/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 96 by nigel, Fri Mar 2 13:10:43 2007 UTC revision 573 by ph10, Fri Nov 19 19:29:44 2010 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    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    
113    Version 8.10 25-Jun-2010
114    ------------------------
115    
116    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
117        THEN.
118    
119    2.  (*ACCEPT) was not working when inside an atomic group.
120    
121    3.  Inside a character class, \B is treated as a literal by default, but
122        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
123        causes the error). The code is unchanged, but I tidied the documentation.
124    
125    4.  Inside a character class, PCRE always treated \R and \X as literals,
126        whereas Perl faults them if its -w option is set. I have changed PCRE so
127        that it faults them when PCRE_EXTRA is set.
128    
129    5.  Added support for \N, which always matches any character other than
130        newline. (It is the same as "." when PCRE_DOTALL is not set.)
131    
132    6.  When compiling pcregrep with newer versions of gcc which may have
133        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
134        declared with attribute warn_unused_result" were given. Just casting the
135        result to (void) does not stop the warnings; a more elaborate fudge is
136        needed. I've used a macro to implement this.
137    
138    7.  Minor change to pcretest.c to avoid a compiler warning.
139    
140    8.  Added four artifical Unicode properties to help with an option to make
141        \s etc use properties (see next item). The new properties are: Xan
142        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
143    
144    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
145        use Unicode properties. (*UCP) at the start of a pattern can be used to set
146        this option. Modified pcretest to add /W to test this facility. Added
147        REG_UCP to make it available via the POSIX interface.
148    
149    10. Added --line-buffered to pcregrep.
150    
151    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
152        studied, and the match started with a letter with a code point greater than
153        127 whose first byte was different to the first byte of the other case of
154        the letter, the other case of this starting letter was not recognized
155        (#976).
156    
157    12. If a pattern that was studied started with a repeated Unicode property
158        test, for example, \p{Nd}+, there was the theoretical possibility of
159        setting up an incorrect bitmap of starting bytes, but fortunately it could
160        not have actually happened in practice until change 8 above was made (it
161        added property types that matched character-matching opcodes).
162    
163    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
164        possible starting bytes for non-anchored patterns.
165    
166    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
167        \R, and also a number of cases that involve Unicode properties, both
168        explicit and implicit when PCRE_UCP is set.
169    
170    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
171        input, it could crash or give wrong results if characters with values
172        greater than 0xc0 were present in the subject string. (Detail: it assumed
173        UTF-8 input when processing these items.)
174    
175    16. Added a lot of (int) casts to avoid compiler warnings in systems where
176        size_t is 64-bit (#991).
177    
178    17. Added a check for running out of memory when PCRE is compiled with
179        --disable-stack-for-recursion (#990).
180    
181    18. If the last data line in a file for pcretest does not have a newline on
182        the end, a newline was missing in the output.
183    
184    19. The default pcre_chartables.c file recognizes only ASCII characters (values
185        less than 128) in its various bitmaps. However, there is a facility for
186        generating tables according to the current locale when PCRE is compiled. It
187        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
188        characters, are recognized by isspace() and therefore were getting set in
189        these tables, and indeed these tables seem to approximate to ISO 8859. This
190        caused a problem in UTF-8 mode when pcre_study() was used to create a list
191        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
192        which of course cannot start UTF-8 characters. I have changed the code so
193        that only real ASCII characters (less than 128) and the correct starting
194        bytes for UTF-8 encodings are set for characters greater than 127 when in
195        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
196        altogether.)
197    
198    20. Added the /T option to pcretest so as to be able to run tests with non-
199        standard character tables, thus making it possible to include the tests
200        used for 19 above in the standard set of tests.
201    
202    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
203        reference to a subpattern the other side of a comment that contains an
204        opening parenthesis caused either an internal compiling error, or a
205        reference to the wrong subpattern.
206    
207    
208    Version 8.02 19-Mar-2010
209    ------------------------
210    
211    1.  The Unicode data tables have been updated to Unicode 5.2.0.
212    
213    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
214        configured.
215    
216    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
217        original author of that file, following a query about its status.
218    
219    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
220        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
221    
222    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
223        quantifier applied to a forward-referencing subroutine call, could compile
224        incorrect code or give the error "internal error: previously-checked
225        referenced subpattern not found".
226    
227    6.  Both MS Visual Studio and Symbian OS have problems with initializing
228        variables to point to external functions. For these systems, therefore,
229        pcre_malloc etc. are now initialized to local functions that call the
230        relevant global functions.
231    
232    7.  There were two entries missing in the vectors called coptable and poptable
233        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
234        I've fixed the data, and added a kludgy way of testing at compile time that
235        the lengths are correct (equal to the number of opcodes).
236    
237    8.  Following on from 7, I added a similar kludge to check the length of the
238        eint vector in pcreposix.c.
239    
240    9.  Error texts for pcre_compile() are held as one long string to avoid too
241        much relocation at load time. To find a text, the string is searched,
242        counting zeros. There was no check for running off the end of the string,
243        which could happen if a new error number was added without updating the
244        string.
245    
246    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
247    
248    11. \K was not working if it appeared in an atomic group or in a group that
249        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
250        \K is "not well defined" if used in an assertion. PCRE now accepts it if
251        the assertion is positive, but not if it is negative.
252    
253    12. Change 11 fortuitously reduced the size of the stack frame used in the
254        "match()" function of pcre_exec.c by one pointer. Forthcoming
255        implementation of support for (*MARK) will need an extra pointer on the
256        stack; I have reserved it now, so that the stack frame size does not
257        decrease.
258    
259    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
260        item in branch that calls a recursion is a subroutine call - as in the
261        second branch in the above example - was incorrectly given the compile-
262        time error "recursive call could loop indefinitely" because pcre_compile()
263        was not correctly checking the subroutine for matching a non-empty string.
264    
265    14. The checks for overrunning compiling workspace could trigger after an
266        overrun had occurred. This is a "should never occur" error, but it can be
267        triggered by pathological patterns such as hundreds of nested parentheses.
