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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 01-May-07  Version 8.10 03-Jun-2010
5    ------------------------
6    
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
9    
10    2.  (*ACCEPT) was not working when inside an atomic group.
11    
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
15    
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
19    
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
22    
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
28    
29    7.  Minor change to pcretest.c to avoid a compiler warning.
30    
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
39    
40    10. Added --line-buffered to pcregrep.
41    
42    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43        studied, and the match started with a letter with a code point greater than
44        127 whose first byte was different to the first byte of the other case of
45        the letter, the other case of this starting letter was not recognized
46        (#976).
47    
48    12. If a pattern that was studied started with a repeated Unicode property
49        test, for example, \p{Nd}+, there was the theoretical possibility of
50        setting up an incorrect bitmap of starting bytes, but fortunately it could
51        not have actually happened in practice until change 8 above was made (it
52        added property types that matched character-matching opcodes).
53    
54    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
55        possible starting bytes for non-anchored patterns.
56    
57    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
58        \R, and also a number of cases that involve Unicode properties, both
59        explicit and implicit when PCRE_UCP is set.
60    
61    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
62        input, it could crash or give wrong results if characters with values
63        greater than 0xc0 were present in the subject string. (Detail: it assumed
64        UTF-8 input when processing these items.)
65    
66    16. Added a lot of (int) casts to avoid compiler warnings in systems where
67        size_t is 64-bit (#991).
68    
69    17. Added a check for running out of memory when PCRE is compiled with
70        --disable-stack-for-recursion (#990).
71    
72    18. If the last data line in a file for pcretest does not have a newline on
73        the end, a newline was missing in the output.
74    
75    19. The default pcre_chartables.c file recognizes only ASCII characters (values
76        less than 128) in its various bitmaps. However, there is a facility for
77        generating tables according to the current locale when PCRE is compiled. It
78        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
79        characters, are recognized by isspace() and therefore were getting set in
80        these tables, and indeed these tables seem to approximate to ISO 8859. This
81        caused a problem in UTF-8 mode when pcre_study() was used to create a list
82        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
83        which of course cannot start UTF-8 characters. I have changed the code so
84        that only real ASCII characters (less than 128) and the correct starting
85        bytes for UTF-8 encodings are set for characters greater than 127 when in
86        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
87        altogether.)
88    
89    20. Added the /T option to pcretest so as to be able to run tests with non-
90        standard character tables, thus making it possible to include the tests
91        used for 19 above in the standard set of tests.
92    
93    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
94        reference to a subpattern the other side of a comment that contains an
95        opening parenthesis caused either an internal compiling error, or a
96        reference to the wrong subpattern.
97    
98    
99    Version 8.02 19-Mar-2010
100    ------------------------
101    
102    1.  The Unicode data tables have been updated to Unicode 5.2.0.
103    
104    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
105        configured.
106    
107    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
108        original author of that file, following a query about its status.
109    
110    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
111        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
112    
113    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
114        quantifier applied to a forward-referencing subroutine call, could compile
115        incorrect code or give the error "internal error: previously-checked
116        referenced subpattern not found".
117    
118    6.  Both MS Visual Studio and Symbian OS have problems with initializing
119        variables to point to external functions. For these systems, therefore,
120        pcre_malloc etc. are now initialized to local functions that call the
121        relevant global functions.
122    
123    7.  There were two entries missing in the vectors called coptable and poptable
124        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
125        I've fixed the data, and added a kludgy way of testing at compile time that
126        the lengths are correct (equal to the number of opcodes).
127    
128    8.  Following on from 7, I added a similar kludge to check the length of the
129        eint vector in pcreposix.c.
130    
131    9.  Error texts for pcre_compile() are held as one long string to avoid too
132        much relocation at load time. To find a text, the string is searched,
133        counting zeros. There was no check for running off the end of the string,
134        which could happen if a new error number was added without updating the
135        string.
136    
137    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
138    
139    11. \K was not working if it appeared in an atomic group or in a group that
140        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
141        \K is "not well defined" if used in an assertion. PCRE now accepts it if
142        the assertion is positive, but not if it is negative.
143    
144    12. Change 11 fortuitously reduced the size of the stack frame used in the
145        "match()" function of pcre_exec.c by one pointer. Forthcoming
146        implementation of support for (*MARK) will need an extra pointer on the
147        stack; I have reserved it now, so that the stack frame size does not
148        decrease.
149    
150    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
151        item in branch that calls a recursion is a subroutine call - as in the
152        second branch in the above example - was incorrectly given the compile-
153        time error "recursive call could loop indefinitely" because pcre_compile()
154        was not correctly checking the subroutine for matching a non-empty string.
155    
156    14. The checks for overrunning compiling workspace could trigger after an
157        overrun had occurred. This is a "should never occur" error, but it can be
158        triggered by pathological patterns such as hundreds of nested parentheses.
159        The checks now trigger 100 bytes before the end of the workspace.
160    
161    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
162    
163    
164    Version 8.01 19-Jan-2010
165    ------------------------
166    
167    1.  If a pattern contained a conditional subpattern with only one branch (in
168        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
169        computed the wrong minimum data length (which is of course zero for such
170        subpatterns). This could cause incorrect "no match" results.
171    
172    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
173        the pattern is reset in the first branch, pcre_compile() failed with
174        "internal error: code overflow at offset...". This happened only when
175        the reset was to the original external option setting. (An optimization
176        abstracts leading options settings into an external setting, which was the
177        cause of this.)
