the capture_top field in a callout is *one
1563        more than* the number of the hightest numbered captured substring.
1564    
1565     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1566        in incorrectly linking with a previously installed version. They now link
1567        explicitly with libpcre.la.
1568    
1569     5. configure.in no longer needs to recognize Cygwin specially.
1570    
1571     6. A problem in pcre.in for Windows platforms is fixed.
1572    
1573     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1574        pcretest, it used to include the size of the study block as part of its
1575        output. Unfortunately, the structure contains a field that has a different
1576        size on different hardware architectures. This meant that the tests that
1577        showed this size failed. As the block is currently always of a fixed size,
1578        this information isn't actually particularly useful in pcretest output, so
1579        I have just removed it.
1580    
1581     8. Three pre-processor statements accidentally did not start in column 1.
1582        Sadly, there are *still* compilers around that complain, even though
1583        standard C has not required this for well over a decade. Sigh.
1584    
1585     9. In pcretest, the code for checking callouts passed small integers in the
1586        callout_data field, which is a void * field. However, some picky compilers
1587        complained about the casts involved for this on 64-bit systems. Now
1588        pcretest passes the address of the small integer instead, which should get
1589        rid of the warnings.
1590    
1591    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1592        both compile and run time, and gives an error if an invalid UTF-8 sequence
1593        is found. There is a option for disabling this check in cases where the
1594        string is known to be correct and/or the maximum performance is wanted.
1595    
1596    11. In response to a bug report, I changed one line in Makefile.in from
1597    
1598            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1599        to
1600            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1601    
1602        to look similar to other lines, but I have no way of telling whether this
1603        is the right thing to do, as I do not use Windows. No doubt I'll get told
1604        if it's wrong...
1605    
1606    
1607    Version 4.3 21-May-03
1608    ---------------------
1609    
1610    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1611       Makefile.
1612    
1613    2. Some refactoring to improve the quality of the code:
1614    
1615       (i)   The utf8_table... variables are now declared "const".
1616    
1617       (ii)  The code for \cx, which used the "case flipping" table to upper case
1618             lower case letters, now just substracts 32. This is ASCII-specific,
1619             but the whole concept of \cx is ASCII-specific, so it seems
1620             reasonable.
1621    
1622       (iii) PCRE was using its character types table to recognize decimal and
1623             hexadecimal digits in the pattern. This is silly, because it handles
1624             only 0-9, a-f, and A-F, but the character types table is locale-
1625             specific, which means strange things might happen. A private
1626             table is now used for this - though it costs 256 bytes, a table is
1627             much faster than multiple explicit tests. Of course, the standard
1628             character types table is still used for matching digits in subject
1629             strings against \d.
1630    
1631       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1632             ending in _t are). So I've renamed it as ESC_tee.
1633    
1634    3. The first argument for regexec() in the POSIX wrapper should have been
1635       defined as "const".
1636    
1637    4. Changed pcretest to use malloc() for its buffers so that they can be
1638       Electric Fenced for debugging.
1639    
1640    5. There were several places in the code where, in UTF-8 mode, PCRE would try
1641       to read one or more bytes before the start of the subject string. Often this
1642       had no effect on PCRE's behaviour, but in some circumstances it could
1643       provoke a segmentation fault.
1644    
1645    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1646       to try to read one or more bytes before the start of the subject string.
1647    
1648    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1649       UTF-8 support could misbehave in various ways if the subject string
1650       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1651       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1652       back over UTF-8 characters.)
1653    
1654    
1655    Version 4.2 14-Apr-03
1656    ---------------------
1657    
1658    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1659    
1660    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1661         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1662         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1663         [WIN_PREFIX]: new variable, "cyg" for Cygwin
1664         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1665           and BUILD_EXEEXT
1666         Note: automatic setting of the BUILD variables is not yet working
1667         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1668           compile-time but not at link-time
1669         [LINK]: use for linking executables only
1670         make different versions for Windows and non-Windows
1671         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1672           libraries
1673         [LINK_FOR_BUILD]: new variable
1674         [OBJEXT]: use throughout
1675         [EXEEXT]: use throughout
1676         <winshared>: new target
1677         <wininstall>: new target
1678         <dftables.o>: use native compiler
1679         <dftables>: use native linker
1680         <install>: handle Windows platform correctly
1681         <clean>: ditto
1682         <check>: ditto
1683         copy DLL to top builddir before testing
1684    
1685       As part of these changes, -no-undefined was removed again. This was reported
1686       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1687       in any case.
1688    
1689    3. Some tidies to get rid of compiler warnings:
1690    
1691       . In the match_data structure, match_limit was an unsigned long int, whereas
1692         match_call_count was an int. I've made them both unsigned long ints.
1693    
1694       . In pcretest the fact that a const uschar * doesn't automatically cast to
1695         a void * provoked a warning.
1696    
1697       . Turning on some more compiler warnings threw up some "shadow" variables
1698         and a few more missing casts.
