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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 12-Mar-07  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    
37    Version 8.21 12-Dec-2011
38    ------------------------
39    
40    1.  Updating the JIT compiler.
41    
42    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
43        are added as well.
44    
45    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
46        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
47        calling _pcre_jit_exec. Some extra comments are added.
48    
49    4.  (*MARK) settings inside atomic groups that do not contain any capturing
50        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
51        was introduced by change 18 for 8.20.
52    
53    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
54        ECMA-262 standard.
55    
56    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
57        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
58        This bug was probably introduced by change 9 of 8.13.
59    
60    7.  While fixing 6 above, I noticed that a number of other items were being
61        incorrectly rejected as "not fixed length". This arose partly because newer
62        opcodes had not been added to the fixed-length checking code. I have (a)
63        corrected the bug and added tests for these items, and (b) arranged for an
64        error to occur if an unknown opcode is encountered while checking for fixed
65        length instead of just assuming "not fixed length". The items that were
66        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
67        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
68        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
69    
70    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
71        being incorrectly compiled and would have given unpredicatble results.
72    
73    9.  A possessively repeated subpattern with minimum repeat count greater than
74        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
75        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
76        the first (A) could occur when it should not.
77    
78    10. Add a cast and remove a redundant test from the code.
79    
80    11. JIT should use pcre_malloc/pcre_free for allocation.
81    
82    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
83        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
84        is anything other than /usr, -L is still shown).
85    
86    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
87    
88    14. Perl does not support \N without a following name in a [] class; PCRE now
89        also gives an error.
90    
91    15. If a forward reference was repeated with an upper limit of around 2000,
92        it caused the error "internal error: overran compiling workspace". The
93        maximum number of forward references (including repeats) was limited by the
94        internal workspace, and dependent on the LINK_SIZE. The code has been
95        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
96        the default depends on LINK_SIZE. There is a new upper limit (for safety)
97        of around 200,000 forward references. While doing this, I also speeded up
98        the filling in of repeated forward references.
99    
100    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
101        incorrectly expecting the subject to contain another "a" after the start.
102    
103    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
104        in the match, the SKIP should be ignored. This was not happening; instead
105        the SKIP was being treated as NOMATCH. For patterns such as
106        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
107        tested.
108    
109    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
110        now much more compatible with Perl, in particular in cases where the result
111        is a non-match for a non-anchored pattern. For example, if
112        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
113        "m", where previously it did not return a name. A side effect of this
114        change is that for partial matches, the last encountered mark name is
115        returned, as for non matches. A number of tests that were previously not
116        Perl-compatible have been moved into the Perl-compatible test files. The
117        refactoring has had the pleasing side effect of removing one argument from
118        the match() function, thus reducing its stack requirements.
119    
120    19. If the /S+ option was used in pcretest to study a pattern using JIT,
121        subsequent uses of /S (without +) incorrectly behaved like /S+.
122    
123    21. Retrieve executable code size support for the JIT compiler and fixing
124        some warnings.
125    
126    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
127        not work when the shorter character appeared right at the end of the
128        subject string.
129    
130    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
131        systems.
132    
133    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
134        output it when the /M option is used in pcretest.
135    
136    25. The CheckMan script was not being included in the distribution. Also, added
137        an explicit "perl" to run Perl scripts from the PrepareRelease script
138        because this is reportedly needed in Windows.
139    
140    26. If study data was being save in a file and studying had not found a set of
141        "starts with" bytes for the pattern, the data written to the file (though
142        never used) was taken from uninitialized memory and so caused valgrind to
143        complain.
144    
145    27. Updated RunTest.bat as provided by Sheri Pierce.
146    
147    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
148    
149    29. Computation of memory usage for the table of capturing group names was
150        giving an unnecessarily large value.
151    
152    
153    Version 8.20 21-Oct-2011
154    ------------------------
155    
156    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
157        a POSIX class. After further experiments with Perl, which convinced me that
158        Perl has bugs and confusions, a closing square bracket is no longer allowed
159        in a POSIX name. This bug also affected patterns with classes that started
160        with full stops.
161    
162    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
163        captured substring, but while checking the failing first alternative,
164        substring 1 is temporarily captured. If the output vector supplied to
165        pcre_exec() was not big enough for this capture, the yield of the function
166        was still zero ("insufficient space for captured substrings"). This cannot
167        be totally fixed without adding another stack variable, which seems a lot
168        of expense for a edge case. However, I have improved the situation in cases
169        such as /(a)(b)x|abc/ matched against "abc", where the return code
170        indicates that fewer than the maximum number of slots in the ovector have
171        been set.
172    
173    3.  Related to (2) above: when there are more back references in a pattern than
174        slots in the output vector, pcre_exec() uses temporary memory during
175        matching, and copies in the captures as far as possible afterwards. It was
176        using the entire output vector, but this conflicts with the specification
177        that only 2/3 is used for passing back captured substrings. Now it uses
178        only the first 2/3, for compatibility. This is, of course, another edge
179        case.
180    
181    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
182        main code base, and can be used by building with --enable-jit. When this is
183        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
184        runtime --no-jit option is given.
185    
186    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
187        ovector, the return from the function was zero, implying that there were
188        other matches that did not fit. The correct "exactly full" value is now
189        returned.
190    
191    6.  If a subpattern that was called recursively or as a subroutine contained
192        (*PRUNE) or any other control that caused it to give a non-standard return,
193        invalid errors such as "Error -26 (nested recursion at the same subject
194        position)" or even infinite loops could occur.
195    
196    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
197        computing the minimum length on reaching *ACCEPT, and so ended up with the
198        wrong value of 1 rather than 0. Further investigation indicates that
199        computing a minimum subject length in the presence of *ACCEPT is difficult
200        (think back references, subroutine calls), and so I have changed the code
201        so that no minimum is registered for a pattern that contains *ACCEPT.
202    
203    8.  If (*THEN) was present in the first (true) branch of a conditional group,
204        it was not handled as intended. [But see 16 below.]
205    
206    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
207        Sheri Pierce.
208    
209    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
210        the first byte in a match must be "a".
211    
212    11. Change 17 for 8.13 increased the recursion depth for patterns like
213        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
214        pattern contains any instances of (*THEN). If it does not, the old
215        optimizations are restored. It would be nice to do this on a per-group
216        basis, but at the moment that is not feasible.
217    
218    12. In some environments, the output of pcretest -C is CRLF terminated. This
219        broke RunTest's code that checks for the link size. A single white space
220        character after the value is now allowed for.
221    
222    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
223        For "fr", it uses the Windows-specific input and output files.
224    
225    14. If (*THEN) appeared in a group that was called recursively or as a
226        subroutine, it did not work as intended. [But see next item.]
227    
228    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
229        pattern fragments (but not containing any | characters). If A and B are
230        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
231        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
232        D. In other words, Perl considers parentheses that do not contain any |
233        characters to be part of a surrounding alternative, whereas PCRE was
234        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
235        differently. PCRE now behaves in the same way as Perl, except in the case
236        of subroutine/recursion calls such as (?1) which have in any case always
237        been different (but PCRE had them first :-).
238    
239    16. Related to 15 above: Perl does not treat the | in a conditional group as
240        creating alternatives. Such a group is treated in the same way as an
241        ordinary group without any | characters when processing (*THEN). PCRE has
242        been changed to match Perl's behaviour.
243    
244    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
245        RunGrepTest script failed.
246    
247    18. Change 22 for version 13 caused atomic groups to use more stack. This is
248        inevitable for groups that contain captures, but it can lead to a lot of
249        stack use in large patterns. The old behaviour has been restored for atomic
250        groups that do not contain any capturing parentheses.
251    
252    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
253        suppress the check for a minimum subject length at run time. (If it was
254        given to pcre_exec() or pcre_dfa_exec() it did work.)
255    
256    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
257        fail to work when decoding hex characters in data strings in EBCDIC
258        environments.
259    
260    21. It appears that in at least one Mac OS environment, the isxdigit() function
261        is implemented as a macro that evaluates to its argument more than once,
262        contravening the C 90 Standard (I haven't checked a later standard). There
263        was an instance in pcretest which caused it to go wrong when processing
264        \x{...} escapes in subject strings. The has been rewritten to avoid using
265        things like p++ in the argument of isxdigit().
