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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.3 05-Jul-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    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
38    
39    10. Get rid of a number of -Wunused-but-set-variable warnings.
40    
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses. It also applied to some
46        assertions.
47    
48    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49        information out of configure.ac instead of relying on pcre.h.generic, which
50        is not stored in the repository.
51    
52    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53        -lreadline.
54    
55    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
56    
57    15. Applied Graycode's patch to put the top-level frame on the stack rather
58        than the heap when not using the stack for recursion. This gives a
59        performance improvement in many cases when recursion is not deep.
60    
61    16. Experimental code added to "pcretest -C" to output the stack frame size.
62    
63    
64    Version 8.21 12-Dec-2011
65    ------------------------
66    
67    1.  Updating the JIT compiler.
68    
69    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
70        are added as well.
71    
72    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
73        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
74        calling _pcre_jit_exec. Some extra comments are added.
75    
76    4.  (*MARK) settings inside atomic groups that do not contain any capturing
77        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
78        was introduced by change 18 for 8.20.
79    
80    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
81        ECMA-262 standard.
82    
83    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
84        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
85        This bug was probably introduced by change 9 of 8.13.
86    
87    7.  While fixing 6 above, I noticed that a number of other items were being
88        incorrectly rejected as "not fixed length". This arose partly because newer
89        opcodes had not been added to the fixed-length checking code. I have (a)
90        corrected the bug and added tests for these items, and (b) arranged for an
91        error to occur if an unknown opcode is encountered while checking for fixed
92        length instead of just assuming "not fixed length". The items that were
93        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
94        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
95        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
96    
97    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
98        being incorrectly compiled and would have given unpredicatble results.
99    
100    9.  A possessively repeated subpattern with minimum repeat count greater than
101        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
102        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
103        the first (A) could occur when it should not.
104    
105    10. Add a cast and remove a redundant test from the code.
106    
107    11. JIT should use pcre_malloc/pcre_free for allocation.
108    
109    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
110        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
111        is anything other than /usr, -L is still shown).
112    
113    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
114    
115    14. Perl does not support \N without a following name in a [] class; PCRE now
116        also gives an error.
117    
118    15. If a forward reference was repeated with an upper limit of around 2000,
119        it caused the error "internal error: overran compiling workspace". The
120        maximum number of forward references (including repeats) was limited by the
121        internal workspace, and dependent on the LINK_SIZE. The code has been
122        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
123        the default depends on LINK_SIZE. There is a new upper limit (for safety)
124        of around 200,000 forward references. While doing this, I also speeded up
125        the filling in of repeated forward references.
126    
127    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
128        incorrectly expecting the subject to contain another "a" after the start.
129    
130    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
131        in the match, the SKIP should be ignored. This was not happening; instead
132        the SKIP was being treated as NOMATCH. For patterns such as
133        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
134        tested.
135    
136    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
137        now much more compatible with Perl, in particular in cases where the result
138        is a non-match for a non-anchored pattern. For example, if
139        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
140        "m", where previously it did not return a name. A side effect of this
141        change is that for partial matches, the last encountered mark name is
142        returned, as for non matches. A number of tests that were previously not
143        Perl-compatible have been moved into the Perl-compatible test files. The
144        refactoring has had the pleasing side effect of removing one argument from
145        the match() function, thus reducing its stack requirements.
146    
147    19. If the /S+ option was used in pcretest to study a pattern using JIT,
148        subsequent uses of /S (without +) incorrectly behaved like /S+.
149    
150    21. Retrieve executable code size support for the JIT compiler and fixing
151        some warnings.
152    
153    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
154        not work when the shorter character appeared right at the end of the
155        subject string.
156    
157    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
158        systems.
159    
160    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
161        output it when the /M option is used in pcretest.
162    
163    25. The CheckMan script was not being included in the distribution. Also, added
164        an explicit "perl" to run Perl scripts from the PrepareRelease script
165        because this is reportedly needed in Windows.
166    
167    26. If study data was being save in a file and studying had not found a set of
168        "starts with" bytes for the pattern, the data written to the file (though
169        never used) was taken from uninitialized memory and so caused valgrind to
170        complain.
171    
172    27. Updated RunTest.bat as provided by Sheri Pierce.
173    
174    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
175    
176    29. Computation of memory usage for the table of capturing group names was
177        giving an unnecessarily large value.
178    
179    
180    Version 8.20 21-Oct-2011
181    ------------------------
182    
183    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
184        a POSIX class. After further experiments with Perl, which convinced me that
185        Perl has bugs and confusions, a closing square bracket is no longer allowed
186        in a POSIX name. This bug also affected patterns with classes that started
187        with full stops.
188    
189    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
190        captured substring, but while checking the failing first alternative,
191        substring 1 is temporarily captured. If the output vector supplied to
192        pcre_exec() was not big enough for this capture, the yield of the function
193        was still zero ("insufficient space for captured substrings"). This cannot
194        be totally fixed without adding another stack variable, which seems a lot
195        of expense for a edge case. However, I have improved the situation in cases
196        such as /(a)(b)x|abc/ matched against "abc", where the return code
197        indicates that fewer than the maximum number of slots in the ovector have
198        been set.
199    
200    3.  Related to (2) above: when there are more back references in a pattern than
201        slots in the output vector, pcre_exec() uses temporary memory during
202        matching, and copies in the captures as far as possible afterwards. It was
203        using the entire output vector, but this conflicts with the specification
204        that only 2/3 is used for passing back captured substrings. Now it uses
205        only the first 2/3, for compatibility. This is, of course, another edge
206        case.
207    
208    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
209        main code base, and can be used by building with --enable-jit. When this is
210        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
211        runtime --no-jit option is given.
212    
213    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
214        ovector, the return from the function was zero, implying that there were
215        other matches that did not fit. The correct "exactly full" value is now
216        returned.
217    
218    6.  If a subpattern that was called recursively or as a subroutine contained
219        (*PRUNE) or any other control that caused it to give a non-standard return,
220        invalid errors such as "Error -26 (nested recursion at the same subject
221        position)" or even infinite loops could occur.
222    
223    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
224        computing the minimum length on reaching *ACCEPT, and so ended up with the
225        wrong value of 1 rather than 0. Further investigation indicates that
226        computing a minimum subject length in the presence of *ACCEPT is difficult
227        (think back references, subroutine calls), and so I have changed the code
228        so that no minimum is registered for a pattern that contains *ACCEPT.
229    
230    8.  If (*THEN) was present in the first (true) branch of a conditional group,
231        it was not handled as intended. [But see 16 below.]
232    
233    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
234        Sheri Pierce.
235    
236    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
237        the first byte in a match must be "a".
238    
239    11. Change 17 for 8.13 increased the recursion depth for patterns like
240        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
241        pattern contains any instances of (*THEN). If it does not, the old
242        optimizations are restored. It would be nice to do this on a per-group
243        basis, but at the moment that is not feasible.
244    
245    12. In some environments, the output of pcretest -C is CRLF terminated. This
246        broke RunTest's code that checks for the link size. A single white space
247        character after the value is now allowed for.
248    
249    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
250        For "fr", it uses the Windows-specific input and output files.
251    
252    14. If (*THEN) appeared in a group that was called recursively or as a
253        subroutine, it did not work as intended. [But see next item.]
254    
255    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
256        pattern fragments (but not containing any | characters). If A and B are
257        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
258        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
259        D. In other words, Perl considers parentheses that do not contain any |
260        characters to be part of a surrounding alternative, whereas PCRE was
261        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
262        differently. PCRE now behaves in the same way as Perl, except in the case
263        of subroutine/recursion calls such as (?1) which have in any case always
264        been different (but PCRE had them first :-).