1699    
1700    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1701       option, a class that contained a single character with a value between 128
1702       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1703    
1704    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1705       option, a class that contained several characters, but with at least one
1706       whose value was between 128 and 255 caused PCRE to crash.
1707    
1708    
1709    Version 4.1 12-Mar-03
1710    ---------------------
1711    
1712    1. Compiling with gcc -pedantic found a couple of places where casts were
1713    needed, and a string in dftables.c that was longer than standard compilers are
1714    required to support.
1715    
1716    2. Compiling with Sun's compiler found a few more places where the code could
1717    be tidied up in order to avoid warnings.
1718    
1719    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1720    first of these names is deprecated in the latest Autoconf in favour of the name
1721    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1722    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1723    analogy I have changed it to CFLAGS_FOR_BUILD.
1724    
1725    4. Added -no-undefined to the linking command in the Makefile, because this is
1726    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1727    linking step for the pcreposix library.
1728    
1729    5. PCRE was failing to diagnose the case of two named groups with the same
1730    name.
1731    
1732    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1733    literal character that is needed in the subject for a match, and scans along to
1734    ensure that it is present before embarking on the full matching process. This
1735    saves time in cases of nested unlimited repeats that are never going to match.
1736    Problem: the scan can take a lot of time if the subject is very long (e.g.
1737    megabytes), thus penalizing straightforward matches. It is now done only if the
1738    amount of subject to be scanned is less than 1000 bytes.
1739    
1740    7. A lesser problem with the same optimization is that it was recording the
1741    first character of an anchored pattern as "needed", thus provoking a search
1742    right along the subject, even when the first match of the pattern was going to
1743    fail. The "needed" character is now not set for anchored patterns, unless it
1744    follows something in the pattern that is of non-fixed length. Thus, it still
1745    fulfils its original purpose of finding quick non-matches in cases of nested
1746    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1747    
1748    
1749    Version 4.0 17-Feb-03
1750    ---------------------
1751    
1752    1. If a comment in an extended regex that started immediately after a meta-item
1753    extended to the end of string, PCRE compiled incorrect data. This could lead to
1754    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1755    
1756    2. Moved to autoconf 2.53 and libtool 1.4.2.
1757    
1758    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1759    the special perltest8 script is no longer needed - all the tests can be run
1760    from a single perltest script.
1761    
1762    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1763    by \s. It has now been removed in PCRE. This means it isn't recognized as
1764    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1765    class [:space:] *does* include VT, thereby creating a mess.
1766    
1767    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1768    space and tab.
1769    
1770    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1771    its new features into the main test script, reducing the number of scripts.
1772    
1773    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1774    were backward compatible, and made the (?i) apply to the whole pattern, as if
1775    /i were given. Now it behaves more logically, and applies the option setting
1776    only to what follows. PCRE has been changed to follow suit. However, if it
1777    finds options settings right at the start of the pattern, it extracts them into
1778    the global options, as before. Thus, they show up in the info data.
1779    
1780    8. Added support for the \Q...\E escape sequence. Characters in between are
1781    treated as literals. This is slightly different from Perl in that $ and @ are
1782    also handled as literals inside the quotes. In Perl, they will cause variable
1783    interpolation. Note the following examples:
1784    
1785        Pattern            PCRE matches      Perl matches
1786    
1787        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
1788        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
1789        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
1790    
1791    For compatibility with Perl, \Q...\E sequences are recognized inside character
1792    classes as well as outside them.
1793    
1794    9. Re-organized 3 code statements in pcretest to avoid "overflow in
1795    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1796    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1797    signed/unsigned warnings.
1798    
1799    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1800    option for pcretest, so I've replaced it by a simple function that does just
1801    that job.
1802    
1803    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1804    "pcregrep -".
1805    
1806    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1807    Java package. This provides some syntactic sugar for simple cases of what my
1808    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1809    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1810    item, you can use this simplified notation. Note that only makes sense with
1811    greedy quantifiers. Consequently, the use of the possessive quantifier forces
1812    greediness, whatever the setting of the PCRE_UNGREEDY option.
1813    
1814    13. A change of greediness default within a pattern was not taking effect at
1815    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1816    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1817    was abstracted outside.
1818    
1819    14. PCRE now supports the \G assertion. It is true when the current matching
1820    position is at the start point of the match. This differs from \A when the
1821    starting offset is non-zero. Used with the /g option of pcretest (or similar
1822    code), it works in the same way as it does for Perl's /g option. If all
1823    alternatives of a regex begin with \G, the expression is anchored to the start
1824    match position, and the "anchored" flag is set in the compiled expression.
1825    
1826    15. Some bugs concerning the handling of certain option changes within patterns
1827    have been fixed. These applied to options other than (?ims). For example,
1828    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1829    been the other way round. Some of this was related to change 7 above.
1830    
1831    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1832    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1833    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1834    POSIX classes only within a class (e.g. /[[:alpha:]]/).
