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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 12-Mar-07  Version 8.31
5    -----------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12        to unsigned type, result still unsigned" that was given by an MS compiler
13        on encountering the code "-sizeof(xxx)".
14    
15    4.  Partial matching support is added to the JIT compiler.
16    
17    
18    Version 8.30 04-February-2012
19    -----------------------------
20    
21    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
22        name is defined in ctype.h.
23    
24    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
25        only in quite long subpatterns.
26    
27    3.  Removed the function pcre_info(), which has been obsolete and deprecated
28        since it was replaced by pcre_fullinfo() in February 2000.
29    
30    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
31        match a (*MARK), and the match failed at the start of the subject, a
32        reference to memory before the start of the subject could occur. This bug
33        was introduced by fix 17 of release 8.21.
34    
35    5.  A reference to an unset group with zero minimum repetition was giving
36        totally wrong answers (in non-JavaScript-compatibility mode). For example,
37        /(another)?(\1?)test/ matched against "hello world test". This bug was
38        introduced in release 8.13.
39    
40    6.  Add support for 16-bit character strings (a large amount of work involving
41        many changes and refactorings).
42    
43    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
44        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
45        from a file.
46    
47    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
48        rounding is not applied in this particular case).
49    
50    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
51        if they appear, or are escaped, in patterns.
52    
53    10. Get rid of a number of -Wunused-but-set-variable warnings.
54    
55    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
56        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
57        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
58        also returns the mark "x". This bug applied to capturing parentheses,
59        non-capturing parentheses, and atomic parentheses. It also applied to some
60        assertions.
61    
62    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
63        information out of configure.ac instead of relying on pcre.h.generic, which
64        is not stored in the repository.
65    
66    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
67        -lreadline.
68    
69    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
70    
71    15. Applied Graycode's patch to put the top-level frame on the stack rather
72        than the heap when not using the stack for recursion. This gives a
73        performance improvement in many cases when recursion is not deep.
74    
75    16. Experimental code added to "pcretest -C" to output the stack frame size.
76    
77    
78    Version 8.21 12-Dec-2011
79    ------------------------
80    
81    1.  Updating the JIT compiler.
82    
83    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
84        are added as well.
85    
86    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
87        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
88        calling _pcre_jit_exec. Some extra comments are added.
89    
90    4.  (*MARK) settings inside atomic groups that do not contain any capturing
91        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
92        was introduced by change 18 for 8.20.
93    
94    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
95        ECMA-262 standard.
96    
97    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
98        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
99        This bug was probably introduced by change 9 of 8.13.
100    
101    7.  While fixing 6 above, I noticed that a number of other items were being
102        incorrectly rejected as "not fixed length". This arose partly because newer
103        opcodes had not been added to the fixed-length checking code. I have (a)
104        corrected the bug and added tests for these items, and (b) arranged for an
105        error to occur if an unknown opcode is encountered while checking for fixed
106        length instead of just assuming "not fixed length". The items that were
107        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
108        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
109        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
110    
111    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
112        being incorrectly compiled and would have given unpredicatble results.
113    
114    9.  A possessively repeated subpattern with minimum repeat count greater than
115        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
116        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
117        the first (A) could occur when it should not.
118    
119    10. Add a cast and remove a redundant test from the code.
120    
121    11. JIT should use pcre_malloc/pcre_free for allocation.
122    
123    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
124        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
125        is anything other than /usr, -L is still shown).
126    
127    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
128    
129    14. Perl does not support \N without a following name in a [] class; PCRE now
130        also gives an error.
131    
132    15. If a forward reference was repeated with an upper limit of around 2000,
133        it caused the error "internal error: overran compiling workspace". The
134        maximum number of forward references (including repeats) was limited by the
135        internal workspace, and dependent on the LINK_SIZE. The code has been
136        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
137        the default depends on LINK_SIZE. There is a new upper limit (for safety)
138        of around 200,000 forward references. While doing this, I also speeded up
139        the filling in of repeated forward references.
140    
141    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
142        incorrectly expecting the subject to contain another "a" after the start.
143    
144    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
145        in the match, the SKIP should be ignored. This was not happening; instead
146        the SKIP was being treated as NOMATCH. For patterns such as
147        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
148        tested.
149    
150    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
151        now much more compatible with Perl, in particular in cases where the result
152        is a non-match for a non-anchored pattern. For example, if
153        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
154        "m", where previously it did not return a name. A side effect of this
155        change is that for partial matches, the last encountered mark name is
156        returned, as for non matches. A number of tests that were previously not
157        Perl-compatible have been moved into the Perl-compatible test files. The
158        refactoring has had the pleasing side effect of removing one argument from
159        the match() function, thus reducing its stack requirements.
160    
161    19. If the /S+ option was used in pcretest to study a pattern using JIT,
162        subsequent uses of /S (without +) incorrectly behaved like /S+.
163    
164    21. Retrieve executable code size support for the JIT compiler and fixing
165        some warnings.
166    
167    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
168        not work when the shorter character appeared right at the end of the
169        subject string.
170    
171    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
172        systems.
173    
174    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
175        output it when the /M option is used in pcretest.
176    
177    25. The CheckMan script was not being included in the distribution. Also, added
178        an explicit "perl" to run Perl scripts from the PrepareRelease script
179        because this is reportedly needed in Windows.
180    
181    26. If study data was being save in a file and studying had not found a set of
182        "starts with" bytes for the pattern, the data written to the file (though
183        never used) was taken from uninitialized memory and so caused valgrind to
184        complain.
185    
186    27. Updated RunTest.bat as provided by Sheri Pierce.
187    
188    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
189    
190    29. Computation of memory usage for the table of capturing group names was
191        giving an unnecessarily large value.
192    
193    
194    Version 8.20 21-Oct-2011
195    ------------------------
196    
197    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
198        a POSIX class. After further experiments with Perl, which convinced me that
199        Perl has bugs and confusions, a closing square bracket is no longer allowed
200        in a POSIX name. This bug also affected patterns with classes that started
201        with full stops.
202    
203    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
204        captured substring, but while checking the failing first alternative,
205        substring 1 is temporarily captured. If the output vector supplied to
206        pcre_exec() was not big enough for this capture, the yield of the function
207        was still zero ("insufficient space for captured substrings"). This cannot
208        be totally fixed without adding another stack variable, which seems a lot
209        of expense for a edge case. However, I have improved the situation in cases
210        such as /(a)(b)x|abc/ matched against "abc", where the return code
211        indicates that fewer than the maximum number of slots in the ovector have
212        been set.
213    
214    3.  Related to (2) above: when there are more back references in a pattern than
215        slots in the output vector, pcre_exec() uses temporary memory during
216        matching, and copies in the captures as far as possible afterwards. It was
217        using the entire output vector, but this conflicts with the specification
218        that only 2/3 is used for passing back captured substrings. Now it uses
219        only the first 2/3, for compatibility. This is, of course, another edge
220        case.
221    
222    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
223        main code base, and can be used by building with --enable-jit. When this is
224        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
225        runtime --no-jit option is given.
226    
227    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
228        ovector, the return from the function was zero, implying that there were
229        other matches that did not fit. The correct "exactly full" value is now
230        returned.
231    
232    6.  If a subpattern that was called recursively or as a subroutine contained
233        (*PRUNE) or any other control that caused it to give a non-standard return,
234        invalid errors such as "Error -26 (nested recursion at the same subject
235        position)" or even infinite loops could occur.
236    
237    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
238        computing the minimum length on reaching *ACCEPT, and so ended up with the
239        wrong value of 1 rather than 0. Further investigation indicates that
240        computing a minimum subject length in the presence of *ACCEPT is difficult
241        (think back references, subroutine calls), and so I have changed the code
242        so that no minimum is registered for a pattern that contains *ACCEPT.
243    
244    8.  If (*THEN) was present in the first (true) branch of a conditional group,
245        it was not handled as intended. [But see 16 below.]
246    
247    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
248        Sheri Pierce.
249    
250    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
251        the first byte in a match must be "a".
252    
253    11. Change 17 for 8.13 increased the recursion depth for patterns like
254        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
255        pattern contains any instances of (*THEN). If it does not, the old
256        optimizations are restored. It would be nice to do this on a per-group
257        basis, but at the moment that is not feasible.
258    
259    12. In some environments, the output of pcretest -C is CRLF terminated. This
260        broke RunTest's code that checks for the link size. A single white space
261        character after the value is now allowed for.
262    
263    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
264        For "fr", it uses the Windows-specific input and output files.
265    
266    14. If (*THEN) appeared in a group that was called recursively or as a
267        subroutine, it did not work as intended. [But see next item.]
