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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.9 xx-xxx-09  Version 8.30
5    ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
11        only in quite long subpatterns.
12    
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
15    
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
20    
21    5.  A reference to an unset group with zero minimum repetition was giving
22        totally wrong answers (in non-JavaScript-compatibility mode). For example,
23        /(another)?(\1?)test/ matched against "hello world test". This bug was
24        introduced in release 8.13.
25    
26    6.  Add support for 16-bit character strings (a large amount of work involving
27        many changes and refactorings).
28    
29    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31        from a file.
32    
33    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34        rounding is not applied in this particular case).
35    
36    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
38    
39    10. Get rid of a number of -Wunused-but-set-variable warnings.
40    
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses. It also applied to some
46        assertions.
47    
48    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49        information out of configure.ac instead of relying on pcre.h.generic, which
50        is not stored in the repository.
51    
52    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53        -lreadline.
54    
55    14. ZH added PCRE_CONFIG_JITTARGET; added it's output to pcretest -C.
56    
57    
58    Version 8.21 12-Dec-2011
59    ------------------------
60    
61    1.  Updating the JIT compiler.
62    
63    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
64        are added as well.
65    
66    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
67        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
68        calling _pcre_jit_exec. Some extra comments are added.
69    
70    4.  (*MARK) settings inside atomic groups that do not contain any capturing
71        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
72        was introduced by change 18 for 8.20.
73    
74    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
75        ECMA-262 standard.
76    
77    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
78        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
79        This bug was probably introduced by change 9 of 8.13.
80    
81    7.  While fixing 6 above, I noticed that a number of other items were being
82        incorrectly rejected as "not fixed length". This arose partly because newer
83        opcodes had not been added to the fixed-length checking code. I have (a)
84        corrected the bug and added tests for these items, and (b) arranged for an
85        error to occur if an unknown opcode is encountered while checking for fixed
86        length instead of just assuming "not fixed length". The items that were
87        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
88        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
89        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
90    
91    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
92        being incorrectly compiled and would have given unpredicatble results.
93    
94    9.  A possessively repeated subpattern with minimum repeat count greater than
95        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
96        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
97        the first (A) could occur when it should not.
98    
99    10. Add a cast and remove a redundant test from the code.
100    
101    11. JIT should use pcre_malloc/pcre_free for allocation.
102    
103    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
104        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
105        is anything other than /usr, -L is still shown).
106    
107    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
108    
109    14. Perl does not support \N without a following name in a [] class; PCRE now
110        also gives an error.
111    
112    15. If a forward reference was repeated with an upper limit of around 2000,
113        it caused the error "internal error: overran compiling workspace". The
114        maximum number of forward references (including repeats) was limited by the
115        internal workspace, and dependent on the LINK_SIZE. The code has been
116        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
117        the default depends on LINK_SIZE. There is a new upper limit (for safety)
118        of around 200,000 forward references. While doing this, I also speeded up
119        the filling in of repeated forward references.
120    
121    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
122        incorrectly expecting the subject to contain another "a" after the start.
123    
124    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
125        in the match, the SKIP should be ignored. This was not happening; instead
126        the SKIP was being treated as NOMATCH. For patterns such as
127        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
128        tested.
129    
130    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
131        now much more compatible with Perl, in particular in cases where the result
132        is a non-match for a non-anchored pattern. For example, if
133        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
134        "m", where previously it did not return a name. A side effect of this
135        change is that for partial matches, the last encountered mark name is
136        returned, as for non matches. A number of tests that were previously not
137        Perl-compatible have been moved into the Perl-compatible test files. The
138        refactoring has had the pleasing side effect of removing one argument from
139        the match() function, thus reducing its stack requirements.
140    
141    19. If the /S+ option was used in pcretest to study a pattern using JIT,
142        subsequent uses of /S (without +) incorrectly behaved like /S+.
143    
144    21. Retrieve executable code size support for the JIT compiler and fixing
145        some warnings.
146    
147    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
148        not work when the shorter character appeared right at the end of the
149        subject string.
150    
151    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
152        systems.
153    
154    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
155        output it when the /M option is used in pcretest.
156    
157    25. The CheckMan script was not being included in the distribution. Also, added
158        an explicit "perl" to run Perl scripts from the PrepareRelease script
159        because this is reportedly needed in Windows.
160    
161    26. If study data was being save in a file and studying had not found a set of
162        "starts with" bytes for the pattern, the data written to the file (though
163        never used) was taken from uninitialized memory and so caused valgrind to
164        complain.
165    
166    27. Updated RunTest.bat as provided by Sheri Pierce.
167    
168    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
169    
170    29. Computation of memory usage for the table of capturing group names was
171        giving an unnecessarily large value.
172    
173    
174    Version 8.20 21-Oct-2011
175    ------------------------
176    
177    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
178        a POSIX class. After further experiments with Perl, which convinced me that
179        Perl has bugs and confusions, a closing square bracket is no longer allowed
180        in a POSIX name. This bug also affected patterns with classes that started
181        with full stops.
182    
183    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
184        captured substring, but while checking the failing first alternative,
185        substring 1 is temporarily captured. If the output vector supplied to
186        pcre_exec() was not big enough for this capture, the yield of the function
187        was still zero ("insufficient space for captured substrings"). This cannot
188        be totally fixed without adding another stack variable, which seems a lot
189        of expense for a edge case. However, I have improved the situation in cases
190        such as /(a)(b)x|abc/ matched against "abc", where the return code
191        indicates that fewer than the maximum number of slots in the ovector have
192        been set.
