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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14    
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
23    
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
28    
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
34    
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
38    
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
46    
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
72    
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
77    
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collection of tests with study enabled,
83        and thereby test pcre_study() more easily.
84    
85    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
86        restoration of the capturing data to the outer values was not happening
87        correctly.
88    
89    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
90        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
91        pattern had matched an empty string, and so incorrectly returned a no
92        match.
93    
94    17. There was optimizing code for the last branch of non-capturing parentheses,
95        and also for the obeyed branch of a conditional subexpression, which used
96        tail recursion to cut down on stack usage. Unfortunately, not that there is
97        the possibility of (*THEN) occurring in these branches, tail recursion is
98        no longer possible because the return has to be checked for (*THEN). These
99        two optimizations have therefore been removed.
100    
101    
102    Version 8.12 15-Jan-2011
103    ------------------------
104    
105    1.  Fixed some typos in the markup of the man pages, and wrote a script that
106        checks for such things as part of the documentation building process.
107    
108    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
109        --match-limit and --recursion-limit options (added for 8.11). In
110        particular, this made one of the standard tests fail. (The integer value
111        went into the wrong half of a long int.)
112    
113    3.  If the --colour option was given to pcregrep with -v (invert match), it
114        did strange things, either producing crazy output, or crashing. It should,
115        of course, ignore a request for colour when reporting lines that do not
116        match.
117    
118    4.  Another pcregrep bug caused similar problems if --colour was specified with
119        -M (multiline) and the pattern match finished with a line ending.
120    
121    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
122        matched in multiline mode, the following line was shown as part of the
123        match. This seems wrong, so I have changed it.
124    
125    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
126        the check for further matches in the same line (so they could be coloured)
127        to overrun the end of the current line. If another match was found, it was
128        incorrectly shown (and then shown again when found in the next line).
129    
130    7.  If pcregrep was compiled under Windows, there was a reference to the
131        function pcregrep_exit() before it was defined. I am assuming this was
132        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
133        reported by a user. I've moved the definition above the reference.
134    
135    
136    Version 8.11 10-Dec-2010
137    ------------------------
138    
139    1.  (*THEN) was not working properly if there were untried alternatives prior
140        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
141        backtracked to try for "b" instead of moving to the next alternative branch
142        at the same level (in this case, to look for "c"). The Perl documentation
143        is clear that when (*THEN) is backtracked onto, it goes to the "next
144        alternative in the innermost enclosing group".
145    
146    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
147        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
148        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
149        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
150        (*THEN).
151    
152    3.  If \s appeared in a character class, it removed the VT character from
153        the class, even if it had been included by some previous item, for example
154        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
155        of \s, but is part of the POSIX "space" class.)
156    
157    4.  A partial match never returns an empty string (because you can always
158        match an empty string at the end of the subject); however the checking for
159        an empty string was starting at the "start of match" point. This has been
160        changed to the "earliest inspected character" point, because the returned
161        data for a partial match starts at this character. This means that, for
162        example, /(?<=abc)def/ gives a partial match for the subject "abc"
163        (previously it gave "no match").
164    
165    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
166        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
167        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
168        has an implication that the given string is incomplete (because a partial
169        match is preferred over a full match). For this reason, these items now
170        give a partial match in this situation. [Aside: previously, the one case
171        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
172        match rather than a full match, which was wrong by the old rules, but is
173        now correct.]
174    
175    6.  There was a bug in the handling of #-introduced comments, recognized when
176        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
177        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
178        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
179        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
180        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
181        places in pcre_compile().
182    
183    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
184        comments when looking ahead for named forward references to subpatterns,
185        the only newline sequence it recognized was NL. It now handles newlines
186        according to the set newline convention.
187    
188    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
189        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
190        cater for a lack of strerror(). These oversights have been fixed.
191    
192    9.  Added --match-limit and --recursion-limit to pcregrep.
193    
194    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
195    
196    11. When the -o option was used, pcregrep was setting a return code of 1, even
197        when matches were found, and --line-buffered was not being honoured.
198    
199    12. Added an optional parentheses number to the -o and --only-matching options
200        of pcregrep.
201    
202    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
203        can match an empty string. The code to do it in pcretest and pcredemo
204        needed fixing:
205    
206        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
207            only one byte after an empty string match just before CRLF (this case
208            just got forgotten; "any" and "anycrlf" were OK).
209    
210        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
211            mode when an empty string match preceded an ASCII character followed by
212            a non-ASCII character. (The code for advancing by one character rather
213            than one byte was nonsense.)
214    
215        (c) The pcredemo.c sample program did not have any code at all to handle
216            the cases when CRLF is a valid newline sequence.
217    
218    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
219        as a starting offset was within the subject string. There is now a new
220        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
221        negative or greater than the length of the string. In order to test this,
222        pcretest is extended to allow the setting of negative starting offsets.
223    
224    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
225        starting offset points to the beginning of a UTF-8 character was
226        unnecessarily clumsy. I tidied it up.
227    
228    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
229        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
230    
231    17. Nobody had reported that the --include_dir option, which was added in
232        release 7.7 should have been called --include-dir (hyphen, not underscore)
233        for compatibility with GNU grep. I have changed it to --include-dir, but
234        left --include_dir as an undocumented synonym, and the same for
235        --exclude-dir, though that is not available in GNU grep, at least as of
236        release 2.5.4.
237    
238    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
239        characters from a string of bytes) have been redefined so as not to use
240        loops, in order to improve performance in some environments. At the same
241        time, I abstracted some of the common code into auxiliary macros to save
242        repetition (this should not affect the compiled code).
243    
244    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
245        compile-time error is now given if \c is not followed by an ASCII
246        character, that is, a byte less than 128. (In EBCDIC mode, the code is
247        different, and any byte value is allowed.)
248    
249    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
250        START_OPTIMIZE option, which is now allowed at compile time - but just
251        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
252        to pcregrep and other applications that have no direct access to PCRE
253        options. The new /Y option in pcretest sets this option when calling
254        pcre_compile().
255    
256    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
257        back references. Groups containing recursive back references were forced to
258        be atomic by that change, but in the case of named groups, the amount of
259        memory required was incorrectly computed, leading to "Failed: internal
260        error: code overflow". This has been fixed.
261    
262    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
263        pcretest.c, to avoid build problems in some Borland environments.
264    
265    
266    Version 8.10 25-Jun-2010
267    ------------------------
268    
269    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
270        THEN.
271    
272    2.  (*ACCEPT) was not working when inside an atomic group.
273    
274    3.  Inside a character class, \B is treated as a literal by default, but
275        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
276        causes the error). The code is unchanged, but I tidied the documentation.
277    
278    4.  Inside a character class, PCRE always treated \R and \X as literals,
279        whereas Perl faults them if its -w option is set. I have changed PCRE so
280        that it faults them when PCRE_EXTRA is set.
281    
282    5.  Added support for \N, which always matches any character other than
283        newline. (It is the same as "." when PCRE_DOTALL is not set.)
284    
285    6.  When compiling pcregrep with newer versions of gcc which may have
286        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
287        declared with attribute warn_unused_result" were given. Just casting the
288        result to (void) does not stop the warnings; a more elaborate fudge is
289        needed. I've used a macro to implement this.
290    
291    7.  Minor change to pcretest.c to avoid a compiler warning.
292    
293    8.  Added four artifical Unicode properties to help with an option to make
294        \s etc use properties (see next item). The new properties are: Xan
295        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
296    
297    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
298        use Unicode properties. (*UCP) at the start of a pattern can be used to set
299        this option. Modified pcretest to add /W to test this facility. Added
300        REG_UCP to make it available via the POSIX interface.
301    
302    10. Added --line-buffered to pcregrep.
303    
304    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
305        studied, and the match started with a letter with a code point greater than
306        127 whose first byte was different to the first byte of the other case of
307        the letter, the other case of this starting letter was not recognized
308        (#976).
309    
310    12. If a pattern that was studied started with a repeated Unicode property
311        test, for example, \p{Nd}+, there was the theoretical possibility of
312        setting up an incorrect bitmap of starting bytes, but fortunately it could
313        not have actually happened in practice until change 8 above was made (it
314        added property types that matched character-matching opcodes).
315    
316    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
317        possible starting bytes for non-anchored patterns.
318    
319    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
320        \R, and also a number of cases that involve Unicode properties, both
321        explicit and implicit when PCRE_UCP is set.
322    
323    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
324        input, it could crash or give wrong results if characters with values
325        greater than 0xc0 were present in the subject string. (Detail: it assumed
326        UTF-8 input when processing these items.)
327    
328    16. Added a lot of (int) casts to avoid compiler warnings in systems where
329        size_t is 64-bit (#991).
330    
331    17. Added a check for running out of memory when PCRE is compiled with
332        --disable-stack-for-recursion (#990).
333    
334    18. If the last data line in a file for pcretest does not have a newline on
335        the end, a newline was missing in the output.
