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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  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 collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
86    
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
90    
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
95    
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
102    
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
106    
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
109    
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
113    
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
116    
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
125    
126    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127        subject after a captured substring (to make it easier to tell which of a
128        number of identical substrings has been captured).
129    
130    24. The way atomic groups are processed by pcre_exec() has been changed so that
131        if they are repeated, backtracking one repetition now resets captured
132        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134        "aaa". Previously, it would have been "a". As part of this code
135        refactoring, the way recursive calls are handled has also been changed.
136    
137    24. If an assertion condition captured any substrings, they were not passed
138        back unless some other capturing happened later. For example, if
139        (?(?=(a))a) was matched against "a", no capturing was returned.
140    
141    25. When studying a pattern that contained subroutine calls or assertions,
142        the code for finding the minimum length of a possible match was handling
143        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
144        group 1 called group 2 while simultaneously a separate group 2 called group
145        1). A stack overflow occurred in this case. I have fixed this by limiting
146        the recursion depth to 10.
147    
148    26. Updated RunTest.bat in the distribution to the version supplied by Tom
149        Fortmann. This supports explicit test numbers on the command line, and has
150        argument validation and error reporting.
151    
152    27. An instance of \X with an unlimited repeat could fail if at any point the
153        first character it looked at was a mark character.
154    
155    28. Some minor code refactoring concerning Unicode properties and scripts
156        should reduce the stack requirement of match() slightly.
157    
158    29. Added the '=' option to pcretest to check the setting of unused capturing
159        slots at the end of the pattern, which are documented as being -1, but are
160        not included in the return count.
161    
162    30. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
163        compiled something random. Now it gives a compile-time error (as does
164        Perl).
165    
166    31. A *MARK encountered during the processing of a positive assertion is now
167        recorded and passed back (compatible with Perl).
168    
169    32. If --only-matching or --colour was set on a pcregrep call whose pattern
170        had alternative anchored branches, the search for a second match in a line
171        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
172        matched the line "0102" twice. The same bug affected patterns that started
173        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
174        twice.
175    
176    33. Previously, PCRE did not allow quantification of assertions. However, Perl
177        does, and because of capturing effects, quantifying parenthesized
178        assertions may at times be useful. Quantifiers are now allowed for
179        parenthesized assertions.
180    
181    34. A minor code tidy in pcre_compile() when checking options for \R usage.
182    
183    35. \g was being checked for fancy things in a character class, when it should
184        just be a literal "g".
185    
186    36. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
187        appearance of a nested POSIX class supersedes an apparent external class.
188        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
189        unescaped square brackets may also appear as part of class names. For
190        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
191        more like Perl.
192    
193    37. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
194        was because it thought it was \N{name}, which is not supported).
195    
196    38. Add minix to OS list not supporting the -S option in pcretest.
197    
198    39. PCRE tries to detect cases of infinite recursion at compile time, but it
199        cannot analyze patterns in sufficient detail to catch mutual recursions
200        such as ((?1))((?2)). There is now a runtime test that gives an error if a
201        subgroup is called recursively as a subpattern for a second time at the
202        same position in the subject string. In previous releases this might have
203        been caught by the recursion limit, or it might have run out of stack.
204    
205    40. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
206        happen only once. PCRE was, however incorrectly giving a compile time error
207        "recursive call could loop indefinitely" because it cannot analyze the
208        pattern in sufficient detail. The compile time test no longer happens when
209        PCRE is compiling a conditional subpattern, but actual runaway loops are
210        now caught at runtime (see 39 above).
211    
212    41. It seems that Perl allows any characters other than a closing parenthesis
213        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
214        has been changed to be the same.
215    
216    
217    Version 8.12 15-Jan-2011
218    ------------------------
219    
220    1.  Fixed some typos in the markup of the man pages, and wrote a script that
221        checks for such things as part of the documentation building process.
222    
223    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
224        --match-limit and --recursion-limit options (added for 8.11). In
225        particular, this made one of the standard tests fail. (The integer value
226        went into the wrong half of a long int.)
227    
228    3.  If the --colour option was given to pcregrep with -v (invert match), it
229        did strange things, either producing crazy output, or crashing. It should,
230        of course, ignore a request for colour when reporting lines that do not
231        match.
232    
233    4.  Another pcregrep bug caused similar problems if --colour was specified with
234        -M (multiline) and the pattern match finished with a line ending.
235    
236    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
237        matched in multiline mode, the following line was shown as part of the
238        match. This seems wrong, so I have changed it.
239    
240    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
241        the check for further matches in the same line (so they could be coloured)
242        to overrun the end of the current line. If another match was found, it was
243        incorrectly shown (and then shown again when found in the next line).
244    
245    7.  If pcregrep was compiled under Windows, there was a reference to the
246        function pcregrep_exit() before it was defined. I am assuming this was
247        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
248        reported by a user. I've moved the definition above the reference.
249    
250    
251    Version 8.11 10-Dec-2010
252    ------------------------
253    
254    1.  (*THEN) was not working properly if there were untried alternatives prior
255        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
256        backtracked to try for "b" instead of moving to the next alternative branch
257        at the same level (in this case, to look for "c"). The Perl documentation
258        is clear that when (*THEN) is backtracked onto, it goes to the "next
259        alternative in the innermost enclosing group".
260    
261    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
262        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
263        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
264        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
265        (*THEN).
266    
267    3.  If \s appeared in a character class, it removed the VT character from
268        the class, even if it had been included by some previous item, for example
269        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
270        of \s, but is part of the POSIX "space" class.)
271    
272    4.  A partial match never returns an empty string (because you can always
273        match an empty string at the end of the subject); however the checking for
274        an empty string was starting at the "start of match" point. This has been
275        changed to the "earliest inspected character" point, because the returned
276        data for a partial match starts at this character. This means that, for
277        example, /(?<=abc)def/ gives a partial match for the subject "abc"
278        (previously it gave "no match").
279    
280    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
281        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
282        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
283        has an implication that the given string is incomplete (because a partial
284        match is preferred over a full match). For this reason, these items now
285        give a partial match in this situation. [Aside: previously, the one case
286        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
287        match rather than a full match, which was wrong by the old rules, but is
288        now correct.]
289    
290    6.  There was a bug in the handling of #-introduced comments, recognized when
291        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
292        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
293        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
294        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
295        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
296        places in pcre_compile().
297    
298    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
299        comments when looking ahead for named forward references to subpatterns,
300        the only newline sequence it recognized was NL. It now handles newlines
301        according to the set newline convention.
302    
303    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
304        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
305        cater for a lack of strerror(). These oversights have been fixed.
306    
307    9.  Added --match-limit and --recursion-limit to pcregrep.
308    
309    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
310    
311    11. When the -o option was used, pcregrep was setting a return code of 1, even
312        when matches were found, and --line-buffered was not being honoured.
313    
314    12. Added an optional parentheses number to the -o and --only-matching options
315        of pcregrep.
316    
317    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
318        can match an empty string. The code to do it in pcretest and pcredemo
319        needed fixing:
320    
321        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
322            only one byte after an empty string match just before CRLF (this case
323            just got forgotten; "any" and "anycrlf" were OK).
324    
325        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
326            mode when an empty string match preceded an ASCII character followed by
327            a non-ASCII character. (The code for advancing by one character rather
328            than one byte was nonsense.)
