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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.0 02 Jul-08  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    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58        cater for a lack of strerror(). These oversights have been fixed.
59    
60    9.  Added --match-limit and --recursion-limit to pcregrep.
61    
62    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63    
64    11. When the -o option was used, pcregrep was setting a return code of 1, even
65        when matches were found, and --line-buffered was not being honoured.
66    
67    12. Added an optional parentheses number to the -o and --only-matching options
68        of pcregrep.
69    
70    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
71        can match an empty string. The code to do it in pcretest and pcredemo
72        needed fixing:
73    
74        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
75            only one byte after an empty string match just before CRLF (this case
76            just got forgotten; "any" and "anycrlf" were OK).
77    
78        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
79            mode when an empty string match preceded an ASCII character followed by
80            a non-ASCII character. (The code for advancing by one character rather
81            than one byte was nonsense.)
82    
83        (c) The pcredemo.c sample program did not have any code at all to handle
84            the cases when CRLF is a valid newline sequence.
85    
86    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
87        as a starting offset was within the subject string. There is now a new
88        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
89        negative or greater than the length of the string. In order to test this,
90        pcretest is extended to allow the setting of negative starting offsets.
91    
92    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
93        starting offset points to the beginning of a UTF-8 character was
94        unnecessarily clumsy. I tidied it up.
95    
96    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
97        bad UTF-8 sequence and one that is incomplete.
98    
99    17. Nobody had reported that the --include_dir option, which was added in
100        release 7.7 should have been called --include-dir (hyphen, not underscore)
101        for compatibility with GNU grep. I have changed it to --include-dir, but
102        left --include_dir as an undocumented synonym, and the same for
103        --exclude-dir, though that is not available in GNU grep, at least as of
104        release 2.5.4.
105    
106    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
107        characters from a string of bytes) have been redefined so as not to use
108        loops, in order to improve performance in some environments. At the same
109        time, I abstracted some of the common code into auxiliary macros to save
110        repetition (this should not affect the compiled code).
111    
112    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
113        compile-time error is now given if \c is not followed by an ASCII
114        character, that is, a byte less than 128. (In EBCDIC mode, the code is
115        different, and any byte value is allowed.)
116    
117    
118    Version 8.10 25-Jun-2010
119    ------------------------
120    
121    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
122        THEN.
123    
124    2.  (*ACCEPT) was not working when inside an atomic group.
125    
126    3.  Inside a character class, \B is treated as a literal by default, but
127        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
128        causes the error). The code is unchanged, but I tidied the documentation.
129    
130    4.  Inside a character class, PCRE always treated \R and \X as literals,
131        whereas Perl faults them if its -w option is set. I have changed PCRE so
132        that it faults them when PCRE_EXTRA is set.
133    
134    5.  Added support for \N, which always matches any character other than
135        newline. (It is the same as "." when PCRE_DOTALL is not set.)
136    
137    6.  When compiling pcregrep with newer versions of gcc which may have
138        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
139        declared with attribute warn_unused_result" were given. Just casting the
140        result to (void) does not stop the warnings; a more elaborate fudge is
141        needed. I've used a macro to implement this.
142    
143    7.  Minor change to pcretest.c to avoid a compiler warning.
144    
145    8.  Added four artifical Unicode properties to help with an option to make
146        \s etc use properties (see next item). The new properties are: Xan
147        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
148    
149    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
150        use Unicode properties. (*UCP) at the start of a pattern can be used to set
151        this option. Modified pcretest to add /W to test this facility. Added
152        REG_UCP to make it available via the POSIX interface.
153    
154    10. Added --line-buffered to pcregrep.
155    
156    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
157        studied, and the match started with a letter with a code point greater than
158        127 whose first byte was different to the first byte of the other case of
159        the letter, the other case of this starting letter was not recognized
160        (#976).
161    
162    12. If a pattern that was studied started with a repeated Unicode property
163        test, for example, \p{Nd}+, there was the theoretical possibility of
164        setting up an incorrect bitmap of starting bytes, but fortunately it could
165        not have actually happened in practice until change 8 above was made (it
166        added property types that matched character-matching opcodes).
167    
168    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
169        possible starting bytes for non-anchored patterns.
170    
171    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
172        \R, and also a number of cases that involve Unicode properties, both
173        explicit and implicit when PCRE_UCP is set.
