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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 12-Nov-07  Version 8.33 28-April-2013
5    --------------------------
6    
7    1.  Added 'U' to some constants that are compared to unsigned integers, to
8        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
9        variables that are added to signed variables, to ensure the result is
10        signed and can be negated.
11    
12    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
13        CMake config files.
14    
15    3.  Revise the creation of config.h.generic so that all boolean macros are
16        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
17        overriding via -D on the command line possible.
18    
19    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
20        to unsigned int is reported to make a quite noticeable speed difference in
21        a specific Windows environment. Testing on Linux did also appear to show
22        some benefit (and it is clearly not harmful). Also fixed the definition of
23        Xop which should be unsigned.
24    
25    5.  Related to (4), changing the definition of the intermediate variable cc
26        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
27        improvements.
28    
29    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
30        unnecessary spaces.
31    
32    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
33        and later.
34    
35    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
36    
37    9.  Optimizing fast_forward_start_bits in JIT.
38    
39    10. Adding experimental support for callouts in JIT, and fixing some
40        issues revealed during this work. Namely:
41    
42        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
43    
44        (b) Minimum length was not checked before the matching is started.
45    
46    11. The value of capture_last that is passed to callouts was incorrect in some
47        cases when there was a capture on one path that was subsequently abandoned
48        after a backtrack. Also, the capture_last value is now reset after a
49        recursion, since all captures are also reset in this case.
50    
51    12. The interpreter no longer returns the "too many substrings" error in the
52        case when an overflowing capture is in a branch that is subsequently
53        abandoned after a backtrack.
54    
55    13. In the pathological case when an offset vector of size 2 is used, pcretest
56        now prints out the matched string after a yield of 0 or 1.
57    
58    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
59        Only supported by the JIT compiler at the moment.
60    
61    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
62    
63    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
64        offset of the starting point of the matching process, provided the offsets
65        vector is large enough.
66    
67    17. The \A escape now records a lookbehind value of 1, though its execution
68        does not actually inspect the previous character. This is to ensure that,
69        in partial multi-segment matching, at least one character from the old
70        segment is retained when a new segment is processed. Otherwise, if there
71        are no lookbehinds in the pattern, \A might match incorrectly at the start
72        of a new segment.
73    
74    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
75    
76    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
77        gives some modest performance improvement in 8-bit mode.
78    
79    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
80        be expressed in certain programming languages using Universal Character
81        Names.
82    
83    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
84        which points out that "non characters" are not "characters that may not
85        appear in Unicode strings" but rather "characters that are reserved for
86        internal use and have only local meaning".
87    
88    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
89        there was a conditional group that depended on an assertion, if the
90        assertion was false, the callout that immediately followed the alternation
91        in the condition was skipped when pcre_exec() was used for matching.
92    
93    23. Allow an explicit callout to be inserted before an assertion that is the
94        condition for a conditional group, for compatibility with automatic
95        callouts, which always insert a callout at this point.
96    
97    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
98        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
99    
100    25. (*PRUNE) is now supported by the JIT compiler.
101    
102    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
103    
104    27. Fix the case where there are two or more SKIPs with arguments that may be
105        ignored.
106    
107    28. (*SKIP) is now supported by the JIT compiler.
108    
109    29. (*THEN) is now supported by the JIT compiler.
110    
111    30. Update RunTest with additional test selector options.
112    
113    31. The way PCRE handles backtracking verbs has been changed in two ways.
114    
115        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
116        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
117        backtracking. In some cases this makes it more Perl-compatible, but Perl's
118        rather obscure rules do not always do the same thing.
119    
120        (2) Previously, backtracking verbs were confined within assertions. This is
121        no longer the case for positive assertions, except for (*ACCEPT). Again,
122        this sometimes improves Perl compatibility, and sometimes does not.
123    
124    32. A number of tests that were in test 2 because Perl did things differently
125        have been moved to test 1, because either Perl or PCRE has changed, and
126        these tests are now compatible.
127    
128    32. Control verbs are handled in the same way in JIT and interpreter.
129    
130    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
131        contained a forward subroutine reference caused a compile error.
132    
133    34. Auto-detect and optimize limited repetitions in JIT.
134    
135    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
136        blocking (*UTF) etc.
137    
138    36. In the interpreter, maximizing pattern repetitions for characters and
139        character types now use tail recursion, which reduces stack usage.
140    
141    37. The value of the max lookbehind was not correctly preserved if a compiled
142        and saved regex was reloaded on a host of different endianness.
143    
144    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
145        of the compiled pattern block, expand the flags field from 16 to 32 bits
146        because it was almost full.
147    
148    39. Try madvise first before posix_madvise.
149    
150    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
151        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
152        original change locked out all matches of empty strings. This has been
153        changed so that one match of an empty string per line is recognized.
154        Subsequent searches on the same line (for colouring or for --only-matching,
155        for example) do not recognize empty strings.
156    
157    41. Applied a user patch to fix a number of spelling mistakes in comments.
158    
159    
160    Version 8.32 30-November-2012
161    -----------------------------
162    
163    1.  Improved JIT compiler optimizations for first character search and single
164        character iterators.
165    
166    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
167        Patch by Daniel Richard G.
168    
169    3.  Single character iterator optimizations in the JIT compiler.
170    
171    4.  Improved JIT compiler optimizations for character ranges.
172    
173    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
174        Reported by Giuseppe D'Angelo.
175    
176    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
177        of a line, was being set incorrectly in cases where .* appeared inside
178        atomic brackets at the start of a pattern, or where there was a subsequent
179        *PRUNE or *SKIP.
180    
181    7.  Improved instruction cache flush for POWER/PowerPC.
182        Patch by Daniel Richard G.
183    
184    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
185        grep:
186    
187        (a) There is now no limit to the number of patterns to be matched.
188    
189        (b) An error is given if a pattern is too long.
190    
191        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
192            are now supported.
193    
194        (d) --exclude-from and --include-from (multiple use) have been added.
195    
196        (e) Exclusions and inclusions now apply to all files and directories, not
197            just to those obtained from scanning a directory recursively.
198    
199        (f) Multiple uses of -f and --file-list are now supported.
200    
201        (g) In a Windows environment, the default for -d has been changed from
202            "read" (the GNU grep default) to "skip", because otherwise the presence
203            of a directory in the file list provokes an error.
204    
205        (h) The documentation has been revised and clarified in places.
206    
207    9.  Improve the matching speed of capturing brackets.
208    
209    10. Changed the meaning of \X so that it now matches a Unicode extended
210        grapheme cluster.
211    
212    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
213        out POSIX threads when JIT support is configured.
214    
215    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
216    
217    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
218        structure could go wrong in environments where size_t is not the same size
219        as int.
220    
221    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
222        set.
223    
224    15. The EBCDIC support had decayed; later updates to the code had included
225        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
226        general tidy up of EBCDIC-related issues, and the documentation was also
227        not quite right. There is now a test that can be run on ASCII systems to
228        check some of the EBCDIC-related things (but is it not a full test).
229    
230    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
231        in a small tidy to the code.
232    
233    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
234    
235    18. If the --only-matching (-o) option in pcregrep is specified multiple
236        times, each one causes appropriate output. For example, -o1 -o2 outputs the
237        substrings matched by the 1st and 2nd capturing parentheses. A separating
238        string can be specified by --om-separator (default empty).
239    
240    19. Improving the first n character searches.
241    
242    20. Turn case lists for horizontal and vertical white space into macros so that
243        they are defined only once.
244    
245    21. This set of changes together give more compatible Unicode case-folding
246        behaviour for characters that have more than one other case when UCP
247        support is available.
248    
249        (a) The Unicode property table now has offsets into a new table of sets of
250            three or more characters that are case-equivalent. The MultiStage2.py
251            script that generates these tables (the pcre_ucd.c file) now scans
252            CaseFolding.txt instead of UnicodeData.txt for character case
253            information.
254    
255        (b) The code for adding characters or ranges of characters to a character
256            class has been abstracted into a generalized function that also handles
257            case-independence. In UTF-mode with UCP support, this uses the new data
258            to handle characters with more than one other case.
259    
260        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
261            whose other case is greater than 256 are now correctly matched
262            caselessly. Previously, the high codepoint matched the low one, but not
263            vice versa.
264    
265        (d) The processing of \h, \H, \v, and \ in character classes now makes use
266            of the new class addition function, using character lists defined as
267            macros alongside the case definitions of 20 above.
268    
269        (e) Caseless back references now work with characters that have more than
270            one other case.
271    
272        (f) General caseless matching of characters with more than one other case
273            is supported.
274    
275    22. Unicode character properties were updated from Unicode 6.2.0
276    
277    23. Improved CMake support under Windows. Patch by Daniel Richard G.
278    
279    24. Add support for 32-bit character strings, and UTF-32
280    
281    25. Major JIT compiler update (code refactoring and bugfixing).
282        Experimental Sparc 32 support is added.
283    
284    26. Applied a modified version of Daniel Richard G's patch to create
285        pcre.h.generic and config.h.generic by "make" instead of in the
286        PrepareRelease script.
287    
288    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
289        pcre_compile.c when checking for a zero character.