178    
179    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
180        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
181        assertion pattern did not match (meaning that the assertion was true), it
182        was incorrectly treated as false if the SKIP had been reached during the
183        matching. This also applied to assertions used as conditions.
184    
185    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
186        assertion subpattern, including such a pattern used as a condition,
187        unpredictable results occurred, instead of the error return
188        PCRE_ERROR_DFA_UITEM.
189    
190    5.  The C++ GlobalReplace function was not working like Perl for the special
191        situation when an empty string is matched. It now does the fancy magic
192        stuff that is necessary.
193    
194    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
195        removed. (These were left over from very, very early versions of PCRE.)
196    
197    7.  Some cosmetic changes to the code to make life easier when compiling it
198        as part of something else:
199    
200        (a) Change DEBUG to PCRE_DEBUG.
201    
202        (b) In pcre_compile(), rename the member of the "branch_chain" structure
203            called "current" as "current_branch", to prevent a collision with the
204            Linux macro when compiled as a kernel module.
205    
206        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
207            prevent a collision with the Linux macro when compiled as a kernel
208            module.
209    
210    8.  In pcre_compile() there are some checks for integer overflows that used to
211        cast potentially large values to (double). This has been changed to that
212        when building, a check for int64_t is made, and if it is found, it is used
213        instead, thus avoiding the use of floating point arithmetic. (There is no
214        other use of FP in PCRE.) If int64_t is not found, the fallback is to
215        double.
216    
217    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
218        2005 (difference between two addresses compared to an unsigned value).
219    
220    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
221        custom one, because of the following reported problem in Windows:
222    
223          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
224              under Win32.
225          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
226              therefore missing the function definition.
227          - The compiler thus generates a "C" signature for the test function.
228          - The linker fails to find the "C" function.
229          - PCRE fails to configure if asked to do so against libbz2.
230    
231    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
232        messages were output:
233    
234          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
235          rerunning libtoolize, to keep the correct libtool macros in-tree.
236          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
237    
238        I have done both of these things.
239    
240    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
241        most of the time, it *can* run out if it is given a pattern that contains a
242        runaway infinite recursion. I updated the discussion in the pcrestack man
243        page.
244    
245    13. Now that we have gone to the x.xx style of version numbers, the minor
246        version may start with zero. Using 08 or 09 is a bad idea because users
247        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
248        interpreted as invalid octal numbers. I've updated the previous comment in
249        configure.ac, and also added a check that gives an error if 08 or 09 are
250        used.
251    
252    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
253        causing partial matching to fail when the end of the subject matched \W
254        in a UTF-8 pattern where \W was quantified with a minimum of 3.
255    
256    15. There were some discrepancies between the declarations in pcre_internal.h
257        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
258        their definitions. The declarations used "const uschar *" and the
259        definitions used USPTR. Even though USPTR is normally defined as "const
260        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
261        reported that: "This difference in casting confuses some C++ compilers, for
262        example, SunCC recognizes above declarations as different functions and
263        generates broken code for hbpcre." I have changed the declarations to use
264        USPTR.
265    
266    16. GNU libtool is named differently on some systems. The autogen.sh script now
267        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
268        (FreeBSD).
269    
270    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
271        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
272        comment: "Figure out how to create a longlong from a string: strtoll and
273        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
274        instance, but it only takes 2 args instead of 3!"
275    
276    18. A subtle bug concerned with back references has been fixed by a change of
277        specification, with a corresponding code fix. A pattern such as
278        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
279        refers, was giving matches when it shouldn't. For example, xa=xaaa would
280        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
281        same bug. Such groups have to be quantified to be useful, or contained
282        inside another quantified group. (If there's no repetition, the reference
283        can never match.) The problem arises because, having left the group and
284        moved on to the rest of the pattern, a later failure that backtracks into
285        the group uses the captured value from the final iteration of the group
286        rather than the correct earlier one. I have fixed this in PCRE by forcing
287        any group that contains a reference to itself to be an atomic group; that
288        is, there cannot be any backtracking into it once it has completed. This is
289        similar to recursive and subroutine calls.
290    
291    
292    Version 8.00 19-Oct-09
293    ----------------------
294    
295    1.  The table for translating pcre_compile() error codes into POSIX error codes
296        was out-of-date, and there was no check on the pcre_compile() error code
297        being within the table. This could lead to an OK return being given in
298        error.
299    
300    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
301        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
302        in a Windows environment.
303    
304    3.  The pcregrep --count option prints the count for each file even when it is
305        zero, as does GNU grep. However, pcregrep was also printing all files when
306        --files-with-matches was added. Now, when both options are given, it prints
307        counts only for those files that have at least one match. (GNU grep just
308        prints the file name in this circumstance, but including the count seems
309        more useful - otherwise, why use --count?) Also ensured that the
310        combination -clh just lists non-zero counts, with no names.
311    
312    4.  The long form of the pcregrep -F option was incorrectly implemented as
313        --fixed_strings instead of --fixed-strings. This is an incompatible change,
314        but it seems right to fix it, and I didn't think it was worth preserving
315        the old behaviour.
316    
317    5.  The command line items --regex=pattern and --regexp=pattern were not
318        recognized by pcregrep, which required --regex pattern or --regexp pattern
319        (with a space rather than an '='). The man page documented the '=' forms,
320        which are compatible with GNU grep; these now work.