174    
175    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
176        input, it could crash or give wrong results if characters with values
177        greater than 0xc0 were present in the subject string. (Detail: it assumed
178        UTF-8 input when processing these items.)
179    
180    16. Added a lot of (int) casts to avoid compiler warnings in systems where
181        size_t is 64-bit (#991).
182    
183    17. Added a check for running out of memory when PCRE is compiled with
184        --disable-stack-for-recursion (#990).
185    
186    18. If the last data line in a file for pcretest does not have a newline on
187        the end, a newline was missing in the output.
188    
189    19. The default pcre_chartables.c file recognizes only ASCII characters (values
190        less than 128) in its various bitmaps. However, there is a facility for
191        generating tables according to the current locale when PCRE is compiled. It
192        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
193        characters, are recognized by isspace() and therefore were getting set in
194        these tables, and indeed these tables seem to approximate to ISO 8859. This
195        caused a problem in UTF-8 mode when pcre_study() was used to create a list
196        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
197        which of course cannot start UTF-8 characters. I have changed the code so
198        that only real ASCII characters (less than 128) and the correct starting
199        bytes for UTF-8 encodings are set for characters greater than 127 when in
200        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
201        altogether.)
202    
203    20. Added the /T option to pcretest so as to be able to run tests with non-
204        standard character tables, thus making it possible to include the tests
205        used for 19 above in the standard set of tests.
206    
207    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
208        reference to a subpattern the other side of a comment that contains an
209        opening parenthesis caused either an internal compiling error, or a
210        reference to the wrong subpattern.
211    
212    
213    Version 8.02 19-Mar-2010
214    ------------------------
215    
216    1.  The Unicode data tables have been updated to Unicode 5.2.0.
217    
218    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
219        configured.
220    
221    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
222        original author of that file, following a query about its status.
223    
224    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
225        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
226    
227    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
228        quantifier applied to a forward-referencing subroutine call, could compile
229        incorrect code or give the error "internal error: previously-checked
230        referenced subpattern not found".
231    
232    6.  Both MS Visual Studio and Symbian OS have problems with initializing
233        variables to point to external functions. For these systems, therefore,
234        pcre_malloc etc. are now initialized to local functions that call the
235        relevant global functions.
236    
237    7.  There were two entries missing in the vectors called coptable and poptable
238        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
239        I've fixed the data, and added a kludgy way of testing at compile time that
240        the lengths are correct (equal to the number of opcodes).
241    
242    8.  Following on from 7, I added a similar kludge to check the length of the
243        eint vector in pcreposix.c.
244    
245    9.  Error texts for pcre_compile() are held as one long string to avoid too
246        much relocation at load time. To find a text, the string is searched,
247        counting zeros. There was no check for running off the end of the string,
248        which could happen if a new error number was added without updating the
249        string.
250    
251    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
252    
253    11. \K was not working if it appeared in an atomic group or in a group that
254        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
255        \K is "not well defined" if used in an assertion. PCRE now accepts it if
256        the assertion is positive, but not if it is negative.
257    
258    12. Change 11 fortuitously reduced the size of the stack frame used in the
259        "match()" function of pcre_exec.c by one pointer. Forthcoming
260        implementation of support for (*MARK) will need an extra pointer on the
261        stack; I have reserved it now, so that the stack frame size does not
262        decrease.
263    
264    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
265        item in branch that calls a recursion is a subroutine call - as in the
266        second branch in the above example - was incorrectly given the compile-
267        time error "recursive call could loop indefinitely" because pcre_compile()
268        was not correctly checking the subroutine for matching a non-empty string.
269    
270    14. The checks for overrunning compiling workspace could trigger after an
271        overrun had occurred. This is a "should never occur" error, but it can be
272        triggered by pathological patterns such as hundreds of nested parentheses.
273        The checks now trigger 100 bytes before the end of the workspace.
274    
275    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
276    
277    
278    Version 8.01 19-Jan-2010
279    ------------------------
280    
281    1.  If a pattern contained a conditional subpattern with only one branch (in
282        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
283        computed the wrong minimum data length (which is of course zero for such
284        subpatterns). This could cause incorrect "no match" results.
285    
286    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
287        the pattern is reset in the first branch, pcre_compile() failed with
288        "internal error: code overflow at offset...". This happened only when
289        the reset was to the original external option setting. (An optimization
290        abstracts leading options settings into an external setting, which was the
291        cause of this.)
