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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 05-June-07  Version 7.9 xx-xxx-09
5    ---------------------
6    
7    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
8        (pcretest), all targets were linked against these libraries. This included
9        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
10        libraries. This caused unwanted dependencies to be created. This problem
11        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
12        pcretest is linked with readline.
13    
14    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
15        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
16        moved outside it again, because FALSE and TRUE are already defined in AIX,
17        but BOOL is not.
18    
19    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
20        PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.
21    
22    4.  The pcregrep documentation said spaces were inserted as well as colons (or
23        hyphens) following file names and line numbers when outputting matching
24        lines. This is not true; no spaces are inserted. I have also clarified the
25        wording for the --colour (or --color) option.
26    
27    5.  In pcregrep, when --colour was used with -o, the list of matching strings
28        was not coloured; this is different to GNU grep, so I have changed it to be
29        the same.
30    
31    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
32        each matching line was coloured. Now it goes on to look for further matches
33        of any of the test patterns, which is the same behaviour as GNU grep.
34    
35    7.  A pattern that could match an empty string could cause pcregrep to loop; it
36        doesn't make sense to accept an empty string match in pcregrep, so I have
37        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38        seems to be how GNU grep behaves.
39    
40    
41    Version 7.8 05-Sep-08
42    ---------------------
43    
44    1.  Replaced UCP searching code with optimized version as implemented for Ad
45        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
46        stage table and inline lookup instead of a function, giving speed ups of 2
47        to 5 times on some simple patterns that I tested. Permission was given to
48        distribute the MultiStage2.py script that generates the tables (it's not in
49        the tarball, but is in the Subversion repository).
50    
51    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
52        scripts.
53    
54    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
55        a group with a zero qualifier. The result of the study could be incorrect,
56        or the function might crash, depending on the pattern.
57    
58    4.  Caseless matching was not working for non-ASCII characters in back
59        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
60        It now works when Unicode Property Support is available.
61    
62    5.  In pcretest, an escape such as \x{de} in the data was always generating
63        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
64        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
65        truncation.
66    
67    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
68    
69    7.  Added two (int) casts to pcregrep when printing the difference of two
70        pointers, in case they are 64-bit values.
71    
72    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
73        test 2 if it fails.
74    
75    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
76        and a #define of that name to empty if it is not externally set. This is to
77        allow users of MSVC to set it if necessary.
78    
79    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
80        the convenience functions in the pcre_get.c source file.
81    
82    11. An option change at the start of a pattern that had top-level alternatives
83        could cause overwriting and/or a crash. This command provoked a crash in
84        some environments:
85    
86          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
87    
88        This potential security problem was recorded as CVE-2008-2371.
89    
90    12. For a pattern where the match had to start at the beginning or immediately
91        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
92        pcre_dfa_exec() could read past the end of the passed subject if there was
93        no match. To help with detecting such bugs (e.g. with valgrind), I modified
94        pcretest so that it places the subject at the end of its malloc-ed buffer.
95    
96    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
97        exec() might read past the end of the data buffer in UTF-8 mode.
98    
99    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
100        the data contained the byte 0x85 as part of a UTF-8 character within its
101        first line. This applied both to normal and DFA matching.
102    
103    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
104        /^[^d]*?$/8 failed to match "abc".
105    
106    16. Added a missing copyright notice to pcrecpp_internal.h.
107    
108    17. Make it more clear in the documentation that values returned from
109        pcre_exec() in ovector are byte offsets, not character counts.
110    
111    18. Tidied a few places to stop certain compilers from issuing warnings.
112    
113    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
114        supplied by Stefan Weber. I made a further small update for 7.8 because
115        there is a change of source arrangements: the pcre_searchfuncs.c module is
116        replaced by pcre_ucd.c.
117    
118    
119    Version 7.7 07-May-08
120    ---------------------
121    
122    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
123        a string to a long long, pretend we don't even have a long long." This is
124        done by checking for the strtoq, strtoll, and _strtoi64 functions.