321    
322    6.  No libpcreposix.pc file was created for pkg-config; there was just
323        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
324    
325    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
326        when UCP support is not needed, by modifying the Python script that
327        generates it from Unicode data files. This should not matter if the module
328        is correctly used as a library, but I received one complaint about 50K of
329        unwanted data. My guess is that the person linked everything into his
330        program rather than using a library. Anyway, it does no harm.
331    
332    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
333        was a minimum greater than 1 for a wide character in a possessive
334        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
335        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
336        character. Chaos in the form of incorrect output or a compiling loop could
337        result.
338    
339    9.  The restrictions on what a pattern can contain when partial matching is
340        requested for pcre_exec() have been removed. All patterns can now be
341        partially matched by this function. In addition, if there are at least two
342        slots in the offset vector, the offset of the earliest inspected character
343        for the match and the offset of the end of the subject are set in them when
344        PCRE_ERROR_PARTIAL is returned.
345    
346    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
347        synonymous with PCRE_PARTIAL, for backwards compatibility, and
348        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
349        and may be more useful for multi-segment matching.
350    
351    11. Partial matching with pcre_exec() is now more intuitive. A partial match
352        used to be given if ever the end of the subject was reached; now it is
353        given only if matching could not proceed because another character was
354        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
355        string "Z", which now yields "no match" instead of "partial match". In the
356        case of pcre_dfa_exec(), "no match" is given if every matching path for the
357        final character ended with (*FAIL).
358    
359    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
360        if the pattern had a "must contain" character that was already found in the
361        earlier partial match, unless partial matching was again requested. For
362        example, with the pattern /dog.(body)?/, the "must contain" character is
363        "g". If the first part-match was for the string "dog", restarting with
364        "sbody" failed. This bug has been fixed.
365    
366    13. The string returned by pcre_dfa_exec() after a partial match has been
367        changed so that it starts at the first inspected character rather than the
368        first character of the match. This makes a difference only if the pattern
369        starts with a lookbehind assertion or \b or \B (\K is not supported by
370        pcre_dfa_exec()). It's an incompatible change, but it makes the two
371        matching functions compatible, and I think it's the right thing to do.
372    
373    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
374        so that the demonstration program is easily available in environments where
375        PCRE has not been installed from source.
376    
377    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
378        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
379        library.
380    
381    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
382        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
383        is not the first non-POSIX option to be added. Clearly some people find
384        these options useful.
385    
386    17. If a caller to the POSIX matching function regexec() passes a non-zero
387        value for nmatch with a NULL value for pmatch, the value of
388        nmatch is forced to zero.
389    
390    18. RunGrepTest did not have a test for the availability of the -u option of
391        the diff command, as RunTest does. It now checks in the same way as
392        RunTest, and also checks for the -b option.
393    
394    19. If an odd number of negated classes containing just a single character
395        interposed, within parentheses, between a forward reference to a named
396        subpattern and the definition of the subpattern, compilation crashed with
397        an internal error, complaining that it could not find the referenced
398        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
399        [The bug was that it was starting one character too far in when skipping
400        over the character class, thus treating the ] as data rather than
401        terminating the class. This meant it could skip too much.]
402    
403    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
404        /g option in pcretest when the pattern contains \K, which makes it possible
405        to have an empty string match not at the start, even when the pattern is
406        anchored. Updated pcretest and pcredemo to use this option.
407    
408    21. If the maximum number of capturing subpatterns in a recursion was greater
409        than the maximum at the outer level, the higher number was returned, but
410        with unset values at the outer level. The correct (outer level) value is
411        now given.
412    
413    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
414        PCRE did not set those parentheses (unlike Perl). I have now found a way to
415        make it do so. The string so far is captured, making this feature
416        compatible with Perl.
417    
418    23. The tests have been re-organized, adding tests 11 and 12, to make it
419        possible to check the Perl 5.10 features against Perl 5.10.
420    
421    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
422        pattern matches a fixed length string. PCRE did not allow this; now it
423        does. Neither allows recursion.
424    
425    25. I finally figured out how to implement a request to provide the minimum
426        length of subject string that was needed in order to match a given pattern.
427        (It was back references and recursion that I had previously got hung up
428        on.) This code has now been added to pcre_study(); it finds a lower bound
429        to the length of subject needed. It is not necessarily the greatest lower
430        bound, but using it to avoid searching strings that are too short does give
431        some useful speed-ups. The value is available to calling programs via
432        pcre_fullinfo().
433    
434    26. While implementing 25, I discovered to my embarrassment that pcretest had
435        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
436        study optimizations had never been tested with that matching function.
437        Oops. What is worse, even when it was passed study data, there was a bug in
438        pcre_dfa_exec() that meant it never actually used it. Double oops. There
439        were also very few tests of studied patterns with pcre_dfa_exec().
440    
441    27. If (?| is used to create subpatterns with duplicate numbers, they are now
442        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
443        on the other side of the coin, they are no longer allowed to have different
444        names, because these cannot be distinguished in PCRE, and this has caused
445        confusion. (This is a difference from Perl.)
446    
447    28. When duplicate subpattern names are present (necessarily with different
448        numbers, as required by 27 above), and a test is made by name in a
449        conditional pattern, either for a subpattern having been matched, or for
450        recursion in such a pattern, all the associated numbered subpatterns are
451        tested, and the overall condition is true if the condition is true for any
452        one of them. This is the way Perl works, and is also more like the way
453        testing by number works.
