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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 4.00 17-Feb-03  Version 8.32
5    ------------
6    
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
9    
10    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11        Patch by Daniel Richard G.
12    
13    3.  Single character iterator optimizations in the JIT compiler.
14    
15    
16    Version 8.31 06-July-2012
17    -------------------------
18    
19    1.  Fixing a wrong JIT test case and some compiler warnings.
20    
21    2.  Removed a bashism from the RunTest script.
22    
23    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
24        to unsigned type, result still unsigned" that was given by an MS compiler
25        on encountering the code "-sizeof(xxx)".
26    
27    4.  Partial matching support is added to the JIT compiler.
28    
29    5.  Fixed several bugs concerned with partial matching of items that consist
30        of more than one character:
31    
32        (a) /^(..)\1/ did not partially match "aba" because checking references was
33            done on an "all or nothing" basis. This also applied to repeated
34            references.
35    
36        (b) \R did not give a hard partial match if \r was found at the end of the
37            subject.
38    
39        (c) \X did not give a hard partial match after matching one or more
40            characters at the end of the subject.
41    
42        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
43            a partial match for the string "\r".
44    
45        (e) When newline was set to CRLF, the metacharacter "." did not recognize
46            a partial match for a CR character at the end of the subject string.
47    
48    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
49        running pcretest, the text "(JIT)" added to the output whenever JIT is
50        actually used to run the match.
51    
52    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
53        or /S+[+] with a digit between 1 and 7.
54    
55    8.  OP_NOT now supports any UTF character not just single-byte ones.
56    
57    9.  (*MARK) control verb is now supported by the JIT compiler.
58    
59    10. The command "./RunTest list" lists the available tests without actually
60        running any of them. (Because I keep forgetting what they all are.)
61    
62    11. Add PCRE_INFO_MAXLOOKBEHIND.
63    
64    12. Applied a (slightly modified) user-supplied patch that improves performance
65        when the heap is used for recursion (compiled with --disable-stack-for-
66        recursion). Instead of malloc and free for each heap frame each time a
67        logical recursion happens, frames are retained on a chain and re-used where
68        possible. This sometimes gives as much as 30% improvement.
69    
70    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
71        call.
72    
73    14. As documented, (*COMMIT) is now confined to within a positive assertion.
74    
75    15. It is now possible to link pcretest with libedit as an alternative to
76        libreadline.
77    
78    16. (*COMMIT) control verb is now supported by the JIT compiler.
79    
80    17. The Unicode data tables have been updated to Unicode 6.1.0.
81    
82    18. Added --file-list option to pcregrep.
83    
84    19. Added binary file support to pcregrep, including the -a, --binary-files,
85        -I, and --text options.
86    
87    20. The madvise function is renamed for posix_madvise for QNX compatibility
88        reasons. Fixed by Giuseppe D'Angelo.
89    
90    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
91    
92    22. Changed the option for creating symbolic links for 16-bit man pages from
93        -s to -sf so that re-installing does not cause issues.
94    
95    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
96    
97    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
98        matches in certain environments (the workspace was not being correctly
99        retained). Also added to pcre_dfa_exec() a simple plausibility check on
100        some of the workspace data at the beginning of a restart.
101    
102    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
103        was not doing so when it should - probably a typo introduced by SVN 528
104        (change 8.10/14).
105    
106    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
107        \w+ when the character tables indicated that \x{c4} was a word character.
108        There were several related cases, all because the tests for doing a table
109        lookup were testing for characters less than 127 instead of 255.
110    
111    27. If a pattern contains capturing parentheses that are not used in a match,
112        their slots in the ovector are set to -1. For those that are higher than
113        any matched groups, this happens at the end of processing. In the case when
114        there were back references that the ovector was too small to contain
115        (causing temporary malloc'd memory to be used during matching), and the
116        highest capturing number was not used, memory off the end of the ovector
117        was incorrectly being set to -1. (It was using the size of the temporary
118        memory instead of the true size.)
119    
120    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
121        ovector size, it uses memory at the end of the block that it has got.
122    
123    29. Check for an overlong MARK name and give an error at compile time. The
124        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
125    
126    30. JIT compiler update.
127    
128    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
129        Rill for the patch.
130    
131    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
132    
133    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
134    
135    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
136        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
137        was enabled.
138    
139    35. Improve JIT code generation for greedy plus quantifier.
140    
141    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
142        1 to "aa" instead of to an empty string. The bug affected repeated groups
143        that could potentially match an empty string.
144    
145    37. Optimizing single character iterators in JIT.
146    
147    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
148        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
149        codepoints that are too big for the mode are faulted, and in a UTF mode,
150        disallowed codepoints are also faulted.
151    
152    39. If PCRE was compiled with UTF support, in three places in the DFA
153        matcher there was code that should only have been obeyed in UTF mode, but
154        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
155        processing when bytes with values greater than 127 were present. In 16-bit
156        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
157        both cases the values are those that cannot be the first data item in a UTF
158        character. The three items that might have provoked this were recursions,
159        possessively repeated groups, and atomic groups.
160    
161    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
162        and pcregrep, because some OS require shared objects to be explicitly
163        passed to ld, causing the link step to fail if they are not.
164    
165    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
166        mode, patterns that started with \h* or \R* might be incorrectly matched.
167    
168    
169    Version 8.30 04-February-2012
170    -----------------------------
171    
172    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
173        name is defined in ctype.h.
174    
175    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
176        only in quite long subpatterns.
177    
178    3.  Removed the function pcre_info(), which has been obsolete and deprecated
179        since it was replaced by pcre_fullinfo() in February 2000.
180    
181    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
182        match a (*MARK), and the match failed at the start of the subject, a
183        reference to memory before the start of the subject could occur. This bug
184        was introduced by fix 17 of release 8.21.
185    
186    5.  A reference to an unset group with zero minimum repetition was giving
187        totally wrong answers (in non-JavaScript-compatibility mode). For example,
188        /(another)?(\1?)test/ matched against "hello world test". This bug was
189        introduced in release 8.13.
190    
191    6.  Add support for 16-bit character strings (a large amount of work involving
192        many changes and refactorings).
193    
194    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
195        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
196        from a file.
197    
198    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
199        rounding is not applied in this particular case).
200    
201    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
202        if they appear, or are escaped, in patterns.
203    
204    10. Get rid of a number of -Wunused-but-set-variable warnings.
205    
206    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
207        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
208        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
209        also returns the mark "x". This bug applied to capturing parentheses,
210        non-capturing parentheses, and atomic parentheses. It also applied to some
211        assertions.
212    
213    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
214        information out of configure.ac instead of relying on pcre.h.generic, which
215        is not stored in the repository.
216    
217    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
218        -lreadline.
219    
220    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
221    
222    15. Applied Graycode's patch to put the top-level frame on the stack rather
223        than the heap when not using the stack for recursion. This gives a
224        performance improvement in many cases when recursion is not deep.
225    
226    16. Experimental code added to "pcretest -C" to output the stack frame size.
227    
228    
229    Version 8.21 12-Dec-2011
230    ------------------------
231    
232    1.  Updating the JIT compiler.
233    
234    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
235        are added as well.
236    
237    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
238        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
239        calling _pcre_jit_exec. Some extra comments are added.
240    
241    4.  (*MARK) settings inside atomic groups that do not contain any capturing
242        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
243        was introduced by change 18 for 8.20.
244    
245    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
246        ECMA-262 standard.
247    
248    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
249        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
250        This bug was probably introduced by change 9 of 8.13.
251    
252    7.  While fixing 6 above, I noticed that a number of other items were being
253        incorrectly rejected as "not fixed length". This arose partly because newer
254        opcodes had not been added to the fixed-length checking code. I have (a)
255        corrected the bug and added tests for these items, and (b) arranged for an
256        error to occur if an unknown opcode is encountered while checking for fixed
257        length instead of just assuming "not fixed length". The items that were
258        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
259        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
260        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
261    
262    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
263        being incorrectly compiled and would have given unpredicatble results.
264    
265    9.  A possessively repeated subpattern with minimum repeat count greater than
266        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
267        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
268        the first (A) could occur when it should not.
269    
270    10. Add a cast and remove a redundant test from the code.
271    
272    11. JIT should use pcre_malloc/pcre_free for allocation.
273    
274    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
275        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
276        is anything other than /usr, -L is still shown).
277    
278    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
279    
280    14. Perl does not support \N without a following name in a [] class; PCRE now
281        also gives an error.
282    
283    15. If a forward reference was repeated with an upper limit of around 2000,
284        it caused the error "internal error: overran compiling workspace". The
285        maximum number of forward references (including repeats) was limited by the
286        internal workspace, and dependent on the LINK_SIZE. The code has been
287        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
288        the default depends on LINK_SIZE. There is a new upper limit (for safety)
289        of around 200,000 forward references. While doing this, I also speeded up
290        the filling in of repeated forward references.
291    
292    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
293        incorrectly expecting the subject to contain another "a" after the start.
294    
295    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
296        in the match, the SKIP should be ignored. This was not happening; instead
297        the SKIP was being treated as NOMATCH. For patterns such as
298        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
299        tested.
300    
301    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
302        now much more compatible with Perl, in particular in cases where the result
303        is a non-match for a non-anchored pattern. For example, if
304        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
305        "m", where previously it did not return a name. A side effect of this
306        change is that for partial matches, the last encountered mark name is
307        returned, as for non matches. A number of tests that were previously not
308        Perl-compatible have been moved into the Perl-compatible test files. The
309        refactoring has had the pleasing side effect of removing one argument from
310        the match() function, thus reducing its stack requirements.
311    
312    19. If the /S+ option was used in pcretest to study a pattern using JIT,
313        subsequent uses of /S (without +) incorrectly behaved like /S+.
314    
315    21. Retrieve executable code size support for the JIT compiler and fixing
316        some warnings.
317    
318    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
319        not work when the shorter character appeared right at the end of the
320        subject string.
321    
322    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
323        systems.
324    
325    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
326        output it when the /M option is used in pcretest.
327    
328    25. The CheckMan script was not being included in the distribution. Also, added
329        an explicit "perl" to run Perl scripts from the PrepareRelease script
330        because this is reportedly needed in Windows.
331    
332    26. If study data was being save in a file and studying had not found a set of
333        "starts with" bytes for the pattern, the data written to the file (though
334        never used) was taken from uninitialized memory and so caused valgrind to
335        complain.
336    
337    27. Updated RunTest.bat as provided by Sheri Pierce.
338    
339    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
340    
341    29. Computation of memory usage for the table of capturing group names was
342        giving an unnecessarily large value.
343    
344    
345    Version 8.20 21-Oct-2011
346    ------------------------
347    
348    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
349        a POSIX class. After further experiments with Perl, which convinced me that
350        Perl has bugs and confusions, a closing square bracket is no longer allowed
351        in a POSIX name. This bug also affected patterns with classes that started
352        with full stops.
353    
354    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
355        captured substring, but while checking the failing first alternative,
356        substring 1 is temporarily captured. If the output vector supplied to
357        pcre_exec() was not big enough for this capture, the yield of the function
358        was still zero ("insufficient space for captured substrings"). This cannot
359        be totally fixed without adding another stack variable, which seems a lot
360        of expense for a edge case. However, I have improved the situation in cases
361        such as /(a)(b)x|abc/ matched against "abc", where the return code
362        indicates that fewer than the maximum number of slots in the ovector have
363        been set.
364    
365    3.  Related to (2) above: when there are more back references in a pattern than
366        slots in the output vector, pcre_exec() uses temporary memory during
367        matching, and copies in the captures as far as possible afterwards. It was
368        using the entire output vector, but this conflicts with the specification
369        that only 2/3 is used for passing back captured substrings. Now it uses
370        only the first 2/3, for compatibility. This is, of course, another edge
371        case.
372    
373    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
374        main code base, and can be used by building with --enable-jit. When this is
375        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
376        runtime --no-jit option is given.
377    
378    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
379        ovector, the return from the function was zero, implying that there were
380        other matches that did not fit. The correct "exactly full" value is now
381        returned.
382    
383    6.  If a subpattern that was called recursively or as a subroutine contained
384        (*PRUNE) or any other control that caused it to give a non-standard return,
385        invalid errors such as "Error -26 (nested recursion at the same subject
386        position)" or even infinite loops could occur.
387    
388    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
389        computing the minimum length on reaching *ACCEPT, and so ended up with the
390        wrong value of 1 rather than 0. Further investigation indicates that
391        computing a minimum subject length in the presence of *ACCEPT is difficult
392        (think back references, subroutine calls), and so I have changed the code
393        so that no minimum is registered for a pattern that contains *ACCEPT.
394    
395    8.  If (*THEN) was present in the first (true) branch of a conditional group,
396        it was not handled as intended. [But see 16 below.]
397    
398    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
399        Sheri Pierce.
400    
401    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
402        the first byte in a match must be "a".
403    
404    11. Change 17 for 8.13 increased the recursion depth for patterns like
405        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
406        pattern contains any instances of (*THEN). If it does not, the old
407        optimizations are restored. It would be nice to do this on a per-group
408        basis, but at the moment that is not feasible.
409    
410    12. In some environments, the output of pcretest -C is CRLF terminated. This
411        broke RunTest's code that checks for the link size. A single white space
412        character after the value is now allowed for.
413    
414    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
415        For "fr", it uses the Windows-specific input and output files.
416    
417    14. If (*THEN) appeared in a group that was called recursively or as a
418        subroutine, it did not work as intended. [But see next item.]
419    
420    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
421        pattern fragments (but not containing any | characters). If A and B are
422        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
423        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
424        D. In other words, Perl considers parentheses that do not contain any |
425        characters to be part of a surrounding alternative, whereas PCRE was
426        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
427        differently. PCRE now behaves in the same way as Perl, except in the case
428        of subroutine/recursion calls such as (?1) which have in any case always
429        been different (but PCRE had them first :-).
430    
431    16. Related to 15 above: Perl does not treat the | in a conditional group as
432        creating alternatives. Such a group is treated in the same way as an
433        ordinary group without any | characters when processing (*THEN). PCRE has
434        been changed to match Perl's behaviour.
435    
436    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
437        RunGrepTest script failed.
438    
439    18. Change 22 for version 13 caused atomic groups to use more stack. This is
440        inevitable for groups that contain captures, but it can lead to a lot of
441        stack use in large patterns. The old behaviour has been restored for atomic
442        groups that do not contain any capturing parentheses.
443    
444    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
445        suppress the check for a minimum subject length at run time. (If it was
446        given to pcre_exec() or pcre_dfa_exec() it did work.)
447    
448    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
449        fail to work when decoding hex characters in data strings in EBCDIC
450        environments.
451    
452    21. It appears that in at least one Mac OS environment, the isxdigit() function
453        is implemented as a macro that evaluates to its argument more than once,
454        contravening the C 90 Standard (I haven't checked a later standard). There
455        was an instance in pcretest which caused it to go wrong when processing
456        \x{...} escapes in subject strings. The has been rewritten to avoid using
457        things like p++ in the argument of isxdigit().
458    
459    
460    Version 8.13 16-Aug-2011
461    ------------------------
462    
463    1.  The Unicode data tables have been updated to Unicode 6.0.0.
464    
465    2.  Two minor typos in pcre_internal.h have been fixed.
466    
467    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
468        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
469        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
470    
471    4.  There were a number of related bugs in the code for matching backrefences
472        caselessly in UTF-8 mode when codes for the characters concerned were
473        different numbers of bytes. For example, U+023A and U+2C65 are an upper
474        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
475        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
476        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
477        2-byte code at the end of the subject (it thought there wasn't enough data
478        left).
479    
480    5.  Comprehensive information about what went wrong is now returned by
481        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
482        as the output vector has at least 2 elements. The offset of the start of
483        the failing character and a reason code are placed in the vector.
484    
485    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
486        now returned is for the first byte of the failing character, instead of the
487        last byte inspected. This is an incompatible change, but I hope it is small
488        enough not to be a problem. It makes the returned offset consistent with
489        pcre_exec() and pcre_dfa_exec().
490    
491    7.  pcretest now gives a text phrase as well as the error number when
492        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
493        failure, the offset and reason code are output.
494    
495    8.  When \R was used with a maximizing quantifier it failed to skip backwards
496        over a \r\n pair if the subsequent match failed. Instead, it just skipped
497        back over a single character (\n). This seems wrong (because it treated the
498        two characters as a single entity when going forwards), conflicts with the
499        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
500        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
501        has been changed.