193    
194    3.  Related to (2) above: when there are more back references in a pattern than
195        slots in the output vector, pcre_exec() uses temporary memory during
196        matching, and copies in the captures as far as possible afterwards. It was
197        using the entire output vector, but this conflicts with the specification
198        that only 2/3 is used for passing back captured substrings. Now it uses
199        only the first 2/3, for compatibility. This is, of course, another edge
200        case.
201    
202    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
203        main code base, and can be used by building with --enable-jit. When this is
204        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
205        runtime --no-jit option is given.
206    
207    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
208        ovector, the return from the function was zero, implying that there were
209        other matches that did not fit. The correct "exactly full" value is now
210        returned.
211    
212    6.  If a subpattern that was called recursively or as a subroutine contained
213        (*PRUNE) or any other control that caused it to give a non-standard return,
214        invalid errors such as "Error -26 (nested recursion at the same subject
215        position)" or even infinite loops could occur.
216    
217    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
218        computing the minimum length on reaching *ACCEPT, and so ended up with the
219        wrong value of 1 rather than 0. Further investigation indicates that
220        computing a minimum subject length in the presence of *ACCEPT is difficult
221        (think back references, subroutine calls), and so I have changed the code
222        so that no minimum is registered for a pattern that contains *ACCEPT.
223    
224    8.  If (*THEN) was present in the first (true) branch of a conditional group,
225        it was not handled as intended. [But see 16 below.]
226    
227    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
228        Sheri Pierce.
229    
230    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
231        the first byte in a match must be "a".
232    
233    11. Change 17 for 8.13 increased the recursion depth for patterns like
234        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
235        pattern contains any instances of (*THEN). If it does not, the old
236        optimizations are restored. It would be nice to do this on a per-group
237        basis, but at the moment that is not feasible.
238    
239    12. In some environments, the output of pcretest -C is CRLF terminated. This
240        broke RunTest's code that checks for the link size. A single white space
241        character after the value is now allowed for.
242    
243    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
244        For "fr", it uses the Windows-specific input and output files.
245    
246    14. If (*THEN) appeared in a group that was called recursively or as a
247        subroutine, it did not work as intended. [But see next item.]
248    
249    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
250        pattern fragments (but not containing any | characters). If A and B are
251        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
252        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
253        D. In other words, Perl considers parentheses that do not contain any |
254        characters to be part of a surrounding alternative, whereas PCRE was
255        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
256        differently. PCRE now behaves in the same way as Perl, except in the case
257        of subroutine/recursion calls such as (?1) which have in any case always
258        been different (but PCRE had them first :-).
259    
260    16. Related to 15 above: Perl does not treat the | in a conditional group as
261        creating alternatives. Such a group is treated in the same way as an
262        ordinary group without any | characters when processing (*THEN). PCRE has
263        been changed to match Perl's behaviour.
264    
265    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
266        RunGrepTest script failed.
267    
268    18. Change 22 for version 13 caused atomic groups to use more stack. This is
269        inevitable for groups that contain captures, but it can lead to a lot of
270        stack use in large patterns. The old behaviour has been restored for atomic
271        groups that do not contain any capturing parentheses.
272    
273    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
274        suppress the check for a minimum subject length at run time. (If it was
275        given to pcre_exec() or pcre_dfa_exec() it did work.)
276    
277    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
278        fail to work when decoding hex characters in data strings in EBCDIC
279        environments.
280    
281    21. It appears that in at least one Mac OS environment, the isxdigit() function
282        is implemented as a macro that evaluates to its argument more than once,
283        contravening the C 90 Standard (I haven't checked a later standard). There
284        was an instance in pcretest which caused it to go wrong when processing
285        \x{...} escapes in subject strings. The has been rewritten to avoid using
286        things like p++ in the argument of isxdigit().
287    
288    
289    Version 8.13 16-Aug-2011
290    ------------------------
291    
292    1.  The Unicode data tables have been updated to Unicode 6.0.0.
293    
294    2.  Two minor typos in pcre_internal.h have been fixed.
295    
296    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
297        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
298        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
299    
300    4.  There were a number of related bugs in the code for matching backrefences
301        caselessly in UTF-8 mode when codes for the characters concerned were
302        different numbers of bytes. For example, U+023A and U+2C65 are an upper
303        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
304        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
305        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
306        2-byte code at the end of the subject (it thought there wasn't enough data
307        left).
308    
309    5.  Comprehensive information about what went wrong is now returned by
310        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
311        as the output vector has at least 2 elements. The offset of the start of
312        the failing character and a reason code are placed in the vector.
313    
314    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
315        now returned is for the first byte of the failing character, instead of the
316        last byte inspected. This is an incompatible change, but I hope it is small
317        enough not to be a problem. It makes the returned offset consistent with
318        pcre_exec() and pcre_dfa_exec().
319    
320    7.  pcretest now gives a text phrase as well as the error number when
321        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
322        failure, the offset and reason code are output.
323    
324    8.  When \R was used with a maximizing quantifier it failed to skip backwards
325        over a \r\n pair if the subsequent match failed. Instead, it just skipped
326        back over a single character (\n). This seems wrong (because it treated the
327        two characters as a single entity when going forwards), conflicts with the
328        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
329        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
330        has been changed.
331    
332    9.  Some internal refactoring has changed the processing so that the handling
333        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
334        time (the PCRE_DOTALL option was changed this way some time ago: version
335        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
336        which was always a bit of a fudge. It also means that there is one less
337        argument for the match() function, which reduces its stack requirements
338        slightly. This change also fixes an incompatibility with Perl: the pattern
339        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
340    
341    10. More internal refactoring has drastically reduced the number of recursive
342        calls to match() for possessively repeated groups such as (abc)++ when
343        using pcre_exec().