268        The checks now trigger 100 bytes before the end of the workspace.
269    
270    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
271    
272    
273    Version 8.01 19-Jan-2010
274    ------------------------
275    
276    1.  If a pattern contained a conditional subpattern with only one branch (in
277        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
278        computed the wrong minimum data length (which is of course zero for such
279        subpatterns). This could cause incorrect "no match" results.
280    
281    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
282        the pattern is reset in the first branch, pcre_compile() failed with
283        "internal error: code overflow at offset...". This happened only when
284        the reset was to the original external option setting. (An optimization
285        abstracts leading options settings into an external setting, which was the
286        cause of this.)
287    
288    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
289        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
290        assertion pattern did not match (meaning that the assertion was true), it
291        was incorrectly treated as false if the SKIP had been reached during the
292        matching. This also applied to assertions used as conditions.
293    
294    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
295        assertion subpattern, including such a pattern used as a condition,
296        unpredictable results occurred, instead of the error return
297        PCRE_ERROR_DFA_UITEM.
298    
299    5.  The C++ GlobalReplace function was not working like Perl for the special
300        situation when an empty string is matched. It now does the fancy magic
301        stuff that is necessary.
302    
303    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
304        removed. (These were left over from very, very early versions of PCRE.)
305    
306    7.  Some cosmetic changes to the code to make life easier when compiling it
307        as part of something else:
308    
309        (a) Change DEBUG to PCRE_DEBUG.
310    
311        (b) In pcre_compile(), rename the member of the "branch_chain" structure
312            called "current" as "current_branch", to prevent a collision with the
313            Linux macro when compiled as a kernel module.
314    
315        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
316            prevent a collision with the Linux macro when compiled as a kernel
317            module.
318    
319    8.  In pcre_compile() there are some checks for integer overflows that used to
320        cast potentially large values to (double). This has been changed to that
321        when building, a check for int64_t is made, and if it is found, it is used
322        instead, thus avoiding the use of floating point arithmetic. (There is no
323        other use of FP in PCRE.) If int64_t is not found, the fallback is to
324        double.
325    
326    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
327        2005 (difference between two addresses compared to an unsigned value).
328    
329    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
330        custom one, because of the following reported problem in Windows:
331    
332          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
333              under Win32.
334          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
335              therefore missing the function definition.
336          - The compiler thus generates a "C" signature for the test function.
337          - The linker fails to find the "C" function.
338          - PCRE fails to configure if asked to do so against libbz2.
339    
340    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
341        messages were output:
342    
343          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
344          rerunning libtoolize, to keep the correct libtool macros in-tree.
345          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
346    
347        I have done both of these things.
348    
349    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
350        most of the time, it *can* run out if it is given a pattern that contains a
351        runaway infinite recursion. I updated the discussion in the pcrestack man
352        page.
353    
354    13. Now that we have gone to the x.xx style of version numbers, the minor
355        version may start with zero. Using 08 or 09 is a bad idea because users
356        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
357        interpreted as invalid octal numbers. I've updated the previous comment in
358        configure.ac, and also added a check that gives an error if 08 or 09 are
359        used.
360    
361    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
362        causing partial matching to fail when the end of the subject matched \W
363        in a UTF-8 pattern where \W was quantified with a minimum of 3.
364    
365    15. There were some discrepancies between the declarations in pcre_internal.h
366        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
367        their definitions. The declarations used "const uschar *" and the
368        definitions used USPTR. Even though USPTR is normally defined as "const
369        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
370        reported that: "This difference in casting confuses some C++ compilers, for
371        example, SunCC recognizes above declarations as different functions and
372        generates broken code for hbpcre." I have changed the declarations to use
373        USPTR.
374    
375    16. GNU libtool is named differently on some systems. The autogen.sh script now
376        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
377        (FreeBSD).
378    
379    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
380        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
381        comment: "Figure out how to create a longlong from a string: strtoll and
382        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
383        instance, but it only takes 2 args instead of 3!"
384    
385    18. A subtle bug concerned with back references has been fixed by a change of
386        specification, with a corresponding code fix. A pattern such as
387        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
388        refers, was giving matches when it shouldn't. For example, xa=xaaa would
389        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
390        same bug. Such groups have to be quantified to be useful, or contained
391        inside another quantified group. (If there's no repetition, the reference
392        can never match.) The problem arises because, having left the group and
393        moved on to the rest of the pattern, a later failure that backtracks into
394        the group uses the captured value from the final iteration of the group
395        rather than the correct earlier one. I have fixed this in PCRE by forcing
396        any group that contains a reference to itself to be an atomic group; that
397        is, there cannot be any backtracking into it once it has completed. This is
398        similar to recursive and subroutine calls.
399    
400    
401    Version 8.00 19-Oct-09
402    ----------------------
403    
404    1.  The table for translating pcre_compile() error codes into POSIX error codes
405        was out-of-date, and there was no check on the pcre_compile() error code
406        being within the table. This could lead to an OK return being given in
407        error.
408    
409    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
410        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
411        in a Windows environment.
412    
413    3.  The pcregrep --count option prints the count for each file even when it is
414        zero, as does GNU grep. However, pcregrep was also printing all files when
415        --files-with-matches was added. Now, when both options are given, it prints
416        counts only for those files that have at least one match. (GNU grep just
417        prints the file name in this circumstance, but including the count seems
418        more useful - otherwise, why use --count?) Also ensured that the
419        combination -clh just lists non-zero counts, with no names.
420    
421    4.  The long form of the pcregrep -F option was incorrectly implemented as
422        --fixed_strings instead of --fixed-strings. This is an incompatible change,
423        but it seems right to fix it, and I didn't think it was worth preserving
424        the old behaviour.
425    
426    5.  The command line items --regex=pattern and --regexp=pattern were not
427        recognized by pcregrep, which required --regex pattern or --regexp pattern
428        (with a space rather than an '='). The man page documented the '=' forms,
429        which are compatible with GNU grep; these now work.
430    
431    6.  No libpcreposix.pc file was created for pkg-config; there was just
432        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
433    
434    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
435        when UCP support is not needed, by modifying the Python script that
436        generates it from Unicode data files. This should not matter if the module
437        is correctly used as a library, but I received one complaint about 50K of
438        unwanted data. My guess is that the person linked everything into his
439        program rather than using a library. Anyway, it does no harm.