268    
269    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
270        pattern fragments (but not containing any | characters). If A and B are
271        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
272        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
273        D. In other words, Perl considers parentheses that do not contain any |
274        characters to be part of a surrounding alternative, whereas PCRE was
275        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
276        differently. PCRE now behaves in the same way as Perl, except in the case
277        of subroutine/recursion calls such as (?1) which have in any case always
278        been different (but PCRE had them first :-).
279    
280    16. Related to 15 above: Perl does not treat the | in a conditional group as
281        creating alternatives. Such a group is treated in the same way as an
282        ordinary group without any | characters when processing (*THEN). PCRE has
283        been changed to match Perl's behaviour.
284    
285    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
286        RunGrepTest script failed.
287    
288    18. Change 22 for version 13 caused atomic groups to use more stack. This is
289        inevitable for groups that contain captures, but it can lead to a lot of
290        stack use in large patterns. The old behaviour has been restored for atomic
291        groups that do not contain any capturing parentheses.
292    
293    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
294        suppress the check for a minimum subject length at run time. (If it was
295        given to pcre_exec() or pcre_dfa_exec() it did work.)
296    
297    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
298        fail to work when decoding hex characters in data strings in EBCDIC
299        environments.
300    
301    21. It appears that in at least one Mac OS environment, the isxdigit() function
302        is implemented as a macro that evaluates to its argument more than once,
303        contravening the C 90 Standard (I haven't checked a later standard). There
304        was an instance in pcretest which caused it to go wrong when processing
305        \x{...} escapes in subject strings. The has been rewritten to avoid using
306        things like p++ in the argument of isxdigit().
307    
308    
309    Version 8.13 16-Aug-2011
310    ------------------------
311    
312    1.  The Unicode data tables have been updated to Unicode 6.0.0.
313    
314    2.  Two minor typos in pcre_internal.h have been fixed.
315    
316    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
317        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
318        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
319    
320    4.  There were a number of related bugs in the code for matching backrefences
321        caselessly in UTF-8 mode when codes for the characters concerned were
322        different numbers of bytes. For example, U+023A and U+2C65 are an upper
323        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
324        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
325        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
326        2-byte code at the end of the subject (it thought there wasn't enough data
327        left).
328    
329    5.  Comprehensive information about what went wrong is now returned by
330        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
331        as the output vector has at least 2 elements. The offset of the start of
332        the failing character and a reason code are placed in the vector.
333    
334    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
335        now returned is for the first byte of the failing character, instead of the
336        last byte inspected. This is an incompatible change, but I hope it is small
337        enough not to be a problem. It makes the returned offset consistent with
338        pcre_exec() and pcre_dfa_exec().
339    
340    7.  pcretest now gives a text phrase as well as the error number when
341        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
342        failure, the offset and reason code are output.
343    
344    8.  When \R was used with a maximizing quantifier it failed to skip backwards
345        over a \r\n pair if the subsequent match failed. Instead, it just skipped
346        back over a single character (\n). This seems wrong (because it treated the
347        two characters as a single entity when going forwards), conflicts with the
348        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
349        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
350        has been changed.
351    
352    9.  Some internal refactoring has changed the processing so that the handling
353        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
354        time (the PCRE_DOTALL option was changed this way some time ago: version
355        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
356        which was always a bit of a fudge. It also means that there is one less
357        argument for the match() function, which reduces its stack requirements
358        slightly. This change also fixes an incompatibility with Perl: the pattern
359        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
360    
361    10. More internal refactoring has drastically reduced the number of recursive
362        calls to match() for possessively repeated groups such as (abc)++ when
363        using pcre_exec().
364    
365    11. While implementing 10, a number of bugs in the handling of groups were
366        discovered and fixed:
367    
368        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
369        (a|)*(?1) gave a compile-time internal error.
370        ((a|)+)+  did not notice that the outer group could match an empty string.
371        (^a|^)+   was not marked as anchored.
372        (.*a|.*)+ was not marked as matching at start or after a newline.
373    
374    12. Yet more internal refactoring has removed another argument from the match()
375        function. Special calls to this function are now indicated by setting a
376        value in a variable in the "match data" data block.
377    
378    13. Be more explicit in pcre_study() instead of relying on "default" for
379        opcodes that mean there is no starting character; this means that when new
380        ones are added and accidentally left out of pcre_study(), testing should
381        pick them up.
382    
383    14. The -s option of pcretest has been documented for ages as being an old
384        synonym of -m (show memory usage). I have changed it to mean "force study
385        for every regex", that is, assume /S for every regex. This is similar to -i
386        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
387        using it. It makes it easier to run collections of tests with and without
388        study enabled, and thereby test pcre_study() more easily. All the standard
389        tests are now run with and without -s (but some patterns can be marked as
390        "never study" - see 20 below).
391    
392    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
393        restoration of the capturing data to the outer values was not happening
394        correctly.
395    
396    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
397        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
398        pattern had matched an empty string, and so incorrectly returned a no
399        match.
400    
401    17. There was optimizing code for the last branch of non-capturing parentheses,
402        and also for the obeyed branch of a conditional subexpression, which used
403        tail recursion to cut down on stack usage. Unfortunately, now that there is
404        the possibility of (*THEN) occurring in these branches, tail recursion is
405        no longer possible because the return has to be checked for (*THEN). These
406        two optimizations have therefore been removed. [But see 8.20/11 above.]
407    
408    18. If a pattern containing \R was studied, it was assumed that \R always
409        matched two bytes, thus causing the minimum subject length to be
410        incorrectly computed because \R can also match just one byte.
411    
412    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
413        was incorrectly computed.
414    
415    20. If /S is present twice on a test pattern in pcretest input, it now
416        *disables* studying, thereby overriding the use of -s on the command line
417        (see 14 above). This is necessary for one or two tests to keep the output
418        identical in both cases.
419    
420    21. When (*ACCEPT) was used in an assertion that matched an empty string and
421        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
422    
423    22. When an atomic group that contained a capturing parenthesis was
424        successfully matched, but the branch in which it appeared failed, the
425        capturing was not being forgotten if a higher numbered group was later
426        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
427        group 1 to "a", when in fact it should be unset. This applied to multi-
428        branched capturing and non-capturing groups, repeated or not, and also to
429        positive assertions (capturing in negative assertions does not happen
430        in PCRE) and also to nested atomic groups.
431    
432    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
433        subject after a captured substring, to make it easier to tell which of a
434        number of identical substrings has been captured.
435    
436    24. The way atomic groups are processed by pcre_exec() has been changed so that
437        if they are repeated, backtracking one repetition now resets captured
438        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
439        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
440        "aaa". Previously, it would have been "a". As part of this code
441        refactoring, the way recursive calls are handled has also been changed.
442    
443    25. If an assertion condition captured any substrings, they were not passed
444        back unless some other capturing happened later. For example, if
445        (?(?=(a))a) was matched against "a", no capturing was returned.
446    
447    26. When studying a pattern that contained subroutine calls or assertions,
448        the code for finding the minimum length of a possible match was handling
449        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
450        group 1 called group 2 while simultaneously a separate group 2 called group
451        1). A stack overflow occurred in this case. I have fixed this by limiting
452        the recursion depth to 10.
453    
454    27. Updated RunTest.bat in the distribution to the version supplied by Tom
455        Fortmann. This supports explicit test numbers on the command line, and has
456        argument validation and error reporting.
457    
458    28. An instance of \X with an unlimited repeat could fail if at any point the
459        first character it looked at was a mark character.
460    
461    29. Some minor code refactoring concerning Unicode properties and scripts
462        should reduce the stack requirement of match() slightly.
463    
464    30. Added the '=' option to pcretest to check the setting of unused capturing
465        slots at the end of the pattern, which are documented as being -1, but are
466        not included in the return count.
467    
468    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
469        compiled something random. Now it gives a compile-time error (as does
470        Perl).
471    
472    32. A *MARK encountered during the processing of a positive assertion is now
473        recorded and passed back (compatible with Perl).
474    
475    33. If --only-matching or --colour was set on a pcregrep call whose pattern
476        had alternative anchored branches, the search for a second match in a line
477        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
478        matched the line "0102" twice. The same bug affected patterns that started
479        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
480        twice.
481    
482    34. Previously, PCRE did not allow quantification of assertions. However, Perl
483        does, and because of capturing effects, quantifying parenthesized
484        assertions may at times be useful. Quantifiers are now allowed for
485        parenthesized assertions.
486    
487    35. A minor code tidy in pcre_compile() when checking options for \R usage.
488    
489    36. \g was being checked for fancy things in a character class, when it should
490        just be a literal "g".
491    
492    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
493        appearance of a nested POSIX class supersedes an apparent external class.
