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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-09  Version 8.30
5  ----------------------  ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
11        only in quite long subpatterns.
12    
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
15    
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
20    
21    5.  A reference to an unset group with zero minimum repetition was giving
22        totally wrong answers (in non-JavaScript-compatibility mode). For example,
23        /(another)?(\1?)test/ matched against "hello world test". This bug was
24        introduced in release 8.13.
25    
26    6.  Add support for 16-bit character strings (a large amount of work involving
27        many changes and refactorings).
28    
29    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31        from a file.
32    
33    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34        rounding is not applied in this particular case).
35    
36    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
38    
39    10. Get rid of a number of -Wunused-but-set-variable warnings.
40    
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses. It also applied to some
46        assertions.
47    
48    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49        information out of configure.ac instead of relying on pcre.h.generic, which
50        is not stored in the repository.
51    
52    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53        -lreadline.
54    
55    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
56    
57    15. Applied Graycode's patch to put the top-level frame on the stack rather
58        than the heap when not using the stack for recursion. This gives a
59        performance improvement in many cases when recursion is not deep.
60    
61    
62    Version 8.21 12-Dec-2011
63    ------------------------
64    
65    1.  Updating the JIT compiler.
66    
67    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
68        are added as well.
69    
70    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
71        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
72        calling _pcre_jit_exec. Some extra comments are added.
73    
74    4.  (*MARK) settings inside atomic groups that do not contain any capturing
75        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
76        was introduced by change 18 for 8.20.
77    
78    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
79        ECMA-262 standard.
80    
81    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
82        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
83        This bug was probably introduced by change 9 of 8.13.
84    
85    7.  While fixing 6 above, I noticed that a number of other items were being
86        incorrectly rejected as "not fixed length". This arose partly because newer
87        opcodes had not been added to the fixed-length checking code. I have (a)
88        corrected the bug and added tests for these items, and (b) arranged for an
89        error to occur if an unknown opcode is encountered while checking for fixed
90        length instead of just assuming "not fixed length". The items that were
91        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
92        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
93        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
94    
95    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
96        being incorrectly compiled and would have given unpredicatble results.
97    
98    9.  A possessively repeated subpattern with minimum repeat count greater than
99        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
100        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
101        the first (A) could occur when it should not.
102    
103    10. Add a cast and remove a redundant test from the code.
104    
105    11. JIT should use pcre_malloc/pcre_free for allocation.
106    
107    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
108        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
109        is anything other than /usr, -L is still shown).
110    
111    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
112    
113    14. Perl does not support \N without a following name in a [] class; PCRE now
114        also gives an error.
115    
116    15. If a forward reference was repeated with an upper limit of around 2000,
117        it caused the error "internal error: overran compiling workspace". The
118        maximum number of forward references (including repeats) was limited by the
119        internal workspace, and dependent on the LINK_SIZE. The code has been
120        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
121        the default depends on LINK_SIZE. There is a new upper limit (for safety)
122        of around 200,000 forward references. While doing this, I also speeded up
123        the filling in of repeated forward references.
124    
125    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
126        incorrectly expecting the subject to contain another "a" after the start.
127    
128    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
129        in the match, the SKIP should be ignored. This was not happening; instead
130        the SKIP was being treated as NOMATCH. For patterns such as
131        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
132        tested.
133    
134    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
135        now much more compatible with Perl, in particular in cases where the result
136        is a non-match for a non-anchored pattern. For example, if
137        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
138        "m", where previously it did not return a name. A side effect of this
139        change is that for partial matches, the last encountered mark name is
140        returned, as for non matches. A number of tests that were previously not
141        Perl-compatible have been moved into the Perl-compatible test files. The
142        refactoring has had the pleasing side effect of removing one argument from
143        the match() function, thus reducing its stack requirements.
144    
145    19. If the /S+ option was used in pcretest to study a pattern using JIT,
146        subsequent uses of /S (without +) incorrectly behaved like /S+.
147    
148    21. Retrieve executable code size support for the JIT compiler and fixing
149        some warnings.
150    
151    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
152        not work when the shorter character appeared right at the end of the
153        subject string.
154    
155    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
156        systems.
157    
158    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
159        output it when the /M option is used in pcretest.