440    
441    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
442        was a minimum greater than 1 for a wide character in a possessive
443        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
444        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
445        character. Chaos in the form of incorrect output or a compiling loop could
446        result.
447    
448    9.  The restrictions on what a pattern can contain when partial matching is
449        requested for pcre_exec() have been removed. All patterns can now be
450        partially matched by this function. In addition, if there are at least two
451        slots in the offset vector, the offset of the earliest inspected character
452        for the match and the offset of the end of the subject are set in them when
453        PCRE_ERROR_PARTIAL is returned.
454    
455    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
456        synonymous with PCRE_PARTIAL, for backwards compatibility, and
457        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
458        and may be more useful for multi-segment matching.
459    
460    11. Partial matching with pcre_exec() is now more intuitive. A partial match
461        used to be given if ever the end of the subject was reached; now it is
462        given only if matching could not proceed because another character was
463        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
464        string "Z", which now yields "no match" instead of "partial match". In the
465        case of pcre_dfa_exec(), "no match" is given if every matching path for the
466        final character ended with (*FAIL).
467    
468    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
469        if the pattern had a "must contain" character that was already found in the
470        earlier partial match, unless partial matching was again requested. For
471        example, with the pattern /dog.(body)?/, the "must contain" character is
472        "g". If the first part-match was for the string "dog", restarting with
473        "sbody" failed. This bug has been fixed.
474    
475    13. The string returned by pcre_dfa_exec() after a partial match has been
476        changed so that it starts at the first inspected character rather than the
477        first character of the match. This makes a difference only if the pattern
478        starts with a lookbehind assertion or \b or \B (\K is not supported by
479        pcre_dfa_exec()). It's an incompatible change, but it makes the two
480        matching functions compatible, and I think it's the right thing to do.
481    
482    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
483        so that the demonstration program is easily available in environments where
484        PCRE has not been installed from source.
485    
486    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
487        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
488        library.
489    
490    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
491        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
492        is not the first non-POSIX option to be added. Clearly some people find
493        these options useful.
494    
495    17. If a caller to the POSIX matching function regexec() passes a non-zero
496        value for nmatch with a NULL value for pmatch, the value of
497        nmatch is forced to zero.
498    
499    18. RunGrepTest did not have a test for the availability of the -u option of
500        the diff command, as RunTest does. It now checks in the same way as
501        RunTest, and also checks for the -b option.
502    
503    19. If an odd number of negated classes containing just a single character
504        interposed, within parentheses, between a forward reference to a named
505        subpattern and the definition of the subpattern, compilation crashed with
506        an internal error, complaining that it could not find the referenced
507        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
508        [The bug was that it was starting one character too far in when skipping
509        over the character class, thus treating the ] as data rather than
510        terminating the class. This meant it could skip too much.]
511    
512    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
513        /g option in pcretest when the pattern contains \K, which makes it possible
514        to have an empty string match not at the start, even when the pattern is
515        anchored. Updated pcretest and pcredemo to use this option.
516    
517    21. If the maximum number of capturing subpatterns in a recursion was greater
518        than the maximum at the outer level, the higher number was returned, but
519        with unset values at the outer level. The correct (outer level) value is
520        now given.
521    
522    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
523        PCRE did not set those parentheses (unlike Perl). I have now found a way to
524        make it do so. The string so far is captured, making this feature
525        compatible with Perl.
526    
527    23. The tests have been re-organized, adding tests 11 and 12, to make it
528        possible to check the Perl 5.10 features against Perl 5.10.
529    
530    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
531        pattern matches a fixed length string. PCRE did not allow this; now it
532        does. Neither allows recursion.
533    
534    25. I finally figured out how to implement a request to provide the minimum
535        length of subject string that was needed in order to match a given pattern.
536        (It was back references and recursion that I had previously got hung up
537        on.) This code has now been added to pcre_study(); it finds a lower bound
538        to the length of subject needed. It is not necessarily the greatest lower
539        bound, but using it to avoid searching strings that are too short does give
540        some useful speed-ups. The value is available to calling programs via
541        pcre_fullinfo().
542    
543    26. While implementing 25, I discovered to my embarrassment that pcretest had
544        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
545        study optimizations had never been tested with that matching function.
546        Oops. What is worse, even when it was passed study data, there was a bug in
547        pcre_dfa_exec() that meant it never actually used it. Double oops. There
548        were also very few tests of studied patterns with pcre_dfa_exec().
549    
550    27. If (?| is used to create subpatterns with duplicate numbers, they are now
551        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
552        on the other side of the coin, they are no longer allowed to have different
553        names, because these cannot be distinguished in PCRE, and this has caused
554        confusion. (This is a difference from Perl.)
555    
556    28. When duplicate subpattern names are present (necessarily with different
557        numbers, as required by 27 above), and a test is made by name in a
558        conditional pattern, either for a subpattern having been matched, or for
559        recursion in such a pattern, all the associated numbered subpatterns are
560        tested, and the overall condition is true if the condition is true for any
561        one of them. This is the way Perl works, and is also more like the way
562        testing by number works.
563    
564    
565    Version 7.9 11-Apr-09
566    ---------------------
567    
568    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
569        (pcretest), all targets were linked against these libraries. This included
570        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
571        libraries. This caused unwanted dependencies to be created. This problem
572        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
573        pcretest is linked with readline.
574    
575    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
576        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
577        moved outside it again, because FALSE and TRUE are already defined in AIX,
578        but BOOL is not.
579    
580    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
581        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
582    
583    4.  The pcregrep documentation said spaces were inserted as well as colons (or
584        hyphens) following file names and line numbers when outputting matching
585        lines. This is not true; no spaces are inserted. I have also clarified the
586        wording for the --colour (or --color) option.
587    
588    5.  In pcregrep, when --colour was used with -o, the list of matching strings
589        was not coloured; this is different to GNU grep, so I have changed it to be
590        the same.
591    
592    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
593        each matching line was coloured. Now it goes on to look for further matches
594        of any of the test patterns, which is the same behaviour as GNU grep.
595    
596    7.  A pattern that could match an empty string could cause pcregrep to loop; it
597        doesn't make sense to accept an empty string match in pcregrep, so I have
598        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
599        seems to be how GNU grep behaves.