336    
337    19. The default pcre_chartables.c file recognizes only ASCII characters (values
338        less than 128) in its various bitmaps. However, there is a facility for
339        generating tables according to the current locale when PCRE is compiled. It
340        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
341        characters, are recognized by isspace() and therefore were getting set in
342        these tables, and indeed these tables seem to approximate to ISO 8859. This
343        caused a problem in UTF-8 mode when pcre_study() was used to create a list
344        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
345        which of course cannot start UTF-8 characters. I have changed the code so
346        that only real ASCII characters (less than 128) and the correct starting
347        bytes for UTF-8 encodings are set for characters greater than 127 when in
348        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
349        altogether.)
350    
351    20. Added the /T option to pcretest so as to be able to run tests with non-
352        standard character tables, thus making it possible to include the tests
353        used for 19 above in the standard set of tests.
354    
355    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
356        reference to a subpattern the other side of a comment that contains an
357        opening parenthesis caused either an internal compiling error, or a
358        reference to the wrong subpattern.
359    
360    
361    Version 8.02 19-Mar-2010
362    ------------------------
363    
364    1.  The Unicode data tables have been updated to Unicode 5.2.0.
365    
366    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
367        configured.
368    
369    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
370        original author of that file, following a query about its status.
371    
372    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
373        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
374    
375    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
376        quantifier applied to a forward-referencing subroutine call, could compile
377        incorrect code or give the error "internal error: previously-checked
378        referenced subpattern not found".
379    
380    6.  Both MS Visual Studio and Symbian OS have problems with initializing
381        variables to point to external functions. For these systems, therefore,
382        pcre_malloc etc. are now initialized to local functions that call the
383        relevant global functions.
384    
385    7.  There were two entries missing in the vectors called coptable and poptable
386        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
387        I've fixed the data, and added a kludgy way of testing at compile time that
388        the lengths are correct (equal to the number of opcodes).
389    
390    8.  Following on from 7, I added a similar kludge to check the length of the
391        eint vector in pcreposix.c.
392    
393    9.  Error texts for pcre_compile() are held as one long string to avoid too
394        much relocation at load time. To find a text, the string is searched,
395        counting zeros. There was no check for running off the end of the string,
396        which could happen if a new error number was added without updating the
397        string.
398    
399    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
400    
401    11. \K was not working if it appeared in an atomic group or in a group that
402        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
403        \K is "not well defined" if used in an assertion. PCRE now accepts it if
404        the assertion is positive, but not if it is negative.
405    
406    12. Change 11 fortuitously reduced the size of the stack frame used in the
407        "match()" function of pcre_exec.c by one pointer. Forthcoming
408        implementation of support for (*MARK) will need an extra pointer on the
409        stack; I have reserved it now, so that the stack frame size does not
410        decrease.
411    
412    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
413        item in branch that calls a recursion is a subroutine call - as in the
414        second branch in the above example - was incorrectly given the compile-
415        time error "recursive call could loop indefinitely" because pcre_compile()
416        was not correctly checking the subroutine for matching a non-empty string.
417    
418    14. The checks for overrunning compiling workspace could trigger after an
419        overrun had occurred. This is a "should never occur" error, but it can be
420        triggered by pathological patterns such as hundreds of nested parentheses.
421        The checks now trigger 100 bytes before the end of the workspace.
422    
423    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
424    
425    
426    Version 8.01 19-Jan-2010
427    ------------------------
428    
429    1.  If a pattern contained a conditional subpattern with only one branch (in
430        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
431        computed the wrong minimum data length (which is of course zero for such
432        subpatterns). This could cause incorrect "no match" results.
433    
434    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
435        the pattern is reset in the first branch, pcre_compile() failed with
436        "internal error: code overflow at offset...". This happened only when
437        the reset was to the original external option setting. (An optimization
438        abstracts leading options settings into an external setting, which was the
439        cause of this.)
440    
441    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
442        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
443        assertion pattern did not match (meaning that the assertion was true), it
444        was incorrectly treated as false if the SKIP had been reached during the
445        matching. This also applied to assertions used as conditions.
446    
447    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
448        assertion subpattern, including such a pattern used as a condition,
449        unpredictable results occurred, instead of the error return
450        PCRE_ERROR_DFA_UITEM.
451    
452    5.  The C++ GlobalReplace function was not working like Perl for the special
453        situation when an empty string is matched. It now does the fancy magic
454        stuff that is necessary.
455    
456    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
457        removed. (These were left over from very, very early versions of PCRE.)
458    
459    7.  Some cosmetic changes to the code to make life easier when compiling it
460        as part of something else:
461    
462        (a) Change DEBUG to PCRE_DEBUG.
463    
464        (b) In pcre_compile(), rename the member of the "branch_chain" structure
465            called "current" as "current_branch", to prevent a collision with the
466            Linux macro when compiled as a kernel module.
467    
468        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
469            prevent a collision with the Linux macro when compiled as a kernel
470            module.
471    
472    8.  In pcre_compile() there are some checks for integer overflows that used to
473        cast potentially large values to (double). This has been changed to that
474        when building, a check for int64_t is made, and if it is found, it is used
475        instead, thus avoiding the use of floating point arithmetic. (There is no
476        other use of FP in PCRE.) If int64_t is not found, the fallback is to
477        double.
478    
479    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
480        2005 (difference between two addresses compared to an unsigned value).
481    
482    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
483        custom one, because of the following reported problem in Windows:
484    
485          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
486              under Win32.
487          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
488              therefore missing the function definition.
489          - The compiler thus generates a "C" signature for the test function.
490          - The linker fails to find the "C" function.
491          - PCRE fails to configure if asked to do so against libbz2.
492    
493    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
494        messages were output:
495    
496          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
497          rerunning libtoolize, to keep the correct libtool macros in-tree.
498          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
499    
500        I have done both of these things.
501    
502    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
503        most of the time, it *can* run out if it is given a pattern that contains a
504        runaway infinite recursion. I updated the discussion in the pcrestack man
505        page.
506    
507    13. Now that we have gone to the x.xx style of version numbers, the minor
508        version may start with zero. Using 08 or 09 is a bad idea because users
509        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
510        interpreted as invalid octal numbers. I've updated the previous comment in
511        configure.ac, and also added a check that gives an error if 08 or 09 are
512        used.
513    
514    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
515        causing partial matching to fail when the end of the subject matched \W
516        in a UTF-8 pattern where \W was quantified with a minimum of 3.
517    
518    15. There were some discrepancies between the declarations in pcre_internal.h
519        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
520        their definitions. The declarations used "const uschar *" and the
521        definitions used USPTR. Even though USPTR is normally defined as "const
522        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
523        reported that: "This difference in casting confuses some C++ compilers, for
524        example, SunCC recognizes above declarations as different functions and
525        generates broken code for hbpcre." I have changed the declarations to use
526        USPTR.
527    
528    16. GNU libtool is named differently on some systems. The autogen.sh script now
529        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
530        (FreeBSD).
531    
532    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
533        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
534        comment: "Figure out how to create a longlong from a string: strtoll and
535        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
536        instance, but it only takes 2 args instead of 3!"
537    
538    18. A subtle bug concerned with back references has been fixed by a change of
539        specification, with a corresponding code fix. A pattern such as
540        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
541        refers, was giving matches when it shouldn't. For example, xa=xaaa would
542        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
543        same bug. Such groups have to be quantified to be useful, or contained
544        inside another quantified group. (If there's no repetition, the reference
545        can never match.) The problem arises because, having left the group and
546        moved on to the rest of the pattern, a later failure that backtracks into
547        the group uses the captured value from the final iteration of the group
548        rather than the correct earlier one. I have fixed this in PCRE by forcing
549        any group that contains a reference to itself to be an atomic group; that
550        is, there cannot be any backtracking into it once it has completed. This is
551        similar to recursive and subroutine calls.
552    
553    
554    Version 8.00 19-Oct-09
555    ----------------------
556    
557    1.  The table for translating pcre_compile() error codes into POSIX error codes
558        was out-of-date, and there was no check on the pcre_compile() error code
559        being within the table. This could lead to an OK return being given in
560        error.
561    
562    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
563        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
564        in a Windows environment.
565    
566    3.  The pcregrep --count option prints the count for each file even when it is
567        zero, as does GNU grep. However, pcregrep was also printing all files when
568        --files-with-matches was added. Now, when both options are given, it prints
569        counts only for those files that have at least one match. (GNU grep just
570        prints the file name in this circumstance, but including the count seems
571        more useful - otherwise, why use --count?) Also ensured that the
572        combination -clh just lists non-zero counts, with no names.
573    
574    4.  The long form of the pcregrep -F option was incorrectly implemented as
575        --fixed_strings instead of --fixed-strings. This is an incompatible change,
576        but it seems right to fix it, and I didn't think it was worth preserving
577        the old behaviour.
578    
579    5.  The command line items --regex=pattern and --regexp=pattern were not
580        recognized by pcregrep, which required --regex pattern or --regexp pattern
581        (with a space rather than an '='). The man page documented the '=' forms,
582        which are compatible with GNU grep; these now work.
583    
584    6.  No libpcreposix.pc file was created for pkg-config; there was just
585        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
586    
587    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
588        when UCP support is not needed, by modifying the Python script that
589        generates it from Unicode data files. This should not matter if the module
590        is correctly used as a library, but I received one complaint about 50K of
591        unwanted data. My guess is that the person linked everything into his
592        program rather than using a library. Anyway, it does no harm.