160    
161    25. The CheckMan script was not being included in the distribution. Also, added
162        an explicit "perl" to run Perl scripts from the PrepareRelease script
163        because this is reportedly needed in Windows.
164    
165    26. If study data was being save in a file and studying had not found a set of
166        "starts with" bytes for the pattern, the data written to the file (though
167        never used) was taken from uninitialized memory and so caused valgrind to
168        complain.
169    
170    27. Updated RunTest.bat as provided by Sheri Pierce.
171    
172    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
173    
174    29. Computation of memory usage for the table of capturing group names was
175        giving an unnecessarily large value.
176    
177    
178    Version 8.20 21-Oct-2011
179    ------------------------
180    
181    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
182        a POSIX class. After further experiments with Perl, which convinced me that
183        Perl has bugs and confusions, a closing square bracket is no longer allowed
184        in a POSIX name. This bug also affected patterns with classes that started
185        with full stops.
186    
187    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
188        captured substring, but while checking the failing first alternative,
189        substring 1 is temporarily captured. If the output vector supplied to
190        pcre_exec() was not big enough for this capture, the yield of the function
191        was still zero ("insufficient space for captured substrings"). This cannot
192        be totally fixed without adding another stack variable, which seems a lot
193        of expense for a edge case. However, I have improved the situation in cases
194        such as /(a)(b)x|abc/ matched against "abc", where the return code
195        indicates that fewer than the maximum number of slots in the ovector have
196        been set.
197    
198    3.  Related to (2) above: when there are more back references in a pattern than
199        slots in the output vector, pcre_exec() uses temporary memory during
200        matching, and copies in the captures as far as possible afterwards. It was
201        using the entire output vector, but this conflicts with the specification
202        that only 2/3 is used for passing back captured substrings. Now it uses
203        only the first 2/3, for compatibility. This is, of course, another edge
204        case.
205    
206    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
207        main code base, and can be used by building with --enable-jit. When this is
208        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
209        runtime --no-jit option is given.
210    
211    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
212        ovector, the return from the function was zero, implying that there were
213        other matches that did not fit. The correct "exactly full" value is now
214        returned.
215    
216    6.  If a subpattern that was called recursively or as a subroutine contained
217        (*PRUNE) or any other control that caused it to give a non-standard return,
218        invalid errors such as "Error -26 (nested recursion at the same subject
219        position)" or even infinite loops could occur.
220    
221    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
222        computing the minimum length on reaching *ACCEPT, and so ended up with the
223        wrong value of 1 rather than 0. Further investigation indicates that
224        computing a minimum subject length in the presence of *ACCEPT is difficult
225        (think back references, subroutine calls), and so I have changed the code
226        so that no minimum is registered for a pattern that contains *ACCEPT.
227    
228    8.  If (*THEN) was present in the first (true) branch of a conditional group,
229        it was not handled as intended. [But see 16 below.]
230    
231    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
232        Sheri Pierce.
233    
234    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
235        the first byte in a match must be "a".
236    
237    11. Change 17 for 8.13 increased the recursion depth for patterns like
238        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
239        pattern contains any instances of (*THEN). If it does not, the old
240        optimizations are restored. It would be nice to do this on a per-group
241        basis, but at the moment that is not feasible.
242    
243    12. In some environments, the output of pcretest -C is CRLF terminated. This
244        broke RunTest's code that checks for the link size. A single white space
245        character after the value is now allowed for.
246    
247    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
248        For "fr", it uses the Windows-specific input and output files.
249    
250    14. If (*THEN) appeared in a group that was called recursively or as a
251        subroutine, it did not work as intended. [But see next item.]
252    
253    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
254        pattern fragments (but not containing any | characters). If A and B are
255        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
256        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
257        D. In other words, Perl considers parentheses that do not contain any |
258        characters to be part of a surrounding alternative, whereas PCRE was
259        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
260        differently. PCRE now behaves in the same way as Perl, except in the case
261        of subroutine/recursion calls such as (?1) which have in any case always
262        been different (but PCRE had them first :-).
263    
264    16. Related to 15 above: Perl does not treat the | in a conditional group as
265        creating alternatives. Such a group is treated in the same way as an
266        ordinary group without any | characters when processing (*THEN). PCRE has
267        been changed to match Perl's behaviour.