265    
266    16. Related to 15 above: Perl does not treat the | in a conditional group as
267        creating alternatives. Such a group is treated in the same way as an
268        ordinary group without any | characters when processing (*THEN). PCRE has
269        been changed to match Perl's behaviour.
270    
271    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
272        RunGrepTest script failed.
273    
274    18. Change 22 for version 13 caused atomic groups to use more stack. This is
275        inevitable for groups that contain captures, but it can lead to a lot of
276        stack use in large patterns. The old behaviour has been restored for atomic
277        groups that do not contain any capturing parentheses.
278    
279    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
280        suppress the check for a minimum subject length at run time. (If it was
281        given to pcre_exec() or pcre_dfa_exec() it did work.)
282    
283    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
284        fail to work when decoding hex characters in data strings in EBCDIC
285        environments.
286    
287    21. It appears that in at least one Mac OS environment, the isxdigit() function
288        is implemented as a macro that evaluates to its argument more than once,
289        contravening the C 90 Standard (I haven't checked a later standard). There
290        was an instance in pcretest which caused it to go wrong when processing
291        \x{...} escapes in subject strings. The has been rewritten to avoid using
292        things like p++ in the argument of isxdigit().
293    
294    
295    Version 8.13 16-Aug-2011
296    ------------------------
297    
298    1.  The Unicode data tables have been updated to Unicode 6.0.0.
299    
300    2.  Two minor typos in pcre_internal.h have been fixed.
301    
302    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
303        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
304        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
305    
306    4.  There were a number of related bugs in the code for matching backrefences
307        caselessly in UTF-8 mode when codes for the characters concerned were
308        different numbers of bytes. For example, U+023A and U+2C65 are an upper
309        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
310        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
311        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
312        2-byte code at the end of the subject (it thought there wasn't enough data
313        left).
314    
315    5.  Comprehensive information about what went wrong is now returned by
316        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
317        as the output vector has at least 2 elements. The offset of the start of
318        the failing character and a reason code are placed in the vector.
319    
320    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
321        now returned is for the first byte of the failing character, instead of the
322        last byte inspected. This is an incompatible change, but I hope it is small
323        enough not to be a problem. It makes the returned offset consistent with
324        pcre_exec() and pcre_dfa_exec().
325    
326    7.  pcretest now gives a text phrase as well as the error number when
327        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
328        failure, the offset and reason code are output.
329    
330    8.  When \R was used with a maximizing quantifier it failed to skip backwards
331        over a \r\n pair if the subsequent match failed. Instead, it just skipped
332        back over a single character (\n). This seems wrong (because it treated the
333        two characters as a single entity when going forwards), conflicts with the
334        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
335        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
336        has been changed.
337    
338    9.  Some internal refactoring has changed the processing so that the handling
339        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
340        time (the PCRE_DOTALL option was changed this way some time ago: version
341        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
342        which was always a bit of a fudge. It also means that there is one less
343        argument for the match() function, which reduces its stack requirements
344        slightly. This change also fixes an incompatibility with Perl: the pattern
345        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
346    
347    10. More internal refactoring has drastically reduced the number of recursive
348        calls to match() for possessively repeated groups such as (abc)++ when
349        using pcre_exec().
350    
351    11. While implementing 10, a number of bugs in the handling of groups were
352        discovered and fixed:
353    
354        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
355        (a|)*(?1) gave a compile-time internal error.
356        ((a|)+)+  did not notice that the outer group could match an empty string.
357        (^a|^)+   was not marked as anchored.
358        (.*a|.*)+ was not marked as matching at start or after a newline.
359    
360    12. Yet more internal refactoring has removed another argument from the match()
361        function. Special calls to this function are now indicated by setting a
362        value in a variable in the "match data" data block.
363    
364    13. Be more explicit in pcre_study() instead of relying on "default" for
365        opcodes that mean there is no starting character; this means that when new
366        ones are added and accidentally left out of pcre_study(), testing should
367        pick them up.
368    
369    14. The -s option of pcretest has been documented for ages as being an old
370        synonym of -m (show memory usage). I have changed it to mean "force study
371        for every regex", that is, assume /S for every regex. This is similar to -i
372        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
373        using it. It makes it easier to run collections of tests with and without
374        study enabled, and thereby test pcre_study() more easily. All the standard
375        tests are now run with and without -s (but some patterns can be marked as
376        "never study" - see 20 below).
377    
378    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
379        restoration of the capturing data to the outer values was not happening
380        correctly.
381    
382    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
383        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
384        pattern had matched an empty string, and so incorrectly returned a no
385        match.
386    
387    17. There was optimizing code for the last branch of non-capturing parentheses,
388        and also for the obeyed branch of a conditional subexpression, which used
389        tail recursion to cut down on stack usage. Unfortunately, now that there is
390        the possibility of (*THEN) occurring in these branches, tail recursion is
391        no longer possible because the return has to be checked for (*THEN). These
392        two optimizations have therefore been removed. [But see 8.20/11 above.]
393    
394    18. If a pattern containing \R was studied, it was assumed that \R always
395        matched two bytes, thus causing the minimum subject length to be
396        incorrectly computed because \R can also match just one byte.
397    
398    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
399        was incorrectly computed.
400    
401    20. If /S is present twice on a test pattern in pcretest input, it now
402        *disables* studying, thereby overriding the use of -s on the command line
403        (see 14 above). This is necessary for one or two tests to keep the output
404        identical in both cases.
405    
406    21. When (*ACCEPT) was used in an assertion that matched an empty string and
407        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
408    
409    22. When an atomic group that contained a capturing parenthesis was
410        successfully matched, but the branch in which it appeared failed, the
411        capturing was not being forgotten if a higher numbered group was later
412        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
413        group 1 to "a", when in fact it should be unset. This applied to multi-
414        branched capturing and non-capturing groups, repeated or not, and also to
415        positive assertions (capturing in negative assertions does not happen
416        in PCRE) and also to nested atomic groups.
417    
418    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
419        subject after a captured substring, to make it easier to tell which of a
420        number of identical substrings has been captured.
421    
422    24. The way atomic groups are processed by pcre_exec() has been changed so that
423        if they are repeated, backtracking one repetition now resets captured
424        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
425        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
426        "aaa". Previously, it would have been "a". As part of this code
427        refactoring, the way recursive calls are handled has also been changed.
428    
429    25. If an assertion condition captured any substrings, they were not passed
430        back unless some other capturing happened later. For example, if
431        (?(?=(a))a) was matched against "a", no capturing was returned.
432    
433    26. When studying a pattern that contained subroutine calls or assertions,
434        the code for finding the minimum length of a possible match was handling
435        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
436        group 1 called group 2 while simultaneously a separate group 2 called group
437        1). A stack overflow occurred in this case. I have fixed this by limiting
438        the recursion depth to 10.
439    
440    27. Updated RunTest.bat in the distribution to the version supplied by Tom
441        Fortmann. This supports explicit test numbers on the command line, and has
442        argument validation and error reporting.
443    
444    28. An instance of \X with an unlimited repeat could fail if at any point the
445        first character it looked at was a mark character.
446    
447    29. Some minor code refactoring concerning Unicode properties and scripts
448        should reduce the stack requirement of match() slightly.
449    
450    30. Added the '=' option to pcretest to check the setting of unused capturing
451        slots at the end of the pattern, which are documented as being -1, but are
452        not included in the return count.
453    
454    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
455        compiled something random. Now it gives a compile-time error (as does
456        Perl).
457    
458    32. A *MARK encountered during the processing of a positive assertion is now
459        recorded and passed back (compatible with Perl).
460    
461    33. If --only-matching or --colour was set on a pcregrep call whose pattern
462        had alternative anchored branches, the search for a second match in a line
463        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
464        matched the line "0102" twice. The same bug affected patterns that started
465        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
466        twice.