344    
345    11. While implementing 10, a number of bugs in the handling of groups were
346        discovered and fixed:
347    
348        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
349        (a|)*(?1) gave a compile-time internal error.
350        ((a|)+)+  did not notice that the outer group could match an empty string.
351        (^a|^)+   was not marked as anchored.
352        (.*a|.*)+ was not marked as matching at start or after a newline.
353    
354    12. Yet more internal refactoring has removed another argument from the match()
355        function. Special calls to this function are now indicated by setting a
356        value in a variable in the "match data" data block.
357    
358    13. Be more explicit in pcre_study() instead of relying on "default" for
359        opcodes that mean there is no starting character; this means that when new
360        ones are added and accidentally left out of pcre_study(), testing should
361        pick them up.
362    
363    14. The -s option of pcretest has been documented for ages as being an old
364        synonym of -m (show memory usage). I have changed it to mean "force study
365        for every regex", that is, assume /S for every regex. This is similar to -i
366        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
367        using it. It makes it easier to run collections of tests with and without
368        study enabled, and thereby test pcre_study() more easily. All the standard
369        tests are now run with and without -s (but some patterns can be marked as
370        "never study" - see 20 below).
371    
372    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
373        restoration of the capturing data to the outer values was not happening
374        correctly.
375    
376    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
377        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
378        pattern had matched an empty string, and so incorrectly returned a no
379        match.
380    
381    17. There was optimizing code for the last branch of non-capturing parentheses,
382        and also for the obeyed branch of a conditional subexpression, which used
383        tail recursion to cut down on stack usage. Unfortunately, now that there is
384        the possibility of (*THEN) occurring in these branches, tail recursion is
385        no longer possible because the return has to be checked for (*THEN). These
386        two optimizations have therefore been removed. [But see 8.20/11 above.]
387    
388    18. If a pattern containing \R was studied, it was assumed that \R always
389        matched two bytes, thus causing the minimum subject length to be
390        incorrectly computed because \R can also match just one byte.
391    
392    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
393        was incorrectly computed.
394    
395    20. If /S is present twice on a test pattern in pcretest input, it now
396        *disables* studying, thereby overriding the use of -s on the command line
397        (see 14 above). This is necessary for one or two tests to keep the output
398        identical in both cases.
399    
400    21. When (*ACCEPT) was used in an assertion that matched an empty string and
401        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
402    
403    22. When an atomic group that contained a capturing parenthesis was
404        successfully matched, but the branch in which it appeared failed, the
405        capturing was not being forgotten if a higher numbered group was later
406        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
407        group 1 to "a", when in fact it should be unset. This applied to multi-
408        branched capturing and non-capturing groups, repeated or not, and also to
409        positive assertions (capturing in negative assertions does not happen
410        in PCRE) and also to nested atomic groups.
411    
412    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
413        subject after a captured substring, to make it easier to tell which of a
414        number of identical substrings has been captured.
415    
416    24. The way atomic groups are processed by pcre_exec() has been changed so that
417        if they are repeated, backtracking one repetition now resets captured
418        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
419        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
420        "aaa". Previously, it would have been "a". As part of this code
421        refactoring, the way recursive calls are handled has also been changed.
422    
423    25. If an assertion condition captured any substrings, they were not passed
424        back unless some other capturing happened later. For example, if
425        (?(?=(a))a) was matched against "a", no capturing was returned.
426    
427    26. When studying a pattern that contained subroutine calls or assertions,
428        the code for finding the minimum length of a possible match was handling
429        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
430        group 1 called group 2 while simultaneously a separate group 2 called group
431        1). A stack overflow occurred in this case. I have fixed this by limiting
432        the recursion depth to 10.
433    
434    27. Updated RunTest.bat in the distribution to the version supplied by Tom
435        Fortmann. This supports explicit test numbers on the command line, and has
436        argument validation and error reporting.
437    
438    28. An instance of \X with an unlimited repeat could fail if at any point the
439        first character it looked at was a mark character.
440    
441    29. Some minor code refactoring concerning Unicode properties and scripts
442        should reduce the stack requirement of match() slightly.
443    
444    30. Added the '=' option to pcretest to check the setting of unused capturing
445        slots at the end of the pattern, which are documented as being -1, but are
446        not included in the return count.
447    
448    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
449        compiled something random. Now it gives a compile-time error (as does
450        Perl).
451    
452    32. A *MARK encountered during the processing of a positive assertion is now
453        recorded and passed back (compatible with Perl).
454    
455    33. If --only-matching or --colour was set on a pcregrep call whose pattern
456        had alternative anchored branches, the search for a second match in a line
457        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
458        matched the line "0102" twice. The same bug affected patterns that started
459        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
460        twice.
461    
462    34. Previously, PCRE did not allow quantification of assertions. However, Perl
463        does, and because of capturing effects, quantifying parenthesized
464        assertions may at times be useful. Quantifiers are now allowed for
465        parenthesized assertions.
466    
467    35. A minor code tidy in pcre_compile() when checking options for \R usage.
468    
469    36. \g was being checked for fancy things in a character class, when it should
470        just be a literal "g".
471    
472    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
473        appearance of a nested POSIX class supersedes an apparent external class.
474        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
475        unescaped square brackets may also appear as part of class names. For
476        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
477        more like Perl. (But see 8.20/1 above.)
478    
479    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
480        was because it thought it was \N{name}, which is not supported).
481    
482    39. Add minix to OS list not supporting the -S option in pcretest.