268    
269    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
270        RunGrepTest script failed.
271    
272    18. Change 22 for version 13 caused atomic groups to use more stack. This is
273        inevitable for groups that contain captures, but it can lead to a lot of
274        stack use in large patterns. The old behaviour has been restored for atomic
275        groups that do not contain any capturing parentheses.
276    
277    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
278        suppress the check for a minimum subject length at run time. (If it was
279        given to pcre_exec() or pcre_dfa_exec() it did work.)
280    
281    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
282        fail to work when decoding hex characters in data strings in EBCDIC
283        environments.
284    
285    21. It appears that in at least one Mac OS environment, the isxdigit() function
286        is implemented as a macro that evaluates to its argument more than once,
287        contravening the C 90 Standard (I haven't checked a later standard). There
288        was an instance in pcretest which caused it to go wrong when processing
289        \x{...} escapes in subject strings. The has been rewritten to avoid using
290        things like p++ in the argument of isxdigit().
291    
292    
293    Version 8.13 16-Aug-2011
294    ------------------------
295    
296    1.  The Unicode data tables have been updated to Unicode 6.0.0.
297    
298    2.  Two minor typos in pcre_internal.h have been fixed.
299    
300    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
301        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
302        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
303    
304    4.  There were a number of related bugs in the code for matching backrefences
305        caselessly in UTF-8 mode when codes for the characters concerned were
306        different numbers of bytes. For example, U+023A and U+2C65 are an upper
307        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
308        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
309        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
310        2-byte code at the end of the subject (it thought there wasn't enough data
311        left).
312    
313    5.  Comprehensive information about what went wrong is now returned by
314        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
315        as the output vector has at least 2 elements. The offset of the start of
316        the failing character and a reason code are placed in the vector.
317    
318    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
319        now returned is for the first byte of the failing character, instead of the
320        last byte inspected. This is an incompatible change, but I hope it is small
321        enough not to be a problem. It makes the returned offset consistent with
322        pcre_exec() and pcre_dfa_exec().
323    
324    7.  pcretest now gives a text phrase as well as the error number when
325        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
326        failure, the offset and reason code are output.
327    
328    8.  When \R was used with a maximizing quantifier it failed to skip backwards
329        over a \r\n pair if the subsequent match failed. Instead, it just skipped
330        back over a single character (\n). This seems wrong (because it treated the
331        two characters as a single entity when going forwards), conflicts with the
332        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
333        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
334        has been changed.
335    
336    9.  Some internal refactoring has changed the processing so that the handling
337        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
338        time (the PCRE_DOTALL option was changed this way some time ago: version
339        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
340        which was always a bit of a fudge. It also means that there is one less
341        argument for the match() function, which reduces its stack requirements
342        slightly. This change also fixes an incompatibility with Perl: the pattern
343        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
344    
345    10. More internal refactoring has drastically reduced the number of recursive
346        calls to match() for possessively repeated groups such as (abc)++ when
347        using pcre_exec().
348    
349    11. While implementing 10, a number of bugs in the handling of groups were
350        discovered and fixed:
351    
352        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
353        (a|)*(?1) gave a compile-time internal error.
354        ((a|)+)+  did not notice that the outer group could match an empty string.
355        (^a|^)+   was not marked as anchored.
356        (.*a|.*)+ was not marked as matching at start or after a newline.
357    
358    12. Yet more internal refactoring has removed another argument from the match()
359        function. Special calls to this function are now indicated by setting a
360        value in a variable in the "match data" data block.
361    
362    13. Be more explicit in pcre_study() instead of relying on "default" for
363        opcodes that mean there is no starting character; this means that when new
364        ones are added and accidentally left out of pcre_study(), testing should
365        pick them up.
366    
367    14. The -s option of pcretest has been documented for ages as being an old
368        synonym of -m (show memory usage). I have changed it to mean "force study
369        for every regex", that is, assume /S for every regex. This is similar to -i
370        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
371        using it. It makes it easier to run collections of tests with and without
372        study enabled, and thereby test pcre_study() more easily. All the standard
373        tests are now run with and without -s (but some patterns can be marked as
374        "never study" - see 20 below).