494        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
495        unescaped square brackets may also appear as part of class names. For
496        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
497        more like Perl. (But see 8.20/1 above.)
498    
499    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
500        was because it thought it was \N{name}, which is not supported).
501    
502    39. Add minix to OS list not supporting the -S option in pcretest.
503    
504    40. PCRE tries to detect cases of infinite recursion at compile time, but it
505        cannot analyze patterns in sufficient detail to catch mutual recursions
506        such as ((?1))((?2)). There is now a runtime test that gives an error if a
507        subgroup is called recursively as a subpattern for a second time at the
508        same position in the subject string. In previous releases this might have
509        been caught by the recursion limit, or it might have run out of stack.
510    
511    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
512        happen only once. PCRE was, however incorrectly giving a compile time error
513        "recursive call could loop indefinitely" because it cannot analyze the
514        pattern in sufficient detail. The compile time test no longer happens when
515        PCRE is compiling a conditional subpattern, but actual runaway loops are
516        now caught at runtime (see 40 above).
517    
518    42. It seems that Perl allows any characters other than a closing parenthesis
519        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
520        has been changed to be the same.
521    
522    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
523        as not to get warnings when autogen.sh is called. Also changed
524        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
525    
526    44. To help people who use pcregrep to scan files containing exceedingly long
527        lines, the following changes have been made:
528    
529        (a) The default value of the buffer size parameter has been increased from
530            8K to 20K. (The actual buffer used is three times this size.)
531    
532        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
533            PCRE is built.
534    
535        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
536            to be set at run time.
537    
538        (d) Numerical values in pcregrep options can be followed by K or M, for
539            example --buffer-size=50K.
540    
541        (e) If a line being scanned overflows pcregrep's buffer, an error is now
542            given and the return code is set to 2.
543    
544    45. Add a pointer to the latest mark to the callout data block.
545    
546    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
547        partial match of an empty string instead of no match. This was specific to
548        the use of ".".
549    
550    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
551        complete match instead of a partial match. This bug was dependent on both
552        the PCRE_UTF8 and PCRE_DOTALL options being set.
553    
554    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
555        starting byte set, because \b was not being ignored.
556    
557    
558    Version 8.12 15-Jan-2011
559    ------------------------
560    
561    1.  Fixed some typos in the markup of the man pages, and wrote a script that
562        checks for such things as part of the documentation building process.
563    
564    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
565        --match-limit and --recursion-limit options (added for 8.11). In
566        particular, this made one of the standard tests fail. (The integer value
567        went into the wrong half of a long int.)
568    
569    3.  If the --colour option was given to pcregrep with -v (invert match), it
570        did strange things, either producing crazy output, or crashing. It should,
571        of course, ignore a request for colour when reporting lines that do not
572        match.
573    
574    4.  Another pcregrep bug caused similar problems if --colour was specified with
575        -M (multiline) and the pattern match finished with a line ending.
576    
577    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
578        matched in multiline mode, the following line was shown as part of the
579        match. This seems wrong, so I have changed it.
580    
581    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
582        the check for further matches in the same line (so they could be coloured)
583        to overrun the end of the current line. If another match was found, it was
584        incorrectly shown (and then shown again when found in the next line).
585    
586    7.  If pcregrep was compiled under Windows, there was a reference to the
587        function pcregrep_exit() before it was defined. I am assuming this was
588        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
589        reported by a user. I've moved the definition above the reference.
590    
591    
592    Version 8.11 10-Dec-2010
593    ------------------------
594    
595    1.  (*THEN) was not working properly if there were untried alternatives prior
596        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
597        backtracked to try for "b" instead of moving to the next alternative branch
598        at the same level (in this case, to look for "c"). The Perl documentation
599        is clear that when (*THEN) is backtracked onto, it goes to the "next
600        alternative in the innermost enclosing group".
601    
602    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
603        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
604        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
605        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
606        (*THEN).
607    
608    3.  If \s appeared in a character class, it removed the VT character from
609        the class, even if it had been included by some previous item, for example
610        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
611        of \s, but is part of the POSIX "space" class.)
612    
613    4.  A partial match never returns an empty string (because you can always
614        match an empty string at the end of the subject); however the checking for
615        an empty string was starting at the "start of match" point. This has been
616        changed to the "earliest inspected character" point, because the returned
617        data for a partial match starts at this character. This means that, for
618        example, /(?<=abc)def/ gives a partial match for the subject "abc"
619        (previously it gave "no match").
620    
621    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
622        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
623        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
624        has an implication that the given string is incomplete (because a partial
625        match is preferred over a full match). For this reason, these items now
626        give a partial match in this situation. [Aside: previously, the one case
627        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
628        match rather than a full match, which was wrong by the old rules, but is
629        now correct.]
630    
631    6.  There was a bug in the handling of #-introduced comments, recognized when
632        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
633        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
634        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
635        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
636        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
637        places in pcre_compile().
638    
639    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
640        comments when looking ahead for named forward references to subpatterns,
641        the only newline sequence it recognized was NL. It now handles newlines
642        according to the set newline convention.
643    
644    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
645        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
646        cater for a lack of strerror(). These oversights have been fixed.
647    
648    9.  Added --match-limit and --recursion-limit to pcregrep.
649    
650    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
651    
652    11. When the -o option was used, pcregrep was setting a return code of 1, even
653        when matches were found, and --line-buffered was not being honoured.
654    
655    12. Added an optional parentheses number to the -o and --only-matching options
656        of pcregrep.
657    
658    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
659        can match an empty string. The code to do it in pcretest and pcredemo
660        needed fixing:
661    
662        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
663            only one byte after an empty string match just before CRLF (this case
664            just got forgotten; "any" and "anycrlf" were OK).
665    
666        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
667            mode when an empty string match preceded an ASCII character followed by
668            a non-ASCII character. (The code for advancing by one character rather
669            than one byte was nonsense.)
670    
671        (c) The pcredemo.c sample program did not have any code at all to handle
672            the cases when CRLF is a valid newline sequence.
673    
674    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
675        as a starting offset was within the subject string. There is now a new
676        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
677        negative or greater than the length of the string. In order to test this,
678        pcretest is extended to allow the setting of negative starting offsets.
679    
680    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
681        starting offset points to the beginning of a UTF-8 character was
682        unnecessarily clumsy. I tidied it up.
683    
684    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
685        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
686    
687    17. Nobody had reported that the --include_dir option, which was added in
688        release 7.7 should have been called --include-dir (hyphen, not underscore)
689        for compatibility with GNU grep. I have changed it to --include-dir, but
690        left --include_dir as an undocumented synonym, and the same for
691        --exclude-dir, though that is not available in GNU grep, at least as of
692        release 2.5.4.
693    
694    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
695        characters from a string of bytes) have been redefined so as not to use
696        loops, in order to improve performance in some environments. At the same
697        time, I abstracted some of the common code into auxiliary macros to save
698        repetition (this should not affect the compiled code).
699    
700    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
701        compile-time error is now given if \c is not followed by an ASCII
702        character, that is, a byte less than 128. (In EBCDIC mode, the code is
703        different, and any byte value is allowed.)
704    
705    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
706        START_OPTIMIZE option, which is now allowed at compile time - but just
707        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
708        to pcregrep and other applications that have no direct access to PCRE
709        options. The new /Y option in pcretest sets this option when calling
710        pcre_compile().
711    
712    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
713        back references. Groups containing recursive back references were forced to
714        be atomic by that change, but in the case of named groups, the amount of
715        memory required was incorrectly computed, leading to "Failed: internal
716        error: code overflow". This has been fixed.
717    
718    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
719        pcretest.c, to avoid build problems in some Borland environments.
720    
721    
722    Version 8.10 25-Jun-2010
723    ------------------------
724    
725    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
726        THEN.
727    
728    2.  (*ACCEPT) was not working when inside an atomic group.
729    
730    3.  Inside a character class, \B is treated as a literal by default, but
731        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
732        causes the error). The code is unchanged, but I tidied the documentation.
733    
734    4.  Inside a character class, PCRE always treated \R and \X as literals,
735        whereas Perl faults them if its -w option is set. I have changed PCRE so
736        that it faults them when PCRE_EXTRA is set.
737    
738    5.  Added support for \N, which always matches any character other than
739        newline. (It is the same as "." when PCRE_DOTALL is not set.)
740    
741    6.  When compiling pcregrep with newer versions of gcc which may have
742        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
743        declared with attribute warn_unused_result" were given. Just casting the
744        result to (void) does not stop the warnings; a more elaborate fudge is
745        needed. I've used a macro to implement this.
746    
747    7.  Minor change to pcretest.c to avoid a compiler warning.