502    
503    9.  Some internal refactoring has changed the processing so that the handling
504        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
505        time (the PCRE_DOTALL option was changed this way some time ago: version
506        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
507        which was always a bit of a fudge. It also means that there is one less
508        argument for the match() function, which reduces its stack requirements
509        slightly. This change also fixes an incompatibility with Perl: the pattern
510        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
511    
512    10. More internal refactoring has drastically reduced the number of recursive
513        calls to match() for possessively repeated groups such as (abc)++ when
514        using pcre_exec().
515    
516    11. While implementing 10, a number of bugs in the handling of groups were
517        discovered and fixed:
518    
519        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
520        (a|)*(?1) gave a compile-time internal error.
521        ((a|)+)+  did not notice that the outer group could match an empty string.
522        (^a|^)+   was not marked as anchored.
523        (.*a|.*)+ was not marked as matching at start or after a newline.
524    
525    12. Yet more internal refactoring has removed another argument from the match()
526        function. Special calls to this function are now indicated by setting a
527        value in a variable in the "match data" data block.
528    
529    13. Be more explicit in pcre_study() instead of relying on "default" for
530        opcodes that mean there is no starting character; this means that when new
531        ones are added and accidentally left out of pcre_study(), testing should
532        pick them up.
533    
534    14. The -s option of pcretest has been documented for ages as being an old
535        synonym of -m (show memory usage). I have changed it to mean "force study
536        for every regex", that is, assume /S for every regex. This is similar to -i
537        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
538        using it. It makes it easier to run collections of tests with and without
539        study enabled, and thereby test pcre_study() more easily. All the standard
540        tests are now run with and without -s (but some patterns can be marked as
541        "never study" - see 20 below).
542    
543    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
544        restoration of the capturing data to the outer values was not happening
545        correctly.
546    
547    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
548        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
549        pattern had matched an empty string, and so incorrectly returned a no
550        match.
551    
552    17. There was optimizing code for the last branch of non-capturing parentheses,
553        and also for the obeyed branch of a conditional subexpression, which used
554        tail recursion to cut down on stack usage. Unfortunately, now that there is
555        the possibility of (*THEN) occurring in these branches, tail recursion is
556        no longer possible because the return has to be checked for (*THEN). These
557        two optimizations have therefore been removed. [But see 8.20/11 above.]
558    
559    18. If a pattern containing \R was studied, it was assumed that \R always
560        matched two bytes, thus causing the minimum subject length to be
561        incorrectly computed because \R can also match just one byte.
562    
563    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
564        was incorrectly computed.
565    
566    20. If /S is present twice on a test pattern in pcretest input, it now
567        *disables* studying, thereby overriding the use of -s on the command line
568        (see 14 above). This is necessary for one or two tests to keep the output
569        identical in both cases.
570    
571    21. When (*ACCEPT) was used in an assertion that matched an empty string and
572        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
573    
574    22. When an atomic group that contained a capturing parenthesis was
575        successfully matched, but the branch in which it appeared failed, the
576        capturing was not being forgotten if a higher numbered group was later
577        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
578        group 1 to "a", when in fact it should be unset. This applied to multi-
579        branched capturing and non-capturing groups, repeated or not, and also to
580        positive assertions (capturing in negative assertions does not happen
581        in PCRE) and also to nested atomic groups.
582    
583    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
584        subject after a captured substring, to make it easier to tell which of a
585        number of identical substrings has been captured.
586    
587    24. The way atomic groups are processed by pcre_exec() has been changed so that
588        if they are repeated, backtracking one repetition now resets captured
589        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
590        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
591        "aaa". Previously, it would have been "a". As part of this code
592        refactoring, the way recursive calls are handled has also been changed.
593    
594    25. If an assertion condition captured any substrings, they were not passed
595        back unless some other capturing happened later. For example, if
596        (?(?=(a))a) was matched against "a", no capturing was returned.
597    
598    26. When studying a pattern that contained subroutine calls or assertions,
599        the code for finding the minimum length of a possible match was handling
600        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
601        group 1 called group 2 while simultaneously a separate group 2 called group
602        1). A stack overflow occurred in this case. I have fixed this by limiting
603        the recursion depth to 10.
604    
605    27. Updated RunTest.bat in the distribution to the version supplied by Tom
606        Fortmann. This supports explicit test numbers on the command line, and has
607        argument validation and error reporting.
608    
609    28. An instance of \X with an unlimited repeat could fail if at any point the
610        first character it looked at was a mark character.
611    
612    29. Some minor code refactoring concerning Unicode properties and scripts
613        should reduce the stack requirement of match() slightly.
614    
615    30. Added the '=' option to pcretest to check the setting of unused capturing
616        slots at the end of the pattern, which are documented as being -1, but are
617        not included in the return count.
618    
619    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
620        compiled something random. Now it gives a compile-time error (as does
621        Perl).
622    
623    32. A *MARK encountered during the processing of a positive assertion is now
624        recorded and passed back (compatible with Perl).
625    
626    33. If --only-matching or --colour was set on a pcregrep call whose pattern
627        had alternative anchored branches, the search for a second match in a line
628        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
629        matched the line "0102" twice. The same bug affected patterns that started
630        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
631        twice.
632    
633    34. Previously, PCRE did not allow quantification of assertions. However, Perl
634        does, and because of capturing effects, quantifying parenthesized
635        assertions may at times be useful. Quantifiers are now allowed for
636        parenthesized assertions.
637    
638    35. A minor code tidy in pcre_compile() when checking options for \R usage.
639    
640    36. \g was being checked for fancy things in a character class, when it should
641        just be a literal "g".
642    
643    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
644        appearance of a nested POSIX class supersedes an apparent external class.
645        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
646        unescaped square brackets may also appear as part of class names. For
647        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
648        more like Perl. (But see 8.20/1 above.)
649    
650    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
651        was because it thought it was \N{name}, which is not supported).
652    
653    39. Add minix to OS list not supporting the -S option in pcretest.
654    
655    40. PCRE tries to detect cases of infinite recursion at compile time, but it
656        cannot analyze patterns in sufficient detail to catch mutual recursions
657        such as ((?1))((?2)). There is now a runtime test that gives an error if a
658        subgroup is called recursively as a subpattern for a second time at the
659        same position in the subject string. In previous releases this might have
660        been caught by the recursion limit, or it might have run out of stack.
661    
662    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
663        happen only once. PCRE was, however incorrectly giving a compile time error
664        "recursive call could loop indefinitely" because it cannot analyze the
665        pattern in sufficient detail. The compile time test no longer happens when
666        PCRE is compiling a conditional subpattern, but actual runaway loops are
667        now caught at runtime (see 40 above).
668    
669    42. It seems that Perl allows any characters other than a closing parenthesis
670        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
671        has been changed to be the same.
672    
673    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
674        as not to get warnings when autogen.sh is called. Also changed
675        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
676    
677    44. To help people who use pcregrep to scan files containing exceedingly long
678        lines, the following changes have been made:
679    
680        (a) The default value of the buffer size parameter has been increased from
681            8K to 20K. (The actual buffer used is three times this size.)
682    
683        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
684            PCRE is built.
685    
686        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
687            to be set at run time.
688    
689        (d) Numerical values in pcregrep options can be followed by K or M, for
690            example --buffer-size=50K.
691    
692        (e) If a line being scanned overflows pcregrep's buffer, an error is now
693            given and the return code is set to 2.
694    
695    45. Add a pointer to the latest mark to the callout data block.
696    
697    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
698        partial match of an empty string instead of no match. This was specific to
699        the use of ".".
700    
701    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
702        complete match instead of a partial match. This bug was dependent on both
703        the PCRE_UTF8 and PCRE_DOTALL options being set.
704    
705    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
706        starting byte set, because \b was not being ignored.
707    
708    
709    Version 8.12 15-Jan-2011
710    ------------------------
711    
712    1.  Fixed some typos in the markup of the man pages, and wrote a script that
713        checks for such things as part of the documentation building process.
714    
715    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
716        --match-limit and --recursion-limit options (added for 8.11). In
717        particular, this made one of the standard tests fail. (The integer value
718        went into the wrong half of a long int.)
719    
720    3.  If the --colour option was given to pcregrep with -v (invert match), it
721        did strange things, either producing crazy output, or crashing. It should,
722        of course, ignore a request for colour when reporting lines that do not
723        match.
724    
725    4.  Another pcregrep bug caused similar problems if --colour was specified with
726        -M (multiline) and the pattern match finished with a line ending.
727    
728    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
729        matched in multiline mode, the following line was shown as part of the
730        match. This seems wrong, so I have changed it.
731    
732    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
733        the check for further matches in the same line (so they could be coloured)
734        to overrun the end of the current line. If another match was found, it was
735        incorrectly shown (and then shown again when found in the next line).
736    
737    7.  If pcregrep was compiled under Windows, there was a reference to the
738        function pcregrep_exit() before it was defined. I am assuming this was
739        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
740        reported by a user. I've moved the definition above the reference.
741    
742    
743    Version 8.11 10-Dec-2010
744    ------------------------
745    
746    1.  (*THEN) was not working properly if there were untried alternatives prior
747        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
748        backtracked to try for "b" instead of moving to the next alternative branch
749        at the same level (in this case, to look for "c"). The Perl documentation
750        is clear that when (*THEN) is backtracked onto, it goes to the "next
751        alternative in the innermost enclosing group".
752    
753    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
754        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
755        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
756        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
757        (*THEN).
758    
759    3.  If \s appeared in a character class, it removed the VT character from
760        the class, even if it had been included by some previous item, for example
761        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
762        of \s, but is part of the POSIX "space" class.)
763    
764    4.  A partial match never returns an empty string (because you can always
765        match an empty string at the end of the subject); however the checking for
766        an empty string was starting at the "start of match" point. This has been
767        changed to the "earliest inspected character" point, because the returned
768        data for a partial match starts at this character. This means that, for
769        example, /(?<=abc)def/ gives a partial match for the subject "abc"
770        (previously it gave "no match").
771    
772    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
773        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
774        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
775        has an implication that the given string is incomplete (because a partial
776        match is preferred over a full match). For this reason, these items now
777        give a partial match in this situation. [Aside: previously, the one case
778        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
779        match rather than a full match, which was wrong by the old rules, but is
780        now correct.]
781    
782    6.  There was a bug in the handling of #-introduced comments, recognized when
783        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
784        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
785        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
786        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
787        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
788        places in pcre_compile().
789    
790    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
791        comments when looking ahead for named forward references to subpatterns,
792        the only newline sequence it recognized was NL. It now handles newlines
793        according to the set newline convention.
794    
795    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
796        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
797        cater for a lack of strerror(). These oversights have been fixed.
798    
799    9.  Added --match-limit and --recursion-limit to pcregrep.
800    
801    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
802    
803    11. When the -o option was used, pcregrep was setting a return code of 1, even
804        when matches were found, and --line-buffered was not being honoured.
805    
806    12. Added an optional parentheses number to the -o and --only-matching options
807        of pcregrep.
808    
809    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
810        can match an empty string. The code to do it in pcretest and pcredemo
811        needed fixing:
812    
813        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
814            only one byte after an empty string match just before CRLF (this case
815            just got forgotten; "any" and "anycrlf" were OK).
816    
817        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
818            mode when an empty string match preceded an ASCII character followed by
819            a non-ASCII character. (The code for advancing by one character rather
820            than one byte was nonsense.)
821    
822        (c) The pcredemo.c sample program did not have any code at all to handle
823            the cases when CRLF is a valid newline sequence.
824    
825    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
826        as a starting offset was within the subject string. There is now a new
827        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
828        negative or greater than the length of the string. In order to test this,
829        pcretest is extended to allow the setting of negative starting offsets.
830    
831    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
832        starting offset points to the beginning of a UTF-8 character was
833        unnecessarily clumsy. I tidied it up.
834    
835    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
836        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
837    
838    17. Nobody had reported that the --include_dir option, which was added in
839        release 7.7 should have been called --include-dir (hyphen, not underscore)
840        for compatibility with GNU grep. I have changed it to --include-dir, but
841        left --include_dir as an undocumented synonym, and the same for
842        --exclude-dir, though that is not available in GNU grep, at least as of
843        release 2.5.4.
844    
845    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
846        characters from a string of bytes) have been redefined so as not to use
847        loops, in order to improve performance in some environments. At the same
848        time, I abstracted some of the common code into auxiliary macros to save
849        repetition (this should not affect the compiled code).
850    
851    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
852        compile-time error is now given if \c is not followed by an ASCII
853        character, that is, a byte less than 128. (In EBCDIC mode, the code is
854        different, and any byte value is allowed.)
855    
856    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
857        START_OPTIMIZE option, which is now allowed at compile time - but just
858        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
859        to pcregrep and other applications that have no direct access to PCRE
860        options. The new /Y option in pcretest sets this option when calling
861        pcre_compile().
862    
863    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
864        back references. Groups containing recursive back references were forced to
865        be atomic by that change, but in the case of named groups, the amount of
866        memory required was incorrectly computed, leading to "Failed: internal
867        error: code overflow". This has been fixed.
868    
869    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
870        pcretest.c, to avoid build problems in some Borland environments.
871    
872    
873    Version 8.10 25-Jun-2010
874    ------------------------
875    
876    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
877        THEN.
878    
879    2.  (*ACCEPT) was not working when inside an atomic group.
880    
881    3.  Inside a character class, \B is treated as a literal by default, but
882        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
883        causes the error). The code is unchanged, but I tidied the documentation.
884    
885    4.  Inside a character class, PCRE always treated \R and \X as literals,
886        whereas Perl faults them if its -w option is set. I have changed PCRE so
887        that it faults them when PCRE_EXTRA is set.
888    
889    5.  Added support for \N, which always matches any character other than
890        newline. (It is the same as "." when PCRE_DOTALL is not set.)
891    
892    6.  When compiling pcregrep with newer versions of gcc which may have
893        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
894        declared with attribute warn_unused_result" were given. Just casting the
895        result to (void) does not stop the warnings; a more elaborate fudge is
896        needed. I've used a macro to implement this.
897    
898    7.  Minor change to pcretest.c to avoid a compiler warning.
899    
900    8.  Added four artifical Unicode properties to help with an option to make
901        \s etc use properties (see next item). The new properties are: Xan
902        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
903    
904    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
905        use Unicode properties. (*UCP) at the start of a pattern can be used to set
906        this option. Modified pcretest to add /W to test this facility. Added
907        REG_UCP to make it available via the POSIX interface.
908    
909    10. Added --line-buffered to pcregrep.
910    
911    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
912        studied, and the match started with a letter with a code point greater than
913        127 whose first byte was different to the first byte of the other case of
914        the letter, the other case of this starting letter was not recognized
915        (#976).
916    
917    12. If a pattern that was studied started with a repeated Unicode property
918        test, for example, \p{Nd}+, there was the theoretical possibility of
919        setting up an incorrect bitmap of starting bytes, but fortunately it could
920        not have actually happened in practice until change 8 above was made (it
921        added property types that matched character-matching opcodes).
922    
923    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
924        possible starting bytes for non-anchored patterns.
925    
926    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
927        \R, and also a number of cases that involve Unicode properties, both
928        explicit and implicit when PCRE_UCP is set.
929    
930    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
931        input, it could crash or give wrong results if characters with values
932        greater than 0xc0 were present in the subject string. (Detail: it assumed
933        UTF-8 input when processing these items.)
934    
935    16. Added a lot of (int) casts to avoid compiler warnings in systems where
936        size_t is 64-bit (#991).
937    
938    17. Added a check for running out of memory when PCRE is compiled with
939        --disable-stack-for-recursion (#990).
940    
941    18. If the last data line in a file for pcretest does not have a newline on
942        the end, a newline was missing in the output.
943    
944    19. The default pcre_chartables.c file recognizes only ASCII characters (values
945        less than 128) in its various bitmaps. However, there is a facility for
946        generating tables according to the current locale when PCRE is compiled. It
947        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
948        characters, are recognized by isspace() and therefore were getting set in
949        these tables, and indeed these tables seem to approximate to ISO 8859. This
950        caused a problem in UTF-8 mode when pcre_study() was used to create a list
951        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
952        which of course cannot start UTF-8 characters. I have changed the code so
953        that only real ASCII characters (less than 128) and the correct starting
954        bytes for UTF-8 encodings are set for characters greater than 127 when in
955        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
956        altogether.)
957    
958    20. Added the /T option to pcretest so as to be able to run tests with non-
959        standard character tables, thus making it possible to include the tests
960        used for 19 above in the standard set of tests.