375    
376    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
377        restoration of the capturing data to the outer values was not happening
378        correctly.
379    
380    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
381        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
382        pattern had matched an empty string, and so incorrectly returned a no
383        match.
384    
385    17. There was optimizing code for the last branch of non-capturing parentheses,
386        and also for the obeyed branch of a conditional subexpression, which used
387        tail recursion to cut down on stack usage. Unfortunately, now that there is
388        the possibility of (*THEN) occurring in these branches, tail recursion is
389        no longer possible because the return has to be checked for (*THEN). These
390        two optimizations have therefore been removed. [But see 8.20/11 above.]
391    
392    18. If a pattern containing \R was studied, it was assumed that \R always
393        matched two bytes, thus causing the minimum subject length to be
394        incorrectly computed because \R can also match just one byte.
395    
396    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
397        was incorrectly computed.
398    
399    20. If /S is present twice on a test pattern in pcretest input, it now
400        *disables* studying, thereby overriding the use of -s on the command line
401        (see 14 above). This is necessary for one or two tests to keep the output
402        identical in both cases.
403    
404    21. When (*ACCEPT) was used in an assertion that matched an empty string and
405        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
406    
407    22. When an atomic group that contained a capturing parenthesis was
408        successfully matched, but the branch in which it appeared failed, the
409        capturing was not being forgotten if a higher numbered group was later
410        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
411        group 1 to "a", when in fact it should be unset. This applied to multi-
412        branched capturing and non-capturing groups, repeated or not, and also to
413        positive assertions (capturing in negative assertions does not happen
414        in PCRE) and also to nested atomic groups.
415    
416    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
417        subject after a captured substring, to make it easier to tell which of a
418        number of identical substrings has been captured.
419    
420    24. The way atomic groups are processed by pcre_exec() has been changed so that
421        if they are repeated, backtracking one repetition now resets captured
422        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
423        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
424        "aaa". Previously, it would have been "a". As part of this code
425        refactoring, the way recursive calls are handled has also been changed.
426    
427    25. If an assertion condition captured any substrings, they were not passed
428        back unless some other capturing happened later. For example, if
429        (?(?=(a))a) was matched against "a", no capturing was returned.
430    
431    26. When studying a pattern that contained subroutine calls or assertions,
432        the code for finding the minimum length of a possible match was handling
433        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
434        group 1 called group 2 while simultaneously a separate group 2 called group
435        1). A stack overflow occurred in this case. I have fixed this by limiting
436        the recursion depth to 10.
437    
438    27. Updated RunTest.bat in the distribution to the version supplied by Tom
439        Fortmann. This supports explicit test numbers on the command line, and has
440        argument validation and error reporting.
441    
442    28. An instance of \X with an unlimited repeat could fail if at any point the
443        first character it looked at was a mark character.
444    
445    29. Some minor code refactoring concerning Unicode properties and scripts
446        should reduce the stack requirement of match() slightly.
447    
448    30. Added the '=' option to pcretest to check the setting of unused capturing
449        slots at the end of the pattern, which are documented as being -1, but are
450        not included in the return count.
451    
452    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
453        compiled something random. Now it gives a compile-time error (as does
454        Perl).
455    
456    32. A *MARK encountered during the processing of a positive assertion is now
457        recorded and passed back (compatible with Perl).
458    
459    33. If --only-matching or --colour was set on a pcregrep call whose pattern
460        had alternative anchored branches, the search for a second match in a line
461        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
462        matched the line "0102" twice. The same bug affected patterns that started
463        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
464        twice.
465    
466    34. Previously, PCRE did not allow quantification of assertions. However, Perl
467        does, and because of capturing effects, quantifying parenthesized
468        assertions may at times be useful. Quantifiers are now allowed for
469        parenthesized assertions.
470    
471    35. A minor code tidy in pcre_compile() when checking options for \R usage.
472    
473    36. \g was being checked for fancy things in a character class, when it should
474        just be a literal "g".
475    
476    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
477        appearance of a nested POSIX class supersedes an apparent external class.
478        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
479        unescaped square brackets may also appear as part of class names. For
480        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
481        more like Perl. (But see 8.20/1 above.)