1835    
1836    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1837    mode. Unlike ".", it always matches newline, whatever the setting of
1838    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1839    assertions. Perl allows it, but it doesn't (in general) work because it can't
1840    calculate the length of the lookbehind. At least, that's the case for Perl
1841    5.8.0 - I've been told they are going to document that it doesn't work in
1842    future.
1843    
1844    18. Added an error diagnosis for escapes that PCRE does not support: these are
1845    \L, \l, \N, \P, \p, \U, \u, and \X.
1846    
1847    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1848    reading past the end of the pattern in cases such as /[abcd/.
1849    
1850    20. PCRE was getting more memory than necessary for patterns with classes that
1851    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1852    
1853    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1854    compiling PCRE for use with Virtual Pascal.
1855    
1856    22. Small fix to the Makefile to make it work properly if the build is done
1857    outside the source tree.
1858    
1859    23. Added a new extension: a condition to go with recursion. If a conditional
1860    subpattern starts with (?(R) the "true" branch is used if recursion has
1861    happened, whereas the "false" branch is used only at the top level.
1862    
1863    24. When there was a very long string of literal characters (over 255 bytes
1864    without UTF support, over 250 bytes with UTF support), the computation of how
1865    much memory was required could be incorrect, leading to segfaults or other
1866    strange effects.
1867    
1868    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1869    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1870    there was a subsequent back reference to those brackets. This meant that, for
1871    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1872    possible to check for precisely this case. All we can do is abandon the
1873    optimization if .* occurs inside capturing brackets when there are any back
1874    references whatsoever. (See below for a better fix that came later.)
1875    
1876    26. The handling of the optimization for finding the first character of a
1877    non-anchored pattern, and for finding a character that is required later in the
1878    match were failing in some cases. This didn't break the matching; it just
1879    failed to optimize when it could. The way this is done has been re-implemented.
1880    
1881    27. Fixed typo in error message for invalid (?R item (it said "(?p").
1882    
1883    28. Added a new feature that provides some of the functionality that Perl
1884    provides with (?{...}). The facility is termed a "callout". The way it is done
1885    in PCRE is for the caller to provide an optional function, by setting
1886    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1887    global variable. By default it is unset, which disables all calling out. To get
1888    the function called, the regex must include (?C) at appropriate points. This
1889    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1890    This provides a means of identifying different callout points. When PCRE
1891    reaches such a point in the regex, if pcre_callout has been set, the external
1892    function is called. It is provided with data in a structure called
1893    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1894    matching continues; if it returns a non-zero value, the match at the current
1895    point fails. However, backtracking will occur if possible. [This was changed
1896    later and other features added - see item 49 below.]
1897    
1898    29. pcretest is upgraded to test the callout functionality. It provides a
1899    callout function that displays information. By default, it shows the start of
1900    the match and the current position in the text. There are some new data escapes
1901    to vary what happens:
1902    
1903        \C+         in addition, show current contents of captured substrings
1904        \C-         do not supply a callout function
1905        \C!n        return 1 when callout number n is reached
1906        \C!n!m      return 1 when callout number n is reached for the mth time
1907    
1908    30. If pcregrep was called with the -l option and just a single file name, it
1909    output "<stdin>" if a match was found, instead of the file name.
1910    
1911    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1912    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1913    pcre_exec(). This saves a malloc/free per call. The default value of
1914    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1915    when configuring.
1916    
1917    32. The default maximum size of a compiled pattern is 64K. There have been a
1918    few cases of people hitting this limit. The code now uses macros to handle the
1919    storing of links as offsets within the compiled pattern. It defaults to 2-byte
1920    links, but this can be changed to 3 or 4 bytes by --with-link-size when
1921    configuring. Tests 2 and 5 work only with 2-byte links because they output
1922    debugging information about compiled patterns.
1923    
1924    33. Internal code re-arrangements:
1925    
1926    (a) Moved the debugging function for printing out a compiled regex into
1927        its own source file (printint.c) and used #include to pull it into
1928        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1929        separate copies.
1930    
1931    (b) Defined the list of op-code names for debugging as a macro in
1932        internal.h so that it is next to the definition of the opcodes.
1933    
1934    (c) Defined a table of op-code lengths for simpler skipping along compiled
1935        code. This is again a macro in internal.h so that it is next to the
1936        definition of the opcodes.
1937    
1938    34. Added support for recursive calls to individual subpatterns, along the
1939    lines of Robin Houston's patch (but implemented somewhat differently).
1940    
1941    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1942    allow it to read and process whole directories in Win32. This code was
1943    contributed by Lionel Fourquaux; it has not been tested by me.
