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revision 105 by ph10, Tue Mar 6 16:32:53 2007 UTC revision 556 by ph10, Tue Oct 26 11:06:44 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 8.11 10-Oct-2010
5    ------------------------
6    
7    1.  (*THEN) was not working properly if there were untried alternatives prior
8        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9        backtracked to try for "b" instead of moving to the next alternative branch
10        at the same level (in this case, to look for "c"). The Perl documentation
11        is clear that when (*THEN) is backtracked onto, it goes to the "next
12        alternative in the innermost enclosing group".
13    
14    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
16        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18        (*THEN).
19    
20    3.  If \s appeared in a character class, it removed the VT character from
21        the class, even if it had been included by some previous item, for example
22        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23        of \s, but is part of the POSIX "space" class.)
24    
25    4.  A partial match never returns an empty string (because you can always
26        match an empty string at the end of the subject); however the checking for
27        an empty string was starting at the "start of match" point. This has been
28        changed to the "earliest inspected character" point, because the returned
29        data for a partial match starts at this character. This means that, for
30        example, /(?<=abc)def/ gives a partial match for the subject "abc"
31        (previously it gave "no match").
32    
33    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36        has an implication that the given string is incomplete (because a partial
37        match is preferred over a full match). For this reason, these items now
38        give a partial match in this situation. [Aside: previously, the one case
39        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40        match rather than a full match, which was wrong by the old rules, but is
41        now correct.]
42    
43    6.  There was a bug in the handling of #-introduced comments, recognized when
44        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49        places in pcre_compile().
50    
51    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
52        comments when looking ahead for named forward references to subpatterns,
53        the only newline sequence it recognized was NL. It now handles newlines
54        according to the set newline convention.
55    
56    
57    Version 8.10 25-Jun-2010
58    ------------------------
59    
60    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
61        THEN.
62    
63    2.  (*ACCEPT) was not working when inside an atomic group.
64    
65    3.  Inside a character class, \B is treated as a literal by default, but
66        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
67        causes the error). The code is unchanged, but I tidied the documentation.
68    
69    4.  Inside a character class, PCRE always treated \R and \X as literals,
70        whereas Perl faults them if its -w option is set. I have changed PCRE so
71        that it faults them when PCRE_EXTRA is set.
72    
73    5.  Added support for \N, which always matches any character other than
74        newline. (It is the same as "." when PCRE_DOTALL is not set.)
75    
76    6.  When compiling pcregrep with newer versions of gcc which may have
77        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
78        declared with attribute warn_unused_result" were given. Just casting the
79        result to (void) does not stop the warnings; a more elaborate fudge is
80        needed. I've used a macro to implement this.
81    
82    7.  Minor change to pcretest.c to avoid a compiler warning.
83    
84    8.  Added four artifical Unicode properties to help with an option to make
85        \s etc use properties (see next item). The new properties are: Xan
86        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
87    
88    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
89        use Unicode properties. (*UCP) at the start of a pattern can be used to set
90        this option. Modified pcretest to add /W to test this facility. Added
91        REG_UCP to make it available via the POSIX interface.
92    
93    10. Added --line-buffered to pcregrep.
94    
95    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
96        studied, and the match started with a letter with a code point greater than
97        127 whose first byte was different to the first byte of the other case of
98        the letter, the other case of this starting letter was not recognized
99        (#976).
100    
101    12. If a pattern that was studied started with a repeated Unicode property
102        test, for example, \p{Nd}+, there was the theoretical possibility of
103        setting up an incorrect bitmap of starting bytes, but fortunately it could
104        not have actually happened in practice until change 8 above was made (it
105        added property types that matched character-matching opcodes).
106    
107    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
108        possible starting bytes for non-anchored patterns.
109    
110    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
111        \R, and also a number of cases that involve Unicode properties, both
112        explicit and implicit when PCRE_UCP is set.
113    
114    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
115        input, it could crash or give wrong results if characters with values
116        greater than 0xc0 were present in the subject string. (Detail: it assumed
117        UTF-8 input when processing these items.)
118    
119    16. Added a lot of (int) casts to avoid compiler warnings in systems where
120        size_t is 64-bit (#991).
121    
122    17. Added a check for running out of memory when PCRE is compiled with
123        --disable-stack-for-recursion (#990).
124    
125    18. If the last data line in a file for pcretest does not have a newline on
126        the end, a newline was missing in the output.
127    
128    19. The default pcre_chartables.c file recognizes only ASCII characters (values
129        less than 128) in its various bitmaps. However, there is a facility for
130        generating tables according to the current locale when PCRE is compiled. It
131        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
132        characters, are recognized by isspace() and therefore were getting set in
133        these tables, and indeed these tables seem to approximate to ISO 8859. This
134        caused a problem in UTF-8 mode when pcre_study() was used to create a list
135        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
136        which of course cannot start UTF-8 characters. I have changed the code so
137        that only real ASCII characters (less than 128) and the correct starting
138        bytes for UTF-8 encodings are set for characters greater than 127 when in
139        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
140        altogether.)
141    
142    20. Added the /T option to pcretest so as to be able to run tests with non-
143        standard character tables, thus making it possible to include the tests
144        used for 19 above in the standard set of tests.
145    
146    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
147        reference to a subpattern the other side of a comment that contains an
148        opening parenthesis caused either an internal compiling error, or a
149        reference to the wrong subpattern.
150    
151    
152    Version 8.02 19-Mar-2010
153    ------------------------
154    
155    1.  The Unicode data tables have been updated to Unicode 5.2.0.
156    
157    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
158        configured.
159    
160    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
161        original author of that file, following a query about its status.
162    
163    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
164        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
165    
166    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
167        quantifier applied to a forward-referencing subroutine call, could compile
168        incorrect code or give the error "internal error: previously-checked
169        referenced subpattern not found".
170    
171    6.  Both MS Visual Studio and Symbian OS have problems with initializing
172        variables to point to external functions. For these systems, therefore,
173        pcre_malloc etc. are now initialized to local functions that call the
174        relevant global functions.
175    
176    7.  There were two entries missing in the vectors called coptable and poptable
177        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
178        I've fixed the data, and added a kludgy way of testing at compile time that
179        the lengths are correct (equal to the number of opcodes).
180    
181    8.  Following on from 7, I added a similar kludge to check the length of the
182        eint vector in pcreposix.c.
183    
184    9.  Error texts for pcre_compile() are held as one long string to avoid too
185        much relocation at load time. To find a text, the string is searched,
186        counting zeros. There was no check for running off the end of the string,
187        which could happen if a new error number was added without updating the
188        string.