292    
293    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
294        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
295        assertion pattern did not match (meaning that the assertion was true), it
296        was incorrectly treated as false if the SKIP had been reached during the
297        matching. This also applied to assertions used as conditions.
298    
299    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
300        assertion subpattern, including such a pattern used as a condition,
301        unpredictable results occurred, instead of the error return
302        PCRE_ERROR_DFA_UITEM.
303    
304    5.  The C++ GlobalReplace function was not working like Perl for the special
305        situation when an empty string is matched. It now does the fancy magic
306        stuff that is necessary.
307    
308    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
309        removed. (These were left over from very, very early versions of PCRE.)
310    
311    7.  Some cosmetic changes to the code to make life easier when compiling it
312        as part of something else:
313    
314        (a) Change DEBUG to PCRE_DEBUG.
315    
316        (b) In pcre_compile(), rename the member of the "branch_chain" structure
317            called "current" as "current_branch", to prevent a collision with the
318            Linux macro when compiled as a kernel module.
319    
320        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
321            prevent a collision with the Linux macro when compiled as a kernel
322            module.
323    
324    8.  In pcre_compile() there are some checks for integer overflows that used to
325        cast potentially large values to (double). This has been changed to that
326        when building, a check for int64_t is made, and if it is found, it is used
327        instead, thus avoiding the use of floating point arithmetic. (There is no
328        other use of FP in PCRE.) If int64_t is not found, the fallback is to
329        double.
330    
331    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
332        2005 (difference between two addresses compared to an unsigned value).
333    
334    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
335        custom one, because of the following reported problem in Windows:
336    
337          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
338              under Win32.
339          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
340              therefore missing the function definition.
341          - The compiler thus generates a "C" signature for the test function.
342          - The linker fails to find the "C" function.
343          - PCRE fails to configure if asked to do so against libbz2.
344    
345    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
346        messages were output:
347    
348          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
349          rerunning libtoolize, to keep the correct libtool macros in-tree.
350          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
351    
352        I have done both of these things.
353    
354    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
355        most of the time, it *can* run out if it is given a pattern that contains a
356        runaway infinite recursion. I updated the discussion in the pcrestack man
357        page.
358    
359    13. Now that we have gone to the x.xx style of version numbers, the minor
360        version may start with zero. Using 08 or 09 is a bad idea because users
361        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
362        interpreted as invalid octal numbers. I've updated the previous comment in
363        configure.ac, and also added a check that gives an error if 08 or 09 are
364        used.
365    
366    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
367        causing partial matching to fail when the end of the subject matched \W
368        in a UTF-8 pattern where \W was quantified with a minimum of 3.
369    
370    15. There were some discrepancies between the declarations in pcre_internal.h
371        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
372        their definitions. The declarations used "const uschar *" and the
373        definitions used USPTR. Even though USPTR is normally defined as "const
374        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
375        reported that: "This difference in casting confuses some C++ compilers, for
376        example, SunCC recognizes above declarations as different functions and
377        generates broken code for hbpcre." I have changed the declarations to use
378        USPTR.
379    
380    16. GNU libtool is named differently on some systems. The autogen.sh script now
381        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
382        (FreeBSD).
383    
384    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
385        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
386        comment: "Figure out how to create a longlong from a string: strtoll and
387        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
388        instance, but it only takes 2 args instead of 3!"
389    
390    18. A subtle bug concerned with back references has been fixed by a change of
391        specification, with a corresponding code fix. A pattern such as
392        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
393        refers, was giving matches when it shouldn't. For example, xa=xaaa would
394        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
395        same bug. Such groups have to be quantified to be useful, or contained
396        inside another quantified group. (If there's no repetition, the reference
397        can never match.) The problem arises because, having left the group and
398        moved on to the rest of the pattern, a later failure that backtracks into
399        the group uses the captured value from the final iteration of the group
400        rather than the correct earlier one. I have fixed this in PCRE by forcing
401        any group that contains a reference to itself to be an atomic group; that
402        is, there cannot be any backtracking into it once it has completed. This is
403        similar to recursive and subroutine calls.