593    
594    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
595        was a minimum greater than 1 for a wide character in a possessive
596        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
597        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
598        character. Chaos in the form of incorrect output or a compiling loop could
599        result.
600    
601    9.  The restrictions on what a pattern can contain when partial matching is
602        requested for pcre_exec() have been removed. All patterns can now be
603        partially matched by this function. In addition, if there are at least two
604        slots in the offset vector, the offset of the earliest inspected character
605        for the match and the offset of the end of the subject are set in them when
606        PCRE_ERROR_PARTIAL is returned.
607    
608    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
609        synonymous with PCRE_PARTIAL, for backwards compatibility, and
610        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
611        and may be more useful for multi-segment matching.
612    
613    11. Partial matching with pcre_exec() is now more intuitive. A partial match
614        used to be given if ever the end of the subject was reached; now it is
615        given only if matching could not proceed because another character was
616        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
617        string "Z", which now yields "no match" instead of "partial match". In the
618        case of pcre_dfa_exec(), "no match" is given if every matching path for the
619        final character ended with (*FAIL).
620    
621    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
622        if the pattern had a "must contain" character that was already found in the
623        earlier partial match, unless partial matching was again requested. For
624        example, with the pattern /dog.(body)?/, the "must contain" character is
625        "g". If the first part-match was for the string "dog", restarting with
626        "sbody" failed. This bug has been fixed.
627    
628    13. The string returned by pcre_dfa_exec() after a partial match has been
629        changed so that it starts at the first inspected character rather than the
630        first character of the match. This makes a difference only if the pattern
631        starts with a lookbehind assertion or \b or \B (\K is not supported by
632        pcre_dfa_exec()). It's an incompatible change, but it makes the two
633        matching functions compatible, and I think it's the right thing to do.
634    
635    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
636        so that the demonstration program is easily available in environments where
637        PCRE has not been installed from source.
638    
639    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
640        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
641        library.
642    
643    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
644        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
645        is not the first non-POSIX option to be added. Clearly some people find
646        these options useful.
647    
648    17. If a caller to the POSIX matching function regexec() passes a non-zero
649        value for nmatch with a NULL value for pmatch, the value of
650        nmatch is forced to zero.
651    
652    18. RunGrepTest did not have a test for the availability of the -u option of
653        the diff command, as RunTest does. It now checks in the same way as
654        RunTest, and also checks for the -b option.
655    
656    19. If an odd number of negated classes containing just a single character
657        interposed, within parentheses, between a forward reference to a named
658        subpattern and the definition of the subpattern, compilation crashed with
659        an internal error, complaining that it could not find the referenced
660        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
661        [The bug was that it was starting one character too far in when skipping
662        over the character class, thus treating the ] as data rather than
663        terminating the class. This meant it could skip too much.]
664    
665    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
666        /g option in pcretest when the pattern contains \K, which makes it possible
667        to have an empty string match not at the start, even when the pattern is
668        anchored. Updated pcretest and pcredemo to use this option.
669    
670    21. If the maximum number of capturing subpatterns in a recursion was greater
671        than the maximum at the outer level, the higher number was returned, but
672        with unset values at the outer level. The correct (outer level) value is
673        now given.
674    
675    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
676        PCRE did not set those parentheses (unlike Perl). I have now found a way to
677        make it do so. The string so far is captured, making this feature
678        compatible with Perl.
679    
680    23. The tests have been re-organized, adding tests 11 and 12, to make it
681        possible to check the Perl 5.10 features against Perl 5.10.
682    
683    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
684        pattern matches a fixed length string. PCRE did not allow this; now it
685        does. Neither allows recursion.
686    
687    25. I finally figured out how to implement a request to provide the minimum
688        length of subject string that was needed in order to match a given pattern.
689        (It was back references and recursion that I had previously got hung up
690        on.) This code has now been added to pcre_study(); it finds a lower bound
691        to the length of subject needed. It is not necessarily the greatest lower
692        bound, but using it to avoid searching strings that are too short does give
693        some useful speed-ups. The value is available to calling programs via
694        pcre_fullinfo().
695    
696    26. While implementing 25, I discovered to my embarrassment that pcretest had
697        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
698        study optimizations had never been tested with that matching function.
699        Oops. What is worse, even when it was passed study data, there was a bug in
700        pcre_dfa_exec() that meant it never actually used it. Double oops. There
701        were also very few tests of studied patterns with pcre_dfa_exec().
702    
703    27. If (?| is used to create subpatterns with duplicate numbers, they are now
704        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
705        on the other side of the coin, they are no longer allowed to have different
706        names, because these cannot be distinguished in PCRE, and this has caused
707        confusion. (This is a difference from Perl.)
708    
709    28. When duplicate subpattern names are present (necessarily with different
710        numbers, as required by 27 above), and a test is made by name in a
711        conditional pattern, either for a subpattern having been matched, or for
712        recursion in such a pattern, all the associated numbered subpatterns are
713        tested, and the overall condition is true if the condition is true for any
714        one of them. This is the way Perl works, and is also more like the way
715        testing by number works.
716    
717    
718    Version 7.9 11-Apr-09
719    ---------------------
720    
721    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
722        (pcretest), all targets were linked against these libraries. This included
723        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
724        libraries. This caused unwanted dependencies to be created. This problem
725        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
726        pcretest is linked with readline.
727    
728    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
729        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
730        moved outside it again, because FALSE and TRUE are already defined in AIX,
731        but BOOL is not.
732    
733    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
734        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
735    
736    4.  The pcregrep documentation said spaces were inserted as well as colons (or
737        hyphens) following file names and line numbers when outputting matching
738        lines. This is not true; no spaces are inserted. I have also clarified the
739        wording for the --colour (or --color) option.
740    
741    5.  In pcregrep, when --colour was used with -o, the list of matching strings
742        was not coloured; this is different to GNU grep, so I have changed it to be
743        the same.
744    
745    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
746        each matching line was coloured. Now it goes on to look for further matches
747        of any of the test patterns, which is the same behaviour as GNU grep.
748    
749    7.  A pattern that could match an empty string could cause pcregrep to loop; it
750        doesn't make sense to accept an empty string match in pcregrep, so I have
751        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
752        seems to be how GNU grep behaves.
753    
754    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
755        start or after a newline", because the conditional assertion was not being
756        correctly handled. The rule now is that both the assertion and what follows
757        in the first alternative must satisfy the test.
758    
759    9.  If auto-callout was enabled in a pattern with a conditional group whose
760        condition was an assertion, PCRE could crash during matching, both with
761        pcre_exec() and pcre_dfa_exec().
762    
763    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
764        used for matching.
765    
766    11. Unicode property support in character classes was not working for
767        characters (bytes) greater than 127 when not in UTF-8 mode.
768    
769    12. Added the -M command line option to pcretest.
770    
771    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
772    
773    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
774    
775    16. Added comments and documentation about mis-use of no_arg in the C++
776        wrapper.
777    
778    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
779        from Martin Jerabek that uses macro names for all relevant character and
780        string constants.
781    
782    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
783        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
784        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
785        these, but not everybody uses configure.
786    
787    19. A conditional group that had only one branch was not being correctly
788        recognized as an item that could match an empty string. This meant that an
789        enclosing group might also not be so recognized, causing infinite looping
790        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
791        with the subject "ab", where knowledge that the repeated group can match
792        nothing is needed in order to break the loop.
793    
794    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
795        exec(), but without supplying a callout function, matching went wrong.
796    
797    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
798        leak if the size of the offset vector was greater than 30. When the vector
799        is smaller, the saved offsets during recursion go onto a local stack
800        vector, but for larger vectors malloc() is used. It was failing to free
801        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
802        error, in fact).
803    
804    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
805        heapframe that is used only when UTF-8 support is enabled. This caused no
806        problem, but was untidy.
807    
808    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
809        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
810        included within another project.
811    
812    24. Steven Van Ingelgem's patches to add more options to the CMake support,
813        slightly modified by me:
814    
815          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
816              not building pcregrep.
817    
818          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
819              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
820    
821    25. Forward references, both numeric and by name, in patterns that made use of
822        duplicate group numbers, could behave incorrectly or give incorrect errors,
823        because when scanning forward to find the reference group, PCRE was not
824        taking into account the duplicate group numbers. A pattern such as
825        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
826    
827    26. Changed a few more instances of "const unsigned char *" to USPTR, making
828        the feature of a custom pointer more persuasive (as requested by a user).
829    
830    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
831        pcretest.c, inside #ifndefs, because it seems they are sometimes already
832        pre-defined.
833    
834    28. Added support for (*UTF8) at the start of a pattern.
835    
836    29. Arrange for flags added by the "release type" setting in CMake to be shown
837        in the configuration summary.