189    
190    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
191    
192    11. \K was not working if it appeared in an atomic group or in a group that
193        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
194        \K is "not well defined" if used in an assertion. PCRE now accepts it if
195        the assertion is positive, but not if it is negative.
196    
197    12. Change 11 fortuitously reduced the size of the stack frame used in the
198        "match()" function of pcre_exec.c by one pointer. Forthcoming
199        implementation of support for (*MARK) will need an extra pointer on the
200        stack; I have reserved it now, so that the stack frame size does not
201        decrease.
202    
203    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
204        item in branch that calls a recursion is a subroutine call - as in the
205        second branch in the above example - was incorrectly given the compile-
206        time error "recursive call could loop indefinitely" because pcre_compile()
207        was not correctly checking the subroutine for matching a non-empty string.
208    
209    14. The checks for overrunning compiling workspace could trigger after an
210        overrun had occurred. This is a "should never occur" error, but it can be
211        triggered by pathological patterns such as hundreds of nested parentheses.
212        The checks now trigger 100 bytes before the end of the workspace.
213    
214    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
215    
216    
217    Version 8.01 19-Jan-2010
218    ------------------------
219    
220    1.  If a pattern contained a conditional subpattern with only one branch (in
221        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
222        computed the wrong minimum data length (which is of course zero for such
223        subpatterns). This could cause incorrect "no match" results.
224    
225    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
226        the pattern is reset in the first branch, pcre_compile() failed with
227        "internal error: code overflow at offset...". This happened only when
228        the reset was to the original external option setting. (An optimization
229        abstracts leading options settings into an external setting, which was the
230        cause of this.)
231    
232    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
233        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
234        assertion pattern did not match (meaning that the assertion was true), it
235        was incorrectly treated as false if the SKIP had been reached during the
236        matching. This also applied to assertions used as conditions.
237    
238    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
239        assertion subpattern, including such a pattern used as a condition,
240        unpredictable results occurred, instead of the error return
241        PCRE_ERROR_DFA_UITEM.
242    
243    5.  The C++ GlobalReplace function was not working like Perl for the special
244        situation when an empty string is matched. It now does the fancy magic
245        stuff that is necessary.
246    
247    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
248        removed. (These were left over from very, very early versions of PCRE.)
249    
250    7.  Some cosmetic changes to the code to make life easier when compiling it
251        as part of something else:
252    
253        (a) Change DEBUG to PCRE_DEBUG.
254    
255        (b) In pcre_compile(), rename the member of the "branch_chain" structure
256            called "current" as "current_branch", to prevent a collision with the
257            Linux macro when compiled as a kernel module.
258    
259        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
260            prevent a collision with the Linux macro when compiled as a kernel
261            module.
262    
263    8.  In pcre_compile() there are some checks for integer overflows that used to
264        cast potentially large values to (double). This has been changed to that
265        when building, a check for int64_t is made, and if it is found, it is used
266        instead, thus avoiding the use of floating point arithmetic. (There is no
267        other use of FP in PCRE.) If int64_t is not found, the fallback is to
268        double.
269    
270    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
271        2005 (difference between two addresses compared to an unsigned value).
272    
273    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
274        custom one, because of the following reported problem in Windows:
275    
276          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
277              under Win32.
278          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
279              therefore missing the function definition.
280          - The compiler thus generates a "C" signature for the test function.
281          - The linker fails to find the "C" function.
282          - PCRE fails to configure if asked to do so against libbz2.
283    
284    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
285        messages were output:
286    
287          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
288          rerunning libtoolize, to keep the correct libtool macros in-tree.
289          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
290    
291        I have done both of these things.
292    
293    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
294        most of the time, it *can* run out if it is given a pattern that contains a
295        runaway infinite recursion. I updated the discussion in the pcrestack man
296        page.
297    
298    13. Now that we have gone to the x.xx style of version numbers, the minor
299        version may start with zero. Using 08 or 09 is a bad idea because users
300        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
301        interpreted as invalid octal numbers. I've updated the previous comment in
302        configure.ac, and also added a check that gives an error if 08 or 09 are
303        used.
304    
305    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
306        causing partial matching to fail when the end of the subject matched \W
307        in a UTF-8 pattern where \W was quantified with a minimum of 3.
308    
309    15. There were some discrepancies between the declarations in pcre_internal.h
310        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
311        their definitions. The declarations used "const uschar *" and the
312        definitions used USPTR. Even though USPTR is normally defined as "const
313        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
314        reported that: "This difference in casting confuses some C++ compilers, for
315        example, SunCC recognizes above declarations as different functions and
316        generates broken code for hbpcre." I have changed the declarations to use
317        USPTR.
318    
319    16. GNU libtool is named differently on some systems. The autogen.sh script now
320        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
321        (FreeBSD).
322    
323    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
324        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
325        comment: "Figure out how to create a longlong from a string: strtoll and
326        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
327        instance, but it only takes 2 args instead of 3!"
328    
329    18. A subtle bug concerned with back references has been fixed by a change of
330        specification, with a corresponding code fix. A pattern such as
331        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
332        refers, was giving matches when it shouldn't. For example, xa=xaaa would
333        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
334        same bug. Such groups have to be quantified to be useful, or contained
335        inside another quantified group. (If there's no repetition, the reference
336        can never match.) The problem arises because, having left the group and
337        moved on to the rest of the pattern, a later failure that backtracks into
338        the group uses the captured value from the final iteration of the group
339        rather than the correct earlier one. I have fixed this in PCRE by forcing
340        any group that contains a reference to itself to be an atomic group; that
341        is, there cannot be any backtracking into it once it has completed. This is
342        similar to recursive and subroutine calls.
343    
344    
345    Version 8.00 19-Oct-09
346    ----------------------
347    
348    1.  The table for translating pcre_compile() error codes into POSIX error codes
349        was out-of-date, and there was no check on the pcre_compile() error code
350        being within the table. This could lead to an OK return being given in
351        error.
352    
353    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
354        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
355        in a Windows environment.
356    
357    3.  The pcregrep --count option prints the count for each file even when it is
358        zero, as does GNU grep. However, pcregrep was also printing all files when
359        --files-with-matches was added. Now, when both options are given, it prints
360        counts only for those files that have at least one match. (GNU grep just
361        prints the file name in this circumstance, but including the count seems
362        more useful - otherwise, why use --count?) Also ensured that the
363        combination -clh just lists non-zero counts, with no names.
364    
365    4.  The long form of the pcregrep -F option was incorrectly implemented as
366        --fixed_strings instead of --fixed-strings. This is an incompatible change,
367        but it seems right to fix it, and I didn't think it was worth preserving
368        the old behaviour.