125    
126    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
127        pre-7.6 versions, which defined a global no_arg variable instead of putting
128        it in the RE class. (See also #8 below.)
129    
130    3.  Remove a line of dead code, identified by coverity and reported by Nuno
131        Lopes.
132    
133    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
134    
135        (1) The include/exclude patterns were being applied to the whole pathnames
136            of files, instead of just to the final components.
137    
138        (2) If there was more than one level of directory, the subdirectories were
139            skipped unless they satisfied the include/exclude conditions. This is
140            inconsistent with GNU grep (and could even be seen as contrary to the
141            pcregrep specification - which I improved to make it absolutely clear).
142            The action now is always to scan all levels of directory, and just
143            apply the include/exclude patterns to regular files.
144    
145    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
146        --exclude_dir in the tests to avoid scanning .svn directories.
147    
148    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
149        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
150        doesn't support NULs in patterns.
151    
152    7.  Added some missing "const"s to declarations of static tables in
153        pcre_compile.c and pcre_dfa_exec.c.
154    
155    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
156        caused by fix #2  above. (Subsequently also a second patch to fix the
157        first patch. And a third patch - this was a messy problem.)
158    
159    9.  Applied Craig's patch to remove the use of push_back().
160    
161    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
162        matching function regexec().
163    
164    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
165        which, however, unlike Perl's \g{...}, are subroutine calls, not back
166        references. PCRE supports relative numbers with this syntax (I don't think
167        Oniguruma does).
168    
169    12. Previously, a group with a zero repeat such as (...){0} was completely
170        omitted from the compiled regex. However, this means that if the group
171        was called as a subroutine from elsewhere in the pattern, things went wrong
172        (an internal error was given). Such groups are now left in the compiled
173        pattern, with a new opcode that causes them to be skipped at execution
174        time.
175    
176    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
177        to the way PCRE behaves:
178    
179        (a) A lone ] character is dis-allowed (Perl treats it as data).
180    
181        (b) A back reference to an unmatched subpattern matches an empty string
182            (Perl fails the current match path).
183    
184        (c) A data ] in a character class must be notated as \] because if the
185            first data character in a class is ], it defines an empty class. (In
186            Perl it is not possible to have an empty class.) The empty class []
187            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
188            The negative empty class [^] matches any one character, independently
189            of the DOTALL setting.
190    
191    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
192        non-existent subpattern following a character class starting with ']' and
193        containing () gave an internal compiling error instead of "reference to
194        non-existent subpattern". Fortunately, when the pattern did exist, the
195        compiled code was correct. (When scanning forwards to check for the
196        existencd of the subpattern, it was treating the data ']' as terminating
197        the class, so got the count wrong. When actually compiling, the reference
198        was subsequently set up correctly.)
199    
200    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
201        it was being rejected as not supported by pcre_dfa_exec(), even though
202        other assertions are supported. I have made pcre_dfa_exec() support
203        (*FAIL).
204    
205    16. The implementation of 13c above involved the invention of a new opcode,
206        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
207        cannot be changed at match time, I realized I could make a small
208        improvement to matching performance by compiling OP_ALLANY instead of
209        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
210        on the OP_ANY path.
211    
212    17. Compiling pcretest on Windows with readline support failed without the
213        following two fixes: (1) Make the unistd.h include conditional on
214        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
215    
216    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
217        ncurses library to be included for pcretest when ReadLine support is
218        requested, but also to allow for it to be overridden. This patch came from
219        Daniel Bergström.
220    
221    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
222        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
223        any errors with the current Unicode tables. Thanks to Peter Kankowski for
224        spotting this.
225    
226    
227    Version 7.6 28-Jan-08
228    ---------------------
229    
230    1.  A character class containing a very large number of characters with
231        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
232        overflow.
233    
234    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
235        HAVE_LONG_LONG is not defined.
236    
237    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
238        bring them up to date and include new features. This patch includes:
239    
240        - Fixed PH's badly added libz and libbz2 support.
