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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-07  Version 7.9 xx-xxx-09
5    ---------------------
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.
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.
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.
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.
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.
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.
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.
40    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41        start or after a newline", because the conditional assertion was not being
42        correctly handled. The rule now is that both the assertion and what follows
43        in the first alternative must satisfy the test.
45    9.  If auto-callout was enabled in a pattern with a conditional group, PCRE
46        could crash during matching.
48    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
49        used for matching.
52    Version 7.8 05-Sep-08
53    ---------------------
55    1.  Replaced UCP searching code with optimized version as implemented for Ad
56        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
57        stage table and inline lookup instead of a function, giving speed ups of 2
58        to 5 times on some simple patterns that I tested. Permission was given to
59        distribute the MultiStage2.py script that generates the tables (it's not in
60        the tarball, but is in the Subversion repository).
62    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
63        scripts.
65    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
66        a group with a zero qualifier. The result of the study could be incorrect,
67        or the function might crash, depending on the pattern.
69    4.  Caseless matching was not working for non-ASCII characters in back
70        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
71        It now works when Unicode Property Support is available.
73    5.  In pcretest, an escape such as \x{de} in the data was always generating
74        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
75        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
76        truncation.
78    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
80    7.  Added two (int) casts to pcregrep when printing the difference of two
81        pointers, in case they are 64-bit values.
83    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
84        test 2 if it fails.
86    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
87        and a #define of that name to empty if it is not externally set. This is to
88        allow users of MSVC to set it if necessary.
90    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
91        the convenience functions in the pcre_get.c source file.
93    11. An option change at the start of a pattern that had top-level alternatives
94        could cause overwriting and/or a crash. This command provoked a crash in
95        some environments:
97          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
99        This potential security problem was recorded as CVE-2008-2371.
101    12. For a pattern where the match had to start at the beginning or immediately
102        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
103        pcre_dfa_exec() could read past the end of the passed subject if there was
104        no match. To help with detecting such bugs (e.g. with valgrind), I modified
105        pcretest so that it places the subject at the end of its malloc-ed buffer.
107    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
108        exec() might read past the end of the data buffer in UTF-8 mode.
110    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
111        the data contained the byte 0x85 as part of a UTF-8 character within its
112        first line. This applied both to normal and DFA matching.
114    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
115        /^[^d]*?$/8 failed to match "abc".
117    16. Added a missing copyright notice to pcrecpp_internal.h.
119    17. Make it more clear in the documentation that values returned from
120        pcre_exec() in ovector are byte offsets, not character counts.
122    18. Tidied a few places to stop certain compilers from issuing warnings.
124    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
125        supplied by Stefan Weber. I made a further small update for 7.8 because
126        there is a change of source arrangements: the pcre_searchfuncs.c module is
127        replaced by pcre_ucd.c.
130    Version 7.7 07-May-08
131    ---------------------
133    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
134        a string to a long long, pretend we don't even have a long long." This is
135        done by checking for the strtoq, strtoll, and _strtoi64 functions.
137    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
138        pre-7.6 versions, which defined a global no_arg variable instead of putting
139        it in the RE class. (See also #8 below.)
141    3.  Remove a line of dead code, identified by coverity and reported by Nuno
142        Lopes.
144    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
146        (1) The include/exclude patterns were being applied to the whole pathnames
147            of files, instead of just to the final components.
149        (2) If there was more than one level of directory, the subdirectories were
150            skipped unless they satisfied the include/exclude conditions. This is
151            inconsistent with GNU grep (and could even be seen as contrary to the
152            pcregrep specification - which I improved to make it absolutely clear).
153            The action now is always to scan all levels of directory, and just
154            apply the include/exclude patterns to regular files.
156    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
157        --exclude_dir in the tests to avoid scanning .svn directories.
159    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
160        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
161        doesn't support NULs in patterns.
163    7.  Added some missing "const"s to declarations of static tables in
164        pcre_compile.c and pcre_dfa_exec.c.
166    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
167        caused by fix #2  above. (Subsequently also a second patch to fix the
168        first patch. And a third patch - this was a messy problem.)
170    9.  Applied Craig's patch to remove the use of push_back().
172    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
173        matching function regexec().
175    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
176        which, however, unlike Perl's \g{...}, are subroutine calls, not back
177        references. PCRE supports relative numbers with this syntax (I don't think
178        Oniguruma does).
180    12. Previously, a group with a zero repeat such as (...){0} was completely
181        omitted from the compiled regex. However, this means that if the group
182        was called as a subroutine from elsewhere in the pattern, things went wrong
183        (an internal error was given). Such groups are now left in the compiled
184        pattern, with a new opcode that causes them to be skipped at execution
185        time.
187    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
188        to the way PCRE behaves:
190        (a) A lone ] character is dis-allowed (Perl treats it as data).
192        (b) A back reference to an unmatched subpattern matches an empty string
193            (Perl fails the current match path).