369    
370    5.  The command line items --regex=pattern and --regexp=pattern were not
371        recognized by pcregrep, which required --regex pattern or --regexp pattern
372        (with a space rather than an '='). The man page documented the '=' forms,
373        which are compatible with GNU grep; these now work.
374    
375    6.  No libpcreposix.pc file was created for pkg-config; there was just
376        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
377    
378    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
379        when UCP support is not needed, by modifying the Python script that
380        generates it from Unicode data files. This should not matter if the module
381        is correctly used as a library, but I received one complaint about 50K of
382        unwanted data. My guess is that the person linked everything into his
383        program rather than using a library. Anyway, it does no harm.
384    
385    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
386        was a minimum greater than 1 for a wide character in a possessive
387        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
388        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
389        character. Chaos in the form of incorrect output or a compiling loop could
390        result.
391    
392    9.  The restrictions on what a pattern can contain when partial matching is
393        requested for pcre_exec() have been removed. All patterns can now be
394        partially matched by this function. In addition, if there are at least two
395        slots in the offset vector, the offset of the earliest inspected character
396        for the match and the offset of the end of the subject are set in them when
397        PCRE_ERROR_PARTIAL is returned.
398    
399    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
400        synonymous with PCRE_PARTIAL, for backwards compatibility, and
401        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
402        and may be more useful for multi-segment matching.
403    
404    11. Partial matching with pcre_exec() is now more intuitive. A partial match
405        used to be given if ever the end of the subject was reached; now it is
406        given only if matching could not proceed because another character was
407        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
408        string "Z", which now yields "no match" instead of "partial match". In the
409        case of pcre_dfa_exec(), "no match" is given if every matching path for the
410        final character ended with (*FAIL).
411    
412    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
413        if the pattern had a "must contain" character that was already found in the
414        earlier partial match, unless partial matching was again requested. For
415        example, with the pattern /dog.(body)?/, the "must contain" character is
416        "g". If the first part-match was for the string "dog", restarting with
417        "sbody" failed. This bug has been fixed.
418    
419    13. The string returned by pcre_dfa_exec() after a partial match has been
420        changed so that it starts at the first inspected character rather than the
421        first character of the match. This makes a difference only if the pattern
422        starts with a lookbehind assertion or \b or \B (\K is not supported by
423        pcre_dfa_exec()). It's an incompatible change, but it makes the two
424        matching functions compatible, and I think it's the right thing to do.
425    
426    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
427        so that the demonstration program is easily available in environments where
428        PCRE has not been installed from source.
429    
430    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
431        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
432        library.
433    
434    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
435        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
436        is not the first non-POSIX option to be added. Clearly some people find
437        these options useful.
438    
439    17. If a caller to the POSIX matching function regexec() passes a non-zero
440        value for nmatch with a NULL value for pmatch, the value of
441        nmatch is forced to zero.
442    
443    18. RunGrepTest did not have a test for the availability of the -u option of
444        the diff command, as RunTest does. It now checks in the same way as
445        RunTest, and also checks for the -b option.
446    
447    19. If an odd number of negated classes containing just a single character
448        interposed, within parentheses, between a forward reference to a named
449        subpattern and the definition of the subpattern, compilation crashed with
450        an internal error, complaining that it could not find the referenced
451        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
452        [The bug was that it was starting one character too far in when skipping
453        over the character class, thus treating the ] as data rather than
454        terminating the class. This meant it could skip too much.]
455    
456    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
457        /g option in pcretest when the pattern contains \K, which makes it possible
458        to have an empty string match not at the start, even when the pattern is
459        anchored. Updated pcretest and pcredemo to use this option.
460    
461    21. If the maximum number of capturing subpatterns in a recursion was greater
462        than the maximum at the outer level, the higher number was returned, but
463        with unset values at the outer level. The correct (outer level) value is
464        now given.
465    
466    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
467        PCRE did not set those parentheses (unlike Perl). I have now found a way to
468        make it do so. The string so far is captured, making this feature
469        compatible with Perl.
470    
471    23. The tests have been re-organized, adding tests 11 and 12, to make it
472        possible to check the Perl 5.10 features against Perl 5.10.
473    
474    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
475        pattern matches a fixed length string. PCRE did not allow this; now it
476        does. Neither allows recursion.
477    
478    25. I finally figured out how to implement a request to provide the minimum
479        length of subject string that was needed in order to match a given pattern.
480        (It was back references and recursion that I had previously got hung up
481        on.) This code has now been added to pcre_study(); it finds a lower bound
482        to the length of subject needed. It is not necessarily the greatest lower
483        bound, but using it to avoid searching strings that are too short does give
484        some useful speed-ups. The value is available to calling programs via
485        pcre_fullinfo().
486    
487    26. While implementing 25, I discovered to my embarrassment that pcretest had
488        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
489        study optimizations had never been tested with that matching function.
490        Oops. What is worse, even when it was passed study data, there was a bug in
491        pcre_dfa_exec() that meant it never actually used it. Double oops. There
492        were also very few tests of studied patterns with pcre_dfa_exec().
493    
494    27. If (?| is used to create subpatterns with duplicate numbers, they are now
495        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
496        on the other side of the coin, they are no longer allowed to have different
497        names, because these cannot be distinguished in PCRE, and this has caused
498        confusion. (This is a difference from Perl.)
499    
500    28. When duplicate subpattern names are present (necessarily with different
501        numbers, as required by 27 above), and a test is made by name in a
502        conditional pattern, either for a subpattern having been matched, or for
503        recursion in such a pattern, all the associated numbered subpatterns are
504        tested, and the overall condition is true if the condition is true for any
505        one of them. This is the way Perl works, and is also more like the way
506        testing by number works.
507    
508    
509    Version 7.9 11-Apr-09
510    ---------------------
511    
512    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
513        (pcretest), all targets were linked against these libraries. This included
514        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
515        libraries. This caused unwanted dependencies to be created. This problem
516        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
517        pcretest is linked with readline.
518    
519    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
520        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
521        moved outside it again, because FALSE and TRUE are already defined in AIX,
522        but BOOL is not.
523    
524    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
525        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
526    
527    4.  The pcregrep documentation said spaces were inserted as well as colons (or
528        hyphens) following file names and line numbers when outputting matching
529        lines. This is not true; no spaces are inserted. I have also clarified the
530        wording for the --colour (or --color) option.
531    
532    5.  In pcregrep, when --colour was used with -o, the list of matching strings
533        was not coloured; this is different to GNU grep, so I have changed it to be
534        the same.