241        - Fixed a problem with static linking.
242        - Added pcredemo. [But later removed - see 7 below.]
243        - Fixed dftables problem and added an option.
244        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
245            HAVE_LONG_LONG.
246        - Added readline support for pcretest.
247        - Added an listing of the option settings after cmake has run.
248    
249    4.  A user submitted a patch to Makefile that makes it easy to create
250        "pcre.dll" under mingw when using Configure/Make. I added stuff to
251        Makefile.am that cause it to include this special target, without
252        affecting anything else. Note that the same mingw target plus all
253        the other distribution libraries and programs are now supported
254        when configuring with CMake (see 6 below) instead of with
255        Configure/Make.
256    
257    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
258        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
259        exported in the Windows port". It has not yet been confirmed that the patch
260        solves the problem, but it does no harm.
261    
262    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
263        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
264        with CMake, and also correct the comment about stack recursion.
265    
266    7.  Remove the automatic building of pcredemo from the ./configure system and
267        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
268        of a program that users should build themselves after PCRE is installed, so
269        building it automatically is not really right. What is more, it gave
270        trouble in some build environments.
271    
272    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
273    
274    
275    Version 7.5 10-Jan-08
276    ---------------------
277    
278    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
279        values in parens when parsing an RE using the C++ wrapper."
280    
281    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
282        Characters greater than 255 were excluded from the class instead of being
283        included.
284    
285    3.  The same bug as (2) above applied to negated POSIX classes such as
286        [:^space:].
287    
288    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
289        defined or documented. It seems to have been a typo for PCRE_STATIC, so
290        I have changed it.
291    
292    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
293        first named subpattern) and a construct such as (?&a) would reference the
294        first named subpattern whose name started with "a" (in other words, the
295        length check was missing). Both these problems are fixed. "Subpattern name
296        expected" is now given for (?&) (a zero-length name), and this patch also
297        makes it give the same error for \k'' (previously it complained that that
298        was a reference to a non-existent subpattern).
299    
300    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
301        this is right because (?- can be followed by option settings as well as by
302        digits. I have, however, made the messages clearer.
303    
304    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
305        than the number used in the conditional) now cause a compile-time error.
306        This is actually not compatible with Perl, which accepts such patterns, but
307        treats the conditional as always being FALSE (as PCRE used to), but it
308        seems to me that giving a diagnostic is better.
309    
310    8.  Change "alphameric" to the more common word "alphanumeric" in comments
311        and messages.
312    
313    9.  Fix two occurrences of "backslash" in comments that should have been
314        "backspace".
315    
316    10. Remove two redundant lines of code that can never be obeyed (their function
317        was moved elsewhere).
318    
319    11. The program that makes PCRE's Unicode character property table had a bug
320        which caused it to generate incorrect table entries for sequences of
321        characters that have the same character type, but are in different scripts.
322        It amalgamated them into a single range, with the script of the first of
323        them. In other words, some characters were in the wrong script. There were
324        thirteen such cases, affecting characters in the following ranges:
325    
326          U+002b0 - U+002c1
327          U+0060c - U+0060d
328          U+0061e - U+00612
329          U+0064b - U+0065e
330          U+0074d - U+0076d
331          U+01800 - U+01805
332          U+01d00 - U+01d77
333          U+01d9b - U+01dbf
334          U+0200b - U+0200f
335          U+030fc - U+030fe
336          U+03260 - U+0327f
337          U+0fb46 - U+0fbb1
338          U+10450 - U+1049d
339    
340    12. The -o option (show only the matching part of a line) for pcregrep was not
341        compatible with GNU grep in that, if there was more than one match in a
342        line, it showed only the first of them. It now behaves in the same way as
343        GNU grep.
344    
345    13. If the -o and -v options were combined for pcregrep, it printed a blank
346        line for every non-matching line. GNU grep prints nothing, and pcregrep now
347        does the same. The return code can be used to tell if there were any
348        non-matching lines.
349    
350    14. Added --file-offsets and --line-offsets to pcregrep.