266    
267    
268    Version 8.13 16-Aug-2011
269    ------------------------
270    
271    1.  The Unicode data tables have been updated to Unicode 6.0.0.
272    
273    2.  Two minor typos in pcre_internal.h have been fixed.
274    
275    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
276        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
277        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
278    
279    4.  There were a number of related bugs in the code for matching backrefences
280        caselessly in UTF-8 mode when codes for the characters concerned were
281        different numbers of bytes. For example, U+023A and U+2C65 are an upper
282        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
283        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
284        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
285        2-byte code at the end of the subject (it thought there wasn't enough data
286        left).
287    
288    5.  Comprehensive information about what went wrong is now returned by
289        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
290        as the output vector has at least 2 elements. The offset of the start of
291        the failing character and a reason code are placed in the vector.
292    
293    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
294        now returned is for the first byte of the failing character, instead of the
295        last byte inspected. This is an incompatible change, but I hope it is small
296        enough not to be a problem. It makes the returned offset consistent with
297        pcre_exec() and pcre_dfa_exec().
298    
299    7.  pcretest now gives a text phrase as well as the error number when
300        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
301        failure, the offset and reason code are output.
302    
303    8.  When \R was used with a maximizing quantifier it failed to skip backwards
304        over a \r\n pair if the subsequent match failed. Instead, it just skipped
305        back over a single character (\n). This seems wrong (because it treated the
306        two characters as a single entity when going forwards), conflicts with the
307        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
308        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
309        has been changed.
310    
311    9.  Some internal refactoring has changed the processing so that the handling
312        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
313        time (the PCRE_DOTALL option was changed this way some time ago: version
314        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
315        which was always a bit of a fudge. It also means that there is one less
316        argument for the match() function, which reduces its stack requirements
317        slightly. This change also fixes an incompatibility with Perl: the pattern
318        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
319    
320    10. More internal refactoring has drastically reduced the number of recursive
321        calls to match() for possessively repeated groups such as (abc)++ when
322        using pcre_exec().
323    
324    11. While implementing 10, a number of bugs in the handling of groups were
325        discovered and fixed:
326    
327        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
328        (a|)*(?1) gave a compile-time internal error.
329        ((a|)+)+  did not notice that the outer group could match an empty string.
330        (^a|^)+   was not marked as anchored.
331        (.*a|.*)+ was not marked as matching at start or after a newline.
332    
333    12. Yet more internal refactoring has removed another argument from the match()
334        function. Special calls to this function are now indicated by setting a
335        value in a variable in the "match data" data block.
336    
337    13. Be more explicit in pcre_study() instead of relying on "default" for
338        opcodes that mean there is no starting character; this means that when new
339        ones are added and accidentally left out of pcre_study(), testing should
340        pick them up.
341    
342    14. The -s option of pcretest has been documented for ages as being an old
343        synonym of -m (show memory usage). I have changed it to mean "force study
344        for every regex", that is, assume /S for every regex. This is similar to -i
345        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
346        using it. It makes it easier to run collections of tests with and without
347        study enabled, and thereby test pcre_study() more easily. All the standard
348        tests are now run with and without -s (but some patterns can be marked as
349        "never study" - see 20 below).
350    
351    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
352        restoration of the capturing data to the outer values was not happening
353        correctly.
354    
355    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
356        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
357        pattern had matched an empty string, and so incorrectly returned a no
358        match.
359    
360    17. There was optimizing code for the last branch of non-capturing parentheses,
361        and also for the obeyed branch of a conditional subexpression, which used
362        tail recursion to cut down on stack usage. Unfortunately, now that there is
363        the possibility of (*THEN) occurring in these branches, tail recursion is
364        no longer possible because the return has to be checked for (*THEN). These
365        two optimizations have therefore been removed. [But see 8.20/11 above.]
366    
367    18. If a pattern containing \R was studied, it was assumed that \R always
368        matched two bytes, thus causing the minimum subject length to be
369        incorrectly computed because \R can also match just one byte.
370    
371    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
372        was incorrectly computed.
373    
374    20. If /S is present twice on a test pattern in pcretest input, it now
375        *disables* studying, thereby overriding the use of -s on the command line
376        (see 14 above). This is necessary for one or two tests to keep the output
377        identical in both cases.
378    
379    21. When (*ACCEPT) was used in an assertion that matched an empty string and
380        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
381    
382    22. When an atomic group that contained a capturing parenthesis was
383        successfully matched, but the branch in which it appeared failed, the
384        capturing was not being forgotten if a higher numbered group was later
385        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
386        group 1 to "a", when in fact it should be unset. This applied to multi-
387        branched capturing and non-capturing groups, repeated or not, and also to
388        positive assertions (capturing in negative assertions does not happen
389        in PCRE) and also to nested atomic groups.
390    
391    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
392        subject after a captured substring, to make it easier to tell which of a
393        number of identical substrings has been captured.
394    
395    24. The way atomic groups are processed by pcre_exec() has been changed so that
396        if they are repeated, backtracking one repetition now resets captured
397        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
398        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
399        "aaa". Previously, it would have been "a". As part of this code
400        refactoring, the way recursive calls are handled has also been changed.
401    
402    25. If an assertion condition captured any substrings, they were not passed
403        back unless some other capturing happened later. For example, if
404        (?(?=(a))a) was matched against "a", no capturing was returned.
405    
406    26. When studying a pattern that contained subroutine calls or assertions,
407        the code for finding the minimum length of a possible match was handling
408        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
409        group 1 called group 2 while simultaneously a separate group 2 called group
410        1). A stack overflow occurred in this case. I have fixed this by limiting
411        the recursion depth to 10.
412    
413    27. Updated RunTest.bat in the distribution to the version supplied by Tom
414        Fortmann. This supports explicit test numbers on the command line, and has
415        argument validation and error reporting.
416    
417    28. An instance of \X with an unlimited repeat could fail if at any point the
418        first character it looked at was a mark character.
419    
420    29. Some minor code refactoring concerning Unicode properties and scripts
421        should reduce the stack requirement of match() slightly.
422    
423    30. Added the '=' option to pcretest to check the setting of unused capturing
424        slots at the end of the pattern, which are documented as being -1, but are
425        not included in the return count.
426    
427    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
428        compiled something random. Now it gives a compile-time error (as does
429        Perl).
430    
431    32. A *MARK encountered during the processing of a positive assertion is now
432        recorded and passed back (compatible with Perl).
433    
434    33. If --only-matching or --colour was set on a pcregrep call whose pattern
435        had alternative anchored branches, the search for a second match in a line
436        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
437        matched the line "0102" twice. The same bug affected patterns that started
438        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
439        twice.
440    
441    34. Previously, PCRE did not allow quantification of assertions. However, Perl
442        does, and because of capturing effects, quantifying parenthesized
443        assertions may at times be useful. Quantifiers are now allowed for
444        parenthesized assertions.
445    
446    35. A minor code tidy in pcre_compile() when checking options for \R usage.
447    
448    36. \g was being checked for fancy things in a character class, when it should
449        just be a literal "g".
450    
451    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
452        appearance of a nested POSIX class supersedes an apparent external class.
453        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
454        unescaped square brackets may also appear as part of class names. For
455        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
456        more like Perl. (But see 8.20/1 above.)
457    
458    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
459        was because it thought it was \N{name}, which is not supported).
460    
461    39. Add minix to OS list not supporting the -S option in pcretest.
462    
463    40. PCRE tries to detect cases of infinite recursion at compile time, but it
464        cannot analyze patterns in sufficient detail to catch mutual recursions
465        such as ((?1))((?2)). There is now a runtime test that gives an error if a
466        subgroup is called recursively as a subpattern for a second time at the
467        same position in the subject string. In previous releases this might have
468        been caught by the recursion limit, or it might have run out of stack.
469    
470    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
471        happen only once. PCRE was, however incorrectly giving a compile time error
472        "recursive call could loop indefinitely" because it cannot analyze the
473        pattern in sufficient detail. The compile time test no longer happens when
474        PCRE is compiling a conditional subpattern, but actual runaway loops are
475        now caught at runtime (see 40 above).
476    
477    42. It seems that Perl allows any characters other than a closing parenthesis
478        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
479        has been changed to be the same.