195        (c) A data ] in a character class must be notated as \] because if the
196            first data character in a class is ], it defines an empty class. (In
197            Perl it is not possible to have an empty class.) The empty class []
198            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
199            The negative empty class [^] matches any one character, independently
200            of the DOTALL setting.
202    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
203        non-existent subpattern following a character class starting with ']' and
204        containing () gave an internal compiling error instead of "reference to
205        non-existent subpattern". Fortunately, when the pattern did exist, the
206        compiled code was correct. (When scanning forwards to check for the
207        existencd of the subpattern, it was treating the data ']' as terminating
208        the class, so got the count wrong. When actually compiling, the reference
209        was subsequently set up correctly.)
211    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
212        it was being rejected as not supported by pcre_dfa_exec(), even though
213        other assertions are supported. I have made pcre_dfa_exec() support
214        (*FAIL).
216    16. The implementation of 13c above involved the invention of a new opcode,
217        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
218        cannot be changed at match time, I realized I could make a small
219        improvement to matching performance by compiling OP_ALLANY instead of
220        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
221        on the OP_ANY path.
223    17. Compiling pcretest on Windows with readline support failed without the
224        following two fixes: (1) Make the unistd.h include conditional on
225        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
227    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
228        ncurses library to be included for pcretest when ReadLine support is
229        requested, but also to allow for it to be overridden. This patch came from
230        Daniel Bergström.
232    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
233        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
234        any errors with the current Unicode tables. Thanks to Peter Kankowski for
235        spotting this.
238    Version 7.6 28-Jan-08
239    ---------------------
241    1.  A character class containing a very large number of characters with
242        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
243        overflow.
245    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
246        HAVE_LONG_LONG is not defined.
248    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
249        bring them up to date and include new features. This patch includes:
251        - Fixed PH's badly added libz and libbz2 support.
252        - Fixed a problem with static linking.
253        - Added pcredemo. [But later removed - see 7 below.]
254        - Fixed dftables problem and added an option.
255        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
256            HAVE_LONG_LONG.
257        - Added readline support for pcretest.
258        - Added an listing of the option settings after cmake has run.
260    4.  A user submitted a patch to Makefile that makes it easy to create
261        "pcre.dll" under mingw when using Configure/Make. I added stuff to
262        Makefile.am that cause it to include this special target, without
263        affecting anything else. Note that the same mingw target plus all
264        the other distribution libraries and programs are now supported
265        when configuring with CMake (see 6 below) instead of with
266        Configure/Make.
268    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
269        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
270        exported in the Windows port". It has not yet been confirmed that the patch
271        solves the problem, but it does no harm.
273    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
274        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
275        with CMake, and also correct the comment about stack recursion.
277    7.  Remove the automatic building of pcredemo from the ./configure system and
278        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
279        of a program that users should build themselves after PCRE is installed, so
280        building it automatically is not really right. What is more, it gave
281        trouble in some build environments.
283    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
286    Version 7.5 10-Jan-08
287    ---------------------
289    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
290        values in parens when parsing an RE using the C++ wrapper."
292    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
293        Characters greater than 255 were excluded from the class instead of being
294        included.
296    3.  The same bug as (2) above applied to negated POSIX classes such as
297        [:^space:].
299    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
300        defined or documented. It seems to have been a typo for PCRE_STATIC, so
301        I have changed it.
303    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
304        first named subpattern) and a construct such as (?&a) would reference the
305        first named subpattern whose name started with "a" (in other words, the
306        length check was missing). Both these problems are fixed. "Subpattern name
307        expected" is now given for (?&) (a zero-length name), and this patch also
308        makes it give the same error for \k'' (previously it complained that that
309        was a reference to a non-existent subpattern).
311    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
312        this is right because (?- can be followed by option settings as well as by
313        digits. I have, however, made the messages clearer.
315    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
316        than the number used in the conditional) now cause a compile-time error.
317        This is actually not compatible with Perl, which accepts such patterns, but
318        treats the conditional as always being FALSE (as PCRE used to), but it
319        seems to me that giving a diagnostic is better.
321    8.  Change "alphameric" to the more common word "alphanumeric" in comments
322        and messages.
324    9.  Fix two occurrences of "backslash" in comments that should have been
325        "backspace".
327    10. Remove two redundant lines of code that can never be obeyed (their function
328        was moved elsewhere).
330    11. The program that makes PCRE's Unicode character property table had a bug
331        which caused it to generate incorrect table entries for sequences of
332        characters that have the same character type, but are in different scripts.