351    
352    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
353        infinitely looping recursion. The bug was that positive lookaheads were not
354        being skipped when checking for a possible empty match (negative lookaheads
355        and both kinds of lookbehind were skipped).
356    
357    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
358        inclusion of <windows.h> to before rather than after the definition of
359        INVALID_FILE_ATTRIBUTES (patch from David Byron).
360    
361    17. Specifying a possessive quantifier with a specific limit for a Unicode
362        character property caused pcre_compile() to compile bad code, which led at
363        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
364        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
365        caused the error; without that there was no problem.
366    
367    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
368    
369    19. Added --enable-pcretest-libreadline.
370    
371    20. In pcrecpp.cc, the variable 'count' was incremented twice in
372        RE::GlobalReplace(). As a result, the number of replacements returned was
373        double what it should be. I removed one of the increments, but Craig sent a
374        later patch that removed the other one (the right fix) and added unit tests
375        that check the return values (which was not done before).
376    
377    21. Several CMake things:
378    
379        (1) Arranged that, when cmake is used on Unix, the libraries end up with
380            the names libpcre and libpcreposix, not just pcre and pcreposix.
381    
382        (2) The above change means that pcretest and pcregrep are now correctly
383            linked with the newly-built libraries, not previously installed ones.
384    
385        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
386    
387    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
388        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
389        UTF-8 newline character). The key issue is that the pattern starts .*;
390        this means that the match must be either at the beginning, or after a
391        newline. The bug was in the code for advancing after a failed match and
392        checking that the new position followed a newline. It was not taking
393        account of UTF-8 characters correctly.
394    
395    23. PCRE was behaving differently from Perl in the way it recognized POSIX
396        character classes. PCRE was not treating the sequence [:...:] as a
397        character class unless the ... were all letters. Perl, however, seems to
398        allow any characters between [: and :], though of course it rejects as
399        unknown any "names" that contain non-letters, because all the known class
400        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
401        for example, whereas PCRE did not - it did not recognize a POSIX character
402        class. This seemed a bit dangerous, so the code has been changed to be
403        closer to Perl. The behaviour is not identical to Perl, because PCRE will
404        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
405        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
406        Perl does, and where it didn't before.
407    
408    24. Rewrite so as to remove the single use of %n from pcregrep because in some
409        Windows environments %n is disabled by default.
410    
411    
412    Version 7.4 21-Sep-07
413    ---------------------
414    
415    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
416        means that a class such as [\s] counted as "explicit reference to CR or
417        LF". That isn't really right - the whole point of the change was to try to
418        help when there was an actual mention of one of the two characters. So now
419        the change happens only if \r or \n (or a literal CR or LF) character is
420        encountered.
421    
422    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
423        of both had grown to the point where there were only 3 bits left.
424        Fortunately, there was spare space in the data structure, and so I have
425        moved the internal flags into a new 16-bit field to free up more option
426        bits.
427    
428    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
429        but did not set the internal JCHANGED flag - either of these is enough to
430        control the way the "get" function works - but the PCRE_INFO_JCHANGED
431        facility is supposed to tell if (?J) was ever used, so now (?J) at the
432        start sets both bits.
433    
434    4.  Added options (at build time, compile time, exec time) to change \R from
435        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
436    
437    5.  doc/pcresyntax.html was missing from the distribution.
438    
439    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
440        compatibility, even though it is no longer used.
441    
442    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
443        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
444        windows.h file is present (where different names are used). [This was
445        reversed later after testing - see 16 below.]
446    
447    8.  Changed all #include <config.h> to #include "config.h". There were also
448        some further <pcre.h> cases that I changed to "pcre.h".
449    
450    9.  When pcregrep was used with the --colour option, it missed the line ending
451        sequence off the lines that it output.