329    
330        (c) The pcredemo.c sample program did not have any code at all to handle
331            the cases when CRLF is a valid newline sequence.
332    
333    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
334        as a starting offset was within the subject string. There is now a new
335        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
336        negative or greater than the length of the string. In order to test this,
337        pcretest is extended to allow the setting of negative starting offsets.
338    
339    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
340        starting offset points to the beginning of a UTF-8 character was
341        unnecessarily clumsy. I tidied it up.
342    
343    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
344        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
345    
346    17. Nobody had reported that the --include_dir option, which was added in
347        release 7.7 should have been called --include-dir (hyphen, not underscore)
348        for compatibility with GNU grep. I have changed it to --include-dir, but
349        left --include_dir as an undocumented synonym, and the same for
350        --exclude-dir, though that is not available in GNU grep, at least as of
351        release 2.5.4.
352    
353    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
354        characters from a string of bytes) have been redefined so as not to use
355        loops, in order to improve performance in some environments. At the same
356        time, I abstracted some of the common code into auxiliary macros to save
357        repetition (this should not affect the compiled code).
358    
359    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
360        compile-time error is now given if \c is not followed by an ASCII
361        character, that is, a byte less than 128. (In EBCDIC mode, the code is
362        different, and any byte value is allowed.)
363    
364    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
365        START_OPTIMIZE option, which is now allowed at compile time - but just
366        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
367        to pcregrep and other applications that have no direct access to PCRE
368        options. The new /Y option in pcretest sets this option when calling
369        pcre_compile().
370    
371    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
372        back references. Groups containing recursive back references were forced to
373        be atomic by that change, but in the case of named groups, the amount of
374        memory required was incorrectly computed, leading to "Failed: internal
375        error: code overflow". This has been fixed.
376    
377    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
378        pcretest.c, to avoid build problems in some Borland environments.
379    
380    
381    Version 8.10 25-Jun-2010
382    ------------------------
383    
384    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
385        THEN.
386    
387    2.  (*ACCEPT) was not working when inside an atomic group.
388    
389    3.  Inside a character class, \B is treated as a literal by default, but
390        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
391        causes the error). The code is unchanged, but I tidied the documentation.
392    
393    4.  Inside a character class, PCRE always treated \R and \X as literals,
394        whereas Perl faults them if its -w option is set. I have changed PCRE so
395        that it faults them when PCRE_EXTRA is set.
396    
397    5.  Added support for \N, which always matches any character other than
398        newline. (It is the same as "." when PCRE_DOTALL is not set.)
399    
400    6.  When compiling pcregrep with newer versions of gcc which may have
401        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
402        declared with attribute warn_unused_result" were given. Just casting the
403        result to (void) does not stop the warnings; a more elaborate fudge is
404        needed. I've used a macro to implement this.
405    
406    7.  Minor change to pcretest.c to avoid a compiler warning.
407    
408    8.  Added four artifical Unicode properties to help with an option to make
409        \s etc use properties (see next item). The new properties are: Xan
410        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
411    
412    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
413        use Unicode properties. (*UCP) at the start of a pattern can be used to set
414        this option. Modified pcretest to add /W to test this facility. Added
415        REG_UCP to make it available via the POSIX interface.
416    
417    10. Added --line-buffered to pcregrep.
418    
419    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
420        studied, and the match started with a letter with a code point greater than
421        127 whose first byte was different to the first byte of the other case of
422        the letter, the other case of this starting letter was not recognized
423        (#976).
424    
425    12. If a pattern that was studied started with a repeated Unicode property
426        test, for example, \p{Nd}+, there was the theoretical possibility of
427        setting up an incorrect bitmap of starting bytes, but fortunately it could
428        not have actually happened in practice until change 8 above was made (it
429        added property types that matched character-matching opcodes).
430    
431    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
432        possible starting bytes for non-anchored patterns.
433    
434    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
435        \R, and also a number of cases that involve Unicode properties, both
436        explicit and implicit when PCRE_UCP is set.
437    
438    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
439        input, it could crash or give wrong results if characters with values
440        greater than 0xc0 were present in the subject string. (Detail: it assumed
441        UTF-8 input when processing these items.)
442    
443    16. Added a lot of (int) casts to avoid compiler warnings in systems where
444        size_t is 64-bit (#991).
445    
446    17. Added a check for running out of memory when PCRE is compiled with
447        --disable-stack-for-recursion (#990).
448    
449    18. If the last data line in a file for pcretest does not have a newline on
450        the end, a newline was missing in the output.
451    
452    19. The default pcre_chartables.c file recognizes only ASCII characters (values
453        less than 128) in its various bitmaps. However, there is a facility for
454        generating tables according to the current locale when PCRE is compiled. It
455        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
456        characters, are recognized by isspace() and therefore were getting set in
457        these tables, and indeed these tables seem to approximate to ISO 8859. This
458        caused a problem in UTF-8 mode when pcre_study() was used to create a list
459        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
460        which of course cannot start UTF-8 characters. I have changed the code so
461        that only real ASCII characters (less than 128) and the correct starting
462        bytes for UTF-8 encodings are set for characters greater than 127 when in
463        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
464        altogether.)
465    
466    20. Added the /T option to pcretest so as to be able to run tests with non-
467        standard character tables, thus making it possible to include the tests
468        used for 19 above in the standard set of tests.
469    
470    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
471        reference to a subpattern the other side of a comment that contains an
472        opening parenthesis caused either an internal compiling error, or a
473        reference to the wrong subpattern.
474    
475    
476    Version 8.02 19-Mar-2010
477    ------------------------
478    
479    1.  The Unicode data tables have been updated to Unicode 5.2.0.
480    
481    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
482        configured.
483    
484    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
485        original author of that file, following a query about its status.
486    
487    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
488        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
489    
490    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
491        quantifier applied to a forward-referencing subroutine call, could compile
492        incorrect code or give the error "internal error: previously-checked
493        referenced subpattern not found".
494    
495    6.  Both MS Visual Studio and Symbian OS have problems with initializing
496        variables to point to external functions. For these systems, therefore,
497        pcre_malloc etc. are now initialized to local functions that call the
498        relevant global functions.
499    
500    7.  There were two entries missing in the vectors called coptable and poptable
501        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
502        I've fixed the data, and added a kludgy way of testing at compile time that
503        the lengths are correct (equal to the number of opcodes).
504    
505    8.  Following on from 7, I added a similar kludge to check the length of the
506        eint vector in pcreposix.c.
507    
508    9.  Error texts for pcre_compile() are held as one long string to avoid too
509        much relocation at load time. To find a text, the string is searched,
510        counting zeros. There was no check for running off the end of the string,
511        which could happen if a new error number was added without updating the
512        string.
513    
514    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
515    
516    11. \K was not working if it appeared in an atomic group or in a group that
517        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
518        \K is "not well defined" if used in an assertion. PCRE now accepts it if
519        the assertion is positive, but not if it is negative.
520    
521    12. Change 11 fortuitously reduced the size of the stack frame used in the
522        "match()" function of pcre_exec.c by one pointer. Forthcoming
523        implementation of support for (*MARK) will need an extra pointer on the
524        stack; I have reserved it now, so that the stack frame size does not
525        decrease.