838    
839    
840    Version 7.8 05-Sep-08
841    ---------------------
842    
843    1.  Replaced UCP searching code with optimized version as implemented for Ad
844        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
845        stage table and inline lookup instead of a function, giving speed ups of 2
846        to 5 times on some simple patterns that I tested. Permission was given to
847        distribute the MultiStage2.py script that generates the tables (it's not in
848        the tarball, but is in the Subversion repository).
849    
850    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
851        scripts.
852    
853    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
854        a group with a zero qualifier. The result of the study could be incorrect,
855        or the function might crash, depending on the pattern.
856    
857    4.  Caseless matching was not working for non-ASCII characters in back
858        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
859        It now works when Unicode Property Support is available.
860    
861    5.  In pcretest, an escape such as \x{de} in the data was always generating
862        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
863        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
864        truncation.
865    
866    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
867    
868    7.  Added two (int) casts to pcregrep when printing the difference of two
869        pointers, in case they are 64-bit values.
870    
871    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
872        test 2 if it fails.
873    
874    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
875        and a #define of that name to empty if it is not externally set. This is to
876        allow users of MSVC to set it if necessary.
877    
878    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
879        the convenience functions in the pcre_get.c source file.
880    
881    11. An option change at the start of a pattern that had top-level alternatives
882        could cause overwriting and/or a crash. This command provoked a crash in
883        some environments:
884    
885          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
886    
887        This potential security problem was recorded as CVE-2008-2371.
888    
889    12. For a pattern where the match had to start at the beginning or immediately
890        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
891        pcre_dfa_exec() could read past the end of the passed subject if there was
892        no match. To help with detecting such bugs (e.g. with valgrind), I modified
893        pcretest so that it places the subject at the end of its malloc-ed buffer.
894    
895    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
896        exec() might read past the end of the data buffer in UTF-8 mode.
897    
898    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
899        the data contained the byte 0x85 as part of a UTF-8 character within its
900        first line. This applied both to normal and DFA matching.
901    
902    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
903        /^[^d]*?$/8 failed to match "abc".
904    
905    16. Added a missing copyright notice to pcrecpp_internal.h.
906    
907    17. Make it more clear in the documentation that values returned from
908        pcre_exec() in ovector are byte offsets, not character counts.
909    
910    18. Tidied a few places to stop certain compilers from issuing warnings.
911    
912    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
913        supplied by Stefan Weber. I made a further small update for 7.8 because
914        there is a change of source arrangements: the pcre_searchfuncs.c module is
915        replaced by pcre_ucd.c.
916    
917    
918    Version 7.7 07-May-08
919    ---------------------
920    
921    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
922        a string to a long long, pretend we don't even have a long long." This is
923        done by checking for the strtoq, strtoll, and _strtoi64 functions.
924    
925    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
926        pre-7.6 versions, which defined a global no_arg variable instead of putting
927        it in the RE class. (See also #8 below.)
928    
929    3.  Remove a line of dead code, identified by coverity and reported by Nuno
930        Lopes.
931    
932    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
933    
934        (1) The include/exclude patterns were being applied to the whole pathnames
935            of files, instead of just to the final components.
936    
937        (2) If there was more than one level of directory, the subdirectories were
938            skipped unless they satisfied the include/exclude conditions. This is
939            inconsistent with GNU grep (and could even be seen as contrary to the
940            pcregrep specification - which I improved to make it absolutely clear).
941            The action now is always to scan all levels of directory, and just
942            apply the include/exclude patterns to regular files.
943    
944    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
945        --exclude_dir in the tests to avoid scanning .svn directories.
946    
947    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
948        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
949        doesn't support NULs in patterns.
950    
951    7.  Added some missing "const"s to declarations of static tables in
952        pcre_compile.c and pcre_dfa_exec.c.
953    
954    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
955        caused by fix #2  above. (Subsequently also a second patch to fix the
956        first patch. And a third patch - this was a messy problem.)
957    
958    9.  Applied Craig's patch to remove the use of push_back().
959    
960    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
961        matching function regexec().
962    
963    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
964        which, however, unlike Perl's \g{...}, are subroutine calls, not back
965        references. PCRE supports relative numbers with this syntax (I don't think
966        Oniguruma does).
967    
968    12. Previously, a group with a zero repeat such as (...){0} was completely
969        omitted from the compiled regex. However, this means that if the group
970        was called as a subroutine from elsewhere in the pattern, things went wrong
971        (an internal error was given). Such groups are now left in the compiled
972        pattern, with a new opcode that causes them to be skipped at execution
973        time.
974    
975    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
976        to the way PCRE behaves:
977    
978        (a) A lone ] character is dis-allowed (Perl treats it as data).
979    
980        (b) A back reference to an unmatched subpattern matches an empty string
981            (Perl fails the current match path).
982    
983        (c) A data ] in a character class must be notated as \] because if the
984            first data character in a class is ], it defines an empty class. (In
985            Perl it is not possible to have an empty class.) The empty class []
986            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
987            The negative empty class [^] matches any one character, independently
988            of the DOTALL setting.
989    
990    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
991        non-existent subpattern following a character class starting with ']' and
992        containing () gave an internal compiling error instead of "reference to
993        non-existent subpattern". Fortunately, when the pattern did exist, the
994        compiled code was correct. (When scanning forwards to check for the
995        existencd of the subpattern, it was treating the data ']' as terminating
996        the class, so got the count wrong. When actually compiling, the reference
997        was subsequently set up correctly.)
998    
999    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1000        it was being rejected as not supported by pcre_dfa_exec(), even though
1001        other assertions are supported. I have made pcre_dfa_exec() support
1002        (*FAIL).
1003    
1004    16. The implementation of 13c above involved the invention of a new opcode,
1005        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1006        cannot be changed at match time, I realized I could make a small
1007        improvement to matching performance by compiling OP_ALLANY instead of
1008        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1009        on the OP_ANY path.
1010    
1011    17. Compiling pcretest on Windows with readline support failed without the
1012        following two fixes: (1) Make the unistd.h include conditional on
1013        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1014    
1015    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1016        ncurses library to be included for pcretest when ReadLine support is
1017        requested, but also to allow for it to be overridden. This patch came from
1018        Daniel Bergström.
1019    
1020    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1021        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1022        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1023        spotting this.
1024    
1025    
1026    Version 7.6 28-Jan-08
1027    ---------------------
1028    
1029    1.  A character class containing a very large number of characters with
1030        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1031        overflow.
1032    
1033    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1034        HAVE_LONG_LONG is not defined.
1035    
1036    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1037        bring them up to date and include new features. This patch includes:
1038    
1039        - Fixed PH's badly added libz and libbz2 support.
1040        - Fixed a problem with static linking.
1041        - Added pcredemo. [But later removed - see 7 below.]
1042        - Fixed dftables problem and added an option.
1043        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1044            HAVE_LONG_LONG.
1045        - Added readline support for pcretest.
1046        - Added an listing of the option settings after cmake has run.
1047    
1048    4.  A user submitted a patch to Makefile that makes it easy to create
1049        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1050        Makefile.am that cause it to include this special target, without
1051        affecting anything else. Note that the same mingw target plus all
1052        the other distribution libraries and programs are now supported
1053        when configuring with CMake (see 6 below) instead of with
1054        Configure/Make.
1055    
1056    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1057        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1058        exported in the Windows port". It has not yet been confirmed that the patch
1059        solves the problem, but it does no harm.
1060    
1061    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1062        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1063        with CMake, and also correct the comment about stack recursion.
1064    
1065    7.  Remove the automatic building of pcredemo from the ./configure system and
1066        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1067        of a program that users should build themselves after PCRE is installed, so
1068        building it automatically is not really right. What is more, it gave
1069        trouble in some build environments.
1070    
1071    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1072    
1073    
1074    Version 7.5 10-Jan-08
1075    ---------------------
1076    
1077    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1078        values in parens when parsing an RE using the C++ wrapper."
1079    
1080    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1081        Characters greater than 255 were excluded from the class instead of being
1082        included.
1083    
1084    3.  The same bug as (2) above applied to negated POSIX classes such as
1085        [:^space:].
1086    
1087    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1088        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1089        I have changed it.
1090    
1091    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1092        first named subpattern) and a construct such as (?&a) would reference the
1093        first named subpattern whose name started with "a" (in other words, the
1094        length check was missing). Both these problems are fixed. "Subpattern name
1095        expected" is now given for (?&) (a zero-length name), and this patch also
1096        makes it give the same error for \k'' (previously it complained that that
1097        was a reference to a non-existent subpattern).
1098    
1099    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1100        this is right because (?- can be followed by option settings as well as by
1101        digits. I have, however, made the messages clearer.
1102    
1103    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1104        than the number used in the conditional) now cause a compile-time error.
1105        This is actually not compatible with Perl, which accepts such patterns, but
1106        treats the conditional as always being FALSE (as PCRE used to), but it
1107        seems to me that giving a diagnostic is better.
1108    
1109    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1110        and messages.
1111    
1112    9.  Fix two occurrences of "backslash" in comments that should have been
1113        "backspace".
1114    
1115    10. Remove two redundant lines of code that can never be obeyed (their function
1116        was moved elsewhere).
1117    
1118    11. The program that makes PCRE's Unicode character property table had a bug
1119        which caused it to generate incorrect table entries for sequences of
1120        characters that have the same character type, but are in different scripts.