452    
453    10. It was pointed out to me that arrays of string pointers cause lots of
454        relocations when a shared library is dynamically loaded. A technique of
455        using a single long string with a table of offsets can drastically reduce
456        these. I have refactored PCRE in four places to do this. The result is
457        dramatic:
458    
459          Originally:                          290
460          After changing UCP table:            187
461          After changing error message table:   43
462          After changing table of "verbs"       36
463          After changing table of Posix names   22
464    
465        Thanks to the folks working on Gregex for glib for this insight.
466    
467    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
468        unicode-properties was also set.
469    
470    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
471    
472    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
473        checked only for CRLF.
474    
475    14. Added casts to pcretest.c to avoid compiler warnings.
476    
477    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
478    
479    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
480        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
481        entirely. This removes changes made in 7 above.
482    
483    17. The CMake files have been updated, and there is now more information about
484        building with CMake in the NON-UNIX-USE document.
485    
486    
487    Version 7.3 28-Aug-07
488    ---------------------
489    
490     1. In the rejigging of the build system that eventually resulted in 7.1, the
491        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
492        brackets there is not right, since it causes compilers to look for an
493        installed pcre.h, not the version that is in the source that is being
494        compiled (which of course may be different). I have changed it back to:
495    
496          #include "pcre.h"
497    
498        I have a vague recollection that the change was concerned with compiling in
499        different directories, but in the new build system, that is taken care of
500        by the VPATH setting the Makefile.
501    
502     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
503        when the subject happened to end in the byte 0x85 (e.g. if the last
504        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
505        characters but of course it shouldn't be taken as a newline when it is part
506        of another character. The bug was that, for an unlimited repeat of . in
507        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
508        characters when looking for a newline.
509    
510     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
511    
512     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
513        in debug output.
514    
515     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
516        long printing in the pcrecpp unittest when running under MinGW.
517    
518     6. ESC_K was left out of the EBCDIC table.
519    
520     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
521        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
522        limit also applies to "virtual nesting" when a pattern is recursive, and in
523        this case 1000 isn't so big. I have been able to remove this limit at the
524        expense of backing off one optimization in certain circumstances. Normally,
525        when pcre_exec() would call its internal match() function recursively and
526        immediately return the result unconditionally, it uses a "tail recursion"
527        feature to save stack. However, when a subpattern that can match an empty
528        string has an unlimited repetition quantifier, it no longer makes this
529        optimization. That gives it a stack frame in which to save the data for
530        checking that an empty string has been matched. Previously this was taken
531        from the 1000-entry workspace that had been reserved. So now there is no
532        explicit limit, but more stack is used.
533    
534     8. Applied Daniel's patches to solve problems with the import/export magic
535        syntax that is required for Windows, and which was going wrong for the
536        pcreposix and pcrecpp parts of the library. These were overlooked when this
537        problem was solved for the main library.
538    
539     9. There were some crude static tests to avoid integer overflow when computing
540        the size of patterns that contain repeated groups with explicit upper
541        limits. As the maximum quantifier is 65535, the maximum group length was
542        set at 30,000 so that the product of these two numbers did not overflow a
543        32-bit integer. However, it turns out that people want to use groups that
544        are longer than 30,000 bytes (though not repeat them that many times).
545        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
546        made it possible to implement the integer overflow checks in a much more
547        dynamic way, which I have now done. The artificial limitation on group
548        length has been removed - we now have only the limit on the total length of
549        the compiled pattern, which depends on the LINK_SIZE setting.
550    
551    10. Fixed a bug in the documentation for get/copy named substring when
552        duplicate names are permitted. If none of the named substrings are set, the
553        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
554        empty string.
555    
556    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
557        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
558        because the ] is interpreted as the first data character and the
559        terminating ] is not found. PCRE has been made compatible with Perl in this
560        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
561        cause memory overwriting.
562    
563    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
564        string has been matched (to stop an infinite loop). It was not recognizing
565        a conditional subpattern that could match an empty string if that
566        subpattern was within another subpattern. For example, it looped when
567        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
568        condition was not nested. This bug has been fixed.
569    
570    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
571        past the start of the subject in the presence of bytes with the top bit
572        set, for example "\x8aBCD".