748    
749    8.  Added four artifical Unicode properties to help with an option to make
750        \s etc use properties (see next item). The new properties are: Xan
751        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
752    
753    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
754        use Unicode properties. (*UCP) at the start of a pattern can be used to set
755        this option. Modified pcretest to add /W to test this facility. Added
756        REG_UCP to make it available via the POSIX interface.
757    
758    10. Added --line-buffered to pcregrep.
759    
760    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
761        studied, and the match started with a letter with a code point greater than
762        127 whose first byte was different to the first byte of the other case of
763        the letter, the other case of this starting letter was not recognized
764        (#976).
765    
766    12. If a pattern that was studied started with a repeated Unicode property
767        test, for example, \p{Nd}+, there was the theoretical possibility of
768        setting up an incorrect bitmap of starting bytes, but fortunately it could
769        not have actually happened in practice until change 8 above was made (it
770        added property types that matched character-matching opcodes).
771    
772    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
773        possible starting bytes for non-anchored patterns.
774    
775    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
776        \R, and also a number of cases that involve Unicode properties, both
777        explicit and implicit when PCRE_UCP is set.
778    
779    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
780        input, it could crash or give wrong results if characters with values
781        greater than 0xc0 were present in the subject string. (Detail: it assumed
782        UTF-8 input when processing these items.)
783    
784    16. Added a lot of (int) casts to avoid compiler warnings in systems where
785        size_t is 64-bit (#991).
786    
787    17. Added a check for running out of memory when PCRE is compiled with
788        --disable-stack-for-recursion (#990).
789    
790    18. If the last data line in a file for pcretest does not have a newline on
791        the end, a newline was missing in the output.
792    
793    19. The default pcre_chartables.c file recognizes only ASCII characters (values
794        less than 128) in its various bitmaps. However, there is a facility for
795        generating tables according to the current locale when PCRE is compiled. It
796        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
797        characters, are recognized by isspace() and therefore were getting set in
798        these tables, and indeed these tables seem to approximate to ISO 8859. This
799        caused a problem in UTF-8 mode when pcre_study() was used to create a list
800        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
801        which of course cannot start UTF-8 characters. I have changed the code so
802        that only real ASCII characters (less than 128) and the correct starting
803        bytes for UTF-8 encodings are set for characters greater than 127 when in
804        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
805        altogether.)
806    
807    20. Added the /T option to pcretest so as to be able to run tests with non-
808        standard character tables, thus making it possible to include the tests
809        used for 19 above in the standard set of tests.
810    
811    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
812        reference to a subpattern the other side of a comment that contains an
813        opening parenthesis caused either an internal compiling error, or a
814        reference to the wrong subpattern.
815    
816    
817    Version 8.02 19-Mar-2010
818    ------------------------
819    
820    1.  The Unicode data tables have been updated to Unicode 5.2.0.
821    
822    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
823        configured.
824    
825    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
826        original author of that file, following a query about its status.
827    
828    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
829        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
830    
831    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
832        quantifier applied to a forward-referencing subroutine call, could compile
833        incorrect code or give the error "internal error: previously-checked
834        referenced subpattern not found".
835    
836    6.  Both MS Visual Studio and Symbian OS have problems with initializing
837        variables to point to external functions. For these systems, therefore,
838        pcre_malloc etc. are now initialized to local functions that call the
839        relevant global functions.
840    
841    7.  There were two entries missing in the vectors called coptable and poptable
842        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
843        I've fixed the data, and added a kludgy way of testing at compile time that
844        the lengths are correct (equal to the number of opcodes).
845    
846    8.  Following on from 7, I added a similar kludge to check the length of the
847        eint vector in pcreposix.c.
848    
849    9.  Error texts for pcre_compile() are held as one long string to avoid too
850        much relocation at load time. To find a text, the string is searched,
851        counting zeros. There was no check for running off the end of the string,
852        which could happen if a new error number was added without updating the
853        string.
854    
855    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
856    
857    11. \K was not working if it appeared in an atomic group or in a group that
858        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
859        \K is "not well defined" if used in an assertion. PCRE now accepts it if
860        the assertion is positive, but not if it is negative.
861    
862    12. Change 11 fortuitously reduced the size of the stack frame used in the
863        "match()" function of pcre_exec.c by one pointer. Forthcoming
864        implementation of support for (*MARK) will need an extra pointer on the
865        stack; I have reserved it now, so that the stack frame size does not
866        decrease.
867    
868    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
869        item in branch that calls a recursion is a subroutine call - as in the
870        second branch in the above example - was incorrectly given the compile-
871        time error "recursive call could loop indefinitely" because pcre_compile()
872        was not correctly checking the subroutine for matching a non-empty string.
873    
874    14. The checks for overrunning compiling workspace could trigger after an
875        overrun had occurred. This is a "should never occur" error, but it can be
876        triggered by pathological patterns such as hundreds of nested parentheses.
877        The checks now trigger 100 bytes before the end of the workspace.
878    
879    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
880    
881    
882    Version 8.01 19-Jan-2010
883    ------------------------
884    
885    1.  If a pattern contained a conditional subpattern with only one branch (in
886        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
887        computed the wrong minimum data length (which is of course zero for such
888        subpatterns). This could cause incorrect "no match" results.
889    
890    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
891        the pattern is reset in the first branch, pcre_compile() failed with
892        "internal error: code overflow at offset...". This happened only when
893        the reset was to the original external option setting. (An optimization
894        abstracts leading options settings into an external setting, which was the
895        cause of this.)
896    
897    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
898        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
899        assertion pattern did not match (meaning that the assertion was true), it
900        was incorrectly treated as false if the SKIP had been reached during the
901        matching. This also applied to assertions used as conditions.
902    
903    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
904        assertion subpattern, including such a pattern used as a condition,
905        unpredictable results occurred, instead of the error return
906        PCRE_ERROR_DFA_UITEM.
907    
908    5.  The C++ GlobalReplace function was not working like Perl for the special
909        situation when an empty string is matched. It now does the fancy magic
910        stuff that is necessary.
911    
912    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
913        removed. (These were left over from very, very early versions of PCRE.)
914    
915    7.  Some cosmetic changes to the code to make life easier when compiling it
916        as part of something else:
917    
918        (a) Change DEBUG to PCRE_DEBUG.
919    
920        (b) In pcre_compile(), rename the member of the "branch_chain" structure
921            called "current" as "current_branch", to prevent a collision with the
922            Linux macro when compiled as a kernel module.
923    
924        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
925            prevent a collision with the Linux macro when compiled as a kernel
926            module.
927    
928    8.  In pcre_compile() there are some checks for integer overflows that used to
929        cast potentially large values to (double). This has been changed to that
930        when building, a check for int64_t is made, and if it is found, it is used
931        instead, thus avoiding the use of floating point arithmetic. (There is no
932        other use of FP in PCRE.) If int64_t is not found, the fallback is to
933        double.
934    
935    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
936        2005 (difference between two addresses compared to an unsigned value).
937    
938    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
939        custom one, because of the following reported problem in Windows:
940    
941          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
942              under Win32.
943          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
944              therefore missing the function definition.
945          - The compiler thus generates a "C" signature for the test function.
946          - The linker fails to find the "C" function.
947          - PCRE fails to configure if asked to do so against libbz2.
948    
949    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
950        messages were output:
951    
952          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
953          rerunning libtoolize, to keep the correct libtool macros in-tree.
954          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
955    
956        I have done both of these things.
957    
958    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
959        most of the time, it *can* run out if it is given a pattern that contains a
960        runaway infinite recursion. I updated the discussion in the pcrestack man
961        page.
962    
963    13. Now that we have gone to the x.xx style of version numbers, the minor
964        version may start with zero. Using 08 or 09 is a bad idea because users
965        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
966        interpreted as invalid octal numbers. I've updated the previous comment in
967        configure.ac, and also added a check that gives an error if 08 or 09 are
968        used.
969    
970    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
971        causing partial matching to fail when the end of the subject matched \W
972        in a UTF-8 pattern where \W was quantified with a minimum of 3.
973    
974    15. There were some discrepancies between the declarations in pcre_internal.h
975        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
976        their definitions. The declarations used "const uschar *" and the
977        definitions used USPTR. Even though USPTR is normally defined as "const
978        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
979        reported that: "This difference in casting confuses some C++ compilers, for
980        example, SunCC recognizes above declarations as different functions and
981        generates broken code for hbpcre." I have changed the declarations to use
982        USPTR.
983    
984    16. GNU libtool is named differently on some systems. The autogen.sh script now
985        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
986        (FreeBSD).
987    
988    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
989        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
990        comment: "Figure out how to create a longlong from a string: strtoll and
991        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
992        instance, but it only takes 2 args instead of 3!"