467    
468    34. Previously, PCRE did not allow quantification of assertions. However, Perl
469        does, and because of capturing effects, quantifying parenthesized
470        assertions may at times be useful. Quantifiers are now allowed for
471        parenthesized assertions.
472    
473    35. A minor code tidy in pcre_compile() when checking options for \R usage.
474    
475    36. \g was being checked for fancy things in a character class, when it should
476        just be a literal "g".
477    
478    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
479        appearance of a nested POSIX class supersedes an apparent external class.
480        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
481        unescaped square brackets may also appear as part of class names. For
482        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
483        more like Perl. (But see 8.20/1 above.)
484    
485    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
486        was because it thought it was \N{name}, which is not supported).
487    
488    39. Add minix to OS list not supporting the -S option in pcretest.
489    
490    40. PCRE tries to detect cases of infinite recursion at compile time, but it
491        cannot analyze patterns in sufficient detail to catch mutual recursions
492        such as ((?1))((?2)). There is now a runtime test that gives an error if a
493        subgroup is called recursively as a subpattern for a second time at the
494        same position in the subject string. In previous releases this might have
495        been caught by the recursion limit, or it might have run out of stack.
496    
497    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
498        happen only once. PCRE was, however incorrectly giving a compile time error
499        "recursive call could loop indefinitely" because it cannot analyze the
500        pattern in sufficient detail. The compile time test no longer happens when
501        PCRE is compiling a conditional subpattern, but actual runaway loops are
502        now caught at runtime (see 40 above).
503    
504    42. It seems that Perl allows any characters other than a closing parenthesis
505        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
506        has been changed to be the same.
507    
508    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
509        as not to get warnings when autogen.sh is called. Also changed
510        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
511    
512    44. To help people who use pcregrep to scan files containing exceedingly long
513        lines, the following changes have been made:
514    
515        (a) The default value of the buffer size parameter has been increased from
516            8K to 20K. (The actual buffer used is three times this size.)
517    
518        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
519            PCRE is built.
520    
521        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
522            to be set at run time.
523    
524        (d) Numerical values in pcregrep options can be followed by K or M, for
525            example --buffer-size=50K.
526    
527        (e) If a line being scanned overflows pcregrep's buffer, an error is now
528            given and the return code is set to 2.
529    
530    45. Add a pointer to the latest mark to the callout data block.
531    
532    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
533        partial match of an empty string instead of no match. This was specific to
534        the use of ".".
535    
536    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
537        complete match instead of a partial match. This bug was dependent on both
538        the PCRE_UTF8 and PCRE_DOTALL options being set.
539    
540    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
541        starting byte set, because \b was not being ignored.
542    
543    
544    Version 8.12 15-Jan-2011
545    ------------------------
546    
547    1.  Fixed some typos in the markup of the man pages, and wrote a script that
548        checks for such things as part of the documentation building process.
549    
550    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
551        --match-limit and --recursion-limit options (added for 8.11). In
552        particular, this made one of the standard tests fail. (The integer value
553        went into the wrong half of a long int.)
554    
555    3.  If the --colour option was given to pcregrep with -v (invert match), it
556        did strange things, either producing crazy output, or crashing. It should,
557        of course, ignore a request for colour when reporting lines that do not
558        match.
559    
560    4.  Another pcregrep bug caused similar problems if --colour was specified with
561        -M (multiline) and the pattern match finished with a line ending.
562    
563    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
564        matched in multiline mode, the following line was shown as part of the
565        match. This seems wrong, so I have changed it.
566    
567    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
568        the check for further matches in the same line (so they could be coloured)
569        to overrun the end of the current line. If another match was found, it was
570        incorrectly shown (and then shown again when found in the next line).
571    
572    7.  If pcregrep was compiled under Windows, there was a reference to the
573        function pcregrep_exit() before it was defined. I am assuming this was
574        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
575        reported by a user. I've moved the definition above the reference.
576    
577    
578    Version 8.11 10-Dec-2010
579    ------------------------
580    
581    1.  (*THEN) was not working properly if there were untried alternatives prior
582        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
583        backtracked to try for "b" instead of moving to the next alternative branch
584        at the same level (in this case, to look for "c"). The Perl documentation
585        is clear that when (*THEN) is backtracked onto, it goes to the "next
586        alternative in the innermost enclosing group".
587    
588    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
589        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
590        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
591        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
592        (*THEN).
593    
594    3.  If \s appeared in a character class, it removed the VT character from
595        the class, even if it had been included by some previous item, for example
596        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
597        of \s, but is part of the POSIX "space" class.)
598    
599    4.  A partial match never returns an empty string (because you can always
600        match an empty string at the end of the subject); however the checking for
601        an empty string was starting at the "start of match" point. This has been
602        changed to the "earliest inspected character" point, because the returned
603        data for a partial match starts at this character. This means that, for
604        example, /(?<=abc)def/ gives a partial match for the subject "abc"
605        (previously it gave "no match").
606    
607    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
608        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
609        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
610        has an implication that the given string is incomplete (because a partial
611        match is preferred over a full match). For this reason, these items now
612        give a partial match in this situation. [Aside: previously, the one case
613        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
614        match rather than a full match, which was wrong by the old rules, but is
615        now correct.]
616    
617    6.  There was a bug in the handling of #-introduced comments, recognized when
618        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
619        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
620        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
621        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
622        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
623        places in pcre_compile().
624    
625    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
626        comments when looking ahead for named forward references to subpatterns,
627        the only newline sequence it recognized was NL. It now handles newlines
628        according to the set newline convention.
629    
630    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
631        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
632        cater for a lack of strerror(). These oversights have been fixed.
633    
634    9.  Added --match-limit and --recursion-limit to pcregrep.
635    
636    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
637    
638    11. When the -o option was used, pcregrep was setting a return code of 1, even
639        when matches were found, and --line-buffered was not being honoured.
640    
641    12. Added an optional parentheses number to the -o and --only-matching options
642        of pcregrep.
643    
644    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
645        can match an empty string. The code to do it in pcretest and pcredemo
646        needed fixing:
647    
648        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
649            only one byte after an empty string match just before CRLF (this case
650            just got forgotten; "any" and "anycrlf" were OK).
651    
652        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
653            mode when an empty string match preceded an ASCII character followed by
654            a non-ASCII character. (The code for advancing by one character rather
655            than one byte was nonsense.)
656    
657        (c) The pcredemo.c sample program did not have any code at all to handle
658            the cases when CRLF is a valid newline sequence.
659    
660    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
661        as a starting offset was within the subject string. There is now a new
662        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
663        negative or greater than the length of the string. In order to test this,
664        pcretest is extended to allow the setting of negative starting offsets.
665    
666    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
667        starting offset points to the beginning of a UTF-8 character was
668        unnecessarily clumsy. I tidied it up.
669    
670    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
671        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
672    
673    17. Nobody had reported that the --include_dir option, which was added in
674        release 7.7 should have been called --include-dir (hyphen, not underscore)
675        for compatibility with GNU grep. I have changed it to --include-dir, but
676        left --include_dir as an undocumented synonym, and the same for
677        --exclude-dir, though that is not available in GNU grep, at least as of
678        release 2.5.4.
679    
680    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
681        characters from a string of bytes) have been redefined so as not to use
682        loops, in order to improve performance in some environments. At the same
683        time, I abstracted some of the common code into auxiliary macros to save
684        repetition (this should not affect the compiled code).
685    
686    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
687        compile-time error is now given if \c is not followed by an ASCII
688        character, that is, a byte less than 128. (In EBCDIC mode, the code is
689        different, and any byte value is allowed.)