600    
601    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
602        start or after a newline", because the conditional assertion was not being
603        correctly handled. The rule now is that both the assertion and what follows
604        in the first alternative must satisfy the test.
605    
606    9.  If auto-callout was enabled in a pattern with a conditional group whose
607        condition was an assertion, PCRE could crash during matching, both with
608        pcre_exec() and pcre_dfa_exec().
609    
610    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
611        used for matching.
612    
613    11. Unicode property support in character classes was not working for
614        characters (bytes) greater than 127 when not in UTF-8 mode.
615    
616    12. Added the -M command line option to pcretest.
617    
618    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
619    
620    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
621    
622    16. Added comments and documentation about mis-use of no_arg in the C++
623        wrapper.
624    
625    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
626        from Martin Jerabek that uses macro names for all relevant character and
627        string constants.
628    
629    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
630        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
631        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
632        these, but not everybody uses configure.
633    
634    19. A conditional group that had only one branch was not being correctly
635        recognized as an item that could match an empty string. This meant that an
636        enclosing group might also not be so recognized, causing infinite looping
637        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
638        with the subject "ab", where knowledge that the repeated group can match
639        nothing is needed in order to break the loop.
640    
641    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
642        exec(), but without supplying a callout function, matching went wrong.
643    
644    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
645        leak if the size of the offset vector was greater than 30. When the vector
646        is smaller, the saved offsets during recursion go onto a local stack
647        vector, but for larger vectors malloc() is used. It was failing to free
648        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
649        error, in fact).
650    
651    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
652        heapframe that is used only when UTF-8 support is enabled. This caused no
653        problem, but was untidy.
654    
655    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
656        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
657        included within another project.
658    
659    24. Steven Van Ingelgem's patches to add more options to the CMake support,
660        slightly modified by me:
661    
662          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
663              not building pcregrep.
664    
665          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
666              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
667    
668    25. Forward references, both numeric and by name, in patterns that made use of
669        duplicate group numbers, could behave incorrectly or give incorrect errors,
670        because when scanning forward to find the reference group, PCRE was not
671        taking into account the duplicate group numbers. A pattern such as
672        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
673    
674    26. Changed a few more instances of "const unsigned char *" to USPTR, making
675        the feature of a custom pointer more persuasive (as requested by a user).
676    
677    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
678        pcretest.c, inside #ifndefs, because it seems they are sometimes already
679        pre-defined.
680    
681    28. Added support for (*UTF8) at the start of a pattern.
682    
683    29. Arrange for flags added by the "release type" setting in CMake to be shown
684        in the configuration summary.
685    
686    
687    Version 7.8 05-Sep-08
688    ---------------------
689    
690    1.  Replaced UCP searching code with optimized version as implemented for Ad
691        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
692        stage table and inline lookup instead of a function, giving speed ups of 2
693        to 5 times on some simple patterns that I tested. Permission was given to
694        distribute the MultiStage2.py script that generates the tables (it's not in
695        the tarball, but is in the Subversion repository).
696    
697    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
698        scripts.
699    
700    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
701        a group with a zero qualifier. The result of the study could be incorrect,
702        or the function might crash, depending on the pattern.
703    
704    4.  Caseless matching was not working for non-ASCII characters in back
705        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
706        It now works when Unicode Property Support is available.
707    
708    5.  In pcretest, an escape such as \x{de} in the data was always generating
709        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
710        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
711        truncation.
712    
713    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
714    
715    7.  Added two (int) casts to pcregrep when printing the difference of two
716        pointers, in case they are 64-bit values.
717    
718    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
719        test 2 if it fails.
720    
721    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
722        and a #define of that name to empty if it is not externally set. This is to
723        allow users of MSVC to set it if necessary.
724    
725    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
726        the convenience functions in the pcre_get.c source file.
727    
728    11. An option change at the start of a pattern that had top-level alternatives
729        could cause overwriting and/or a crash. This command provoked a crash in
730        some environments:
731    
732          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
733    
734        This potential security problem was recorded as CVE-2008-2371.
735    
736    12. For a pattern where the match had to start at the beginning or immediately
737        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
738        pcre_dfa_exec() could read past the end of the passed subject if there was
739        no match. To help with detecting such bugs (e.g. with valgrind), I modified
740        pcretest so that it places the subject at the end of its malloc-ed buffer.
741    
742    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
743        exec() might read past the end of the data buffer in UTF-8 mode.
744    
745    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
746        the data contained the byte 0x85 as part of a UTF-8 character within its
747        first line. This applied both to normal and DFA matching.
748    
749    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
750        /^[^d]*?$/8 failed to match "abc".
751    
752    16. Added a missing copyright notice to pcrecpp_internal.h.
753    
754    17. Make it more clear in the documentation that values returned from
755        pcre_exec() in ovector are byte offsets, not character counts.
756    
757    18. Tidied a few places to stop certain compilers from issuing warnings.
758    
759    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
760        supplied by Stefan Weber. I made a further small update for 7.8 because
761        there is a change of source arrangements: the pcre_searchfuncs.c module is
762        replaced by pcre_ucd.c.
763    
764    
765    Version 7.7 07-May-08
766    ---------------------
767    
768    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
769        a string to a long long, pretend we don't even have a long long." This is
770        done by checking for the strtoq, strtoll, and _strtoi64 functions.
771    
772    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
773        pre-7.6 versions, which defined a global no_arg variable instead of putting
774        it in the RE class. (See also #8 below.)
775    
776    3.  Remove a line of dead code, identified by coverity and reported by Nuno
777        Lopes.
778    
779    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
780    
781        (1) The include/exclude patterns were being applied to the whole pathnames
782            of files, instead of just to the final components.
783    
784        (2) If there was more than one level of directory, the subdirectories were
785            skipped unless they satisfied the include/exclude conditions. This is
786            inconsistent with GNU grep (and could even be seen as contrary to the
787            pcregrep specification - which I improved to make it absolutely clear).
788            The action now is always to scan all levels of directory, and just
789            apply the include/exclude patterns to regular files.
790    
791    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
792        --exclude_dir in the tests to avoid scanning .svn directories.
793    
794    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
795        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
796        doesn't support NULs in patterns.