290    
291    28. Introducing a native interface for JIT. Through this interface, the compiled
292        machine code can be directly executed. The purpose of this interface is to
293        provide fast pattern matching, so several sanity checks are not performed.
294        However, feature tests are still performed. The new interface provides
295        1.4x speedup compared to the old one.
296    
297    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
298        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
299        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
300    
301    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
302        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
303        the "old" RFC 2279). Instead, it ended up passing a negative length to
304        pcre_exec().
305    
306    31. Add support for GCC's visibility feature to hide internal functions.
307    
308    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
309        "unknown -C option" after outputting 0 or 1.
310    
311    33. There is now support for generating a code coverage report for the test
312        suite in environments where gcc is the compiler and lcov is installed. This
313        is mainly for the benefit of the developers.
314    
315    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
316        unaddressable using valgrind annotations, allowing valgrind to detect
317        invalid memory accesses. This is mainly for the benefit of the developers.
318    
319    25. (*UTF) can now be used to start a pattern in any of the three libraries.
320    
321    26. Give configure error if --enable-cpp but no C++ compiler found.
322    
323    
324    Version 8.31 06-July-2012
325    -------------------------
326    
327    1.  Fixing a wrong JIT test case and some compiler warnings.
328    
329    2.  Removed a bashism from the RunTest script.
330    
331    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
332        to unsigned type, result still unsigned" that was given by an MS compiler
333        on encountering the code "-sizeof(xxx)".
334    
335    4.  Partial matching support is added to the JIT compiler.
336    
337    5.  Fixed several bugs concerned with partial matching of items that consist
338        of more than one character:
339    
340        (a) /^(..)\1/ did not partially match "aba" because checking references was
341            done on an "all or nothing" basis. This also applied to repeated
342            references.
343    
344        (b) \R did not give a hard partial match if \r was found at the end of the
345            subject.
346    
347        (c) \X did not give a hard partial match after matching one or more
348            characters at the end of the subject.
349    
350        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
351            a partial match for the string "\r".
352    
353        (e) When newline was set to CRLF, the metacharacter "." did not recognize
354            a partial match for a CR character at the end of the subject string.
355    
356    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
357        running pcretest, the text "(JIT)" added to the output whenever JIT is
358        actually used to run the match.
359    
360    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
361        or /S+[+] with a digit between 1 and 7.
362    
363    8.  OP_NOT now supports any UTF character not just single-byte ones.
364    
365    9.  (*MARK) control verb is now supported by the JIT compiler.
366    
367    10. The command "./RunTest list" lists the available tests without actually
368        running any of them. (Because I keep forgetting what they all are.)
369    
370    11. Add PCRE_INFO_MAXLOOKBEHIND.
371    
372    12. Applied a (slightly modified) user-supplied patch that improves performance
373        when the heap is used for recursion (compiled with --disable-stack-for-
374        recursion). Instead of malloc and free for each heap frame each time a
375        logical recursion happens, frames are retained on a chain and re-used where
376        possible. This sometimes gives as much as 30% improvement.
377    
378    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
379        call.
380    
381    14. As documented, (*COMMIT) is now confined to within a positive assertion.
382    
383    15. It is now possible to link pcretest with libedit as an alternative to
384        libreadline.
385    
386    16. (*COMMIT) control verb is now supported by the JIT compiler.
387    
388    17. The Unicode data tables have been updated to Unicode 6.1.0.
389    
390    18. Added --file-list option to pcregrep.
391    
392    19. Added binary file support to pcregrep, including the -a, --binary-files,
393        -I, and --text options.
394    
395    20. The madvise function is renamed for posix_madvise for QNX compatibility
396        reasons. Fixed by Giuseppe D'Angelo.
397    
398    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
399    
400    22. Changed the option for creating symbolic links for 16-bit man pages from
401        -s to -sf so that re-installing does not cause issues.
402    
403    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
404    
405    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
406        matches in certain environments (the workspace was not being correctly
407        retained). Also added to pcre_dfa_exec() a simple plausibility check on
408        some of the workspace data at the beginning of a restart.
409    
410    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
411        was not doing so when it should - probably a typo introduced by SVN 528
412        (change 8.10/14).
413    
414    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
415        \w+ when the character tables indicated that \x{c4} was a word character.
416        There were several related cases, all because the tests for doing a table
417        lookup were testing for characters less than 127 instead of 255.
418    
419    27. If a pattern contains capturing parentheses that are not used in a match,
420        their slots in the ovector are set to -1. For those that are higher than
421        any matched groups, this happens at the end of processing. In the case when
422        there were back references that the ovector was too small to contain
423        (causing temporary malloc'd memory to be used during matching), and the
424        highest capturing number was not used, memory off the end of the ovector
425        was incorrectly being set to -1. (It was using the size of the temporary
426        memory instead of the true size.)
427    
428    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
429        ovector size, it uses memory at the end of the block that it has got.
430    
431    29. Check for an overlong MARK name and give an error at compile time. The
432        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
433    
434    30. JIT compiler update.
435    
436    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
437        Rill for the patch.
438    
439    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
440    
441    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
442    
443    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
444        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
445        was enabled.
446    
447    35. Improve JIT code generation for greedy plus quantifier.
448    
449    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
450        1 to "aa" instead of to an empty string. The bug affected repeated groups
451        that could potentially match an empty string.
452    
453    37. Optimizing single character iterators in JIT.
454    
455    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
456        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
457        codepoints that are too big for the mode are faulted, and in a UTF mode,
458        disallowed codepoints are also faulted.
459    
460    39. If PCRE was compiled with UTF support, in three places in the DFA
461        matcher there was code that should only have been obeyed in UTF mode, but
462        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
463        processing when bytes with values greater than 127 were present. In 16-bit
464        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
465        both cases the values are those that cannot be the first data item in a UTF
466        character. The three items that might have provoked this were recursions,
467        possessively repeated groups, and atomic groups.
468    
469    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
470        and pcregrep, because some OS require shared objects to be explicitly
471        passed to ld, causing the link step to fail if they are not.
472    
473    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
474        mode, patterns that started with \h* or \R* might be incorrectly matched.
475    
476    
477    Version 8.30 04-February-2012
478    -----------------------------
479    
480    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
481        name is defined in ctype.h.
482    
483    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
484        only in quite long subpatterns.
485    
486    3.  Removed the function pcre_info(), which has been obsolete and deprecated
487        since it was replaced by pcre_fullinfo() in February 2000.
488    
489    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
490        match a (*MARK), and the match failed at the start of the subject, a
491        reference to memory before the start of the subject could occur. This bug
492        was introduced by fix 17 of release 8.21.
493    
494    5.  A reference to an unset group with zero minimum repetition was giving
495        totally wrong answers (in non-JavaScript-compatibility mode). For example,
496        /(another)?(\1?)test/ matched against "hello world test". This bug was
497        introduced in release 8.13.
498    
499    6.  Add support for 16-bit character strings (a large amount of work involving
500        many changes and refactorings).
501    
502    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
503        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
504        from a file.
505    
506    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
507        rounding is not applied in this particular case).
508    
509    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
510        if they appear, or are escaped, in patterns.
511    
512    10. Get rid of a number of -Wunused-but-set-variable warnings.
513    
514    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
515        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
516        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
517        also returns the mark "x". This bug applied to capturing parentheses,
518        non-capturing parentheses, and atomic parentheses. It also applied to some
519        assertions.
520    
521    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
522        information out of configure.ac instead of relying on pcre.h.generic, which
523        is not stored in the repository.
524    
525    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
526        -lreadline.
527    
528    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
529    
530    15. Applied Graycode's patch to put the top-level frame on the stack rather
531        than the heap when not using the stack for recursion. This gives a
532        performance improvement in many cases when recursion is not deep.
533    
534    16. Experimental code added to "pcretest -C" to output the stack frame size.
535    
536    
537    Version 8.21 12-Dec-2011
538    ------------------------
539    
540    1.  Updating the JIT compiler.
541    
542    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
543        are added as well.
544    
545    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
546        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
547        calling _pcre_jit_exec. Some extra comments are added.
548    
549    4.  (*MARK) settings inside atomic groups that do not contain any capturing
550        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
551        was introduced by change 18 for 8.20.
552    
553    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
554        ECMA-262 standard.
555    
556    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
557        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
558        This bug was probably introduced by change 9 of 8.13.
559    
560    7.  While fixing 6 above, I noticed that a number of other items were being
561        incorrectly rejected as "not fixed length". This arose partly because newer
562        opcodes had not been added to the fixed-length checking code. I have (a)
563        corrected the bug and added tests for these items, and (b) arranged for an
564        error to occur if an unknown opcode is encountered while checking for fixed
565        length instead of just assuming "not fixed length". The items that were
566        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
567        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
568        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
569    
570    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
571        being incorrectly compiled and would have given unpredicatble results.
572    
573    9.  A possessively repeated subpattern with minimum repeat count greater than
574        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
575        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
576        the first (A) could occur when it should not.
577    
578    10. Add a cast and remove a redundant test from the code.
579    
580    11. JIT should use pcre_malloc/pcre_free for allocation.
581    
582    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
583        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
584        is anything other than /usr, -L is still shown).
585    
586    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
587    
588    14. Perl does not support \N without a following name in a [] class; PCRE now
589        also gives an error.