690    
691    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
692        START_OPTIMIZE option, which is now allowed at compile time - but just
693        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
694        to pcregrep and other applications that have no direct access to PCRE
695        options. The new /Y option in pcretest sets this option when calling
696        pcre_compile().
697    
698    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
699        back references. Groups containing recursive back references were forced to
700        be atomic by that change, but in the case of named groups, the amount of
701        memory required was incorrectly computed, leading to "Failed: internal
702        error: code overflow". This has been fixed.
703    
704    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
705        pcretest.c, to avoid build problems in some Borland environments.
706    
707    
708    Version 8.10 25-Jun-2010
709    ------------------------
710    
711    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
712        THEN.
713    
714    2.  (*ACCEPT) was not working when inside an atomic group.
715    
716    3.  Inside a character class, \B is treated as a literal by default, but
717        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
718        causes the error). The code is unchanged, but I tidied the documentation.
719    
720    4.  Inside a character class, PCRE always treated \R and \X as literals,
721        whereas Perl faults them if its -w option is set. I have changed PCRE so
722        that it faults them when PCRE_EXTRA is set.
723    
724    5.  Added support for \N, which always matches any character other than
725        newline. (It is the same as "." when PCRE_DOTALL is not set.)
726    
727    6.  When compiling pcregrep with newer versions of gcc which may have
728        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
729        declared with attribute warn_unused_result" were given. Just casting the
730        result to (void) does not stop the warnings; a more elaborate fudge is
731        needed. I've used a macro to implement this.
732    
733    7.  Minor change to pcretest.c to avoid a compiler warning.
734    
735    8.  Added four artifical Unicode properties to help with an option to make
736        \s etc use properties (see next item). The new properties are: Xan
737        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
738    
739    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
740        use Unicode properties. (*UCP) at the start of a pattern can be used to set
741        this option. Modified pcretest to add /W to test this facility. Added
742        REG_UCP to make it available via the POSIX interface.
743    
744    10. Added --line-buffered to pcregrep.
745    
746    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
747        studied, and the match started with a letter with a code point greater than
748        127 whose first byte was different to the first byte of the other case of
749        the letter, the other case of this starting letter was not recognized
750        (#976).
751    
752    12. If a pattern that was studied started with a repeated Unicode property
753        test, for example, \p{Nd}+, there was the theoretical possibility of
754        setting up an incorrect bitmap of starting bytes, but fortunately it could
755        not have actually happened in practice until change 8 above was made (it
756        added property types that matched character-matching opcodes).
757    
758    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
759        possible starting bytes for non-anchored patterns.
760    
761    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
762        \R, and also a number of cases that involve Unicode properties, both
763        explicit and implicit when PCRE_UCP is set.
764    
765    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
766        input, it could crash or give wrong results if characters with values
767        greater than 0xc0 were present in the subject string. (Detail: it assumed
768        UTF-8 input when processing these items.)
769    
770    16. Added a lot of (int) casts to avoid compiler warnings in systems where
771        size_t is 64-bit (#991).
772    
773    17. Added a check for running out of memory when PCRE is compiled with
774        --disable-stack-for-recursion (#990).
775    
776    18. If the last data line in a file for pcretest does not have a newline on
777        the end, a newline was missing in the output.
778    
779    19. The default pcre_chartables.c file recognizes only ASCII characters (values
780        less than 128) in its various bitmaps. However, there is a facility for
781        generating tables according to the current locale when PCRE is compiled. It
782        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
783        characters, are recognized by isspace() and therefore were getting set in
784        these tables, and indeed these tables seem to approximate to ISO 8859. This
785        caused a problem in UTF-8 mode when pcre_study() was used to create a list
786        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
787        which of course cannot start UTF-8 characters. I have changed the code so
788        that only real ASCII characters (less than 128) and the correct starting
789        bytes for UTF-8 encodings are set for characters greater than 127 when in
790        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
791        altogether.)
792    
793    20. Added the /T option to pcretest so as to be able to run tests with non-
794        standard character tables, thus making it possible to include the tests
795        used for 19 above in the standard set of tests.
796    
797    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
798        reference to a subpattern the other side of a comment that contains an
799        opening parenthesis caused either an internal compiling error, or a
800        reference to the wrong subpattern.
801    
802    
803    Version 8.02 19-Mar-2010
804    ------------------------
805    
806    1.  The Unicode data tables have been updated to Unicode 5.2.0.
807    
808    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
809        configured.
810    
811    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
812        original author of that file, following a query about its status.
813    
814    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
815        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
816    
817    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
818        quantifier applied to a forward-referencing subroutine call, could compile
819        incorrect code or give the error "internal error: previously-checked
820        referenced subpattern not found".
821    
822    6.  Both MS Visual Studio and Symbian OS have problems with initializing
823        variables to point to external functions. For these systems, therefore,
824        pcre_malloc etc. are now initialized to local functions that call the
825        relevant global functions.
826    
827    7.  There were two entries missing in the vectors called coptable and poptable
828        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
829        I've fixed the data, and added a kludgy way of testing at compile time that
830        the lengths are correct (equal to the number of opcodes).
831    
832    8.  Following on from 7, I added a similar kludge to check the length of the
833        eint vector in pcreposix.c.
834    
835    9.  Error texts for pcre_compile() are held as one long string to avoid too
836        much relocation at load time. To find a text, the string is searched,
837        counting zeros. There was no check for running off the end of the string,
838        which could happen if a new error number was added without updating the
839        string.
840    
841    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
842    
843    11. \K was not working if it appeared in an atomic group or in a group that
844        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
845        \K is "not well defined" if used in an assertion. PCRE now accepts it if
846        the assertion is positive, but not if it is negative.
847    
848    12. Change 11 fortuitously reduced the size of the stack frame used in the
849        "match()" function of pcre_exec.c by one pointer. Forthcoming
850        implementation of support for (*MARK) will need an extra pointer on the
851        stack; I have reserved it now, so that the stack frame size does not
852        decrease.
853    
854    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
855        item in branch that calls a recursion is a subroutine call - as in the
856        second branch in the above example - was incorrectly given the compile-
857        time error "recursive call could loop indefinitely" because pcre_compile()
858        was not correctly checking the subroutine for matching a non-empty string.
859    
860    14. The checks for overrunning compiling workspace could trigger after an
861        overrun had occurred. This is a "should never occur" error, but it can be
862        triggered by pathological patterns such as hundreds of nested parentheses.
863        The checks now trigger 100 bytes before the end of the workspace.
864    
865    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
866    
867    
868    Version 8.01 19-Jan-2010
869    ------------------------
870    
871    1.  If a pattern contained a conditional subpattern with only one branch (in
872        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
873        computed the wrong minimum data length (which is of course zero for such
874        subpatterns). This could cause incorrect "no match" results.
875    
876    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
877        the pattern is reset in the first branch, pcre_compile() failed with
878        "internal error: code overflow at offset...". This happened only when
879        the reset was to the original external option setting. (An optimization
880        abstracts leading options settings into an external setting, which was the
881        cause of this.)
882    
883    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
884        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
885        assertion pattern did not match (meaning that the assertion was true), it
886        was incorrectly treated as false if the SKIP had been reached during the
887        matching. This also applied to assertions used as conditions.
888    
889    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
890        assertion subpattern, including such a pattern used as a condition,
891        unpredictable results occurred, instead of the error return
892        PCRE_ERROR_DFA_UITEM.
893    
894    5.  The C++ GlobalReplace function was not working like Perl for the special
895        situation when an empty string is matched. It now does the fancy magic
896        stuff that is necessary.
897    
898    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
899        removed. (These were left over from very, very early versions of PCRE.)
900    
901    7.  Some cosmetic changes to the code to make life easier when compiling it
902        as part of something else:
903    
904        (a) Change DEBUG to PCRE_DEBUG.