526    
527    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
528        item in branch that calls a recursion is a subroutine call - as in the
529        second branch in the above example - was incorrectly given the compile-
530        time error "recursive call could loop indefinitely" because pcre_compile()
531        was not correctly checking the subroutine for matching a non-empty string.
532    
533    14. The checks for overrunning compiling workspace could trigger after an
534        overrun had occurred. This is a "should never occur" error, but it can be
535        triggered by pathological patterns such as hundreds of nested parentheses.
536        The checks now trigger 100 bytes before the end of the workspace.
537    
538    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
539    
540    
541    Version 8.01 19-Jan-2010
542    ------------------------
543    
544    1.  If a pattern contained a conditional subpattern with only one branch (in
545        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
546        computed the wrong minimum data length (which is of course zero for such
547        subpatterns). This could cause incorrect "no match" results.
548    
549    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
550        the pattern is reset in the first branch, pcre_compile() failed with
551        "internal error: code overflow at offset...". This happened only when
552        the reset was to the original external option setting. (An optimization
553        abstracts leading options settings into an external setting, which was the
554        cause of this.)
555    
556    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
557        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
558        assertion pattern did not match (meaning that the assertion was true), it
559        was incorrectly treated as false if the SKIP had been reached during the
560        matching. This also applied to assertions used as conditions.
561    
562    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
563        assertion subpattern, including such a pattern used as a condition,
564        unpredictable results occurred, instead of the error return
565        PCRE_ERROR_DFA_UITEM.
566    
567    5.  The C++ GlobalReplace function was not working like Perl for the special
568        situation when an empty string is matched. It now does the fancy magic
569        stuff that is necessary.
570    
571    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
572        removed. (These were left over from very, very early versions of PCRE.)
573    
574    7.  Some cosmetic changes to the code to make life easier when compiling it
575        as part of something else:
576    
577        (a) Change DEBUG to PCRE_DEBUG.
578    
579        (b) In pcre_compile(), rename the member of the "branch_chain" structure
580            called "current" as "current_branch", to prevent a collision with the
581            Linux macro when compiled as a kernel module.
582    
583        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
584            prevent a collision with the Linux macro when compiled as a kernel
585            module.
586    
587    8.  In pcre_compile() there are some checks for integer overflows that used to
588        cast potentially large values to (double). This has been changed to that
589        when building, a check for int64_t is made, and if it is found, it is used
590        instead, thus avoiding the use of floating point arithmetic. (There is no
591        other use of FP in PCRE.) If int64_t is not found, the fallback is to
592        double.
593    
594    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
595        2005 (difference between two addresses compared to an unsigned value).
596    
597    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
598        custom one, because of the following reported problem in Windows:
599    
600          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
601              under Win32.
602          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
603              therefore missing the function definition.
604          - The compiler thus generates a "C" signature for the test function.
605          - The linker fails to find the "C" function.
606          - PCRE fails to configure if asked to do so against libbz2.
607    
608    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
609        messages were output:
610    
611          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
612          rerunning libtoolize, to keep the correct libtool macros in-tree.
613          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
614    
615        I have done both of these things.
616    
617    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
618        most of the time, it *can* run out if it is given a pattern that contains a
619        runaway infinite recursion. I updated the discussion in the pcrestack man
620        page.
621    
622    13. Now that we have gone to the x.xx style of version numbers, the minor
623        version may start with zero. Using 08 or 09 is a bad idea because users
624        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
625        interpreted as invalid octal numbers. I've updated the previous comment in
626        configure.ac, and also added a check that gives an error if 08 or 09 are
627        used.
628    
629    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
630        causing partial matching to fail when the end of the subject matched \W
631        in a UTF-8 pattern where \W was quantified with a minimum of 3.
632    
633    15. There were some discrepancies between the declarations in pcre_internal.h
634        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
635        their definitions. The declarations used "const uschar *" and the
636        definitions used USPTR. Even though USPTR is normally defined as "const
637        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
638        reported that: "This difference in casting confuses some C++ compilers, for
639        example, SunCC recognizes above declarations as different functions and
640        generates broken code for hbpcre." I have changed the declarations to use
641        USPTR.
642    
643    16. GNU libtool is named differently on some systems. The autogen.sh script now
644        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
645        (FreeBSD).
646    
647    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
648        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
649        comment: "Figure out how to create a longlong from a string: strtoll and
650        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
651        instance, but it only takes 2 args instead of 3!"
652    
653    18. A subtle bug concerned with back references has been fixed by a change of
654        specification, with a corresponding code fix. A pattern such as
655        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
656        refers, was giving matches when it shouldn't. For example, xa=xaaa would
657        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
658        same bug. Such groups have to be quantified to be useful, or contained
659        inside another quantified group. (If there's no repetition, the reference
660        can never match.) The problem arises because, having left the group and
661        moved on to the rest of the pattern, a later failure that backtracks into
662        the group uses the captured value from the final iteration of the group
663        rather than the correct earlier one. I have fixed this in PCRE by forcing
664        any group that contains a reference to itself to be an atomic group; that
665        is, there cannot be any backtracking into it once it has completed. This is
666        similar to recursive and subroutine calls.
667    
668    
669    Version 8.00 19-Oct-09
670    ----------------------
671    
672    1.  The table for translating pcre_compile() error codes into POSIX error codes
673        was out-of-date, and there was no check on the pcre_compile() error code
674        being within the table. This could lead to an OK return being given in
675        error.
676    
677    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
678        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
679        in a Windows environment.
680    
681    3.  The pcregrep --count option prints the count for each file even when it is
682        zero, as does GNU grep. However, pcregrep was also printing all files when
683        --files-with-matches was added. Now, when both options are given, it prints
684        counts only for those files that have at least one match. (GNU grep just
685        prints the file name in this circumstance, but including the count seems
686        more useful - otherwise, why use --count?) Also ensured that the
687        combination -clh just lists non-zero counts, with no names.
688    
689    4.  The long form of the pcregrep -F option was incorrectly implemented as
690        --fixed_strings instead of --fixed-strings. This is an incompatible change,
691        but it seems right to fix it, and I didn't think it was worth preserving
692        the old behaviour.
693    
694    5.  The command line items --regex=pattern and --regexp=pattern were not
695        recognized by pcregrep, which required --regex pattern or --regexp pattern
696        (with a space rather than an '='). The man page documented the '=' forms,
697        which are compatible with GNU grep; these now work.
698    
699    6.  No libpcreposix.pc file was created for pkg-config; there was just
700        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
701    
702    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
703        when UCP support is not needed, by modifying the Python script that
704        generates it from Unicode data files. This should not matter if the module
705        is correctly used as a library, but I received one complaint about 50K of
706        unwanted data. My guess is that the person linked everything into his
707        program rather than using a library. Anyway, it does no harm.
708    
709    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
710        was a minimum greater than 1 for a wide character in a possessive
711        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
712        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
713        character. Chaos in the form of incorrect output or a compiling loop could
714        result.
715    
716    9.  The restrictions on what a pattern can contain when partial matching is
717        requested for pcre_exec() have been removed. All patterns can now be
718        partially matched by this function. In addition, if there are at least two
719        slots in the offset vector, the offset of the earliest inspected character
720        for the match and the offset of the end of the subject are set in them when
721        PCRE_ERROR_PARTIAL is returned.
722    
723    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
724        synonymous with PCRE_PARTIAL, for backwards compatibility, and
725        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
726        and may be more useful for multi-segment matching.