1944    
1945    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1946    used to name a group. Names consist of alphanumerics and underscores, and must
1947    be unique. Back references use the syntax (?P=name) and recursive calls use
1948    (?P>name) which is a PCRE extension to the Python extension. Groups still have
1949    numbers. The function pcre_fullinfo() can be used after compilation to extract
1950    a name/number map. There are three relevant calls:
1951    
1952      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
1953      PCRE_INFO_NAMECOUNT            yields the number of entries
1954      PCRE_INFO_NAMETABLE            yields a pointer to the map.
1955    
1956    The map is a vector of fixed-size entries. The size of each entry depends on
1957    the length of the longest name used. The first two bytes of each entry are the
1958    group number, most significant byte first. There follows the corresponding
1959    name, zero terminated. The names are in alphabetical order.
1960    
1961    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1962    case instead of 255. Making it the same both with and without UTF-8 support
1963    means that the same test output works with both.
1964    
1965    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1966    calling malloc() with a zero argument.
1967    
1968    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1969    optimization. I've improved things by keeping a bitmap of backreferences with
1970    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1971    fact referenced, the optimization can be applied. It is unlikely that a
1972    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1973    the match to follow \n) will appear inside brackets with a number greater than
1974    31, but if it does, any back reference > 31 suppresses the optimization.
1975    
1976    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1977    of disabling numbered capturing parentheses. Any opening parenthesis that is
1978    not followed by ? behaves as if it were followed by ?: but named parentheses
1979    can still be used for capturing (and they will acquire numbers in the usual
1980    way).
1981    
1982    41. Redesigned the return codes from the match() function into yes/no/error so
1983    that errors can be passed back from deep inside the nested calls. A malloc
1984    failure while inside a recursive subpattern call now causes the
1985    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1986    
1987    42. It is now possible to set a limit on the number of times the match()
1988    function is called in a call to pcre_exec(). This facility makes it possible to
1989    limit the amount of recursion and backtracking, though not in a directly
1990    obvious way, because the match() function is used in a number of different
1991    circumstances. The count starts from zero for each position in the subject
1992    string (for non-anchored patterns). The default limit is, for compatibility, a
1993    large number, namely 10 000 000. You can change this in two ways:
1994    
1995    (a) When configuring PCRE before making, you can use --with-match-limit=n
1996        to set a default value for the compiled library.
1997    
1998    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1999        a different value is set. See 45 below.
2000    
2001    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2002    
2003    43. Added a new function pcre_config(int, void *) to enable run-time extraction
2004    of things that can be changed at compile time. The first argument specifies
2005    what is wanted and the second points to where the information is to be placed.
2006    The current list of available information is:
2007    
2008      PCRE_CONFIG_UTF8
2009    
2010    The output is an integer that is set to one if UTF-8 support is available;
2011    otherwise it is set to zero.
2012    
2013      PCRE_CONFIG_NEWLINE
2014    
2015    The output is an integer that it set to the value of the code that is used for
2016    newline. It is either LF (10) or CR (13).
2017    
2018      PCRE_CONFIG_LINK_SIZE
2019    
2020    The output is an integer that contains the number of bytes used for internal
2021    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2022    
2023      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2024    
2025    The output is an integer that contains the threshold above which the POSIX
2026    interface uses malloc() for output vectors. See item 31 above.
2027    
2028      PCRE_CONFIG_MATCH_LIMIT
2029    
2030    The output is an unsigned integer that contains the default limit of the number
2031    of match() calls in a pcre_exec() execution. See 42 above.
2032    
2033    44. pcretest has been upgraded by the addition of the -C option. This causes it
2034    to extract all the available output from the new pcre_config() function, and to
2035    output it. The program then exits immediately.
2036    
2037    45. A need has arisen to pass over additional data with calls to pcre_exec() in
2038    order to support additional features. One way would have been to define
2039    pcre_exec2() (for example) with extra arguments, but this would not have been
2040    extensible, and would also have required all calls to the original function to
2041    be mapped to the new one. Instead, I have chosen to extend the mechanism that
2042    is used for passing in "extra" data from pcre_study().
2043    
2044    The pcre_extra structure is now exposed and defined in pcre.h. It currently
2045    contains the following fields:
2046    
2047      flags         a bitmap indicating which of the following fields are set
2048      study_data    opaque data from pcre_study()
2049      match_limit   a way of specifying a limit on match() calls for a specific
2050                      call to pcre_exec()
2051      callout_data  data for callouts (see 49 below)
2052    
2053    The flag bits are also defined in pcre.h, and are
2054    
2055      PCRE_EXTRA_STUDY_DATA
2056      PCRE_EXTRA_MATCH_LIMIT
2057      PCRE_EXTRA_CALLOUT_DATA
2058    
2059    The pcre_study() function now returns one of these new pcre_extra blocks, with
2060    the actual study data pointed to by the study_data field, and the
2061    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2062    before. That is, this change is entirely upwards-compatible and requires no
2063    change to existing code.
2064    
2065    If you want to pass in additional data to pcre_exec(), you can either place it
2066    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2067    block.