590    
591    15. If a forward reference was repeated with an upper limit of around 2000,
592        it caused the error "internal error: overran compiling workspace". The
593        maximum number of forward references (including repeats) was limited by the
594        internal workspace, and dependent on the LINK_SIZE. The code has been
595        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
596        the default depends on LINK_SIZE. There is a new upper limit (for safety)
597        of around 200,000 forward references. While doing this, I also speeded up
598        the filling in of repeated forward references.
599    
600    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
601        incorrectly expecting the subject to contain another "a" after the start.
602    
603    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
604        in the match, the SKIP should be ignored. This was not happening; instead
605        the SKIP was being treated as NOMATCH. For patterns such as
606        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
607        tested.
608    
609    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
610        now much more compatible with Perl, in particular in cases where the result
611        is a non-match for a non-anchored pattern. For example, if
612        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
613        "m", where previously it did not return a name. A side effect of this
614        change is that for partial matches, the last encountered mark name is
615        returned, as for non matches. A number of tests that were previously not
616        Perl-compatible have been moved into the Perl-compatible test files. The
617        refactoring has had the pleasing side effect of removing one argument from
618        the match() function, thus reducing its stack requirements.
619    
620    19. If the /S+ option was used in pcretest to study a pattern using JIT,
621        subsequent uses of /S (without +) incorrectly behaved like /S+.
622    
623    21. Retrieve executable code size support for the JIT compiler and fixing
624        some warnings.
625    
626    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
627        not work when the shorter character appeared right at the end of the
628        subject string.
629    
630    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
631        systems.
632    
633    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
634        output it when the /M option is used in pcretest.
635    
636    25. The CheckMan script was not being included in the distribution. Also, added
637        an explicit "perl" to run Perl scripts from the PrepareRelease script
638        because this is reportedly needed in Windows.
639    
640    26. If study data was being save in a file and studying had not found a set of
641        "starts with" bytes for the pattern, the data written to the file (though
642        never used) was taken from uninitialized memory and so caused valgrind to
643        complain.
644    
645    27. Updated RunTest.bat as provided by Sheri Pierce.
646    
647    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
648    
649    29. Computation of memory usage for the table of capturing group names was
650        giving an unnecessarily large value.
651    
652    
653    Version 8.20 21-Oct-2011
654    ------------------------
655    
656    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
657        a POSIX class. After further experiments with Perl, which convinced me that
658        Perl has bugs and confusions, a closing square bracket is no longer allowed
659        in a POSIX name. This bug also affected patterns with classes that started
660        with full stops.
661    
662    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
663        captured substring, but while checking the failing first alternative,
664        substring 1 is temporarily captured. If the output vector supplied to
665        pcre_exec() was not big enough for this capture, the yield of the function
666        was still zero ("insufficient space for captured substrings"). This cannot
667        be totally fixed without adding another stack variable, which seems a lot
668        of expense for a edge case. However, I have improved the situation in cases
669        such as /(a)(b)x|abc/ matched against "abc", where the return code
670        indicates that fewer than the maximum number of slots in the ovector have
671        been set.
672    
673    3.  Related to (2) above: when there are more back references in a pattern than
674        slots in the output vector, pcre_exec() uses temporary memory during
675        matching, and copies in the captures as far as possible afterwards. It was
676        using the entire output vector, but this conflicts with the specification
677        that only 2/3 is used for passing back captured substrings. Now it uses
678        only the first 2/3, for compatibility. This is, of course, another edge
679        case.
680    
681    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
682        main code base, and can be used by building with --enable-jit. When this is
683        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
684        runtime --no-jit option is given.
685    
686    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
687        ovector, the return from the function was zero, implying that there were
688        other matches that did not fit. The correct "exactly full" value is now
689        returned.
690    
691    6.  If a subpattern that was called recursively or as a subroutine contained
692        (*PRUNE) or any other control that caused it to give a non-standard return,
693        invalid errors such as "Error -26 (nested recursion at the same subject
694        position)" or even infinite loops could occur.
695    
696    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
697        computing the minimum length on reaching *ACCEPT, and so ended up with the
698        wrong value of 1 rather than 0. Further investigation indicates that
699        computing a minimum subject length in the presence of *ACCEPT is difficult
700        (think back references, subroutine calls), and so I have changed the code
701        so that no minimum is registered for a pattern that contains *ACCEPT.
702    
703    8.  If (*THEN) was present in the first (true) branch of a conditional group,
704        it was not handled as intended. [But see 16 below.]
705    
706    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
707        Sheri Pierce.
708    
709    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
710        the first byte in a match must be "a".
711    
712    11. Change 17 for 8.13 increased the recursion depth for patterns like
713        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
714        pattern contains any instances of (*THEN). If it does not, the old
715        optimizations are restored. It would be nice to do this on a per-group
716        basis, but at the moment that is not feasible.
717    
718    12. In some environments, the output of pcretest -C is CRLF terminated. This
719        broke RunTest's code that checks for the link size. A single white space
720        character after the value is now allowed for.
721    
722    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
723        For "fr", it uses the Windows-specific input and output files.
724    
725    14. If (*THEN) appeared in a group that was called recursively or as a
726        subroutine, it did not work as intended. [But see next item.]
727    
728    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
729        pattern fragments (but not containing any | characters). If A and B are
730        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
731        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
732        D. In other words, Perl considers parentheses that do not contain any |
733        characters to be part of a surrounding alternative, whereas PCRE was
734        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
735        differently. PCRE now behaves in the same way as Perl, except in the case
736        of subroutine/recursion calls such as (?1) which have in any case always
737        been different (but PCRE had them first :-).
738    
739    16. Related to 15 above: Perl does not treat the | in a conditional group as
740        creating alternatives. Such a group is treated in the same way as an
741        ordinary group without any | characters when processing (*THEN). PCRE has
742        been changed to match Perl's behaviour.
743    
744    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
745        RunGrepTest script failed.
746    
747    18. Change 22 for version 13 caused atomic groups to use more stack. This is
748        inevitable for groups that contain captures, but it can lead to a lot of
749        stack use in large patterns. The old behaviour has been restored for atomic
750        groups that do not contain any capturing parentheses.
751    
752    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
753        suppress the check for a minimum subject length at run time. (If it was
754        given to pcre_exec() or pcre_dfa_exec() it did work.)
755    
756    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
757        fail to work when decoding hex characters in data strings in EBCDIC
758        environments.
759    
760    21. It appears that in at least one Mac OS environment, the isxdigit() function
761        is implemented as a macro that evaluates to its argument more than once,
762        contravening the C 90 Standard (I haven't checked a later standard). There
763        was an instance in pcretest which caused it to go wrong when processing
764        \x{...} escapes in subject strings. The has been rewritten to avoid using
765        things like p++ in the argument of isxdigit().
766    
767    
768    Version 8.13 16-Aug-2011
769    ------------------------
770    
771    1.  The Unicode data tables have been updated to Unicode 6.0.0.
772    
773    2.  Two minor typos in pcre_internal.h have been fixed.
774    
775    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
776        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
777        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
778    
779    4.  There were a number of related bugs in the code for matching backrefences
780        caselessly in UTF-8 mode when codes for the characters concerned were
781        different numbers of bytes. For example, U+023A and U+2C65 are an upper
782        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
783        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
784        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
785        2-byte code at the end of the subject (it thought there wasn't enough data
786        left).
787    
788    5.  Comprehensive information about what went wrong is now returned by
789        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
790        as the output vector has at least 2 elements. The offset of the start of
791        the failing character and a reason code are placed in the vector.
792    
793    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
794        now returned is for the first byte of the failing character, instead of the
795        last byte inspected. This is an incompatible change, but I hope it is small
796        enough not to be a problem. It makes the returned offset consistent with
797        pcre_exec() and pcre_dfa_exec().
798    
799    7.  pcretest now gives a text phrase as well as the error number when
800        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
801        failure, the offset and reason code are output.
802    
803    8.  When \R was used with a maximizing quantifier it failed to skip backwards
804        over a \r\n pair if the subsequent match failed. Instead, it just skipped
805        back over a single character (\n). This seems wrong (because it treated the
806        two characters as a single entity when going forwards), conflicts with the
807        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
808        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
809        has been changed.
810    
811    9.  Some internal refactoring has changed the processing so that the handling
812        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
813        time (the PCRE_DOTALL option was changed this way some time ago: version
814        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
815        which was always a bit of a fudge. It also means that there is one less
816        argument for the match() function, which reduces its stack requirements
817        slightly. This change also fixes an incompatibility with Perl: the pattern
818        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
819    
820    10. More internal refactoring has drastically reduced the number of recursive
821        calls to match() for possessively repeated groups such as (abc)++ when
822        using pcre_exec().
823    
824    11. While implementing 10, a number of bugs in the handling of groups were
825        discovered and fixed:
826    
827        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
828        (a|)*(?1) gave a compile-time internal error.
829        ((a|)+)+  did not notice that the outer group could match an empty string.
830        (^a|^)+   was not marked as anchored.
831        (.*a|.*)+ was not marked as matching at start or after a newline.
832    
833    12. Yet more internal refactoring has removed another argument from the match()
834        function. Special calls to this function are now indicated by setting a
835        value in a variable in the "match data" data block.