480    
481    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
482        as not to get warnings when autogen.sh is called. Also changed
483        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
484    
485    44. To help people who use pcregrep to scan files containing exceedingly long
486        lines, the following changes have been made:
487    
488        (a) The default value of the buffer size parameter has been increased from
489            8K to 20K. (The actual buffer used is three times this size.)
490    
491        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
492            PCRE is built.
493    
494        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
495            to be set at run time.
496    
497        (d) Numerical values in pcregrep options can be followed by K or M, for
498            example --buffer-size=50K.
499    
500        (e) If a line being scanned overflows pcregrep's buffer, an error is now
501            given and the return code is set to 2.
502    
503    45. Add a pointer to the latest mark to the callout data block.
504    
505    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
506        partial match of an empty string instead of no match. This was specific to
507        the use of ".".
508    
509    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
510        complete match instead of a partial match. This bug was dependent on both
511        the PCRE_UTF8 and PCRE_DOTALL options being set.
512    
513    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
514        starting byte set, because \b was not being ignored.
515    
516    
517    Version 8.12 15-Jan-2011
518    ------------------------
519    
520    1.  Fixed some typos in the markup of the man pages, and wrote a script that
521        checks for such things as part of the documentation building process.
522    
523    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
524        --match-limit and --recursion-limit options (added for 8.11). In
525        particular, this made one of the standard tests fail. (The integer value
526        went into the wrong half of a long int.)
527    
528    3.  If the --colour option was given to pcregrep with -v (invert match), it
529        did strange things, either producing crazy output, or crashing. It should,
530        of course, ignore a request for colour when reporting lines that do not
531        match.
532    
533    4.  Another pcregrep bug caused similar problems if --colour was specified with
534        -M (multiline) and the pattern match finished with a line ending.
535    
536    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
537        matched in multiline mode, the following line was shown as part of the
538        match. This seems wrong, so I have changed it.
539    
540    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
541        the check for further matches in the same line (so they could be coloured)
542        to overrun the end of the current line. If another match was found, it was
543        incorrectly shown (and then shown again when found in the next line).
544    
545    7.  If pcregrep was compiled under Windows, there was a reference to the
546        function pcregrep_exit() before it was defined. I am assuming this was
547        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
548        reported by a user. I've moved the definition above the reference.
549    
550    
551    Version 8.11 10-Dec-2010
552    ------------------------
553    
554    1.  (*THEN) was not working properly if there were untried alternatives prior
555        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
556        backtracked to try for "b" instead of moving to the next alternative branch
557        at the same level (in this case, to look for "c"). The Perl documentation
558        is clear that when (*THEN) is backtracked onto, it goes to the "next
559        alternative in the innermost enclosing group".
560    
561    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
562        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
563        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
564        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
565        (*THEN).
566    
567    3.  If \s appeared in a character class, it removed the VT character from
568        the class, even if it had been included by some previous item, for example
569        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
570        of \s, but is part of the POSIX "space" class.)
571    
572    4.  A partial match never returns an empty string (because you can always
573        match an empty string at the end of the subject); however the checking for
574        an empty string was starting at the "start of match" point. This has been
575        changed to the "earliest inspected character" point, because the returned
576        data for a partial match starts at this character. This means that, for
577        example, /(?<=abc)def/ gives a partial match for the subject "abc"
578        (previously it gave "no match").
579    
580    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
581        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
582        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
583        has an implication that the given string is incomplete (because a partial
584        match is preferred over a full match). For this reason, these items now
585        give a partial match in this situation. [Aside: previously, the one case
586        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
587        match rather than a full match, which was wrong by the old rules, but is
588        now correct.]
589    
590    6.  There was a bug in the handling of #-introduced comments, recognized when
591        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
592        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
593        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
594        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
595        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
596        places in pcre_compile().
597    
598    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
599        comments when looking ahead for named forward references to subpatterns,
600        the only newline sequence it recognized was NL. It now handles newlines
601        according to the set newline convention.
602    
603    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
604        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
605        cater for a lack of strerror(). These oversights have been fixed.
606    
607    9.  Added --match-limit and --recursion-limit to pcregrep.
608    
609    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
610    
611    11. When the -o option was used, pcregrep was setting a return code of 1, even
612        when matches were found, and --line-buffered was not being honoured.
613    
614    12. Added an optional parentheses number to the -o and --only-matching options
615        of pcregrep.
616    
617    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
618        can match an empty string. The code to do it in pcretest and pcredemo
619        needed fixing:
620    
621        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
622            only one byte after an empty string match just before CRLF (this case
623            just got forgotten; "any" and "anycrlf" were OK).
624    
625        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
626            mode when an empty string match preceded an ASCII character followed by
627            a non-ASCII character. (The code for advancing by one character rather
628            than one byte was nonsense.)
629    
630        (c) The pcredemo.c sample program did not have any code at all to handle
631            the cases when CRLF is a valid newline sequence.
632    
633    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
634        as a starting offset was within the subject string. There is now a new
635        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
636        negative or greater than the length of the string. In order to test this,
637        pcretest is extended to allow the setting of negative starting offsets.
638    
639    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
640        starting offset points to the beginning of a UTF-8 character was
641        unnecessarily clumsy. I tidied it up.
642    
643    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
644        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
645    
646    17. Nobody had reported that the --include_dir option, which was added in
647        release 7.7 should have been called --include-dir (hyphen, not underscore)
648        for compatibility with GNU grep. I have changed it to --include-dir, but
649        left --include_dir as an undocumented synonym, and the same for
650        --exclude-dir, though that is not available in GNU grep, at least as of
651        release 2.5.4.
652    
653    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
654        characters from a string of bytes) have been redefined so as not to use
655        loops, in order to improve performance in some environments. At the same
656        time, I abstracted some of the common code into auxiliary macros to save
657        repetition (this should not affect the compiled code).
658    
659    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
660        compile-time error is now given if \c is not followed by an ASCII
661        character, that is, a byte less than 128. (In EBCDIC mode, the code is
662        different, and any byte value is allowed.)
663    
664    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
665        START_OPTIMIZE option, which is now allowed at compile time - but just
666        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
667        to pcregrep and other applications that have no direct access to PCRE
668        options. The new /Y option in pcretest sets this option when calling
669        pcre_compile().
670    
671    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
672        back references. Groups containing recursive back references were forced to
673        be atomic by that change, but in the case of named groups, the amount of
674        memory required was incorrectly computed, leading to "Failed: internal
675        error: code overflow". This has been fixed.
676    
677    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
678        pcretest.c, to avoid build problems in some Borland environments.
679    
680    
681    Version 8.10 25-Jun-2010
682    ------------------------
683    
684    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
685        THEN.
686    
687    2.  (*ACCEPT) was not working when inside an atomic group.
688    
689    3.  Inside a character class, \B is treated as a literal by default, but
690        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
691        causes the error). The code is unchanged, but I tidied the documentation.
692    
693    4.  Inside a character class, PCRE always treated \R and \X as literals,
694        whereas Perl faults them if its -w option is set. I have changed PCRE so
695        that it faults them when PCRE_EXTRA is set.
696    
697    5.  Added support for \N, which always matches any character other than
698        newline. (It is the same as "." when PCRE_DOTALL is not set.)
699    
700    6.  When compiling pcregrep with newer versions of gcc which may have
701        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
702        declared with attribute warn_unused_result" were given. Just casting the
703        result to (void) does not stop the warnings; a more elaborate fudge is
704        needed. I've used a macro to implement this.
705    
706    7.  Minor change to pcretest.c to avoid a compiler warning.
707    
708    8.  Added four artifical Unicode properties to help with an option to make
709        \s etc use properties (see next item). The new properties are: Xan
710        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
711    
712    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
713        use Unicode properties. (*UCP) at the start of a pattern can be used to set
714        this option. Modified pcretest to add /W to test this facility. Added
715        REG_UCP to make it available via the POSIX interface.
716    
717    10. Added --line-buffered to pcregrep.
718    
719    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
720        studied, and the match started with a letter with a code point greater than
721        127 whose first byte was different to the first byte of the other case of
722        the letter, the other case of this starting letter was not recognized
723        (#976).
724    
725    12. If a pattern that was studied started with a repeated Unicode property
726        test, for example, \p{Nd}+, there was the theoretical possibility of
727        setting up an incorrect bitmap of starting bytes, but fortunately it could
728        not have actually happened in practice until change 8 above was made (it
729        added property types that matched character-matching opcodes).