482    
483    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
484        was because it thought it was \N{name}, which is not supported).
485    
486    39. Add minix to OS list not supporting the -S option in pcretest.
487    
488    40. PCRE tries to detect cases of infinite recursion at compile time, but it
489        cannot analyze patterns in sufficient detail to catch mutual recursions
490        such as ((?1))((?2)). There is now a runtime test that gives an error if a
491        subgroup is called recursively as a subpattern for a second time at the
492        same position in the subject string. In previous releases this might have
493        been caught by the recursion limit, or it might have run out of stack.
494    
495    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
496        happen only once. PCRE was, however incorrectly giving a compile time error
497        "recursive call could loop indefinitely" because it cannot analyze the
498        pattern in sufficient detail. The compile time test no longer happens when
499        PCRE is compiling a conditional subpattern, but actual runaway loops are
500        now caught at runtime (see 40 above).
501    
502    42. It seems that Perl allows any characters other than a closing parenthesis
503        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
504        has been changed to be the same.
505    
506    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
507        as not to get warnings when autogen.sh is called. Also changed
508        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
509    
510    44. To help people who use pcregrep to scan files containing exceedingly long
511        lines, the following changes have been made:
512    
513        (a) The default value of the buffer size parameter has been increased from
514            8K to 20K. (The actual buffer used is three times this size.)
515    
516        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
517            PCRE is built.
518    
519        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
520            to be set at run time.
521    
522        (d) Numerical values in pcregrep options can be followed by K or M, for
523            example --buffer-size=50K.
524    
525        (e) If a line being scanned overflows pcregrep's buffer, an error is now
526            given and the return code is set to 2.
527    
528    45. Add a pointer to the latest mark to the callout data block.
529    
530    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
531        partial match of an empty string instead of no match. This was specific to
532        the use of ".".
533    
534    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
535        complete match instead of a partial match. This bug was dependent on both
536        the PCRE_UTF8 and PCRE_DOTALL options being set.
537    
538    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
539        starting byte set, because \b was not being ignored.
540    
541    
542    Version 8.12 15-Jan-2011
543    ------------------------
544    
545    1.  Fixed some typos in the markup of the man pages, and wrote a script that
546        checks for such things as part of the documentation building process.
547    
548    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
549        --match-limit and --recursion-limit options (added for 8.11). In
550        particular, this made one of the standard tests fail. (The integer value
551        went into the wrong half of a long int.)
552    
553    3.  If the --colour option was given to pcregrep with -v (invert match), it
554        did strange things, either producing crazy output, or crashing. It should,
555        of course, ignore a request for colour when reporting lines that do not
556        match.
557    
558    4.  Another pcregrep bug caused similar problems if --colour was specified with
559        -M (multiline) and the pattern match finished with a line ending.
560    
561    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
562        matched in multiline mode, the following line was shown as part of the
563        match. This seems wrong, so I have changed it.
564    
565    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
566        the check for further matches in the same line (so they could be coloured)
567        to overrun the end of the current line. If another match was found, it was
568        incorrectly shown (and then shown again when found in the next line).
569    
570    7.  If pcregrep was compiled under Windows, there was a reference to the
571        function pcregrep_exit() before it was defined. I am assuming this was
572        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
573        reported by a user. I've moved the definition above the reference.
574    
575    
576    Version 8.11 10-Dec-2010
577    ------------------------
578    
579    1.  (*THEN) was not working properly if there were untried alternatives prior
580        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
581        backtracked to try for "b" instead of moving to the next alternative branch
582        at the same level (in this case, to look for "c"). The Perl documentation
583        is clear that when (*THEN) is backtracked onto, it goes to the "next
584        alternative in the innermost enclosing group".
585    
586    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
587        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
588        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
589        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
590        (*THEN).
591    
592    3.  If \s appeared in a character class, it removed the VT character from
593        the class, even if it had been included by some previous item, for example
594        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
595        of \s, but is part of the POSIX "space" class.)