905    
906        (b) In pcre_compile(), rename the member of the "branch_chain" structure
907            called "current" as "current_branch", to prevent a collision with the
908            Linux macro when compiled as a kernel module.
909    
910        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
911            prevent a collision with the Linux macro when compiled as a kernel
912            module.
913    
914    8.  In pcre_compile() there are some checks for integer overflows that used to
915        cast potentially large values to (double). This has been changed to that
916        when building, a check for int64_t is made, and if it is found, it is used
917        instead, thus avoiding the use of floating point arithmetic. (There is no
918        other use of FP in PCRE.) If int64_t is not found, the fallback is to
919        double.
920    
921    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
922        2005 (difference between two addresses compared to an unsigned value).
923    
924    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
925        custom one, because of the following reported problem in Windows:
926    
927          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
928              under Win32.
929          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
930              therefore missing the function definition.
931          - The compiler thus generates a "C" signature for the test function.
932          - The linker fails to find the "C" function.
933          - PCRE fails to configure if asked to do so against libbz2.
934    
935    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
936        messages were output:
937    
938          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
939          rerunning libtoolize, to keep the correct libtool macros in-tree.
940          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
941    
942        I have done both of these things.
943    
944    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
945        most of the time, it *can* run out if it is given a pattern that contains a
946        runaway infinite recursion. I updated the discussion in the pcrestack man
947        page.
948    
949    13. Now that we have gone to the x.xx style of version numbers, the minor
950        version may start with zero. Using 08 or 09 is a bad idea because users
951        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
952        interpreted as invalid octal numbers. I've updated the previous comment in
953        configure.ac, and also added a check that gives an error if 08 or 09 are
954        used.
955    
956    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
957        causing partial matching to fail when the end of the subject matched \W
958        in a UTF-8 pattern where \W was quantified with a minimum of 3.
959    
960    15. There were some discrepancies between the declarations in pcre_internal.h
961        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
962        their definitions. The declarations used "const uschar *" and the
963        definitions used USPTR. Even though USPTR is normally defined as "const
964        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
965        reported that: "This difference in casting confuses some C++ compilers, for
966        example, SunCC recognizes above declarations as different functions and
967        generates broken code for hbpcre." I have changed the declarations to use
968        USPTR.
969    
970    16. GNU libtool is named differently on some systems. The autogen.sh script now
971        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
972        (FreeBSD).
973    
974    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
975        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
976        comment: "Figure out how to create a longlong from a string: strtoll and
977        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
978        instance, but it only takes 2 args instead of 3!"
979    
980    18. A subtle bug concerned with back references has been fixed by a change of
981        specification, with a corresponding code fix. A pattern such as
982        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
983        refers, was giving matches when it shouldn't. For example, xa=xaaa would
984        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
985        same bug. Such groups have to be quantified to be useful, or contained
986        inside another quantified group. (If there's no repetition, the reference
987        can never match.) The problem arises because, having left the group and
988        moved on to the rest of the pattern, a later failure that backtracks into
989        the group uses the captured value from the final iteration of the group
990        rather than the correct earlier one. I have fixed this in PCRE by forcing
991        any group that contains a reference to itself to be an atomic group; that
992        is, there cannot be any backtracking into it once it has completed. This is
993        similar to recursive and subroutine calls.
994    
995    
996    Version 8.00 19-Oct-09
997    ----------------------
998    
999    1.  The table for translating pcre_compile() error codes into POSIX error codes
1000        was out-of-date, and there was no check on the pcre_compile() error code
1001        being within the table. This could lead to an OK return being given in
1002        error.
1003    
1004    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1005        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1006        in a Windows environment.
1007    
1008    3.  The pcregrep --count option prints the count for each file even when it is
1009        zero, as does GNU grep. However, pcregrep was also printing all files when
1010        --files-with-matches was added. Now, when both options are given, it prints
1011        counts only for those files that have at least one match. (GNU grep just
1012        prints the file name in this circumstance, but including the count seems
1013        more useful - otherwise, why use --count?) Also ensured that the
1014        combination -clh just lists non-zero counts, with no names.
1015    
1016    4.  The long form of the pcregrep -F option was incorrectly implemented as
1017        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1018        but it seems right to fix it, and I didn't think it was worth preserving
1019        the old behaviour.
1020    
1021    5.  The command line items --regex=pattern and --regexp=pattern were not
1022        recognized by pcregrep, which required --regex pattern or --regexp pattern
1023        (with a space rather than an '='). The man page documented the '=' forms,
1024        which are compatible with GNU grep; these now work.
1025    
1026    6.  No libpcreposix.pc file was created for pkg-config; there was just
1027        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1028    
1029    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1030        when UCP support is not needed, by modifying the Python script that
1031        generates it from Unicode data files. This should not matter if the module
1032        is correctly used as a library, but I received one complaint about 50K of
1033        unwanted data. My guess is that the person linked everything into his
1034        program rather than using a library. Anyway, it does no harm.
1035    
1036    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1037        was a minimum greater than 1 for a wide character in a possessive
1038        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1039        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1040        character. Chaos in the form of incorrect output or a compiling loop could
1041        result.
1042    
1043    9.  The restrictions on what a pattern can contain when partial matching is
1044        requested for pcre_exec() have been removed. All patterns can now be
1045        partially matched by this function. In addition, if there are at least two
1046        slots in the offset vector, the offset of the earliest inspected character
1047        for the match and the offset of the end of the subject are set in them when
1048        PCRE_ERROR_PARTIAL is returned.
1049    
1050    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1051        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1052        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1053        and may be more useful for multi-segment matching.
1054    
1055    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1056        used to be given if ever the end of the subject was reached; now it is
1057        given only if matching could not proceed because another character was
1058        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1059        string "Z", which now yields "no match" instead of "partial match". In the
1060        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1061        final character ended with (*FAIL).
1062    
1063    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1064        if the pattern had a "must contain" character that was already found in the
1065        earlier partial match, unless partial matching was again requested. For
1066        example, with the pattern /dog.(body)?/, the "must contain" character is
1067        "g". If the first part-match was for the string "dog", restarting with
1068        "sbody" failed. This bug has been fixed.
1069    
1070    13. The string returned by pcre_dfa_exec() after a partial match has been
1071        changed so that it starts at the first inspected character rather than the
1072        first character of the match. This makes a difference only if the pattern
1073        starts with a lookbehind assertion or \b or \B (\K is not supported by
1074        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1075        matching functions compatible, and I think it's the right thing to do.
1076    
1077    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1078        so that the demonstration program is easily available in environments where
1079        PCRE has not been installed from source.
1080    
1081    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1082        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1083        library.
1084    
1085    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1086        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1087        is not the first non-POSIX option to be added. Clearly some people find
1088        these options useful.
1089    
1090    17. If a caller to the POSIX matching function regexec() passes a non-zero
1091        value for nmatch with a NULL value for pmatch, the value of
1092        nmatch is forced to zero.
1093    
1094    18. RunGrepTest did not have a test for the availability of the -u option of
1095        the diff command, as RunTest does. It now checks in the same way as
1096        RunTest, and also checks for the -b option.
1097    
1098    19. If an odd number of negated classes containing just a single character
1099        interposed, within parentheses, between a forward reference to a named
1100        subpattern and the definition of the subpattern, compilation crashed with
1101        an internal error, complaining that it could not find the referenced
1102        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1103        [The bug was that it was starting one character too far in when skipping
1104        over the character class, thus treating the ] as data rather than
1105        terminating the class. This meant it could skip too much.]
1106    
1107    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1108        /g option in pcretest when the pattern contains \K, which makes it possible
1109        to have an empty string match not at the start, even when the pattern is
1110        anchored. Updated pcretest and pcredemo to use this option.