836    
837    13. Be more explicit in pcre_study() instead of relying on "default" for
838        opcodes that mean there is no starting character; this means that when new
839        ones are added and accidentally left out of pcre_study(), testing should
840        pick them up.
841    
842    14. The -s option of pcretest has been documented for ages as being an old
843        synonym of -m (show memory usage). I have changed it to mean "force study
844        for every regex", that is, assume /S for every regex. This is similar to -i
845        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
846        using it. It makes it easier to run collections of tests with and without
847        study enabled, and thereby test pcre_study() more easily. All the standard
848        tests are now run with and without -s (but some patterns can be marked as
849        "never study" - see 20 below).
850    
851    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
852        restoration of the capturing data to the outer values was not happening
853        correctly.
854    
855    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
856        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
857        pattern had matched an empty string, and so incorrectly returned a no
858        match.
859    
860    17. There was optimizing code for the last branch of non-capturing parentheses,
861        and also for the obeyed branch of a conditional subexpression, which used
862        tail recursion to cut down on stack usage. Unfortunately, now that there is
863        the possibility of (*THEN) occurring in these branches, tail recursion is
864        no longer possible because the return has to be checked for (*THEN). These
865        two optimizations have therefore been removed. [But see 8.20/11 above.]
866    
867    18. If a pattern containing \R was studied, it was assumed that \R always
868        matched two bytes, thus causing the minimum subject length to be
869        incorrectly computed because \R can also match just one byte.
870    
871    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
872        was incorrectly computed.
873    
874    20. If /S is present twice on a test pattern in pcretest input, it now
875        *disables* studying, thereby overriding the use of -s on the command line
876        (see 14 above). This is necessary for one or two tests to keep the output
877        identical in both cases.
878    
879    21. When (*ACCEPT) was used in an assertion that matched an empty string and
880        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
881    
882    22. When an atomic group that contained a capturing parenthesis was
883        successfully matched, but the branch in which it appeared failed, the
884        capturing was not being forgotten if a higher numbered group was later
885        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
886        group 1 to "a", when in fact it should be unset. This applied to multi-
887        branched capturing and non-capturing groups, repeated or not, and also to
888        positive assertions (capturing in negative assertions does not happen
889        in PCRE) and also to nested atomic groups.
890    
891    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
892        subject after a captured substring, to make it easier to tell which of a
893        number of identical substrings has been captured.
894    
895    24. The way atomic groups are processed by pcre_exec() has been changed so that
896        if they are repeated, backtracking one repetition now resets captured
897        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
898        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
899        "aaa". Previously, it would have been "a". As part of this code
900        refactoring, the way recursive calls are handled has also been changed.
901    
902    25. If an assertion condition captured any substrings, they were not passed
903        back unless some other capturing happened later. For example, if
904        (?(?=(a))a) was matched against "a", no capturing was returned.
905    
906    26. When studying a pattern that contained subroutine calls or assertions,
907        the code for finding the minimum length of a possible match was handling
908        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
909        group 1 called group 2 while simultaneously a separate group 2 called group
910        1). A stack overflow occurred in this case. I have fixed this by limiting
911        the recursion depth to 10.
912    
913    27. Updated RunTest.bat in the distribution to the version supplied by Tom
914        Fortmann. This supports explicit test numbers on the command line, and has
915        argument validation and error reporting.
916    
917    28. An instance of \X with an unlimited repeat could fail if at any point the
918        first character it looked at was a mark character.
919    
920    29. Some minor code refactoring concerning Unicode properties and scripts
921        should reduce the stack requirement of match() slightly.
922    
923    30. Added the '=' option to pcretest to check the setting of unused capturing
924        slots at the end of the pattern, which are documented as being -1, but are
925        not included in the return count.
926    
927    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
928        compiled something random. Now it gives a compile-time error (as does
929        Perl).
930    
931    32. A *MARK encountered during the processing of a positive assertion is now
932        recorded and passed back (compatible with Perl).
933    
934    33. If --only-matching or --colour was set on a pcregrep call whose pattern
935        had alternative anchored branches, the search for a second match in a line
936        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
937        matched the line "0102" twice. The same bug affected patterns that started
938        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
939        twice.
940    
941    34. Previously, PCRE did not allow quantification of assertions. However, Perl
942        does, and because of capturing effects, quantifying parenthesized
943        assertions may at times be useful. Quantifiers are now allowed for
944        parenthesized assertions.
945    
946    35. A minor code tidy in pcre_compile() when checking options for \R usage.
947    
948    36. \g was being checked for fancy things in a character class, when it should
949        just be a literal "g".
950    
951    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
952        appearance of a nested POSIX class supersedes an apparent external class.
953        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
954        unescaped square brackets may also appear as part of class names. For
955        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
956        more like Perl. (But see 8.20/1 above.)
957    
958    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
959        was because it thought it was \N{name}, which is not supported).
960    
961    39. Add minix to OS list not supporting the -S option in pcretest.
962    
963    40. PCRE tries to detect cases of infinite recursion at compile time, but it
964        cannot analyze patterns in sufficient detail to catch mutual recursions
965        such as ((?1))((?2)). There is now a runtime test that gives an error if a
966        subgroup is called recursively as a subpattern for a second time at the
967        same position in the subject string. In previous releases this might have
968        been caught by the recursion limit, or it might have run out of stack.
969    
970    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
971        happen only once. PCRE was, however incorrectly giving a compile time error
972        "recursive call could loop indefinitely" because it cannot analyze the
973        pattern in sufficient detail. The compile time test no longer happens when
974        PCRE is compiling a conditional subpattern, but actual runaway loops are
975        now caught at runtime (see 40 above).
976    
977    42. It seems that Perl allows any characters other than a closing parenthesis
978        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
979        has been changed to be the same.
980    
981    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
982        as not to get warnings when autogen.sh is called. Also changed
983        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
984    
985    44. To help people who use pcregrep to scan files containing exceedingly long
986        lines, the following changes have been made:
987    
988        (a) The default value of the buffer size parameter has been increased from
989            8K to 20K. (The actual buffer used is three times this size.)
990    
991        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
992            PCRE is built.
993    
994        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
995            to be set at run time.
996    
997        (d) Numerical values in pcregrep options can be followed by K or M, for
998            example --buffer-size=50K.
999    
1000        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1001            given and the return code is set to 2.
1002    
1003    45. Add a pointer to the latest mark to the callout data block.
1004    
1005    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1006        partial match of an empty string instead of no match. This was specific to
1007        the use of ".".
1008    
1009    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1010        complete match instead of a partial match. This bug was dependent on both
1011        the PCRE_UTF8 and PCRE_DOTALL options being set.
1012    
1013    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1014        starting byte set, because \b was not being ignored.
1015    
1016    
1017    Version 8.12 15-Jan-2011
1018    ------------------------
1019    
1020    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1021        checks for such things as part of the documentation building process.
1022    
1023    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1024        --match-limit and --recursion-limit options (added for 8.11). In
1025        particular, this made one of the standard tests fail. (The integer value
1026        went into the wrong half of a long int.)
1027    
1028    3.  If the --colour option was given to pcregrep with -v (invert match), it
1029        did strange things, either producing crazy output, or crashing. It should,
1030        of course, ignore a request for colour when reporting lines that do not
1031        match.
1032    
1033    4.  Another pcregrep bug caused similar problems if --colour was specified with
1034        -M (multiline) and the pattern match finished with a line ending.
1035    
1036    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1037        matched in multiline mode, the following line was shown as part of the
1038        match. This seems wrong, so I have changed it.
1039    
1040    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1041        the check for further matches in the same line (so they could be coloured)
1042        to overrun the end of the current line. If another match was found, it was
1043        incorrectly shown (and then shown again when found in the next line).
1044    
1045    7.  If pcregrep was compiled under Windows, there was a reference to the
1046        function pcregrep_exit() before it was defined. I am assuming this was
1047        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1048        reported by a user. I've moved the definition above the reference.
1049    
1050    
1051    Version 8.11 10-Dec-2010
1052    ------------------------
1053    
1054    1.  (*THEN) was not working properly if there were untried alternatives prior
1055        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1056        backtracked to try for "b" instead of moving to the next alternative branch
1057        at the same level (in this case, to look for "c"). The Perl documentation
1058        is clear that when (*THEN) is backtracked onto, it goes to the "next
1059        alternative in the innermost enclosing group".
1060    
1061    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1062        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1063        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1064        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1065        (*THEN).
1066    
1067    3.  If \s appeared in a character class, it removed the VT character from
1068        the class, even if it had been included by some previous item, for example
1069        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1070        of \s, but is part of the POSIX "space" class.)
1071    
1072    4.  A partial match never returns an empty string (because you can always
1073        match an empty string at the end of the subject); however the checking for
1074        an empty string was starting at the "start of match" point. This has been
1075        changed to the "earliest inspected character" point, because the returned
1076        data for a partial match starts at this character. This means that, for
1077        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1078        (previously it gave "no match").
1079    
1080    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1081        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1082        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1083        has an implication that the given string is incomplete (because a partial
1084        match is preferred over a full match). For this reason, these items now
1085        give a partial match in this situation. [Aside: previously, the one case
1086        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1087        match rather than a full match, which was wrong by the old rules, but is
1088        now correct.]