1121        It amalgamated them into a single range, with the script of the first of
1122        them. In other words, some characters were in the wrong script. There were
1123        thirteen such cases, affecting characters in the following ranges:
1124    
1125          U+002b0 - U+002c1
1126          U+0060c - U+0060d
1127          U+0061e - U+00612
1128          U+0064b - U+0065e
1129          U+0074d - U+0076d
1130          U+01800 - U+01805
1131          U+01d00 - U+01d77
1132          U+01d9b - U+01dbf
1133          U+0200b - U+0200f
1134          U+030fc - U+030fe
1135          U+03260 - U+0327f
1136          U+0fb46 - U+0fbb1
1137          U+10450 - U+1049d
1138    
1139    12. The -o option (show only the matching part of a line) for pcregrep was not
1140        compatible with GNU grep in that, if there was more than one match in a
1141        line, it showed only the first of them. It now behaves in the same way as
1142        GNU grep.
1143    
1144    13. If the -o and -v options were combined for pcregrep, it printed a blank
1145        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1146        does the same. The return code can be used to tell if there were any
1147        non-matching lines.
1148    
1149    14. Added --file-offsets and --line-offsets to pcregrep.
1150    
1151    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1152        infinitely looping recursion. The bug was that positive lookaheads were not
1153        being skipped when checking for a possible empty match (negative lookaheads
1154        and both kinds of lookbehind were skipped).
1155    
1156    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1157        inclusion of <windows.h> to before rather than after the definition of
1158        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1159    
1160    17. Specifying a possessive quantifier with a specific limit for a Unicode
1161        character property caused pcre_compile() to compile bad code, which led at
1162        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1163        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1164        caused the error; without that there was no problem.
1165    
1166    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1167    
1168    19. Added --enable-pcretest-libreadline.
1169    
1170    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1171        RE::GlobalReplace(). As a result, the number of replacements returned was
1172        double what it should be. I removed one of the increments, but Craig sent a
1173        later patch that removed the other one (the right fix) and added unit tests
1174        that check the return values (which was not done before).
1175    
1176    21. Several CMake things:
1177    
1178        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1179            the names libpcre and libpcreposix, not just pcre and pcreposix.
1180    
1181        (2) The above change means that pcretest and pcregrep are now correctly
1182            linked with the newly-built libraries, not previously installed ones.
1183    
1184        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1185    
1186    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1187        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1188        UTF-8 newline character). The key issue is that the pattern starts .*;
1189        this means that the match must be either at the beginning, or after a
1190        newline. The bug was in the code for advancing after a failed match and
1191        checking that the new position followed a newline. It was not taking
1192        account of UTF-8 characters correctly.
1193    
1194    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1195        character classes. PCRE was not treating the sequence [:...:] as a
1196        character class unless the ... were all letters. Perl, however, seems to
1197        allow any characters between [: and :], though of course it rejects as
1198        unknown any "names" that contain non-letters, because all the known class
1199        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1200        for example, whereas PCRE did not - it did not recognize a POSIX character
1201        class. This seemed a bit dangerous, so the code has been changed to be
1202        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1203        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1204        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1205        Perl does, and where it didn't before.
1206    
1207    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1208        Windows environments %n is disabled by default.
1209    
1210    
1211    Version 7.4 21-Sep-07
1212    ---------------------
1213    
1214    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1215        means that a class such as [\s] counted as "explicit reference to CR or
1216        LF". That isn't really right - the whole point of the change was to try to
1217        help when there was an actual mention of one of the two characters. So now
1218        the change happens only if \r or \n (or a literal CR or LF) character is
1219        encountered.
1220    
1221    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1222        of both had grown to the point where there were only 3 bits left.
1223        Fortunately, there was spare space in the data structure, and so I have
1224        moved the internal flags into a new 16-bit field to free up more option
1225        bits.
1226    
1227    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1228        but did not set the internal JCHANGED flag - either of these is enough to
1229        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1230        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1231        start sets both bits.
1232    
1233    4.  Added options (at build time, compile time, exec time) to change \R from
1234        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1235    
1236    5.  doc/pcresyntax.html was missing from the distribution.
1237    
1238    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1239        compatibility, even though it is no longer used.
1240    
1241    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1242        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1243        windows.h file is present (where different names are used). [This was
1244        reversed later after testing - see 16 below.]
1245    
1246    8.  Changed all #include <config.h> to #include "config.h". There were also
1247        some further <pcre.h> cases that I changed to "pcre.h".
1248    
1249    9.  When pcregrep was used with the --colour option, it missed the line ending
1250        sequence off the lines that it output.
1251    
1252    10. It was pointed out to me that arrays of string pointers cause lots of
1253        relocations when a shared library is dynamically loaded. A technique of
1254        using a single long string with a table of offsets can drastically reduce
1255        these. I have refactored PCRE in four places to do this. The result is
1256        dramatic:
1257    
1258          Originally:                          290
1259          After changing UCP table:            187
1260          After changing error message table:   43
1261          After changing table of "verbs"       36
1262          After changing table of Posix names   22
1263    
1264        Thanks to the folks working on Gregex for glib for this insight.
1265    
1266    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1267        unicode-properties was also set.
1268    
1269    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1270    
1271    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1272        checked only for CRLF.
1273    
1274    14. Added casts to pcretest.c to avoid compiler warnings.
1275    
1276    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1277    
1278    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1279        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1280        entirely. This removes changes made in 7 above.
1281    
1282    17. The CMake files have been updated, and there is now more information about
1283        building with CMake in the NON-UNIX-USE document.
1284    
1285    
1286    Version 7.3 28-Aug-07
1287    ---------------------
1288    
1289     1. In the rejigging of the build system that eventually resulted in 7.1, the
1290        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1291        brackets there is not right, since it causes compilers to look for an
1292        installed pcre.h, not the version that is in the source that is being
1293        compiled (which of course may be different). I have changed it back to:
1294    
1295          #include "pcre.h"
1296    
1297        I have a vague recollection that the change was concerned with compiling in
1298        different directories, but in the new build system, that is taken care of
1299        by the VPATH setting the Makefile.
1300    
1301     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1302        when the subject happened to end in the byte 0x85 (e.g. if the last
1303        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1304        characters but of course it shouldn't be taken as a newline when it is part
1305        of another character. The bug was that, for an unlimited repeat of . in
1306        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1307        characters when looking for a newline.
1308    
1309     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1310    
1311     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1312        in debug output.
1313    
1314     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1315        long printing in the pcrecpp unittest when running under MinGW.
1316    
1317     6. ESC_K was left out of the EBCDIC table.
1318    
1319     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1320        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1321        limit also applies to "virtual nesting" when a pattern is recursive, and in
1322        this case 1000 isn't so big. I have been able to remove this limit at the
1323        expense of backing off one optimization in certain circumstances. Normally,
1324        when pcre_exec() would call its internal match() function recursively and
1325        immediately return the result unconditionally, it uses a "tail recursion"
1326        feature to save stack. However, when a subpattern that can match an empty
1327        string has an unlimited repetition quantifier, it no longer makes this
1328        optimization. That gives it a stack frame in which to save the data for
1329        checking that an empty string has been matched. Previously this was taken
1330        from the 1000-entry workspace that had been reserved. So now there is no
1331        explicit limit, but more stack is used.
1332    
1333     8. Applied Daniel's patches to solve problems with the import/export magic
1334        syntax that is required for Windows, and which was going wrong for the
1335        pcreposix and pcrecpp parts of the library. These were overlooked when this
1336        problem was solved for the main library.
1337    
1338     9. There were some crude static tests to avoid integer overflow when computing
1339        the size of patterns that contain repeated groups with explicit upper
1340        limits. As the maximum quantifier is 65535, the maximum group length was
1341        set at 30,000 so that the product of these two numbers did not overflow a
1342        32-bit integer. However, it turns out that people want to use groups that
1343        are longer than 30,000 bytes (though not repeat them that many times).
1344        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1345        made it possible to implement the integer overflow checks in a much more
1346        dynamic way, which I have now done. The artificial limitation on group
1347        length has been removed - we now have only the limit on the total length of
1348        the compiled pattern, which depends on the LINK_SIZE setting.
1349    
1350    10. Fixed a bug in the documentation for get/copy named substring when
1351        duplicate names are permitted. If none of the named substrings are set, the
1352        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1353        empty string.
1354    
1355    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1356        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1357        because the ] is interpreted as the first data character and the
1358        terminating ] is not found. PCRE has been made compatible with Perl in this
1359        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1360        cause memory overwriting.
1361    
1362    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1363        string has been matched (to stop an infinite loop). It was not recognizing
1364        a conditional subpattern that could match an empty string if that
1365        subpattern was within another subpattern. For example, it looped when
1366        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1367        condition was not nested. This bug has been fixed.
1368    
1369    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1370        past the start of the subject in the presence of bytes with the top bit
1371        set, for example "\x8aBCD".
1372    
1373    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1374        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1375    
1376    14. Optimized (?!) to (*FAIL).