993    
994    18. A subtle bug concerned with back references has been fixed by a change of
995        specification, with a corresponding code fix. A pattern such as
996        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
997        refers, was giving matches when it shouldn't. For example, xa=xaaa would
998        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
999        same bug. Such groups have to be quantified to be useful, or contained
1000        inside another quantified group. (If there's no repetition, the reference
1001        can never match.) The problem arises because, having left the group and
1002        moved on to the rest of the pattern, a later failure that backtracks into
1003        the group uses the captured value from the final iteration of the group
1004        rather than the correct earlier one. I have fixed this in PCRE by forcing
1005        any group that contains a reference to itself to be an atomic group; that
1006        is, there cannot be any backtracking into it once it has completed. This is
1007        similar to recursive and subroutine calls.
1008    
1009    
1010    Version 8.00 19-Oct-09
1011    ----------------------
1012    
1013    1.  The table for translating pcre_compile() error codes into POSIX error codes
1014        was out-of-date, and there was no check on the pcre_compile() error code
1015        being within the table. This could lead to an OK return being given in
1016        error.
1017    
1018    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1019        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1020        in a Windows environment.
1021    
1022    3.  The pcregrep --count option prints the count for each file even when it is
1023        zero, as does GNU grep. However, pcregrep was also printing all files when
1024        --files-with-matches was added. Now, when both options are given, it prints
1025        counts only for those files that have at least one match. (GNU grep just
1026        prints the file name in this circumstance, but including the count seems
1027        more useful - otherwise, why use --count?) Also ensured that the
1028        combination -clh just lists non-zero counts, with no names.
1029    
1030    4.  The long form of the pcregrep -F option was incorrectly implemented as
1031        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1032        but it seems right to fix it, and I didn't think it was worth preserving
1033        the old behaviour.
1034    
1035    5.  The command line items --regex=pattern and --regexp=pattern were not
1036        recognized by pcregrep, which required --regex pattern or --regexp pattern
1037        (with a space rather than an '='). The man page documented the '=' forms,
1038        which are compatible with GNU grep; these now work.
1039    
1040    6.  No libpcreposix.pc file was created for pkg-config; there was just
1041        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1042    
1043    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1044        when UCP support is not needed, by modifying the Python script that
1045        generates it from Unicode data files. This should not matter if the module
1046        is correctly used as a library, but I received one complaint about 50K of
1047        unwanted data. My guess is that the person linked everything into his
1048        program rather than using a library. Anyway, it does no harm.
1049    
1050    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1051        was a minimum greater than 1 for a wide character in a possessive
1052        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1053        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1054        character. Chaos in the form of incorrect output or a compiling loop could
1055        result.
1056    
1057    9.  The restrictions on what a pattern can contain when partial matching is
1058        requested for pcre_exec() have been removed. All patterns can now be
1059        partially matched by this function. In addition, if there are at least two
1060        slots in the offset vector, the offset of the earliest inspected character
1061        for the match and the offset of the end of the subject are set in them when
1062        PCRE_ERROR_PARTIAL is returned.
1063    
1064    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1065        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1066        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1067        and may be more useful for multi-segment matching.
1068    
1069    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1070        used to be given if ever the end of the subject was reached; now it is
1071        given only if matching could not proceed because another character was
1072        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1073        string "Z", which now yields "no match" instead of "partial match". In the
1074        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1075        final character ended with (*FAIL).
1076    
1077    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1078        if the pattern had a "must contain" character that was already found in the
1079        earlier partial match, unless partial matching was again requested. For
1080        example, with the pattern /dog.(body)?/, the "must contain" character is
1081        "g". If the first part-match was for the string "dog", restarting with
1082        "sbody" failed. This bug has been fixed.
1083    
1084    13. The string returned by pcre_dfa_exec() after a partial match has been
1085        changed so that it starts at the first inspected character rather than the
1086        first character of the match. This makes a difference only if the pattern
1087        starts with a lookbehind assertion or \b or \B (\K is not supported by
1088        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1089        matching functions compatible, and I think it's the right thing to do.
1090    
1091    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1092        so that the demonstration program is easily available in environments where
1093        PCRE has not been installed from source.
1094    
1095    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1096        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1097        library.
1098    
1099    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1100        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1101        is not the first non-POSIX option to be added. Clearly some people find
1102        these options useful.
1103    
1104    17. If a caller to the POSIX matching function regexec() passes a non-zero
1105        value for nmatch with a NULL value for pmatch, the value of
1106        nmatch is forced to zero.
1107    
1108    18. RunGrepTest did not have a test for the availability of the -u option of
1109        the diff command, as RunTest does. It now checks in the same way as
1110        RunTest, and also checks for the -b option.
1111    
1112    19. If an odd number of negated classes containing just a single character
1113        interposed, within parentheses, between a forward reference to a named
1114        subpattern and the definition of the subpattern, compilation crashed with
1115        an internal error, complaining that it could not find the referenced
1116        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1117        [The bug was that it was starting one character too far in when skipping
1118        over the character class, thus treating the ] as data rather than
1119        terminating the class. This meant it could skip too much.]
1120    
1121    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1122        /g option in pcretest when the pattern contains \K, which makes it possible
1123        to have an empty string match not at the start, even when the pattern is
1124        anchored. Updated pcretest and pcredemo to use this option.
1125    
1126    21. If the maximum number of capturing subpatterns in a recursion was greater
1127        than the maximum at the outer level, the higher number was returned, but
1128        with unset values at the outer level. The correct (outer level) value is
1129        now given.
1130    
1131    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1132        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1133        make it do so. The string so far is captured, making this feature
1134        compatible with Perl.
1135    
1136    23. The tests have been re-organized, adding tests 11 and 12, to make it
1137        possible to check the Perl 5.10 features against Perl 5.10.
1138    
1139    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1140        pattern matches a fixed length string. PCRE did not allow this; now it
1141        does. Neither allows recursion.
1142    
1143    25. I finally figured out how to implement a request to provide the minimum
1144        length of subject string that was needed in order to match a given pattern.
1145        (It was back references and recursion that I had previously got hung up
1146        on.) This code has now been added to pcre_study(); it finds a lower bound
1147        to the length of subject needed. It is not necessarily the greatest lower
1148        bound, but using it to avoid searching strings that are too short does give
1149        some useful speed-ups. The value is available to calling programs via
1150        pcre_fullinfo().
1151    
1152    26. While implementing 25, I discovered to my embarrassment that pcretest had
1153        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1154        study optimizations had never been tested with that matching function.
1155        Oops. What is worse, even when it was passed study data, there was a bug in
1156        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1157        were also very few tests of studied patterns with pcre_dfa_exec().
1158    
1159    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1160        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1161        on the other side of the coin, they are no longer allowed to have different
1162        names, because these cannot be distinguished in PCRE, and this has caused
1163        confusion. (This is a difference from Perl.)
1164    
1165    28. When duplicate subpattern names are present (necessarily with different
1166        numbers, as required by 27 above), and a test is made by name in a
1167        conditional pattern, either for a subpattern having been matched, or for
1168        recursion in such a pattern, all the associated numbered subpatterns are
1169        tested, and the overall condition is true if the condition is true for any
1170        one of them. This is the way Perl works, and is also more like the way
1171        testing by number works.
1172    
1173    
1174    Version 7.9 11-Apr-09
1175    ---------------------
1176    
1177    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1178        (pcretest), all targets were linked against these libraries. This included
1179        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1180        libraries. This caused unwanted dependencies to be created. This problem
1181        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1182        pcretest is linked with readline.
1183    
1184    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1185        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1186        moved outside it again, because FALSE and TRUE are already defined in AIX,
1187        but BOOL is not.
1188    
1189    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1190        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1191    
1192    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1193        hyphens) following file names and line numbers when outputting matching
1194        lines. This is not true; no spaces are inserted. I have also clarified the
1195        wording for the --colour (or --color) option.
1196    
1197    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1198        was not coloured; this is different to GNU grep, so I have changed it to be
1199        the same.
1200    
1201    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1202        each matching line was coloured. Now it goes on to look for further matches
1203        of any of the test patterns, which is the same behaviour as GNU grep.
1204    
1205    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1206        doesn't make sense to accept an empty string match in pcregrep, so I have
1207        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1208        seems to be how GNU grep behaves.
1209    
1210    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1211        start or after a newline", because the conditional assertion was not being
1212        correctly handled. The rule now is that both the assertion and what follows
1213        in the first alternative must satisfy the test.
1214    
1215    9.  If auto-callout was enabled in a pattern with a conditional group whose
1216        condition was an assertion, PCRE could crash during matching, both with
1217        pcre_exec() and pcre_dfa_exec().