454    
455    
456    Version 7.9 11-Apr-09
457    ---------------------
458    
459    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
460        (pcretest), all targets were linked against these libraries. This included
461        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
462        libraries. This caused unwanted dependencies to be created. This problem
463        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
464        pcretest is linked with readline.
465    
466    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
467        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
468        moved outside it again, because FALSE and TRUE are already defined in AIX,
469        but BOOL is not.
470    
471    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
472        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
473    
474    4.  The pcregrep documentation said spaces were inserted as well as colons (or
475        hyphens) following file names and line numbers when outputting matching
476        lines. This is not true; no spaces are inserted. I have also clarified the
477        wording for the --colour (or --color) option.
478    
479    5.  In pcregrep, when --colour was used with -o, the list of matching strings
480        was not coloured; this is different to GNU grep, so I have changed it to be
481        the same.
482    
483    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
484        each matching line was coloured. Now it goes on to look for further matches
485        of any of the test patterns, which is the same behaviour as GNU grep.
486    
487    7.  A pattern that could match an empty string could cause pcregrep to loop; it
488        doesn't make sense to accept an empty string match in pcregrep, so I have
489        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
490        seems to be how GNU grep behaves.
491    
492    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
493        start or after a newline", because the conditional assertion was not being
494        correctly handled. The rule now is that both the assertion and what follows
495        in the first alternative must satisfy the test.
496    
497    9.  If auto-callout was enabled in a pattern with a conditional group whose
498        condition was an assertion, PCRE could crash during matching, both with
499        pcre_exec() and pcre_dfa_exec().
500    
501    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
502        used for matching.
503    
504    11. Unicode property support in character classes was not working for
505        characters (bytes) greater than 127 when not in UTF-8 mode.
506    
507    12. Added the -M command line option to pcretest.
508    
509    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
510    
511    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
512    
513    16. Added comments and documentation about mis-use of no_arg in the C++
514        wrapper.
515    
516    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
517        from Martin Jerabek that uses macro names for all relevant character and
518        string constants.
519    
520    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
521        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
522        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
523        these, but not everybody uses configure.
524    
525    19. A conditional group that had only one branch was not being correctly
526        recognized as an item that could match an empty string. This meant that an
527        enclosing group might also not be so recognized, causing infinite looping
528        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
529        with the subject "ab", where knowledge that the repeated group can match
530        nothing is needed in order to break the loop.
531    
532    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
533        exec(), but without supplying a callout function, matching went wrong.
534    
535    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
536        leak if the size of the offset vector was greater than 30. When the vector
537        is smaller, the saved offsets during recursion go onto a local stack
538        vector, but for larger vectors malloc() is used. It was failing to free
539        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
540        error, in fact).
541    
542    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
543        heapframe that is used only when UTF-8 support is enabled. This caused no
544        problem, but was untidy.
545    
546    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
547        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
548        included within another project.
549    
550    24. Steven Van Ingelgem's patches to add more options to the CMake support,
551        slightly modified by me:
552    
553          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
554              not building pcregrep.
555    
556          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
557              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
558    
559    25. Forward references, both numeric and by name, in patterns that made use of
560        duplicate group numbers, could behave incorrectly or give incorrect errors,
561        because when scanning forward to find the reference group, PCRE was not
562        taking into account the duplicate group numbers. A pattern such as
563        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
564    
565    26. Changed a few more instances of "const unsigned char *" to USPTR, making
566        the feature of a custom pointer more persuasive (as requested by a user).
567    
568    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
569        pcretest.c, inside #ifndefs, because it seems they are sometimes already
570        pre-defined.
571    
572    28. Added support for (*UTF8) at the start of a pattern.
573    
574    29. Arrange for flags added by the "release type" setting in CMake to be shown
575        in the configuration summary.
576    
577    
578    Version 7.8 05-Sep-08
579    ---------------------
580    
581    1.  Replaced UCP searching code with optimized version as implemented for Ad
582        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
583        stage table and inline lookup instead of a function, giving speed ups of 2
584        to 5 times on some simple patterns that I tested. Permission was given to
585        distribute the MultiStage2.py script that generates the tables (it's not in
586        the tarball, but is in the Subversion repository).
587    
588    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
589        scripts.
590    
591    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
592        a group with a zero qualifier. The result of the study could be incorrect,
593        or the function might crash, depending on the pattern.
594    
595    4.  Caseless matching was not working for non-ASCII characters in back
596        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
597        It now works when Unicode Property Support is available.
598    
599    5.  In pcretest, an escape such as \x{de} in the data was always generating
600        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
601        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
602        truncation.
603    
604    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
605    
606    7.  Added two (int) casts to pcregrep when printing the difference of two
607        pointers, in case they are 64-bit values.
608    
609    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
610        test 2 if it fails.
611    
612    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
613        and a #define of that name to empty if it is not externally set. This is to
614        allow users of MSVC to set it if necessary.
615    
616    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
617        the convenience functions in the pcre_get.c source file.
618    
619    11. An option change at the start of a pattern that had top-level alternatives
620        could cause overwriting and/or a crash. This command provoked a crash in
621        some environments:
622    
623          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
624    
625        This potential security problem was recorded as CVE-2008-2371.
626    
627    12. For a pattern where the match had to start at the beginning or immediately
628        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
629        pcre_dfa_exec() could read past the end of the passed subject if there was
630        no match. To help with detecting such bugs (e.g. with valgrind), I modified
631        pcretest so that it places the subject at the end of its malloc-ed buffer.