404    
405    
406    Version 8.00 19-Oct-09
407    ----------------------
408    
409    1.  The table for translating pcre_compile() error codes into POSIX error codes
410        was out-of-date, and there was no check on the pcre_compile() error code
411        being within the table. This could lead to an OK return being given in
412        error.
413    
414    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
415        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
416        in a Windows environment.
417    
418    3.  The pcregrep --count option prints the count for each file even when it is
419        zero, as does GNU grep. However, pcregrep was also printing all files when
420        --files-with-matches was added. Now, when both options are given, it prints
421        counts only for those files that have at least one match. (GNU grep just
422        prints the file name in this circumstance, but including the count seems
423        more useful - otherwise, why use --count?) Also ensured that the
424        combination -clh just lists non-zero counts, with no names.
425    
426    4.  The long form of the pcregrep -F option was incorrectly implemented as
427        --fixed_strings instead of --fixed-strings. This is an incompatible change,
428        but it seems right to fix it, and I didn't think it was worth preserving
429        the old behaviour.
430    
431    5.  The command line items --regex=pattern and --regexp=pattern were not
432        recognized by pcregrep, which required --regex pattern or --regexp pattern
433        (with a space rather than an '='). The man page documented the '=' forms,
434        which are compatible with GNU grep; these now work.
435    
436    6.  No libpcreposix.pc file was created for pkg-config; there was just
437        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
438    
439    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
440        when UCP support is not needed, by modifying the Python script that
441        generates it from Unicode data files. This should not matter if the module
442        is correctly used as a library, but I received one complaint about 50K of
443        unwanted data. My guess is that the person linked everything into his
444        program rather than using a library. Anyway, it does no harm.
445    
446    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
447        was a minimum greater than 1 for a wide character in a possessive
448        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
449        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
450        character. Chaos in the form of incorrect output or a compiling loop could
451        result.
452    
453    9.  The restrictions on what a pattern can contain when partial matching is
454        requested for pcre_exec() have been removed. All patterns can now be
455        partially matched by this function. In addition, if there are at least two
456        slots in the offset vector, the offset of the earliest inspected character
457        for the match and the offset of the end of the subject are set in them when
458        PCRE_ERROR_PARTIAL is returned.
459    
460    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
461        synonymous with PCRE_PARTIAL, for backwards compatibility, and
462        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
463        and may be more useful for multi-segment matching.
464    
465    11. Partial matching with pcre_exec() is now more intuitive. A partial match
466        used to be given if ever the end of the subject was reached; now it is
467        given only if matching could not proceed because another character was
468        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
469        string "Z", which now yields "no match" instead of "partial match". In the
470        case of pcre_dfa_exec(), "no match" is given if every matching path for the
471        final character ended with (*FAIL).
472    
473    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
474        if the pattern had a "must contain" character that was already found in the
475        earlier partial match, unless partial matching was again requested. For
476        example, with the pattern /dog.(body)?/, the "must contain" character is
477        "g". If the first part-match was for the string "dog", restarting with
478        "sbody" failed. This bug has been fixed.
479    
480    13. The string returned by pcre_dfa_exec() after a partial match has been
481        changed so that it starts at the first inspected character rather than the
482        first character of the match. This makes a difference only if the pattern
483        starts with a lookbehind assertion or \b or \B (\K is not supported by
484        pcre_dfa_exec()). It's an incompatible change, but it makes the two
485        matching functions compatible, and I think it's the right thing to do.
486    
487    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
488        so that the demonstration program is easily available in environments where
489        PCRE has not been installed from source.
490    
491    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
492        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
493        library.
494    
495    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
496        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
497        is not the first non-POSIX option to be added. Clearly some people find
498        these options useful.
499    
500    17. If a caller to the POSIX matching function regexec() passes a non-zero
501        value for nmatch with a NULL value for pmatch, the value of
502        nmatch is forced to zero.
503    
504    18. RunGrepTest did not have a test for the availability of the -u option of
505        the diff command, as RunTest does. It now checks in the same way as
506        RunTest, and also checks for the -b option.
507    
508    19. If an odd number of negated classes containing just a single character
509        interposed, within parentheses, between a forward reference to a named
510        subpattern and the definition of the subpattern, compilation crashed with
511        an internal error, complaining that it could not find the referenced
512        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
513        [The bug was that it was starting one character too far in when skipping
514        over the character class, thus treating the ] as data rather than
515        terminating the class. This meant it could skip too much.]