1218    
1219    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1220        used for matching.
1221    
1222    11. Unicode property support in character classes was not working for
1223        characters (bytes) greater than 127 when not in UTF-8 mode.
1224    
1225    12. Added the -M command line option to pcretest.
1226    
1227    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1228    
1229    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1230    
1231    16. Added comments and documentation about mis-use of no_arg in the C++
1232        wrapper.
1233    
1234    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1235        from Martin Jerabek that uses macro names for all relevant character and
1236        string constants.
1237    
1238    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1239        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1240        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1241        these, but not everybody uses configure.
1242    
1243    19. A conditional group that had only one branch was not being correctly
1244        recognized as an item that could match an empty string. This meant that an
1245        enclosing group might also not be so recognized, causing infinite looping
1246        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1247        with the subject "ab", where knowledge that the repeated group can match
1248        nothing is needed in order to break the loop.
1249    
1250    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1251        exec(), but without supplying a callout function, matching went wrong.
1252    
1253    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1254        leak if the size of the offset vector was greater than 30. When the vector
1255        is smaller, the saved offsets during recursion go onto a local stack
1256        vector, but for larger vectors malloc() is used. It was failing to free
1257        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1258        error, in fact).
1259    
1260    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1261        heapframe that is used only when UTF-8 support is enabled. This caused no
1262        problem, but was untidy.
1263    
1264    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1265        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1266        included within another project.
1267    
1268    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1269        slightly modified by me:
1270    
1271          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1272              not building pcregrep.
1273    
1274          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1275              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1276    
1277    25. Forward references, both numeric and by name, in patterns that made use of
1278        duplicate group numbers, could behave incorrectly or give incorrect errors,
1279        because when scanning forward to find the reference group, PCRE was not
1280        taking into account the duplicate group numbers. A pattern such as
1281        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1282    
1283    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1284        the feature of a custom pointer more persuasive (as requested by a user).
1285    
1286    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1287        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1288        pre-defined.
1289    
1290    28. Added support for (*UTF8) at the start of a pattern.
1291    
1292    29. Arrange for flags added by the "release type" setting in CMake to be shown
1293        in the configuration summary.
1294    
1295    
1296    Version 7.8 05-Sep-08
1297    ---------------------
1298    
1299    1.  Replaced UCP searching code with optimized version as implemented for Ad
1300        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1301        stage table and inline lookup instead of a function, giving speed ups of 2
1302        to 5 times on some simple patterns that I tested. Permission was given to
1303        distribute the MultiStage2.py script that generates the tables (it's not in
1304        the tarball, but is in the Subversion repository).
1305    
1306    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1307        scripts.
1308    
1309    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1310        a group with a zero qualifier. The result of the study could be incorrect,
1311        or the function might crash, depending on the pattern.
1312    
1313    4.  Caseless matching was not working for non-ASCII characters in back
1314        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1315        It now works when Unicode Property Support is available.
1316    
1317    5.  In pcretest, an escape such as \x{de} in the data was always generating
1318        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1319        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1320        truncation.
1321    
1322    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1323    
1324    7.  Added two (int) casts to pcregrep when printing the difference of two
1325        pointers, in case they are 64-bit values.
1326    
1327    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1328        test 2 if it fails.
1329    
1330    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1331        and a #define of that name to empty if it is not externally set. This is to
1332        allow users of MSVC to set it if necessary.
1333    
1334    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1335        the convenience functions in the pcre_get.c source file.
1336    
1337    11. An option change at the start of a pattern that had top-level alternatives
1338        could cause overwriting and/or a crash. This command provoked a crash in
1339        some environments:
1340    
1341          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1342    
1343        This potential security problem was recorded as CVE-2008-2371.
1344    
1345    12. For a pattern where the match had to start at the beginning or immediately
1346        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1347        pcre_dfa_exec() could read past the end of the passed subject if there was
1348        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1349        pcretest so that it places the subject at the end of its malloc-ed buffer.
1350    
1351    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1352        exec() might read past the end of the data buffer in UTF-8 mode.
1353    
1354    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1355        the data contained the byte 0x85 as part of a UTF-8 character within its
1356        first line. This applied both to normal and DFA matching.
1357    
1358    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1359        /^[^d]*?$/8 failed to match "abc".
1360    
1361    16. Added a missing copyright notice to pcrecpp_internal.h.
1362    
1363    17. Make it more clear in the documentation that values returned from
1364        pcre_exec() in ovector are byte offsets, not character counts.
1365    
1366    18. Tidied a few places to stop certain compilers from issuing warnings.
1367    
1368    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1369        supplied by Stefan Weber. I made a further small update for 7.8 because
1370        there is a change of source arrangements: the pcre_searchfuncs.c module is
1371        replaced by pcre_ucd.c.
1372    
1373    
1374    Version 7.7 07-May-08
1375    ---------------------
1376    
1377    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1378        a string to a long long, pretend we don't even have a long long." This is
1379        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1380    
1381    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1382        pre-7.6 versions, which defined a global no_arg variable instead of putting
1383        it in the RE class. (See also #8 below.)
1384    
1385    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1386        Lopes.
1387    
1388    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1389    
1390        (1) The include/exclude patterns were being applied to the whole pathnames
1391            of files, instead of just to the final components.
1392    
1393        (2) If there was more than one level of directory, the subdirectories were
1394            skipped unless they satisfied the include/exclude conditions. This is
1395            inconsistent with GNU grep (and could even be seen as contrary to the
1396            pcregrep specification - which I improved to make it absolutely clear).
1397            The action now is always to scan all levels of directory, and just
1398            apply the include/exclude patterns to regular files.
1399    
1400    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1401        --exclude_dir in the tests to avoid scanning .svn directories.
1402    
1403    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1404        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1405        doesn't support NULs in patterns.
1406    
1407    7.  Added some missing "const"s to declarations of static tables in
1408        pcre_compile.c and pcre_dfa_exec.c.
1409    
1410    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1411        caused by fix #2  above. (Subsequently also a second patch to fix the
1412        first patch. And a third patch - this was a messy problem.)
1413    
1414    9.  Applied Craig's patch to remove the use of push_back().
1415    
1416    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1417        matching function regexec().
1418    
1419    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1420        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1421        references. PCRE supports relative numbers with this syntax (I don't think
1422        Oniguruma does).
1423    
1424    12. Previously, a group with a zero repeat such as (...){0} was completely
1425        omitted from the compiled regex. However, this means that if the group
1426        was called as a subroutine from elsewhere in the pattern, things went wrong
1427        (an internal error was given). Such groups are now left in the compiled
1428        pattern, with a new opcode that causes them to be skipped at execution
1429        time.
1430    
1431    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1432        to the way PCRE behaves:
1433    
1434        (a) A lone ] character is dis-allowed (Perl treats it as data).
1435    
1436        (b) A back reference to an unmatched subpattern matches an empty string
1437            (Perl fails the current match path).
1438    
1439        (c) A data ] in a character class must be notated as \] because if the
1440            first data character in a class is ], it defines an empty class. (In
1441            Perl it is not possible to have an empty class.) The empty class []
1442            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1443            The negative empty class [^] matches any one character, independently
1444            of the DOTALL setting.
1445    
1446    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1447        non-existent subpattern following a character class starting with ']' and
1448        containing () gave an internal compiling error instead of "reference to
1449        non-existent subpattern". Fortunately, when the pattern did exist, the
1450        compiled code was correct. (When scanning forwards to check for the
1451        existencd of the subpattern, it was treating the data ']' as terminating
1452        the class, so got the count wrong. When actually compiling, the reference
1453        was subsequently set up correctly.)
1454    
1455    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1456        it was being rejected as not supported by pcre_dfa_exec(), even though
1457        other assertions are supported. I have made pcre_dfa_exec() support
1458        (*FAIL).
1459    
1460    16. The implementation of 13c above involved the invention of a new opcode,
1461        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1462        cannot be changed at match time, I realized I could make a small
1463        improvement to matching performance by compiling OP_ALLANY instead of
1464        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1465        on the OP_ANY path.
1466    
1467    17. Compiling pcretest on Windows with readline support failed without the
1468        following two fixes: (1) Make the unistd.h include conditional on
1469        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1470    
1471    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1472        ncurses library to be included for pcretest when ReadLine support is
1473        requested, but also to allow for it to be overridden. This patch came from
1474        Daniel Bergström.
1475    
1476    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1477        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1478        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1479        spotting this.
1480    
1481    
1482    Version 7.6 28-Jan-08
1483    ---------------------
1484    
1485    1.  A character class containing a very large number of characters with
1486        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1487        overflow.