535    
536    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
537        each matching line was coloured. Now it goes on to look for further matches
538        of any of the test patterns, which is the same behaviour as GNU grep.
539    
540    7.  A pattern that could match an empty string could cause pcregrep to loop; it
541        doesn't make sense to accept an empty string match in pcregrep, so I have
542        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
543        seems to be how GNU grep behaves.
544    
545    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
546        start or after a newline", because the conditional assertion was not being
547        correctly handled. The rule now is that both the assertion and what follows
548        in the first alternative must satisfy the test.
549    
550    9.  If auto-callout was enabled in a pattern with a conditional group whose
551        condition was an assertion, PCRE could crash during matching, both with
552        pcre_exec() and pcre_dfa_exec().
553    
554    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
555        used for matching.
556    
557    11. Unicode property support in character classes was not working for
558        characters (bytes) greater than 127 when not in UTF-8 mode.
559    
560    12. Added the -M command line option to pcretest.
561    
562    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
563    
564    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
565    
566    16. Added comments and documentation about mis-use of no_arg in the C++
567        wrapper.
568    
569    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
570        from Martin Jerabek that uses macro names for all relevant character and
571        string constants.
572    
573    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
574        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
575        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
576        these, but not everybody uses configure.
577    
578    19. A conditional group that had only one branch was not being correctly
579        recognized as an item that could match an empty string. This meant that an
580        enclosing group might also not be so recognized, causing infinite looping
581        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
582        with the subject "ab", where knowledge that the repeated group can match
583        nothing is needed in order to break the loop.
584    
585    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
586        exec(), but without supplying a callout function, matching went wrong.
587    
588    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
589        leak if the size of the offset vector was greater than 30. When the vector
590        is smaller, the saved offsets during recursion go onto a local stack
591        vector, but for larger vectors malloc() is used. It was failing to free
592        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
593        error, in fact).
594    
595    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
596        heapframe that is used only when UTF-8 support is enabled. This caused no
597        problem, but was untidy.
598    
599    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
600        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
601        included within another project.
602    
603    24. Steven Van Ingelgem's patches to add more options to the CMake support,
604        slightly modified by me:
605    
606          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
607              not building pcregrep.
608    
609          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
610              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
611    
612    25. Forward references, both numeric and by name, in patterns that made use of
613        duplicate group numbers, could behave incorrectly or give incorrect errors,
614        because when scanning forward to find the reference group, PCRE was not
615        taking into account the duplicate group numbers. A pattern such as
616        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
617    
618    26. Changed a few more instances of "const unsigned char *" to USPTR, making
619        the feature of a custom pointer more persuasive (as requested by a user).
620    
621    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
622        pcretest.c, inside #ifndefs, because it seems they are sometimes already
623        pre-defined.
624    
625    28. Added support for (*UTF8) at the start of a pattern.
626    
627    29. Arrange for flags added by the "release type" setting in CMake to be shown
628        in the configuration summary.
629    
630    
631    Version 7.8 05-Sep-08
632  ---------------------  ---------------------
633    
634   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  Replaced UCP searching code with optimized version as implemented for Ad
635      that is more "standard", making use of automake and other autotools. There      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
636        stage table and inline lookup instead of a function, giving speed ups of 2
637        to 5 times on some simple patterns that I tested. Permission was given to
638        distribute the MultiStage2.py script that generates the tables (it's not in
639        the tarball, but is in the Subversion repository).
640    
641    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
642        scripts.
643    
644    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
645        a group with a zero qualifier. The result of the study could be incorrect,
646        or the function might crash, depending on the pattern.
647    
648    4.  Caseless matching was not working for non-ASCII characters in back
649        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
650        It now works when Unicode Property Support is available.
651    
652    5.  In pcretest, an escape such as \x{de} in the data was always generating
653        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
654        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
655        truncation.
656    
657    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
658    
659    7.  Added two (int) casts to pcregrep when printing the difference of two
660        pointers, in case they are 64-bit values.
661    
662    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
663        test 2 if it fails.
664    
665    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
666        and a #define of that name to empty if it is not externally set. This is to
667        allow users of MSVC to set it if necessary.
668    
669    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
670        the convenience functions in the pcre_get.c source file.
671    
672    11. An option change at the start of a pattern that had top-level alternatives
673        could cause overwriting and/or a crash. This command provoked a crash in
674        some environments:
675    
676          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
677    
678        This potential security problem was recorded as CVE-2008-2371.
679    
680    12. For a pattern where the match had to start at the beginning or immediately
681        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
682        pcre_dfa_exec() could read past the end of the passed subject if there was
683        no match. To help with detecting such bugs (e.g. with valgrind), I modified
684        pcretest so that it places the subject at the end of its malloc-ed buffer.
685    
686    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
687        exec() might read past the end of the data buffer in UTF-8 mode.
688    
689    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
690        the data contained the byte 0x85 as part of a UTF-8 character within its
691        first line. This applied both to normal and DFA matching.
692    
693    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
694        /^[^d]*?$/8 failed to match "abc".
695    
696    16. Added a missing copyright notice to pcrecpp_internal.h.
697    
698    17. Make it more clear in the documentation that values returned from
699        pcre_exec() in ovector are byte offsets, not character counts.
700    
701    18. Tidied a few places to stop certain compilers from issuing warnings.
702    
703    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
704        supplied by Stefan Weber. I made a further small update for 7.8 because
705        there is a change of source arrangements: the pcre_searchfuncs.c module is
706        replaced by pcre_ucd.c.
707    
708    
709    Version 7.7 07-May-08
710    ---------------------
711    
712    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
713        a string to a long long, pretend we don't even have a long long." This is
714        done by checking for the strtoq, strtoll, and _strtoi64 functions.
715    
716    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
717        pre-7.6 versions, which defined a global no_arg variable instead of putting
718        it in the RE class. (See also #8 below.)
719    
720    3.  Remove a line of dead code, identified by coverity and reported by Nuno
721        Lopes.
722    
723    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
724    
725        (1) The include/exclude patterns were being applied to the whole pathnames
726            of files, instead of just to the final components.
727    
728        (2) If there was more than one level of directory, the subdirectories were
729            skipped unless they satisfied the include/exclude conditions. This is
730            inconsistent with GNU grep (and could even be seen as contrary to the
731            pcregrep specification - which I improved to make it absolutely clear).
732            The action now is always to scan all levels of directory, and just
733            apply the include/exclude patterns to regular files.
734    
735    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
736        --exclude_dir in the tests to avoid scanning .svn directories.
737    
738    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
739        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
740        doesn't support NULs in patterns.