596    
597    4.  A partial match never returns an empty string (because you can always
598        match an empty string at the end of the subject); however the checking for
599        an empty string was starting at the "start of match" point. This has been
600        changed to the "earliest inspected character" point, because the returned
601        data for a partial match starts at this character. This means that, for
602        example, /(?<=abc)def/ gives a partial match for the subject "abc"
603        (previously it gave "no match").
604    
605    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
606        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
607        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
608        has an implication that the given string is incomplete (because a partial
609        match is preferred over a full match). For this reason, these items now
610        give a partial match in this situation. [Aside: previously, the one case
611        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
612        match rather than a full match, which was wrong by the old rules, but is
613        now correct.]
614    
615    6.  There was a bug in the handling of #-introduced comments, recognized when
616        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
617        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
618        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
619        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
620        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
621        places in pcre_compile().
622    
623    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
624        comments when looking ahead for named forward references to subpatterns,
625        the only newline sequence it recognized was NL. It now handles newlines
626        according to the set newline convention.
627    
628    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
629        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
630        cater for a lack of strerror(). These oversights have been fixed.
631    
632    9.  Added --match-limit and --recursion-limit to pcregrep.
633    
634    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
635    
636    11. When the -o option was used, pcregrep was setting a return code of 1, even
637        when matches were found, and --line-buffered was not being honoured.
638    
639    12. Added an optional parentheses number to the -o and --only-matching options
640        of pcregrep.
641    
642    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
643        can match an empty string. The code to do it in pcretest and pcredemo
644        needed fixing:
645    
646        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
647            only one byte after an empty string match just before CRLF (this case
648            just got forgotten; "any" and "anycrlf" were OK).
649    
650        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
651            mode when an empty string match preceded an ASCII character followed by
652            a non-ASCII character. (The code for advancing by one character rather
653            than one byte was nonsense.)
654    
655        (c) The pcredemo.c sample program did not have any code at all to handle
656            the cases when CRLF is a valid newline sequence.
657    
658    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
659        as a starting offset was within the subject string. There is now a new
660        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
661        negative or greater than the length of the string. In order to test this,
662        pcretest is extended to allow the setting of negative starting offsets.
663    
664    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
665        starting offset points to the beginning of a UTF-8 character was
666        unnecessarily clumsy. I tidied it up.
667    
668    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
669        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
670    
671    17. Nobody had reported that the --include_dir option, which was added in
672        release 7.7 should have been called --include-dir (hyphen, not underscore)
673        for compatibility with GNU grep. I have changed it to --include-dir, but
674        left --include_dir as an undocumented synonym, and the same for
675        --exclude-dir, though that is not available in GNU grep, at least as of
676        release 2.5.4.
677    
678    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
679        characters from a string of bytes) have been redefined so as not to use
680        loops, in order to improve performance in some environments. At the same
681        time, I abstracted some of the common code into auxiliary macros to save
682        repetition (this should not affect the compiled code).
683    
684    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
685        compile-time error is now given if \c is not followed by an ASCII
686        character, that is, a byte less than 128. (In EBCDIC mode, the code is
687        different, and any byte value is allowed.)
688    
689    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
690        START_OPTIMIZE option, which is now allowed at compile time - but just
691        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
692        to pcregrep and other applications that have no direct access to PCRE
693        options. The new /Y option in pcretest sets this option when calling
694        pcre_compile().
695    
696    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
697        back references. Groups containing recursive back references were forced to
698        be atomic by that change, but in the case of named groups, the amount of
699        memory required was incorrectly computed, leading to "Failed: internal
700        error: code overflow". This has been fixed.
701    
702    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
703        pcretest.c, to avoid build problems in some Borland environments.
704    
705    
706    Version 8.10 25-Jun-2010
707    ------------------------
708    
709    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
710        THEN.
711    
712    2.  (*ACCEPT) was not working when inside an atomic group.
713    
714    3.  Inside a character class, \B is treated as a literal by default, but
715        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
716        causes the error). The code is unchanged, but I tidied the documentation.
717    
718    4.  Inside a character class, PCRE always treated \R and \X as literals,
719        whereas Perl faults them if its -w option is set. I have changed PCRE so
720        that it faults them when PCRE_EXTRA is set.
721    
722    5.  Added support for \N, which always matches any character other than
723        newline. (It is the same as "." when PCRE_DOTALL is not set.)