1488    
1489    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1490        HAVE_LONG_LONG is not defined.
1491    
1492    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1493        bring them up to date and include new features. This patch includes:
1494    
1495        - Fixed PH's badly added libz and libbz2 support.
1496        - Fixed a problem with static linking.
1497        - Added pcredemo. [But later removed - see 7 below.]
1498        - Fixed dftables problem and added an option.
1499        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1500            HAVE_LONG_LONG.
1501        - Added readline support for pcretest.
1502        - Added an listing of the option settings after cmake has run.
1503    
1504    4.  A user submitted a patch to Makefile that makes it easy to create
1505        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1506        Makefile.am that cause it to include this special target, without
1507        affecting anything else. Note that the same mingw target plus all
1508        the other distribution libraries and programs are now supported
1509        when configuring with CMake (see 6 below) instead of with
1510        Configure/Make.
1511    
1512    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1513        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1514        exported in the Windows port". It has not yet been confirmed that the patch
1515        solves the problem, but it does no harm.
1516    
1517    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1518        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1519        with CMake, and also correct the comment about stack recursion.
1520    
1521    7.  Remove the automatic building of pcredemo from the ./configure system and
1522        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1523        of a program that users should build themselves after PCRE is installed, so
1524        building it automatically is not really right. What is more, it gave
1525        trouble in some build environments.
1526    
1527    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1528    
1529    
1530    Version 7.5 10-Jan-08
1531    ---------------------
1532    
1533    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1534        values in parens when parsing an RE using the C++ wrapper."
1535    
1536    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1537        Characters greater than 255 were excluded from the class instead of being
1538        included.
1539    
1540    3.  The same bug as (2) above applied to negated POSIX classes such as
1541        [:^space:].
1542    
1543    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1544        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1545        I have changed it.
1546    
1547    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1548        first named subpattern) and a construct such as (?&a) would reference the
1549        first named subpattern whose name started with "a" (in other words, the
1550        length check was missing). Both these problems are fixed. "Subpattern name
1551        expected" is now given for (?&) (a zero-length name), and this patch also
1552        makes it give the same error for \k'' (previously it complained that that
1553        was a reference to a non-existent subpattern).
1554    
1555    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1556        this is right because (?- can be followed by option settings as well as by
1557        digits. I have, however, made the messages clearer.
1558    
1559    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1560        than the number used in the conditional) now cause a compile-time error.
1561        This is actually not compatible with Perl, which accepts such patterns, but
1562        treats the conditional as always being FALSE (as PCRE used to), but it
1563        seems to me that giving a diagnostic is better.
1564    
1565    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1566        and messages.
1567    
1568    9.  Fix two occurrences of "backslash" in comments that should have been
1569        "backspace".
1570    
1571    10. Remove two redundant lines of code that can never be obeyed (their function
1572        was moved elsewhere).
1573    
1574    11. The program that makes PCRE's Unicode character property table had a bug
1575        which caused it to generate incorrect table entries for sequences of
1576        characters that have the same character type, but are in different scripts.
1577        It amalgamated them into a single range, with the script of the first of
1578        them. In other words, some characters were in the wrong script. There were
1579        thirteen such cases, affecting characters in the following ranges:
1580    
1581          U+002b0 - U+002c1
1582          U+0060c - U+0060d
1583          U+0061e - U+00612
1584          U+0064b - U+0065e
1585          U+0074d - U+0076d
1586          U+01800 - U+01805
1587          U+01d00 - U+01d77
1588          U+01d9b - U+01dbf
1589          U+0200b - U+0200f
1590          U+030fc - U+030fe
1591          U+03260 - U+0327f
1592          U+0fb46 - U+0fbb1
1593          U+10450 - U+1049d
1594    
1595    12. The -o option (show only the matching part of a line) for pcregrep was not
1596        compatible with GNU grep in that, if there was more than one match in a
1597        line, it showed only the first of them. It now behaves in the same way as
1598        GNU grep.
1599    
1600    13. If the -o and -v options were combined for pcregrep, it printed a blank
1601        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1602        does the same. The return code can be used to tell if there were any
1603        non-matching lines.
1604    
1605    14. Added --file-offsets and --line-offsets to pcregrep.
1606    
1607    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1608        infinitely looping recursion. The bug was that positive lookaheads were not
1609        being skipped when checking for a possible empty match (negative lookaheads
1610        and both kinds of lookbehind were skipped).
1611    
1612    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1613        inclusion of <windows.h> to before rather than after the definition of
1614        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1615    
1616    17. Specifying a possessive quantifier with a specific limit for a Unicode
1617        character property caused pcre_compile() to compile bad code, which led at
1618        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1619        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1620        caused the error; without that there was no problem.
1621    
1622    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1623    
1624    19. Added --enable-pcretest-libreadline.
1625    
1626    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1627        RE::GlobalReplace(). As a result, the number of replacements returned was
1628        double what it should be. I removed one of the increments, but Craig sent a
1629        later patch that removed the other one (the right fix) and added unit tests
1630        that check the return values (which was not done before).
1631    
1632    21. Several CMake things:
1633    
1634        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1635            the names libpcre and libpcreposix, not just pcre and pcreposix.
1636    
1637        (2) The above change means that pcretest and pcregrep are now correctly
1638            linked with the newly-built libraries, not previously installed ones.
1639    
1640        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1641    
1642    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1643        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1644        UTF-8 newline character). The key issue is that the pattern starts .*;
1645        this means that the match must be either at the beginning, or after a
1646        newline. The bug was in the code for advancing after a failed match and
1647        checking that the new position followed a newline. It was not taking
1648        account of UTF-8 characters correctly.
1649    
1650    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1651        character classes. PCRE was not treating the sequence [:...:] as a
1652        character class unless the ... were all letters. Perl, however, seems to
1653        allow any characters between [: and :], though of course it rejects as
1654        unknown any "names" that contain non-letters, because all the known class
1655        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1656        for example, whereas PCRE did not - it did not recognize a POSIX character
1657        class. This seemed a bit dangerous, so the code has been changed to be
1658        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1659        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1660        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1661        Perl does, and where it didn't before.
1662    
1663    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1664        Windows environments %n is disabled by default.
1665    
1666    
1667    Version 7.4 21-Sep-07
1668    ---------------------
1669    
1670    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1671        means that a class such as [\s] counted as "explicit reference to CR or
1672        LF". That isn't really right - the whole point of the change was to try to
1673        help when there was an actual mention of one of the two characters. So now
1674        the change happens only if \r or \n (or a literal CR or LF) character is
1675        encountered.
1676    
1677    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1678        of both had grown to the point where there were only 3 bits left.
1679        Fortunately, there was spare space in the data structure, and so I have
1680        moved the internal flags into a new 16-bit field to free up more option
1681        bits.
1682    
1683    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1684        but did not set the internal JCHANGED flag - either of these is enough to
1685        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1686        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1687        start sets both bits.
1688    
1689    4.  Added options (at build time, compile time, exec time) to change \R from
1690        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1691    
1692    5.  doc/pcresyntax.html was missing from the distribution.
1693    
1694    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1695        compatibility, even though it is no longer used.
1696    
1697    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1698        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1699        windows.h file is present (where different names are used). [This was
1700        reversed later after testing - see 16 below.]
1701    
1702    8.  Changed all #include <config.h> to #include "config.h". There were also
1703        some further <pcre.h> cases that I changed to "pcre.h".
1704    
1705    9.  When pcregrep was used with the --colour option, it missed the line ending
1706        sequence off the lines that it output.
1707    
1708    10. It was pointed out to me that arrays of string pointers cause lots of
1709        relocations when a shared library is dynamically loaded. A technique of
1710        using a single long string with a table of offsets can drastically reduce
1711        these. I have refactored PCRE in four places to do this. The result is
1712        dramatic:
1713    
1714          Originally:                          290
1715          After changing UCP table:            187
1716          After changing error message table:   43
1717          After changing table of "verbs"       36
1718          After changing table of Posix names   22
1719    
1720        Thanks to the folks working on Gregex for glib for this insight.
1721    
1722    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1723        unicode-properties was also set.
1724    
1725    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1726    
1727    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1728        checked only for CRLF.
1729    
1730    14. Added casts to pcretest.c to avoid compiler warnings.
1731    
1732    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1733    
1734    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1735        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1736        entirely. This removes changes made in 7 above.
1737    
1738    17. The CMake files have been updated, and there is now more information about
1739        building with CMake in the NON-UNIX-USE document.