1377    
1378    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1379        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1380        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1381        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1382        does: it's just the validity check that is more restrictive.
1383    
1384    16. Inserted checks for integer overflows during escape sequence (backslash)
1385        processing, and also fixed erroneous offset values for syntax errors during
1386        backslash processing.
1387    
1388    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1389        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1390    
1391    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1392        caused an overrun.
1393    
1394    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1395        something other than just ASCII characters) inside a group that had an
1396        unlimited repeat caused a loop at compile time (while checking to see
1397        whether the group could match an empty string).
1398    
1399    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1400        [\P{Any}] did so. (Error in the code for printing property names.)
1401    
1402    21. An orphan \E inside a character class could cause a crash.
1403    
1404    22. A repeated capturing bracket such as (A)? could cause a wild memory
1405        reference during compilation.
1406    
1407    23. There are several functions in pcre_compile() that scan along a compiled
1408        expression for various reasons (e.g. to see if it's fixed length for look
1409        behind). There were bugs in these functions when a repeated \p or \P was
1410        present in the pattern. These operators have additional parameters compared
1411        with \d, etc, and these were not being taken into account when moving along
1412        the compiled data. Specifically:
1413    
1414        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1415            length.
1416    
1417        (b) An item such as \pL+ within a repeated group could cause crashes or
1418            loops.
1419    
1420        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1421            "reference to non-existent subpattern" error.
1422    
1423        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1424    
1425    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1426        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1427    
1428    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1429    
1430    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1431        character were causing crashes (broken optimization).
1432    
1433    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1434        \p or \P) caused a compile-time loop.
1435    
1436    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1437        break. For example, the unstudied pattern [\r\n]A does not match the string
1438        "\r\nA" because change 7.0/46 below moves the current point on by two
1439        characters after failing to match at the start. However, the pattern \nA
1440        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1441        the same is true. There doesn't seem any very clean way out of this, but
1442        what I have chosen to do makes the common cases work: PCRE now takes note
1443        of whether there can be an explicit match for \r or \n anywhere in the
1444        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1445        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1446        pattern has explicit CR or LF references.
1447    
1448    29. Added (*CR) etc for changing newline setting at start of pattern.
1449    
1450    
1451    Version 7.2 19-Jun-07
1452    ---------------------
1453    
1454     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1455        which is apparently normally available under Windows.
1456    
1457     2. Re-jig the pcregrep tests with different newline settings in an attempt
1458        to make them independent of the local environment's newline setting.
1459    
1460     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1461    
1462     4. Some of the "internals" tests were previously cut out when the link size
1463        was not 2, because the output contained actual offsets. The recent new
1464        "Z" feature of pcretest means that these can be cut out, making the tests
1465        usable with all link sizes.
1466    
1467     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1468        stack recursion. This gives a massive performance boost under BSD, but just
1469        a small improvement under Linux. However, it saves one field in the frame
1470        in all cases.
1471    
1472     6. Added more features from the forthcoming Perl 5.10:
1473    
1474        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1475            recursion call. It refers to the nth most recently opened parentheses.
1476    
1477        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1478            to be opened parentheses.
1479    
1480        (c) Conditions that refer to capturing parentheses can be specified
1481            relatively, for example, (?(-2)... or (?(+3)...
1482    
1483        (d) \K resets the start of the current match so that everything before
1484            is not part of it.
1485    
1486        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1487    
1488        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1489            reference syntax.
1490    
1491        (g) (?| introduces a group in which the numbering of parentheses in each
1492            alternative starts with the same number.
1493    
1494        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1495    
1496     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1497        PCRE_INFO_JCHANGED.
1498    
1499     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1500        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1501        for detecting groups that can match an empty string.
1502    
1503     9. A pattern with a very large number of alternatives (more than several
1504        hundred) was running out of internal workspace during the pre-compile
1505        phase, where pcre_compile() figures out how much memory will be needed. A
1506        bit of new cunning has reduced the workspace needed for groups with
1507        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1508        workspace instead of running out of the 4096 that are available.
1509    
1510    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1511    
1512    11. Applied patch from Google to remove an optimization that didn't quite work.
1513        The report of the bug said:
1514    
1515          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1516          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1517          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1518    
1519    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1520        it matched the wrong number of bytes.
1521    
1522    
1523    Version 7.1 24-Apr-07
1524    ---------------------
1525    
1526     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1527        that is more "standard", making use of automake and other Autotools. There
1528        is some re-arrangement of the files and adjustment of comments consequent
1529        on this.
1530    
1531     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1532        for recursive directory scanning broke on some systems because the files
1533        are not scanned in any specific order and on different systems the order
1534        was different. A call to "sort" has been inserted into RunGrepTest for the
1535        approprate test as a short-term fix. In the longer term there may be an
1536        alternative.
1537    
1538     3. I had an email from Eric Raymond about problems translating some of PCRE's
1539        man pages to HTML (despite the fact that I distribute HTML pages, some
1540        people do their own conversions for various reasons). The problems
1541        concerned the use of low-level troff macros .br and .in. I have therefore
1542        removed all such uses from the man pages (some were redundant, some could
1543        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1544        HTML has been updated to handle .nf/.fi and to complain if it encounters
1545        .br or .in.
1546    
1547     4. Updated comments in configure.ac that get placed in config.h.in and also
1548        arranged for config.h to be included in the distribution, with the name
1549        config.h.generic, for the benefit of those who have to compile without
1550        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1551    
1552     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1553        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1554        makevp.bat for the current PCRE, using the additional files
1555        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1556    
1557     6. A Windows user reported a minor discrepancy with test 2, which turned out
1558        to be caused by a trailing space on an input line that had got lost in his
1559        copy. The trailing space was an accident, so I've just removed it.
1560    
1561     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1562        that is needed.
1563    
1564     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1565        as "const" (a) because they are and (b) because it helps the PHP
1566        maintainers who have recently made a script to detect big data structures
1567        in the php code that should be moved to the .rodata section. I remembered
1568        to update Builducptable as well, so it won't revert if ucptable.h is ever
1569        re-created.
1570    
1571     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1572        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1573        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1574        support is not required. This saves 1.5-2K of code, which is important in
1575        some applications.
1576    
1577        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1578        so as not to refer to the tables, even though these functions will never be
1579        called when UTF-8 support is disabled. Otherwise there are problems with a
1580        shared library.
1581    
1582    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1583    
1584        (a) It was defining its arguments as char * instead of void *.
1585    
1586        (b) It was assuming that all moves were upwards in memory; this was true
1587            a long time ago when I wrote it, but is no longer the case.
1588    
1589        The emulated memove() is provided for those environments that have neither
1590        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1591        is clearly not the case, as these two bugs were recently reported.
1592    
1593    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1594        and Detrail to create the HTML documentation, the .txt form of the man
1595        pages, and it removes trailing spaces from listed files. It also creates
1596        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1597        case, it wraps all the #defines with #ifndefs. This script should be run
1598        before "make dist".
1599    
1600    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1601        with Unicode property support.
1602    
1603        (a) For a maximizing quantifier, if the two different cases of the
1604            character were of different lengths in their UTF-8 codings (there are
1605            some cases like this - I found 11), and the matching function had to
1606            back up over a mixture of the two cases, it incorrectly assumed they
1607            were both the same length.
1608    
1609        (b) When PCRE was configured to use the heap rather than the stack for
1610            recursion during matching, it was not correctly preserving the data for
1611            the other case of a UTF-8 character when checking ahead for a match
1612            while processing a minimizing repeat. If the check also involved
1613            matching a wide character, but failed, corruption could cause an
1614            erroneous result when trying to check for a repeat of the original
1615            character.
1616    
1617    13. Some tidying changes to the testing mechanism:
1618    
1619        (a) The RunTest script now detects the internal link size and whether there
1620            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1621            values substituted by "configure". (The RunGrepTest script already did
1622            this for UTF-8.) The configure.ac script no longer substitutes the
1623            relevant variables.
1624    
1625        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1626            with length and offset values. This means that the output is different
1627            for different internal link sizes. Test 2 is skipped for link sizes
1628            other than 2 because of this, bypassing the problem. Unfortunately,
1629            there was also a test in test 3 (the locale tests) that used /B and
1630            failed for link sizes other than 2. Rather than cut the whole test out,
1631            I have added a new /Z option to pcretest that replaces the length and
1632            offset values with spaces. This is now used to make test 3 independent
1633            of link size. (Test 2 will be tidied up later.)
1634    
1635    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1636        segmentation fault instead of returning the appropriate error message.
1637    
1638    15. In multiline mode when the newline sequence was set to "any", the pattern
1639        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1640        This doesn't seem right; it now treats the CRLF combination as the line
1641        ending, and so does not match in that case. It's only a pattern such as ^$
1642        that would hit this one: something like ^ABC$ would have failed after \r
1643        and then tried again after \r\n.
1644    
1645    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1646        in an attempt to make files that differ only in their line terminators
1647        compare equal. This works on Linux.
1648    
1649    17. Under certain error circumstances pcregrep might try to free random memory
1650        as it exited. This is now fixed, thanks to valgrind.