724    
725    6.  When compiling pcregrep with newer versions of gcc which may have
726        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
727        declared with attribute warn_unused_result" were given. Just casting the
728        result to (void) does not stop the warnings; a more elaborate fudge is
729        needed. I've used a macro to implement this.
730    
731    7.  Minor change to pcretest.c to avoid a compiler warning.
732    
733    8.  Added four artifical Unicode properties to help with an option to make
734        \s etc use properties (see next item). The new properties are: Xan
735        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
736    
737    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
738        use Unicode properties. (*UCP) at the start of a pattern can be used to set
739        this option. Modified pcretest to add /W to test this facility. Added
740        REG_UCP to make it available via the POSIX interface.
741    
742    10. Added --line-buffered to pcregrep.
743    
744    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
745        studied, and the match started with a letter with a code point greater than
746        127 whose first byte was different to the first byte of the other case of
747        the letter, the other case of this starting letter was not recognized
748        (#976).
749    
750    12. If a pattern that was studied started with a repeated Unicode property
751        test, for example, \p{Nd}+, there was the theoretical possibility of
752        setting up an incorrect bitmap of starting bytes, but fortunately it could
753        not have actually happened in practice until change 8 above was made (it
754        added property types that matched character-matching opcodes).
755    
756    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
757        possible starting bytes for non-anchored patterns.
758    
759    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
760        \R, and also a number of cases that involve Unicode properties, both
761        explicit and implicit when PCRE_UCP is set.
762    
763    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
764        input, it could crash or give wrong results if characters with values
765        greater than 0xc0 were present in the subject string. (Detail: it assumed
766        UTF-8 input when processing these items.)
767    
768    16. Added a lot of (int) casts to avoid compiler warnings in systems where
769        size_t is 64-bit (#991).
770    
771    17. Added a check for running out of memory when PCRE is compiled with
772        --disable-stack-for-recursion (#990).
773    
774    18. If the last data line in a file for pcretest does not have a newline on
775        the end, a newline was missing in the output.
776    
777    19. The default pcre_chartables.c file recognizes only ASCII characters (values
778        less than 128) in its various bitmaps. However, there is a facility for
779        generating tables according to the current locale when PCRE is compiled. It
780        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
781        characters, are recognized by isspace() and therefore were getting set in
782        these tables, and indeed these tables seem to approximate to ISO 8859. This
783        caused a problem in UTF-8 mode when pcre_study() was used to create a list
784        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
785        which of course cannot start UTF-8 characters. I have changed the code so
786        that only real ASCII characters (less than 128) and the correct starting
787        bytes for UTF-8 encodings are set for characters greater than 127 when in
788        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
789        altogether.)
790    
791    20. Added the /T option to pcretest so as to be able to run tests with non-
792        standard character tables, thus making it possible to include the tests
793        used for 19 above in the standard set of tests.
794    
795    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
796        reference to a subpattern the other side of a comment that contains an
797        opening parenthesis caused either an internal compiling error, or a
798        reference to the wrong subpattern.
799    
800    
801    Version 8.02 19-Mar-2010
802    ------------------------
803    
804    1.  The Unicode data tables have been updated to Unicode 5.2.0.
805    
806    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
807        configured.
808    
809    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
810        original author of that file, following a query about its status.
811    
812    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
813        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
814    
815    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
816        quantifier applied to a forward-referencing subroutine call, could compile
817        incorrect code or give the error "internal error: previously-checked
818        referenced subpattern not found".
819    
820    6.  Both MS Visual Studio and Symbian OS have problems with initializing
821        variables to point to external functions. For these systems, therefore,
822        pcre_malloc etc. are now initialized to local functions that call the
823        relevant global functions.
824    
825    7.  There were two entries missing in the vectors called coptable and poptable
826        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
827        I've fixed the data, and added a kludgy way of testing at compile time that
828        the lengths are correct (equal to the number of opcodes).
829    
830    8.  Following on from 7, I added a similar kludge to check the length of the
831        eint vector in pcreposix.c.
832    
833    9.  Error texts for pcre_compile() are held as one long string to avoid too
834        much relocation at load time. To find a text, the string is searched,
835        counting zeros. There was no check for running off the end of the string,
836        which could happen if a new error number was added without updating the
837        string.