741    
742    7.  Added some missing "const"s to declarations of static tables in
743        pcre_compile.c and pcre_dfa_exec.c.
744    
745    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
746        caused by fix #2  above. (Subsequently also a second patch to fix the
747        first patch. And a third patch - this was a messy problem.)
748    
749    9.  Applied Craig's patch to remove the use of push_back().
750    
751    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
752        matching function regexec().
753    
754    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
755        which, however, unlike Perl's \g{...}, are subroutine calls, not back
756        references. PCRE supports relative numbers with this syntax (I don't think
757        Oniguruma does).
758    
759    12. Previously, a group with a zero repeat such as (...){0} was completely
760        omitted from the compiled regex. However, this means that if the group
761        was called as a subroutine from elsewhere in the pattern, things went wrong
762        (an internal error was given). Such groups are now left in the compiled
763        pattern, with a new opcode that causes them to be skipped at execution
764        time.
765    
766    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
767        to the way PCRE behaves:
768    
769        (a) A lone ] character is dis-allowed (Perl treats it as data).
770    
771        (b) A back reference to an unmatched subpattern matches an empty string
772            (Perl fails the current match path).
773    
774        (c) A data ] in a character class must be notated as \] because if the
775            first data character in a class is ], it defines an empty class. (In
776            Perl it is not possible to have an empty class.) The empty class []
777            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
778            The negative empty class [^] matches any one character, independently
779            of the DOTALL setting.
780    
781    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
782        non-existent subpattern following a character class starting with ']' and
783        containing () gave an internal compiling error instead of "reference to
784        non-existent subpattern". Fortunately, when the pattern did exist, the
785        compiled code was correct. (When scanning forwards to check for the
786        existencd of the subpattern, it was treating the data ']' as terminating
787        the class, so got the count wrong. When actually compiling, the reference
788        was subsequently set up correctly.)
789    
790    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
791        it was being rejected as not supported by pcre_dfa_exec(), even though
792        other assertions are supported. I have made pcre_dfa_exec() support
793        (*FAIL).
794    
795    16. The implementation of 13c above involved the invention of a new opcode,
796        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
797        cannot be changed at match time, I realized I could make a small
798        improvement to matching performance by compiling OP_ALLANY instead of
799        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
800        on the OP_ANY path.
801    
802    17. Compiling pcretest on Windows with readline support failed without the
803        following two fixes: (1) Make the unistd.h include conditional on
804        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
805    
806    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
807        ncurses library to be included for pcretest when ReadLine support is
808        requested, but also to allow for it to be overridden. This patch came from
809        Daniel Bergström.
810    
811    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
812        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
813        any errors with the current Unicode tables. Thanks to Peter Kankowski for
814        spotting this.
815    
816    
817    Version 7.6 28-Jan-08
818    ---------------------
819    
820    1.  A character class containing a very large number of characters with
821        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
822        overflow.
823    
824    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
825        HAVE_LONG_LONG is not defined.
826    
827    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
828        bring them up to date and include new features. This patch includes:
829    
830        - Fixed PH's badly added libz and libbz2 support.
831        - Fixed a problem with static linking.
832        - Added pcredemo. [But later removed - see 7 below.]
833        - Fixed dftables problem and added an option.
834        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
835            HAVE_LONG_LONG.
836        - Added readline support for pcretest.
837        - Added an listing of the option settings after cmake has run.
838    
839    4.  A user submitted a patch to Makefile that makes it easy to create
840        "pcre.dll" under mingw when using Configure/Make. I added stuff to
841        Makefile.am that cause it to include this special target, without
842        affecting anything else. Note that the same mingw target plus all
843        the other distribution libraries and programs are now supported
844        when configuring with CMake (see 6 below) instead of with
845        Configure/Make.
846    
847    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
848        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
849        exported in the Windows port". It has not yet been confirmed that the patch
850        solves the problem, but it does no harm.
851    
852    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
853        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
854        with CMake, and also correct the comment about stack recursion.
855    
856    7.  Remove the automatic building of pcredemo from the ./configure system and
857        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
858        of a program that users should build themselves after PCRE is installed, so
859        building it automatically is not really right. What is more, it gave
860        trouble in some build environments.
861    
862    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
863    
864    
865    Version 7.5 10-Jan-08
866    ---------------------
867    
868    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
869        values in parens when parsing an RE using the C++ wrapper."
870    
871    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
872        Characters greater than 255 were excluded from the class instead of being
873        included.
874    
875    3.  The same bug as (2) above applied to negated POSIX classes such as
876        [:^space:].
877    
878    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
879        defined or documented. It seems to have been a typo for PCRE_STATIC, so
880        I have changed it.
881    
882    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
883        first named subpattern) and a construct such as (?&a) would reference the
884        first named subpattern whose name started with "a" (in other words, the
885        length check was missing). Both these problems are fixed. "Subpattern name
886        expected" is now given for (?&) (a zero-length name), and this patch also
887        makes it give the same error for \k'' (previously it complained that that
888        was a reference to a non-existent subpattern).
889    
890    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
891        this is right because (?- can be followed by option settings as well as by
892        digits. I have, however, made the messages clearer.
893    
894    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
895        than the number used in the conditional) now cause a compile-time error.
896        This is actually not compatible with Perl, which accepts such patterns, but
897        treats the conditional as always being FALSE (as PCRE used to), but it
898        seems to me that giving a diagnostic is better.
899    
900    8.  Change "alphameric" to the more common word "alphanumeric" in comments
901        and messages.
902    
903    9.  Fix two occurrences of "backslash" in comments that should have been
904        "backspace".
905    
906    10. Remove two redundant lines of code that can never be obeyed (their function
907        was moved elsewhere).
908    
909    11. The program that makes PCRE's Unicode character property table had a bug
910        which caused it to generate incorrect table entries for sequences of
911        characters that have the same character type, but are in different scripts.
912        It amalgamated them into a single range, with the script of the first of
913        them. In other words, some characters were in the wrong script. There were
914        thirteen such cases, affecting characters in the following ranges:
915    
916          U+002b0 - U+002c1
917          U+0060c - U+0060d
918          U+0061e - U+00612
919          U+0064b - U+0065e
920          U+0074d - U+0076d
921          U+01800 - U+01805
922          U+01d00 - U+01d77
923          U+01d9b - U+01dbf
924          U+0200b - U+0200f
925          U+030fc - U+030fe
926          U+03260 - U+0327f
927          U+0fb46 - U+0fbb1
928          U+10450 - U+1049d
929    
930    12. The -o option (show only the matching part of a line) for pcregrep was not
931        compatible with GNU grep in that, if there was more than one match in a
932        line, it showed only the first of them. It now behaves in the same way as
933        GNU grep.
934    
935    13. If the -o and -v options were combined for pcregrep, it printed a blank
936        line for every non-matching line. GNU grep prints nothing, and pcregrep now
937        does the same. The return code can be used to tell if there were any
938        non-matching lines.