632    
633    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
634        exec() might read past the end of the data buffer in UTF-8 mode.
635    
636    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
637        the data contained the byte 0x85 as part of a UTF-8 character within its
638        first line. This applied both to normal and DFA matching.
639    
640    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
641        /^[^d]*?$/8 failed to match "abc".
642    
643    16. Added a missing copyright notice to pcrecpp_internal.h.
644    
645    17. Make it more clear in the documentation that values returned from
646        pcre_exec() in ovector are byte offsets, not character counts.
647    
648    18. Tidied a few places to stop certain compilers from issuing warnings.
649    
650    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
651        supplied by Stefan Weber. I made a further small update for 7.8 because
652        there is a change of source arrangements: the pcre_searchfuncs.c module is
653        replaced by pcre_ucd.c.
654    
655    
656    Version 7.7 07-May-08
657    ---------------------
658    
659    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
660        a string to a long long, pretend we don't even have a long long." This is
661        done by checking for the strtoq, strtoll, and _strtoi64 functions.
662    
663    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
664        pre-7.6 versions, which defined a global no_arg variable instead of putting
665        it in the RE class. (See also #8 below.)
666    
667    3.  Remove a line of dead code, identified by coverity and reported by Nuno
668        Lopes.
669    
670    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
671    
672        (1) The include/exclude patterns were being applied to the whole pathnames
673            of files, instead of just to the final components.
674    
675        (2) If there was more than one level of directory, the subdirectories were
676            skipped unless they satisfied the include/exclude conditions. This is
677            inconsistent with GNU grep (and could even be seen as contrary to the
678            pcregrep specification - which I improved to make it absolutely clear).
679            The action now is always to scan all levels of directory, and just
680            apply the include/exclude patterns to regular files.
681    
682    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
683        --exclude_dir in the tests to avoid scanning .svn directories.
684    
685    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
686        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
687        doesn't support NULs in patterns.
688    
689    7.  Added some missing "const"s to declarations of static tables in
690        pcre_compile.c and pcre_dfa_exec.c.
691    
692    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
693        caused by fix #2  above. (Subsequently also a second patch to fix the
694        first patch. And a third patch - this was a messy problem.)
695    
696    9.  Applied Craig's patch to remove the use of push_back().
697    
698    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
699        matching function regexec().
700    
701    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
702        which, however, unlike Perl's \g{...}, are subroutine calls, not back
703        references. PCRE supports relative numbers with this syntax (I don't think
704        Oniguruma does).
705    
706    12. Previously, a group with a zero repeat such as (...){0} was completely
707        omitted from the compiled regex. However, this means that if the group
708        was called as a subroutine from elsewhere in the pattern, things went wrong
709        (an internal error was given). Such groups are now left in the compiled
710        pattern, with a new opcode that causes them to be skipped at execution
711        time.
712    
713    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
714        to the way PCRE behaves:
715    
716        (a) A lone ] character is dis-allowed (Perl treats it as data).
717    
718        (b) A back reference to an unmatched subpattern matches an empty string
719            (Perl fails the current match path).
720    
721        (c) A data ] in a character class must be notated as \] because if the
722            first data character in a class is ], it defines an empty class. (In
723            Perl it is not possible to have an empty class.) The empty class []
724            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
725            The negative empty class [^] matches any one character, independently
726            of the DOTALL setting.
727    
728    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
729        non-existent subpattern following a character class starting with ']' and
730        containing () gave an internal compiling error instead of "reference to
731        non-existent subpattern". Fortunately, when the pattern did exist, the
732        compiled code was correct. (When scanning forwards to check for the
733        existencd of the subpattern, it was treating the data ']' as terminating
734        the class, so got the count wrong. When actually compiling, the reference
735        was subsequently set up correctly.)
736    
737    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
738        it was being rejected as not supported by pcre_dfa_exec(), even though
739        other assertions are supported. I have made pcre_dfa_exec() support
740        (*FAIL).
741    
742    16. The implementation of 13c above involved the invention of a new opcode,
743        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
744        cannot be changed at match time, I realized I could make a small
745        improvement to matching performance by compiling OP_ALLANY instead of
746        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
747        on the OP_ANY path.
748    
749    17. Compiling pcretest on Windows with readline support failed without the
750        following two fixes: (1) Make the unistd.h include conditional on
751        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
752    
753    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
754        ncurses library to be included for pcretest when ReadLine support is
755        requested, but also to allow for it to be overridden. This patch came from
756        Daniel Bergström.
757    
758    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
759        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
760        any errors with the current Unicode tables. Thanks to Peter Kankowski for
761        spotting this.
762    
763    
764    Version 7.6 28-Jan-08
765    ---------------------
766    
767    1.  A character class containing a very large number of characters with
768        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
769        overflow.
770    
771    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
772        HAVE_LONG_LONG is not defined.
773    
774    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
775        bring them up to date and include new features. This patch includes:
776    
777        - Fixed PH's badly added libz and libbz2 support.
778        - Fixed a problem with static linking.
779        - Added pcredemo. [But later removed - see 7 below.]
780        - Fixed dftables problem and added an option.
781        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
782            HAVE_LONG_LONG.
783        - Added readline support for pcretest.
784        - Added an listing of the option settings after cmake has run.