483    
484    40. PCRE tries to detect cases of infinite recursion at compile time, but it
485        cannot analyze patterns in sufficient detail to catch mutual recursions
486        such as ((?1))((?2)). There is now a runtime test that gives an error if a
487        subgroup is called recursively as a subpattern for a second time at the
488        same position in the subject string. In previous releases this might have
489        been caught by the recursion limit, or it might have run out of stack.
490    
491    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
492        happen only once. PCRE was, however incorrectly giving a compile time error
493        "recursive call could loop indefinitely" because it cannot analyze the
494        pattern in sufficient detail. The compile time test no longer happens when
495        PCRE is compiling a conditional subpattern, but actual runaway loops are
496        now caught at runtime (see 40 above).
497    
498    42. It seems that Perl allows any characters other than a closing parenthesis
499        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
500        has been changed to be the same.
501    
502    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
503        as not to get warnings when autogen.sh is called. Also changed
504        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
505    
506    44. To help people who use pcregrep to scan files containing exceedingly long
507        lines, the following changes have been made:
508    
509        (a) The default value of the buffer size parameter has been increased from
510            8K to 20K. (The actual buffer used is three times this size.)
511    
512        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
513            PCRE is built.
514    
515        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
516            to be set at run time.
517    
518        (d) Numerical values in pcregrep options can be followed by K or M, for
519            example --buffer-size=50K.
520    
521        (e) If a line being scanned overflows pcregrep's buffer, an error is now
522            given and the return code is set to 2.
523    
524    45. Add a pointer to the latest mark to the callout data block.
525    
526    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
527        partial match of an empty string instead of no match. This was specific to
528        the use of ".".
529    
530    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
531        complete match instead of a partial match. This bug was dependent on both
532        the PCRE_UTF8 and PCRE_DOTALL options being set.
533    
534    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
535        starting byte set, because \b was not being ignored.
536    
537    
538    Version 8.12 15-Jan-2011
539    ------------------------
540    
541    1.  Fixed some typos in the markup of the man pages, and wrote a script that
542        checks for such things as part of the documentation building process.
543    
544    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
545        --match-limit and --recursion-limit options (added for 8.11). In
546        particular, this made one of the standard tests fail. (The integer value
547        went into the wrong half of a long int.)
548    
549    3.  If the --colour option was given to pcregrep with -v (invert match), it
550        did strange things, either producing crazy output, or crashing. It should,
551        of course, ignore a request for colour when reporting lines that do not
552        match.
553    
554    4.  Another pcregrep bug caused similar problems if --colour was specified with
555        -M (multiline) and the pattern match finished with a line ending.
556    
557    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
558        matched in multiline mode, the following line was shown as part of the
559        match. This seems wrong, so I have changed it.
560    
561    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
562        the check for further matches in the same line (so they could be coloured)
563        to overrun the end of the current line. If another match was found, it was
564        incorrectly shown (and then shown again when found in the next line).
565    
566    7.  If pcregrep was compiled under Windows, there was a reference to the
567        function pcregrep_exit() before it was defined. I am assuming this was
568        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
569        reported by a user. I've moved the definition above the reference.
570    
571    
572    Version 8.11 10-Dec-2010
573    ------------------------
574    
575    1.  (*THEN) was not working properly if there were untried alternatives prior
576        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
577        backtracked to try for "b" instead of moving to the next alternative branch
578        at the same level (in this case, to look for "c"). The Perl documentation
579        is clear that when (*THEN) is backtracked onto, it goes to the "next
580        alternative in the innermost enclosing group".
581    
582    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
583        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
584        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
585        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
586        (*THEN).
587    
588    3.  If \s appeared in a character class, it removed the VT character from
589        the class, even if it had been included by some previous item, for example
590        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
591        of \s, but is part of the POSIX "space" class.)
592    
593    4.  A partial match never returns an empty string (because you can always
594        match an empty string at the end of the subject); however the checking for
595        an empty string was starting at the "start of match" point. This has been
596        changed to the "earliest inspected character" point, because the returned
597        data for a partial match starts at this character. This means that, for
598        example, /(?<=abc)def/ gives a partial match for the subject "abc"
599        (previously it gave "no match").
600    
601    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
602        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
603        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
604        has an implication that the given string is incomplete (because a partial
605        match is preferred over a full match). For this reason, these items now
606        give a partial match in this situation. [Aside: previously, the one case
607        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
608        match rather than a full match, which was wrong by the old rules, but is
609        now correct.]
610    
611    6.  There was a bug in the handling of #-introduced comments, recognized when
612        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
613        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
614        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
615        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
616        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
617        places in pcre_compile().
618    
619    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
620        comments when looking ahead for named forward references to subpatterns,
621        the only newline sequence it recognized was NL. It now handles newlines
622        according to the set newline convention.
623    
624    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
625        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
626        cater for a lack of strerror(). These oversights have been fixed.
627    
628    9.  Added --match-limit and --recursion-limit to pcregrep.
629    
630    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
631    
632    11. When the -o option was used, pcregrep was setting a return code of 1, even
633        when matches were found, and --line-buffered was not being honoured.
634    
635    12. Added an optional parentheses number to the -o and --only-matching options
636        of pcregrep.
637    
638    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
639        can match an empty string. The code to do it in pcretest and pcredemo
640        needed fixing:
641    
642        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
643            only one byte after an empty string match just before CRLF (this case
644            just got forgotten; "any" and "anycrlf" were OK).
645    
646        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
647            mode when an empty string match preceded an ASCII character followed by
648            a non-ASCII character. (The code for advancing by one character rather
649            than one byte was nonsense.)
650    
651        (c) The pcredemo.c sample program did not have any code at all to handle
652            the cases when CRLF is a valid newline sequence.