1111    
1112    21. If the maximum number of capturing subpatterns in a recursion was greater
1113        than the maximum at the outer level, the higher number was returned, but
1114        with unset values at the outer level. The correct (outer level) value is
1115        now given.
1116    
1117    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1118        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1119        make it do so. The string so far is captured, making this feature
1120        compatible with Perl.
1121    
1122    23. The tests have been re-organized, adding tests 11 and 12, to make it
1123        possible to check the Perl 5.10 features against Perl 5.10.
1124    
1125    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1126        pattern matches a fixed length string. PCRE did not allow this; now it
1127        does. Neither allows recursion.
1128    
1129    25. I finally figured out how to implement a request to provide the minimum
1130        length of subject string that was needed in order to match a given pattern.
1131        (It was back references and recursion that I had previously got hung up
1132        on.) This code has now been added to pcre_study(); it finds a lower bound
1133        to the length of subject needed. It is not necessarily the greatest lower
1134        bound, but using it to avoid searching strings that are too short does give
1135        some useful speed-ups. The value is available to calling programs via
1136        pcre_fullinfo().
1137    
1138    26. While implementing 25, I discovered to my embarrassment that pcretest had
1139        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1140        study optimizations had never been tested with that matching function.
1141        Oops. What is worse, even when it was passed study data, there was a bug in
1142        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1143        were also very few tests of studied patterns with pcre_dfa_exec().
1144    
1145    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1146        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1147        on the other side of the coin, they are no longer allowed to have different
1148        names, because these cannot be distinguished in PCRE, and this has caused
1149        confusion. (This is a difference from Perl.)
1150    
1151    28. When duplicate subpattern names are present (necessarily with different
1152        numbers, as required by 27 above), and a test is made by name in a
1153        conditional pattern, either for a subpattern having been matched, or for
1154        recursion in such a pattern, all the associated numbered subpatterns are
1155        tested, and the overall condition is true if the condition is true for any
1156        one of them. This is the way Perl works, and is also more like the way
1157        testing by number works.
1158    
1159    
1160    Version 7.9 11-Apr-09
1161    ---------------------
1162    
1163    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1164        (pcretest), all targets were linked against these libraries. This included
1165        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1166        libraries. This caused unwanted dependencies to be created. This problem
1167        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1168        pcretest is linked with readline.
1169    
1170    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1171        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1172        moved outside it again, because FALSE and TRUE are already defined in AIX,
1173        but BOOL is not.
1174    
1175    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1176        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1177    
1178    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1179        hyphens) following file names and line numbers when outputting matching
1180        lines. This is not true; no spaces are inserted. I have also clarified the
1181        wording for the --colour (or --color) option.
1182    
1183    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1184        was not coloured; this is different to GNU grep, so I have changed it to be
1185        the same.
1186    
1187    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1188        each matching line was coloured. Now it goes on to look for further matches
1189        of any of the test patterns, which is the same behaviour as GNU grep.
1190    
1191    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1192        doesn't make sense to accept an empty string match in pcregrep, so I have
1193        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1194        seems to be how GNU grep behaves.
1195    
1196    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1197        start or after a newline", because the conditional assertion was not being
1198        correctly handled. The rule now is that both the assertion and what follows
1199        in the first alternative must satisfy the test.
1200    
1201    9.  If auto-callout was enabled in a pattern with a conditional group whose
1202        condition was an assertion, PCRE could crash during matching, both with
1203        pcre_exec() and pcre_dfa_exec().
1204    
1205    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1206        used for matching.
1207    
1208    11. Unicode property support in character classes was not working for
1209        characters (bytes) greater than 127 when not in UTF-8 mode.
1210    
1211    12. Added the -M command line option to pcretest.
1212    
1213    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1214    
1215    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1216    
1217    16. Added comments and documentation about mis-use of no_arg in the C++
1218        wrapper.
1219    
1220    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1221        from Martin Jerabek that uses macro names for all relevant character and
1222        string constants.
1223    
1224    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1225        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1226        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1227        these, but not everybody uses configure.
1228    
1229    19. A conditional group that had only one branch was not being correctly
1230        recognized as an item that could match an empty string. This meant that an
1231        enclosing group might also not be so recognized, causing infinite looping
1232        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1233        with the subject "ab", where knowledge that the repeated group can match
1234        nothing is needed in order to break the loop.
1235    
1236    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1237        exec(), but without supplying a callout function, matching went wrong.
1238    
1239    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1240        leak if the size of the offset vector was greater than 30. When the vector
1241        is smaller, the saved offsets during recursion go onto a local stack
1242        vector, but for larger vectors malloc() is used. It was failing to free
1243        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1244        error, in fact).
1245    
1246    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1247        heapframe that is used only when UTF-8 support is enabled. This caused no
1248        problem, but was untidy.
1249    
1250    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1251        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1252        included within another project.
1253    
1254    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1255        slightly modified by me:
1256    
1257          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1258              not building pcregrep.
1259    
1260          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1261              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1262    
1263    25. Forward references, both numeric and by name, in patterns that made use of
1264        duplicate group numbers, could behave incorrectly or give incorrect errors,
1265        because when scanning forward to find the reference group, PCRE was not
1266        taking into account the duplicate group numbers. A pattern such as
1267        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1268    
1269    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1270        the feature of a custom pointer more persuasive (as requested by a user).
1271    
1272    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1273        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1274        pre-defined.
1275    
1276    28. Added support for (*UTF8) at the start of a pattern.
1277    
1278    29. Arrange for flags added by the "release type" setting in CMake to be shown
1279        in the configuration summary.
1280    
1281    
1282    Version 7.8 05-Sep-08
1283    ---------------------
1284    
1285    1.  Replaced UCP searching code with optimized version as implemented for Ad
1286        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1287        stage table and inline lookup instead of a function, giving speed ups of 2
1288        to 5 times on some simple patterns that I tested. Permission was given to
1289        distribute the MultiStage2.py script that generates the tables (it's not in
1290        the tarball, but is in the Subversion repository).
1291    
1292    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1293        scripts.
1294    
1295    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1296        a group with a zero qualifier. The result of the study could be incorrect,
1297        or the function might crash, depending on the pattern.
1298    
1299    4.  Caseless matching was not working for non-ASCII characters in back
1300        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1301        It now works when Unicode Property Support is available.
1302    
1303    5.  In pcretest, an escape such as \x{de} in the data was always generating
1304        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1305        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1306        truncation.
1307    
1308    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1309    
1310    7.  Added two (int) casts to pcregrep when printing the difference of two
1311        pointers, in case they are 64-bit values.
1312    
1313    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1314        test 2 if it fails.
1315    
1316    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1317        and a #define of that name to empty if it is not externally set. This is to
1318        allow users of MSVC to set it if necessary.
1319    
1320    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1321        the convenience functions in the pcre_get.c source file.
1322    
1323    11. An option change at the start of a pattern that had top-level alternatives
1324        could cause overwriting and/or a crash. This command provoked a crash in
1325        some environments:
1326    
1327          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1328    
1329        This potential security problem was recorded as CVE-2008-2371.
1330    
1331    12. For a pattern where the match had to start at the beginning or immediately
1332        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1333        pcre_dfa_exec() could read past the end of the passed subject if there was
1334        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1335        pcretest so that it places the subject at the end of its malloc-ed buffer.
1336    
1337    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1338        exec() might read past the end of the data buffer in UTF-8 mode.
1339    
1340    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1341        the data contained the byte 0x85 as part of a UTF-8 character within its
1342        first line. This applied both to normal and DFA matching.
1343    
1344    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1345        /^[^d]*?$/8 failed to match "abc".
1346    
1347    16. Added a missing copyright notice to pcrecpp_internal.h.
1348    
1349    17. Make it more clear in the documentation that values returned from
1350        pcre_exec() in ovector are byte offsets, not character counts.