516    
517    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
518        /g option in pcretest when the pattern contains \K, which makes it possible
519        to have an empty string match not at the start, even when the pattern is
520        anchored. Updated pcretest and pcredemo to use this option.
521    
522    21. If the maximum number of capturing subpatterns in a recursion was greater
523        than the maximum at the outer level, the higher number was returned, but
524        with unset values at the outer level. The correct (outer level) value is
525        now given.
526    
527    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
528        PCRE did not set those parentheses (unlike Perl). I have now found a way to
529        make it do so. The string so far is captured, making this feature
530        compatible with Perl.
531    
532    23. The tests have been re-organized, adding tests 11 and 12, to make it
533        possible to check the Perl 5.10 features against Perl 5.10.
534    
535    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
536        pattern matches a fixed length string. PCRE did not allow this; now it
537        does. Neither allows recursion.
538    
539    25. I finally figured out how to implement a request to provide the minimum
540        length of subject string that was needed in order to match a given pattern.
541        (It was back references and recursion that I had previously got hung up
542        on.) This code has now been added to pcre_study(); it finds a lower bound
543        to the length of subject needed. It is not necessarily the greatest lower
544        bound, but using it to avoid searching strings that are too short does give
545        some useful speed-ups. The value is available to calling programs via
546        pcre_fullinfo().
547    
548    26. While implementing 25, I discovered to my embarrassment that pcretest had
549        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
550        study optimizations had never been tested with that matching function.
551        Oops. What is worse, even when it was passed study data, there was a bug in
552        pcre_dfa_exec() that meant it never actually used it. Double oops. There
553        were also very few tests of studied patterns with pcre_dfa_exec().
554    
555    27. If (?| is used to create subpatterns with duplicate numbers, they are now
556        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
557        on the other side of the coin, they are no longer allowed to have different
558        names, because these cannot be distinguished in PCRE, and this has caused
559        confusion. (This is a difference from Perl.)
560    
561    28. When duplicate subpattern names are present (necessarily with different
562        numbers, as required by 27 above), and a test is made by name in a
563        conditional pattern, either for a subpattern having been matched, or for
564        recursion in such a pattern, all the associated numbered subpatterns are
565        tested, and the overall condition is true if the condition is true for any
566        one of them. This is the way Perl works, and is also more like the way
567        testing by number works.
568    
569    
570    Version 7.9 11-Apr-09
571    ---------------------
572    
573    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
574        (pcretest), all targets were linked against these libraries. This included
575        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
576        libraries. This caused unwanted dependencies to be created. This problem
577        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
578        pcretest is linked with readline.
579    
580    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
581        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
582        moved outside it again, because FALSE and TRUE are already defined in AIX,
583        but BOOL is not.
584    
585    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
586        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
587    
588    4.  The pcregrep documentation said spaces were inserted as well as colons (or
589        hyphens) following file names and line numbers when outputting matching
590        lines. This is not true; no spaces are inserted. I have also clarified the
591        wording for the --colour (or --color) option.
592    
593    5.  In pcregrep, when --colour was used with -o, the list of matching strings
594        was not coloured; this is different to GNU grep, so I have changed it to be
595        the same.
596    
597    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
598        each matching line was coloured. Now it goes on to look for further matches
599        of any of the test patterns, which is the same behaviour as GNU grep.
600    
601    7.  A pattern that could match an empty string could cause pcregrep to loop; it
602        doesn't make sense to accept an empty string match in pcregrep, so I have
603        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
604        seems to be how GNU grep behaves.
605    
606    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
607        start or after a newline", because the conditional assertion was not being
608        correctly handled. The rule now is that both the assertion and what follows
609        in the first alternative must satisfy the test.
610    
611    9.  If auto-callout was enabled in a pattern with a conditional group whose
612        condition was an assertion, PCRE could crash during matching, both with
613        pcre_exec() and pcre_dfa_exec().
614    
615    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
616        used for matching.
617    
618    11. Unicode property support in character classes was not working for
619        characters (bytes) greater than 127 when not in UTF-8 mode.
620    
621    12. Added the -M command line option to pcretest.
622    
623    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
624    
625    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
626    
627    16. Added comments and documentation about mis-use of no_arg in the C++
628        wrapper.