727    
728    11. Partial matching with pcre_exec() is now more intuitive. A partial match
729        used to be given if ever the end of the subject was reached; now it is
730        given only if matching could not proceed because another character was
731        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
732        string "Z", which now yields "no match" instead of "partial match". In the
733        case of pcre_dfa_exec(), "no match" is given if every matching path for the
734        final character ended with (*FAIL).
735    
736    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
737        if the pattern had a "must contain" character that was already found in the
738        earlier partial match, unless partial matching was again requested. For
739        example, with the pattern /dog.(body)?/, the "must contain" character is
740        "g". If the first part-match was for the string "dog", restarting with
741        "sbody" failed. This bug has been fixed.
742    
743    13. The string returned by pcre_dfa_exec() after a partial match has been
744        changed so that it starts at the first inspected character rather than the
745        first character of the match. This makes a difference only if the pattern
746        starts with a lookbehind assertion or \b or \B (\K is not supported by
747        pcre_dfa_exec()). It's an incompatible change, but it makes the two
748        matching functions compatible, and I think it's the right thing to do.
749    
750    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
751        so that the demonstration program is easily available in environments where
752        PCRE has not been installed from source.
753    
754    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
755        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
756        library.
757    
758    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
759        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
760        is not the first non-POSIX option to be added. Clearly some people find
761        these options useful.
762    
763    17. If a caller to the POSIX matching function regexec() passes a non-zero
764        value for nmatch with a NULL value for pmatch, the value of
765        nmatch is forced to zero.
766    
767    18. RunGrepTest did not have a test for the availability of the -u option of
768        the diff command, as RunTest does. It now checks in the same way as
769        RunTest, and also checks for the -b option.
770    
771    19. If an odd number of negated classes containing just a single character
772        interposed, within parentheses, between a forward reference to a named
773        subpattern and the definition of the subpattern, compilation crashed with
774        an internal error, complaining that it could not find the referenced
775        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
776        [The bug was that it was starting one character too far in when skipping
777        over the character class, thus treating the ] as data rather than
778        terminating the class. This meant it could skip too much.]
779    
780    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
781        /g option in pcretest when the pattern contains \K, which makes it possible
782        to have an empty string match not at the start, even when the pattern is
783        anchored. Updated pcretest and pcredemo to use this option.
784    
785    21. If the maximum number of capturing subpatterns in a recursion was greater
786        than the maximum at the outer level, the higher number was returned, but
787        with unset values at the outer level. The correct (outer level) value is
788        now given.
789    
790    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
791        PCRE did not set those parentheses (unlike Perl). I have now found a way to
792        make it do so. The string so far is captured, making this feature
793        compatible with Perl.
794    
795    23. The tests have been re-organized, adding tests 11 and 12, to make it
796        possible to check the Perl 5.10 features against Perl 5.10.
797    
798    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
799        pattern matches a fixed length string. PCRE did not allow this; now it
800        does. Neither allows recursion.
801    
802    25. I finally figured out how to implement a request to provide the minimum
803        length of subject string that was needed in order to match a given pattern.
804        (It was back references and recursion that I had previously got hung up
805        on.) This code has now been added to pcre_study(); it finds a lower bound
806        to the length of subject needed. It is not necessarily the greatest lower
807        bound, but using it to avoid searching strings that are too short does give
808        some useful speed-ups. The value is available to calling programs via
809        pcre_fullinfo().
810    
811    26. While implementing 25, I discovered to my embarrassment that pcretest had
812        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
813        study optimizations had never been tested with that matching function.
814        Oops. What is worse, even when it was passed study data, there was a bug in
815        pcre_dfa_exec() that meant it never actually used it. Double oops. There
816        were also very few tests of studied patterns with pcre_dfa_exec().
817    
818    27. If (?| is used to create subpatterns with duplicate numbers, they are now
819        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
820        on the other side of the coin, they are no longer allowed to have different
821        names, because these cannot be distinguished in PCRE, and this has caused
822        confusion. (This is a difference from Perl.)
823    
824    28. When duplicate subpattern names are present (necessarily with different
825        numbers, as required by 27 above), and a test is made by name in a
826        conditional pattern, either for a subpattern having been matched, or for
827        recursion in such a pattern, all the associated numbered subpatterns are
828        tested, and the overall condition is true if the condition is true for any
829        one of them. This is the way Perl works, and is also more like the way
830        testing by number works.
831    
832    
833    Version 7.9 11-Apr-09
834    ---------------------
835    
836    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
837        (pcretest), all targets were linked against these libraries. This included
838        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
839        libraries. This caused unwanted dependencies to be created. This problem
840        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
841        pcretest is linked with readline.
842    
843    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
844        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
845        moved outside it again, because FALSE and TRUE are already defined in AIX,
846        but BOOL is not.
847    
848    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
849        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
850    
851    4.  The pcregrep documentation said spaces were inserted as well as colons (or
852        hyphens) following file names and line numbers when outputting matching
853        lines. This is not true; no spaces are inserted. I have also clarified the
854        wording for the --colour (or --color) option.
855    
856    5.  In pcregrep, when --colour was used with -o, the list of matching strings
857        was not coloured; this is different to GNU grep, so I have changed it to be
858        the same.
859    
860    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
861        each matching line was coloured. Now it goes on to look for further matches
862        of any of the test patterns, which is the same behaviour as GNU grep.
863    
864    7.  A pattern that could match an empty string could cause pcregrep to loop; it
865        doesn't make sense to accept an empty string match in pcregrep, so I have
866        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
867        seems to be how GNU grep behaves.
868    
869    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
870        start or after a newline", because the conditional assertion was not being
871        correctly handled. The rule now is that both the assertion and what follows
872        in the first alternative must satisfy the test.
873    
874    9.  If auto-callout was enabled in a pattern with a conditional group whose
875        condition was an assertion, PCRE could crash during matching, both with
876        pcre_exec() and pcre_dfa_exec().
877    
878    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
879        used for matching.
880    
881    11. Unicode property support in character classes was not working for
882        characters (bytes) greater than 127 when not in UTF-8 mode.
883    
884    12. Added the -M command line option to pcretest.
885    
886    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
887    
888    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
889    
890    16. Added comments and documentation about mis-use of no_arg in the C++
891        wrapper.
892    
893    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
894        from Martin Jerabek that uses macro names for all relevant character and
895        string constants.
896    
897    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
898        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
899        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
900        these, but not everybody uses configure.
901    
902    19. A conditional group that had only one branch was not being correctly
903        recognized as an item that could match an empty string. This meant that an
904        enclosing group might also not be so recognized, causing infinite looping
905        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
906        with the subject "ab", where knowledge that the repeated group can match
907        nothing is needed in order to break the loop.
908    
909    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
910        exec(), but without supplying a callout function, matching went wrong.
911    
912    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
913        leak if the size of the offset vector was greater than 30. When the vector
914        is smaller, the saved offsets during recursion go onto a local stack
915        vector, but for larger vectors malloc() is used. It was failing to free
916        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
917        error, in fact).
918    
919    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
920        heapframe that is used only when UTF-8 support is enabled. This caused no
921        problem, but was untidy.