653    
654    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
655        as a starting offset was within the subject string. There is now a new
656        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
657        negative or greater than the length of the string. In order to test this,
658        pcretest is extended to allow the setting of negative starting offsets.
659    
660    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
661        starting offset points to the beginning of a UTF-8 character was
662        unnecessarily clumsy. I tidied it up.
663    
664    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
665        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
666    
667    17. Nobody had reported that the --include_dir option, which was added in
668        release 7.7 should have been called --include-dir (hyphen, not underscore)
669        for compatibility with GNU grep. I have changed it to --include-dir, but
670        left --include_dir as an undocumented synonym, and the same for
671        --exclude-dir, though that is not available in GNU grep, at least as of
672        release 2.5.4.
673    
674    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
675        characters from a string of bytes) have been redefined so as not to use
676        loops, in order to improve performance in some environments. At the same
677        time, I abstracted some of the common code into auxiliary macros to save
678        repetition (this should not affect the compiled code).
679    
680    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
681        compile-time error is now given if \c is not followed by an ASCII
682        character, that is, a byte less than 128. (In EBCDIC mode, the code is
683        different, and any byte value is allowed.)
684    
685    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
686        START_OPTIMIZE option, which is now allowed at compile time - but just
687        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
688        to pcregrep and other applications that have no direct access to PCRE
689        options. The new /Y option in pcretest sets this option when calling
690        pcre_compile().
691    
692    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
693        back references. Groups containing recursive back references were forced to
694        be atomic by that change, but in the case of named groups, the amount of
695        memory required was incorrectly computed, leading to "Failed: internal
696        error: code overflow". This has been fixed.
697    
698    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
699        pcretest.c, to avoid build problems in some Borland environments.
700    
701    
702    Version 8.10 25-Jun-2010
703    ------------------------
704    
705    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
706        THEN.
707    
708    2.  (*ACCEPT) was not working when inside an atomic group.
709    
710    3.  Inside a character class, \B is treated as a literal by default, but
711        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
712        causes the error). The code is unchanged, but I tidied the documentation.
713    
714    4.  Inside a character class, PCRE always treated \R and \X as literals,
715        whereas Perl faults them if its -w option is set. I have changed PCRE so
716        that it faults them when PCRE_EXTRA is set.
717    
718    5.  Added support for \N, which always matches any character other than
719        newline. (It is the same as "." when PCRE_DOTALL is not set.)
720    
721    6.  When compiling pcregrep with newer versions of gcc which may have
722        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
723        declared with attribute warn_unused_result" were given. Just casting the
724        result to (void) does not stop the warnings; a more elaborate fudge is
725        needed. I've used a macro to implement this.
726    
727    7.  Minor change to pcretest.c to avoid a compiler warning.
728    
729    8.  Added four artifical Unicode properties to help with an option to make
730        \s etc use properties (see next item). The new properties are: Xan
731        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
732    
733    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
734        use Unicode properties. (*UCP) at the start of a pattern can be used to set
735        this option. Modified pcretest to add /W to test this facility. Added
736        REG_UCP to make it available via the POSIX interface.
737    
738    10. Added --line-buffered to pcregrep.
739    
740    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
741        studied, and the match started with a letter with a code point greater than
742        127 whose first byte was different to the first byte of the other case of
743        the letter, the other case of this starting letter was not recognized
744        (#976).
745    
746    12. If a pattern that was studied started with a repeated Unicode property
747        test, for example, \p{Nd}+, there was the theoretical possibility of
748        setting up an incorrect bitmap of starting bytes, but fortunately it could
749        not have actually happened in practice until change 8 above was made (it
750        added property types that matched character-matching opcodes).
751    
752    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
753        possible starting bytes for non-anchored patterns.
754    
755    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
756        \R, and also a number of cases that involve Unicode properties, both
757        explicit and implicit when PCRE_UCP is set.
758    
759    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
760        input, it could crash or give wrong results if characters with values
761        greater than 0xc0 were present in the subject string. (Detail: it assumed
762        UTF-8 input when processing these items.)
763    
764    16. Added a lot of (int) casts to avoid compiler warnings in systems where
765        size_t is 64-bit (#991).
766    
767    17. Added a check for running out of memory when PCRE is compiled with
768        --disable-stack-for-recursion (#990).
769    
770    18. If the last data line in a file for pcretest does not have a newline on
771        the end, a newline was missing in the output.
772    
773    19. The default pcre_chartables.c file recognizes only ASCII characters (values
774        less than 128) in its various bitmaps. However, there is a facility for
775        generating tables according to the current locale when PCRE is compiled. It
776        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
777        characters, are recognized by isspace() and therefore were getting set in
778        these tables, and indeed these tables seem to approximate to ISO 8859. This
779        caused a problem in UTF-8 mode when pcre_study() was used to create a list
780        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
781        which of course cannot start UTF-8 characters. I have changed the code so
782        that only real ASCII characters (less than 128) and the correct starting
783        bytes for UTF-8 encodings are set for characters greater than 127 when in
784        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
785        altogether.)
786    
787    20. Added the /T option to pcretest so as to be able to run tests with non-
788        standard character tables, thus making it possible to include the tests
789        used for 19 above in the standard set of tests.
790    
791    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
792        reference to a subpattern the other side of a comment that contains an
793        opening parenthesis caused either an internal compiling error, or a
794        reference to the wrong subpattern.
795    
796    
797    Version 8.02 19-Mar-2010
798    ------------------------
799    
800    1.  The Unicode data tables have been updated to Unicode 5.2.0.
801    
802    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
803        configured.
804    
805    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
806        original author of that file, following a query about its status.
807    
808    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
809        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
810    
811    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
812        quantifier applied to a forward-referencing subroutine call, could compile
813        incorrect code or give the error "internal error: previously-checked
814        referenced subpattern not found".