730    
731    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
732        possible starting bytes for non-anchored patterns.
733    
734    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
735        \R, and also a number of cases that involve Unicode properties, both
736        explicit and implicit when PCRE_UCP is set.
737    
738    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
739        input, it could crash or give wrong results if characters with values
740        greater than 0xc0 were present in the subject string. (Detail: it assumed
741        UTF-8 input when processing these items.)
742    
743    16. Added a lot of (int) casts to avoid compiler warnings in systems where
744        size_t is 64-bit (#991).
745    
746    17. Added a check for running out of memory when PCRE is compiled with
747        --disable-stack-for-recursion (#990).
748    
749    18. If the last data line in a file for pcretest does not have a newline on
750        the end, a newline was missing in the output.
751    
752    19. The default pcre_chartables.c file recognizes only ASCII characters (values
753        less than 128) in its various bitmaps. However, there is a facility for
754        generating tables according to the current locale when PCRE is compiled. It
755        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
756        characters, are recognized by isspace() and therefore were getting set in
757        these tables, and indeed these tables seem to approximate to ISO 8859. This
758        caused a problem in UTF-8 mode when pcre_study() was used to create a list
759        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
760        which of course cannot start UTF-8 characters. I have changed the code so
761        that only real ASCII characters (less than 128) and the correct starting
762        bytes for UTF-8 encodings are set for characters greater than 127 when in
763        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
764        altogether.)
765    
766    20. Added the /T option to pcretest so as to be able to run tests with non-
767        standard character tables, thus making it possible to include the tests
768        used for 19 above in the standard set of tests.
769    
770    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
771        reference to a subpattern the other side of a comment that contains an
772        opening parenthesis caused either an internal compiling error, or a
773        reference to the wrong subpattern.
774    
775    
776    Version 8.02 19-Mar-2010
777    ------------------------
778    
779    1.  The Unicode data tables have been updated to Unicode 5.2.0.
780    
781    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
782        configured.
783    
784    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
785        original author of that file, following a query about its status.
786    
787    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
788        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
789    
790    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
791        quantifier applied to a forward-referencing subroutine call, could compile
792        incorrect code or give the error "internal error: previously-checked
793        referenced subpattern not found".
794    
795    6.  Both MS Visual Studio and Symbian OS have problems with initializing
796        variables to point to external functions. For these systems, therefore,
797        pcre_malloc etc. are now initialized to local functions that call the
798        relevant global functions.
799    
800    7.  There were two entries missing in the vectors called coptable and poptable
801        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
802        I've fixed the data, and added a kludgy way of testing at compile time that
803        the lengths are correct (equal to the number of opcodes).
804    
805    8.  Following on from 7, I added a similar kludge to check the length of the
806        eint vector in pcreposix.c.
807    
808    9.  Error texts for pcre_compile() are held as one long string to avoid too
809        much relocation at load time. To find a text, the string is searched,
810        counting zeros. There was no check for running off the end of the string,
811        which could happen if a new error number was added without updating the
812        string.
813    
814    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
815    
816    11. \K was not working if it appeared in an atomic group or in a group that
817        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
818        \K is "not well defined" if used in an assertion. PCRE now accepts it if
819        the assertion is positive, but not if it is negative.
820    
821    12. Change 11 fortuitously reduced the size of the stack frame used in the
822        "match()" function of pcre_exec.c by one pointer. Forthcoming
823        implementation of support for (*MARK) will need an extra pointer on the
824        stack; I have reserved it now, so that the stack frame size does not
825        decrease.
826    
827    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
828        item in branch that calls a recursion is a subroutine call - as in the
829        second branch in the above example - was incorrectly given the compile-
830        time error "recursive call could loop indefinitely" because pcre_compile()
831        was not correctly checking the subroutine for matching a non-empty string.
832    
833    14. The checks for overrunning compiling workspace could trigger after an
834        overrun had occurred. This is a "should never occur" error, but it can be
835        triggered by pathological patterns such as hundreds of nested parentheses.
836        The checks now trigger 100 bytes before the end of the workspace.
837    
838    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
839    
840    
841    Version 8.01 19-Jan-2010
842    ------------------------
843    
844    1.  If a pattern contained a conditional subpattern with only one branch (in
845        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
846        computed the wrong minimum data length (which is of course zero for such
847        subpatterns). This could cause incorrect "no match" results.
848    
849    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
850        the pattern is reset in the first branch, pcre_compile() failed with
851        "internal error: code overflow at offset...". This happened only when
852        the reset was to the original external option setting. (An optimization
853        abstracts leading options settings into an external setting, which was the
854        cause of this.)
855    
856    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
857        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
858        assertion pattern did not match (meaning that the assertion was true), it
859        was incorrectly treated as false if the SKIP had been reached during the
860        matching. This also applied to assertions used as conditions.
861    
862    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
863        assertion subpattern, including such a pattern used as a condition,
864        unpredictable results occurred, instead of the error return
865        PCRE_ERROR_DFA_UITEM.
866    
867    5.  The C++ GlobalReplace function was not working like Perl for the special
868        situation when an empty string is matched. It now does the fancy magic
869        stuff that is necessary.
870    
871    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
872        removed. (These were left over from very, very early versions of PCRE.)
873    
874    7.  Some cosmetic changes to the code to make life easier when compiling it
875        as part of something else:
876    
877        (a) Change DEBUG to PCRE_DEBUG.
878    
879        (b) In pcre_compile(), rename the member of the "branch_chain" structure
880            called "current" as "current_branch", to prevent a collision with the
881            Linux macro when compiled as a kernel module.
882    
883        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
884            prevent a collision with the Linux macro when compiled as a kernel
885            module.
886    
887    8.  In pcre_compile() there are some checks for integer overflows that used to
888        cast potentially large values to (double). This has been changed to that
889        when building, a check for int64_t is made, and if it is found, it is used
890        instead, thus avoiding the use of floating point arithmetic. (There is no
891        other use of FP in PCRE.) If int64_t is not found, the fallback is to
892        double.
893    
894    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
895        2005 (difference between two addresses compared to an unsigned value).
896    
897    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
898        custom one, because of the following reported problem in Windows:
899    
900          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
901              under Win32.
902          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
903              therefore missing the function definition.
904          - The compiler thus generates a "C" signature for the test function.
905          - The linker fails to find the "C" function.
906          - PCRE fails to configure if asked to do so against libbz2.
907    
908    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
909        messages were output:
910    
911          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
912          rerunning libtoolize, to keep the correct libtool macros in-tree.
913          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
914    
915        I have done both of these things.
916    
917    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
918        most of the time, it *can* run out if it is given a pattern that contains a
919        runaway infinite recursion. I updated the discussion in the pcrestack man
920        page.
921    
922    13. Now that we have gone to the x.xx style of version numbers, the minor
923        version may start with zero. Using 08 or 09 is a bad idea because users
924        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
925        interpreted as invalid octal numbers. I've updated the previous comment in
926        configure.ac, and also added a check that gives an error if 08 or 09 are
927        used.
928    
929    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
930        causing partial matching to fail when the end of the subject matched \W
931        in a UTF-8 pattern where \W was quantified with a minimum of 3.
932    
933    15. There were some discrepancies between the declarations in pcre_internal.h
934        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
935        their definitions. The declarations used "const uschar *" and the
936        definitions used USPTR. Even though USPTR is normally defined as "const
937        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
938        reported that: "This difference in casting confuses some C++ compilers, for
939        example, SunCC recognizes above declarations as different functions and
940        generates broken code for hbpcre." I have changed the declarations to use
941        USPTR.
942    
943    16. GNU libtool is named differently on some systems. The autogen.sh script now
944        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
945        (FreeBSD).
946    
947    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
948        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
949        comment: "Figure out how to create a longlong from a string: strtoll and
950        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
951        instance, but it only takes 2 args instead of 3!"
952    
953    18. A subtle bug concerned with back references has been fixed by a change of
954        specification, with a corresponding code fix. A pattern such as
955        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
956        refers, was giving matches when it shouldn't. For example, xa=xaaa would
957        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
958        same bug. Such groups have to be quantified to be useful, or contained
959        inside another quantified group. (If there's no repetition, the reference
960        can never match.) The problem arises because, having left the group and
961        moved on to the rest of the pattern, a later failure that backtracks into
962        the group uses the captured value from the final iteration of the group
963        rather than the correct earlier one. I have fixed this in PCRE by forcing
964        any group that contains a reference to itself to be an atomic group; that
965        is, there cannot be any backtracking into it once it has completed. This is
966        similar to recursive and subroutine calls.