1740    
1741    
1742    Version 7.3 28-Aug-07
1743    ---------------------
1744    
1745     1. In the rejigging of the build system that eventually resulted in 7.1, the
1746        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1747        brackets there is not right, since it causes compilers to look for an
1748        installed pcre.h, not the version that is in the source that is being
1749        compiled (which of course may be different). I have changed it back to:
1750    
1751          #include "pcre.h"
1752    
1753        I have a vague recollection that the change was concerned with compiling in
1754        different directories, but in the new build system, that is taken care of
1755        by the VPATH setting the Makefile.
1756    
1757     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1758        when the subject happened to end in the byte 0x85 (e.g. if the last
1759        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1760        characters but of course it shouldn't be taken as a newline when it is part
1761        of another character. The bug was that, for an unlimited repeat of . in
1762        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1763        characters when looking for a newline.
1764    
1765     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1766    
1767     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1768        in debug output.
1769    
1770     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1771        long printing in the pcrecpp unittest when running under MinGW.
1772    
1773     6. ESC_K was left out of the EBCDIC table.
1774    
1775     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1776        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1777        limit also applies to "virtual nesting" when a pattern is recursive, and in
1778        this case 1000 isn't so big. I have been able to remove this limit at the
1779        expense of backing off one optimization in certain circumstances. Normally,
1780        when pcre_exec() would call its internal match() function recursively and
1781        immediately return the result unconditionally, it uses a "tail recursion"
1782        feature to save stack. However, when a subpattern that can match an empty
1783        string has an unlimited repetition quantifier, it no longer makes this
1784        optimization. That gives it a stack frame in which to save the data for
1785        checking that an empty string has been matched. Previously this was taken
1786        from the 1000-entry workspace that had been reserved. So now there is no
1787        explicit limit, but more stack is used.
1788    
1789     8. Applied Daniel's patches to solve problems with the import/export magic
1790        syntax that is required for Windows, and which was going wrong for the
1791        pcreposix and pcrecpp parts of the library. These were overlooked when this
1792        problem was solved for the main library.
1793    
1794     9. There were some crude static tests to avoid integer overflow when computing
1795        the size of patterns that contain repeated groups with explicit upper
1796        limits. As the maximum quantifier is 65535, the maximum group length was
1797        set at 30,000 so that the product of these two numbers did not overflow a
1798        32-bit integer. However, it turns out that people want to use groups that
1799        are longer than 30,000 bytes (though not repeat them that many times).
1800        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1801        made it possible to implement the integer overflow checks in a much more
1802        dynamic way, which I have now done. The artificial limitation on group
1803        length has been removed - we now have only the limit on the total length of
1804        the compiled pattern, which depends on the LINK_SIZE setting.
1805    
1806    10. Fixed a bug in the documentation for get/copy named substring when
1807        duplicate names are permitted. If none of the named substrings are set, the
1808        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1809        empty string.
1810    
1811    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1812        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1813        because the ] is interpreted as the first data character and the
1814        terminating ] is not found. PCRE has been made compatible with Perl in this
1815        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1816        cause memory overwriting.
1817    
1818    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1819        string has been matched (to stop an infinite loop). It was not recognizing
1820        a conditional subpattern that could match an empty string if that
1821        subpattern was within another subpattern. For example, it looped when
1822        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1823        condition was not nested. This bug has been fixed.
1824    
1825    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1826        past the start of the subject in the presence of bytes with the top bit
1827        set, for example "\x8aBCD".
1828    
1829    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1830        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1831    
1832    14. Optimized (?!) to (*FAIL).
1833    
1834    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1835        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1836        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1837        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1838        does: it's just the validity check that is more restrictive.
1839    
1840    16. Inserted checks for integer overflows during escape sequence (backslash)
1841        processing, and also fixed erroneous offset values for syntax errors during
1842        backslash processing.
1843    
1844    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1845        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1846    
1847    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1848        caused an overrun.
1849    
1850    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1851        something other than just ASCII characters) inside a group that had an
1852        unlimited repeat caused a loop at compile time (while checking to see
1853        whether the group could match an empty string).
1854    
1855    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1856        [\P{Any}] did so. (Error in the code for printing property names.)
1857    
1858    21. An orphan \E inside a character class could cause a crash.
1859    
1860    22. A repeated capturing bracket such as (A)? could cause a wild memory
1861        reference during compilation.
1862    
1863    23. There are several functions in pcre_compile() that scan along a compiled
1864        expression for various reasons (e.g. to see if it's fixed length for look
1865        behind). There were bugs in these functions when a repeated \p or \P was
1866        present in the pattern. These operators have additional parameters compared
1867        with \d, etc, and these were not being taken into account when moving along
1868        the compiled data. Specifically:
1869    
1870        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1871            length.
1872    
1873        (b) An item such as \pL+ within a repeated group could cause crashes or
1874            loops.
1875    
1876        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1877            "reference to non-existent subpattern" error.
1878    
1879        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1880    
1881    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1882        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1883    
1884    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1885    
1886    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1887        character were causing crashes (broken optimization).
1888    
1889    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1890        \p or \P) caused a compile-time loop.
1891    
1892    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1893        break. For example, the unstudied pattern [\r\n]A does not match the string
1894        "\r\nA" because change 7.0/46 below moves the current point on by two
1895        characters after failing to match at the start. However, the pattern \nA
1896        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1897        the same is true. There doesn't seem any very clean way out of this, but
1898        what I have chosen to do makes the common cases work: PCRE now takes note
1899        of whether there can be an explicit match for \r or \n anywhere in the
1900        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1901        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1902        pattern has explicit CR or LF references.
1903    
1904    29. Added (*CR) etc for changing newline setting at start of pattern.
1905    
1906    
1907    Version 7.2 19-Jun-07
1908    ---------------------
1909    
1910     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1911        which is apparently normally available under Windows.
1912    
1913     2. Re-jig the pcregrep tests with different newline settings in an attempt
1914        to make them independent of the local environment's newline setting.
1915    
1916     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1917    
1918     4. Some of the "internals" tests were previously cut out when the link size
1919        was not 2, because the output contained actual offsets. The recent new
1920        "Z" feature of pcretest means that these can be cut out, making the tests
1921        usable with all link sizes.
1922    
1923     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1924        stack recursion. This gives a massive performance boost under BSD, but just
1925        a small improvement under Linux. However, it saves one field in the frame
1926        in all cases.
1927    
1928     6. Added more features from the forthcoming Perl 5.10:
1929    
1930        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1931            recursion call. It refers to the nth most recently opened parentheses.
1932    
1933        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1934            to be opened parentheses.
1935    
1936        (c) Conditions that refer to capturing parentheses can be specified
1937            relatively, for example, (?(-2)... or (?(+3)...
1938    
1939        (d) \K resets the start of the current match so that everything before
1940            is not part of it.
1941    
1942        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1943    
1944        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1945            reference syntax.
1946    
1947        (g) (?| introduces a group in which the numbering of parentheses in each
1948            alternative starts with the same number.
1949    
1950        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1951    
1952     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1953        PCRE_INFO_JCHANGED.
1954    
1955     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1956        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1957        for detecting groups that can match an empty string.
1958    
1959     9. A pattern with a very large number of alternatives (more than several
1960        hundred) was running out of internal workspace during the pre-compile
1961        phase, where pcre_compile() figures out how much memory will be needed. A
1962        bit of new cunning has reduced the workspace needed for groups with
1963        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1964        workspace instead of running out of the 4096 that are available.
1965    
1966    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1967    
1968    11. Applied patch from Google to remove an optimization that didn't quite work.
1969        The report of the bug said:
1970    
1971          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1972          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1973          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1974    
1975    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1976        it matched the wrong number of bytes.
1977    
1978    
1979    Version 7.1 24-Apr-07
1980  ---------------------  ---------------------
1981    
1982   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
# Line 135  Version 7.1 12-Mar-07 Line 2110  Version 7.1 12-Mar-07
2110      was because its rules for how to advance for /g after matching an empty      was because its rules for how to advance for /g after matching an empty
2111      string at the end of a line did not allow for this case. They now check for      string at the end of a line did not allow for this case. They now check for
2112      it specially.      it specially.
2113    
2114  20. pcretest is supposed to handle patterns and data of any length, by  20. pcretest is supposed to handle patterns and data of any length, by
2115      extending its buffers when necessary. It was getting this wrong when the      extending its buffers when necessary. It was getting this wrong when the
2116      buffer for a data line had to be extended.      buffer for a data line had to be extended.
2117    
2118  21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or  21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2119      CRLF as a newline sequence.      CRLF as a newline sequence.
2120    
2121    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2122        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2123        I have nevertheless tidied it up.
2124    
2125    23. Added some casts to kill warnings from HP-UX ia64 compiler.
2126    
2127    24. Added a man page for pcre-config.
2128    
2129    
2130  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06

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