939    
940    14. Added --file-offsets and --line-offsets to pcregrep.
941    
942    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
943        infinitely looping recursion. The bug was that positive lookaheads were not
944        being skipped when checking for a possible empty match (negative lookaheads
945        and both kinds of lookbehind were skipped).
946    
947    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
948        inclusion of <windows.h> to before rather than after the definition of
949        INVALID_FILE_ATTRIBUTES (patch from David Byron).
950    
951    17. Specifying a possessive quantifier with a specific limit for a Unicode
952        character property caused pcre_compile() to compile bad code, which led at
953        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
954        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
955        caused the error; without that there was no problem.
956    
957    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
958    
959    19. Added --enable-pcretest-libreadline.
960    
961    20. In pcrecpp.cc, the variable 'count' was incremented twice in
962        RE::GlobalReplace(). As a result, the number of replacements returned was
963        double what it should be. I removed one of the increments, but Craig sent a
964        later patch that removed the other one (the right fix) and added unit tests
965        that check the return values (which was not done before).
966    
967    21. Several CMake things:
968    
969        (1) Arranged that, when cmake is used on Unix, the libraries end up with
970            the names libpcre and libpcreposix, not just pcre and pcreposix.
971    
972        (2) The above change means that pcretest and pcregrep are now correctly
973            linked with the newly-built libraries, not previously installed ones.
974    
975        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
976    
977    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
978        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
979        UTF-8 newline character). The key issue is that the pattern starts .*;
980        this means that the match must be either at the beginning, or after a
981        newline. The bug was in the code for advancing after a failed match and
982        checking that the new position followed a newline. It was not taking
983        account of UTF-8 characters correctly.
984    
985    23. PCRE was behaving differently from Perl in the way it recognized POSIX
986        character classes. PCRE was not treating the sequence [:...:] as a
987        character class unless the ... were all letters. Perl, however, seems to
988        allow any characters between [: and :], though of course it rejects as
989        unknown any "names" that contain non-letters, because all the known class
990        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
991        for example, whereas PCRE did not - it did not recognize a POSIX character
992        class. This seemed a bit dangerous, so the code has been changed to be
993        closer to Perl. The behaviour is not identical to Perl, because PCRE will
994        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
995        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
996        Perl does, and where it didn't before.
997    
998    24. Rewrite so as to remove the single use of %n from pcregrep because in some
999        Windows environments %n is disabled by default.
1000    
1001    
1002    Version 7.4 21-Sep-07
1003    ---------------------
1004    
1005    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1006        means that a class such as [\s] counted as "explicit reference to CR or
1007        LF". That isn't really right - the whole point of the change was to try to
1008        help when there was an actual mention of one of the two characters. So now
1009        the change happens only if \r or \n (or a literal CR or LF) character is
1010        encountered.
1011    
1012    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1013        of both had grown to the point where there were only 3 bits left.
1014        Fortunately, there was spare space in the data structure, and so I have
1015        moved the internal flags into a new 16-bit field to free up more option
1016        bits.
1017    
1018    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1019        but did not set the internal JCHANGED flag - either of these is enough to
1020        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1021        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1022        start sets both bits.
1023    
1024    4.  Added options (at build time, compile time, exec time) to change \R from
1025        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1026    
1027    5.  doc/pcresyntax.html was missing from the distribution.
1028    
1029    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1030        compatibility, even though it is no longer used.
1031    
1032    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1033        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1034        windows.h file is present (where different names are used). [This was
1035        reversed later after testing - see 16 below.]
1036    
1037    8.  Changed all #include <config.h> to #include "config.h". There were also
1038        some further <pcre.h> cases that I changed to "pcre.h".
1039    
1040    9.  When pcregrep was used with the --colour option, it missed the line ending
1041        sequence off the lines that it output.
1042    
1043    10. It was pointed out to me that arrays of string pointers cause lots of
1044        relocations when a shared library is dynamically loaded. A technique of
1045        using a single long string with a table of offsets can drastically reduce
1046        these. I have refactored PCRE in four places to do this. The result is
1047        dramatic:
1048    
1049          Originally:                          290
1050          After changing UCP table:            187
1051          After changing error message table:   43
1052          After changing table of "verbs"       36
1053          After changing table of Posix names   22
1054    
1055        Thanks to the folks working on Gregex for glib for this insight.
1056    
1057    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1058        unicode-properties was also set.
1059    
1060    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1061    
1062    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1063        checked only for CRLF.
1064    
1065    14. Added casts to pcretest.c to avoid compiler warnings.
1066    
1067    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1068    
1069    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1070        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1071        entirely. This removes changes made in 7 above.
1072    
1073    17. The CMake files have been updated, and there is now more information about
1074        building with CMake in the NON-UNIX-USE document.
1075    
1076    
1077    Version 7.3 28-Aug-07
1078    ---------------------
1079    
1080     1. In the rejigging of the build system that eventually resulted in 7.1, the
1081        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1082        brackets there is not right, since it causes compilers to look for an
1083        installed pcre.h, not the version that is in the source that is being
1084        compiled (which of course may be different). I have changed it back to:
1085    
1086          #include "pcre.h"
1087    
1088        I have a vague recollection that the change was concerned with compiling in
1089        different directories, but in the new build system, that is taken care of
1090        by the VPATH setting the Makefile.
1091    
1092     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1093        when the subject happened to end in the byte 0x85 (e.g. if the last
1094        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1095        characters but of course it shouldn't be taken as a newline when it is part
1096        of another character. The bug was that, for an unlimited repeat of . in
1097        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1098        characters when looking for a newline.
1099    
1100     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1101    
1102     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1103        in debug output.
1104    
1105     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1106        long printing in the pcrecpp unittest when running under MinGW.
1107    
1108     6. ESC_K was left out of the EBCDIC table.
1109    
1110     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1111        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1112        limit also applies to "virtual nesting" when a pattern is recursive, and in
1113        this case 1000 isn't so big. I have been able to remove this limit at the
1114        expense of backing off one optimization in certain circumstances. Normally,
1115        when pcre_exec() would call its internal match() function recursively and
1116        immediately return the result unconditionally, it uses a "tail recursion"
1117        feature to save stack. However, when a subpattern that can match an empty
1118        string has an unlimited repetition quantifier, it no longer makes this
1119        optimization. That gives it a stack frame in which to save the data for
1120        checking that an empty string has been matched. Previously this was taken
1121        from the 1000-entry workspace that had been reserved. So now there is no
1122        explicit limit, but more stack is used.