1089    
1090    6.  There was a bug in the handling of #-introduced comments, recognized when
1091        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1092        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1093        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1094        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1095        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1096        places in pcre_compile().
1097    
1098    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1099        comments when looking ahead for named forward references to subpatterns,
1100        the only newline sequence it recognized was NL. It now handles newlines
1101        according to the set newline convention.
1102    
1103    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1104        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1105        cater for a lack of strerror(). These oversights have been fixed.
1106    
1107    9.  Added --match-limit and --recursion-limit to pcregrep.
1108    
1109    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1110    
1111    11. When the -o option was used, pcregrep was setting a return code of 1, even
1112        when matches were found, and --line-buffered was not being honoured.
1113    
1114    12. Added an optional parentheses number to the -o and --only-matching options
1115        of pcregrep.
1116    
1117    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1118        can match an empty string. The code to do it in pcretest and pcredemo
1119        needed fixing:
1120    
1121        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1122            only one byte after an empty string match just before CRLF (this case
1123            just got forgotten; "any" and "anycrlf" were OK).
1124    
1125        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1126            mode when an empty string match preceded an ASCII character followed by
1127            a non-ASCII character. (The code for advancing by one character rather
1128            than one byte was nonsense.)
1129    
1130        (c) The pcredemo.c sample program did not have any code at all to handle
1131            the cases when CRLF is a valid newline sequence.
1132    
1133    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1134        as a starting offset was within the subject string. There is now a new
1135        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1136        negative or greater than the length of the string. In order to test this,
1137        pcretest is extended to allow the setting of negative starting offsets.
1138    
1139    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1140        starting offset points to the beginning of a UTF-8 character was
1141        unnecessarily clumsy. I tidied it up.
1142    
1143    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1144        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1145    
1146    17. Nobody had reported that the --include_dir option, which was added in
1147        release 7.7 should have been called --include-dir (hyphen, not underscore)
1148        for compatibility with GNU grep. I have changed it to --include-dir, but
1149        left --include_dir as an undocumented synonym, and the same for
1150        --exclude-dir, though that is not available in GNU grep, at least as of
1151        release 2.5.4.
1152    
1153    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1154        characters from a string of bytes) have been redefined so as not to use
1155        loops, in order to improve performance in some environments. At the same
1156        time, I abstracted some of the common code into auxiliary macros to save
1157        repetition (this should not affect the compiled code).
1158    
1159    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1160        compile-time error is now given if \c is not followed by an ASCII
1161        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1162        different, and any byte value is allowed.)
1163    
1164    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1165        START_OPTIMIZE option, which is now allowed at compile time - but just
1166        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1167        to pcregrep and other applications that have no direct access to PCRE
1168        options. The new /Y option in pcretest sets this option when calling
1169        pcre_compile().
1170    
1171    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1172        back references. Groups containing recursive back references were forced to
1173        be atomic by that change, but in the case of named groups, the amount of
1174        memory required was incorrectly computed, leading to "Failed: internal
1175        error: code overflow". This has been fixed.
1176    
1177    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1178        pcretest.c, to avoid build problems in some Borland environments.
1179    
1180    
1181    Version 8.10 25-Jun-2010
1182    ------------------------
1183    
1184    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1185        THEN.
1186    
1187    2.  (*ACCEPT) was not working when inside an atomic group.
1188    
1189    3.  Inside a character class, \B is treated as a literal by default, but
1190        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1191        causes the error). The code is unchanged, but I tidied the documentation.
1192    
1193    4.  Inside a character class, PCRE always treated \R and \X as literals,
1194        whereas Perl faults them if its -w option is set. I have changed PCRE so
1195        that it faults them when PCRE_EXTRA is set.
1196    
1197    5.  Added support for \N, which always matches any character other than
1198        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1199    
1200    6.  When compiling pcregrep with newer versions of gcc which may have
1201        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1202        declared with attribute warn_unused_result" were given. Just casting the
1203        result to (void) does not stop the warnings; a more elaborate fudge is
1204        needed. I've used a macro to implement this.
1205    
1206    7.  Minor change to pcretest.c to avoid a compiler warning.
1207    
1208    8.  Added four artifical Unicode properties to help with an option to make
1209        \s etc use properties (see next item). The new properties are: Xan
1210        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1211    
1212    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1213        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1214        this option. Modified pcretest to add /W to test this facility. Added
1215        REG_UCP to make it available via the POSIX interface.
1216    
1217    10. Added --line-buffered to pcregrep.
1218    
1219    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1220        studied, and the match started with a letter with a code point greater than
1221        127 whose first byte was different to the first byte of the other case of
1222        the letter, the other case of this starting letter was not recognized
1223        (#976).
1224    
1225    12. If a pattern that was studied started with a repeated Unicode property
1226        test, for example, \p{Nd}+, there was the theoretical possibility of
1227        setting up an incorrect bitmap of starting bytes, but fortunately it could
1228        not have actually happened in practice until change 8 above was made (it
1229        added property types that matched character-matching opcodes).
1230    
1231    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1232        possible starting bytes for non-anchored patterns.
1233    
1234    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1235        \R, and also a number of cases that involve Unicode properties, both
1236        explicit and implicit when PCRE_UCP is set.
1237    
1238    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1239        input, it could crash or give wrong results if characters with values
1240        greater than 0xc0 were present in the subject string. (Detail: it assumed
1241        UTF-8 input when processing these items.)
1242    
1243    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1244        size_t is 64-bit (#991).
1245    
1246    17. Added a check for running out of memory when PCRE is compiled with
1247        --disable-stack-for-recursion (#990).
1248    
1249    18. If the last data line in a file for pcretest does not have a newline on
1250        the end, a newline was missing in the output.
1251    
1252    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1253        less than 128) in its various bitmaps. However, there is a facility for
1254        generating tables according to the current locale when PCRE is compiled. It
1255        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1256        characters, are recognized by isspace() and therefore were getting set in
1257        these tables, and indeed these tables seem to approximate to ISO 8859. This
1258        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1259        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1260        which of course cannot start UTF-8 characters. I have changed the code so
1261        that only real ASCII characters (less than 128) and the correct starting
1262        bytes for UTF-8 encodings are set for characters greater than 127 when in
1263        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1264        altogether.)
1265    
1266    20. Added the /T option to pcretest so as to be able to run tests with non-
1267        standard character tables, thus making it possible to include the tests
1268        used for 19 above in the standard set of tests.
1269    
1270    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1271        reference to a subpattern the other side of a comment that contains an
1272        opening parenthesis caused either an internal compiling error, or a
1273        reference to the wrong subpattern.
1274    
1275    
1276    Version 8.02 19-Mar-2010
1277    ------------------------
1278    
1279    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1280    
1281    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1282        configured.
1283    
1284    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1285        original author of that file, following a query about its status.
1286    
1287    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1288        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1289    
1290    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1291        quantifier applied to a forward-referencing subroutine call, could compile
1292        incorrect code or give the error "internal error: previously-checked
1293        referenced subpattern not found".
1294    
1295    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1296        variables to point to external functions. For these systems, therefore,
1297        pcre_malloc etc. are now initialized to local functions that call the
1298        relevant global functions.
1299    
1300    7.  There were two entries missing in the vectors called coptable and poptable
1301        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1302        I've fixed the data, and added a kludgy way of testing at compile time that
1303        the lengths are correct (equal to the number of opcodes).
1304    
1305    8.  Following on from 7, I added a similar kludge to check the length of the
1306        eint vector in pcreposix.c.
1307    
1308    9.  Error texts for pcre_compile() are held as one long string to avoid too
1309        much relocation at load time. To find a text, the string is searched,
1310        counting zeros. There was no check for running off the end of the string,
1311        which could happen if a new error number was added without updating the
1312        string.
1313    
1314    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1315    
1316    11. \K was not working if it appeared in an atomic group or in a group that
1317        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1318        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1319        the assertion is positive, but not if it is negative.
1320    
1321    12. Change 11 fortuitously reduced the size of the stack frame used in the
1322        "match()" function of pcre_exec.c by one pointer. Forthcoming
1323        implementation of support for (*MARK) will need an extra pointer on the
1324        stack; I have reserved it now, so that the stack frame size does not
1325        decrease.
1326    
1327    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1328        item in branch that calls a recursion is a subroutine call - as in the
1329        second branch in the above example - was incorrectly given the compile-
1330        time error "recursive call could loop indefinitely" because pcre_compile()
1331        was not correctly checking the subroutine for matching a non-empty string.
1332    
1333    14. The checks for overrunning compiling workspace could trigger after an
1334        overrun had occurred. This is a "should never occur" error, but it can be
1335        triggered by pathological patterns such as hundreds of nested parentheses.
1336        The checks now trigger 100 bytes before the end of the workspace.
1337    
1338    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1339    
1340    
1341    Version 8.01 19-Jan-2010
1342    ------------------------
1343    
1344    1.  If a pattern contained a conditional subpattern with only one branch (in
1345        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1346        computed the wrong minimum data length (which is of course zero for such
1347        subpatterns). This could cause incorrect "no match" results.
1348    
1349    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1350        the pattern is reset in the first branch, pcre_compile() failed with
1351        "internal error: code overflow at offset...". This happened only when
1352        the reset was to the original external option setting. (An optimization
1353        abstracts leading options settings into an external setting, which was the
1354        cause of this.)