797    
798    7.  Added some missing "const"s to declarations of static tables in
799        pcre_compile.c and pcre_dfa_exec.c.
800    
801    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
802        caused by fix #2  above. (Subsequently also a second patch to fix the
803        first patch. And a third patch - this was a messy problem.)
804    
805    9.  Applied Craig's patch to remove the use of push_back().
806    
807    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
808        matching function regexec().
809    
810    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
811        which, however, unlike Perl's \g{...}, are subroutine calls, not back
812        references. PCRE supports relative numbers with this syntax (I don't think
813        Oniguruma does).
814    
815    12. Previously, a group with a zero repeat such as (...){0} was completely
816        omitted from the compiled regex. However, this means that if the group
817        was called as a subroutine from elsewhere in the pattern, things went wrong
818        (an internal error was given). Such groups are now left in the compiled
819        pattern, with a new opcode that causes them to be skipped at execution
820        time.
821    
822    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
823        to the way PCRE behaves:
824    
825        (a) A lone ] character is dis-allowed (Perl treats it as data).
826    
827        (b) A back reference to an unmatched subpattern matches an empty string
828            (Perl fails the current match path).
829    
830        (c) A data ] in a character class must be notated as \] because if the
831            first data character in a class is ], it defines an empty class. (In
832            Perl it is not possible to have an empty class.) The empty class []
833            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
834            The negative empty class [^] matches any one character, independently
835            of the DOTALL setting.
836    
837    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
838        non-existent subpattern following a character class starting with ']' and
839        containing () gave an internal compiling error instead of "reference to
840        non-existent subpattern". Fortunately, when the pattern did exist, the
841        compiled code was correct. (When scanning forwards to check for the
842        existencd of the subpattern, it was treating the data ']' as terminating
843        the class, so got the count wrong. When actually compiling, the reference
844        was subsequently set up correctly.)
845    
846    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
847        it was being rejected as not supported by pcre_dfa_exec(), even though
848        other assertions are supported. I have made pcre_dfa_exec() support
849        (*FAIL).
850    
851    16. The implementation of 13c above involved the invention of a new opcode,
852        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
853        cannot be changed at match time, I realized I could make a small
854        improvement to matching performance by compiling OP_ALLANY instead of
855        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
856        on the OP_ANY path.
857    
858    17. Compiling pcretest on Windows with readline support failed without the
859        following two fixes: (1) Make the unistd.h include conditional on
860        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
861    
862    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
863        ncurses library to be included for pcretest when ReadLine support is
864        requested, but also to allow for it to be overridden. This patch came from
865        Daniel Bergström.
866    
867    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
868        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
869        any errors with the current Unicode tables. Thanks to Peter Kankowski for
870        spotting this.
871    
872    
873    Version 7.6 28-Jan-08
874    ---------------------
875    
876    1.  A character class containing a very large number of characters with
877        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
878        overflow.
879    
880    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
881        HAVE_LONG_LONG is not defined.
882    
883    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
884        bring them up to date and include new features. This patch includes:
885    
886        - Fixed PH's badly added libz and libbz2 support.
887        - Fixed a problem with static linking.
888        - Added pcredemo. [But later removed - see 7 below.]
889        - Fixed dftables problem and added an option.
890        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
891            HAVE_LONG_LONG.
892        - Added readline support for pcretest.
893        - Added an listing of the option settings after cmake has run.
894    
895    4.  A user submitted a patch to Makefile that makes it easy to create
896        "pcre.dll" under mingw when using Configure/Make. I added stuff to
897        Makefile.am that cause it to include this special target, without
898        affecting anything else. Note that the same mingw target plus all
899        the other distribution libraries and programs are now supported
900        when configuring with CMake (see 6 below) instead of with
901        Configure/Make.
902    
903    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
904        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
905        exported in the Windows port". It has not yet been confirmed that the patch
906        solves the problem, but it does no harm.
907    
908    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
909        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
910        with CMake, and also correct the comment about stack recursion.
911    
912    7.  Remove the automatic building of pcredemo from the ./configure system and
913        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
914        of a program that users should build themselves after PCRE is installed, so
915        building it automatically is not really right. What is more, it gave
916        trouble in some build environments.
917    
918    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
919    
920    
921    Version 7.5 10-Jan-08
922    ---------------------
923    
924    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
925        values in parens when parsing an RE using the C++ wrapper."
926    
927    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
928        Characters greater than 255 were excluded from the class instead of being
929        included.
930    
931    3.  The same bug as (2) above applied to negated POSIX classes such as
932        [:^space:].
933    
934    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
935        defined or documented. It seems to have been a typo for PCRE_STATIC, so
936        I have changed it.
937    
938    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
939        first named subpattern) and a construct such as (?&a) would reference the
940        first named subpattern whose name started with "a" (in other words, the
941        length check was missing). Both these problems are fixed. "Subpattern name
942        expected" is now given for (?&) (a zero-length name), and this patch also
943        makes it give the same error for \k'' (previously it complained that that
944        was a reference to a non-existent subpattern).
945    
946    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
947        this is right because (?- can be followed by option settings as well as by
948        digits. I have, however, made the messages clearer.
949    
950    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
951        than the number used in the conditional) now cause a compile-time error.
952        This is actually not compatible with Perl, which accepts such patterns, but
953        treats the conditional as always being FALSE (as PCRE used to), but it
954        seems to me that giving a diagnostic is better.
955    
956    8.  Change "alphameric" to the more common word "alphanumeric" in comments
957        and messages.
958    
959    9.  Fix two occurrences of "backslash" in comments that should have been
960        "backspace".
961    
962    10. Remove two redundant lines of code that can never be obeyed (their function
963        was moved elsewhere).
964    
965    11. The program that makes PCRE's Unicode character property table had a bug
966        which caused it to generate incorrect table entries for sequences of
967        characters that have the same character type, but are in different scripts.