785    
786    4.  A user submitted a patch to Makefile that makes it easy to create
787        "pcre.dll" under mingw when using Configure/Make. I added stuff to
788        Makefile.am that cause it to include this special target, without
789        affecting anything else. Note that the same mingw target plus all
790        the other distribution libraries and programs are now supported
791        when configuring with CMake (see 6 below) instead of with
792        Configure/Make.
793    
794    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
795        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
796        exported in the Windows port". It has not yet been confirmed that the patch
797        solves the problem, but it does no harm.
798    
799    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
800        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
801        with CMake, and also correct the comment about stack recursion.
802    
803    7.  Remove the automatic building of pcredemo from the ./configure system and
804        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
805        of a program that users should build themselves after PCRE is installed, so
806        building it automatically is not really right. What is more, it gave
807        trouble in some build environments.
808    
809    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
810    
811    
812    Version 7.5 10-Jan-08
813    ---------------------
814    
815    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
816        values in parens when parsing an RE using the C++ wrapper."
817    
818    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
819        Characters greater than 255 were excluded from the class instead of being
820        included.
821    
822    3.  The same bug as (2) above applied to negated POSIX classes such as
823        [:^space:].
824    
825    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
826        defined or documented. It seems to have been a typo for PCRE_STATIC, so
827        I have changed it.
828    
829    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
830        first named subpattern) and a construct such as (?&a) would reference the
831        first named subpattern whose name started with "a" (in other words, the
832        length check was missing). Both these problems are fixed. "Subpattern name
833        expected" is now given for (?&) (a zero-length name), and this patch also
834        makes it give the same error for \k'' (previously it complained that that
835        was a reference to a non-existent subpattern).
836    
837    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
838        this is right because (?- can be followed by option settings as well as by
839        digits. I have, however, made the messages clearer.
840    
841    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
842        than the number used in the conditional) now cause a compile-time error.
843        This is actually not compatible with Perl, which accepts such patterns, but
844        treats the conditional as always being FALSE (as PCRE used to), but it
845        seems to me that giving a diagnostic is better.
846    
847    8.  Change "alphameric" to the more common word "alphanumeric" in comments
848        and messages.
849    
850    9.  Fix two occurrences of "backslash" in comments that should have been
851        "backspace".
852    
853    10. Remove two redundant lines of code that can never be obeyed (their function
854        was moved elsewhere).
855    
856    11. The program that makes PCRE's Unicode character property table had a bug
857        which caused it to generate incorrect table entries for sequences of
858        characters that have the same character type, but are in different scripts.
859        It amalgamated them into a single range, with the script of the first of
860        them. In other words, some characters were in the wrong script. There were
861        thirteen such cases, affecting characters in the following ranges:
862    
863          U+002b0 - U+002c1
864          U+0060c - U+0060d
865          U+0061e - U+00612
866          U+0064b - U+0065e
867          U+0074d - U+0076d
868          U+01800 - U+01805
869          U+01d00 - U+01d77
870          U+01d9b - U+01dbf
871          U+0200b - U+0200f
872          U+030fc - U+030fe
873          U+03260 - U+0327f
874          U+0fb46 - U+0fbb1
875          U+10450 - U+1049d
876    
877    12. The -o option (show only the matching part of a line) for pcregrep was not
878        compatible with GNU grep in that, if there was more than one match in a
879        line, it showed only the first of them. It now behaves in the same way as
880        GNU grep.
881    
882    13. If the -o and -v options were combined for pcregrep, it printed a blank
883        line for every non-matching line. GNU grep prints nothing, and pcregrep now
884        does the same. The return code can be used to tell if there were any
885        non-matching lines.
886    
887    14. Added --file-offsets and --line-offsets to pcregrep.
888    
889    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
890        infinitely looping recursion. The bug was that positive lookaheads were not
891        being skipped when checking for a possible empty match (negative lookaheads
892        and both kinds of lookbehind were skipped).
893    
894    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
895        inclusion of <windows.h> to before rather than after the definition of
896        INVALID_FILE_ATTRIBUTES (patch from David Byron).
897    
898    17. Specifying a possessive quantifier with a specific limit for a Unicode
899        character property caused pcre_compile() to compile bad code, which led at
900        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
901        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
902        caused the error; without that there was no problem.
903    
904    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
905    
906    19. Added --enable-pcretest-libreadline.
907    
908    20. In pcrecpp.cc, the variable 'count' was incremented twice in
909        RE::GlobalReplace(). As a result, the number of replacements returned was
910        double what it should be. I removed one of the increments, but Craig sent a
911        later patch that removed the other one (the right fix) and added unit tests
912        that check the return values (which was not done before).
913    
914    21. Several CMake things:
915    
916        (1) Arranged that, when cmake is used on Unix, the libraries end up with
917            the names libpcre and libpcreposix, not just pcre and pcreposix.
918    
919        (2) The above change means that pcretest and pcregrep are now correctly
920            linked with the newly-built libraries, not previously installed ones.
921    
922        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
923    
924    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
925        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
926        UTF-8 newline character). The key issue is that the pattern starts .*;
927        this means that the match must be either at the beginning, or after a
928        newline. The bug was in the code for advancing after a failed match and
929        checking that the new position followed a newline. It was not taking
930        account of UTF-8 characters correctly.
