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

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