922    
923    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
924        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
925        included within another project.
926    
927    24. Steven Van Ingelgem's patches to add more options to the CMake support,
928        slightly modified by me:
929    
930          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
931              not building pcregrep.
932    
933          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
934              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
935    
936    25. Forward references, both numeric and by name, in patterns that made use of
937        duplicate group numbers, could behave incorrectly or give incorrect errors,
938        because when scanning forward to find the reference group, PCRE was not
939        taking into account the duplicate group numbers. A pattern such as
940        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
941    
942    26. Changed a few more instances of "const unsigned char *" to USPTR, making
943        the feature of a custom pointer more persuasive (as requested by a user).
944    
945    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
946        pcretest.c, inside #ifndefs, because it seems they are sometimes already
947        pre-defined.
948    
949    28. Added support for (*UTF8) at the start of a pattern.
950    
951    29. Arrange for flags added by the "release type" setting in CMake to be shown
952        in the configuration summary.
953    
954    
955    Version 7.8 05-Sep-08
956    ---------------------
957    
958    1.  Replaced UCP searching code with optimized version as implemented for Ad
959        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
960        stage table and inline lookup instead of a function, giving speed ups of 2
961        to 5 times on some simple patterns that I tested. Permission was given to
962        distribute the MultiStage2.py script that generates the tables (it's not in
963        the tarball, but is in the Subversion repository).
964    
965    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
966        scripts.
967    
968    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
969        a group with a zero qualifier. The result of the study could be incorrect,
970        or the function might crash, depending on the pattern.
971    
972    4.  Caseless matching was not working for non-ASCII characters in back
973        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
974        It now works when Unicode Property Support is available.
975    
976    5.  In pcretest, an escape such as \x{de} in the data was always generating
977        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
978        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
979        truncation.
980    
981    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
982    
983    7.  Added two (int) casts to pcregrep when printing the difference of two
984        pointers, in case they are 64-bit values.
985    
986    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
987        test 2 if it fails.
988    
989    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
990        and a #define of that name to empty if it is not externally set. This is to
991        allow users of MSVC to set it if necessary.
992    
993    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
994        the convenience functions in the pcre_get.c source file.
995    
996    11. An option change at the start of a pattern that had top-level alternatives
997        could cause overwriting and/or a crash. This command provoked a crash in
998        some environments:
999    
1000          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1001    
1002        This potential security problem was recorded as CVE-2008-2371.
1003    
1004    12. For a pattern where the match had to start at the beginning or immediately
1005        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1006        pcre_dfa_exec() could read past the end of the passed subject if there was
1007        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1008        pcretest so that it places the subject at the end of its malloc-ed buffer.
1009    
1010    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1011        exec() might read past the end of the data buffer in UTF-8 mode.
1012    
1013    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1014        the data contained the byte 0x85 as part of a UTF-8 character within its
1015        first line. This applied both to normal and DFA matching.
1016    
1017    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1018        /^[^d]*?$/8 failed to match "abc".
1019    
1020    16. Added a missing copyright notice to pcrecpp_internal.h.
1021    
1022    17. Make it more clear in the documentation that values returned from
1023        pcre_exec() in ovector are byte offsets, not character counts.
1024    
1025    18. Tidied a few places to stop certain compilers from issuing warnings.
1026    
1027    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1028        supplied by Stefan Weber. I made a further small update for 7.8 because
1029        there is a change of source arrangements: the pcre_searchfuncs.c module is
1030        replaced by pcre_ucd.c.
1031    
1032    
1033    Version 7.7 07-May-08
1034    ---------------------
1035    
1036    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1037        a string to a long long, pretend we don't even have a long long." This is
1038        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1039    
1040    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1041        pre-7.6 versions, which defined a global no_arg variable instead of putting
1042        it in the RE class. (See also #8 below.)
1043    
1044    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1045        Lopes.
1046    
1047    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1048    
1049        (1) The include/exclude patterns were being applied to the whole pathnames
1050            of files, instead of just to the final components.
1051    
1052        (2) If there was more than one level of directory, the subdirectories were
1053            skipped unless they satisfied the include/exclude conditions. This is
1054            inconsistent with GNU grep (and could even be seen as contrary to the
1055            pcregrep specification - which I improved to make it absolutely clear).
1056            The action now is always to scan all levels of directory, and just
1057            apply the include/exclude patterns to regular files.
1058    
1059    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1060        --exclude_dir in the tests to avoid scanning .svn directories.
1061    
1062    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1063        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1064        doesn't support NULs in patterns.
1065    
1066    7.  Added some missing "const"s to declarations of static tables in
1067        pcre_compile.c and pcre_dfa_exec.c.
1068    
1069    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1070        caused by fix #2  above. (Subsequently also a second patch to fix the
1071        first patch. And a third patch - this was a messy problem.)
1072    
1073    9.  Applied Craig's patch to remove the use of push_back().
1074    
1075    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1076        matching function regexec().
1077    
1078    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1079        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1080        references. PCRE supports relative numbers with this syntax (I don't think
1081        Oniguruma does).
1082    
1083    12. Previously, a group with a zero repeat such as (...){0} was completely
1084        omitted from the compiled regex. However, this means that if the group
1085        was called as a subroutine from elsewhere in the pattern, things went wrong
1086        (an internal error was given). Such groups are now left in the compiled
1087        pattern, with a new opcode that causes them to be skipped at execution
1088        time.
1089    
1090    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1091        to the way PCRE behaves:
1092    
1093        (a) A lone ] character is dis-allowed (Perl treats it as data).
1094    
1095        (b) A back reference to an unmatched subpattern matches an empty string
1096            (Perl fails the current match path).
1097    
1098        (c) A data ] in a character class must be notated as \] because if the
1099            first data character in a class is ], it defines an empty class. (In
1100            Perl it is not possible to have an empty class.) The empty class []
1101            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1102            The negative empty class [^] matches any one character, independently
1103            of the DOTALL setting.
1104    
1105    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1106        non-existent subpattern following a character class starting with ']' and
1107        containing () gave an internal compiling error instead of "reference to
1108        non-existent subpattern". Fortunately, when the pattern did exist, the
1109        compiled code was correct. (When scanning forwards to check for the
1110        existencd of the subpattern, it was treating the data ']' as terminating
1111        the class, so got the count wrong. When actually compiling, the reference
1112        was subsequently set up correctly.)
1113    
1114    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1115        it was being rejected as not supported by pcre_dfa_exec(), even though
1116        other assertions are supported. I have made pcre_dfa_exec() support
1117        (*FAIL).
1118    
1119    16. The implementation of 13c above involved the invention of a new opcode,
1120        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1121        cannot be changed at match time, I realized I could make a small
1122        improvement to matching performance by compiling OP_ALLANY instead of
1123        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1124        on the OP_ANY path.
1125    
1126    17. Compiling pcretest on Windows with readline support failed without the
1127        following two fixes: (1) Make the unistd.h include conditional on
1128        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1129    
1130    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1131        ncurses library to be included for pcretest when ReadLine support is
1132        requested, but also to allow for it to be overridden. This patch came from
1133        Daniel Bergström.
1134    
1135    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1136        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1137        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1138        spotting this.
1139    
1140    
1141    Version 7.6 28-Jan-08
1142    ---------------------
1143    
1144    1.  A character class containing a very large number of characters with
1145        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1146        overflow.