967    
968    
969    Version 8.00 19-Oct-09
970    ----------------------
971    
972    1.  The table for translating pcre_compile() error codes into POSIX error codes
973        was out-of-date, and there was no check on the pcre_compile() error code
974        being within the table. This could lead to an OK return being given in
975        error.
976    
977    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
978        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
979        in a Windows environment.
980    
981    3.  The pcregrep --count option prints the count for each file even when it is
982        zero, as does GNU grep. However, pcregrep was also printing all files when
983        --files-with-matches was added. Now, when both options are given, it prints
984        counts only for those files that have at least one match. (GNU grep just
985        prints the file name in this circumstance, but including the count seems
986        more useful - otherwise, why use --count?) Also ensured that the
987        combination -clh just lists non-zero counts, with no names.
988    
989    4.  The long form of the pcregrep -F option was incorrectly implemented as
990        --fixed_strings instead of --fixed-strings. This is an incompatible change,
991        but it seems right to fix it, and I didn't think it was worth preserving
992        the old behaviour.
993    
994    5.  The command line items --regex=pattern and --regexp=pattern were not
995        recognized by pcregrep, which required --regex pattern or --regexp pattern
996        (with a space rather than an '='). The man page documented the '=' forms,
997        which are compatible with GNU grep; these now work.
998    
999    6.  No libpcreposix.pc file was created for pkg-config; there was just
1000        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1001    
1002    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1003        when UCP support is not needed, by modifying the Python script that
1004        generates it from Unicode data files. This should not matter if the module
1005        is correctly used as a library, but I received one complaint about 50K of
1006        unwanted data. My guess is that the person linked everything into his
1007        program rather than using a library. Anyway, it does no harm.
1008    
1009    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1010        was a minimum greater than 1 for a wide character in a possessive
1011        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1012        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1013        character. Chaos in the form of incorrect output or a compiling loop could
1014        result.
1015    
1016    9.  The restrictions on what a pattern can contain when partial matching is
1017        requested for pcre_exec() have been removed. All patterns can now be
1018        partially matched by this function. In addition, if there are at least two
1019        slots in the offset vector, the offset of the earliest inspected character
1020        for the match and the offset of the end of the subject are set in them when
1021        PCRE_ERROR_PARTIAL is returned.
1022    
1023    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1024        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1025        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1026        and may be more useful for multi-segment matching.
1027    
1028    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1029        used to be given if ever the end of the subject was reached; now it is
1030        given only if matching could not proceed because another character was
1031        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1032        string "Z", which now yields "no match" instead of "partial match". In the
1033        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1034        final character ended with (*FAIL).
1035    
1036    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1037        if the pattern had a "must contain" character that was already found in the
1038        earlier partial match, unless partial matching was again requested. For
1039        example, with the pattern /dog.(body)?/, the "must contain" character is
1040        "g". If the first part-match was for the string "dog", restarting with
1041        "sbody" failed. This bug has been fixed.
1042    
1043    13. The string returned by pcre_dfa_exec() after a partial match has been
1044        changed so that it starts at the first inspected character rather than the
1045        first character of the match. This makes a difference only if the pattern
1046        starts with a lookbehind assertion or \b or \B (\K is not supported by
1047        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1048        matching functions compatible, and I think it's the right thing to do.
1049    
1050    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1051        so that the demonstration program is easily available in environments where
1052        PCRE has not been installed from source.
1053    
1054    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1055        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1056        library.
1057    
1058    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1059        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1060        is not the first non-POSIX option to be added. Clearly some people find
1061        these options useful.
1062    
1063    17. If a caller to the POSIX matching function regexec() passes a non-zero
1064        value for nmatch with a NULL value for pmatch, the value of
1065        nmatch is forced to zero.
1066    
1067    18. RunGrepTest did not have a test for the availability of the -u option of
1068        the diff command, as RunTest does. It now checks in the same way as
1069        RunTest, and also checks for the -b option.
1070    
1071    19. If an odd number of negated classes containing just a single character
1072        interposed, within parentheses, between a forward reference to a named
1073        subpattern and the definition of the subpattern, compilation crashed with
1074        an internal error, complaining that it could not find the referenced
1075        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1076        [The bug was that it was starting one character too far in when skipping
1077        over the character class, thus treating the ] as data rather than
1078        terminating the class. This meant it could skip too much.]
1079    
1080    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1081        /g option in pcretest when the pattern contains \K, which makes it possible
1082        to have an empty string match not at the start, even when the pattern is
1083        anchored. Updated pcretest and pcredemo to use this option.
1084    
1085    21. If the maximum number of capturing subpatterns in a recursion was greater
1086        than the maximum at the outer level, the higher number was returned, but
1087        with unset values at the outer level. The correct (outer level) value is
1088        now given.
1089    
1090    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1091        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1092        make it do so. The string so far is captured, making this feature
1093        compatible with Perl.
1094    
1095    23. The tests have been re-organized, adding tests 11 and 12, to make it
1096        possible to check the Perl 5.10 features against Perl 5.10.
1097    
1098    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1099        pattern matches a fixed length string. PCRE did not allow this; now it
1100        does. Neither allows recursion.
1101    
1102    25. I finally figured out how to implement a request to provide the minimum
1103        length of subject string that was needed in order to match a given pattern.
1104        (It was back references and recursion that I had previously got hung up
1105        on.) This code has now been added to pcre_study(); it finds a lower bound
1106        to the length of subject needed. It is not necessarily the greatest lower
1107        bound, but using it to avoid searching strings that are too short does give
1108        some useful speed-ups. The value is available to calling programs via
1109        pcre_fullinfo().
1110    
1111    26. While implementing 25, I discovered to my embarrassment that pcretest had
1112        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1113        study optimizations had never been tested with that matching function.
1114        Oops. What is worse, even when it was passed study data, there was a bug in
1115        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1116        were also very few tests of studied patterns with pcre_dfa_exec().
1117    
1118    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1119        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1120        on the other side of the coin, they are no longer allowed to have different
1121        names, because these cannot be distinguished in PCRE, and this has caused
1122        confusion. (This is a difference from Perl.)
1123    
1124    28. When duplicate subpattern names are present (necessarily with different
1125        numbers, as required by 27 above), and a test is made by name in a
1126        conditional pattern, either for a subpattern having been matched, or for
1127        recursion in such a pattern, all the associated numbered subpatterns are
1128        tested, and the overall condition is true if the condition is true for any
1129        one of them. This is the way Perl works, and is also more like the way
1130        testing by number works.
1131    
1132    
1133    Version 7.9 11-Apr-09
1134    ---------------------
1135    
1136    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1137        (pcretest), all targets were linked against these libraries. This included
1138        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1139        libraries. This caused unwanted dependencies to be created. This problem
1140        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1141        pcretest is linked with readline.
1142    
1143    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1144        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1145        moved outside it again, because FALSE and TRUE are already defined in AIX,
1146        but BOOL is not.
1147    
1148    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1149        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1150    
1151    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1152        hyphens) following file names and line numbers when outputting matching
1153        lines. This is not true; no spaces are inserted. I have also clarified the
1154        wording for the --colour (or --color) option.
1155    
1156    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1157        was not coloured; this is different to GNU grep, so I have changed it to be
1158        the same.
1159    
1160    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1161        each matching line was coloured. Now it goes on to look for further matches
1162        of any of the test patterns, which is the same behaviour as GNU grep.
1163    
1164    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1165        doesn't make sense to accept an empty string match in pcregrep, so I have
1166        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1167        seems to be how GNU grep behaves.
1168    
1169    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1170        start or after a newline", because the conditional assertion was not being
1171        correctly handled. The rule now is that both the assertion and what follows
1172        in the first alternative must satisfy the test.
1173    
1174    9.  If auto-callout was enabled in a pattern with a conditional group whose
1175        condition was an assertion, PCRE could crash during matching, both with
1176        pcre_exec() and pcre_dfa_exec().
1177    
1178    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1179        used for matching.