1355    
1356    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1357        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1358        assertion pattern did not match (meaning that the assertion was true), it
1359        was incorrectly treated as false if the SKIP had been reached during the
1360        matching. This also applied to assertions used as conditions.
1361    
1362    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1363        assertion subpattern, including such a pattern used as a condition,
1364        unpredictable results occurred, instead of the error return
1365        PCRE_ERROR_DFA_UITEM.
1366    
1367    5.  The C++ GlobalReplace function was not working like Perl for the special
1368        situation when an empty string is matched. It now does the fancy magic
1369        stuff that is necessary.
1370    
1371    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1372        removed. (These were left over from very, very early versions of PCRE.)
1373    
1374    7.  Some cosmetic changes to the code to make life easier when compiling it
1375        as part of something else:
1376    
1377        (a) Change DEBUG to PCRE_DEBUG.
1378    
1379        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1380            called "current" as "current_branch", to prevent a collision with the
1381            Linux macro when compiled as a kernel module.
1382    
1383        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1384            prevent a collision with the Linux macro when compiled as a kernel
1385            module.
1386    
1387    8.  In pcre_compile() there are some checks for integer overflows that used to
1388        cast potentially large values to (double). This has been changed to that
1389        when building, a check for int64_t is made, and if it is found, it is used
1390        instead, thus avoiding the use of floating point arithmetic. (There is no
1391        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1392        double.
1393    
1394    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1395        2005 (difference between two addresses compared to an unsigned value).
1396    
1397    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1398        custom one, because of the following reported problem in Windows:
1399    
1400          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1401              under Win32.
1402          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1403              therefore missing the function definition.
1404          - The compiler thus generates a "C" signature for the test function.
1405          - The linker fails to find the "C" function.
1406          - PCRE fails to configure if asked to do so against libbz2.
1407    
1408    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1409        messages were output:
1410    
1411          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1412          rerunning libtoolize, to keep the correct libtool macros in-tree.
1413          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1414    
1415        I have done both of these things.
1416    
1417    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1418        most of the time, it *can* run out if it is given a pattern that contains a
1419        runaway infinite recursion. I updated the discussion in the pcrestack man
1420        page.
1421    
1422    13. Now that we have gone to the x.xx style of version numbers, the minor
1423        version may start with zero. Using 08 or 09 is a bad idea because users
1424        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1425        interpreted as invalid octal numbers. I've updated the previous comment in
1426        configure.ac, and also added a check that gives an error if 08 or 09 are
1427        used.
1428    
1429    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1430        causing partial matching to fail when the end of the subject matched \W
1431        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1432    
1433    15. There were some discrepancies between the declarations in pcre_internal.h
1434        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1435        their definitions. The declarations used "const uschar *" and the
1436        definitions used USPTR. Even though USPTR is normally defined as "const
1437        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1438        reported that: "This difference in casting confuses some C++ compilers, for
1439        example, SunCC recognizes above declarations as different functions and
1440        generates broken code for hbpcre." I have changed the declarations to use
1441        USPTR.
1442    
1443    16. GNU libtool is named differently on some systems. The autogen.sh script now
1444        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1445        (FreeBSD).
1446    
1447    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1448        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1449        comment: "Figure out how to create a longlong from a string: strtoll and
1450        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1451        instance, but it only takes 2 args instead of 3!"
1452    
1453    18. A subtle bug concerned with back references has been fixed by a change of
1454        specification, with a corresponding code fix. A pattern such as
1455        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1456        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1457        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1458        same bug. Such groups have to be quantified to be useful, or contained
1459        inside another quantified group. (If there's no repetition, the reference
1460        can never match.) The problem arises because, having left the group and
1461        moved on to the rest of the pattern, a later failure that backtracks into
1462        the group uses the captured value from the final iteration of the group
1463        rather than the correct earlier one. I have fixed this in PCRE by forcing
1464        any group that contains a reference to itself to be an atomic group; that
1465        is, there cannot be any backtracking into it once it has completed. This is
1466        similar to recursive and subroutine calls.
1467    
1468    
1469    Version 8.00 19-Oct-09
1470    ----------------------
1471    
1472    1.  The table for translating pcre_compile() error codes into POSIX error codes
1473        was out-of-date, and there was no check on the pcre_compile() error code
1474        being within the table. This could lead to an OK return being given in
1475        error.
1476    
1477    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1478        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1479        in a Windows environment.
1480    
1481    3.  The pcregrep --count option prints the count for each file even when it is
1482        zero, as does GNU grep. However, pcregrep was also printing all files when
1483        --files-with-matches was added. Now, when both options are given, it prints
1484        counts only for those files that have at least one match. (GNU grep just
1485        prints the file name in this circumstance, but including the count seems
1486        more useful - otherwise, why use --count?) Also ensured that the
1487        combination -clh just lists non-zero counts, with no names.
1488    
1489    4.  The long form of the pcregrep -F option was incorrectly implemented as
1490        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1491        but it seems right to fix it, and I didn't think it was worth preserving
1492        the old behaviour.
1493    
1494    5.  The command line items --regex=pattern and --regexp=pattern were not
1495        recognized by pcregrep, which required --regex pattern or --regexp pattern
1496        (with a space rather than an '='). The man page documented the '=' forms,
1497        which are compatible with GNU grep; these now work.
1498    
1499    6.  No libpcreposix.pc file was created for pkg-config; there was just
1500        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1501    
1502    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1503        when UCP support is not needed, by modifying the Python script that
1504        generates it from Unicode data files. This should not matter if the module
1505        is correctly used as a library, but I received one complaint about 50K of
1506        unwanted data. My guess is that the person linked everything into his
1507        program rather than using a library. Anyway, it does no harm.
1508    
1509    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1510        was a minimum greater than 1 for a wide character in a possessive
1511        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1512        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1513        character. Chaos in the form of incorrect output or a compiling loop could
1514        result.
1515    
1516    9.  The restrictions on what a pattern can contain when partial matching is
1517        requested for pcre_exec() have been removed. All patterns can now be
1518        partially matched by this function. In addition, if there are at least two
1519        slots in the offset vector, the offset of the earliest inspected character
1520        for the match and the offset of the end of the subject are set in them when
1521        PCRE_ERROR_PARTIAL is returned.
1522    
1523    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1524        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1525        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1526        and may be more useful for multi-segment matching.
1527    
1528    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1529        used to be given if ever the end of the subject was reached; now it is
1530        given only if matching could not proceed because another character was
1531        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1532        string "Z", which now yields "no match" instead of "partial match". In the
1533        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1534        final character ended with (*FAIL).
1535    
1536    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1537        if the pattern had a "must contain" character that was already found in the
1538        earlier partial match, unless partial matching was again requested. For
1539        example, with the pattern /dog.(body)?/, the "must contain" character is
1540        "g". If the first part-match was for the string "dog", restarting with
1541        "sbody" failed. This bug has been fixed.
1542    
1543    13. The string returned by pcre_dfa_exec() after a partial match has been
1544        changed so that it starts at the first inspected character rather than the
1545        first character of the match. This makes a difference only if the pattern
1546        starts with a lookbehind assertion or \b or \B (\K is not supported by
1547        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1548        matching functions compatible, and I think it's the right thing to do.
1549    
1550    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1551        so that the demonstration program is easily available in environments where
1552        PCRE has not been installed from source.
1553    
1554    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1555        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1556        library.
1557    
1558    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1559        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1560        is not the first non-POSIX option to be added. Clearly some people find
1561        these options useful.
1562    
1563    17. If a caller to the POSIX matching function regexec() passes a non-zero
1564        value for nmatch with a NULL value for pmatch, the value of
1565        nmatch is forced to zero.
1566    
1567    18. RunGrepTest did not have a test for the availability of the -u option of
1568        the diff command, as RunTest does. It now checks in the same way as
1569        RunTest, and also checks for the -b option.
1570    
1571    19. If an odd number of negated classes containing just a single character
1572        interposed, within parentheses, between a forward reference to a named
1573        subpattern and the definition of the subpattern, compilation crashed with
1574        an internal error, complaining that it could not find the referenced
1575        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1576        [The bug was that it was starting one character too far in when skipping
1577        over the character class, thus treating the ] as data rather than
1578        terminating the class. This meant it could skip too much.]
1579    
1580    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1581        /g option in pcretest when the pattern contains \K, which makes it possible
1582        to have an empty string match not at the start, even when the pattern is
1583        anchored. Updated pcretest and pcredemo to use this option.
1584    
1585    21. If the maximum number of capturing subpatterns in a recursion was greater
1586        than the maximum at the outer level, the higher number was returned, but
1587        with unset values at the outer level. The correct (outer level) value is
1588        now given.
1589    
1590    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1591        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1592        make it do so. The string so far is captured, making this feature
1593        compatible with Perl.
1594    
1595    23. The tests have been re-organized, adding tests 11 and 12, to make it
1596        possible to check the Perl 5.10 features against Perl 5.10.
1597    
1598    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1599        pattern matches a fixed length string. PCRE did not allow this; now it
1600        does. Neither allows recursion.
1601    
1602    25. I finally figured out how to implement a request to provide the minimum
1603        length of subject string that was needed in order to match a given pattern.