1351    
1352    18. Tidied a few places to stop certain compilers from issuing warnings.
1353    
1354    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1355        supplied by Stefan Weber. I made a further small update for 7.8 because
1356        there is a change of source arrangements: the pcre_searchfuncs.c module is
1357        replaced by pcre_ucd.c.
1358    
1359    
1360    Version 7.7 07-May-08
1361    ---------------------
1362    
1363    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1364        a string to a long long, pretend we don't even have a long long." This is
1365        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1366    
1367    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1368        pre-7.6 versions, which defined a global no_arg variable instead of putting
1369        it in the RE class. (See also #8 below.)
1370    
1371    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1372        Lopes.
1373    
1374    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1375    
1376        (1) The include/exclude patterns were being applied to the whole pathnames
1377            of files, instead of just to the final components.
1378    
1379        (2) If there was more than one level of directory, the subdirectories were
1380            skipped unless they satisfied the include/exclude conditions. This is
1381            inconsistent with GNU grep (and could even be seen as contrary to the
1382            pcregrep specification - which I improved to make it absolutely clear).
1383            The action now is always to scan all levels of directory, and just
1384            apply the include/exclude patterns to regular files.
1385    
1386    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1387        --exclude_dir in the tests to avoid scanning .svn directories.
1388    
1389    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1390        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1391        doesn't support NULs in patterns.
1392    
1393    7.  Added some missing "const"s to declarations of static tables in
1394        pcre_compile.c and pcre_dfa_exec.c.
1395    
1396    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1397        caused by fix #2  above. (Subsequently also a second patch to fix the
1398        first patch. And a third patch - this was a messy problem.)
1399    
1400    9.  Applied Craig's patch to remove the use of push_back().
1401    
1402    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1403        matching function regexec().
1404    
1405    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1406        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1407        references. PCRE supports relative numbers with this syntax (I don't think
1408        Oniguruma does).
1409    
1410    12. Previously, a group with a zero repeat such as (...){0} was completely
1411        omitted from the compiled regex. However, this means that if the group
1412        was called as a subroutine from elsewhere in the pattern, things went wrong
1413        (an internal error was given). Such groups are now left in the compiled
1414        pattern, with a new opcode that causes them to be skipped at execution
1415        time.
1416    
1417    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1418        to the way PCRE behaves:
1419    
1420        (a) A lone ] character is dis-allowed (Perl treats it as data).
1421    
1422        (b) A back reference to an unmatched subpattern matches an empty string
1423            (Perl fails the current match path).
1424    
1425        (c) A data ] in a character class must be notated as \] because if the
1426            first data character in a class is ], it defines an empty class. (In
1427            Perl it is not possible to have an empty class.) The empty class []
1428            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1429            The negative empty class [^] matches any one character, independently
1430            of the DOTALL setting.
1431    
1432    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1433        non-existent subpattern following a character class starting with ']' and
1434        containing () gave an internal compiling error instead of "reference to
1435        non-existent subpattern". Fortunately, when the pattern did exist, the
1436        compiled code was correct. (When scanning forwards to check for the
1437        existencd of the subpattern, it was treating the data ']' as terminating
1438        the class, so got the count wrong. When actually compiling, the reference
1439        was subsequently set up correctly.)
1440    
1441    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1442        it was being rejected as not supported by pcre_dfa_exec(), even though
1443        other assertions are supported. I have made pcre_dfa_exec() support
1444        (*FAIL).
1445    
1446    16. The implementation of 13c above involved the invention of a new opcode,
1447        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1448        cannot be changed at match time, I realized I could make a small
1449        improvement to matching performance by compiling OP_ALLANY instead of
1450        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1451        on the OP_ANY path.
1452    
1453    17. Compiling pcretest on Windows with readline support failed without the
1454        following two fixes: (1) Make the unistd.h include conditional on
1455        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1456    
1457    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1458        ncurses library to be included for pcretest when ReadLine support is
1459        requested, but also to allow for it to be overridden. This patch came from
1460        Daniel Bergström.
1461    
1462    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1463        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1464        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1465        spotting this.
1466    
1467    
1468    Version 7.6 28-Jan-08
1469    ---------------------
1470    
1471    1.  A character class containing a very large number of characters with
1472        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1473        overflow.
1474    
1475    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1476        HAVE_LONG_LONG is not defined.
1477    
1478    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1479        bring them up to date and include new features. This patch includes:
1480    
1481        - Fixed PH's badly added libz and libbz2 support.
1482        - Fixed a problem with static linking.
1483        - Added pcredemo. [But later removed - see 7 below.]
1484        - Fixed dftables problem and added an option.
1485        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1486            HAVE_LONG_LONG.
1487        - Added readline support for pcretest.
1488        - Added an listing of the option settings after cmake has run.
1489    
1490    4.  A user submitted a patch to Makefile that makes it easy to create
1491        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1492        Makefile.am that cause it to include this special target, without
1493        affecting anything else. Note that the same mingw target plus all
1494        the other distribution libraries and programs are now supported
1495        when configuring with CMake (see 6 below) instead of with
1496        Configure/Make.
1497    
1498    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1499        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1500        exported in the Windows port". It has not yet been confirmed that the patch
1501        solves the problem, but it does no harm.
1502    
1503    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1504        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1505        with CMake, and also correct the comment about stack recursion.
1506    
1507    7.  Remove the automatic building of pcredemo from the ./configure system and
1508        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1509        of a program that users should build themselves after PCRE is installed, so
1510        building it automatically is not really right. What is more, it gave
1511        trouble in some build environments.
1512    
1513    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1514    
1515    
1516    Version 7.5 10-Jan-08
1517    ---------------------
1518    
1519    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1520        values in parens when parsing an RE using the C++ wrapper."
1521    
1522    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1523        Characters greater than 255 were excluded from the class instead of being
1524        included.
1525    
1526    3.  The same bug as (2) above applied to negated POSIX classes such as
1527        [:^space:].
1528    
1529    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1530        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1531        I have changed it.
1532    
1533    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1534        first named subpattern) and a construct such as (?&a) would reference the
1535        first named subpattern whose name started with "a" (in other words, the
1536        length check was missing). Both these problems are fixed. "Subpattern name
1537        expected" is now given for (?&) (a zero-length name), and this patch also
1538        makes it give the same error for \k'' (previously it complained that that
1539        was a reference to a non-existent subpattern).
1540    
1541    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1542        this is right because (?- can be followed by option settings as well as by
1543        digits. I have, however, made the messages clearer.
1544    
1545    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1546        than the number used in the conditional) now cause a compile-time error.
1547        This is actually not compatible with Perl, which accepts such patterns, but
1548        treats the conditional as always being FALSE (as PCRE used to), but it
1549        seems to me that giving a diagnostic is better.
1550    
1551    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1552        and messages.
1553    
1554    9.  Fix two occurrences of "backslash" in comments that should have been
1555        "backspace".
1556    
1557    10. Remove two redundant lines of code that can never be obeyed (their function
1558        was moved elsewhere).
1559    
1560    11. The program that makes PCRE's Unicode character property table had a bug
1561        which caused it to generate incorrect table entries for sequences of
1562        characters that have the same character type, but are in different scripts.