1147    
1148    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1149        HAVE_LONG_LONG is not defined.
1150    
1151    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1152        bring them up to date and include new features. This patch includes:
1153    
1154        - Fixed PH's badly added libz and libbz2 support.
1155        - Fixed a problem with static linking.
1156        - Added pcredemo. [But later removed - see 7 below.]
1157        - Fixed dftables problem and added an option.
1158        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1159            HAVE_LONG_LONG.
1160        - Added readline support for pcretest.
1161        - Added an listing of the option settings after cmake has run.
1162    
1163    4.  A user submitted a patch to Makefile that makes it easy to create
1164        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1165        Makefile.am that cause it to include this special target, without
1166        affecting anything else. Note that the same mingw target plus all
1167        the other distribution libraries and programs are now supported
1168        when configuring with CMake (see 6 below) instead of with
1169        Configure/Make.
1170    
1171    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1172        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1173        exported in the Windows port". It has not yet been confirmed that the patch
1174        solves the problem, but it does no harm.
1175    
1176    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1177        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1178        with CMake, and also correct the comment about stack recursion.
1179    
1180    7.  Remove the automatic building of pcredemo from the ./configure system and
1181        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1182        of a program that users should build themselves after PCRE is installed, so
1183        building it automatically is not really right. What is more, it gave
1184        trouble in some build environments.
1185    
1186    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1187    
1188    
1189    Version 7.5 10-Jan-08
1190    ---------------------
1191    
1192    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1193        values in parens when parsing an RE using the C++ wrapper."
1194    
1195    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1196        Characters greater than 255 were excluded from the class instead of being
1197        included.
1198    
1199    3.  The same bug as (2) above applied to negated POSIX classes such as
1200        [:^space:].
1201    
1202    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1203        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1204        I have changed it.
1205    
1206    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1207        first named subpattern) and a construct such as (?&a) would reference the
1208        first named subpattern whose name started with "a" (in other words, the
1209        length check was missing). Both these problems are fixed. "Subpattern name
1210        expected" is now given for (?&) (a zero-length name), and this patch also
1211        makes it give the same error for \k'' (previously it complained that that
1212        was a reference to a non-existent subpattern).
1213    
1214    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1215        this is right because (?- can be followed by option settings as well as by
1216        digits. I have, however, made the messages clearer.
1217    
1218    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1219        than the number used in the conditional) now cause a compile-time error.
1220        This is actually not compatible with Perl, which accepts such patterns, but
1221        treats the conditional as always being FALSE (as PCRE used to), but it
1222        seems to me that giving a diagnostic is better.
1223    
1224    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1225        and messages.
1226    
1227    9.  Fix two occurrences of "backslash" in comments that should have been
1228        "backspace".
1229    
1230    10. Remove two redundant lines of code that can never be obeyed (their function
1231        was moved elsewhere).
1232    
1233    11. The program that makes PCRE's Unicode character property table had a bug
1234        which caused it to generate incorrect table entries for sequences of
1235        characters that have the same character type, but are in different scripts.
1236        It amalgamated them into a single range, with the script of the first of
1237        them. In other words, some characters were in the wrong script. There were
1238        thirteen such cases, affecting characters in the following ranges:
1239    
1240          U+002b0 - U+002c1
1241          U+0060c - U+0060d
1242          U+0061e - U+00612
1243          U+0064b - U+0065e
1244          U+0074d - U+0076d
1245          U+01800 - U+01805
1246          U+01d00 - U+01d77
1247          U+01d9b - U+01dbf
1248          U+0200b - U+0200f
1249          U+030fc - U+030fe
1250          U+03260 - U+0327f
1251          U+0fb46 - U+0fbb1
1252          U+10450 - U+1049d
1253    
1254    12. The -o option (show only the matching part of a line) for pcregrep was not
1255        compatible with GNU grep in that, if there was more than one match in a
1256        line, it showed only the first of them. It now behaves in the same way as
1257        GNU grep.
1258    
1259    13. If the -o and -v options were combined for pcregrep, it printed a blank
1260        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1261        does the same. The return code can be used to tell if there were any
1262        non-matching lines.
1263    
1264    14. Added --file-offsets and --line-offsets to pcregrep.
1265    
1266    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1267        infinitely looping recursion. The bug was that positive lookaheads were not
1268        being skipped when checking for a possible empty match (negative lookaheads
1269        and both kinds of lookbehind were skipped).
1270    
1271    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1272        inclusion of <windows.h> to before rather than after the definition of
1273        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1274    
1275    17. Specifying a possessive quantifier with a specific limit for a Unicode
1276        character property caused pcre_compile() to compile bad code, which led at
1277        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1278        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1279        caused the error; without that there was no problem.
1280    
1281    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1282    
1283    19. Added --enable-pcretest-libreadline.
1284    
1285    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1286        RE::GlobalReplace(). As a result, the number of replacements returned was
1287        double what it should be. I removed one of the increments, but Craig sent a
1288        later patch that removed the other one (the right fix) and added unit tests
1289        that check the return values (which was not done before).
1290    
1291    21. Several CMake things:
1292    
1293        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1294            the names libpcre and libpcreposix, not just pcre and pcreposix.
1295    
1296        (2) The above change means that pcretest and pcregrep are now correctly
1297            linked with the newly-built libraries, not previously installed ones.
1298    
1299        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1300    
1301    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1302        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1303        UTF-8 newline character). The key issue is that the pattern starts .*;
1304        this means that the match must be either at the beginning, or after a
1305        newline. The bug was in the code for advancing after a failed match and
1306        checking that the new position followed a newline. It was not taking
1307        account of UTF-8 characters correctly.
1308    
1309    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1310        character classes. PCRE was not treating the sequence [:...:] as a
1311        character class unless the ... were all letters. Perl, however, seems to
1312        allow any characters between [: and :], though of course it rejects as
1313        unknown any "names" that contain non-letters, because all the known class
1314        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1315        for example, whereas PCRE did not - it did not recognize a POSIX character
1316        class. This seemed a bit dangerous, so the code has been changed to be
1317        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1318        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1319        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1320        Perl does, and where it didn't before.
1321    
1322    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1323        Windows environments %n is disabled by default.
1324    
1325    
1326    Version 7.4 21-Sep-07
1327  ---------------------  ---------------------
1328    
1329   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1330      that is more "standard", making use of automake and other autotools.      means that a class such as [\s] counted as "explicit reference to CR or
1331        LF". That isn't really right - the whole point of the change was to try to
1332        help when there was an actual mention of one of the two characters. So now
1333        the change happens only if \r or \n (or a literal CR or LF) character is
1334        encountered.
1335    
1336    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1337        of both had grown to the point where there were only 3 bits left.
1338        Fortunately, there was spare space in the data structure, and so I have
1339        moved the internal flags into a new 16-bit field to free up more option
1340        bits.
1341    
1342    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1343        but did not set the internal JCHANGED flag - either of these is enough to
1344        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1345        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1346        start sets both bits.
1347    
1348    4.  Added options (at build time, compile time, exec time) to change \R from
1349        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1350    
1351    5.  doc/pcresyntax.html was missing from the distribution.
1352    
1353    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1354        compatibility, even though it is no longer used.