1123    
1124     8. Applied Daniel's patches to solve problems with the import/export magic
1125        syntax that is required for Windows, and which was going wrong for the
1126        pcreposix and pcrecpp parts of the library. These were overlooked when this
1127        problem was solved for the main library.
1128    
1129     9. There were some crude static tests to avoid integer overflow when computing
1130        the size of patterns that contain repeated groups with explicit upper
1131        limits. As the maximum quantifier is 65535, the maximum group length was
1132        set at 30,000 so that the product of these two numbers did not overflow a
1133        32-bit integer. However, it turns out that people want to use groups that
1134        are longer than 30,000 bytes (though not repeat them that many times).
1135        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1136        made it possible to implement the integer overflow checks in a much more
1137        dynamic way, which I have now done. The artificial limitation on group
1138        length has been removed - we now have only the limit on the total length of
1139        the compiled pattern, which depends on the LINK_SIZE setting.
1140    
1141    10. Fixed a bug in the documentation for get/copy named substring when
1142        duplicate names are permitted. If none of the named substrings are set, the
1143        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1144        empty string.
1145    
1146    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1147        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1148        because the ] is interpreted as the first data character and the
1149        terminating ] is not found. PCRE has been made compatible with Perl in this
1150        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1151        cause memory overwriting.
1152    
1153    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1154        string has been matched (to stop an infinite loop). It was not recognizing
1155        a conditional subpattern that could match an empty string if that
1156        subpattern was within another subpattern. For example, it looped when
1157        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1158        condition was not nested. This bug has been fixed.
1159    
1160    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1161        past the start of the subject in the presence of bytes with the top bit
1162        set, for example "\x8aBCD".
1163    
1164    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1165        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1166    
1167    14. Optimized (?!) to (*FAIL).
1168    
1169    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1170        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1171        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1172        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1173        does: it's just the validity check that is more restrictive.
1174    
1175    16. Inserted checks for integer overflows during escape sequence (backslash)
1176        processing, and also fixed erroneous offset values for syntax errors during
1177        backslash processing.
1178    
1179    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1180        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1181    
1182    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1183        caused an overrun.
1184    
1185    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1186        something other than just ASCII characters) inside a group that had an
1187        unlimited repeat caused a loop at compile time (while checking to see
1188        whether the group could match an empty string).
1189    
1190    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1191        [\P{Any}] did so. (Error in the code for printing property names.)
1192    
1193    21. An orphan \E inside a character class could cause a crash.
1194    
1195    22. A repeated capturing bracket such as (A)? could cause a wild memory
1196        reference during compilation.
1197    
1198    23. There are several functions in pcre_compile() that scan along a compiled
1199        expression for various reasons (e.g. to see if it's fixed length for look
1200        behind). There were bugs in these functions when a repeated \p or \P was
1201        present in the pattern. These operators have additional parameters compared
1202        with \d, etc, and these were not being taken into account when moving along
1203        the compiled data. Specifically:
1204    
1205        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1206            length.
1207    
1208        (b) An item such as \pL+ within a repeated group could cause crashes or
1209            loops.
1210    
1211        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1212            "reference to non-existent subpattern" error.
1213    
1214        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1215    
1216    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1217        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1218    
1219    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1220    
1221    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1222        character were causing crashes (broken optimization).
1223    
1224    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1225        \p or \P) caused a compile-time loop.
1226    
1227    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1228        break. For example, the unstudied pattern [\r\n]A does not match the string
1229        "\r\nA" because change 7.0/46 below moves the current point on by two
1230        characters after failing to match at the start. However, the pattern \nA
1231        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1232        the same is true. There doesn't seem any very clean way out of this, but
1233        what I have chosen to do makes the common cases work: PCRE now takes note
1234        of whether there can be an explicit match for \r or \n anywhere in the
1235        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1236        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1237        pattern has explicit CR or LF references.
1238    
1239    29. Added (*CR) etc for changing newline setting at start of pattern.
1240    
1241    
1242    Version 7.2 19-Jun-07
1243    ---------------------
1244    
1245     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1246        which is apparently normally available under Windows.
1247    
1248     2. Re-jig the pcregrep tests with different newline settings in an attempt
1249        to make them independent of the local environment's newline setting.
1250    
1251     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1252    
1253     4. Some of the "internals" tests were previously cut out when the link size
1254        was not 2, because the output contained actual offsets. The recent new
1255        "Z" feature of pcretest means that these can be cut out, making the tests
1256        usable with all link sizes.
1257    
1258     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1259        stack recursion. This gives a massive performance boost under BSD, but just
1260        a small improvement under Linux. However, it saves one field in the frame
1261        in all cases.
1262    
1263     6. Added more features from the forthcoming Perl 5.10:
1264    
1265        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1266            recursion call. It refers to the nth most recently opened parentheses.
1267    
1268        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1269            to be opened parentheses.
1270    
1271        (c) Conditions that refer to capturing parentheses can be specified
1272            relatively, for example, (?(-2)... or (?(+3)...
1273    
1274        (d) \K resets the start of the current match so that everything before
1275            is not part of it.
1276    
1277        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1278    
1279        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1280            reference syntax.
1281    
1282        (g) (?| introduces a group in which the numbering of parentheses in each
1283            alternative starts with the same number.
1284    
1285        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1286    
1287     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1288        PCRE_INFO_JCHANGED.
1289    
1290     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1291        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1292        for detecting groups that can match an empty string.
1293    
1294     9. A pattern with a very large number of alternatives (more than several
1295        hundred) was running out of internal workspace during the pre-compile
1296        phase, where pcre_compile() figures out how much memory will be needed. A
1297        bit of new cunning has reduced the workspace needed for groups with
1298        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1299        workspace instead of running out of the 4096 that are available.
1300    
1301    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1302    
1303    11. Applied patch from Google to remove an optimization that didn't quite work.
1304        The report of the bug said:
1305    
1306          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1307          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1308          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1309    
1310    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1311        it matched the wrong number of bytes.
1312    
1313    
1314    Version 7.1 24-Apr-07
1315    ---------------------
1316    
1317     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1318        that is more "standard", making use of automake and other Autotools. There
1319      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
1320      on this.      on this.