2068    
2069    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2070    data string contains the escape sequence \M, pcretest calls pcre_exec() several
2071    times with different match limits, until it finds the minimum value needed for
2072    pcre_exec() to complete. The value is then output. This can be instructive; for
2073    most simple matches the number is quite small, but for pathological cases it
2074    gets very large very quickly.
2075    
2076    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2077    returns the size of the data block pointed to by the study_data field in a
2078    pcre_extra block, that is, the value that was passed as the argument to
2079    pcre_malloc() when PCRE was getting memory in which to place the information
2080    created by pcre_study(). The fourth argument should point to a size_t variable.
2081    pcretest has been extended so that this information is shown after a successful
2082    pcre_study() call when information about the compiled regex is being displayed.
2083    
2084    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2085    because what follows is always an absolute path. (Later: it turns out that this
2086    is more than cosmetic for MinGW, because it doesn't like empty path
2087    components.)
2088    
2089    49. Some changes have been made to the callout feature (see 28 above):
2090    
2091    (i)  A callout function now has three choices for what it returns:
2092    
2093           0  =>  success, carry on matching
2094         > 0  =>  failure at this point, but backtrack if possible
2095         < 0  =>  serious error, return this value from pcre_exec()
2096    
2097         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2098         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2099         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2100         use by callout functions. It will never be used by PCRE itself.
2101    
2102    (ii) The pcre_extra structure (see 45 above) has a void * field called
2103         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2104         pcre_callout_block structure has a field of the same name. The contents of
2105         the field passed in the pcre_extra structure are passed to the callout
2106         function in the corresponding field in the callout block. This makes it
2107         easier to use the same callout-containing regex from multiple threads. For
2108         testing, the pcretest program has a new data escape
2109    
2110           \C*n        pass the number n (may be negative) as callout_data
2111    
2112         If the callout function in pcretest receives a non-zero value as
2113         callout_data, it returns that value.
2114    
2115    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2116    there were some redundant $(CFLAGS) in commands that are now specified as
2117    $(LINK), which already includes $(CFLAGS).
2118    
2119    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2120    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2121    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2122    one-byte characters throughout. Note that case-insensitive matching applies
2123    only to characters whose values are less than 256. PCRE doesn't support the
2124    notion of cases for higher-valued characters.
2125    
2126    (i)   A character class whose characters are all within 0-255 is handled as
2127          a bit map, and the map is inverted for negative classes. Previously, a
2128          character > 255 always failed to match such a class; however it should
2129          match if the class was a negative one (e.g. [^ab]). This has been fixed.
2130    
2131    (ii)  A negated character class with a single character < 255 is coded as
2132          "not this character" (OP_NOT). This wasn't working properly when the test
2133          character was multibyte, either singly or repeated.
2134    
2135    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2136          mode, for example: \x{100}{2,3}.
2137    
2138    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2139          singly or repeated) now correctly test multibyte characters. However,
2140          PCRE doesn't recognize any characters with values greater than 255 as
2141          digits, spaces, or word characters. Such characters always match \D, \S,
2142          and \W, and never match \d, \s, or \w.
2143    
2144    (v)   Classes may now contain characters and character ranges with values
2145          greater than 255. For example: [ab\x{100}-\x{400}].
2146    
2147    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
2148          PCRE in UTF-8 mode.
2149    
2150    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2151    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2152    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2153    value.)
2154    
2155    53. The single man page has become too large. I have therefore split it up into
2156    a number of separate man pages. These also give rise to individual HTML pages;
2157    these are now put in a separate directory, and there is an index.html page that
2158    lists them all. Some hyperlinking between the pages has been installed.
2159    
2160    54. Added convenience functions for handling named capturing parentheses.
2161    
2162    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2163    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2164    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2165    are faulted.
2166    
2167    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2168    calling configure. These values are used when compiling the dftables.c program
2169    which is run to generate the source of the default character tables. They
2170    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2171    you will need to set these values.
2172    
2173    57. Updated the building process for Windows DLL, as provided by Fred Cox.
2174    
2175    
2176    Version 3.9 02-Jan-02
2177    ---------------------
2178    
2179    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2180    
2181    2. If --disable-static was given, the building process failed when trying to
2182    build pcretest and pcregrep. (For some reason it was using libtool to compile
2183    them, which is not right, as they aren't part of the library.)
2184    
2185    
2186    Version 3.8 18-Dec-01
2187    ---------------------
2188    
2189    1. The experimental UTF-8 code was completely screwed up. It was packing the
2190    bytes in the wrong order. How dumb can you get?
2191    
2192    
2193    Version 3.7 29-Oct-01
2194    ---------------------
2195    
2196    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2197    This caused pcretest, when used on the test data, to segfault. Unfortunately,
2198    this didn't happen under Solaris 8, where I normally test things.
2199    
2200    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2201    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2202    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2203    this fix an hour or so after the initial 3.7 release.)
2204    
2205    
2206    Version 3.6 23-Oct-01
2207    ---------------------
2208    
2209    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2210    offsets passed as NULL with zero offset count.