968        It amalgamated them into a single range, with the script of the first of
969        them. In other words, some characters were in the wrong script. There were
970        thirteen such cases, affecting characters in the following ranges:
971    
972          U+002b0 - U+002c1
973          U+0060c - U+0060d
974          U+0061e - U+00612
975          U+0064b - U+0065e
976          U+0074d - U+0076d
977          U+01800 - U+01805
978          U+01d00 - U+01d77
979          U+01d9b - U+01dbf
980          U+0200b - U+0200f
981          U+030fc - U+030fe
982          U+03260 - U+0327f
983          U+0fb46 - U+0fbb1
984          U+10450 - U+1049d
985    
986    12. The -o option (show only the matching part of a line) for pcregrep was not
987        compatible with GNU grep in that, if there was more than one match in a
988        line, it showed only the first of them. It now behaves in the same way as
989        GNU grep.
990    
991    13. If the -o and -v options were combined for pcregrep, it printed a blank
992        line for every non-matching line. GNU grep prints nothing, and pcregrep now
993        does the same. The return code can be used to tell if there were any
994        non-matching lines.
995    
996    14. Added --file-offsets and --line-offsets to pcregrep.
997    
998    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
999        infinitely looping recursion. The bug was that positive lookaheads were not
1000        being skipped when checking for a possible empty match (negative lookaheads
1001        and both kinds of lookbehind were skipped).
1002    
1003    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1004        inclusion of <windows.h> to before rather than after the definition of
1005        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1006    
1007    17. Specifying a possessive quantifier with a specific limit for a Unicode
1008        character property caused pcre_compile() to compile bad code, which led at
1009        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1010        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1011        caused the error; without that there was no problem.
1012    
1013    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1014    
1015    19. Added --enable-pcretest-libreadline.
1016    
1017    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1018        RE::GlobalReplace(). As a result, the number of replacements returned was
1019        double what it should be. I removed one of the increments, but Craig sent a
1020        later patch that removed the other one (the right fix) and added unit tests
1021        that check the return values (which was not done before).
1022    
1023    21. Several CMake things:
1024    
1025        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1026            the names libpcre and libpcreposix, not just pcre and pcreposix.
1027    
1028        (2) The above change means that pcretest and pcregrep are now correctly
1029            linked with the newly-built libraries, not previously installed ones.
1030    
1031        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1032    
1033    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1034        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1035        UTF-8 newline character). The key issue is that the pattern starts .*;
1036        this means that the match must be either at the beginning, or after a
1037        newline. The bug was in the code for advancing after a failed match and
1038        checking that the new position followed a newline. It was not taking
1039        account of UTF-8 characters correctly.
1040    
1041    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1042        character classes. PCRE was not treating the sequence [:...:] as a
1043        character class unless the ... were all letters. Perl, however, seems to
1044        allow any characters between [: and :], though of course it rejects as
1045        unknown any "names" that contain non-letters, because all the known class
1046        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1047        for example, whereas PCRE did not - it did not recognize a POSIX character
1048        class. This seemed a bit dangerous, so the code has been changed to be
1049        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1050        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1051        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1052        Perl does, and where it didn't before.
1053    
1054    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1055        Windows environments %n is disabled by default.
1056    
1057    
1058    Version 7.4 21-Sep-07
1059    ---------------------
1060    
1061    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1062        means that a class such as [\s] counted as "explicit reference to CR or
1063        LF". That isn't really right - the whole point of the change was to try to
1064        help when there was an actual mention of one of the two characters. So now
1065        the change happens only if \r or \n (or a literal CR or LF) character is
1066        encountered.
1067    
1068    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1069        of both had grown to the point where there were only 3 bits left.
1070        Fortunately, there was spare space in the data structure, and so I have
1071        moved the internal flags into a new 16-bit field to free up more option
1072        bits.
1073    
1074    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1075        but did not set the internal JCHANGED flag - either of these is enough to
1076        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1077        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1078        start sets both bits.
1079    
1080    4.  Added options (at build time, compile time, exec time) to change \R from
1081        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1082    
1083    5.  doc/pcresyntax.html was missing from the distribution.
1084    
1085    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1086        compatibility, even though it is no longer used.
1087    
1088    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1089        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1090        windows.h file is present (where different names are used). [This was
1091        reversed later after testing - see 16 below.]
1092    
1093    8.  Changed all #include <config.h> to #include "config.h". There were also
1094        some further <pcre.h> cases that I changed to "pcre.h".
1095    
1096    9.  When pcregrep was used with the --colour option, it missed the line ending
1097        sequence off the lines that it output.
1098    
1099    10. It was pointed out to me that arrays of string pointers cause lots of
1100        relocations when a shared library is dynamically loaded. A technique of
1101        using a single long string with a table of offsets can drastically reduce
1102        these. I have refactored PCRE in four places to do this. The result is
1103        dramatic:
1104    
1105          Originally:                          290
1106          After changing UCP table:            187
1107          After changing error message table:   43
1108          After changing table of "verbs"       36
1109          After changing table of Posix names   22
1110    
1111        Thanks to the folks working on Gregex for glib for this insight.
1112    
1113    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1114        unicode-properties was also set.
1115    
1116    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1117    
1118    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1119        checked only for CRLF.
1120    
1121    14. Added casts to pcretest.c to avoid compiler warnings.
1122    
1123    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1124    
1125    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1126        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1127        entirely. This removes changes made in 7 above.
1128    
1129    17. The CMake files have been updated, and there is now more information about
1130        building with CMake in the NON-UNIX-USE document.
1131    
1132    
1133    Version 7.3 28-Aug-07
1134    ---------------------
1135    
1136     1. In the rejigging of the build system that eventually resulted in 7.1, the
1137        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1138        brackets there is not right, since it causes compilers to look for an
1139        installed pcre.h, not the version that is in the source that is being
1140        compiled (which of course may be different). I have changed it back to:
1141    
1142          #include "pcre.h"
1143    
1144        I have a vague recollection that the change was concerned with compiling in
1145        different directories, but in the new build system, that is taken care of
1146        by the VPATH setting the Makefile.
1147    
1148     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1149        when the subject happened to end in the byte 0x85 (e.g. if the last
1150        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1151        characters but of course it shouldn't be taken as a newline when it is part
1152        of another character. The bug was that, for an unlimited repeat of . in
1153        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1154        characters when looking for a newline.
1155    
1156     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1157    
1158     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1159        in debug output.
1160    
1161     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1162        long printing in the pcrecpp unittest when running under MinGW.