1321    
1322   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1323      for recursive directory scanning broke on some systems because the files      for recursive directory scanning broke on some systems because the files
1324      are not scanned in any specific order and on different systems the order      are not scanned in any specific order and on different systems the order
1325      was different. A call to "sort" has been inserted into RunGrepTest for the      was different. A call to "sort" has been inserted into RunGrepTest for the
1326      approprate test as a short-term fix. In the longer term there may be an      approprate test as a short-term fix. In the longer term there may be an
1327      alternative.      alternative.
1328    
1329   3. I had an email from Eric Raymond about problems translating some of PCRE's   3. I had an email from Eric Raymond about problems translating some of PCRE's
1330      man pages to HTML (despite the fact that I distribute HTML pages, some      man pages to HTML (despite the fact that I distribute HTML pages, some
1331      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
1332      concerned the use of low-level troff macros .br and .in. I have therefore      concerned the use of low-level troff macros .br and .in. I have therefore
1333      removed all such uses from the man pages (some were redundant, some could      removed all such uses from the man pages (some were redundant, some could
1334      be replaced by .nf/.fi pairs). The maintain/132html script that I use to      be replaced by .nf/.fi pairs). The 132html script that I use to generate
1335      generate HTML has been updated to handle .nf/.fi and to complain if it      HTML has been updated to handle .nf/.fi and to complain if it encounters
1336      encounters .br or .in.      .br or .in.
1337    
1338   4. Updated comments in configure.ac that get placed in config.h.in and also   4. Updated comments in configure.ac that get placed in config.h.in and also
1339      arranged for config.h to be included in the distribution, for the benefit      arranged for config.h to be included in the distribution, with the name
1340      of those who have to compile without Autotools (compare pcre.h).      config.h.generic, for the benefit of those who have to compile without
1341        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1342   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan  
1343      Weber: (1) pcre_internal.h was missing some function renames; (2) updated   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1344      makevp.bat for the current PCRE, using the additional files !compile.txt,      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1345      !linklib.txt, and pcregexp.pas.      makevp.bat for the current PCRE, using the additional files
1346        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1347   6. A Windows user reported a minor discrepancy with test 2, which turned out  
1348      to be caused by a trailing space on an input line that had got lost in his   6. A Windows user reported a minor discrepancy with test 2, which turned out
1349        to be caused by a trailing space on an input line that had got lost in his
1350      copy. The trailing space was an accident, so I've just removed it.      copy. The trailing space was an accident, so I've just removed it.
1351    
1352   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1353      that is needed.      that is needed.
1354    
1355   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1356      as "const" (a) because they are and (b) because it helps the PHP      as "const" (a) because they are and (b) because it helps the PHP
1357      maintainers who have recently made a script to detect big data structures      maintainers who have recently made a script to detect big data structures
1358      in the php code that should be moved to the .rodata section. I remembered      in the php code that should be moved to the .rodata section. I remembered
1359      to update Builducptable as well, so it won't revert if ucptable.h is ever      to update Builducptable as well, so it won't revert if ucptable.h is ever
1360      re-created.      re-created.
1361    
1362     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1363        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1364        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1365        support is not required. This saves 1.5-2K of code, which is important in
1366        some applications.
1367    
1368        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1369        so as not to refer to the tables, even though these functions will never be
1370        called when UTF-8 support is disabled. Otherwise there are problems with a
1371        shared library.
1372    
1373    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1374    
1375        (a) It was defining its arguments as char * instead of void *.
1376    
1377        (b) It was assuming that all moves were upwards in memory; this was true
1378            a long time ago when I wrote it, but is no longer the case.
1379    
1380        The emulated memove() is provided for those environments that have neither
1381        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1382        is clearly not the case, as these two bugs were recently reported.
1383    
1384    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1385        and Detrail to create the HTML documentation, the .txt form of the man
1386        pages, and it removes trailing spaces from listed files. It also creates
1387        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1388        case, it wraps all the #defines with #ifndefs. This script should be run
1389        before "make dist".
1390    
1391    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1392        with Unicode property support.
1393    
1394        (a) For a maximizing quantifier, if the two different cases of the
1395            character were of different lengths in their UTF-8 codings (there are
1396            some cases like this - I found 11), and the matching function had to
1397            back up over a mixture of the two cases, it incorrectly assumed they
1398            were both the same length.
1399    
1400        (b) When PCRE was configured to use the heap rather than the stack for
1401            recursion during matching, it was not correctly preserving the data for
1402            the other case of a UTF-8 character when checking ahead for a match
1403            while processing a minimizing repeat. If the check also involved
1404            matching a wide character, but failed, corruption could cause an
1405            erroneous result when trying to check for a repeat of the original
1406            character.
1407    
1408    13. Some tidying changes to the testing mechanism:
1409    
1410        (a) The RunTest script now detects the internal link size and whether there
1411            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1412            values substituted by "configure". (The RunGrepTest script already did
1413            this for UTF-8.) The configure.ac script no longer substitutes the
1414            relevant variables.
1415    
1416        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1417            with length and offset values. This means that the output is different
1418            for different internal link sizes. Test 2 is skipped for link sizes
1419            other than 2 because of this, bypassing the problem. Unfortunately,
1420            there was also a test in test 3 (the locale tests) that used /B and
1421            failed for link sizes other than 2. Rather than cut the whole test out,
1422            I have added a new /Z option to pcretest that replaces the length and
1423            offset values with spaces. This is now used to make test 3 independent
1424            of link size. (Test 2 will be tidied up later.)
1425    
1426    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1427        segmentation fault instead of returning the appropriate error message.
1428    
1429    15. In multiline mode when the newline sequence was set to "any", the pattern
1430        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1431        This doesn't seem right; it now treats the CRLF combination as the line
1432        ending, and so does not match in that case. It's only a pattern such as ^$
1433        that would hit this one: something like ^ABC$ would have failed after \r
1434        and then tried again after \r\n.
1435    
1436    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1437        in an attempt to make files that differ only in their line terminators
1438        compare equal. This works on Linux.
1439    
1440    17. Under certain error circumstances pcregrep might try to free random memory
1441        as it exited. This is now fixed, thanks to valgrind.
1442    
1443    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1444        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1445        was because its rules for how to advance for /g after matching an empty
1446        string at the end of a line did not allow for this case. They now check for
1447        it specially.
1448    
1449    20. pcretest is supposed to handle patterns and data of any length, by
1450        extending its buffers when necessary. It was getting this wrong when the
1451        buffer for a data line had to be extended.
1452    
1453    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1454        CRLF as a newline sequence.
1455    
1456    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1457        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1458        I have nevertheless tidied it up.
1459    
1460    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1461    
1462    24. Added a man page for pcre-config.
1463    
1464    
1465  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1466  ---------------------  ---------------------

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