1355    
1356    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1357        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1358        windows.h file is present (where different names are used). [This was
1359        reversed later after testing - see 16 below.]
1360    
1361    8.  Changed all #include <config.h> to #include "config.h". There were also
1362        some further <pcre.h> cases that I changed to "pcre.h".
1363    
1364    9.  When pcregrep was used with the --colour option, it missed the line ending
1365        sequence off the lines that it output.
1366    
1367    10. It was pointed out to me that arrays of string pointers cause lots of
1368        relocations when a shared library is dynamically loaded. A technique of
1369        using a single long string with a table of offsets can drastically reduce
1370        these. I have refactored PCRE in four places to do this. The result is
1371        dramatic:
1372    
1373          Originally:                          290
1374          After changing UCP table:            187
1375          After changing error message table:   43
1376          After changing table of "verbs"       36
1377          After changing table of Posix names   22
1378    
1379        Thanks to the folks working on Gregex for glib for this insight.
1380    
1381    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1382        unicode-properties was also set.
1383    
1384    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1385    
1386    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1387        checked only for CRLF.
1388    
1389    14. Added casts to pcretest.c to avoid compiler warnings.
1390    
1391    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1392    
1393    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1394        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1395        entirely. This removes changes made in 7 above.
1396    
1397    17. The CMake files have been updated, and there is now more information about
1398        building with CMake in the NON-UNIX-USE document.
1399    
1400    
1401    Version 7.3 28-Aug-07
1402    ---------------------
1403    
1404     1. In the rejigging of the build system that eventually resulted in 7.1, the
1405        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1406        brackets there is not right, since it causes compilers to look for an
1407        installed pcre.h, not the version that is in the source that is being
1408        compiled (which of course may be different). I have changed it back to:
1409    
1410          #include "pcre.h"
1411    
1412        I have a vague recollection that the change was concerned with compiling in
1413        different directories, but in the new build system, that is taken care of
1414        by the VPATH setting the Makefile.
1415    
1416     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1417        when the subject happened to end in the byte 0x85 (e.g. if the last
1418        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1419        characters but of course it shouldn't be taken as a newline when it is part
1420        of another character. The bug was that, for an unlimited repeat of . in
1421        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1422        characters when looking for a newline.
1423    
1424     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1425    
1426     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1427        in debug output.
1428    
1429     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1430        long printing in the pcrecpp unittest when running under MinGW.
1431    
1432     6. ESC_K was left out of the EBCDIC table.
1433    
1434     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1435        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1436        limit also applies to "virtual nesting" when a pattern is recursive, and in
1437        this case 1000 isn't so big. I have been able to remove this limit at the
1438        expense of backing off one optimization in certain circumstances. Normally,
1439        when pcre_exec() would call its internal match() function recursively and
1440        immediately return the result unconditionally, it uses a "tail recursion"
1441        feature to save stack. However, when a subpattern that can match an empty
1442        string has an unlimited repetition quantifier, it no longer makes this
1443        optimization. That gives it a stack frame in which to save the data for
1444        checking that an empty string has been matched. Previously this was taken
1445        from the 1000-entry workspace that had been reserved. So now there is no
1446        explicit limit, but more stack is used.
1447    
1448     8. Applied Daniel's patches to solve problems with the import/export magic
1449        syntax that is required for Windows, and which was going wrong for the
1450        pcreposix and pcrecpp parts of the library. These were overlooked when this
1451        problem was solved for the main library.
1452    
1453     9. There were some crude static tests to avoid integer overflow when computing
1454        the size of patterns that contain repeated groups with explicit upper
1455        limits. As the maximum quantifier is 65535, the maximum group length was
1456        set at 30,000 so that the product of these two numbers did not overflow a
1457        32-bit integer. However, it turns out that people want to use groups that
1458        are longer than 30,000 bytes (though not repeat them that many times).
1459        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1460        made it possible to implement the integer overflow checks in a much more
1461        dynamic way, which I have now done. The artificial limitation on group
1462        length has been removed - we now have only the limit on the total length of
1463        the compiled pattern, which depends on the LINK_SIZE setting.
1464    
1465    10. Fixed a bug in the documentation for get/copy named substring when
1466        duplicate names are permitted. If none of the named substrings are set, the
1467        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1468        empty string.
1469    
1470    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1471        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1472        because the ] is interpreted as the first data character and the
1473        terminating ] is not found. PCRE has been made compatible with Perl in this
1474        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1475        cause memory overwriting.
1476    
1477    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1478        string has been matched (to stop an infinite loop). It was not recognizing
1479        a conditional subpattern that could match an empty string if that
1480        subpattern was within another subpattern. For example, it looped when
1481        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1482        condition was not nested. This bug has been fixed.
1483    
1484    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1485        past the start of the subject in the presence of bytes with the top bit
1486        set, for example "\x8aBCD".
1487    
1488    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1489        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1490    
1491    14. Optimized (?!) to (*FAIL).
1492    
1493    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1494        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1495        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1496        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1497        does: it's just the validity check that is more restrictive.
1498    
1499    16. Inserted checks for integer overflows during escape sequence (backslash)
1500        processing, and also fixed erroneous offset values for syntax errors during
1501        backslash processing.
1502    
1503    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1504        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1505    
1506    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1507        caused an overrun.
1508    
1509    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1510        something other than just ASCII characters) inside a group that had an
1511        unlimited repeat caused a loop at compile time (while checking to see
1512        whether the group could match an empty string).
1513    
1514    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1515        [\P{Any}] did so. (Error in the code for printing property names.)
1516    
1517    21. An orphan \E inside a character class could cause a crash.
1518    
1519    22. A repeated capturing bracket such as (A)? could cause a wild memory
1520        reference during compilation.
1521    
1522    23. There are several functions in pcre_compile() that scan along a compiled
1523        expression for various reasons (e.g. to see if it's fixed length for look
1524        behind). There were bugs in these functions when a repeated \p or \P was
1525        present in the pattern. These operators have additional parameters compared
1526        with \d, etc, and these were not being taken into account when moving along
1527        the compiled data. Specifically:
1528    
1529        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1530            length.
1531    
1532        (b) An item such as \pL+ within a repeated group could cause crashes or
1533            loops.
1534    
1535        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1536            "reference to non-existent subpattern" error.
1537    
1538        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1539    
1540    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1541        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1542    
1543    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1544    
1545    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1546        character were causing crashes (broken optimization).
1547    
1548    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1549        \p or \P) caused a compile-time loop.
1550    
1551    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1552        break. For example, the unstudied pattern [\r\n]A does not match the string
1553        "\r\nA" because change 7.0/46 below moves the current point on by two
1554        characters after failing to match at the start. However, the pattern \nA
1555        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1556        the same is true. There doesn't seem any very clean way out of this, but
1557        what I have chosen to do makes the common cases work: PCRE now takes note
1558        of whether there can be an explicit match for \r or \n anywhere in the
1559        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1560        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1561        pattern has explicit CR or LF references.
1562    
1563    29. Added (*CR) etc for changing newline setting at start of pattern.
1564    
1565    
1566    Version 7.2 19-Jun-07
1567    ---------------------
1568    
1569     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1570        which is apparently normally available under Windows.
1571    
1572     2. Re-jig the pcregrep tests with different newline settings in an attempt
1573        to make them independent of the local environment's newline setting.