1651    
1652    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1653        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1654        was because its rules for how to advance for /g after matching an empty
1655        string at the end of a line did not allow for this case. They now check for
1656        it specially.
1657    
1658    20. pcretest is supposed to handle patterns and data of any length, by
1659        extending its buffers when necessary. It was getting this wrong when the
1660        buffer for a data line had to be extended.
1661    
1662    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1663        CRLF as a newline sequence.
1664    
1665    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1666        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1667        I have nevertheless tidied it up.
1668    
1669    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1670    
1671    24. Added a man page for pcre-config.
1672    
1673    
1674    Version 7.0 19-Dec-06
1675    ---------------------
1676    
1677     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1678        moving to gcc 4.1.1.
1679    
1680     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1681        sys/time.h, which is documented as needed for this function. It doesn't
1682        seem to matter on Linux, but it showed up on some releases of OS X.
1683    
1684     3. It seems that there are systems where bytes whose values are greater than
1685        127 match isprint() in the "C" locale. The "C" locale should be the
1686        default when a C program starts up. In most systems, only ASCII printing
1687        characters match isprint(). This difference caused the output from pcretest
1688        to vary, making some of the tests fail. I have changed pcretest so that:
1689    
1690        (a) When it is outputting text in the compiled version of a pattern, bytes
1691            other than 32-126 are always shown as hex escapes.
1692    
1693        (b) When it is outputting text that is a matched part of a subject string,
1694            it does the same, unless a different locale has been set for the match
1695            (using the /L modifier). In this case, it uses isprint() to decide.
1696    
1697     4. Fixed a major bug that caused incorrect computation of the amount of memory
1698        required for a compiled pattern when options that changed within the
1699        pattern affected the logic of the preliminary scan that determines the
1700        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1701        that the computed length was too small. The symptoms of this bug were
1702        either the PCRE error "internal error: code overflow" from pcre_compile(),
1703        or a glibc crash with a message such as "pcretest: free(): invalid next
1704        size (fast)". Examples of patterns that provoked this bug (shown in
1705        pcretest format) are:
1706    
1707          /(?-x: )/x
1708          /(?x)(?-x: \s*#\s*)/
1709          /((?i)[\x{c0}])/8
1710          /(?i:[\x{c0}])/8
1711    
1712        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1713        is now done differently.
1714    
1715     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1716        wrapper classes; (b) implement a new function in the C++ scanner that is
1717        more efficient than the old way of doing things because it avoids levels of
1718        recursion in the regex matching; (c) add a paragraph to the documentation
1719        for the FullMatch() function.
1720    
1721     6. The escape sequence \n was being treated as whatever was defined as
1722        "newline". Not only was this contrary to the documentation, which states
1723        that \n is character 10 (hex 0A), but it also went horribly wrong when
1724        "newline" was defined as CRLF. This has been fixed.
1725    
1726     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1727        was being set to -1 for the "end of line" case (supposedly a value that no
1728        character can have). Though this value is never used (the check for end of
1729        line is "zero bytes in current character"), it caused compiler complaints.
1730        I've changed it to 0xffffffff.
1731    
1732     8. In pcre_version.c, the version string was being built by a sequence of
1733        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1734        string (as it is for production releases) called a macro with an empty
1735        argument. The C standard says the result of this is undefined. The gcc
1736        compiler treats it as an empty string (which was what was wanted) but it is
1737        reported that Visual C gives an error. The source has been hacked around to
1738        avoid this problem.
1739    
1740     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1741        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1742        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1743        of them did).
1744    
1745    10. Originally, pcretest opened its input and output without "b"; then I was
1746        told that "b" was needed in some environments, so it was added for release
1747        5.0 to both the input and output. (It makes no difference on Unix-like
1748        systems.) Later I was told that it is wrong for the input on Windows. I've
1749        now abstracted the modes into two macros, to make it easier to fiddle with
1750        them, and removed "b" from the input mode under Windows.
1751    
1752    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1753    
1754    12. Added -help and --help to pcretest as an official way of being reminded
1755        of the options.
1756    
1757    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1758        and pcrecpp.cc because they annoy compilers at high warning levels.
1759    
1760    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1761    
1762    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1763        scripts are not C programs :-) and which was not noticed because it works
1764        on Linux.
1765    
1766    16. pcretest is supposed to handle any length of pattern and data line (as one
1767        line or as a continued sequence of lines) by extending its input buffer if
1768        necessary. This feature was broken for very long pattern lines, leading to
1769        a string of junk being passed to pcre_compile() if the pattern was longer
1770        than about 50K.
1771    
1772    17. I have done a major re-factoring of the way pcre_compile() computes the
1773        amount of memory needed for a compiled pattern. Previously, there was code
1774        that made a preliminary scan of the pattern in order to do this. That was
1775        OK when PCRE was new, but as the facilities have expanded, it has become
1776        harder and harder to keep it in step with the real compile phase, and there
1777        have been a number of bugs (see for example, 4 above). I have now found a
1778        cunning way of running the real compile function in a "fake" mode that
1779        enables it to compute how much memory it would need, while actually only
1780        ever using a few hundred bytes of working memory and without too many
1781        tests of the mode. This should make future maintenance and development
1782        easier. A side effect of this work is that the limit of 200 on the nesting
1783        depth of parentheses has been removed (though this was never a serious
1784        limitation, I suspect). However, there is a downside: pcre_compile() now
1785        runs more slowly than before (30% or more, depending on the pattern). I
1786        hope this isn't a big issue. There is no effect on runtime performance.
1787    
1788    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1789        newline (only possible for the last line of a file) and it was a
1790        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1791    
1792    19. Added additional timing features to pcretest. (1) The -tm option now times
1793        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1794        separate command line item, by a number that specifies the number of
1795        repeats to use when timing. The default is 50000; this gives better
1796        precision, but takes uncomfortably long for very large patterns.
1797    
1798    20. Extended pcre_study() to be more clever in cases where a branch of a
1799        subpattern has no definite first character. For example, (a*|b*)[cd] would
1800        previously give no result from pcre_study(). Now it recognizes that the
1801        first character must be a, b, c, or d.
1802    
1803    21. There was an incorrect error "recursive call could loop indefinitely" if
1804        a subpattern (or the entire pattern) that was being tested for matching an
1805        empty string contained only one non-empty item after a nested subpattern.
1806        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1807        incorrectly, because the \d was being skipped in the check.
1808    
1809    22. The pcretest program now has a new pattern option /B and a command line
1810        option -b, which is equivalent to adding /B to every pattern. This causes
1811        it to show the compiled bytecode, without the additional information that
1812        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1813        is the same as /B/I).
1814    
1815    23. A new optimization is now able automatically to treat some sequences such
1816        as a*b as a*+b. More specifically, if something simple (such as a character
1817        or a simple class like \d) has an unlimited quantifier, and is followed by
1818        something that cannot possibly match the quantified thing, the quantifier
1819        is automatically "possessified".
1820    
1821    24. A recursive reference to a subpattern whose number was greater than 39
1822        went wrong under certain circumstances in UTF-8 mode. This bug could also
1823        have affected the operation of pcre_study().
1824    
1825    25. Realized that a little bit of performance could be had by replacing
1826        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1827    
1828    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1829    
1830    27. Possessive quantifiers such as a++ were previously implemented by turning
1831        them into atomic groups such as ($>a+). Now they have their own opcodes,
1832        which improves performance. This includes the automatically created ones
1833        from 23 above.
1834    
1835    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1836        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1837        the first matched character to be a colon. This applied both to named and
1838        numbered groups.
1839    
1840    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1841    
1842    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1843        building PCRE on Windows easier, so I have included it in the distribution.
1844    
1845    31. There is now a check in pcretest against a ridiculously large number being
1846        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1847        loop, the loop is abandoned.
1848    
1849    32. Forward references to subpatterns in conditions such as (?(2)...) where
1850        subpattern 2 is defined later cause pcre_compile() to search forwards in
1851        the pattern for the relevant set of parentheses. This search went wrong
1852        when there were unescaped parentheses in a character class, parentheses
1853        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1854    
1855    33. "Subroutine" calls and backreferences were previously restricted to
1856        referencing subpatterns earlier in the regex. This restriction has now
1857        been removed.
1858    
1859    34. Added a number of extra features that are going to be in Perl 5.10. On the
1860        whole, these are just syntactic alternatives for features that PCRE had
1861        previously implemented using the Python syntax or my own invention. The
1862        other formats are all retained for compatibility.
1863    
1864        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1865            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1866            also .NET compatible.
1867    
1868        (b) A recursion or subroutine call to a named group can now be defined as
1869            (?&name) as well as (?P>name).
1870    
1871        (c) A backreference to a named group can now be defined as \k<name> or
1872            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1873            5.10, are also .NET compatible.
1874    
1875        (d) A conditional reference to a named group can now use the syntax
1876            (?(<name>) or (?('name') as well as (?(name).
1877    
1878        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1879            groups (named and numbered) that are never evaluated inline, but can be
1880            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1881            is always false. There may be only one alternative in such a group.