1163    
1164     6. ESC_K was left out of the EBCDIC table.
1165    
1166     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1167        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1168        limit also applies to "virtual nesting" when a pattern is recursive, and in
1169        this case 1000 isn't so big. I have been able to remove this limit at the
1170        expense of backing off one optimization in certain circumstances. Normally,
1171        when pcre_exec() would call its internal match() function recursively and
1172        immediately return the result unconditionally, it uses a "tail recursion"
1173        feature to save stack. However, when a subpattern that can match an empty
1174        string has an unlimited repetition quantifier, it no longer makes this
1175        optimization. That gives it a stack frame in which to save the data for
1176        checking that an empty string has been matched. Previously this was taken
1177        from the 1000-entry workspace that had been reserved. So now there is no
1178        explicit limit, but more stack is used.
1179    
1180     8. Applied Daniel's patches to solve problems with the import/export magic
1181        syntax that is required for Windows, and which was going wrong for the
1182        pcreposix and pcrecpp parts of the library. These were overlooked when this
1183        problem was solved for the main library.
1184    
1185     9. There were some crude static tests to avoid integer overflow when computing
1186        the size of patterns that contain repeated groups with explicit upper
1187        limits. As the maximum quantifier is 65535, the maximum group length was
1188        set at 30,000 so that the product of these two numbers did not overflow a
1189        32-bit integer. However, it turns out that people want to use groups that
1190        are longer than 30,000 bytes (though not repeat them that many times).
1191        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1192        made it possible to implement the integer overflow checks in a much more
1193        dynamic way, which I have now done. The artificial limitation on group
1194        length has been removed - we now have only the limit on the total length of
1195        the compiled pattern, which depends on the LINK_SIZE setting.
1196    
1197    10. Fixed a bug in the documentation for get/copy named substring when
1198        duplicate names are permitted. If none of the named substrings are set, the
1199        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1200        empty string.
1201    
1202    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1203        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1204        because the ] is interpreted as the first data character and the
1205        terminating ] is not found. PCRE has been made compatible with Perl in this
1206        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1207        cause memory overwriting.
1208    
1209    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1210        string has been matched (to stop an infinite loop). It was not recognizing
1211        a conditional subpattern that could match an empty string if that
1212        subpattern was within another subpattern. For example, it looped when
1213        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1214        condition was not nested. This bug has been fixed.
1215    
1216    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1217        past the start of the subject in the presence of bytes with the top bit
1218        set, for example "\x8aBCD".
1219    
1220    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1221        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1222    
1223    14. Optimized (?!) to (*FAIL).
1224    
1225    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1226        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1227        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1228        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1229        does: it's just the validity check that is more restrictive.
1230    
1231    16. Inserted checks for integer overflows during escape sequence (backslash)
1232        processing, and also fixed erroneous offset values for syntax errors during
1233        backslash processing.
1234    
1235    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1236        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1237    
1238    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1239        caused an overrun.
1240    
1241    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1242        something other than just ASCII characters) inside a group that had an
1243        unlimited repeat caused a loop at compile time (while checking to see
1244        whether the group could match an empty string).
1245    
1246    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1247        [\P{Any}] did so. (Error in the code for printing property names.)
1248    
1249    21. An orphan \E inside a character class could cause a crash.
1250    
1251    22. A repeated capturing bracket such as (A)? could cause a wild memory
1252        reference during compilation.
1253    
1254    23. There are several functions in pcre_compile() that scan along a compiled
1255        expression for various reasons (e.g. to see if it's fixed length for look
1256        behind). There were bugs in these functions when a repeated \p or \P was
1257        present in the pattern. These operators have additional parameters compared
1258        with \d, etc, and these were not being taken into account when moving along
1259        the compiled data. Specifically:
1260    
1261        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1262            length.
1263    
1264        (b) An item such as \pL+ within a repeated group could cause crashes or
1265            loops.
1266    
1267        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1268            "reference to non-existent subpattern" error.
1269    
1270        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1271    
1272    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1273        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1274    
1275    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1276    
1277    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1278        character were causing crashes (broken optimization).
1279    
1280    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1281        \p or \P) caused a compile-time loop.
1282    
1283    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1284        break. For example, the unstudied pattern [\r\n]A does not match the string
1285        "\r\nA" because change 7.0/46 below moves the current point on by two
1286        characters after failing to match at the start. However, the pattern \nA
1287        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1288        the same is true. There doesn't seem any very clean way out of this, but
1289        what I have chosen to do makes the common cases work: PCRE now takes note
1290        of whether there can be an explicit match for \r or \n anywhere in the
1291        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1292        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1293        pattern has explicit CR or LF references.
1294    
1295    29. Added (*CR) etc for changing newline setting at start of pattern.
1296    
1297    
1298    Version 7.2 19-Jun-07
1299    ---------------------
1300    
1301     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1302        which is apparently normally available under Windows.
1303    
1304     2. Re-jig the pcregrep tests with different newline settings in an attempt
1305        to make them independent of the local environment's newline setting.
1306    
1307     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1308    
1309     4. Some of the "internals" tests were previously cut out when the link size
1310        was not 2, because the output contained actual offsets. The recent new
1311        "Z" feature of pcretest means that these can be cut out, making the tests
1312        usable with all link sizes.
1313    
1314     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1315        stack recursion. This gives a massive performance boost under BSD, but just
1316        a small improvement under Linux. However, it saves one field in the frame
1317        in all cases.
1318    
1319     6. Added more features from the forthcoming Perl 5.10:
1320    
1321        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1322            recursion call. It refers to the nth most recently opened parentheses.
1323    
1324        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1325            to be opened parentheses.
1326    
1327        (c) Conditions that refer to capturing parentheses can be specified
1328            relatively, for example, (?(-2)... or (?(+3)...
1329    
1330        (d) \K resets the start of the current match so that everything before
1331            is not part of it.
1332    
1333        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1334    
1335        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1336            reference syntax.
1337    
1338        (g) (?| introduces a group in which the numbering of parentheses in each
1339            alternative starts with the same number.
1340    
1341        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1342    
1343     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1344        PCRE_INFO_JCHANGED.
1345    
1346     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1347        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1348        for detecting groups that can match an empty string.