961    
962    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
963        reference to a subpattern the other side of a comment that contains an
964        opening parenthesis caused either an internal compiling error, or a
965        reference to the wrong subpattern.
966    
967    
968    Version 8.02 19-Mar-2010
969    ------------------------
970    
971    1.  The Unicode data tables have been updated to Unicode 5.2.0.
972    
973    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
974        configured.
975    
976    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
977        original author of that file, following a query about its status.
978    
979    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
980        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
981    
982    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
983        quantifier applied to a forward-referencing subroutine call, could compile
984        incorrect code or give the error "internal error: previously-checked
985        referenced subpattern not found".
986    
987    6.  Both MS Visual Studio and Symbian OS have problems with initializing
988        variables to point to external functions. For these systems, therefore,
989        pcre_malloc etc. are now initialized to local functions that call the
990        relevant global functions.
991    
992    7.  There were two entries missing in the vectors called coptable and poptable
993        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
994        I've fixed the data, and added a kludgy way of testing at compile time that
995        the lengths are correct (equal to the number of opcodes).
996    
997    8.  Following on from 7, I added a similar kludge to check the length of the
998        eint vector in pcreposix.c.
999    
1000    9.  Error texts for pcre_compile() are held as one long string to avoid too
1001        much relocation at load time. To find a text, the string is searched,
1002        counting zeros. There was no check for running off the end of the string,
1003        which could happen if a new error number was added without updating the
1004        string.
1005    
1006    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1007    
1008    11. \K was not working if it appeared in an atomic group or in a group that
1009        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1010        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1011        the assertion is positive, but not if it is negative.
1012    
1013    12. Change 11 fortuitously reduced the size of the stack frame used in the
1014        "match()" function of pcre_exec.c by one pointer. Forthcoming
1015        implementation of support for (*MARK) will need an extra pointer on the
1016        stack; I have reserved it now, so that the stack frame size does not
1017        decrease.
1018    
1019    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1020        item in branch that calls a recursion is a subroutine call - as in the
1021        second branch in the above example - was incorrectly given the compile-
1022        time error "recursive call could loop indefinitely" because pcre_compile()
1023        was not correctly checking the subroutine for matching a non-empty string.
1024    
1025    14. The checks for overrunning compiling workspace could trigger after an
1026        overrun had occurred. This is a "should never occur" error, but it can be
1027        triggered by pathological patterns such as hundreds of nested parentheses.
1028        The checks now trigger 100 bytes before the end of the workspace.
1029    
1030    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1031    
1032    
1033    Version 8.01 19-Jan-2010
1034    ------------------------
1035    
1036    1.  If a pattern contained a conditional subpattern with only one branch (in
1037        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1038        computed the wrong minimum data length (which is of course zero for such
1039        subpatterns). This could cause incorrect "no match" results.
1040    
1041    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1042        the pattern is reset in the first branch, pcre_compile() failed with
1043        "internal error: code overflow at offset...". This happened only when
1044        the reset was to the original external option setting. (An optimization
1045        abstracts leading options settings into an external setting, which was the
1046        cause of this.)
1047    
1048    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1049        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1050        assertion pattern did not match (meaning that the assertion was true), it
1051        was incorrectly treated as false if the SKIP had been reached during the
1052        matching. This also applied to assertions used as conditions.
1053    
1054    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1055        assertion subpattern, including such a pattern used as a condition,
1056        unpredictable results occurred, instead of the error return
1057        PCRE_ERROR_DFA_UITEM.
1058    
1059    5.  The C++ GlobalReplace function was not working like Perl for the special
1060        situation when an empty string is matched. It now does the fancy magic
1061        stuff that is necessary.
1062    
1063    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1064        removed. (These were left over from very, very early versions of PCRE.)
1065    
1066    7.  Some cosmetic changes to the code to make life easier when compiling it
1067        as part of something else:
1068    
1069        (a) Change DEBUG to PCRE_DEBUG.
1070    
1071        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1072            called "current" as "current_branch", to prevent a collision with the
1073            Linux macro when compiled as a kernel module.
1074    
1075        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1076            prevent a collision with the Linux macro when compiled as a kernel
1077            module.
1078    
1079    8.  In pcre_compile() there are some checks for integer overflows that used to
1080        cast potentially large values to (double). This has been changed to that
1081        when building, a check for int64_t is made, and if it is found, it is used
1082        instead, thus avoiding the use of floating point arithmetic. (There is no
1083        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1084        double.
1085    
1086    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1087        2005 (difference between two addresses compared to an unsigned value).
1088    
1089    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1090        custom one, because of the following reported problem in Windows:
1091    
1092          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1093              under Win32.
1094          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1095              therefore missing the function definition.
1096          - The compiler thus generates a "C" signature for the test function.
1097          - The linker fails to find the "C" function.
1098          - PCRE fails to configure if asked to do so against libbz2.
1099    
1100    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1101        messages were output:
1102    
1103          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1104          rerunning libtoolize, to keep the correct libtool macros in-tree.
1105          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1106    
1107        I have done both of these things.
1108    
1109    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1110        most of the time, it *can* run out if it is given a pattern that contains a
1111        runaway infinite recursion. I updated the discussion in the pcrestack man
1112        page.
1113    
1114    13. Now that we have gone to the x.xx style of version numbers, the minor
1115        version may start with zero. Using 08 or 09 is a bad idea because users
1116        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1117        interpreted as invalid octal numbers. I've updated the previous comment in
1118        configure.ac, and also added a check that gives an error if 08 or 09 are
1119        used.
1120    
1121    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1122        causing partial matching to fail when the end of the subject matched \W
1123        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1124    
1125    15. There were some discrepancies between the declarations in pcre_internal.h
1126        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1127        their definitions. The declarations used "const uschar *" and the
1128        definitions used USPTR. Even though USPTR is normally defined as "const
1129        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1130        reported that: "This difference in casting confuses some C++ compilers, for
1131        example, SunCC recognizes above declarations as different functions and
1132        generates broken code for hbpcre." I have changed the declarations to use
1133        USPTR.
1134    
1135    16. GNU libtool is named differently on some systems. The autogen.sh script now
1136        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1137        (FreeBSD).
1138    
1139    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1140        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1141        comment: "Figure out how to create a longlong from a string: strtoll and
1142        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1143        instance, but it only takes 2 args instead of 3!"
1144    
1145    18. A subtle bug concerned with back references has been fixed by a change of
1146        specification, with a corresponding code fix. A pattern such as
1147        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1148        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1149        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1150        same bug. Such groups have to be quantified to be useful, or contained
1151        inside another quantified group. (If there's no repetition, the reference
1152        can never match.) The problem arises because, having left the group and
1153        moved on to the rest of the pattern, a later failure that backtracks into
1154        the group uses the captured value from the final iteration of the group
1155        rather than the correct earlier one. I have fixed this in PCRE by forcing
1156        any group that contains a reference to itself to be an atomic group; that
1157        is, there cannot be any backtracking into it once it has completed. This is
1158        similar to recursive and subroutine calls.
1159    
1160    
1161    Version 8.00 19-Oct-09
1162  ----------------------  ----------------------
1163    
1164    1.  The table for translating pcre_compile() error codes into POSIX error codes
1165        was out-of-date, and there was no check on the pcre_compile() error code
1166        being within the table. This could lead to an OK return being given in
1167        error.
1168    
1169    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1170        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1171        in a Windows environment.
1172    
1173    3.  The pcregrep --count option prints the count for each file even when it is
1174        zero, as does GNU grep. However, pcregrep was also printing all files when
1175        --files-with-matches was added. Now, when both options are given, it prints
1176        counts only for those files that have at least one match. (GNU grep just
1177        prints the file name in this circumstance, but including the count seems
1178        more useful - otherwise, why use --count?) Also ensured that the
1179        combination -clh just lists non-zero counts, with no names.
1180    
1181    4.  The long form of the pcregrep -F option was incorrectly implemented as
1182        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1183        but it seems right to fix it, and I didn't think it was worth preserving
1184        the old behaviour.
1185    
1186    5.  The command line items --regex=pattern and --regexp=pattern were not
1187        recognized by pcregrep, which required --regex pattern or --regexp pattern
1188        (with a space rather than an '='). The man page documented the '=' forms,
1189        which are compatible with GNU grep; these now work.
1190    
1191    6.  No libpcreposix.pc file was created for pkg-config; there was just
1192        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1193    
1194    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1195        when UCP support is not needed, by modifying the Python script that
1196        generates it from Unicode data files. This should not matter if the module
1197        is correctly used as a library, but I received one complaint about 50K of
1198        unwanted data. My guess is that the person linked everything into his
1199        program rather than using a library. Anyway, it does no harm.
1200    
1201    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1202        was a minimum greater than 1 for a wide character in a possessive
1203        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1204        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1205        character. Chaos in the form of incorrect output or a compiling loop could
1206        result.
1207    
1208    9.  The restrictions on what a pattern can contain when partial matching is
1209        requested for pcre_exec() have been removed. All patterns can now be
1210        partially matched by this function. In addition, if there are at least two
1211        slots in the offset vector, the offset of the earliest inspected character
1212        for the match and the offset of the end of the subject are set in them when
1213        PCRE_ERROR_PARTIAL is returned.
1214    
1215    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1216        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1217        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1218        and may be more useful for multi-segment matching.
1219    
1220    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1221        used to be given if ever the end of the subject was reached; now it is
1222        given only if matching could not proceed because another character was
1223        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1224        string "Z", which now yields "no match" instead of "partial match". In the
1225        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1226        final character ended with (*FAIL).
1227    
1228    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1229        if the pattern had a "must contain" character that was already found in the
1230        earlier partial match, unless partial matching was again requested. For
1231        example, with the pattern /dog.(body)?/, the "must contain" character is
1232        "g". If the first part-match was for the string "dog", restarting with
1233        "sbody" failed. This bug has been fixed.
1234    
1235    13. The string returned by pcre_dfa_exec() after a partial match has been
1236        changed so that it starts at the first inspected character rather than the
1237        first character of the match. This makes a difference only if the pattern
1238        starts with a lookbehind assertion or \b or \B (\K is not supported by
1239        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1240        matching functions compatible, and I think it's the right thing to do.
1241    
1242    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1243        so that the demonstration program is easily available in environments where
1244        PCRE has not been installed from source.
1245    
1246    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1247        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1248        library.
1249    
1250    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1251        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1252        is not the first non-POSIX option to be added. Clearly some people find
1253        these options useful.
1254    
1255    17. If a caller to the POSIX matching function regexec() passes a non-zero
1256        value for nmatch with a NULL value for pmatch, the value of
1257        nmatch is forced to zero.
1258    
1259    18. RunGrepTest did not have a test for the availability of the -u option of
1260        the diff command, as RunTest does. It now checks in the same way as
1261        RunTest, and also checks for the -b option.
1262    
1263    19. If an odd number of negated classes containing just a single character
1264        interposed, within parentheses, between a forward reference to a named
1265        subpattern and the definition of the subpattern, compilation crashed with
1266        an internal error, complaining that it could not find the referenced
1267        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1268        [The bug was that it was starting one character too far in when skipping
1269        over the character class, thus treating the ] as data rather than
1270        terminating the class. This meant it could skip too much.]
1271    
1272    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1273        /g option in pcretest when the pattern contains \K, which makes it possible
1274        to have an empty string match not at the start, even when the pattern is
1275        anchored. Updated pcretest and pcredemo to use this option.
1276    
1277    21. If the maximum number of capturing subpatterns in a recursion was greater
1278        than the maximum at the outer level, the higher number was returned, but
1279        with unset values at the outer level. The correct (outer level) value is
1280        now given.
1281    
1282    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1283        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1284        make it do so. The string so far is captured, making this feature
1285        compatible with Perl.
1286    
1287    23. The tests have been re-organized, adding tests 11 and 12, to make it
1288        possible to check the Perl 5.10 features against Perl 5.10.
1289    
1290    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1291        pattern matches a fixed length string. PCRE did not allow this; now it
1292        does. Neither allows recursion.
1293    
1294    25. I finally figured out how to implement a request to provide the minimum
1295        length of subject string that was needed in order to match a given pattern.
1296        (It was back references and recursion that I had previously got hung up
1297        on.) This code has now been added to pcre_study(); it finds a lower bound
1298        to the length of subject needed. It is not necessarily the greatest lower
1299        bound, but using it to avoid searching strings that are too short does give
1300        some useful speed-ups. The value is available to calling programs via
1301        pcre_fullinfo().
1302    
1303    26. While implementing 25, I discovered to my embarrassment that pcretest had
1304        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1305        study optimizations had never been tested with that matching function.
1306        Oops. What is worse, even when it was passed study data, there was a bug in
1307        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1308        were also very few tests of studied patterns with pcre_dfa_exec().
1309    
1310    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1311        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1312        on the other side of the coin, they are no longer allowed to have different
1313        names, because these cannot be distinguished in PCRE, and this has caused
1314        confusion. (This is a difference from Perl.)
1315    
1316    28. When duplicate subpattern names are present (necessarily with different
1317        numbers, as required by 27 above), and a test is made by name in a
1318        conditional pattern, either for a subpattern having been matched, or for
1319        recursion in such a pattern, all the associated numbered subpatterns are
1320        tested, and the overall condition is true if the condition is true for any
1321        one of them. This is the way Perl works, and is also more like the way
1322        testing by number works.
1323    
1324    
1325    Version 7.9 11-Apr-09
1326    ---------------------
1327    
1328    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1329        (pcretest), all targets were linked against these libraries. This included
1330        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1331        libraries. This caused unwanted dependencies to be created. This problem
1332        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1333        pcretest is linked with readline.
1334    
1335    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1336        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1337        moved outside it again, because FALSE and TRUE are already defined in AIX,
1338        but BOOL is not.
1339    
1340    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1341        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1342    
1343    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1344        hyphens) following file names and line numbers when outputting matching
1345        lines. This is not true; no spaces are inserted. I have also clarified the
1346        wording for the --colour (or --color) option.
1347    
1348    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1349        was not coloured; this is different to GNU grep, so I have changed it to be
1350        the same.
1351    
1352    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1353        each matching line was coloured. Now it goes on to look for further matches
1354        of any of the test patterns, which is the same behaviour as GNU grep.
1355    
1356    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1357        doesn't make sense to accept an empty string match in pcregrep, so I have
1358        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1359        seems to be how GNU grep behaves.
1360    
1361    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1362        start or after a newline", because the conditional assertion was not being
1363        correctly handled. The rule now is that both the assertion and what follows
1364        in the first alternative must satisfy the test.
1365    
1366    9.  If auto-callout was enabled in a pattern with a conditional group whose
1367        condition was an assertion, PCRE could crash during matching, both with
1368        pcre_exec() and pcre_dfa_exec().
1369    
1370    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1371        used for matching.
1372    
1373    11. Unicode property support in character classes was not working for
1374        characters (bytes) greater than 127 when not in UTF-8 mode.
1375    
1376    12. Added the -M command line option to pcretest.
1377    
1378    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1379    
1380    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1381    
1382    16. Added comments and documentation about mis-use of no_arg in the C++
1383        wrapper.
1384    
1385    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1386        from Martin Jerabek that uses macro names for all relevant character and
1387        string constants.
1388    
1389    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1390        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1391        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1392        these, but not everybody uses configure.
1393    
1394    19. A conditional group that had only one branch was not being correctly
1395        recognized as an item that could match an empty string. This meant that an
1396        enclosing group might also not be so recognized, causing infinite looping
1397        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1398        with the subject "ab", where knowledge that the repeated group can match
1399        nothing is needed in order to break the loop.
1400    
1401    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1402        exec(), but without supplying a callout function, matching went wrong.
1403    
1404    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1405        leak if the size of the offset vector was greater than 30. When the vector
1406        is smaller, the saved offsets during recursion go onto a local stack
1407        vector, but for larger vectors malloc() is used. It was failing to free
1408        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1409        error, in fact).
1410    
1411    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1412        heapframe that is used only when UTF-8 support is enabled. This caused no
1413        problem, but was untidy.
1414    
1415    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1416        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1417        included within another project.
1418    
1419    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1420        slightly modified by me:
1421    
1422          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1423              not building pcregrep.
1424    
1425          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1426              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1427    
1428    25. Forward references, both numeric and by name, in patterns that made use of
1429        duplicate group numbers, could behave incorrectly or give incorrect errors,
1430        because when scanning forward to find the reference group, PCRE was not
1431        taking into account the duplicate group numbers. A pattern such as
1432        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1433    
1434    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1435        the feature of a custom pointer more persuasive (as requested by a user).