838    
839    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
840    
841    11. \K was not working if it appeared in an atomic group or in a group that
842        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
843        \K is "not well defined" if used in an assertion. PCRE now accepts it if
844        the assertion is positive, but not if it is negative.
845    
846    12. Change 11 fortuitously reduced the size of the stack frame used in the
847        "match()" function of pcre_exec.c by one pointer. Forthcoming
848        implementation of support for (*MARK) will need an extra pointer on the
849        stack; I have reserved it now, so that the stack frame size does not
850        decrease.
851    
852    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
853        item in branch that calls a recursion is a subroutine call - as in the
854        second branch in the above example - was incorrectly given the compile-
855        time error "recursive call could loop indefinitely" because pcre_compile()
856        was not correctly checking the subroutine for matching a non-empty string.
857    
858    14. The checks for overrunning compiling workspace could trigger after an
859        overrun had occurred. This is a "should never occur" error, but it can be
860        triggered by pathological patterns such as hundreds of nested parentheses.
861        The checks now trigger 100 bytes before the end of the workspace.
862    
863    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
864    
865    
866    Version 8.01 19-Jan-2010
867    ------------------------
868    
869  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  If a pattern contained a conditional subpattern with only one branch (in
870      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
871      computed the wrong minimum data length (which is of course zero for such      computed the wrong minimum data length (which is of course zero for such
872      subpatterns).      subpatterns). This could cause incorrect "no match" results.
873    
874  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
875      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
# Line 61  Version 8.01 11-Dec-09 Line 923  Version 8.01 11-Dec-09
923      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
924    
925        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
926          under Win32.            under Win32.
927        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
928          therefore missing the function definition.            therefore missing the function definition.
929        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
930        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
931        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
932    
933  11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these  11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
934      messages were output:      messages were output:
935    
936        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
937        rerunning libtoolize, to keep the correct libtool macros in-tree.        rerunning libtoolize, to keep the correct libtool macros in-tree.
938        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
939    
940      I have done both of these things.      I have done both of these things.
941    
942    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
943        most of the time, it *can* run out if it is given a pattern that contains a
944        runaway infinite recursion. I updated the discussion in the pcrestack man
945        page.
946    
947    13. Now that we have gone to the x.xx style of version numbers, the minor
948        version may start with zero. Using 08 or 09 is a bad idea because users
949        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
950        interpreted as invalid octal numbers. I've updated the previous comment in
951        configure.ac, and also added a check that gives an error if 08 or 09 are
952        used.
953    
954    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
955        causing partial matching to fail when the end of the subject matched \W
956        in a UTF-8 pattern where \W was quantified with a minimum of 3.
957    
958    15. There were some discrepancies between the declarations in pcre_internal.h
959        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
960        their definitions. The declarations used "const uschar *" and the
961        definitions used USPTR. Even though USPTR is normally defined as "const
962        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
963        reported that: "This difference in casting confuses some C++ compilers, for
964        example, SunCC recognizes above declarations as different functions and
965        generates broken code for hbpcre." I have changed the declarations to use
966        USPTR.
967    
968    16. GNU libtool is named differently on some systems. The autogen.sh script now
969        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
970        (FreeBSD).
971    
972    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
973        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
974        comment: "Figure out how to create a longlong from a string: strtoll and
975        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
976        instance, but it only takes 2 args instead of 3!"
977    
978    18. A subtle bug concerned with back references has been fixed by a change of
979        specification, with a corresponding code fix. A pattern such as
980        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
981        refers, was giving matches when it shouldn't. For example, xa=xaaa would
982        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
983        same bug. Such groups have to be quantified to be useful, or contained
984        inside another quantified group. (If there's no repetition, the reference
985        can never match.) The problem arises because, having left the group and
986        moved on to the rest of the pattern, a later failure that backtracks into
987        the group uses the captured value from the final iteration of the group
988        rather than the correct earlier one. I have fixed this in PCRE by forcing
989        any group that contains a reference to itself to be an atomic group; that
990        is, there cannot be any backtracking into it once it has completed. This is
991        similar to recursive and subroutine calls.
992    
993    
994  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09

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