573    
574    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
575        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
576    
577    14. Optimized (?!) to (*FAIL).
578    
579    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
580        This restricts code points to be within the range 0 to 0x10FFFF, excluding
581        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
582        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
583        does: it's just the validity check that is more restrictive.
584    
585    16. Inserted checks for integer overflows during escape sequence (backslash)
586        processing, and also fixed erroneous offset values for syntax errors during
587        backslash processing.
588    
589    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
590        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
591    
592    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
593        caused an overrun.
594    
595    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
596        something other than just ASCII characters) inside a group that had an
597        unlimited repeat caused a loop at compile time (while checking to see
598        whether the group could match an empty string).
599    
600    20. Debugging a pattern containing \p or \P could cause a crash. For example,
601        [\P{Any}] did so. (Error in the code for printing property names.)
602    
603    21. An orphan \E inside a character class could cause a crash.
604    
605    22. A repeated capturing bracket such as (A)? could cause a wild memory
606        reference during compilation.
607    
608    23. There are several functions in pcre_compile() that scan along a compiled
609        expression for various reasons (e.g. to see if it's fixed length for look
610        behind). There were bugs in these functions when a repeated \p or \P was
611        present in the pattern. These operators have additional parameters compared
612        with \d, etc, and these were not being taken into account when moving along
613        the compiled data. Specifically:
614    
615        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
616            length.
617    
618        (b) An item such as \pL+ within a repeated group could cause crashes or
619            loops.
620    
621        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
622            "reference to non-existent subpattern" error.
623    
624        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
625    
626    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
627        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
628    
629    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
630    
631    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
632        character were causing crashes (broken optimization).
633    
634    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
635        \p or \P) caused a compile-time loop.
636    
637    28. More problems have arisen in unanchored patterns when CRLF is a valid line
638        break. For example, the unstudied pattern [\r\n]A does not match the string
639        "\r\nA" because change 7.0/46 below moves the current point on by two
640        characters after failing to match at the start. However, the pattern \nA
641        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
642        the same is true. There doesn't seem any very clean way out of this, but
643        what I have chosen to do makes the common cases work: PCRE now takes note
644        of whether there can be an explicit match for \r or \n anywhere in the
645        pattern, and if so, 7.0/46 no longer applies. As part of this change,
646        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
647        pattern has explicit CR or LF references.
648    
649    29. Added (*CR) etc for changing newline setting at start of pattern.
650    
651    
652    Version 7.2 19-Jun-07
653  ---------------------  ---------------------
654    
655   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 40  Version 7.2 05-June-07 Line 688  Version 7.2 05-June-07
688    
689      (f) \g{name} is another synonym - part of Perl 5.10's unification of      (f) \g{name} is another synonym - part of Perl 5.10's unification of
690          reference syntax.          reference syntax.
691    
692      (g) (?| introduces a group in which the numbering of parentheses in each      (g) (?| introduces a group in which the numbering of parentheses in each
693          alternative starts with the same number.          alternative starts with the same number.
694    
695        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
696    
697   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
698      PCRE_INFO_JCHANGED.      PCRE_INFO_JCHANGED.
# Line 57  Version 7.2 05-June-07 Line 707  Version 7.2 05-June-07
707      bit of new cunning has reduced the workspace needed for groups with      bit of new cunning has reduced the workspace needed for groups with
708      alternatives. The 1000-alternative test pattern now uses 12 bytes of      alternatives. The 1000-alternative test pattern now uses 12 bytes of
709      workspace instead of running out of the 4096 that are available.      workspace instead of running out of the 4096 that are available.
710    
711  10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.  10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
712    
713    11. Applied patch from Google to remove an optimization that didn't quite work.
714        The report of the bug said:
715    
716          pcrecpp::RE("a*").FullMatch("aaa") matches, while
717          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
718          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
719    
720    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
721        it matched the wrong number of bytes.
722    
723    
724  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
725  ---------------------  ---------------------

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