1563        It amalgamated them into a single range, with the script of the first of
1564        them. In other words, some characters were in the wrong script. There were
1565        thirteen such cases, affecting characters in the following ranges:
1566    
1567          U+002b0 - U+002c1
1568          U+0060c - U+0060d
1569          U+0061e - U+00612
1570          U+0064b - U+0065e
1571          U+0074d - U+0076d
1572          U+01800 - U+01805
1573          U+01d00 - U+01d77
1574          U+01d9b - U+01dbf
1575          U+0200b - U+0200f
1576          U+030fc - U+030fe
1577          U+03260 - U+0327f
1578          U+0fb46 - U+0fbb1
1579          U+10450 - U+1049d
1580    
1581    12. The -o option (show only the matching part of a line) for pcregrep was not
1582        compatible with GNU grep in that, if there was more than one match in a
1583        line, it showed only the first of them. It now behaves in the same way as
1584        GNU grep.
1585    
1586    13. If the -o and -v options were combined for pcregrep, it printed a blank
1587        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1588        does the same. The return code can be used to tell if there were any
1589        non-matching lines.
1590    
1591    14. Added --file-offsets and --line-offsets to pcregrep.
1592    
1593    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1594        infinitely looping recursion. The bug was that positive lookaheads were not
1595        being skipped when checking for a possible empty match (negative lookaheads
1596        and both kinds of lookbehind were skipped).
1597    
1598    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1599        inclusion of <windows.h> to before rather than after the definition of
1600        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1601    
1602    17. Specifying a possessive quantifier with a specific limit for a Unicode
1603        character property caused pcre_compile() to compile bad code, which led at
1604        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1605        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1606        caused the error; without that there was no problem.
1607    
1608    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1609    
1610    19. Added --enable-pcretest-libreadline.
1611    
1612    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1613        RE::GlobalReplace(). As a result, the number of replacements returned was
1614        double what it should be. I removed one of the increments, but Craig sent a
1615        later patch that removed the other one (the right fix) and added unit tests
1616        that check the return values (which was not done before).
1617    
1618    21. Several CMake things:
1619    
1620        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1621            the names libpcre and libpcreposix, not just pcre and pcreposix.
1622    
1623        (2) The above change means that pcretest and pcregrep are now correctly
1624            linked with the newly-built libraries, not previously installed ones.
1625    
1626        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1627    
1628    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1629        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1630        UTF-8 newline character). The key issue is that the pattern starts .*;
1631        this means that the match must be either at the beginning, or after a
1632        newline. The bug was in the code for advancing after a failed match and
1633        checking that the new position followed a newline. It was not taking
1634        account of UTF-8 characters correctly.
1635    
1636    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1637        character classes. PCRE was not treating the sequence [:...:] as a
1638        character class unless the ... were all letters. Perl, however, seems to
1639        allow any characters between [: and :], though of course it rejects as
1640        unknown any "names" that contain non-letters, because all the known class
1641        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1642        for example, whereas PCRE did not - it did not recognize a POSIX character
1643        class. This seemed a bit dangerous, so the code has been changed to be
1644        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1645        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1646        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1647        Perl does, and where it didn't before.
1648    
1649    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1650        Windows environments %n is disabled by default.
1651    
1652    
1653    Version 7.4 21-Sep-07
1654    ---------------------
1655    
1656    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1657        means that a class such as [\s] counted as "explicit reference to CR or
1658        LF". That isn't really right - the whole point of the change was to try to
1659        help when there was an actual mention of one of the two characters. So now
1660        the change happens only if \r or \n (or a literal CR or LF) character is
1661        encountered.
1662    
1663    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1664        of both had grown to the point where there were only 3 bits left.
1665        Fortunately, there was spare space in the data structure, and so I have
1666        moved the internal flags into a new 16-bit field to free up more option
1667        bits.
1668    
1669    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1670        but did not set the internal JCHANGED flag - either of these is enough to
1671        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1672        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1673        start sets both bits.
1674    
1675    4.  Added options (at build time, compile time, exec time) to change \R from
1676        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1677    
1678    5.  doc/pcresyntax.html was missing from the distribution.
1679    
1680    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1681        compatibility, even though it is no longer used.
1682    
1683    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1684        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1685        windows.h file is present (where different names are used). [This was
1686        reversed later after testing - see 16 below.]
1687    
1688    8.  Changed all #include <config.h> to #include "config.h". There were also
1689        some further <pcre.h> cases that I changed to "pcre.h".
1690    
1691    9.  When pcregrep was used with the --colour option, it missed the line ending
1692        sequence off the lines that it output.
1693    
1694    10. It was pointed out to me that arrays of string pointers cause lots of
1695        relocations when a shared library is dynamically loaded. A technique of
1696        using a single long string with a table of offsets can drastically reduce
1697        these. I have refactored PCRE in four places to do this. The result is
1698        dramatic:
1699    
1700          Originally:                          290
1701          After changing UCP table:            187
1702          After changing error message table:   43
1703          After changing table of "verbs"       36
1704          After changing table of Posix names   22
1705    
1706        Thanks to the folks working on Gregex for glib for this insight.
1707    
1708    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1709        unicode-properties was also set.
1710    
1711    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1712    
1713    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1714        checked only for CRLF.
1715    
1716    14. Added casts to pcretest.c to avoid compiler warnings.
1717    
1718    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1719    
1720    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1721        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1722        entirely. This removes changes made in 7 above.
1723    
1724    17. The CMake files have been updated, and there is now more information about
1725        building with CMake in the NON-UNIX-USE document.
1726    
1727    
1728    Version 7.3 28-Aug-07
1729  ---------------------  ---------------------
1730    
1731   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 88  Version 7.3 05-Jul-07 Line 1812  Version 7.3 05-Jul-07
1812      past the start of the subject in the presence of bytes with the top bit      past the start of the subject in the presence of bytes with the top bit
1813      set, for example "\x8aBCD".      set, for example "\x8aBCD".
1814    
1815    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1816        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1817    
1818    14. Optimized (?!) to (*FAIL).
1819    
1820    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1821        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1822        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1823        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1824        does: it's just the validity check that is more restrictive.
1825    
1826    16. Inserted checks for integer overflows during escape sequence (backslash)
1827        processing, and also fixed erroneous offset values for syntax errors during
1828        backslash processing.
1829    
1830    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1831        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1832    
1833    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1834        caused an overrun.
1835    
1836    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1837        something other than just ASCII characters) inside a group that had an
1838        unlimited repeat caused a loop at compile time (while checking to see
1839        whether the group could match an empty string).
1840    
1841    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1842        [\P{Any}] did so. (Error in the code for printing property names.)
1843    
1844    21. An orphan \E inside a character class could cause a crash.
1845    
1846    22. A repeated capturing bracket such as (A)? could cause a wild memory
1847        reference during compilation.
1848    
1849    23. There are several functions in pcre_compile() that scan along a compiled
1850        expression for various reasons (e.g. to see if it's fixed length for look
1851        behind). There were bugs in these functions when a repeated \p or \P was
1852        present in the pattern. These operators have additional parameters compared
1853        with \d, etc, and these were not being taken into account when moving along
1854        the compiled data. Specifically:
1855    
1856        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1857            length.
1858    
1859        (b) An item such as \pL+ within a repeated group could cause crashes or
1860            loops.
1861    
1862        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1863            "reference to non-existent subpattern" error.
1864    
1865        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1866    
1867    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1868        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1869    
1870    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1871    
1872    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1873        character were causing crashes (broken optimization).
1874    
1875    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1876        \p or \P) caused a compile-time loop.
1877    
1878    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1879        break. For example, the unstudied pattern [\r\n]A does not match the string
1880        "\r\nA" because change 7.0/46 below moves the current point on by two
1881        characters after failing to match at the start. However, the pattern \nA
1882        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1883        the same is true. There doesn't seem any very clean way out of this, but
1884        what I have chosen to do makes the common cases work: PCRE now takes note
1885        of whether there can be an explicit match for \r or \n anywhere in the
1886        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1887        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1888        pattern has explicit CR or LF references.
1889    
1890    29. Added (*CR) etc for changing newline setting at start of pattern.
1891    
1892    
1893  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
1894  ---------------------  ---------------------

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