931    
932    23. PCRE was behaving differently from Perl in the way it recognized POSIX
933        character classes. PCRE was not treating the sequence [:...:] as a
934        character class unless the ... were all letters. Perl, however, seems to
935        allow any characters between [: and :], though of course it rejects as
936        unknown any "names" that contain non-letters, because all the known class
937        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
938        for example, whereas PCRE did not - it did not recognize a POSIX character
939        class. This seemed a bit dangerous, so the code has been changed to be
940        closer to Perl. The behaviour is not identical to Perl, because PCRE will
941        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
942        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
943        Perl does, and where it didn't before.
944    
945    24. Rewrite so as to remove the single use of %n from pcregrep because in some
946        Windows environments %n is disabled by default.
947    
948    
949    Version 7.4 21-Sep-07
950    ---------------------
951    
952    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
953        means that a class such as [\s] counted as "explicit reference to CR or
954        LF". That isn't really right - the whole point of the change was to try to
955        help when there was an actual mention of one of the two characters. So now
956        the change happens only if \r or \n (or a literal CR or LF) character is
957        encountered.
958    
959    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
960        of both had grown to the point where there were only 3 bits left.
961        Fortunately, there was spare space in the data structure, and so I have
962        moved the internal flags into a new 16-bit field to free up more option
963        bits.
964    
965    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
966        but did not set the internal JCHANGED flag - either of these is enough to
967        control the way the "get" function works - but the PCRE_INFO_JCHANGED
968        facility is supposed to tell if (?J) was ever used, so now (?J) at the
969        start sets both bits.
970    
971    4.  Added options (at build time, compile time, exec time) to change \R from
972        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
973    
974    5.  doc/pcresyntax.html was missing from the distribution.
975    
976    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
977        compatibility, even though it is no longer used.
978    
979    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
980        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
981        windows.h file is present (where different names are used). [This was
982        reversed later after testing - see 16 below.]
983    
984    8.  Changed all #include <config.h> to #include "config.h". There were also
985        some further <pcre.h> cases that I changed to "pcre.h".
986    
987    9.  When pcregrep was used with the --colour option, it missed the line ending
988        sequence off the lines that it output.
989    
990    10. It was pointed out to me that arrays of string pointers cause lots of
991        relocations when a shared library is dynamically loaded. A technique of
992        using a single long string with a table of offsets can drastically reduce
993        these. I have refactored PCRE in four places to do this. The result is
994        dramatic:
995    
996          Originally:                          290
997          After changing UCP table:            187
998          After changing error message table:   43
999          After changing table of "verbs"       36
1000          After changing table of Posix names   22
1001    
1002        Thanks to the folks working on Gregex for glib for this insight.
1003    
1004    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1005        unicode-properties was also set.
1006    
1007    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1008    
1009    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1010        checked only for CRLF.
1011    
1012    14. Added casts to pcretest.c to avoid compiler warnings.
1013    
1014    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1015    
1016    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1017        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1018        entirely. This removes changes made in 7 above.
1019    
1020    17. The CMake files have been updated, and there is now more information about
1021        building with CMake in the NON-UNIX-USE document.
1022    
1023    
1024    Version 7.3 28-Aug-07
1025    ---------------------
1026    
1027     1. In the rejigging of the build system that eventually resulted in 7.1, the
1028        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1029        brackets there is not right, since it causes compilers to look for an
1030        installed pcre.h, not the version that is in the source that is being
1031        compiled (which of course may be different). I have changed it back to:
1032    
1033          #include "pcre.h"
1034    
1035        I have a vague recollection that the change was concerned with compiling in
1036        different directories, but in the new build system, that is taken care of
1037        by the VPATH setting the Makefile.
1038    
1039     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1040        when the subject happened to end in the byte 0x85 (e.g. if the last
1041        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1042        characters but of course it shouldn't be taken as a newline when it is part
1043        of another character. The bug was that, for an unlimited repeat of . in
1044        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1045        characters when looking for a newline.
1046    
1047     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1048    
1049     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1050        in debug output.
1051    
1052     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1053        long printing in the pcrecpp unittest when running under MinGW.
1054    
1055     6. ESC_K was left out of the EBCDIC table.
1056    
1057     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1058        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1059        limit also applies to "virtual nesting" when a pattern is recursive, and in
1060        this case 1000 isn't so big. I have been able to remove this limit at the
1061        expense of backing off one optimization in certain circumstances. Normally,
1062        when pcre_exec() would call its internal match() function recursively and
1063        immediately return the result unconditionally, it uses a "tail recursion"
1064        feature to save stack. However, when a subpattern that can match an empty
1065        string has an unlimited repetition quantifier, it no longer makes this
1066        optimization. That gives it a stack frame in which to save the data for
1067        checking that an empty string has been matched. Previously this was taken
1068        from the 1000-entry workspace that had been reserved. So now there is no
1069        explicit limit, but more stack is used.
1070    
1071     8. Applied Daniel's patches to solve problems with the import/export magic
1072        syntax that is required for Windows, and which was going wrong for the
1073        pcreposix and pcrecpp parts of the library. These were overlooked when this
1074        problem was solved for the main library.
1075    
1076     9. There were some crude static tests to avoid integer overflow when computing
1077        the size of patterns that contain repeated groups with explicit upper
1078        limits. As the maximum quantifier is 65535, the maximum group length was
1079        set at 30,000 so that the product of these two numbers did not overflow a
1080        32-bit integer. However, it turns out that people want to use groups that
1081        are longer than 30,000 bytes (though not repeat them that many times).
1082        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1083        made it possible to implement the integer overflow checks in a much more
1084        dynamic way, which I have now done. The artificial limitation on group
1085        length has been removed - we now have only the limit on the total length of
1086        the compiled pattern, which depends on the LINK_SIZE setting.