1349    
1350     9. A pattern with a very large number of alternatives (more than several
1351        hundred) was running out of internal workspace during the pre-compile
1352        phase, where pcre_compile() figures out how much memory will be needed. A
1353        bit of new cunning has reduced the workspace needed for groups with
1354        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1355        workspace instead of running out of the 4096 that are available.
1356    
1357    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1358    
1359    11. Applied patch from Google to remove an optimization that didn't quite work.
1360        The report of the bug said:
1361    
1362          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1363          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1364          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1365    
1366    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1367        it matched the wrong number of bytes.
1368    
1369    
1370    Version 7.1 24-Apr-07
1371    ---------------------
1372    
1373     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1374        that is more "standard", making use of automake and other Autotools. There
1375        is some re-arrangement of the files and adjustment of comments consequent
1376        on this.
1377    
1378     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1379        for recursive directory scanning broke on some systems because the files
1380        are not scanned in any specific order and on different systems the order
1381        was different. A call to "sort" has been inserted into RunGrepTest for the
1382        approprate test as a short-term fix. In the longer term there may be an
1383        alternative.
1384    
1385     3. I had an email from Eric Raymond about problems translating some of PCRE's
1386        man pages to HTML (despite the fact that I distribute HTML pages, some
1387        people do their own conversions for various reasons). The problems
1388        concerned the use of low-level troff macros .br and .in. I have therefore
1389        removed all such uses from the man pages (some were redundant, some could
1390        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1391        HTML has been updated to handle .nf/.fi and to complain if it encounters
1392        .br or .in.
1393    
1394     4. Updated comments in configure.ac that get placed in config.h.in and also
1395        arranged for config.h to be included in the distribution, with the name
1396        config.h.generic, for the benefit of those who have to compile without
1397        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1398    
1399     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1400        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1401        makevp.bat for the current PCRE, using the additional files
1402        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1403    
1404     6. A Windows user reported a minor discrepancy with test 2, which turned out
1405        to be caused by a trailing space on an input line that had got lost in his
1406        copy. The trailing space was an accident, so I've just removed it.
1407    
1408     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1409        that is needed.
1410    
1411     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1412        as "const" (a) because they are and (b) because it helps the PHP
1413        maintainers who have recently made a script to detect big data structures
1414        in the php code that should be moved to the .rodata section. I remembered
1415        to update Builducptable as well, so it won't revert if ucptable.h is ever
1416        re-created.
1417    
1418     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1419        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1420        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1421        support is not required. This saves 1.5-2K of code, which is important in
1422        some applications.
1423    
1424        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1425        so as not to refer to the tables, even though these functions will never be
1426        called when UTF-8 support is disabled. Otherwise there are problems with a
1427        shared library.
1428    
1429    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1430    
1431        (a) It was defining its arguments as char * instead of void *.
1432    
1433        (b) It was assuming that all moves were upwards in memory; this was true
1434            a long time ago when I wrote it, but is no longer the case.
1435    
1436        The emulated memove() is provided for those environments that have neither
1437        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1438        is clearly not the case, as these two bugs were recently reported.
1439    
1440    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1441        and Detrail to create the HTML documentation, the .txt form of the man
1442        pages, and it removes trailing spaces from listed files. It also creates
1443        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1444        case, it wraps all the #defines with #ifndefs. This script should be run
1445        before "make dist".
1446    
1447    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1448        with Unicode property support.
1449    
1450        (a) For a maximizing quantifier, if the two different cases of the
1451            character were of different lengths in their UTF-8 codings (there are
1452            some cases like this - I found 11), and the matching function had to
1453            back up over a mixture of the two cases, it incorrectly assumed they
1454            were both the same length.
1455    
1456        (b) When PCRE was configured to use the heap rather than the stack for
1457            recursion during matching, it was not correctly preserving the data for
1458            the other case of a UTF-8 character when checking ahead for a match
1459            while processing a minimizing repeat. If the check also involved
1460            matching a wide character, but failed, corruption could cause an
1461            erroneous result when trying to check for a repeat of the original
1462            character.
1463    
1464    13. Some tidying changes to the testing mechanism:
1465    
1466        (a) The RunTest script now detects the internal link size and whether there
1467            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1468            values substituted by "configure". (The RunGrepTest script already did
1469            this for UTF-8.) The configure.ac script no longer substitutes the
1470            relevant variables.
1471    
1472        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1473            with length and offset values. This means that the output is different
1474            for different internal link sizes. Test 2 is skipped for link sizes
1475            other than 2 because of this, bypassing the problem. Unfortunately,
1476            there was also a test in test 3 (the locale tests) that used /B and
1477            failed for link sizes other than 2. Rather than cut the whole test out,
1478            I have added a new /Z option to pcretest that replaces the length and
1479            offset values with spaces. This is now used to make test 3 independent
1480            of link size. (Test 2 will be tidied up later.)
1481    
1482    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1483        segmentation fault instead of returning the appropriate error message.
1484    
1485    15. In multiline mode when the newline sequence was set to "any", the pattern
1486        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1487        This doesn't seem right; it now treats the CRLF combination as the line
1488        ending, and so does not match in that case. It's only a pattern such as ^$
1489        that would hit this one: something like ^ABC$ would have failed after \r
1490        and then tried again after \r\n.
1491    
1492    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1493        in an attempt to make files that differ only in their line terminators
1494        compare equal. This works on Linux.
1495    
1496    17. Under certain error circumstances pcregrep might try to free random memory
1497        as it exited. This is now fixed, thanks to valgrind.
1498    
1499    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1500        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1501        was because its rules for how to advance for /g after matching an empty
1502        string at the end of a line did not allow for this case. They now check for
1503        it specially.
1504    
1505    20. pcretest is supposed to handle patterns and data of any length, by
1506        extending its buffers when necessary. It was getting this wrong when the
1507        buffer for a data line had to be extended.
1508    
1509    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1510        CRLF as a newline sequence.
1511    
1512    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1513        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1514        I have nevertheless tidied it up.
1515    
1516    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1517    
1518    24. Added a man page for pcre-config.
1519    
1520    
1521  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1522  ---------------------  ---------------------
1523    

Legend:
Removed from v.96  
changed lines
  Added in v.573

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12