815    
816    6.  Both MS Visual Studio and Symbian OS have problems with initializing
817        variables to point to external functions. For these systems, therefore,
818        pcre_malloc etc. are now initialized to local functions that call the
819        relevant global functions.
820    
821    7.  There were two entries missing in the vectors called coptable and poptable
822        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
823        I've fixed the data, and added a kludgy way of testing at compile time that
824        the lengths are correct (equal to the number of opcodes).
825    
826    8.  Following on from 7, I added a similar kludge to check the length of the
827        eint vector in pcreposix.c.
828    
829    9.  Error texts for pcre_compile() are held as one long string to avoid too
830        much relocation at load time. To find a text, the string is searched,
831        counting zeros. There was no check for running off the end of the string,
832        which could happen if a new error number was added without updating the
833        string.
834    
835    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
836    
837    11. \K was not working if it appeared in an atomic group or in a group that
838        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
839        \K is "not well defined" if used in an assertion. PCRE now accepts it if
840        the assertion is positive, but not if it is negative.
841    
842    12. Change 11 fortuitously reduced the size of the stack frame used in the
843        "match()" function of pcre_exec.c by one pointer. Forthcoming
844        implementation of support for (*MARK) will need an extra pointer on the
845        stack; I have reserved it now, so that the stack frame size does not
846        decrease.
847    
848    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
849        item in branch that calls a recursion is a subroutine call - as in the
850        second branch in the above example - was incorrectly given the compile-
851        time error "recursive call could loop indefinitely" because pcre_compile()
852        was not correctly checking the subroutine for matching a non-empty string.
853    
854    14. The checks for overrunning compiling workspace could trigger after an
855        overrun had occurred. This is a "should never occur" error, but it can be
856        triggered by pathological patterns such as hundreds of nested parentheses.
857        The checks now trigger 100 bytes before the end of the workspace.
858    
859    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
860    
861    
862    Version 8.01 19-Jan-2010
863    ------------------------
864    
865    1.  If a pattern contained a conditional subpattern with only one branch (in
866        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
867        computed the wrong minimum data length (which is of course zero for such
868        subpatterns). This could cause incorrect "no match" results.
869    
870    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
871        the pattern is reset in the first branch, pcre_compile() failed with
872        "internal error: code overflow at offset...". This happened only when
873        the reset was to the original external option setting. (An optimization
874        abstracts leading options settings into an external setting, which was the
875        cause of this.)
876    
877    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
878        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
879        assertion pattern did not match (meaning that the assertion was true), it
880        was incorrectly treated as false if the SKIP had been reached during the
881        matching. This also applied to assertions used as conditions.
882    
883    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
884        assertion subpattern, including such a pattern used as a condition,
885        unpredictable results occurred, instead of the error return
886        PCRE_ERROR_DFA_UITEM.
887    
888    5.  The C++ GlobalReplace function was not working like Perl for the special
889        situation when an empty string is matched. It now does the fancy magic
890        stuff that is necessary.
891    
892    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
893        removed. (These were left over from very, very early versions of PCRE.)
894    
895    7.  Some cosmetic changes to the code to make life easier when compiling it
896        as part of something else:
897    
898        (a) Change DEBUG to PCRE_DEBUG.
899    
900        (b) In pcre_compile(), rename the member of the "branch_chain" structure
901            called "current" as "current_branch", to prevent a collision with the
902            Linux macro when compiled as a kernel module.
903    
904        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
905            prevent a collision with the Linux macro when compiled as a kernel
906            module.
907    
908    8.  In pcre_compile() there are some checks for integer overflows that used to
909        cast potentially large values to (double). This has been changed to that
910        when building, a check for int64_t is made, and if it is found, it is used
911        instead, thus avoiding the use of floating point arithmetic. (There is no
912        other use of FP in PCRE.) If int64_t is not found, the fallback is to
913        double.
914    
915    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
916        2005 (difference between two addresses compared to an unsigned value).
917    
918    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
919        custom one, because of the following reported problem in Windows:
920    
921          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
922              under Win32.
923          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
924              therefore missing the function definition.
925          - The compiler thus generates a "C" signature for the test function.
926          - The linker fails to find the "C" function.
927          - PCRE fails to configure if asked to do so against libbz2.
928    
929    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
930        messages were output:
931    
932          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
933          rerunning libtoolize, to keep the correct libtool macros in-tree.
934          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
935    
936        I have done both of these things.
937    
938    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
939        most of the time, it *can* run out if it is given a pattern that contains a
940        runaway infinite recursion. I updated the discussion in the pcrestack man
941        page.
942    
943    13. Now that we have gone to the x.xx style of version numbers, the minor
944        version may start with zero. Using 08 or 09 is a bad idea because users
945        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
946        interpreted as invalid octal numbers. I've updated the previous comment in
947        configure.ac, and also added a check that gives an error if 08 or 09 are
948        used.
949    
950    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
951        causing partial matching to fail when the end of the subject matched \W
952        in a UTF-8 pattern where \W was quantified with a minimum of 3.
953    
954    15. There were some discrepancies between the declarations in pcre_internal.h
955        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
956        their definitions. The declarations used "const uschar *" and the
957        definitions used USPTR. Even though USPTR is normally defined as "const
958        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
959        reported that: "This difference in casting confuses some C++ compilers, for
960        example, SunCC recognizes above declarations as different functions and
961        generates broken code for hbpcre." I have changed the declarations to use
962        USPTR.
963    
964    16. GNU libtool is named differently on some systems. The autogen.sh script now
965        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
966        (FreeBSD).