1180    
1181    11. Unicode property support in character classes was not working for
1182        characters (bytes) greater than 127 when not in UTF-8 mode.
1183    
1184    12. Added the -M command line option to pcretest.
1185    
1186    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1187    
1188    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1189    
1190    16. Added comments and documentation about mis-use of no_arg in the C++
1191        wrapper.
1192    
1193    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1194        from Martin Jerabek that uses macro names for all relevant character and
1195        string constants.
1196    
1197    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1198        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1199        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1200        these, but not everybody uses configure.
1201    
1202    19. A conditional group that had only one branch was not being correctly
1203        recognized as an item that could match an empty string. This meant that an
1204        enclosing group might also not be so recognized, causing infinite looping
1205        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1206        with the subject "ab", where knowledge that the repeated group can match
1207        nothing is needed in order to break the loop.
1208    
1209    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1210        exec(), but without supplying a callout function, matching went wrong.
1211    
1212    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1213        leak if the size of the offset vector was greater than 30. When the vector
1214        is smaller, the saved offsets during recursion go onto a local stack
1215        vector, but for larger vectors malloc() is used. It was failing to free
1216        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1217        error, in fact).
1218    
1219    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1220        heapframe that is used only when UTF-8 support is enabled. This caused no
1221        problem, but was untidy.
1222    
1223    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1224        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1225        included within another project.
1226    
1227    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1228        slightly modified by me:
1229    
1230          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1231              not building pcregrep.
1232    
1233          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1234              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1235    
1236    25. Forward references, both numeric and by name, in patterns that made use of
1237        duplicate group numbers, could behave incorrectly or give incorrect errors,
1238        because when scanning forward to find the reference group, PCRE was not
1239        taking into account the duplicate group numbers. A pattern such as
1240        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1241    
1242    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1243        the feature of a custom pointer more persuasive (as requested by a user).
1244    
1245    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1246        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1247        pre-defined.
1248    
1249    28. Added support for (*UTF8) at the start of a pattern.
1250    
1251    29. Arrange for flags added by the "release type" setting in CMake to be shown
1252        in the configuration summary.
1253    
1254    
1255    Version 7.8 05-Sep-08
1256    ---------------------
1257    
1258    1.  Replaced UCP searching code with optimized version as implemented for Ad
1259        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1260        stage table and inline lookup instead of a function, giving speed ups of 2
1261        to 5 times on some simple patterns that I tested. Permission was given to
1262        distribute the MultiStage2.py script that generates the tables (it's not in
1263        the tarball, but is in the Subversion repository).
1264    
1265    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1266        scripts.
1267    
1268    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1269        a group with a zero qualifier. The result of the study could be incorrect,
1270        or the function might crash, depending on the pattern.
1271    
1272    4.  Caseless matching was not working for non-ASCII characters in back
1273        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1274        It now works when Unicode Property Support is available.
1275    
1276    5.  In pcretest, an escape such as \x{de} in the data was always generating
1277        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1278        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1279        truncation.
1280    
1281    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1282    
1283    7.  Added two (int) casts to pcregrep when printing the difference of two
1284        pointers, in case they are 64-bit values.
1285    
1286    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1287        test 2 if it fails.
1288    
1289    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1290        and a #define of that name to empty if it is not externally set. This is to
1291        allow users of MSVC to set it if necessary.
1292    
1293    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1294        the convenience functions in the pcre_get.c source file.
1295    
1296    11. An option change at the start of a pattern that had top-level alternatives
1297        could cause overwriting and/or a crash. This command provoked a crash in
1298        some environments:
1299    
1300          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1301    
1302        This potential security problem was recorded as CVE-2008-2371.
1303    
1304    12. For a pattern where the match had to start at the beginning or immediately
1305        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1306        pcre_dfa_exec() could read past the end of the passed subject if there was
1307        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1308        pcretest so that it places the subject at the end of its malloc-ed buffer.
1309    
1310    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1311        exec() might read past the end of the data buffer in UTF-8 mode.
1312    
1313    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1314        the data contained the byte 0x85 as part of a UTF-8 character within its
1315        first line. This applied both to normal and DFA matching.
1316    
1317    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1318        /^[^d]*?$/8 failed to match "abc".
1319    
1320    16. Added a missing copyright notice to pcrecpp_internal.h.
1321    
1322    17. Make it more clear in the documentation that values returned from
1323        pcre_exec() in ovector are byte offsets, not character counts.
1324    
1325    18. Tidied a few places to stop certain compilers from issuing warnings.
1326    
1327    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1328        supplied by Stefan Weber. I made a further small update for 7.8 because
1329        there is a change of source arrangements: the pcre_searchfuncs.c module is
1330        replaced by pcre_ucd.c.
1331    
1332    
1333    Version 7.7 07-May-08
1334    ---------------------
1335    
1336    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1337        a string to a long long, pretend we don't even have a long long." This is
1338        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1339    
1340    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1341        pre-7.6 versions, which defined a global no_arg variable instead of putting
1342        it in the RE class. (See also #8 below.)
1343    
1344    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1345        Lopes.
1346    
1347    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1348    
1349        (1) The include/exclude patterns were being applied to the whole pathnames
1350            of files, instead of just to the final components.
1351    
1352        (2) If there was more than one level of directory, the subdirectories were
1353            skipped unless they satisfied the include/exclude conditions. This is
1354            inconsistent with GNU grep (and could even be seen as contrary to the
1355            pcregrep specification - which I improved to make it absolutely clear).
1356            The action now is always to scan all levels of directory, and just
1357            apply the include/exclude patterns to regular files.
1358    
1359    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1360        --exclude_dir in the tests to avoid scanning .svn directories.
1361    
1362    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1363        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1364        doesn't support NULs in patterns.
1365    
1366    7.  Added some missing "const"s to declarations of static tables in
1367        pcre_compile.c and pcre_dfa_exec.c.
1368    
1369    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1370        caused by fix #2  above. (Subsequently also a second patch to fix the
1371        first patch. And a third patch - this was a messy problem.)
1372    
1373    9.  Applied Craig's patch to remove the use of push_back().
1374    
1375    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1376        matching function regexec().
1377    
1378    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1379        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1380        references. PCRE supports relative numbers with this syntax (I don't think
1381        Oniguruma does).
1382    
1383    12. Previously, a group with a zero repeat such as (...){0} was completely
1384        omitted from the compiled regex. However, this means that if the group
1385        was called as a subroutine from elsewhere in the pattern, things went wrong
1386        (an internal error was given). Such groups are now left in the compiled
1387        pattern, with a new opcode that causes them to be skipped at execution
1388        time.
1389    
1390    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1391        to the way PCRE behaves:
1392    
1393        (a) A lone ] character is dis-allowed (Perl treats it as data).
1394    
1395        (b) A back reference to an unmatched subpattern matches an empty string
1396            (Perl fails the current match path).
1397    
1398        (c) A data ] in a character class must be notated as \] because if the
1399            first data character in a class is ], it defines an empty class. (In
1400            Perl it is not possible to have an empty class.) The empty class []
1401            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1402            The negative empty class [^] matches any one character, independently
1403            of the DOTALL setting.
1404    
1405    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1406        non-existent subpattern following a character class starting with ']' and
1407        containing () gave an internal compiling error instead of "reference to
1408        non-existent subpattern". Fortunately, when the pattern did exist, the
1409        compiled code was correct. (When scanning forwards to check for the
1410        existencd of the subpattern, it was treating the data ']' as terminating
1411        the class, so got the count wrong. When actually compiling, the reference
1412        was subsequently set up correctly.)
1413    
1414    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1415        it was being rejected as not supported by pcre_dfa_exec(), even though
1416        other assertions are supported. I have made pcre_dfa_exec() support
1417        (*FAIL).
1418    
1419    16. The implementation of 13c above involved the invention of a new opcode,
1420        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1421        cannot be changed at match time, I realized I could make a small
1422        improvement to matching performance by compiling OP_ALLANY instead of
1423        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1424        on the OP_ANY path.
1425    
1426    17. Compiling pcretest on Windows with readline support failed without the
1427        following two fixes: (1) Make the unistd.h include conditional on
1428        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1429    
1430    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1431        ncurses library to be included for pcretest when ReadLine support is
1432        requested, but also to allow for it to be overridden. This patch came from
1433        Daniel Bergström.
1434    
1435    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1436        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1437        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1438        spotting this.