1436    
1437    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1438        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1439        pre-defined.
1440    
1441    28. Added support for (*UTF8) at the start of a pattern.
1442    
1443    29. Arrange for flags added by the "release type" setting in CMake to be shown
1444        in the configuration summary.
1445    
1446    
1447    Version 7.8 05-Sep-08
1448    ---------------------
1449    
1450    1.  Replaced UCP searching code with optimized version as implemented for Ad
1451        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1452        stage table and inline lookup instead of a function, giving speed ups of 2
1453        to 5 times on some simple patterns that I tested. Permission was given to
1454        distribute the MultiStage2.py script that generates the tables (it's not in
1455        the tarball, but is in the Subversion repository).
1456    
1457    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1458        scripts.
1459    
1460    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1461        a group with a zero qualifier. The result of the study could be incorrect,
1462        or the function might crash, depending on the pattern.
1463    
1464    4.  Caseless matching was not working for non-ASCII characters in back
1465        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1466        It now works when Unicode Property Support is available.
1467    
1468    5.  In pcretest, an escape such as \x{de} in the data was always generating
1469        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1470        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1471        truncation.
1472    
1473    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1474    
1475    7.  Added two (int) casts to pcregrep when printing the difference of two
1476        pointers, in case they are 64-bit values.
1477    
1478    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1479        test 2 if it fails.
1480    
1481    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1482        and a #define of that name to empty if it is not externally set. This is to
1483        allow users of MSVC to set it if necessary.
1484    
1485    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1486        the convenience functions in the pcre_get.c source file.
1487    
1488    11. An option change at the start of a pattern that had top-level alternatives
1489        could cause overwriting and/or a crash. This command provoked a crash in
1490        some environments:
1491    
1492          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1493    
1494        This potential security problem was recorded as CVE-2008-2371.
1495    
1496    12. For a pattern where the match had to start at the beginning or immediately
1497        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1498        pcre_dfa_exec() could read past the end of the passed subject if there was
1499        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1500        pcretest so that it places the subject at the end of its malloc-ed buffer.
1501    
1502    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1503        exec() might read past the end of the data buffer in UTF-8 mode.
1504    
1505    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1506        the data contained the byte 0x85 as part of a UTF-8 character within its
1507        first line. This applied both to normal and DFA matching.
1508    
1509    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1510        /^[^d]*?$/8 failed to match "abc".
1511    
1512    16. Added a missing copyright notice to pcrecpp_internal.h.
1513    
1514    17. Make it more clear in the documentation that values returned from
1515        pcre_exec() in ovector are byte offsets, not character counts.
1516    
1517    18. Tidied a few places to stop certain compilers from issuing warnings.
1518    
1519    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1520        supplied by Stefan Weber. I made a further small update for 7.8 because
1521        there is a change of source arrangements: the pcre_searchfuncs.c module is
1522        replaced by pcre_ucd.c.
1523    
1524    
1525    Version 7.7 07-May-08
1526    ---------------------
1527    
1528    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1529        a string to a long long, pretend we don't even have a long long." This is
1530        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1531    
1532    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1533        pre-7.6 versions, which defined a global no_arg variable instead of putting
1534        it in the RE class. (See also #8 below.)
1535    
1536    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1537        Lopes.
1538    
1539    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1540    
1541        (1) The include/exclude patterns were being applied to the whole pathnames
1542            of files, instead of just to the final components.
1543    
1544        (2) If there was more than one level of directory, the subdirectories were
1545            skipped unless they satisfied the include/exclude conditions. This is
1546            inconsistent with GNU grep (and could even be seen as contrary to the
1547            pcregrep specification - which I improved to make it absolutely clear).
1548            The action now is always to scan all levels of directory, and just
1549            apply the include/exclude patterns to regular files.
1550    
1551    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1552        --exclude_dir in the tests to avoid scanning .svn directories.
1553    
1554    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1555        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1556        doesn't support NULs in patterns.
1557    
1558    7.  Added some missing "const"s to declarations of static tables in
1559        pcre_compile.c and pcre_dfa_exec.c.
1560    
1561    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1562        caused by fix #2  above. (Subsequently also a second patch to fix the
1563        first patch. And a third patch - this was a messy problem.)
1564    
1565    9.  Applied Craig's patch to remove the use of push_back().
1566    
1567    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1568        matching function regexec().
1569    
1570    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1571        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1572        references. PCRE supports relative numbers with this syntax (I don't think
1573        Oniguruma does).
1574    
1575    12. Previously, a group with a zero repeat such as (...){0} was completely
1576        omitted from the compiled regex. However, this means that if the group
1577        was called as a subroutine from elsewhere in the pattern, things went wrong
1578        (an internal error was given). Such groups are now left in the compiled
1579        pattern, with a new opcode that causes them to be skipped at execution
1580        time.
1581    
1582    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1583        to the way PCRE behaves:
1584    
1585        (a) A lone ] character is dis-allowed (Perl treats it as data).
1586    
1587        (b) A back reference to an unmatched subpattern matches an empty string
1588            (Perl fails the current match path).
1589    
1590        (c) A data ] in a character class must be notated as \] because if the
1591            first data character in a class is ], it defines an empty class. (In
1592            Perl it is not possible to have an empty class.) The empty class []
1593            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1594            The negative empty class [^] matches any one character, independently
1595            of the DOTALL setting.
1596    
1597    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1598        non-existent subpattern following a character class starting with ']' and
1599        containing () gave an internal compiling error instead of "reference to
1600        non-existent subpattern". Fortunately, when the pattern did exist, the
1601        compiled code was correct. (When scanning forwards to check for the
1602        existencd of the subpattern, it was treating the data ']' as terminating
1603        the class, so got the count wrong. When actually compiling, the reference
1604        was subsequently set up correctly.)
1605    
1606    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1607        it was being rejected as not supported by pcre_dfa_exec(), even though
1608        other assertions are supported. I have made pcre_dfa_exec() support
1609        (*FAIL).
1610    
1611    16. The implementation of 13c above involved the invention of a new opcode,
1612        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1613        cannot be changed at match time, I realized I could make a small
1614        improvement to matching performance by compiling OP_ALLANY instead of
1615        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1616        on the OP_ANY path.
1617    
1618    17. Compiling pcretest on Windows with readline support failed without the
1619        following two fixes: (1) Make the unistd.h include conditional on
1620        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1621    
1622    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1623        ncurses library to be included for pcretest when ReadLine support is
1624        requested, but also to allow for it to be overridden. This patch came from
1625        Daniel Bergström.
1626    
1627    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1628        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1629        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1630        spotting this.
1631    
1632    
1633    Version 7.6 28-Jan-08
1634    ---------------------
1635    
1636    1.  A character class containing a very large number of characters with
1637        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1638        overflow.
1639    
1640    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1641        HAVE_LONG_LONG is not defined.
1642    
1643    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1644        bring them up to date and include new features. This patch includes:
1645    
1646        - Fixed PH's badly added libz and libbz2 support.
1647        - Fixed a problem with static linking.
1648        - Added pcredemo. [But later removed - see 7 below.]
1649        - Fixed dftables problem and added an option.
1650        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1651            HAVE_LONG_LONG.
1652        - Added readline support for pcretest.
1653        - Added an listing of the option settings after cmake has run.
1654    
1655    4.  A user submitted a patch to Makefile that makes it easy to create
1656        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1657        Makefile.am that cause it to include this special target, without
1658        affecting anything else. Note that the same mingw target plus all
1659        the other distribution libraries and programs are now supported
1660        when configuring with CMake (see 6 below) instead of with
1661        Configure/Make.
1662    
1663    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1664        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1665        exported in the Windows port". It has not yet been confirmed that the patch
1666        solves the problem, but it does no harm.
1667    
1668    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1669        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1670        with CMake, and also correct the comment about stack recursion.
1671    
1672    7.  Remove the automatic building of pcredemo from the ./configure system and
1673        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1674        of a program that users should build themselves after PCRE is installed, so
1675        building it automatically is not really right. What is more, it gave
1676        trouble in some build environments.
1677    
1678    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1679    
1680    
1681    Version 7.5 10-Jan-08
1682    ---------------------
1683    
1684    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1685        values in parens when parsing an RE using the C++ wrapper."
1686    
1687    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1688        Characters greater than 255 were excluded from the class instead of being
1689        included.
1690    
1691    3.  The same bug as (2) above applied to negated POSIX classes such as
1692        [:^space:].
1693    
1694    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1695        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1696        I have changed it.
1697    
1698    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1699        first named subpattern) and a construct such as (?&a) would reference the
1700        first named subpattern whose name started with "a" (in other words, the
1701        length check was missing). Both these problems are fixed. "Subpattern name
1702        expected" is now given for (?&) (a zero-length name), and this patch also
1703        makes it give the same error for \k'' (previously it complained that that
1704        was a reference to a non-existent subpattern).
1705    
1706    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1707        this is right because (?- can be followed by option settings as well as by
1708        digits. I have, however, made the messages clearer.
1709    
1710    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1711        than the number used in the conditional) now cause a compile-time error.
1712        This is actually not compatible with Perl, which accepts such patterns, but
1713        treats the conditional as always being FALSE (as PCRE used to), but it
1714        seems to me that giving a diagnostic is better.
1715    
1716    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1717        and messages.
1718    
1719    9.  Fix two occurrences of "backslash" in comments that should have been
1720        "backspace".
1721    
1722    10. Remove two redundant lines of code that can never be obeyed (their function
1723        was moved elsewhere).
1724    
1725    11. The program that makes PCRE's Unicode character property table had a bug
1726        which caused it to generate incorrect table entries for sequences of
1727        characters that have the same character type, but are in different scripts.
1728        It amalgamated them into a single range, with the script of the first of
1729        them. In other words, some characters were in the wrong script. There were
1730        thirteen such cases, affecting characters in the following ranges:
1731    
1732          U+002b0 - U+002c1
1733          U+0060c - U+0060d
1734          U+0061e - U+00612
1735          U+0064b - U+0065e
1736          U+0074d - U+0076d
1737          U+01800 - U+01805
1738          U+01d00 - U+01d77
1739          U+01d9b - U+01dbf
1740          U+0200b - U+0200f
1741          U+030fc - U+030fe
1742          U+03260 - U+0327f
1743          U+0fb46 - U+0fbb1
1744          U+10450 - U+1049d
1745    
1746    12. The -o option (show only the matching part of a line) for pcregrep was not
1747        compatible with GNU grep in that, if there was more than one match in a
1748        line, it showed only the first of them. It now behaves in the same way as
1749        GNU grep.
1750    
1751    13. If the -o and -v options were combined for pcregrep, it printed a blank
1752        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1753        does the same. The return code can be used to tell if there were any
1754        non-matching lines.
1755    
1756    14. Added --file-offsets and --line-offsets to pcregrep.
1757    
1758    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1759        infinitely looping recursion. The bug was that positive lookaheads were not
1760        being skipped when checking for a possible empty match (negative lookaheads
1761        and both kinds of lookbehind were skipped).
1762    
1763    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1764        inclusion of <windows.h> to before rather than after the definition of
1765        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1766    
1767    17. Specifying a possessive quantifier with a specific limit for a Unicode
1768        character property caused pcre_compile() to compile bad code, which led at
1769        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1770        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1771        caused the error; without that there was no problem.
1772    
1773    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1774    
1775    19. Added --enable-pcretest-libreadline.
1776    
1777    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1778        RE::GlobalReplace(). As a result, the number of replacements returned was
1779        double what it should be. I removed one of the increments, but Craig sent a
1780        later patch that removed the other one (the right fix) and added unit tests
1781        that check the return values (which was not done before).
1782    
1783    21. Several CMake things:
1784    
1785        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1786            the names libpcre and libpcreposix, not just pcre and pcreposix.
1787    
1788        (2) The above change means that pcretest and pcregrep are now correctly
1789            linked with the newly-built libraries, not previously installed ones.
1790    
1791        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1792    
1793    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1794        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1795        UTF-8 newline character). The key issue is that the pattern starts .*;
1796        this means that the match must be either at the beginning, or after a
1797        newline. The bug was in the code for advancing after a failed match and
1798        checking that the new position followed a newline. It was not taking
1799        account of UTF-8 characters correctly.
1800    
1801    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1802        character classes. PCRE was not treating the sequence [:...:] as a
1803        character class unless the ... were all letters. Perl, however, seems to
1804        allow any characters between [: and :], though of course it rejects as
1805        unknown any "names" that contain non-letters, because all the known class
1806        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1807        for example, whereas PCRE did not - it did not recognize a POSIX character
1808        class. This seemed a bit dangerous, so the code has been changed to be
1809        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1810        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1811        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1812        Perl does, and where it didn't before.
1813    
1814    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1815        Windows environments %n is disabled by default.
1816    
1817    
1818    Version 7.4 21-Sep-07
1819    ---------------------
1820    
1821    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1822        means that a class such as [\s] counted as "explicit reference to CR or
1823        LF". That isn't really right - the whole point of the change was to try to
1824        help when there was an actual mention of one of the two characters. So now
1825        the change happens only if \r or \n (or a literal CR or LF) character is
1826        encountered.
1827    
1828    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1829        of both had grown to the point where there were only 3 bits left.
1830        Fortunately, there was spare space in the data structure, and so I have
1831        moved the internal flags into a new 16-bit field to free up more option
1832        bits.
1833    
1834    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1835        but did not set the internal JCHANGED flag - either of these is enough to
1836        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1837        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1838        start sets both bits.
1839    
1840    4.  Added options (at build time, compile time, exec time) to change \R from
1841        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1842    
1843    5.  doc/pcresyntax.html was missing from the distribution.
1844    
1845    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1846        compatibility, even though it is no longer used.
1847    
1848    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1849        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1850        windows.h file is present (where different names are used). [This was
1851        reversed later after testing - see 16 below.]
1852    
1853    8.  Changed all #include <config.h> to #include "config.h". There were also
1854        some further <pcre.h> cases that I changed to "pcre.h".
1855    
1856    9.  When pcregrep was used with the --colour option, it missed the line ending
1857        sequence off the lines that it output.
1858    
1859    10. It was pointed out to me that arrays of string pointers cause lots of
1860        relocations when a shared library is dynamically loaded. A technique of
1861        using a single long string with a table of offsets can drastically reduce
1862        these. I have refactored PCRE in four places to do this. The result is
1863        dramatic:
1864    
1865          Originally:                          290
1866          After changing UCP table:            187
1867          After changing error message table:   43
1868          After changing table of "verbs"       36
1869          After changing table of Posix names   22
1870    
1871        Thanks to the folks working on Gregex for glib for this insight.
1872    
1873    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1874        unicode-properties was also set.
1875    
1876    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1877    
1878    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1879        checked only for CRLF.
1880    
1881    14. Added casts to pcretest.c to avoid compiler warnings.
1882    
1883    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1884    
1885    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1886        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1887        entirely. This removes changes made in 7 above.
1888    
1889    17. The CMake files have been updated, and there is now more information about
1890        building with CMake in the NON-UNIX-USE document.
1891    
1892    
1893    Version 7.3 28-Aug-07
1894    ---------------------
1895    
1896     1. In the rejigging of the build system that eventually resulted in 7.1, the
1897        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1898        brackets there is not right, since it causes compilers to look for an
1899        installed pcre.h, not the version that is in the source that is being
1900        compiled (which of course may be different). I have changed it back to:
1901    
1902          #include "pcre.h"
1903    
1904        I have a vague recollection that the change was concerned with compiling in
1905        different directories, but in the new build system, that is taken care of
1906        by the VPATH setting the Makefile.
1907    
1908     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1909        when the subject happened to end in the byte 0x85 (e.g. if the last
1910        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1911        characters but of course it shouldn't be taken as a newline when it is part
1912        of another character. The bug was that, for an unlimited repeat of . in
1913        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1914        characters when looking for a newline.
1915    
1916     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1917    
1918     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1919        in debug output.
1920    
1921     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1922        long printing in the pcrecpp unittest when running under MinGW.
1923    
1924     6. ESC_K was left out of the EBCDIC table.