1087    
1088    10. Fixed a bug in the documentation for get/copy named substring when
1089        duplicate names are permitted. If none of the named substrings are set, the
1090        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1091        empty string.
1092    
1093    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1094        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1095        because the ] is interpreted as the first data character and the
1096        terminating ] is not found. PCRE has been made compatible with Perl in this
1097        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1098        cause memory overwriting.
1099    
1100    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1101        string has been matched (to stop an infinite loop). It was not recognizing
1102        a conditional subpattern that could match an empty string if that
1103        subpattern was within another subpattern. For example, it looped when
1104        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1105        condition was not nested. This bug has been fixed.
1106    
1107    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1108        past the start of the subject in the presence of bytes with the top bit
1109        set, for example "\x8aBCD".
1110    
1111    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1112        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1113    
1114    14. Optimized (?!) to (*FAIL).
1115    
1116    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1117        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1118        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1119        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1120        does: it's just the validity check that is more restrictive.
1121    
1122    16. Inserted checks for integer overflows during escape sequence (backslash)
1123        processing, and also fixed erroneous offset values for syntax errors during
1124        backslash processing.
1125    
1126    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1127        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1128    
1129    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1130        caused an overrun.
1131    
1132    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1133        something other than just ASCII characters) inside a group that had an
1134        unlimited repeat caused a loop at compile time (while checking to see
1135        whether the group could match an empty string).
1136    
1137    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1138        [\P{Any}] did so. (Error in the code for printing property names.)
1139    
1140    21. An orphan \E inside a character class could cause a crash.
1141    
1142    22. A repeated capturing bracket such as (A)? could cause a wild memory
1143        reference during compilation.
1144    
1145    23. There are several functions in pcre_compile() that scan along a compiled
1146        expression for various reasons (e.g. to see if it's fixed length for look
1147        behind). There were bugs in these functions when a repeated \p or \P was
1148        present in the pattern. These operators have additional parameters compared
1149        with \d, etc, and these were not being taken into account when moving along
1150        the compiled data. Specifically:
1151    
1152        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1153            length.
1154    
1155        (b) An item such as \pL+ within a repeated group could cause crashes or
1156            loops.
1157    
1158        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1159            "reference to non-existent subpattern" error.
1160    
1161        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1162    
1163    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1164        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1165    
1166    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1167    
1168    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1169        character were causing crashes (broken optimization).
1170    
1171    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1172        \p or \P) caused a compile-time loop.
1173    
1174    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1175        break. For example, the unstudied pattern [\r\n]A does not match the string
1176        "\r\nA" because change 7.0/46 below moves the current point on by two
1177        characters after failing to match at the start. However, the pattern \nA
1178        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1179        the same is true. There doesn't seem any very clean way out of this, but
1180        what I have chosen to do makes the common cases work: PCRE now takes note
1181        of whether there can be an explicit match for \r or \n anywhere in the
1182        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1183        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1184        pattern has explicit CR or LF references.
1185    
1186    29. Added (*CR) etc for changing newline setting at start of pattern.
1187    
1188    
1189    Version 7.2 19-Jun-07
1190  ---------------------  ---------------------
1191    
1192   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 11  Version 7.2 01-May-07 Line 1196  Version 7.2 01-May-07
1196      to make them independent of the local environment's newline setting.      to make them independent of the local environment's newline setting.
1197    
1198   3. Add code to configure.ac to remove -g from the CFLAGS default settings.   3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1199    
1200   4. Some of the "internals" tests were previously cut out when the link size   4. Some of the "internals" tests were previously cut out when the link size
1201      was not 2, because the output contained actual offsets. The recent new      was not 2, because the output contained actual offsets. The recent new
1202      "Z" feature of pcretest means that these can be cut out, making the tests      "Z" feature of pcretest means that these can be cut out, making the tests
1203      usable with all link sizes.      usable with all link sizes.
1204    
1205     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1206        stack recursion. This gives a massive performance boost under BSD, but just
1207        a small improvement under Linux. However, it saves one field in the frame
1208        in all cases.
1209    
1210     6. Added more features from the forthcoming Perl 5.10:
1211    
1212        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1213            recursion call. It refers to the nth most recently opened parentheses.
1214    
1215        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1216            to be opened parentheses.
1217    
1218        (c) Conditions that refer to capturing parentheses can be specified
1219            relatively, for example, (?(-2)... or (?(+3)...
1220    
1221        (d) \K resets the start of the current match so that everything before
1222            is not part of it.
1223    
1224        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1225    
1226        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1227            reference syntax.
1228    
1229        (g) (?| introduces a group in which the numbering of parentheses in each
1230            alternative starts with the same number.
1231    
1232        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1233    
1234     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1235        PCRE_INFO_JCHANGED.
1236    
1237     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1238        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1239        for detecting groups that can match an empty string.
1240    
1241     9. A pattern with a very large number of alternatives (more than several
1242        hundred) was running out of internal workspace during the pre-compile
1243        phase, where pcre_compile() figures out how much memory will be needed. A
1244        bit of new cunning has reduced the workspace needed for groups with
1245        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1246        workspace instead of running out of the 4096 that are available.
1247    
1248    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1249    
1250    11. Applied patch from Google to remove an optimization that didn't quite work.
1251        The report of the bug said:
1252    
1253          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1254          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1255          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1256    
1257    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1258        it matched the wrong number of bytes.
1259    
1260    
1261  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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