1439    
1440    
1441    Version 7.6 28-Jan-08
1442    ---------------------
1443    
1444    1.  A character class containing a very large number of characters with
1445        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1446        overflow.
1447    
1448    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1449        HAVE_LONG_LONG is not defined.
1450    
1451    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1452        bring them up to date and include new features. This patch includes:
1453    
1454        - Fixed PH's badly added libz and libbz2 support.
1455        - Fixed a problem with static linking.
1456        - Added pcredemo. [But later removed - see 7 below.]
1457        - Fixed dftables problem and added an option.
1458        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1459            HAVE_LONG_LONG.
1460        - Added readline support for pcretest.
1461        - Added an listing of the option settings after cmake has run.
1462    
1463    4.  A user submitted a patch to Makefile that makes it easy to create
1464        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1465        Makefile.am that cause it to include this special target, without
1466        affecting anything else. Note that the same mingw target plus all
1467        the other distribution libraries and programs are now supported
1468        when configuring with CMake (see 6 below) instead of with
1469        Configure/Make.
1470    
1471    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1472        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1473        exported in the Windows port". It has not yet been confirmed that the patch
1474        solves the problem, but it does no harm.
1475    
1476    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1477        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1478        with CMake, and also correct the comment about stack recursion.
1479    
1480    7.  Remove the automatic building of pcredemo from the ./configure system and
1481        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1482        of a program that users should build themselves after PCRE is installed, so
1483        building it automatically is not really right. What is more, it gave
1484        trouble in some build environments.
1485    
1486    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1487    
1488    
1489    Version 7.5 10-Jan-08
1490    ---------------------
1491    
1492    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1493        values in parens when parsing an RE using the C++ wrapper."
1494    
1495    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1496        Characters greater than 255 were excluded from the class instead of being
1497        included.
1498    
1499    3.  The same bug as (2) above applied to negated POSIX classes such as
1500        [:^space:].
1501    
1502    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1503        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1504        I have changed it.
1505    
1506    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1507        first named subpattern) and a construct such as (?&a) would reference the
1508        first named subpattern whose name started with "a" (in other words, the
1509        length check was missing). Both these problems are fixed. "Subpattern name
1510        expected" is now given for (?&) (a zero-length name), and this patch also
1511        makes it give the same error for \k'' (previously it complained that that
1512        was a reference to a non-existent subpattern).
1513    
1514    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1515        this is right because (?- can be followed by option settings as well as by
1516        digits. I have, however, made the messages clearer.
1517    
1518    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1519        than the number used in the conditional) now cause a compile-time error.
1520        This is actually not compatible with Perl, which accepts such patterns, but
1521        treats the conditional as always being FALSE (as PCRE used to), but it
1522        seems to me that giving a diagnostic is better.
1523    
1524    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1525        and messages.
1526    
1527    9.  Fix two occurrences of "backslash" in comments that should have been
1528        "backspace".
1529    
1530    10. Remove two redundant lines of code that can never be obeyed (their function
1531        was moved elsewhere).
1532    
1533    11. The program that makes PCRE's Unicode character property table had a bug
1534        which caused it to generate incorrect table entries for sequences of
1535        characters that have the same character type, but are in different scripts.
1536        It amalgamated them into a single range, with the script of the first of
1537        them. In other words, some characters were in the wrong script. There were
1538        thirteen such cases, affecting characters in the following ranges:
1539    
1540          U+002b0 - U+002c1
1541          U+0060c - U+0060d
1542          U+0061e - U+00612
1543          U+0064b - U+0065e
1544          U+0074d - U+0076d
1545          U+01800 - U+01805
1546          U+01d00 - U+01d77
1547          U+01d9b - U+01dbf
1548          U+0200b - U+0200f
1549          U+030fc - U+030fe
1550          U+03260 - U+0327f
1551          U+0fb46 - U+0fbb1
1552          U+10450 - U+1049d
1553    
1554    12. The -o option (show only the matching part of a line) for pcregrep was not
1555        compatible with GNU grep in that, if there was more than one match in a
1556        line, it showed only the first of them. It now behaves in the same way as
1557        GNU grep.
1558    
1559    13. If the -o and -v options were combined for pcregrep, it printed a blank
1560        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1561        does the same. The return code can be used to tell if there were any
1562        non-matching lines.
1563    
1564    14. Added --file-offsets and --line-offsets to pcregrep.
1565    
1566    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1567        infinitely looping recursion. The bug was that positive lookaheads were not
1568        being skipped when checking for a possible empty match (negative lookaheads
1569        and both kinds of lookbehind were skipped).
1570    
1571    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1572        inclusion of <windows.h> to before rather than after the definition of
1573        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1574    
1575    17. Specifying a possessive quantifier with a specific limit for a Unicode
1576        character property caused pcre_compile() to compile bad code, which led at
1577        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1578        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1579        caused the error; without that there was no problem.
1580    
1581    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1582    
1583    19. Added --enable-pcretest-libreadline.
1584    
1585    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1586        RE::GlobalReplace(). As a result, the number of replacements returned was
1587        double what it should be. I removed one of the increments, but Craig sent a
1588        later patch that removed the other one (the right fix) and added unit tests
1589        that check the return values (which was not done before).
1590    
1591    21. Several CMake things:
1592    
1593        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1594            the names libpcre and libpcreposix, not just pcre and pcreposix.
1595    
1596        (2) The above change means that pcretest and pcregrep are now correctly
1597            linked with the newly-built libraries, not previously installed ones.
1598    
1599        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1600    
1601    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1602        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1603        UTF-8 newline character). The key issue is that the pattern starts .*;
1604        this means that the match must be either at the beginning, or after a
1605        newline. The bug was in the code for advancing after a failed match and
1606        checking that the new position followed a newline. It was not taking
1607        account of UTF-8 characters correctly.
1608    
1609    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1610        character classes. PCRE was not treating the sequence [:...:] as a
1611        character class unless the ... were all letters. Perl, however, seems to
1612        allow any characters between [: and :], though of course it rejects as
1613        unknown any "names" that contain non-letters, because all the known class
1614        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1615        for example, whereas PCRE did not - it did not recognize a POSIX character
1616        class. This seemed a bit dangerous, so the code has been changed to be
1617        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1618        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1619        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1620        Perl does, and where it didn't before.
1621    
1622    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1623        Windows environments %n is disabled by default.
1624    
1625    
1626    Version 7.4 21-Sep-07
1627    ---------------------
1628    
1629    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1630        means that a class such as [\s] counted as "explicit reference to CR or
1631        LF". That isn't really right - the whole point of the change was to try to
1632        help when there was an actual mention of one of the two characters. So now
1633        the change happens only if \r or \n (or a literal CR or LF) character is
1634        encountered.
1635    
1636    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1637        of both had grown to the point where there were only 3 bits left.
1638        Fortunately, there was spare space in the data structure, and so I have
1639        moved the internal flags into a new 16-bit field to free up more option
1640        bits.
1641    
1642    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1643        but did not set the internal JCHANGED flag - either of these is enough to
1644        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1645        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1646        start sets both bits.
1647    
1648    4.  Added options (at build time, compile time, exec time) to change \R from
1649        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1650    
1651    5.  doc/pcresyntax.html was missing from the distribution.
1652    
1653    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1654        compatibility, even though it is no longer used.
1655    
1656    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1657        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1658        windows.h file is present (where different names are used). [This was
1659        reversed later after testing - see 16 below.]
1660    
1661    8.  Changed all #include <config.h> to #include "config.h". There were also
1662        some further <pcre.h> cases that I changed to "pcre.h".
1663    
1664    9.  When pcregrep was used with the --colour option, it missed the line ending
1665        sequence off the lines that it output.
1666    
1667    10. It was pointed out to me that arrays of string pointers cause lots of
1668        relocations when a shared library is dynamically loaded. A technique of
1669        using a single long string with a table of offsets can drastically reduce
1670        these. I have refactored PCRE in four places to do this. The result is
1671        dramatic:
1672    
1673          Originally:                          290
1674          After changing UCP table:            187
1675          After changing error message table:   43
1676          After changing table of "verbs"       36
1677          After changing table of Posix names   22
1678    
1679        Thanks to the folks working on Gregex for glib for this insight.
1680    
1681    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1682        unicode-properties was also set.