1925    
1926     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1927        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1928        limit also applies to "virtual nesting" when a pattern is recursive, and in
1929        this case 1000 isn't so big. I have been able to remove this limit at the
1930        expense of backing off one optimization in certain circumstances. Normally,
1931        when pcre_exec() would call its internal match() function recursively and
1932        immediately return the result unconditionally, it uses a "tail recursion"
1933        feature to save stack. However, when a subpattern that can match an empty
1934        string has an unlimited repetition quantifier, it no longer makes this
1935        optimization. That gives it a stack frame in which to save the data for
1936        checking that an empty string has been matched. Previously this was taken
1937        from the 1000-entry workspace that had been reserved. So now there is no
1938        explicit limit, but more stack is used.
1939    
1940     8. Applied Daniel's patches to solve problems with the import/export magic
1941        syntax that is required for Windows, and which was going wrong for the
1942        pcreposix and pcrecpp parts of the library. These were overlooked when this
1943        problem was solved for the main library.
1944    
1945     9. There were some crude static tests to avoid integer overflow when computing
1946        the size of patterns that contain repeated groups with explicit upper
1947        limits. As the maximum quantifier is 65535, the maximum group length was
1948        set at 30,000 so that the product of these two numbers did not overflow a
1949        32-bit integer. However, it turns out that people want to use groups that
1950        are longer than 30,000 bytes (though not repeat them that many times).
1951        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1952        made it possible to implement the integer overflow checks in a much more
1953        dynamic way, which I have now done. The artificial limitation on group
1954        length has been removed - we now have only the limit on the total length of
1955        the compiled pattern, which depends on the LINK_SIZE setting.
1956    
1957    10. Fixed a bug in the documentation for get/copy named substring when
1958        duplicate names are permitted. If none of the named substrings are set, the
1959        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1960        empty string.
1961    
1962    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1963        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1964        because the ] is interpreted as the first data character and the
1965        terminating ] is not found. PCRE has been made compatible with Perl in this
1966        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1967        cause memory overwriting.
1968    
1969    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1970        string has been matched (to stop an infinite loop). It was not recognizing
1971        a conditional subpattern that could match an empty string if that
1972        subpattern was within another subpattern. For example, it looped when
1973        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1974        condition was not nested. This bug has been fixed.
1975    
1976    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1977        past the start of the subject in the presence of bytes with the top bit
1978        set, for example "\x8aBCD".
1979    
1980    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1981        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1982    
1983    14. Optimized (?!) to (*FAIL).
1984    
1985    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1986        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1987        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1988        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1989        does: it's just the validity check that is more restrictive.
1990    
1991    16. Inserted checks for integer overflows during escape sequence (backslash)
1992        processing, and also fixed erroneous offset values for syntax errors during
1993        backslash processing.
1994    
1995    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1996        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1997    
1998    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1999        caused an overrun.
2000    
2001    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2002        something other than just ASCII characters) inside a group that had an
2003        unlimited repeat caused a loop at compile time (while checking to see
2004        whether the group could match an empty string).
2005    
2006    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2007        [\P{Any}] did so. (Error in the code for printing property names.)
2008    
2009    21. An orphan \E inside a character class could cause a crash.
2010    
2011    22. A repeated capturing bracket such as (A)? could cause a wild memory
2012        reference during compilation.
2013    
2014    23. There are several functions in pcre_compile() that scan along a compiled
2015        expression for various reasons (e.g. to see if it's fixed length for look
2016        behind). There were bugs in these functions when a repeated \p or \P was
2017        present in the pattern. These operators have additional parameters compared
2018        with \d, etc, and these were not being taken into account when moving along
2019        the compiled data. Specifically:
2020    
2021        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2022            length.
2023    
2024        (b) An item such as \pL+ within a repeated group could cause crashes or
2025            loops.
2026    
2027        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2028            "reference to non-existent subpattern" error.
2029    
2030        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2031    
2032    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2033        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2034    
2035    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2036    
2037    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2038        character were causing crashes (broken optimization).
2039    
2040    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2041        \p or \P) caused a compile-time loop.
2042    
2043    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2044        break. For example, the unstudied pattern [\r\n]A does not match the string
2045        "\r\nA" because change 7.0/46 below moves the current point on by two
2046        characters after failing to match at the start. However, the pattern \nA
2047        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2048        the same is true. There doesn't seem any very clean way out of this, but
2049        what I have chosen to do makes the common cases work: PCRE now takes note
2050        of whether there can be an explicit match for \r or \n anywhere in the
2051        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2052        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2053        pattern has explicit CR or LF references.
2054    
2055    29. Added (*CR) etc for changing newline setting at start of pattern.
2056    
2057    
2058    Version 7.2 19-Jun-07
2059    ---------------------
2060    
2061     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2062        which is apparently normally available under Windows.
2063    
2064     2. Re-jig the pcregrep tests with different newline settings in an attempt
2065        to make them independent of the local environment's newline setting.
2066    
2067     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2068    
2069     4. Some of the "internals" tests were previously cut out when the link size
2070        was not 2, because the output contained actual offsets. The recent new
2071        "Z" feature of pcretest means that these can be cut out, making the tests
2072        usable with all link sizes.
2073    
2074     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2075        stack recursion. This gives a massive performance boost under BSD, but just
2076        a small improvement under Linux. However, it saves one field in the frame
2077        in all cases.
2078    
2079     6. Added more features from the forthcoming Perl 5.10:
2080    
2081        (a) (?-n) (where n is a string of digits) is a relative subroutine or
2082            recursion call. It refers to the nth most recently opened parentheses.
2083    
2084        (b) (?+n) is also a relative subroutine call; it refers to the nth next
2085            to be opened parentheses.
2086    
2087        (c) Conditions that refer to capturing parentheses can be specified
2088            relatively, for example, (?(-2)... or (?(+3)...
2089    
2090        (d) \K resets the start of the current match so that everything before
2091            is not part of it.
2092    
2093        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2094    
2095        (f) \g{name} is another synonym - part of Perl 5.10's unification of
2096            reference syntax.
2097    
2098        (g) (?| introduces a group in which the numbering of parentheses in each
2099            alternative starts with the same number.
2100    
2101        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2102    
2103     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2104        PCRE_INFO_JCHANGED.
2105    
2106     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
2107        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2108        for detecting groups that can match an empty string.
2109    
2110     9. A pattern with a very large number of alternatives (more than several
2111        hundred) was running out of internal workspace during the pre-compile
2112        phase, where pcre_compile() figures out how much memory will be needed. A
2113        bit of new cunning has reduced the workspace needed for groups with
2114        alternatives. The 1000-alternative test pattern now uses 12 bytes of
2115        workspace instead of running out of the 4096 that are available.
2116    
2117    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2118    
2119    11. Applied patch from Google to remove an optimization that didn't quite work.
2120        The report of the bug said:
2121    
2122          pcrecpp::RE("a*").FullMatch("aaa") matches, while
2123          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2124          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2125    
2126    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2127        it matched the wrong number of bytes.
2128    
2129    
2130    Version 7.1 24-Apr-07
2131    ---------------------
2132    
2133     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2134        that is more "standard", making use of automake and other Autotools. There
2135        is some re-arrangement of the files and adjustment of comments consequent
2136        on this.
2137    
2138     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2139        for recursive directory scanning broke on some systems because the files
2140        are not scanned in any specific order and on different systems the order
2141        was different. A call to "sort" has been inserted into RunGrepTest for the
2142        approprate test as a short-term fix. In the longer term there may be an
2143        alternative.
2144    
2145     3. I had an email from Eric Raymond about problems translating some of PCRE's
2146        man pages to HTML (despite the fact that I distribute HTML pages, some
2147        people do their own conversions for various reasons). The problems
2148        concerned the use of low-level troff macros .br and .in. I have therefore
2149        removed all such uses from the man pages (some were redundant, some could
2150        be replaced by .nf/.fi pairs). The 132html script that I use to generate
2151        HTML has been updated to handle .nf/.fi and to complain if it encounters
2152        .br or .in.
2153    
2154     4. Updated comments in configure.ac that get placed in config.h.in and also
2155        arranged for config.h to be included in the distribution, with the name
2156        config.h.generic, for the benefit of those who have to compile without
2157        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2158    
2159     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2160        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2161        makevp.bat for the current PCRE, using the additional files
2162        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2163    
2164     6. A Windows user reported a minor discrepancy with test 2, which turned out
2165        to be caused by a trailing space on an input line that had got lost in his
2166        copy. The trailing space was an accident, so I've just removed it.
2167    
2168     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2169        that is needed.
2170    
2171     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2172        as "const" (a) because they are and (b) because it helps the PHP
2173        maintainers who have recently made a script to detect big data structures
2174        in the php code that should be moved to the .rodata section. I remembered
2175        to update Builducptable as well, so it won't revert if ucptable.h is ever
2176        re-created.
2177    
2178     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2179        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2180        order to be able to cut out the UTF-8 tables in the latter when UTF-8
2181        support is not required. This saves 1.5-2K of code, which is important in
2182        some applications.
2183    
2184        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2185        so as not to refer to the tables, even though these functions will never be
2186        called when UTF-8 support is disabled. Otherwise there are problems with a
2187        shared library.
2188    
2189    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2190    
2191        (a) It was defining its arguments as char * instead of void *.
2192    
2193        (b) It was assuming that all moves were upwards in memory; this was true
2194            a long time ago when I wrote it, but is no longer the case.
2195    
2196        The emulated memove() is provided for those environments that have neither
2197        memmove() nor bcopy(). I didn't think anyone used it these days, but that
2198        is clearly not the case, as these two bugs were recently reported.
2199    
2200    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2201        and Detrail to create the HTML documentation, the .txt form of the man
2202        pages, and it removes trailing spaces from listed files. It also creates
2203        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2204        case, it wraps all the #defines with #ifndefs. This script should be run
2205        before "make dist".
2206    
2207    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2208        with Unicode property support.
2209    
2210        (a) For a maximizing quantifier, if the two different cases of the
2211            character were of different lengths in their UTF-8 codings (there are
2212            some cases like this - I found 11), and the matching function had to
2213            back up over a mixture of the two cases, it incorrectly assumed they
2214            were both the same length.
2215    
2216        (b) When PCRE was configured to use the heap rather than the stack for
2217            recursion during matching, it was not correctly preserving the data for
2218            the other case of a UTF-8 character when checking ahead for a match
2219            while processing a minimizing repeat. If the check also involved
2220            matching a wide character, but failed, corruption could cause an
2221            erroneous result when trying to check for a repeat of the original
2222            character.
2223    
2224    13. Some tidying changes to the testing mechanism:
2225    
2226        (a) The RunTest script now detects the internal link size and whether there
2227            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2228            values substituted by "configure". (The RunGrepTest script already did
2229            this for UTF-8.) The configure.ac script no longer substitutes the
2230            relevant variables.
2231    
2232        (b) The debugging options /B and /D in pcretest show the compiled bytecode
2233            with length and offset values. This means that the output is different
2234            for different internal link sizes. Test 2 is skipped for link sizes
2235            other than 2 because of this, bypassing the problem. Unfortunately,
2236            there was also a test in test 3 (the locale tests) that used /B and
2237            failed for link sizes other than 2. Rather than cut the whole test out,
2238            I have added a new /Z option to pcretest that replaces the length and
2239            offset values with spaces. This is now used to make test 3 independent
2240            of link size. (Test 2 will be tidied up later.)
2241    
2242    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2243        segmentation fault instead of returning the appropriate error message.
2244    
2245    15. In multiline mode when the newline sequence was set to "any", the pattern
2246        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2247        This doesn't seem right; it now treats the CRLF combination as the line
2248        ending, and so does not match in that case. It's only a pattern such as ^$
2249        that would hit this one: something like ^ABC$ would have failed after \r
2250        and then tried again after \r\n.
2251    
2252    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2253        in an attempt to make files that differ only in their line terminators
2254        compare equal. This works on Linux.
2255    
2256    17. Under certain error circumstances pcregrep might try to free random memory
2257        as it exited. This is now fixed, thanks to valgrind.
2258    
2259    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2260        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2261        was because its rules for how to advance for /g after matching an empty
2262        string at the end of a line did not allow for this case. They now check for
2263        it specially.
2264    
2265    20. pcretest is supposed to handle patterns and data of any length, by
2266        extending its buffers when necessary. It was getting this wrong when the
2267        buffer for a data line had to be extended.
2268    
2269    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2270        CRLF as a newline sequence.
2271    
2272    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2273        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2274        I have nevertheless tidied it up.
2275    
2276    23. Added some casts to kill warnings from HP-UX ia64 compiler.
2277    
2278    24. Added a man page for pcre-config.
2279    
2280    
2281    Version 7.0 19-Dec-06
2282    ---------------------
2283    
2284     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2285        moving to gcc 4.1.1.
2286    
2287     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2288        sys/time.h, which is documented as needed for this function. It doesn't
2289        seem to matter on Linux, but it showed up on some releases of OS X.
2290    
2291     3. It seems that there are systems where bytes whose values are greater than
2292        127 match isprint() in the "C" locale. The "C" locale should be the
2293        default when a C program starts up. In most systems, only ASCII printing
2294        characters match isprint(). This difference caused the output from pcretest
2295        to vary, making some of the tests fail. I have changed pcretest so that:
2296    
2297        (a) When it is outputting text in the compiled version of a pattern, bytes
2298            other than 32-126 are always shown as hex escapes.
2299    
2300        (b) When it is outputting text that is a matched part of a subject string,
2301            it does the same, unless a different locale has been set for the match
2302            (using the /L modifier). In this case, it uses isprint() to decide.
2303    
2304     4. Fixed a major bug that caused incorrect computation of the amount of memory
2305        required for a compiled pattern when options that changed within the
2306        pattern affected the logic of the preliminary scan that determines the
2307        length. The relevant options are -x, and -i in UTF-8 mode. The result was
2308        that the computed length was too small. The symptoms of this bug were
2309        either the PCRE error "internal error: code overflow" from pcre_compile(),
2310        or a glibc crash with a message such as "pcretest: free(): invalid next
2311        size (fast)". Examples of patterns that provoked this bug (shown in
2312        pcretest format) are:
2313    
2314          /(?-x: )/x
2315          /(?x)(?-x: \s*#\s*)/
2316          /((?i)[\x{c0}])/8
2317          /(?i:[\x{c0}])/8
2318    
2319        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2320        is now done differently.
2321    
2322     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2323        wrapper classes; (b) implement a new function in the C++ scanner that is
2324        more efficient than the old way of doing things because it avoids levels of
2325        recursion in the regex matching; (c) add a paragraph to the documentation
2326        for the FullMatch() function.
2327    
2328     6. The escape sequence \n was being treated as whatever was defined as
2329        "newline". Not only was this contrary to the documentation, which states
2330        that \n is character 10 (hex 0A), but it also went horribly wrong when
2331        "newline" was defined as CRLF. This has been fixed.
2332    
2333     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2334        was being set to -1 for the "end of line" case (supposedly a value that no
2335        character can have). Though this value is never used (the check for end of
2336        line is "zero bytes in current character"), it caused compiler complaints.
2337        I've changed it to 0xffffffff.
2338    
2339     8. In pcre_version.c, the version string was being built by a sequence of
2340        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2341        string (as it is for production releases) called a macro with an empty
2342        argument. The C standard says the result of this is undefined. The gcc
2343        compiler treats it as an empty string (which was what was wanted) but it is
2344        reported that Visual C gives an error. The source has been hacked around to
2345        avoid this problem.
2346    
2347     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2348        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2349        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2350        of them did).
2351    
2352    10. Originally, pcretest opened its input and output without "b"; then I was
2353        told that "b" was needed in some environments, so it was added for release
2354        5.0 to both the input and output. (It makes no difference on Unix-like
2355        systems.) Later I was told that it is wrong for the input on Windows. I've
2356        now abstracted the modes into two macros, to make it easier to fiddle with
2357        them, and removed "b" from the input mode under Windows.
2358    
2359    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2360    
2361    12. Added -help and --help to pcretest as an official way of being reminded
2362        of the options.
2363    
2364    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2365        and pcrecpp.cc because they annoy compilers at high warning levels.
2366    
2367    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2368    
2369    15. Fixed an occurrence of == in configure.ac that should have been = (shell
2370        scripts are not C programs :-) and which was not noticed because it works
2371        on Linux.
2372    
2373    16. pcretest is supposed to handle any length of pattern and data line (as one
2374        line or as a continued sequence of lines) by extending its input buffer if
2375        necessary. This feature was broken for very long pattern lines, leading to
2376        a string of junk being passed to pcre_compile() if the pattern was longer
2377        than about 50K.