2211    
2212    2. The config.guess and config.sub files had not been updated when I moved to
2213    the latest autoconf.
2214    
2215    
2216    Version 3.5 15-Aug-01
2217    ---------------------
2218    
2219    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2220    had been forgotten.
2221    
2222    2. By using declared but undefined structures, we can avoid using "void"
2223    definitions in pcre.h while keeping the internal definitions of the structures
2224    private.
2225    
2226    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2227    user point of view, this means that both static and shared libraries are built
2228    by default, but this can be individually controlled. More of the work of
2229    handling this static/shared cases is now inside libtool instead of PCRE's make
2230    file.
2231    
2232    4. The pcretest utility is now installed along with pcregrep because it is
2233    useful for users (to test regexs) and by doing this, it automatically gets
2234    relinked by libtool. The documentation has been turned into a man page, so
2235    there are now .1, .txt, and .html versions in /doc.
2236    
2237    5. Upgrades to pcregrep:
2238       (i)   Added long-form option names like gnu grep.
2239       (ii)  Added --help to list all options with an explanatory phrase.
2240       (iii) Added -r, --recursive to recurse into sub-directories.
2241       (iv)  Added -f, --file to read patterns from a file.
2242    
2243    6. pcre_exec() was referring to its "code" argument before testing that
2244    argument for NULL (and giving an error if it was NULL).
2245    
2246    7. Upgraded Makefile.in to allow for compiling in a different directory from
2247    the source directory.
2248    
2249    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2250    options bits, the pointer it was passed was to an int instead of to an unsigned
2251    long int. This mattered only on 64-bit systems.
2252    
2253    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2254    generated) instead of pcre.in, which it its source. Also made the same change
2255    in several of the .c files.
2256    
2257    10. A new release of gcc defines printf() as a macro, which broke pcretest
2258    because it had an ifdef in the middle of a string argument for printf(). Fixed
2259    by using separate calls to printf().
2260    
2261    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2262    script, to force use of CR or LF instead of \n in the source. On non-Unix
2263    systems, the value can be set in config.h.
2264    
2265    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2266    absolute limit. Changed the text of the error message to make this clear, and
2267    likewise updated the man page.
2268    
2269    13. The limit of 99 on the number of capturing subpatterns has been removed.
2270    The new limit is 65535, which I hope will not be a "real" limit.
2271    
2272    
2273    Version 3.4 22-Aug-00
2274    ---------------------
2275    
2276    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2277    
2278    2. Diagnose condition (?(0) as an error instead of crashing on matching.
2279    
2280    
2281    Version 3.3 01-Aug-00
2282    ---------------------
2283    
2284    1. If an octal character was given, but the value was greater than \377, it
2285    was not getting masked to the least significant bits, as documented. This could
2286    lead to crashes in some systems.
2287    
2288    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2289    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2290    
2291    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2292    These just pass their arguments on to (pcre_free)(), but they are provided
2293    because some uses of PCRE bind it to non-C systems that can call its functions,
2294    but cannot call free() or pcre_free() directly.
2295    
2296    4. Add "make test" as a synonym for "make check". Corrected some comments in
2297    the Makefile.
2298    
2299    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2300    Makefile.
2301    
2302    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2303    command called pgrep for grepping around the active processes.
2304    
2305    7. Added the beginnings of support for UTF-8 character strings.
2306    
2307    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2308    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2309    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2310    out for the ar command.)
2311    
2312    
2313    Version 3.2 12-May-00
2314    ---------------------
2315    
2316    This is purely a bug fixing release.
2317    
2318    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2319    of ZA. This was just one example of several cases that could provoke this bug,
2320    which was introduced by change 9 of version 2.00. The code for breaking
2321    infinite loops after an iteration that matches an empty string was't working
2322    correctly.
2323    
2324    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2325    when matched against abbab (for example). After matching an empty string, it
2326    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2327    caused it to match further down the string than it should.
2328    
2329    3. The code contained an inclusion of sys/types.h. It isn't clear why this
2330    was there because it doesn't seem to be needed, and it causes trouble on some
2331    systems, as it is not a Standard C header. It has been removed.
2332    
2333    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2334    were reported on the Macintosh. The changes were from
2335    
2336      while ((c = *(++ptr)) != 0 && c != '\n');
2337    to
2338      while ((c = *(++ptr)) != 0 && c != '\n') ;
2339    
2340    Totally extraordinary, but if that's what it takes...
2341    
2342    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2343    available. Added HAVE_BCOPY and an autoconf test for it; if neither
2344    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2345    assumes the way PCRE uses memmove() (always moving upwards).
2346    
2347    6. PCRE is being used in one environment where strchr() is not available. There
2348    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2349    faster code anyway.
2350    
2351    
2352    Version 3.1 09-Feb-00
2353    ---------------------
2354    
2355    The only change in this release is the fixing of some bugs in Makefile.in for
2356    the "install" target:
2357    
2358    (1) It was failing to install pcreposix.h.