1604        (It was back references and recursion that I had previously got hung up
1605        on.) This code has now been added to pcre_study(); it finds a lower bound
1606        to the length of subject needed. It is not necessarily the greatest lower
1607        bound, but using it to avoid searching strings that are too short does give
1608        some useful speed-ups. The value is available to calling programs via
1609        pcre_fullinfo().
1610    
1611    26. While implementing 25, I discovered to my embarrassment that pcretest had
1612        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1613        study optimizations had never been tested with that matching function.
1614        Oops. What is worse, even when it was passed study data, there was a bug in
1615        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1616        were also very few tests of studied patterns with pcre_dfa_exec().
1617    
1618    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1619        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1620        on the other side of the coin, they are no longer allowed to have different
1621        names, because these cannot be distinguished in PCRE, and this has caused
1622        confusion. (This is a difference from Perl.)
1623    
1624    28. When duplicate subpattern names are present (necessarily with different
1625        numbers, as required by 27 above), and a test is made by name in a
1626        conditional pattern, either for a subpattern having been matched, or for
1627        recursion in such a pattern, all the associated numbered subpatterns are
1628        tested, and the overall condition is true if the condition is true for any
1629        one of them. This is the way Perl works, and is also more like the way
1630        testing by number works.
1631    
1632    
1633    Version 7.9 11-Apr-09
1634    ---------------------
1635    
1636    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1637        (pcretest), all targets were linked against these libraries. This included
1638        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1639        libraries. This caused unwanted dependencies to be created. This problem
1640        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1641        pcretest is linked with readline.
1642    
1643    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1644        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1645        moved outside it again, because FALSE and TRUE are already defined in AIX,
1646        but BOOL is not.
1647    
1648    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1649        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1650    
1651    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1652        hyphens) following file names and line numbers when outputting matching
1653        lines. This is not true; no spaces are inserted. I have also clarified the
1654        wording for the --colour (or --color) option.
1655    
1656    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1657        was not coloured; this is different to GNU grep, so I have changed it to be
1658        the same.
1659    
1660    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1661        each matching line was coloured. Now it goes on to look for further matches
1662        of any of the test patterns, which is the same behaviour as GNU grep.
1663    
1664    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1665        doesn't make sense to accept an empty string match in pcregrep, so I have
1666        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1667        seems to be how GNU grep behaves. [But see later change 40 for release
1668        8.33.]
1669    
1670    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1671        start or after a newline", because the conditional assertion was not being
1672        correctly handled. The rule now is that both the assertion and what follows
1673        in the first alternative must satisfy the test.
1674    
1675    9.  If auto-callout was enabled in a pattern with a conditional group whose
1676        condition was an assertion, PCRE could crash during matching, both with
1677        pcre_exec() and pcre_dfa_exec().
1678    
1679    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1680        used for matching.
1681    
1682    11. Unicode property support in character classes was not working for
1683        characters (bytes) greater than 127 when not in UTF-8 mode.
1684    
1685    12. Added the -M command line option to pcretest.
1686    
1687    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1688    
1689    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1690    
1691    16. Added comments and documentation about mis-use of no_arg in the C++
1692        wrapper.
1693    
1694    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1695        from Martin Jerabek that uses macro names for all relevant character and
1696        string constants.
1697    
1698    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1699        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1700        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1701        these, but not everybody uses configure.
1702    
1703    19. A conditional group that had only one branch was not being correctly
1704        recognized as an item that could match an empty string. This meant that an
1705        enclosing group might also not be so recognized, causing infinite looping
1706        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1707        with the subject "ab", where knowledge that the repeated group can match
1708        nothing is needed in order to break the loop.
1709    
1710    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1711        exec(), but without supplying a callout function, matching went wrong.
1712    
1713    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1714        leak if the size of the offset vector was greater than 30. When the vector
1715        is smaller, the saved offsets during recursion go onto a local stack
1716        vector, but for larger vectors malloc() is used. It was failing to free
1717        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1718        error, in fact).
1719    
1720    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1721        heapframe that is used only when UTF-8 support is enabled. This caused no
1722        problem, but was untidy.
1723    
1724    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1725        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1726        included within another project.
1727    
1728    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1729        slightly modified by me:
1730    
1731          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1732              not building pcregrep.
1733    
1734          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1735              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1736    
1737    25. Forward references, both numeric and by name, in patterns that made use of
1738        duplicate group numbers, could behave incorrectly or give incorrect errors,
1739        because when scanning forward to find the reference group, PCRE was not
1740        taking into account the duplicate group numbers. A pattern such as
1741        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1742    
1743    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1744        the feature of a custom pointer more persuasive (as requested by a user).
1745    
1746    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1747        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1748        pre-defined.
1749    
1750    28. Added support for (*UTF8) at the start of a pattern.
1751    
1752    29. Arrange for flags added by the "release type" setting in CMake to be shown
1753        in the configuration summary.
1754    
1755    
1756    Version 7.8 05-Sep-08
1757    ---------------------
1758    
1759    1.  Replaced UCP searching code with optimized version as implemented for Ad
1760        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1761        stage table and inline lookup instead of a function, giving speed ups of 2
1762        to 5 times on some simple patterns that I tested. Permission was given to
1763        distribute the MultiStage2.py script that generates the tables (it's not in
1764        the tarball, but is in the Subversion repository).
1765    
1766    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1767        scripts.
1768    
1769    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1770        a group with a zero qualifier. The result of the study could be incorrect,
1771        or the function might crash, depending on the pattern.
1772    
1773    4.  Caseless matching was not working for non-ASCII characters in back
1774        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1775        It now works when Unicode Property Support is available.
1776    
1777    5.  In pcretest, an escape such as \x{de} in the data was always generating
1778        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1779        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1780        truncation.
1781    
1782    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1783    
1784    7.  Added two (int) casts to pcregrep when printing the difference of two
1785        pointers, in case they are 64-bit values.
1786    
1787    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1788        test 2 if it fails.
1789    
1790    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1791        and a #define of that name to empty if it is not externally set. This is to
1792        allow users of MSVC to set it if necessary.
1793    
1794    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1795        the convenience functions in the pcre_get.c source file.
1796    
1797    11. An option change at the start of a pattern that had top-level alternatives
1798        could cause overwriting and/or a crash. This command provoked a crash in
1799        some environments:
1800    
1801          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1802    
1803        This potential security problem was recorded as CVE-2008-2371.
1804    
1805    12. For a pattern where the match had to start at the beginning or immediately
1806        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1807        pcre_dfa_exec() could read past the end of the passed subject if there was
1808        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1809        pcretest so that it places the subject at the end of its malloc-ed buffer.
1810    
1811    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1812        exec() might read past the end of the data buffer in UTF-8 mode.
1813    
1814    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1815        the data contained the byte 0x85 as part of a UTF-8 character within its
1816        first line. This applied both to normal and DFA matching.
1817    
1818    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1819        /^[^d]*?$/8 failed to match "abc".
1820    
1821    16. Added a missing copyright notice to pcrecpp_internal.h.
1822    
1823    17. Make it more clear in the documentation that values returned from
1824        pcre_exec() in ovector are byte offsets, not character counts.
1825    
1826    18. Tidied a few places to stop certain compilers from issuing warnings.
1827    
1828    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1829        supplied by Stefan Weber. I made a further small update for 7.8 because
1830        there is a change of source arrangements: the pcre_searchfuncs.c module is
1831        replaced by pcre_ucd.c.
1832    
1833    
1834    Version 7.7 07-May-08
1835    ---------------------
1836    
1837    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1838        a string to a long long, pretend we don't even have a long long." This is
1839        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1840    
1841    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1842        pre-7.6 versions, which defined a global no_arg variable instead of putting
1843        it in the RE class. (See also #8 below.)
1844    
1845    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1846        Lopes.
1847    
1848    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1849    
1850        (1) The include/exclude patterns were being applied to the whole pathnames
1851            of files, instead of just to the final components.
1852    
1853        (2) If there was more than one level of directory, the subdirectories were
1854            skipped unless they satisfied the include/exclude conditions. This is
1855            inconsistent with GNU grep (and could even be seen as contrary to the
1856            pcregrep specification - which I improved to make it absolutely clear).
1857            The action now is always to scan all levels of directory, and just
1858            apply the include/exclude patterns to regular files.
1859    
1860    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1861        --exclude_dir in the tests to avoid scanning .svn directories.
1862    
1863    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1864        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1865        doesn't support NULs in patterns.
1866    
1867    7.  Added some missing "const"s to declarations of static tables in
1868        pcre_compile.c and pcre_dfa_exec.c.
1869    
1870    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1871        caused by fix #2  above. (Subsequently also a second patch to fix the
1872        first patch. And a third patch - this was a messy problem.)
1873    
1874    9.  Applied Craig's patch to remove the use of push_back().
1875    
1876    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1877        matching function regexec().
1878    
1879    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1880        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1881        references. PCRE supports relative numbers with this syntax (I don't think
1882        Oniguruma does).
1883    
1884    12. Previously, a group with a zero repeat such as (...){0} was completely
1885        omitted from the compiled regex. However, this means that if the group
1886        was called as a subroutine from elsewhere in the pattern, things went wrong
1887        (an internal error was given). Such groups are now left in the compiled
1888        pattern, with a new opcode that causes them to be skipped at execution
1889        time.