2378    
2379    17. I have done a major re-factoring of the way pcre_compile() computes the
2380        amount of memory needed for a compiled pattern. Previously, there was code
2381        that made a preliminary scan of the pattern in order to do this. That was
2382        OK when PCRE was new, but as the facilities have expanded, it has become
2383        harder and harder to keep it in step with the real compile phase, and there
2384        have been a number of bugs (see for example, 4 above). I have now found a
2385        cunning way of running the real compile function in a "fake" mode that
2386        enables it to compute how much memory it would need, while actually only
2387        ever using a few hundred bytes of working memory and without too many
2388        tests of the mode. This should make future maintenance and development
2389        easier. A side effect of this work is that the limit of 200 on the nesting
2390        depth of parentheses has been removed (though this was never a serious
2391        limitation, I suspect). However, there is a downside: pcre_compile() now
2392        runs more slowly than before (30% or more, depending on the pattern). I
2393        hope this isn't a big issue. There is no effect on runtime performance.
2394    
2395    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2396        newline (only possible for the last line of a file) and it was a
2397        pattern that set a locale (followed by /Lsomething), pcretest crashed.
2398    
2399    19. Added additional timing features to pcretest. (1) The -tm option now times
2400        matching only, not compiling. (2) Both -t and -tm can be followed, as a
2401        separate command line item, by a number that specifies the number of
2402        repeats to use when timing. The default is 50000; this gives better
2403        precision, but takes uncomfortably long for very large patterns.
2404    
2405    20. Extended pcre_study() to be more clever in cases where a branch of a
2406        subpattern has no definite first character. For example, (a*|b*)[cd] would
2407        previously give no result from pcre_study(). Now it recognizes that the
2408        first character must be a, b, c, or d.
2409    
2410    21. There was an incorrect error "recursive call could loop indefinitely" if
2411        a subpattern (or the entire pattern) that was being tested for matching an
2412        empty string contained only one non-empty item after a nested subpattern.
2413        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2414        incorrectly, because the \d was being skipped in the check.
2415    
2416    22. The pcretest program now has a new pattern option /B and a command line
2417        option -b, which is equivalent to adding /B to every pattern. This causes
2418        it to show the compiled bytecode, without the additional information that
2419        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2420        is the same as /B/I).
2421    
2422    23. A new optimization is now able automatically to treat some sequences such
2423        as a*b as a*+b. More specifically, if something simple (such as a character
2424        or a simple class like \d) has an unlimited quantifier, and is followed by
2425        something that cannot possibly match the quantified thing, the quantifier
2426        is automatically "possessified".
2427    
2428    24. A recursive reference to a subpattern whose number was greater than 39
2429        went wrong under certain circumstances in UTF-8 mode. This bug could also
2430        have affected the operation of pcre_study().
2431    
2432    25. Realized that a little bit of performance could be had by replacing
2433        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2434    
2435    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2436    
2437    27. Possessive quantifiers such as a++ were previously implemented by turning
2438        them into atomic groups such as ($>a+). Now they have their own opcodes,
2439        which improves performance. This includes the automatically created ones
2440        from 23 above.
2441    
2442    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2443        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2444        the first matched character to be a colon. This applied both to named and
2445        numbered groups.
2446    
2447    29. The ucpinternal.h header file was missing its idempotency #ifdef.
2448    
2449    30. I was sent a "project" file called libpcre.a.dev which I understand makes
2450        building PCRE on Windows easier, so I have included it in the distribution.
2451    
2452    31. There is now a check in pcretest against a ridiculously large number being
2453        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2454        loop, the loop is abandoned.
2455    
2456    32. Forward references to subpatterns in conditions such as (?(2)...) where
2457        subpattern 2 is defined later cause pcre_compile() to search forwards in
2458        the pattern for the relevant set of parentheses. This search went wrong
2459        when there were unescaped parentheses in a character class, parentheses
2460        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2461    
2462    33. "Subroutine" calls and backreferences were previously restricted to
2463        referencing subpatterns earlier in the regex. This restriction has now
2464        been removed.
2465    
2466    34. Added a number of extra features that are going to be in Perl 5.10. On the
2467        whole, these are just syntactic alternatives for features that PCRE had
2468        previously implemented using the Python syntax or my own invention. The
2469        other formats are all retained for compatibility.
2470    
2471        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2472            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2473            also .NET compatible.
2474    
2475        (b) A recursion or subroutine call to a named group can now be defined as
2476            (?&name) as well as (?P>name).
2477    
2478        (c) A backreference to a named group can now be defined as \k<name> or
2479            \k'name' as well as (?P=name). The new forms, as well as being in Perl
2480            5.10, are also .NET compatible.
2481    
2482        (d) A conditional reference to a named group can now use the syntax
2483            (?(<name>) or (?('name') as well as (?(name).
2484    
2485        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2486            groups (named and numbered) that are never evaluated inline, but can be
2487            called as "subroutines" from elsewhere. In effect, the DEFINE condition
2488            is always false. There may be only one alternative in such a group.
2489    
2490        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2491            as the simple (?(R). The condition is true only if the most recent
2492            recursion is that of the given number or name. It does not search out
2493            through the entire recursion stack.
2494    
2495        (g) The escape \gN or \g{N} has been added, where N is a positive or
2496            negative number, specifying an absolute or relative reference.
2497    
2498    35. Tidied to get rid of some further signed/unsigned compiler warnings and
2499        some "unreachable code" warnings.
2500    
2501    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2502        things, this adds five new scripts.
2503    
2504    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2505        There were also incompatibilities regarding the handling of \Q..\E inside
2506        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2507        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2508    
2509    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2510        matches an empty string, and forcibly breaks the loop. There were bugs in
2511        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
2512        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
2513        separate and independent bugs (that affected different cases) have been
2514        fixed.
2515    
2516    39. Refactored the code to abolish the use of different opcodes for small
2517        capturing bracket numbers. This is a tidy that I avoided doing when I
2518        removed the limit on the number of capturing brackets for 3.5 back in 2001.
2519        The new approach is not only tidier, it makes it possible to reduce the
2520        memory needed to fix the previous bug (38).
2521    
2522    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2523        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2524        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2525        mode.
2526    
2527    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2528        report.
2529    
2530    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2531        copy construction and assignment in the C++ wrapper.
2532    
2533    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2534        couple of bugs that could have given wrong results in the "--newline=crlf"
2535        case.
2536    
2537    44. Added a number of casts and did some reorganization of signed/unsigned int
2538        variables following suggestions from Dair Grant. Also renamed the variable
2539        "this" as "item" because it is a C++ keyword.
2540    
2541    45. Arranged for dftables to add
2542    
2543          #include "pcre_internal.h"
2544    
2545        to pcre_chartables.c because without it, gcc 4.x may remove the array
2546        definition from the final binary if PCRE is built into a static library and
2547        dead code stripping is activated.
2548    
2549    46. For an unanchored pattern, if a match attempt fails at the start of a
2550        newline sequence, and the newline setting is CRLF or ANY, and the next two
2551        characters are CRLF, advance by two characters instead of one.
2552    
2553    
2554    Version 6.7 04-Jul-06
2555    ---------------------
2556    
2557     1. In order to handle tests when input lines are enormously long, pcretest has
2558        been re-factored so that it automatically extends its buffers when
2559        necessary. The code is crude, but this _is_ just a test program. The
2560        default size has been increased from 32K to 50K.
2561    
2562     2. The code in pcre_study() was using the value of the re argument before
2563        testing it for NULL. (Of course, in any sensible call of the function, it
2564        won't be NULL.)
2565    
2566     3. The memmove() emulation function in pcre_internal.h, which is used on
2567        systems that lack both memmove() and bcopy() - that is, hardly ever -
2568        was missing a "static" storage class specifier.
2569    
2570     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2571        containing an extended class (one that cannot be represented by a bitmap
2572        because it contains high-valued characters or Unicode property items, e.g.
2573        [\pZ]). Almost always one would set UTF-8 mode when processing such a
2574        pattern, but PCRE should not loop if you do not (it no longer does).
2575        [Detail: two cases were found: (a) a repeated subpattern containing an
2576        extended class; (b) a recursive reference to a subpattern that followed a
2577        previous extended class. It wasn't skipping over the extended class
2578        correctly when UTF-8 mode was not set.]
2579    
2580     5. A negated single-character class was not being recognized as fixed-length
2581        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2582        compile error "lookbehind assertion is not fixed length".
2583    
2584     6. The RunPerlTest auxiliary script was showing an unexpected difference
2585        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2586        write a Perl script that can interpret lines of an input file either as
2587        byte characters or as UTF-8, which is what "perltest" was being required to
2588        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2589        can't do is switch easily at run time between having the "use utf8;" pragma
2590        or not. In the end, I fudged it by using the RunPerlTest script to insert
2591        "use utf8;" explicitly for the UTF-8 tests.
2592    
2593     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2594        the end of the subject string, contrary to the documentation and to what
2595        Perl does. This was true of both matching functions. Now it matches only at
2596        the start of the subject and immediately after *internal* newlines.
2597    
2598     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2599        a pointer to an int instead of a pointer to an unsigned long int. This
2600        caused problems on 64-bit systems.
2601    
2602     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2603        instance of the 'standard' template library not being so standard".
2604    
2605    10. There was no check on the number of named subpatterns nor the maximum
2606        length of a subpattern name. The product of these values is used to compute
2607        the size of the memory block for a compiled pattern. By supplying a very
2608        long subpattern name and a large number of named subpatterns, the size
2609        computation could be caused to overflow. This is now prevented by limiting
2610        the length of names to 32 characters, and the number of named subpatterns
2611        to 10,000.
2612    
2613    11. Subpatterns that are repeated with specific counts have to be replicated in
2614        the compiled pattern. The size of memory for this was computed from the
2615        length of the subpattern and the repeat count. The latter is limited to
2616        65535, but there was no limit on the former, meaning that integer overflow
2617        could in principle occur. The compiled length of a repeated subpattern is
2618        now limited to 30,000 bytes in order to prevent this.
2619    
2620    12. Added the optional facility to have named substrings with the same name.
2621    
2622    13. Added the ability to use a named substring as a condition, using the
2623        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2624        are numbers (not recommended). Forward references are permitted.
2625    
2626    14. Added forward references in named backreferences (if you see what I mean).
2627    
2628    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2629        pattern could run off the end of the subject. For example, the pattern
2630        "(?s)(.{1,5})"8 did this with the subject "ab".
2631    
2632    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2633        PCRE_CASELESS was set when matching characters that were quantified with ?
2634        or *.
2635    
2636    17. A character class other than a single negated character that had a minimum
2637        but no maximum quantifier - for example [ab]{6,} - was not handled
2638        correctly by pce_dfa_exec(). It would match only one character.
2639    
2640    18. A valid (though odd) pattern that looked like a POSIX character
2641        class but used an invalid character after [ (for example [[,abc,]]) caused
2642        pcre_compile() to give the error "Failed: internal error: code overflow" or
2643        in some cases to crash with a glibc free() error. This could even happen if
2644        the pattern terminated after [[ but there just happened to be a sequence of
2645        letters, a binary zero, and a closing ] in the memory that followed.
2646    
2647    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2648        over the years. Originally (before any Unicode support), just the bottom 8
2649        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2650        output from "man perlunicode" includes this:
2651    
2652          The regular expression compiler produces polymorphic opcodes.  That
2653          is, the pattern adapts to the data and automatically switches to
2654          the Unicode character scheme when presented with Unicode data--or
2655          instead uses a traditional byte scheme when presented with byte
2656          data.
2657    
2658        Sadly, a wide octal escape does not cause a switch, and in a string with
2659        no other multibyte characters, these octal escapes are treated as before.
2660        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2661        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2662        Unicode string.
2663    
2664        I have not perpetrated such confusion in PCRE. Up till now, it took just
2665        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2666        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2667        translate to the appropriate multibyte character.
2668    
2669    29. Applied some refactoring to reduce the number of warnings from Microsoft
2670        and Borland compilers. This has included removing the fudge introduced
2671        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2672        a warning about an unused variable.
2673    
2674    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2675        characters since release 4.0, because Perl (from release 5.004) does not.
2676        [Or at least, is documented not to: some releases seem to be in conflict
2677        with the documentation.] However, when a pattern was studied with
2678        pcre_study() and all its branches started with \s, PCRE still included VT
2679        as a possible starting character. Of course, this did no harm; it just
2680        caused an unnecessary match attempt.
2681    
2682    22. Removed a now-redundant internal flag bit that recorded the fact that case
2683        dependency changed within the pattern. This was once needed for "required
2684        byte" processing, but is no longer used. This recovers a now-scarce options
2685        bit. Also moved the least significant internal flag bit to the most-
2686        significant bit of the word, which was not previously used (hangover from
2687        the days when it was an int rather than a uint) to free up another bit for
2688        the future.
2689    
2690    23. Added support for CRLF line endings as well as CR and LF. As well as the
2691        default being selectable at build time, it can now be changed at runtime
2692        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2693        specify that it is scanning data with non-default line endings.
2694    
2695    24. Changed the definition of CXXLINK to make it agree with the definition of
2696        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2697    
2698    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2699        recursions. This makes a big different to stack usage for some patterns.
2700    
2701    26. If a subpattern containing a named recursion or subroutine reference such
2702        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2703        the space required for the compiled pattern went wrong and gave too small a
2704        value. Depending on the environment, this could lead to "Failed: internal
2705        error: code overflow at offset 49" or "glibc detected double free or
2706        corruption" errors.
2707    
2708    27. Applied patches from Google (a) to support the new newline modes and (b) to
2709        advance over multibyte UTF-8 characters in GlobalReplace.
2710    
2711    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2712        difference for some implementation of PCRE in some Windows version.
2713    
2714    29. Added some extra testing facilities to pcretest:
2715    
2716        \q<number>   in a data line sets the "match limit" value
2717        \Q<number>   in a data line sets the "match recursion limt" value
2718        -S <number>  sets the stack size, where <number> is in megabytes
2719    
2720        The -S option isn't available for Windows.
2721    
2722    
2723    Version 6.6 06-Feb-06
2724    ---------------------
2725    
2726     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2727        in pcreposix.h. I have copied the definition from pcre.h.
2728    
2729     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2730        because pcre.h is no longer a built file.
2731    
2732     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2733        not normally included in the compiled code.
2734    
2735    
2736    Version 6.5 01-Feb-06
2737    ---------------------
2738    
2739     1. When using the partial match feature with pcre_dfa_exec(), it was not
2740        anchoring the second and subsequent partial matches at the new starting
2741        point. This could lead to incorrect results. For example, with the pattern
2742        /1234/, partially matching against "123" and then "a4" gave a match.
2743    
2744     2. Changes to pcregrep:
2745    
2746        (a) All non-match returns from pcre_exec() were being treated as failures
2747            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2748            error message is output. Some extra information is given for the
2749            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2750            probably the only errors that are likely to be caused by users (by
2751            specifying a regex that has nested indefinite repeats, for instance).
2752            If there are more than 20 of these errors, pcregrep is abandoned.
2753    
2754        (b) A binary zero was treated as data while matching, but terminated the
2755            output line if it was written out. This has been fixed: binary zeroes
2756            are now no different to any other data bytes.
2757    
2758        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2759            used to set a locale for matching. The --locale=xxxx long option has
2760            been added (no short equivalent) to specify a locale explicitly on the
2761            pcregrep command, overriding the environment variables.
2762    
2763        (d) When -B was used with -n, some line numbers in the output were one less
2764            than they should have been.
2765    
2766        (e) Added the -o (--only-matching) option.
2767    
2768        (f) If -A or -C was used with -c (count only), some lines of context were
2769            accidentally printed for the final match.
2770    
2771        (g) Added the -H (--with-filename) option.
2772    
2773        (h) The combination of options -rh failed to suppress file names for files
2774            that were found from directory arguments.
2775    
2776        (i) Added the -D (--devices) and -d (--directories) options.
2777    
2778        (j) Added the -F (--fixed-strings) option.
2779    
2780        (k) Allow "-" to be used as a file name for -f as well as for a data file.
2781    
2782        (l) Added the --colo(u)r option.
2783    
2784        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2785            is not present by default.
2786    
2787     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2788        items such as (?R) or (?1), when the recursion could match a number of
2789        alternatives. If it matched one of the alternatives, but subsequently,
2790        outside the recursion, there was a failure, the code tried to back up into
2791        the recursion. However, because of the way PCRE is implemented, this is not
2792        possible, and the result was an incorrect result from the match.