1882    
1883        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1884            as the simple (?(R). The condition is true only if the most recent
1885            recursion is that of the given number or name. It does not search out
1886            through the entire recursion stack.
1887    
1888        (g) The escape \gN or \g{N} has been added, where N is a positive or
1889            negative number, specifying an absolute or relative reference.
1890    
1891    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1892        some "unreachable code" warnings.
1893    
1894    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1895        things, this adds five new scripts.
1896    
1897    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1898        There were also incompatibilities regarding the handling of \Q..\E inside
1899        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1900        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1901    
1902    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1903        matches an empty string, and forcibly breaks the loop. There were bugs in
1904        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1905        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1906        separate and independent bugs (that affected different cases) have been
1907        fixed.
1908    
1909    39. Refactored the code to abolish the use of different opcodes for small
1910        capturing bracket numbers. This is a tidy that I avoided doing when I
1911        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1912        The new approach is not only tidier, it makes it possible to reduce the
1913        memory needed to fix the previous bug (38).
1914    
1915    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1916        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1917        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1918        mode.
1919    
1920    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1921        report.
1922    
1923    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1924        copy construction and assignment in the C++ wrapper.
1925    
1926    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1927        couple of bugs that could have given wrong results in the "--newline=crlf"
1928        case.
1929    
1930    44. Added a number of casts and did some reorganization of signed/unsigned int
1931        variables following suggestions from Dair Grant. Also renamed the variable
1932        "this" as "item" because it is a C++ keyword.
1933    
1934    45. Arranged for dftables to add
1935    
1936          #include "pcre_internal.h"
1937    
1938        to pcre_chartables.c because without it, gcc 4.x may remove the array
1939        definition from the final binary if PCRE is built into a static library and
1940        dead code stripping is activated.
1941    
1942    46. For an unanchored pattern, if a match attempt fails at the start of a
1943        newline sequence, and the newline setting is CRLF or ANY, and the next two
1944        characters are CRLF, advance by two characters instead of one.
1945    
1946    
1947    Version 6.7 04-Jul-06
1948    ---------------------
1949    
1950     1. In order to handle tests when input lines are enormously long, pcretest has
1951        been re-factored so that it automatically extends its buffers when
1952        necessary. The code is crude, but this _is_ just a test program. The
1953        default size has been increased from 32K to 50K.
1954    
1955     2. The code in pcre_study() was using the value of the re argument before
1956        testing it for NULL. (Of course, in any sensible call of the function, it
1957        won't be NULL.)
1958    
1959     3. The memmove() emulation function in pcre_internal.h, which is used on
1960        systems that lack both memmove() and bcopy() - that is, hardly ever -
1961        was missing a "static" storage class specifier.
1962    
1963     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1964        containing an extended class (one that cannot be represented by a bitmap
1965        because it contains high-valued characters or Unicode property items, e.g.
1966        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1967        pattern, but PCRE should not loop if you do not (it no longer does).
1968        [Detail: two cases were found: (a) a repeated subpattern containing an
1969        extended class; (b) a recursive reference to a subpattern that followed a
1970        previous extended class. It wasn't skipping over the extended class
1971        correctly when UTF-8 mode was not set.]
1972    
1973     5. A negated single-character class was not being recognized as fixed-length
1974        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1975        compile error "lookbehind assertion is not fixed length".
1976    
1977     6. The RunPerlTest auxiliary script was showing an unexpected difference
1978        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1979        write a Perl script that can interpret lines of an input file either as
1980        byte characters or as UTF-8, which is what "perltest" was being required to
1981        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1982        can't do is switch easily at run time between having the "use utf8;" pragma
1983        or not. In the end, I fudged it by using the RunPerlTest script to insert
1984        "use utf8;" explicitly for the UTF-8 tests.
1985    
1986     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1987        the end of the subject string, contrary to the documentation and to what
1988        Perl does. This was true of both matching functions. Now it matches only at
1989        the start of the subject and immediately after *internal* newlines.
1990    
1991     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1992        a pointer to an int instead of a pointer to an unsigned long int. This
1993        caused problems on 64-bit systems.
1994    
1995     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1996        instance of the 'standard' template library not being so standard".
1997    
1998    10. There was no check on the number of named subpatterns nor the maximum
1999        length of a subpattern name. The product of these values is used to compute
2000        the size of the memory block for a compiled pattern. By supplying a very
2001        long subpattern name and a large number of named subpatterns, the size
2002        computation could be caused to overflow. This is now prevented by limiting
2003        the length of names to 32 characters, and the number of named subpatterns
2004        to 10,000.
2005    
2006    11. Subpatterns that are repeated with specific counts have to be replicated in
2007        the compiled pattern. The size of memory for this was computed from the
2008        length of the subpattern and the repeat count. The latter is limited to
2009        65535, but there was no limit on the former, meaning that integer overflow
2010        could in principle occur. The compiled length of a repeated subpattern is
2011        now limited to 30,000 bytes in order to prevent this.
2012    
2013    12. Added the optional facility to have named substrings with the same name.
2014    
2015    13. Added the ability to use a named substring as a condition, using the
2016        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2017        are numbers (not recommended). Forward references are permitted.
2018    
2019    14. Added forward references in named backreferences (if you see what I mean).
2020    
2021    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2022        pattern could run off the end of the subject. For example, the pattern
2023        "(?s)(.{1,5})"8 did this with the subject "ab".
2024    
2025    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2026        PCRE_CASELESS was set when matching characters that were quantified with ?
2027        or *.
2028    
2029    17. A character class other than a single negated character that had a minimum
2030        but no maximum quantifier - for example [ab]{6,} - was not handled
2031        correctly by pce_dfa_exec(). It would match only one character.
2032    
2033    18. A valid (though odd) pattern that looked like a POSIX character
2034        class but used an invalid character after [ (for example [[,abc,]]) caused
2035        pcre_compile() to give the error "Failed: internal error: code overflow" or
2036        in some cases to crash with a glibc free() error. This could even happen if
2037        the pattern terminated after [[ but there just happened to be a sequence of
2038        letters, a binary zero, and a closing ] in the memory that followed.
2039    
2040    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2041        over the years. Originally (before any Unicode support), just the bottom 8
2042        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2043        output from "man perlunicode" includes this:
2044    
2045          The regular expression compiler produces polymorphic opcodes.  That
2046          is, the pattern adapts to the data and automatically switches to
2047          the Unicode character scheme when presented with Unicode data--or
2048          instead uses a traditional byte scheme when presented with byte
2049          data.
2050    
2051        Sadly, a wide octal escape does not cause a switch, and in a string with
2052        no other multibyte characters, these octal escapes are treated as before.
2053        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2054        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2055        Unicode string.
2056    
2057        I have not perpetrated such confusion in PCRE. Up till now, it took just
2058        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2059        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2060        translate to the appropriate multibyte character.
2061    
2062    29. Applied some refactoring to reduce the number of warnings from Microsoft
2063        and Borland compilers. This has included removing the fudge introduced
2064        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2065        a warning about an unused variable.
2066    
2067    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2068        characters since release 4.0, because Perl (from release 5.004) does not.
2069        [Or at least, is documented not to: some releases seem to be in conflict
2070        with the documentation.] However, when a pattern was studied with
2071        pcre_study() and all its branches started with \s, PCRE still included VT
2072        as a possible starting character. Of course, this did no harm; it just
2073        caused an unnecessary match attempt.
2074    
2075    22. Removed a now-redundant internal flag bit that recorded the fact that case
2076        dependency changed within the pattern. This was once needed for "required
2077        byte" processing, but is no longer used. This recovers a now-scarce options
2078        bit. Also moved the least significant internal flag bit to the most-
2079        significant bit of the word, which was not previously used (hangover from
2080        the days when it was an int rather than a uint) to free up another bit for
2081        the future.
2082    
2083    23. Added support for CRLF line endings as well as CR and LF. As well as the
2084        default being selectable at build time, it can now be changed at runtime
2085        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2086        specify that it is scanning data with non-default line endings.
2087    
2088    24. Changed the definition of CXXLINK to make it agree with the definition of
2089        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2090    
2091    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2092        recursions. This makes a big different to stack usage for some patterns.
2093    
2094    26. If a subpattern containing a named recursion or subroutine reference such
2095        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2096        the space required for the compiled pattern went wrong and gave too small a
2097        value. Depending on the environment, this could lead to "Failed: internal
2098        error: code overflow at offset 49" or "glibc detected double free or
2099        corruption" errors.
2100    
2101    27. Applied patches from Google (a) to support the new newline modes and (b) to
2102        advance over multibyte UTF-8 characters in GlobalReplace.
2103    
2104    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2105        difference for some implementation of PCRE in some Windows version.
2106    
2107    29. Added some extra testing facilities to pcretest:
2108    
2109        \q<number>   in a data line sets the "match limit" value
2110        \Q<number>   in a data line sets the "match recursion limt" value
2111        -S <number>  sets the stack size, where <number> is in megabytes
2112    
2113        The -S option isn't available for Windows.
2114    
2115    
2116  Version 6.6 06-Feb-06  Version 6.6 06-Feb-06
2117  ---------------------  ---------------------
2118    

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