629    
630    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
631        from Martin Jerabek that uses macro names for all relevant character and
632        string constants.
633    
634    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
635        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
636        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
637        these, but not everybody uses configure.
638    
639    19. A conditional group that had only one branch was not being correctly
640        recognized as an item that could match an empty string. This meant that an
641        enclosing group might also not be so recognized, causing infinite looping
642        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
643        with the subject "ab", where knowledge that the repeated group can match
644        nothing is needed in order to break the loop.
645    
646    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
647        exec(), but without supplying a callout function, matching went wrong.
648    
649    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
650        leak if the size of the offset vector was greater than 30. When the vector
651        is smaller, the saved offsets during recursion go onto a local stack
652        vector, but for larger vectors malloc() is used. It was failing to free
653        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
654        error, in fact).
655    
656    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
657        heapframe that is used only when UTF-8 support is enabled. This caused no
658        problem, but was untidy.
659    
660    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
661        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
662        included within another project.
663    
664    24. Steven Van Ingelgem's patches to add more options to the CMake support,
665        slightly modified by me:
666    
667          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
668              not building pcregrep.
669    
670          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
671              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
672    
673    25. Forward references, both numeric and by name, in patterns that made use of
674        duplicate group numbers, could behave incorrectly or give incorrect errors,
675        because when scanning forward to find the reference group, PCRE was not
676        taking into account the duplicate group numbers. A pattern such as
677        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
678    
679    26. Changed a few more instances of "const unsigned char *" to USPTR, making
680        the feature of a custom pointer more persuasive (as requested by a user).
681    
682    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
683        pcretest.c, inside #ifndefs, because it seems they are sometimes already
684        pre-defined.
685    
686    28. Added support for (*UTF8) at the start of a pattern.
687    
688    29. Arrange for flags added by the "release type" setting in CMake to be shown
689        in the configuration summary.
690    
691    
692    Version 7.8 05-Sep-08
693  ---------------------  ---------------------
694    
695  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
# Line 31  Version 8.0 02 Jul-08 Line 719  Version 8.0 02 Jul-08
719    
720  7.  Added two (int) casts to pcregrep when printing the difference of two  7.  Added two (int) casts to pcregrep when printing the difference of two
721      pointers, in case they are 64-bit values.      pointers, in case they are 64-bit values.
722    
723  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
724      test 2 if it fails.      test 2 if it fails.
725    
726  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
727      and a #define of that name to empty if it is not externally set. This is to      and a #define of that name to empty if it is not externally set. This is to
728      allow users of MSVC to set it if necessary.      allow users of MSVC to set it if necessary.
729    
730  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
731      the convenience functions in the pcre_get.c source file.      the convenience functions in the pcre_get.c source file.
732    
733  11. An option change at the start of a pattern that had top-level alternatives  11. An option change at the start of a pattern that had top-level alternatives
734      could cause overwriting and/or a crash. This command provoked a crash in      could cause overwriting and/or a crash. This command provoked a crash in
735      some environments:      some environments:
736    
737        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
738    
739      This potential security problem was recorded as CVE-2008-2371.      This potential security problem was recorded as CVE-2008-2371.
740    
741    12. For a pattern where the match had to start at the beginning or immediately
742        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
743        pcre_dfa_exec() could read past the end of the passed subject if there was
744        no match. To help with detecting such bugs (e.g. with valgrind), I modified
745        pcretest so that it places the subject at the end of its malloc-ed buffer.
746    
747    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
748        exec() might read past the end of the data buffer in UTF-8 mode.
749    
750    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
751        the data contained the byte 0x85 as part of a UTF-8 character within its
752        first line. This applied both to normal and DFA matching.
753    
754    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
755        /^[^d]*?$/8 failed to match "abc".
756    
757    16. Added a missing copyright notice to pcrecpp_internal.h.
758    
759    17. Make it more clear in the documentation that values returned from
760        pcre_exec() in ovector are byte offsets, not character counts.
761    
762    18. Tidied a few places to stop certain compilers from issuing warnings.
763    
764    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
765        supplied by Stefan Weber. I made a further small update for 7.8 because
766        there is a change of source arrangements: the pcre_searchfuncs.c module is
767        replaced by pcre_ucd.c.
768    
769    
770  Version 7.7 07-May-08  Version 7.7 07-May-08
771  ---------------------  ---------------------

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