967    
968    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
969        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
970        comment: "Figure out how to create a longlong from a string: strtoll and
971        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
972        instance, but it only takes 2 args instead of 3!"
973    
974    18. A subtle bug concerned with back references has been fixed by a change of
975        specification, with a corresponding code fix. A pattern such as
976        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
977        refers, was giving matches when it shouldn't. For example, xa=xaaa would
978        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
979        same bug. Such groups have to be quantified to be useful, or contained
980        inside another quantified group. (If there's no repetition, the reference
981        can never match.) The problem arises because, having left the group and
982        moved on to the rest of the pattern, a later failure that backtracks into
983        the group uses the captured value from the final iteration of the group
984        rather than the correct earlier one. I have fixed this in PCRE by forcing
985        any group that contains a reference to itself to be an atomic group; that
986        is, there cannot be any backtracking into it once it has completed. This is
987        similar to recursive and subroutine calls.
988    
989    
990    Version 8.00 19-Oct-09
991    ----------------------
992    
993    1.  The table for translating pcre_compile() error codes into POSIX error codes
994        was out-of-date, and there was no check on the pcre_compile() error code
995        being within the table. This could lead to an OK return being given in
996        error.
997    
998    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
999        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1000        in a Windows environment.
1001    
1002    3.  The pcregrep --count option prints the count for each file even when it is
1003        zero, as does GNU grep. However, pcregrep was also printing all files when
1004        --files-with-matches was added. Now, when both options are given, it prints
1005        counts only for those files that have at least one match. (GNU grep just
1006        prints the file name in this circumstance, but including the count seems
1007        more useful - otherwise, why use --count?) Also ensured that the
1008        combination -clh just lists non-zero counts, with no names.
1009    
1010    4.  The long form of the pcregrep -F option was incorrectly implemented as
1011        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1012        but it seems right to fix it, and I didn't think it was worth preserving
1013        the old behaviour.
1014    
1015    5.  The command line items --regex=pattern and --regexp=pattern were not
1016        recognized by pcregrep, which required --regex pattern or --regexp pattern
1017        (with a space rather than an '='). The man page documented the '=' forms,
1018        which are compatible with GNU grep; these now work.
1019    
1020    6.  No libpcreposix.pc file was created for pkg-config; there was just
1021        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1022    
1023    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1024        when UCP support is not needed, by modifying the Python script that
1025        generates it from Unicode data files. This should not matter if the module
1026        is correctly used as a library, but I received one complaint about 50K of
1027        unwanted data. My guess is that the person linked everything into his
1028        program rather than using a library. Anyway, it does no harm.
1029    
1030    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1031        was a minimum greater than 1 for a wide character in a possessive
1032        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1033        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1034        character. Chaos in the form of incorrect output or a compiling loop could
1035        result.
1036    
1037    9.  The restrictions on what a pattern can contain when partial matching is
1038        requested for pcre_exec() have been removed. All patterns can now be
1039        partially matched by this function. In addition, if there are at least two
1040        slots in the offset vector, the offset of the earliest inspected character
1041        for the match and the offset of the end of the subject are set in them when
1042        PCRE_ERROR_PARTIAL is returned.
1043    
1044    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1045        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1046        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1047        and may be more useful for multi-segment matching.
1048    
1049    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1050        used to be given if ever the end of the subject was reached; now it is
1051        given only if matching could not proceed because another character was
1052        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1053        string "Z", which now yields "no match" instead of "partial match". In the
1054        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1055        final character ended with (*FAIL).
1056    
1057    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1058        if the pattern had a "must contain" character that was already found in the
1059        earlier partial match, unless partial matching was again requested. For
1060        example, with the pattern /dog.(body)?/, the "must contain" character is
1061        "g". If the first part-match was for the string "dog", restarting with
1062        "sbody" failed. This bug has been fixed.
1063    
1064    13. The string returned by pcre_dfa_exec() after a partial match has been
1065        changed so that it starts at the first inspected character rather than the
1066        first character of the match. This makes a difference only if the pattern
1067        starts with a lookbehind assertion or \b or \B (\K is not supported by
1068        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1069        matching functions compatible, and I think it's the right thing to do.
1070    
1071    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1072        so that the demonstration program is easily available in environments where
1073        PCRE has not been installed from source.
1074    
1075    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1076        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1077        library.
1078    
1079    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1080        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1081        is not the first non-POSIX option to be added. Clearly some people find
1082        these options useful.
1083    
1084    17. If a caller to the POSIX matching function regexec() passes a non-zero
1085        value for nmatch with a NULL value for pmatch, the value of
1086        nmatch is forced to zero.
1087    
1088    18. RunGrepTest did not have a test for the availability of the -u option of
1089        the diff command, as RunTest does. It now checks in the same way as
1090        RunTest, and also checks for the -b option.
1091    
1092    19. If an odd number of negated classes containing just a single character
1093        interposed, within parentheses, between a forward reference to a named
1094        subpattern and the definition of the subpattern, compilation crashed with
1095        an internal error, complaining that it could not find the referenced
1096        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1097        [The bug was that it was starting one character too far in when skipping
1098        over the character class, thus treating the ] as data rather than
1099        terminating the class. This meant it could skip too much.]
1100    
1101    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1102        /g option in pcretest when the pattern contains \K, which makes it possible
1103        to have an empty string match not at the start, even when the pattern is
1104        anchored. Updated pcretest and pcredemo to use this option.
1105    
1106    21. If the maximum number of capturing subpatterns in a recursion was greater
1107        than the maximum at the outer level, the higher number was returned, but
1108        with unset values at the outer level. The correct (outer level) value is
1109        now given.