1683    
1684    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1685    
1686    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1687        checked only for CRLF.
1688    
1689    14. Added casts to pcretest.c to avoid compiler warnings.
1690    
1691    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1692    
1693    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1694        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1695        entirely. This removes changes made in 7 above.
1696    
1697    17. The CMake files have been updated, and there is now more information about
1698        building with CMake in the NON-UNIX-USE document.
1699    
1700    
1701    Version 7.3 28-Aug-07
1702    ---------------------
1703    
1704     1. In the rejigging of the build system that eventually resulted in 7.1, the
1705        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1706        brackets there is not right, since it causes compilers to look for an
1707        installed pcre.h, not the version that is in the source that is being
1708        compiled (which of course may be different). I have changed it back to:
1709    
1710          #include "pcre.h"
1711    
1712        I have a vague recollection that the change was concerned with compiling in
1713        different directories, but in the new build system, that is taken care of
1714        by the VPATH setting the Makefile.
1715    
1716     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1717        when the subject happened to end in the byte 0x85 (e.g. if the last
1718        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1719        characters but of course it shouldn't be taken as a newline when it is part
1720        of another character. The bug was that, for an unlimited repeat of . in
1721        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1722        characters when looking for a newline.
1723    
1724     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1725    
1726     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1727        in debug output.
1728    
1729     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1730        long printing in the pcrecpp unittest when running under MinGW.
1731    
1732     6. ESC_K was left out of the EBCDIC table.
1733    
1734     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1735        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1736        limit also applies to "virtual nesting" when a pattern is recursive, and in
1737        this case 1000 isn't so big. I have been able to remove this limit at the
1738        expense of backing off one optimization in certain circumstances. Normally,
1739        when pcre_exec() would call its internal match() function recursively and
1740        immediately return the result unconditionally, it uses a "tail recursion"
1741        feature to save stack. However, when a subpattern that can match an empty
1742        string has an unlimited repetition quantifier, it no longer makes this
1743        optimization. That gives it a stack frame in which to save the data for
1744        checking that an empty string has been matched. Previously this was taken
1745        from the 1000-entry workspace that had been reserved. So now there is no
1746        explicit limit, but more stack is used.
1747    
1748     8. Applied Daniel's patches to solve problems with the import/export magic
1749        syntax that is required for Windows, and which was going wrong for the
1750        pcreposix and pcrecpp parts of the library. These were overlooked when this
1751        problem was solved for the main library.
1752    
1753     9. There were some crude static tests to avoid integer overflow when computing
1754        the size of patterns that contain repeated groups with explicit upper
1755        limits. As the maximum quantifier is 65535, the maximum group length was
1756        set at 30,000 so that the product of these two numbers did not overflow a
1757        32-bit integer. However, it turns out that people want to use groups that
1758        are longer than 30,000 bytes (though not repeat them that many times).
1759        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1760        made it possible to implement the integer overflow checks in a much more
1761        dynamic way, which I have now done. The artificial limitation on group
1762        length has been removed - we now have only the limit on the total length of
1763        the compiled pattern, which depends on the LINK_SIZE setting.
1764    
1765    10. Fixed a bug in the documentation for get/copy named substring when
1766        duplicate names are permitted. If none of the named substrings are set, the
1767        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1768        empty string.
1769    
1770    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1771        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1772        because the ] is interpreted as the first data character and the
1773        terminating ] is not found. PCRE has been made compatible with Perl in this
1774        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1775        cause memory overwriting.
1776    
1777    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1778        string has been matched (to stop an infinite loop). It was not recognizing
1779        a conditional subpattern that could match an empty string if that
1780        subpattern was within another subpattern. For example, it looped when
1781        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1782        condition was not nested. This bug has been fixed.
1783    
1784    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1785        past the start of the subject in the presence of bytes with the top bit
1786        set, for example "\x8aBCD".
1787    
1788    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1789        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1790    
1791    14. Optimized (?!) to (*FAIL).
1792    
1793    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1794        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1795        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1796        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1797        does: it's just the validity check that is more restrictive.
1798    
1799    16. Inserted checks for integer overflows during escape sequence (backslash)
1800        processing, and also fixed erroneous offset values for syntax errors during
1801        backslash processing.
1802    
1803    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1804        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1805    
1806    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1807        caused an overrun.
1808    
1809    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1810        something other than just ASCII characters) inside a group that had an
1811        unlimited repeat caused a loop at compile time (while checking to see
1812        whether the group could match an empty string).
1813    
1814    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1815        [\P{Any}] did so. (Error in the code for printing property names.)
1816    
1817    21. An orphan \E inside a character class could cause a crash.
1818    
1819    22. A repeated capturing bracket such as (A)? could cause a wild memory
1820        reference during compilation.
1821    
1822    23. There are several functions in pcre_compile() that scan along a compiled
1823        expression for various reasons (e.g. to see if it's fixed length for look
1824        behind). There were bugs in these functions when a repeated \p or \P was
1825        present in the pattern. These operators have additional parameters compared
1826        with \d, etc, and these were not being taken into account when moving along
1827        the compiled data. Specifically:
1828    
1829        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1830            length.
1831    
1832        (b) An item such as \pL+ within a repeated group could cause crashes or
1833            loops.
1834    
1835        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1836            "reference to non-existent subpattern" error.
1837    
1838        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1839    
1840    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1841        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1842    
1843    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1844    
1845    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1846        character were causing crashes (broken optimization).
1847    
1848    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1849        \p or \P) caused a compile-time loop.
1850    
1851    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1852        break. For example, the unstudied pattern [\r\n]A does not match the string
1853        "\r\nA" because change 7.0/46 below moves the current point on by two
1854        characters after failing to match at the start. However, the pattern \nA
1855        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1856        the same is true. There doesn't seem any very clean way out of this, but
1857        what I have chosen to do makes the common cases work: PCRE now takes note
1858        of whether there can be an explicit match for \r or \n anywhere in the
1859        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1860        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1861        pattern has explicit CR or LF references.
1862    
1863    29. Added (*CR) etc for changing newline setting at start of pattern.
1864    
1865    
1866    Version 7.2 19-Jun-07
1867    ---------------------
1868    
1869     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1870        which is apparently normally available under Windows.
1871    
1872     2. Re-jig the pcregrep tests with different newline settings in an attempt
1873        to make them independent of the local environment's newline setting.
1874    
1875     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1876    
1877     4. Some of the "internals" tests were previously cut out when the link size
1878        was not 2, because the output contained actual offsets. The recent new
1879        "Z" feature of pcretest means that these can be cut out, making the tests
1880        usable with all link sizes.
1881    
1882     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1883        stack recursion. This gives a massive performance boost under BSD, but just
1884        a small improvement under Linux. However, it saves one field in the frame
1885        in all cases.
1886    
1887     6. Added more features from the forthcoming Perl 5.10:
1888    
1889        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1890            recursion call. It refers to the nth most recently opened parentheses.
1891    
1892        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1893            to be opened parentheses.
1894    
1895        (c) Conditions that refer to capturing parentheses can be specified
1896            relatively, for example, (?(-2)... or (?(+3)...
1897    
1898        (d) \K resets the start of the current match so that everything before
1899            is not part of it.
1900    
1901        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1902    
1903        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1904            reference syntax.
1905    
1906        (g) (?| introduces a group in which the numbering of parentheses in each
1907            alternative starts with the same number.
1908    
1909        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1910    
1911     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1912        PCRE_INFO_JCHANGED.
1913    
1914     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1915        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1916        for detecting groups that can match an empty string.
1917    
1918     9. A pattern with a very large number of alternatives (more than several
1919        hundred) was running out of internal workspace during the pre-compile
1920        phase, where pcre_compile() figures out how much memory will be needed. A
1921        bit of new cunning has reduced the workspace needed for groups with
1922        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1923        workspace instead of running out of the 4096 that are available.
1924    
1925    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1926    
1927    11. Applied patch from Google to remove an optimization that didn't quite work.
1928        The report of the bug said:
1929    
1930          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1931          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1932          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1933    
1934    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1935        it matched the wrong number of bytes.
1936    
1937    
1938    Version 7.1 24-Apr-07
1939  ---------------------  ---------------------
1940    
1941   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one

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