2359    
2360    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2361    
2362    
2363    Version 3.0 01-Feb-00
2364    ---------------------
2365    
2366    1. Add support for the /+ modifier to perltest (to output $` like it does in
2367    pcretest).
2368    
2369    2. Add support for the /g modifier to perltest.
2370    
2371    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2372    matches null strings.
2373    
2374    4. Fix perltest so that it doesn't do unwanted things when fed an empty
2375    pattern. Perl treats empty patterns specially - it reuses the most recent
2376    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2377    effect.
2378    
2379    5. The POSIX interface was broken in that it was just handing over the POSIX
2380    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2381    required a bigger vector, with some working space on the end. This means that
2382    the POSIX wrapper now has to get and free some memory, and copy the results.
2383    
2384    6. Added some simple autoconf support, placing the test data and the
2385    documentation in separate directories, re-organizing some of the
2386    information files, and making it build pcre-config (a GNU standard). Also added
2387    libtool support for building PCRE as a shared library, which is now the
2388    default.
2389    
2390    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2391    09 are not valid octal constants. Single digits will be used for minor values
2392    less than 10.
2393    
2394    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2395    existing programs that set these in the POSIX interface can use PCRE without
2396    modification.
2397    
2398    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2399    return all that pcre_info() returns, plus additional data. The pcre_info()
2400    function is retained for compatibility, but is considered to be obsolete.
2401    
2402    10. Added experimental recursion feature (?R) to handle one common case that
2403    Perl 5.6 will be able to do with (?p{...}).
2404    
2405    11. Added support for POSIX character classes like [:alpha:], which Perl is
2406    adopting.
2407    
2408    
2409    Version 2.08 31-Aug-99
2410    ----------------------
2411    
2412    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2413    trying to match at the startoffset position, but instead was moving forward to
2414    the next newline as if a previous match had failed.
2415    
2416    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2417    and could get into a loop if a null string was matched other than at the start
2418    of the subject.
2419    
2420    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2421    be distinguished at compile time, and for completeness also added PCRE_DATE.
2422    
2423    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2424    in GnuWin32 environments.
2425    
2426    
2427    Version 2.07 29-Jul-99
2428    ----------------------
2429    
2430    1. The documentation is now supplied in plain text form and HTML as well as in
2431    the form of man page sources.
2432    
2433    2. C++ compilers don't like assigning (void *) values to other pointer types.
2434    In particular this affects malloc(). Although there is no problem in Standard
2435    C, I've put in casts to keep C++ compilers happy.
2436    
2437    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2438    should be (const char *).
2439    
2440    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2441    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2442    However, I haven't made this a standard facility. The documentation doesn't
2443    mention it, and the Makefile doesn't support it.
2444    
2445    5. The Makefile now contains an "install" target, with editable destinations at
2446    the top of the file. The pcretest program is not installed.
2447    
2448    6. pgrep -V now gives the PCRE version number and date.
2449    
2450    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2451    causing the entire string to be ignored, instead of just the last character.
2452    
2453    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2454    non-matching string, it can take a very, very long time, even for strings of
2455    quite modest length, because of the nested recursion. PCRE now does better in
2456    some of these cases. It does this by remembering the last required literal
2457    character in the pattern, and pre-searching the subject to ensure it is present
2458    before running the real match. In other words, it applies a heuristic to detect
2459    some types of certain failure quickly, and in the above example, if presented
2460    with a string that has no trailing " it gives "no match" very quickly.
2461    
2462    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2463    other alternatives are tried instead.
2464    
2465    
2466    Version 2.06 09-Jun-99
2467    ----------------------
2468    
2469    1. Change pcretest's output for amount of store used to show just the code
2470    space, because the remainder (the data block) varies in size between 32-bit and
2471    64-bit systems.
2472    
2473    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2474    start matching at. This allows lookbehinds to work when searching for multiple
2475    occurrences in a string.
2476    
2477    3. Added additional options to pcretest for testing multiple occurrences:
2478    
2479       /+   outputs the rest of the string that follows a match
2480       /g   loops for multiple occurrences, using the new startoffset argument
2481       /G   loops for multiple occurrences by passing an incremented pointer
2482    
2483    4. PCRE wasn't doing the "first character" optimization for patterns starting
2484    with \b or \B, though it was doing it for other lookbehind assertions. That is,
2485    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2486    the letter 'x'. On long subject strings, this gives a significant speed-up.
2487    
2488    
2489    Version 2.05 21-Apr-99
2490    ----------------------
2491    
2492    1. Changed the type of magic_number from int to long int so that it works
2493    properly on 16-bit systems.
2494    
2495    2. Fixed a bug which caused patterns starting with .* not to work correctly
2496    when the subject string contained newline characters. PCRE was assuming
2497    anchoring for such patterns in all cases, which is not correct because .* will
2498    not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2499    DOTALL is set at top level; otherwise it knows that patterns starting with .*
2500    must be retried after every newline in the subject.