1574    
1575     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1576    
1577     4. Some of the "internals" tests were previously cut out when the link size
1578        was not 2, because the output contained actual offsets. The recent new
1579        "Z" feature of pcretest means that these can be cut out, making the tests
1580        usable with all link sizes.
1581    
1582     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1583        stack recursion. This gives a massive performance boost under BSD, but just
1584        a small improvement under Linux. However, it saves one field in the frame
1585        in all cases.
1586    
1587     6. Added more features from the forthcoming Perl 5.10:
1588    
1589        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1590            recursion call. It refers to the nth most recently opened parentheses.
1591    
1592        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1593            to be opened parentheses.
1594    
1595        (c) Conditions that refer to capturing parentheses can be specified
1596            relatively, for example, (?(-2)... or (?(+3)...
1597    
1598        (d) \K resets the start of the current match so that everything before
1599            is not part of it.
1600    
1601        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1602    
1603        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1604            reference syntax.
1605    
1606        (g) (?| introduces a group in which the numbering of parentheses in each
1607            alternative starts with the same number.
1608    
1609        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1610    
1611     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1612        PCRE_INFO_JCHANGED.
1613    
1614     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1615        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1616        for detecting groups that can match an empty string.
1617    
1618     9. A pattern with a very large number of alternatives (more than several
1619        hundred) was running out of internal workspace during the pre-compile
1620        phase, where pcre_compile() figures out how much memory will be needed. A
1621        bit of new cunning has reduced the workspace needed for groups with
1622        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1623        workspace instead of running out of the 4096 that are available.
1624    
1625    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1626    
1627    11. Applied patch from Google to remove an optimization that didn't quite work.
1628        The report of the bug said:
1629    
1630          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1631          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1632          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1633    
1634    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1635        it matched the wrong number of bytes.
1636    
1637    
1638    Version 7.1 24-Apr-07
1639    ---------------------
1640    
1641     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1642        that is more "standard", making use of automake and other Autotools. There
1643        is some re-arrangement of the files and adjustment of comments consequent
1644        on this.
1645    
1646     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1647        for recursive directory scanning broke on some systems because the files
1648        are not scanned in any specific order and on different systems the order
1649        was different. A call to "sort" has been inserted into RunGrepTest for the
1650        approprate test as a short-term fix. In the longer term there may be an
1651        alternative.
1652    
1653     3. I had an email from Eric Raymond about problems translating some of PCRE's
1654        man pages to HTML (despite the fact that I distribute HTML pages, some
1655        people do their own conversions for various reasons). The problems
1656        concerned the use of low-level troff macros .br and .in. I have therefore
1657        removed all such uses from the man pages (some were redundant, some could
1658        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1659        HTML has been updated to handle .nf/.fi and to complain if it encounters
1660        .br or .in.
1661    
1662     4. Updated comments in configure.ac that get placed in config.h.in and also
1663        arranged for config.h to be included in the distribution, with the name
1664        config.h.generic, for the benefit of those who have to compile without
1665        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1666    
1667     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1668        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1669        makevp.bat for the current PCRE, using the additional files
1670        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1671    
1672     6. A Windows user reported a minor discrepancy with test 2, which turned out
1673        to be caused by a trailing space on an input line that had got lost in his
1674        copy. The trailing space was an accident, so I've just removed it.
1675    
1676     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1677        that is needed.
1678    
1679     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1680        as "const" (a) because they are and (b) because it helps the PHP
1681        maintainers who have recently made a script to detect big data structures
1682        in the php code that should be moved to the .rodata section. I remembered
1683        to update Builducptable as well, so it won't revert if ucptable.h is ever
1684        re-created.
1685    
1686     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1687        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1688        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1689        support is not required. This saves 1.5-2K of code, which is important in
1690        some applications.
1691    
1692        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1693        so as not to refer to the tables, even though these functions will never be
1694        called when UTF-8 support is disabled. Otherwise there are problems with a
1695        shared library.
1696    
1697    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1698    
1699        (a) It was defining its arguments as char * instead of void *.
1700    
1701        (b) It was assuming that all moves were upwards in memory; this was true
1702            a long time ago when I wrote it, but is no longer the case.
1703    
1704        The emulated memove() is provided for those environments that have neither
1705        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1706        is clearly not the case, as these two bugs were recently reported.
1707    
1708    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1709        and Detrail to create the HTML documentation, the .txt form of the man
1710        pages, and it removes trailing spaces from listed files. It also creates
1711        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1712        case, it wraps all the #defines with #ifndefs. This script should be run
1713        before "make dist".
1714    
1715    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1716        with Unicode property support.
1717    
1718        (a) For a maximizing quantifier, if the two different cases of the
1719            character were of different lengths in their UTF-8 codings (there are
1720            some cases like this - I found 11), and the matching function had to
1721            back up over a mixture of the two cases, it incorrectly assumed they
1722            were both the same length.
1723    
1724        (b) When PCRE was configured to use the heap rather than the stack for
1725            recursion during matching, it was not correctly preserving the data for
1726            the other case of a UTF-8 character when checking ahead for a match
1727            while processing a minimizing repeat. If the check also involved
1728            matching a wide character, but failed, corruption could cause an
1729            erroneous result when trying to check for a repeat of the original
1730            character.
1731    
1732    13. Some tidying changes to the testing mechanism:
1733    
1734        (a) The RunTest script now detects the internal link size and whether there
1735            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1736            values substituted by "configure". (The RunGrepTest script already did
1737            this for UTF-8.) The configure.ac script no longer substitutes the
1738            relevant variables.
1739    
1740        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1741            with length and offset values. This means that the output is different
1742            for different internal link sizes. Test 2 is skipped for link sizes
1743            other than 2 because of this, bypassing the problem. Unfortunately,
1744            there was also a test in test 3 (the locale tests) that used /B and
1745            failed for link sizes other than 2. Rather than cut the whole test out,
1746            I have added a new /Z option to pcretest that replaces the length and
1747            offset values with spaces. This is now used to make test 3 independent
1748            of link size. (Test 2 will be tidied up later.)
1749    
1750    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1751        segmentation fault instead of returning the appropriate error message.
1752    
1753    15. In multiline mode when the newline sequence was set to "any", the pattern
1754        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1755        This doesn't seem right; it now treats the CRLF combination as the line
1756        ending, and so does not match in that case. It's only a pattern such as ^$
1757        that would hit this one: something like ^ABC$ would have failed after \r
1758        and then tried again after \r\n.
1759    
1760    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1761        in an attempt to make files that differ only in their line terminators
1762        compare equal. This works on Linux.
1763    
1764    17. Under certain error circumstances pcregrep might try to free random memory
1765        as it exited. This is now fixed, thanks to valgrind.
1766    
1767    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1768        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1769        was because its rules for how to advance for /g after matching an empty
1770        string at the end of a line did not allow for this case. They now check for
1771        it specially.
1772    
1773    20. pcretest is supposed to handle patterns and data of any length, by
1774        extending its buffers when necessary. It was getting this wrong when the
1775        buffer for a data line had to be extended.
1776    
1777    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1778        CRLF as a newline sequence.
1779    
1780    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1781        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1782        I have nevertheless tidied it up.
1783    
1784    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1785    
1786    24. Added a man page for pcre-config.
1787    
1788    
1789  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06

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