1110    
1111    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1112        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1113        make it do so. The string so far is captured, making this feature
1114        compatible with Perl.
1115    
1116    23. The tests have been re-organized, adding tests 11 and 12, to make it
1117        possible to check the Perl 5.10 features against Perl 5.10.
1118    
1119    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1120        pattern matches a fixed length string. PCRE did not allow this; now it
1121        does. Neither allows recursion.
1122    
1123    25. I finally figured out how to implement a request to provide the minimum
1124        length of subject string that was needed in order to match a given pattern.
1125        (It was back references and recursion that I had previously got hung up
1126        on.) This code has now been added to pcre_study(); it finds a lower bound
1127        to the length of subject needed. It is not necessarily the greatest lower
1128        bound, but using it to avoid searching strings that are too short does give
1129        some useful speed-ups. The value is available to calling programs via
1130        pcre_fullinfo().
1131    
1132    26. While implementing 25, I discovered to my embarrassment that pcretest had
1133        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1134        study optimizations had never been tested with that matching function.
1135        Oops. What is worse, even when it was passed study data, there was a bug in
1136        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1137        were also very few tests of studied patterns with pcre_dfa_exec().
1138    
1139    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1140        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1141        on the other side of the coin, they are no longer allowed to have different
1142        names, because these cannot be distinguished in PCRE, and this has caused
1143        confusion. (This is a difference from Perl.)
1144    
1145    28. When duplicate subpattern names are present (necessarily with different
1146        numbers, as required by 27 above), and a test is made by name in a
1147        conditional pattern, either for a subpattern having been matched, or for
1148        recursion in such a pattern, all the associated numbered subpatterns are
1149        tested, and the overall condition is true if the condition is true for any
1150        one of them. This is the way Perl works, and is also more like the way
1151        testing by number works.
1152    
1153    
1154    Version 7.9 11-Apr-09
1155  ---------------------  ---------------------
1156    
1157  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 17  Version 7.9 xx-xxx-09 Line 1167  Version 7.9 xx-xxx-09
1167      but BOOL is not.      but BOOL is not.
1168    
1169  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1170      PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.      PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1171    
1172  4.  The pcregrep documentation said spaces were inserted as well as colons (or  4.  The pcregrep documentation said spaces were inserted as well as colons (or
1173      hyphens) following file names and line numbers when outputting matching      hyphens) following file names and line numbers when outputting matching
# Line 42  Version 7.9 xx-xxx-09 Line 1192  Version 7.9 xx-xxx-09
1192      correctly handled. The rule now is that both the assertion and what follows      correctly handled. The rule now is that both the assertion and what follows
1193      in the first alternative must satisfy the test.      in the first alternative must satisfy the test.
1194    
1195  9.  If auto-callout was enabled in a pattern with a conditional group whose  9.  If auto-callout was enabled in a pattern with a conditional group whose
1196      condition was an assertion, PCRE could crash during matching, both with      condition was an assertion, PCRE could crash during matching, both with
1197      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
1198    
# Line 64  Version 7.9 xx-xxx-09 Line 1214  Version 7.9 xx-xxx-09
1214  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1215      from Martin Jerabek that uses macro names for all relevant character and      from Martin Jerabek that uses macro names for all relevant character and
1216      string constants.      string constants.
1217    
1218  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1219      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1220      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1221      these, but not everybody uses configure.      these, but not everybody uses configure.
1222    
1223  19. A conditional group that had only one branch was not being correctly  19. A conditional group that had only one branch was not being correctly
1224      recognized as an item that could match an empty string. This meant that an      recognized as an item that could match an empty string. This meant that an
1225      enclosing group might also not be so recognized, causing infinite looping      enclosing group might also not be so recognized, causing infinite looping
1226      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1227      with the subject "ab", where knowledge that the repeated group can match      with the subject "ab", where knowledge that the repeated group can match
1228      nothing is needed in order to break the loop.      nothing is needed in order to break the loop.
1229    
1230  20. If a pattern that was compiled with callouts was matched using pcre_dfa_  20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1231      exec(), but without supplying a callout function, matching went wrong.      exec(), but without supplying a callout function, matching went wrong.
1232    
1233  21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory  21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1234      leak if the size of the offset vector was greater than 30. When the vector      leak if the size of the offset vector was greater than 30. When the vector
1235      is smaller, the saved offsets during recursion go onto a local stack      is smaller, the saved offsets during recursion go onto a local stack
1236      vector, but for larger vectors malloc() is used. It was failing to free      vector, but for larger vectors malloc() is used. It was failing to free
1237      when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"      when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1238      error, in fact).      error, in fact).
1239    
1240  22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the  22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1241      heapframe that is used only when UTF-8 support is enabled. This caused no      heapframe that is used only when UTF-8 support is enabled. This caused no
1242      problem, but was untidy.      problem, but was untidy.
1243    
1244    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1245        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1246        included within another project.
1247    
1248    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1249        slightly modified by me:
1250    
1251          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1252              not building pcregrep.
1253    
1254          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1255              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1256    
1257    25. Forward references, both numeric and by name, in patterns that made use of
1258        duplicate group numbers, could behave incorrectly or give incorrect errors,
1259        because when scanning forward to find the reference group, PCRE was not
1260        taking into account the duplicate group numbers. A pattern such as
1261        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1262    
1263    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1264        the feature of a custom pointer more persuasive (as requested by a user).
1265    
1266    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1267        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1268        pre-defined.
1269    
1270    28. Added support for (*UTF8) at the start of a pattern.
1271    
1272    29. Arrange for flags added by the "release type" setting in CMake to be shown
1273        in the configuration summary.
1274    
1275    
1276  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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