2501    
2502    
2503    Version 2.04 18-Feb-99
2504    ----------------------
2505    
2506    1. For parenthesized subpatterns with repeats whose minimum was zero, the
2507    computation of the store needed to hold the pattern was incorrect (too large).
2508    If such patterns were nested a few deep, this could multiply and become a real
2509    problem.
2510    
2511    2. Added /M option to pcretest to show the memory requirement of a specific
2512    pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2513    
2514    3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2515    compiled in such a way that the backtracking after subsequent failure was
2516    pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2517    ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2518    
2519    
2520    Version 2.03 02-Feb-99
2521    ----------------------
2522    
2523    1. Fixed typo and small mistake in man page.
2524    
2525    2. Added 4th condition (GPL supersedes if conflict) and created separate
2526    LICENCE file containing the conditions.
2527    
2528    3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2529    Perl, that is the internal \ allows the delimiter to be included in the
2530    pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2531    the final delimiter, add \ to the end of the pattern (to test the error).
2532    
2533    4. Added the convenience functions for extracting substrings after a successful
2534    match. Updated pcretest to make it able to test these functions.
2535    
2536    
2537    Version 2.02 14-Jan-99
2538    ----------------------
2539    
2540    1. Initialized the working variables associated with each extraction so that
2541    their saving and restoring doesn't refer to uninitialized store.
2542    
2543    2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2544    compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2545    fix the problem.
2546    
2547    3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2548    calls, and wasn't printing the correct value for compiling calls. Increased the
2549    default value of LOOPREPEAT, and the number of significant figures in the
2550    times.
2551    
2552    4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2553    
2554    5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2555    a building problem on Windows NT with a FAT file system.
2556    
2557    
2558    Version 2.01 21-Oct-98
2559    ----------------------
2560    
2561    1. Changed the API for pcre_compile() to allow for the provision of a pointer
2562    to character tables built by pcre_maketables() in the current locale. If NULL
2563    is passed, the default tables are used.
2564    
2565    
2566    Version 2.00 24-Sep-98
2567    ----------------------
2568    
2569    1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2570    it any more.
2571    
2572    2. Allow quantification of (?>) groups, and make it work correctly.
2573    
2574    3. The first character computation wasn't working for (?>) groups.
2575    
2576    4. Correct the implementation of \Z (it is permitted to match on the \n at the
2577    end of the subject) and add 5.005's \z, which really does match only at the
2578    very end of the subject.
2579    
2580    5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2581    
2582    6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2583    DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2584    localized options. All options to pcre_study() were also removed.
2585    
2586    7. Add other new features from 5.005:
2587    
2588       $(?<=           positive lookbehind
2589       $(?<!           negative lookbehind
2590       (?imsx-imsx)    added the unsetting capability
2591                       such a setting is global if at outer level; local otherwise
2592       (?imsx-imsx:)   non-capturing groups with option setting
2593       (?(cond)re|re)  conditional pattern matching
2594    
2595       A backreference to itself in a repeated group matches the previous
2596       captured string.
2597    
2598    8. General tidying up of studying (both automatic and via "study")
2599    consequential on the addition of new assertions.
2600    
2601    9. As in 5.005, unlimited repeated groups that could match an empty substring
2602    are no longer faulted at compile time. Instead, the loop is forcibly broken at
2603    runtime if any iteration does actually match an empty substring.
2604    
2605    10. Include the RunTest script in the distribution.
2606    
2607    11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2608    discrepancies, some of which were old and were also with respect to 5.004. They
2609    have now been fixed.
2610    
2611    
2612    Version 1.09 28-Apr-98
2613    ----------------------
2614    
2615    1. A negated single character class followed by a quantifier with a minimum
2616    value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
2617    program crashes, or just wrong answers. This did not apply to negated classes
2618    containing more than one character, or to minima other than one.
2619    
2620    
2621    Version 1.08 27-Mar-98
2622    ----------------------
2623    
2624    1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2625    
2626    2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2627    latter must appear before anything that relies on it in the pattern.
2628    
2629    
2630    Version 1.07 16-Feb-98
2631    ----------------------
2632    
2633    1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2634    repeat of a potentially empty string).
2635    
2636    
2637    Version 1.06 23-Jan-98
2638    ----------------------
2639    
2640    1. Added Markus Oberhumer's little patches for C++.
2641    
2642    2. Literal strings longer than 255 characters were broken.
2643    
2644    
2645    Version 1.05 23-Dec-97
2646    ----------------------
2647    
2648    1. Negated character classes containing more than one character were failing if
2649    PCRE_CASELESS was set at run time.
2650    
2651    
2652  Version 1.04 19-Dec-97  Version 1.04 19-Dec-97
2653  ----------------------  ----------------------

Legend:
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  Added in v.223

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