1890    
1891    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1892        to the way PCRE behaves:
1893    
1894        (a) A lone ] character is dis-allowed (Perl treats it as data).
1895    
1896        (b) A back reference to an unmatched subpattern matches an empty string
1897            (Perl fails the current match path).
1898    
1899        (c) A data ] in a character class must be notated as \] because if the
1900            first data character in a class is ], it defines an empty class. (In
1901            Perl it is not possible to have an empty class.) The empty class []
1902            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1903            The negative empty class [^] matches any one character, independently
1904            of the DOTALL setting.
1905    
1906    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1907        non-existent subpattern following a character class starting with ']' and
1908        containing () gave an internal compiling error instead of "reference to
1909        non-existent subpattern". Fortunately, when the pattern did exist, the
1910        compiled code was correct. (When scanning forwards to check for the
1911        existence of the subpattern, it was treating the data ']' as terminating
1912        the class, so got the count wrong. When actually compiling, the reference
1913        was subsequently set up correctly.)
1914    
1915    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1916        it was being rejected as not supported by pcre_dfa_exec(), even though
1917        other assertions are supported. I have made pcre_dfa_exec() support
1918        (*FAIL).
1919    
1920    16. The implementation of 13c above involved the invention of a new opcode,
1921        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1922        cannot be changed at match time, I realized I could make a small
1923        improvement to matching performance by compiling OP_ALLANY instead of
1924        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1925        on the OP_ANY path.
1926    
1927    17. Compiling pcretest on Windows with readline support failed without the
1928        following two fixes: (1) Make the unistd.h include conditional on
1929        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1930    
1931    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1932        ncurses library to be included for pcretest when ReadLine support is
1933        requested, but also to allow for it to be overridden. This patch came from
1934        Daniel Bergström.
1935    
1936    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1937        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1938        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1939        spotting this.
1940    
1941    
1942    Version 7.6 28-Jan-08
1943    ---------------------
1944    
1945    1.  A character class containing a very large number of characters with
1946        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1947        overflow.
1948    
1949    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1950        HAVE_LONG_LONG is not defined.
1951    
1952    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1953        bring them up to date and include new features. This patch includes:
1954    
1955        - Fixed PH's badly added libz and libbz2 support.
1956        - Fixed a problem with static linking.
1957        - Added pcredemo. [But later removed - see 7 below.]
1958        - Fixed dftables problem and added an option.
1959        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1960            HAVE_LONG_LONG.
1961        - Added readline support for pcretest.
1962        - Added an listing of the option settings after cmake has run.
1963    
1964    4.  A user submitted a patch to Makefile that makes it easy to create
1965        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1966        Makefile.am that cause it to include this special target, without
1967        affecting anything else. Note that the same mingw target plus all
1968        the other distribution libraries and programs are now supported
1969        when configuring with CMake (see 6 below) instead of with
1970        Configure/Make.
1971    
1972    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1973        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1974        exported in the Windows port". It has not yet been confirmed that the patch
1975        solves the problem, but it does no harm.
1976    
1977    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1978        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1979        with CMake, and also correct the comment about stack recursion.
1980    
1981    7.  Remove the automatic building of pcredemo from the ./configure system and
1982        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1983        of a program that users should build themselves after PCRE is installed, so
1984        building it automatically is not really right. What is more, it gave
1985        trouble in some build environments.
1986    
1987    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1988    
1989    
1990    Version 7.5 10-Jan-08
1991  ---------------------  ---------------------
1992    
1993  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1994      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1995    
1996  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1997      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1998      included.      included.
1999    
2000  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
2001      [:^space:].      [:^space:].
2002    
2003  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2004      defined or documented. It seems to have been a typo for PCRE_STATIC, so      defined or documented. It seems to have been a typo for PCRE_STATIC, so
2005      I have changed it.      I have changed it.
2006    
2007  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
2008      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
2009      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
2010      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
2011      expected" is now given for (?&) (a zero-length name), and this patch also      expected" is now given for (?&) (a zero-length name), and this patch also
2012      makes it give the same error for \k'' (previously it complained that that      makes it give the same error for \k'' (previously it complained that that
2013      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
2014    
2015  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
2016      this is right because (?- can be followed by option settings as well as by      this is right because (?- can be followed by option settings as well as by
2017      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
2018    
2019  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2020      than the number used in the conditional) now cause a compile-time error.      than the number used in the conditional) now cause a compile-time error.
2021      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
2022      treats the conditional as always being FALSE (as PCRE used to), but it      treats the conditional as always being FALSE (as PCRE used to), but it
2023      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
2024    
2025  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
2026      and messages.      and messages.
2027    
2028  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
2029      "backspace".      "backspace".
2030    
2031  10. Remove two redundant lines of code that can never be obeyed (their function  10. Remove two redundant lines of code that can never be obeyed (their function
2032      was moved elsewhere).      was moved elsewhere).
2033    
2034  11. The program that makes PCRE's Unicode character property table had a bug  11. The program that makes PCRE's Unicode character property table had a bug
2035      which caused it to generate incorrect table entries for sequences of      which caused it to generate incorrect table entries for sequences of
2036      characters that have the same character type, but are in different scripts.      characters that have the same character type, but are in different scripts.
2037      It amalgamated them into a single range, with the script of the first of      It amalgamated them into a single range, with the script of the first of
2038      them. In other words, some characters were in the wrong script. There were      them. In other words, some characters were in the wrong script. There were
2039      thirteen such cases, affecting characters in the following ranges:      thirteen such cases, affecting characters in the following ranges:
2040    
2041        U+002b0 - U+002c1        U+002b0 - U+002c1
2042        U+0060c - U+0060d        U+0060c - U+0060d
2043        U+0061e - U+00612        U+0061e - U+00612
2044        U+0064b - U+0065e        U+0064b - U+0065e
2045        U+0074d - U+0076d        U+0074d - U+0076d
2046        U+01800 - U+01805        U+01800 - U+01805
# Line 66  Version 7.5 12-Nov-07 Line 2052  Version 7.5 12-Nov-07
2052        U+0fb46 - U+0fbb1        U+0fb46 - U+0fbb1
2053        U+10450 - U+1049d        U+10450 - U+1049d
2054    
2055    12. The -o option (show only the matching part of a line) for pcregrep was not
2056        compatible with GNU grep in that, if there was more than one match in a
2057        line, it showed only the first of them. It now behaves in the same way as
2058        GNU grep.
2059    
2060    13. If the -o and -v options were combined for pcregrep, it printed a blank
2061        line for every non-matching line. GNU grep prints nothing, and pcregrep now
2062        does the same. The return code can be used to tell if there were any
2063        non-matching lines.
2064    
2065    14. Added --file-offsets and --line-offsets to pcregrep.
2066    
2067    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2068        infinitely looping recursion. The bug was that positive lookaheads were not
2069        being skipped when checking for a possible empty match (negative lookaheads
2070        and both kinds of lookbehind were skipped).
2071    
2072    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2073        inclusion of <windows.h> to before rather than after the definition of
2074        INVALID_FILE_ATTRIBUTES (patch from David Byron).
2075    
2076    17. Specifying a possessive quantifier with a specific limit for a Unicode
2077        character property caused pcre_compile() to compile bad code, which led at
2078        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2079        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2080        caused the error; without that there was no problem.
2081    
2082    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2083    
2084    19. Added --enable-pcretest-libreadline.
2085    
2086    20. In pcrecpp.cc, the variable 'count' was incremented twice in
2087        RE::GlobalReplace(). As a result, the number of replacements returned was
2088        double what it should be. I removed one of the increments, but Craig sent a
2089        later patch that removed the other one (the right fix) and added unit tests
2090        that check the return values (which was not done before).
2091    
2092    21. Several CMake things:
2093    
2094        (1) Arranged that, when cmake is used on Unix, the libraries end up with
2095            the names libpcre and libpcreposix, not just pcre and pcreposix.
2096    
2097        (2) The above change means that pcretest and pcregrep are now correctly
2098            linked with the newly-built libraries, not previously installed ones.
2099    
2100        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2101    
2102    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2103        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2104        UTF-8 newline character). The key issue is that the pattern starts .*;
2105        this means that the match must be either at the beginning, or after a
2106        newline. The bug was in the code for advancing after a failed match and
2107        checking that the new position followed a newline. It was not taking
2108        account of UTF-8 characters correctly.
2109    
2110    23. PCRE was behaving differently from Perl in the way it recognized POSIX
2111        character classes. PCRE was not treating the sequence [:...:] as a
2112        character class unless the ... were all letters. Perl, however, seems to
2113        allow any characters between [: and :], though of course it rejects as
2114        unknown any "names" that contain non-letters, because all the known class
2115        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2116        for example, whereas PCRE did not - it did not recognize a POSIX character
2117        class. This seemed a bit dangerous, so the code has been changed to be
2118        closer to Perl. The behaviour is not identical to Perl, because PCRE will
2119        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2120        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2121        Perl does, and where it didn't before.
2122    
2123    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2124        Windows environments %n is disabled by default.
2125    
2126    
2127  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07
2128  ---------------------  ---------------------

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