2793    
2794        In order to prevent this happening, the specification of recursion has
2795        been changed so that all such subpatterns are automatically treated as
2796        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2797    
2798     4. I had overlooked the fact that, in some locales, there are characters for
2799        which isalpha() is true but neither isupper() nor islower() are true. In
2800        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2801        and ordfeminine) are like this. This affected the treatment of \w and \W
2802        when they appeared in character classes, but not when they appeared outside
2803        a character class. The bit map for "word" characters is now created
2804        separately from the results of isalnum() instead of just taking it from the
2805        upper, lower, and digit maps. (Plus the underscore character, of course.)
2806    
2807     5. The above bug also affected the handling of POSIX character classes such as
2808        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2809        permanent tables. Instead, the bit maps for such a class were previously
2810        created as the appropriate unions of the upper, lower, and digit bitmaps.
2811        Now they are created by subtraction from the [[:word:]] class, which has
2812        its own bitmap.
2813    
2814     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2815        It is created by subtracting the vertical space characters (\x09, \x0a,
2816        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2817        subtraction was done in the overall bitmap for a character class, meaning
2818        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2819        be recognized. This bug has been fixed.
2820    
2821     7. Patches from the folks at Google:
2822    
2823          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2824          real life, but is still worth protecting against".
2825    
2826          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2827          regular expressions".
2828    
2829          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2830          have it.
2831    
2832          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2833          "configure" and the latter not, in order to fix a problem somebody had
2834          with compiling the Arg class on HP-UX.
2835    
2836          (e) Improve the error-handling of the C++ wrapper a little bit.
2837    
2838          (f) New tests for checking recursion limiting.
2839    
2840     8. The pcre_memmove() function, which is used only if the environment does not
2841        have a standard memmove() function (and is therefore rarely compiled),
2842        contained two bugs: (a) use of int instead of size_t, and (b) it was not
2843        returning a result (though PCRE never actually uses the result).
2844    
2845     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2846        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2847        returned instead of calling malloc() with an overflowing number that would
2848        most likely cause subsequent chaos.
2849    
2850    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2851    
2852    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2853        with this option is matched, the nmatch and pmatch options of regexec() are
2854        ignored.
2855    
2856    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2857        provided in case anyone wants to the the POSIX interface with UTF-8
2858        strings.
2859    
2860    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2861        C++ linking (needed for some HP-UX environments).
2862    
2863    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2864        (unused parameter) and in the pcre_printint() function (omitted "default"
2865        switch label when the default is to do nothing).
2866    
2867    15. Added some code to make it possible, when PCRE is compiled as a C++
2868        library, to replace subject pointers for pcre_exec() with a smart pointer
2869        class, thus making it possible to process discontinuous strings.
2870    
2871    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2872        much the same function. They were added by different people who were trying
2873        to make PCRE easy to compile on non-Unix systems. It has been suggested
2874        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2875        for compiling on Windows systems. I have therefore replaced it with
2876        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2877        defaults to "extern" for C or "extern C" for C++, which works fine on
2878        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2879        SCOPE with something explicit in config.h. In addition:
2880    
2881        (a) pcreposix.h still had just "extern" instead of either of these macros;
2882            I have replaced it with PCRE_DATA_SCOPE.
2883    
2884        (b) Functions such as _pcre_xclass(), which are internal to the library,
2885            but external in the C sense, all had PCRE_EXPORT in their definitions.
2886            This is apparently wrong for the Windows case, so I have removed it.
2887            (It makes no difference on Unix-like systems.)
2888    
2889    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2890        of recursive calls to match(). This is different to MATCH_LIMIT because
2891        that limits the total number of calls to match(), not all of which increase
2892        the depth of recursion. Limiting the recursion depth limits the amount of
2893        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2894        when PCRE is compiled, and changed at run time. A patch from Google adds
2895        this functionality to the C++ interface.
2896    
2897    18. Changes to the handling of Unicode character properties:
2898    
2899        (a) Updated the table to Unicode 4.1.0.
2900    
2901        (b) Recognize characters that are not in the table as "Cn" (undefined).
2902    
2903        (c) I revised the way the table is implemented to a much improved format
2904            which includes recognition of ranges. It now supports the ranges that
2905            are defined in UnicodeData.txt, and it also amalgamates other
2906            characters into ranges. This has reduced the number of entries in the
2907            table from around 16,000 to around 3,000, thus reducing its size
2908            considerably. I realized I did not need to use a tree structure after
2909            all - a binary chop search is just as efficient. Having reduced the
2910            number of entries, I extended their size from 6 bytes to 8 bytes to
2911            allow for more data.
2912    
2913        (d) Added support for Unicode script names via properties such as \p{Han}.
2914    
2915    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2916        matching that character.
2917    
2918    20. When matching a repeated Unicode property with a minimum greater than zero,
2919        (for example \pL{2,}), PCRE could look past the end of the subject if it
2920        reached it while seeking the minimum number of characters. This could
2921        happen only if some of the characters were more than one byte long, because
2922        there is a check for at least the minimum number of bytes.
2923    
2924    21. Refactored the implementation of \p and \P so as to be more general, to
2925        allow for more different types of property in future. This has changed the
2926        compiled form incompatibly. Anybody with saved compiled patterns that use
2927        \p or \P will have to recompile them.
2928    
2929    22. Added "Any" and "L&" to the supported property types.
2930    
2931    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2932        but give a compile time error if the value is greater than 0xff.
2933    
2934    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2935        accidentally not being installed or uninstalled.
2936    
2937    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2938        made were to insert the current release number. This seemed silly, because
2939        it made things harder for people building PCRE on systems that don't run
2940        "configure". I have turned pcre.h into a distributed file, no longer built
2941        by "configure", with the version identification directly included. There is
2942        no longer a pcre.h.in file.
2943    
2944        However, this change necessitated a change to the pcre-config script as
2945        well. It is built from pcre-config.in, and one of the substitutions was the
2946        release number. I have updated configure.ac so that ./configure now finds
2947        the release number by grepping pcre.h.
2948    
2949    26. Added the ability to run the tests under valgrind.
2950    
2951    
2952    Version 6.4 05-Sep-05
2953    ---------------------
2954    
2955     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2956        "--" to be printed when multiple files were scanned, even when none of the
2957        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2958        consider it to be a bug, and have restored the previous behaviour.
2959    
2960     2. A couple of code tidies to get rid of compiler warnings.
2961    
2962     3. The pcretest program used to cheat by referring to symbols in the library
2963        whose names begin with _pcre_. These are internal symbols that are not
2964        really supposed to be visible externally, and in some environments it is
2965        possible to suppress them. The cheating is now confined to including
2966        certain files from the library's source, which is a bit cleaner.
2967    
2968     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2969        file's purpose clearer.
2970    
2971     5. Reorganized pcre_ucp_findchar().
2972    
2973    
2974    Version 6.3 15-Aug-05
2975    ---------------------
2976    
2977     1. The file libpcre.pc.in did not have general read permission in the tarball.
2978    
2979     2. There were some problems when building without C++ support:
2980    
2981        (a) If C++ support was not built, "make install" and "make test" still
2982            tried to test it.
2983    
2984        (b) There were problems when the value of CXX was explicitly set. Some
2985            changes have been made to try to fix these, and ...
2986    
2987        (c) --disable-cpp can now be used to explicitly disable C++ support.
2988    
2989        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2990            backslash in a target when C++ was disabled. This confuses some
2991            versions of "make", apparently. Using an intermediate variable solves
2992            this. (Same for CPP_LOBJ.)
2993    
2994     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2995        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2996        necessary on certain architectures.
2997    
2998     4. Added a setting of -export-symbols-regex to the link command to remove
2999        those symbols that are exported in the C sense, but actually are local
3000        within the library, and not documented. Their names all begin with
3001        "_pcre_". This is not a perfect job, because (a) we have to except some
3002        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3003        available (and never for static libraries). I have made a note to try to
3004        find a way round (a) in the future.
3005    
3006    
3007    Version 6.2 01-Aug-05
3008    ---------------------
3009    
3010     1. There was no test for integer overflow of quantifier values. A construction
3011        such as {1111111111111111} would give undefined results. What is worse, if
3012        a minimum quantifier for a parenthesized subpattern overflowed and became
3013        negative, the calculation of the memory size went wrong. This could have
3014        led to memory overwriting.
3015    
3016     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3017    
3018     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3019        operating environments where this matters.
3020    
3021     4. Applied Giuseppe Maxia's patch to add additional features for controlling
3022        PCRE options from within the C++ wrapper.
3023    
3024     5. Named capturing subpatterns were not being correctly counted when a pattern
3025        was compiled. This caused two problems: (a) If there were more than 100
3026        such subpatterns, the calculation of the memory needed for the whole
3027        compiled pattern went wrong, leading to an overflow error. (b) Numerical
3028        back references of the form \12, where the number was greater than 9, were
3029        not recognized as back references, even though there were sufficient
3030        previous subpatterns.
3031    
3032     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3033        versions of gcc, e.g. 2.95.4.
3034    
3035    
3036    Version 6.1 21-Jun-05
3037    ---------------------
3038    
3039     1. There was one reference to the variable "posix" in pcretest.c that was not
3040        surrounded by "#if !defined NOPOSIX".
3041    
3042     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3043        the cross-check on the old pcre_info() function, for the benefit of the
3044        cut-down version of PCRE that is currently imported into Exim.
3045    
3046     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3047        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3048        patterns that start (?i) but I don't think that matters. The use of (?i) is
3049        just an example; this all applies to the other options as well.
3050    
3051     4. Since libtool seems to echo the compile commands it is issuing, the output
3052        from "make" can be reduced a bit by putting "@" in front of each libtool
3053        compile command.
3054    
3055     5. Patch from the folks at Google for configure.in to be a bit more thorough
3056        in checking for a suitable C++ installation before trying to compile the
3057        C++ stuff. This should fix a reported problem when a compiler was present,
3058        but no suitable headers.
3059    
3060     6. The man pages all had just "PCRE" as their title. I have changed them to
3061        be the relevant file name. I have also arranged that these names are
3062        retained in the file doc/pcre.txt, which is a concatenation in text format
3063        of all the man pages except the little individual ones for each function.
3064    
3065     7. The NON-UNIX-USE file had not been updated for the different set of source
3066        files that come with release 6. I also added a few comments about the C++
3067        wrapper.
3068    
3069    
3070    Version 6.0 07-Jun-05
3071    ---------------------
3072    
3073     1. Some minor internal re-organization to help with my DFA experiments.
3074    
3075     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3076        didn't matter for the library itself when fully configured, but did matter
3077        when compiling without UCP support, or within Exim, where the ucp files are
3078        not imported.
3079    
3080     3. Refactoring of the library code to split up the various functions into
3081        different source modules. The addition of the new DFA matching code (see
3082        below) to a single monolithic source would have made it really too
3083        unwieldy, quite apart from causing all the code to be include in a
3084        statically linked application, when only some functions are used. This is
3085        relevant even without the DFA addition now that patterns can be compiled in
3086        one application and matched in another.
3087    
3088        The downside of splitting up is that there have to be some external
3089        functions and data tables that are used internally in different modules of
3090        the library but which are not part of the API. These have all had their
3091        names changed to start with "_pcre_" so that they are unlikely to clash
3092        with other external names.
3093    
3094     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3095        a different (DFA) algorithm. Although it is slower than the original
3096        function, it does have some advantages for certain types of matching
3097        problem.
3098    
3099     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3100        including restarting after a partial match.
3101    
3102     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3103        defined when compiling for Windows was sent to me. I have put it into the
3104        code, though I have no means of testing or verifying it.
3105    
3106     7. Added the pcre_refcount() auxiliary function.
3107    
3108     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3109        match before or at the first newline in the subject string. In pcretest,
3110        the /f option on a pattern can be used to set this.
3111    
3112     9. A repeated \w when used in UTF-8 mode with characters greater than 256
3113        would behave wrongly. This has been present in PCRE since release 4.0.
3114    
3115    10. A number of changes to the pcregrep command:
3116    
3117        (a) Refactored how -x works; insert ^(...)$ instead of setting
3118            PCRE_ANCHORED and checking the length, in preparation for adding
3119            something similar for -w.
3120    
3121        (b) Added the -w (match as a word) option.
3122    
3123        (c) Refactored the way lines are read and buffered so as to have more
3124            than one at a time available.
3125    
3126        (d) Implemented a pcregrep test script.
3127    
3128        (e) Added the -M (multiline match) option. This allows patterns to match
3129            over several lines of the subject. The buffering ensures that at least
3130            8K, or the rest of the document (whichever is the shorter) is available
3131            for matching (and similarly the previous 8K for lookbehind assertions).
3132    
3133        (f) Changed the --help output so that it now says
3134    
3135              -w, --word-regex(p)
3136    
3137            instead of two lines, one with "regex" and the other with "regexp"
3138            because that confused at least one person since the short forms are the
3139            same. (This required a bit of code, as the output is generated
3140            automatically from a table. It wasn't just a text change.)
3141    
3142        (g) -- can be used to terminate pcregrep options if the next thing isn't an
3143            option but starts with a hyphen. Could be a pattern or a path name
3144            starting with a hyphen, for instance.
3145    
3146        (h) "-" can be given as a file name to represent stdin.
3147    
3148        (i) When file names are being printed, "(standard input)" is used for
3149            the standard input, for compatibility with GNU grep. Previously
3150            "<stdin>" was used.
3151    
3152        (j) The option --label=xxx can be used to supply a name to be used for
3153            stdin when file names are being printed. There is no short form.
3154    
3155        (k) Re-factored the options decoding logic because we are going to add
3156            two more options that take data. Such options can now be given in four
3157            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3158    
3159        (l) Added the -A, -B, and -C options for requesting that lines of context
3160            around matches be printed.
3161    
3162        (m) Added the -L option to print the names of files that do not contain
3163            any matching lines, that is, the complement of -l.
3164    
3165        (n) The return code is 2 if any file cannot be opened, but pcregrep does
3166            continue to scan other files.
3167    
3168        (o) The -s option was incorrectly implemented. For compatibility with other
3169            greps, it now suppresses the error message for a non-existent or non-
3170            accessible file (but not the return code). There is a new option called
3171            -q that suppresses the output of matching lines, which was what -s was
3172            previously doing.
3173    
3174        (p) Added --include and --exclude options to specify files for inclusion
3175            and exclusion when recursing.
3176    
3177    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3178        Hopefully, it now does.
3179    
3180    12. Missing cast in pcre_study().
3181    
3182    13. Added an "uninstall" target to the makefile.
3183    
3184    14. Replaced "extern" in the function prototypes in Makefile.in with
3185        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3186        world, but is set differently for Windows.
3187    
3188    15. Added a second compiling function called pcre_compile2(). The only
3189        difference is that it has an extra argument, which is a pointer to an
3190        integer error code. When there is a compile-time failure, this is set
3191        non-zero, in addition to the error test pointer being set to point to an
3192        error message. The new argument may be NULL if no error number is required
3193        (but then you may as well call pcre_compile(), which is now just a
3194        wrapper). This facility is provided because some applications need a
3195        numeric error indication, but it has also enabled me to tidy up the way
3196        compile-time errors are handled in the POSIX wrapper.
3197    
3198    16. Added VPATH=.libs to the makefile; this should help when building with one
3199        prefix path and installing with another. (Or so I'm told by someone who
3200        knows more about this stuff than I do.)
3201    
3202    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3203        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3204        match everything, including newlines. This is not POSIX-compatible, but
3205        somebody wanted the feature. From pcretest it can be activated by using
3206        both the P and the s flags.
3207    
3208    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3209    
3210    19. libpcre.pc was being incorrectly installed as executable.
3211    
3212    20. A couple of places in pcretest check for end-of-line by looking for '\n';
3213        it now also looks for '\r' so that it will work unmodified on Windows.
3214    
3215    21. Added Google's contributed C++ wrapper to the distribution.
3216    
3217    22. Added some untidy missing memory free() calls in pcretest, to keep
3218        Electric Fence happy when testing.
3219    
3220    
3221    
3222    Version 5.0 13-Sep-04
3223    ---------------------
3224    
3225     1. Internal change: literal characters are no longer packed up into items
3226        containing multiple characters in a single byte-string. Each character
3227        is now matched using a separate opcode. However, there may be more than one
3228        byte in the character in UTF-8 mode.
3229    
3230     2. The pcre_callout_block structure has two new fields: pattern_position and
3231        next_item_length. These contain the offset in the pattern to the next match
3232        item, and its length, respectively.
3233    
3234     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3235        insertion of callouts before each pattern item. Added the /C option to
3236        pcretest to make use of this.
3237    
3238     4. On the advice of a Windows user, the lines
3239    
3240          #if defined(_WIN32) || defined(WIN32)
3241          _setmode( _fileno( stdout ), 0x8000 );
3242          #endif  /* defined(_WIN32) || defined(WIN32) */
3243    
3244        have been added to the source of pcretest. This apparently does useful
3245        magic in relation to line terminators.
3246    
3247     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3248        for the benefit of those environments where the "b" makes a difference.
3249    
3250     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3251        to know about it. I have put a hack into configure.in that adds in code
3252        to set GCC=yes if CC=icc. This seems to end up at a point in the
3253        generated configure script that is early enough to affect the setting of
3254        compiler options, which is what is needed, but I have no means of testing
3255        whether it really works. (The user who reported this had patched the
3256        generated configure script, which of course I cannot do.)
3257    
3258        LATER: After change 22 below (new libtool files), the configure script
3259        seems to know about icc (and also ecc). Therefore, I have commented out
3260        this hack in configure.in.
3261    
3262     7. Added support for pkg-config (2 patches were sent in).
3263    
3264     8. Negated POSIX character classes that used a combination of internal tables
3265        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3266        [[:^ascii]]. Typically, they would match almost any characters. The other
3267        POSIX classes were not broken in this way.
3268    
3269     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3270        to find the match, as PCRE was deluded into thinking that the match had to
3271        start at the start point or following a newline. The same bug applied to
3272        patterns with negative forward assertions or any backward assertions
3273        preceding ".*" at the start, unless the pattern required a fixed first
3274        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3275    
3276    10. In UTF-8 mode, when moving forwards in the subject after a failed match
3277        starting at the last subject character, bytes beyond the end of the subject
3278        string were read.
3279    
3280    11. Renamed the variable "class" as "classbits" to make life easier for C++
3281        users. (Previously there was a macro definition, but it apparently wasn't
3282        enough.)
3283    
3284    12. Added the new field "tables" to the extra data so that tables can be passed
3285        in at exec time, or the internal tables can be re-selected. This allows
3286        a compiled regex to be saved and re-used at a later time by a different
3287        program that might have everything at different addresses.
3288    
3289    13. Modified the pcre-config script so that, when run on Solaris, it shows a
3290        -R library as well as a -L library.
3291    
3292    14. The debugging options of pcretest (-d on the command line or D on a
3293        pattern) showed incorrect output for anything following an extended class
3294        that contained multibyte characters and which was followed by a quantifier.
3295    
3296    15. Added optional support for general category Unicode character properties
3297        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3298        support. It adds about 90K to the size of the library. The meanings of the
3299        inbuilt class escapes such as \d and \s have NOT been changed.
3300    
3301    16. Updated pcredemo.c to include calls to free() to release the memory for the
3302        compiled pattern.
3303    
3304    17. The generated file chartables.c was being created in the source directory
3305        instead of in the building directory. This caused the build to fail if the
3306        source directory was different from the building directory, and was
3307        read-only.
3308    
3309    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3310        file. No doubt somebody will tell me if they don't make sense... Also added
3311        Dan Mooney's comments about building on OpenVMS.
3312    
3313    19. Added support for partial matching via the PCRE_PARTIAL option for
3314        pcre_exec() and the \P data escape in pcretest.
3315    
3316    20. Extended pcretest with 3 new pattern features:
3317    
3318        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
3319              write the compiled pattern to the file whose name is "rest-of-line".
3320              This is a straight binary dump of the data, with the saved pointer to
3321              the character tables forced to be NULL. The study data, if any, is
3322              written too. After writing, pcretest reads a new pattern.
3323    
3324        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3325              compiled pattern from the given file. There must not be any
3326              occurrences of "<" in the file name (pretty unlikely); if there are,
3327              pcretest will instead treat the initial "<" as a pattern delimiter.
3328              After reading in the pattern, pcretest goes on to read data lines as
3329              usual.
3330    
3331        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3332              and 16-bit fields in a compiled pattern, to simulate a pattern that
3333              was compiled on a host of opposite endianness.
3334    
3335    21. The pcre-exec() function can now cope with patterns that were compiled on
3336        hosts of opposite endianness, with this restriction:
3337    
3338          As for any compiled expression that is saved and used later, the tables
3339          pointer field cannot be preserved; the extra_data field in the arguments
3340          to pcre_exec() should be used to pass in a tables address if a value
3341          other than the default internal tables were used at compile time.
3342    
3343    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3344        now diagnosed as an error. Previously, most of the time, a negative number
3345        would have been treated as zero, but if in addition "ovector" was passed as
3346        NULL, a crash could occur.
3347    
3348    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3349        new versions from the libtool 1.5 distribution (the last one is a copy of
3350        a file called libtool.m4). This seems to have fixed the need to patch
3351        "configure" to support Darwin 1.3 (which I used to do). However, I still
3352        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3353        workstation).
3354    
3355    24. Changed the PCRE licence to be the more standard "BSD" licence.
3356    
3357    
3358    Version 4.5 01-Dec-03
3359    ---------------------
3360    
3361     1. There has been some re-arrangement of the code for the match() function so
3362        that it can be compiled in a version that does not call itself recursively.
3363        Instead, it keeps those local variables that need separate instances for
3364        each "recursion" in a frame on the heap, and gets/frees frames whenever it
3365        needs to "recurse". Keeping track of where control must go is done by means
3366        of setjmp/longjmp. The whole thing is implemented by a set of macros that
3367        hide most of the details from the main code, and operates only if
3368        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3369        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3370        operating.
3371    
3372        To make it easier for callers to provide specially tailored get/free
3373        functions for this usage, two new functions, pcre_stack_malloc, and
3374        pcre_stack_free, are used. They are always called in strict stacking order,
3375        and the size of block requested is always the same.
3376    
3377        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3378        PCRE has been compiled to use the stack or the heap for recursion. The
3379        -C option of pcretest uses this to show which version is compiled.
3380    
3381        A new data escape \S, is added to pcretest; it causes the amounts of store
3382        obtained and freed by both kinds of malloc/free at match time to be added
3383        to the output.
3384    
3385     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3386        what's available on my current Linux desktop machine.
3387    
3388     3. When matching a UTF-8 string, the test for a valid string at the start has
3389        been extended. If start_offset is not zero, PCRE now checks that it points
3390        to a byte that is the start of a UTF-8 character. If not, it returns
3391        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3392        this is necessary because there may be backward assertions in the pattern.
3393        When matching the same subject several times, it may save resources to use
3394        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3395    
3396     4. The code for checking the validity of UTF-8 strings has been tightened so
3397        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3398        containing "overlong sequences".
3399    
3400     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3401        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3402        should have been "&", but it just so happened that all the cases this let
3403        through by mistake were picked up later in the function.
3404    
3405     6. I had used a variable called "isblank" - this is a C99 function, causing
3406        some compilers to warn. To avoid this, I renamed it (as "blankclass").
3407    
3408     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3409        prompting; (b) run "./pcretest /dev/null" at the start of the test script
3410        so the version is shown; (c) stop "make test" echoing "./RunTest".
3411    
3412     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3413    
3414     9. The prototype for memmove() for systems that don't have it was using
3415        size_t, but the inclusion of the header that defines size_t was later. I've
3416        moved the #includes for the C headers earlier to avoid this.
3417    
3418    10. Added some adjustments to the code to make it easier to compiler on certain
3419        special systems:
3420    
3421          (a) Some "const" qualifiers were missing.
3422          (b) Added the macro EXPORT before all exported functions; by default this
3423              is defined to be empty.
3424          (c) Changed the dftables auxiliary program (that builds chartables.c) so
3425              that it reads its output file name as an argument instead of writing
3426              to the standard output and assuming this can be redirected.
3427    
3428    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3429        class containing characters with values greater than 255, PCRE compilation
3430        went into a loop.
3431    
3432    12. A recursive reference to a subpattern that was within another subpattern
3433        that had a minimum quantifier of zero caused PCRE to crash. For example,
3434        (x(y(?2))z)? provoked this bug with a subject that got as far as the
3435        recursion. If the recursively-called subpattern itself had a zero repeat,
3436        that was OK.
3437    
3438    13. In pcretest, the buffer for reading a data line was set at 30K, but the
3439        buffer into which it was copied (for escape processing) was still set at
3440        1024, so long lines caused crashes.
3441    
3442    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3443        "internal error: code overflow...". This applied to any character class
3444        that was followed by a possessive quantifier.
3445    
3446    15. Modified the Makefile to add libpcre.la as a prerequisite for
3447        libpcreposix.la because I was told this is needed for a parallel build to
3448        work.
3449    
3450    16. If a pattern that contained .* following optional items at the start was
3451        studied, the wrong optimizing data was generated, leading to matching
3452        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3453        matching string must start with a or b or c. The correct conclusion for
3454        this pattern is that a match can start with any character.
3455    
3456    
3457    Version 4.4 13-Aug-03
3458    ---------------------
3459    
3460     1. In UTF-8 mode, a character class containing characters with values between
3461        127 and 255 was not handled correctly if the compiled pattern was studied.
3462        In fixing this, I have also improved the studying algorithm for such
3463        classes (slightly).
3464    
3465     2. Three internal functions had redundant arguments passed to them. Removal
3466        might give a very teeny performance improvement.
3467    
3468     3. Documentation bug: the value of the capture_top field in a callout is *one
3469        more than* the number of the hightest numbered captured substring.
3470    
3471     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3472        in incorrectly linking with a previously installed version. They now link
3473        explicitly with libpcre.la.
3474    
3475     5. configure.in no longer needs to recognize Cygwin specially.
3476    
3477     6. A problem in pcre.in for Windows platforms is fixed.
3478    
3479     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3480        pcretest, it used to include the size of the study block as part of its
3481        output. Unfortunately, the structure contains a field that has a different
3482        size on different hardware architectures. This meant that the tests that
3483        showed this size failed. As the block is currently always of a fixed size,
3484        this information isn't actually particularly useful in pcretest output, so
3485        I have just removed it.
3486    
3487     8. Three pre-processor statements accidentally did not start in column 1.
3488        Sadly, there are *still* compilers around that complain, even though
3489        standard C has not required this for well over a decade. Sigh.
3490    
3491     9. In pcretest, the code for checking callouts passed small integers in the
3492        callout_data field, which is a void * field. However, some picky compilers
3493        complained about the casts involved for this on 64-bit systems. Now
3494        pcretest passes the address of the small integer instead, which should get
3495        rid of the warnings.
3496    
3497    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3498        both compile and run time, and gives an error if an invalid UTF-8 sequence
3499        is found. There is a option for disabling this check in cases where the
3500        string is known to be correct and/or the maximum performance is wanted.
3501    
3502    11. In response to a bug report, I changed one line in Makefile.in from
3503    
3504            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3505        to
3506            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3507    
3508        to look similar to other lines, but I have no way of telling whether this
3509        is the right thing to do, as I do not use Windows. No doubt I'll get told
3510        if it's wrong...
3511    
3512    
3513    Version 4.3 21-May-03
3514    ---------------------
3515    
3516    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3517       Makefile.
3518    
3519    2. Some refactoring to improve the quality of the code:
3520    
3521       (i)   The utf8_table... variables are now declared "const".
3522    
3523       (ii)  The code for \cx, which used the "case flipping" table to upper case
3524             lower case letters, now just substracts 32. This is ASCII-specific,
3525             but the whole concept of \cx is ASCII-specific, so it seems
3526             reasonable.
3527    
3528       (iii) PCRE was using its character types table to recognize decimal and
3529             hexadecimal digits in the pattern. This is silly, because it handles
3530             only 0-9, a-f, and A-F, but the character types table is locale-
3531             specific, which means strange things might happen. A private
3532             table is now used for this - though it costs 256 bytes, a table is
3533             much faster than multiple explicit tests. Of course, the standard
3534             character types table is still used for matching digits in subject
3535             strings against \d.
3536    
3537       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3538             ending in _t are). So I've renamed it as ESC_tee.
3539    
3540    3. The first argument for regexec() in the POSIX wrapper should have been
3541       defined as "const".
3542    
3543    4. Changed pcretest to use malloc() for its buffers so that they can be
3544       Electric Fenced for debugging.
3545    
3546    5. There were several places in the code where, in UTF-8 mode, PCRE would try
3547       to read one or more bytes before the start of the subject string. Often this
3548       had no effect on PCRE's behaviour, but in some circumstances it could
3549       provoke a segmentation fault.
3550    
3551    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3552       to try to read one or more bytes before the start of the subject string.
3553    
3554    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3555       UTF-8 support could misbehave in various ways if the subject string
3556       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3557       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3558       back over UTF-8 characters.)
3559    
3560    
3561    Version 4.2 14-Apr-03
3562    ---------------------
3563    
3564    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3565    
3566    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3567         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3568         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3569         [WIN_PREFIX]: new variable, "cyg" for Cygwin
3570         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3571           and BUILD_EXEEXT
3572         Note: automatic setting of the BUILD variables is not yet working
3573         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3574           compile-time but not at link-time
3575         [LINK]: use for linking executables only
3576         make different versions for Windows and non-Windows
3577         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3578           libraries
3579         [LINK_FOR_BUILD]: new variable
3580         [OBJEXT]: use throughout
3581         [EXEEXT]: use throughout
3582         <winshared>: new target
3583         <wininstall>: new target
3584         <dftables.o>: use native compiler
3585         <dftables>: use native linker
3586         <install>: handle Windows platform correctly
3587         <clean>: ditto
3588         <check>: ditto
3589         copy DLL to top builddir before testing
3590    
3591       As part of these changes, -no-undefined was removed again. This was reported
3592       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3593       in any case.
3594    
3595    3. Some tidies to get rid of compiler warnings:
3596    
3597       . In the match_data structure, match_limit was an unsigned long int, whereas
3598         match_call_count was an int. I've made them both unsigned long ints.
3599    
3600       . In pcretest the fact that a const uschar * doesn't automatically cast to
3601         a void * provoked a warning.
3602    
3603       . Turning on some more compiler warnings threw up some "shadow" variables
3604         and a few more missing casts.
3605    
3606    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3607       option, a class that contained a single character with a value between 128
3608       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3609    
3610    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3611       option, a class that contained several characters, but with at least one
3612       whose value was between 128 and 255 caused PCRE to crash.
3613    
3614    
3615    Version 4.1 12-Mar-03
3616    ---------------------
3617    
3618    1. Compiling with gcc -pedantic found a couple of places where casts were
3619    needed, and a string in dftables.c that was longer than standard compilers are
3620    required to support.
3621    
3622    2. Compiling with Sun's compiler found a few more places where the code could
3623    be tidied up in order to avoid warnings.
3624    
3625    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3626    first of these names is deprecated in the latest Autoconf in favour of the name
3627    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3628    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3629    analogy I have changed it to CFLAGS_FOR_BUILD.
3630    
3631    4. Added -no-undefined to the linking command in the Makefile, because this is
3632    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3633    linking step for the pcreposix library.
3634    
3635    5. PCRE was failing to diagnose the case of two named groups with the same
3636    name.
3637    
3638    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3639    literal character that is needed in the subject for a match, and scans along to
3640    ensure that it is present before embarking on the full matching process. This
3641    saves time in cases of nested unlimited repeats that are never going to match.
3642    Problem: the scan can take a lot of time if the subject is very long (e.g.
3643    megabytes), thus penalizing straightforward matches. It is now done only if the
3644    amount of subject to be scanned is less than 1000 bytes.
3645    
3646    7. A lesser problem with the same optimization is that it was recording the
3647    first character of an anchored pattern as "needed", thus provoking a search
3648    right along the subject, even when the first match of the pattern was going to
3649    fail. The "needed" character is now not set for anchored patterns, unless it
3650    follows something in the pattern that is of non-fixed length. Thus, it still
3651    fulfils its original purpose of finding quick non-matches in cases of nested
3652    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3653    
3654    
3655    Version 4.0 17-Feb-03
3656    ---------------------
3657    
3658  1. If a comment in an extended regex that started immediately after a meta-item  1. If a comment in an extended regex that started immediately after a meta-item
3659  extended to the end of string, PCRE compiled incorrect data. This could lead to  extended to the end of string, PCRE compiled incorrect data. This could lead to
3660  all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.  all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.

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