333        It amalgamated them into a single range, with the script of the first of
334        them. In other words, some characters were in the wrong script. There were
335        thirteen such cases, affecting characters in the following ranges:
337          U+002b0 - U+002c1
338          U+0060c - U+0060d
339          U+0061e - U+00612
340          U+0064b - U+0065e
341          U+0074d - U+0076d
342          U+01800 - U+01805
343          U+01d00 - U+01d77
344          U+01d9b - U+01dbf
345          U+0200b - U+0200f
346          U+030fc - U+030fe
347          U+03260 - U+0327f
348          U+0fb46 - U+0fbb1
349          U+10450 - U+1049d
351    12. The -o option (show only the matching part of a line) for pcregrep was not
352        compatible with GNU grep in that, if there was more than one match in a
353        line, it showed only the first of them. It now behaves in the same way as
354        GNU grep.
356    13. If the -o and -v options were combined for pcregrep, it printed a blank
357        line for every non-matching line. GNU grep prints nothing, and pcregrep now
358        does the same. The return code can be used to tell if there were any
359        non-matching lines.
361    14. Added --file-offsets and --line-offsets to pcregrep.
363    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
364        infinitely looping recursion. The bug was that positive lookaheads were not
365        being skipped when checking for a possible empty match (negative lookaheads
366        and both kinds of lookbehind were skipped).
368    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
369        inclusion of <windows.h> to before rather than after the definition of
370        INVALID_FILE_ATTRIBUTES (patch from David Byron).
372    17. Specifying a possessive quantifier with a specific limit for a Unicode
373        character property caused pcre_compile() to compile bad code, which led at
374        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
375        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
376        caused the error; without that there was no problem.
378    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
380    19. Added --enable-pcretest-libreadline.
382    20. In pcrecpp.cc, the variable 'count' was incremented twice in
383        RE::GlobalReplace(). As a result, the number of replacements returned was
384        double what it should be. I removed one of the increments, but Craig sent a
385        later patch that removed the other one (the right fix) and added unit tests
386        that check the return values (which was not done before).
388    21. Several CMake things:
390        (1) Arranged that, when cmake is used on Unix, the libraries end up with
391            the names libpcre and libpcreposix, not just pcre and pcreposix.
393        (2) The above change means that pcretest and pcregrep are now correctly
394            linked with the newly-built libraries, not previously installed ones.
398    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
399        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
400        UTF-8 newline character). The key issue is that the pattern starts .*;
401        this means that the match must be either at the beginning, or after a
402        newline. The bug was in the code for advancing after a failed match and
403        checking that the new position followed a newline. It was not taking
404        account of UTF-8 characters correctly.
406    23. PCRE was behaving differently from Perl in the way it recognized POSIX
407        character classes. PCRE was not treating the sequence [:...:] as a
408        character class unless the ... were all letters. Perl, however, seems to
409        allow any characters between [: and :], though of course it rejects as
410        unknown any "names" that contain non-letters, because all the known class
411        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
412        for example, whereas PCRE did not - it did not recognize a POSIX character
413        class. This seemed a bit dangerous, so the code has been changed to be
414        closer to Perl. The behaviour is not identical to Perl, because PCRE will
415        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
416        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
417        Perl does, and where it didn't before.
419    24. Rewrite so as to remove the single use of %n from pcregrep because in some
420        Windows environments %n is disabled by default.
423    Version 7.4 21-Sep-07
424    ---------------------
426    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
427        means that a class such as [\s] counted as "explicit reference to CR or
428        LF". That isn't really right - the whole point of the change was to try to
429        help when there was an actual mention of one of the two characters. So now
430        the change happens only if \r or \n (or a literal CR or LF) character is
431        encountered.
433    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
434        of both had grown to the point where there were only 3 bits left.
435        Fortunately, there was spare space in the data structure, and so I have
436        moved the internal flags into a new 16-bit field to free up more option
437        bits.
439    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
440        but did not set the internal JCHANGED flag - either of these is enough to
441        control the way the "get" function works - but the PCRE_INFO_JCHANGED
442        facility is supposed to tell if (?J) was ever used, so now (?J) at the
443        start sets both bits.
445    4.  Added options (at build time, compile time, exec time) to change \R from
446        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
448    5.  doc/pcresyntax.html was missing from the distribution.
450    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
451        compatibility, even though it is no longer used.
453    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
454        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
455        windows.h file is present (where different names are used). [This was
456        reversed later after testing - see 16 below.]
458    8.  Changed all #include <config.h> to #include "config.h". There were also
459        some further <pcre.h> cases that I changed to "pcre.h".
461    9.  When pcregrep was used with the --colour option, it missed the line ending
462        sequence off the lines that it output.
464    10. It was pointed out to me that arrays of string pointers cause lots of
465        relocations when a shared library is dynamically loaded. A technique of
466        using a single long string with a table of offsets can drastically reduce
467        these. I have refactored PCRE in four places to do this. The result is
468        dramatic:
470          Originally:                          290
471          After changing UCP table:            187
472          After changing error message table:   43
473          After changing table of "verbs"       36
474          After changing table of Posix names   22
476        Thanks to the folks working on Gregex for glib for this insight.
478    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
479        unicode-properties was also set.
481    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
483    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
484        checked only for CRLF.
486    14. Added casts to pcretest.c to avoid compiler warnings.
488    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
490    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
491        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
492        entirely. This removes changes made in 7 above.
494    17. The CMake files have been updated, and there is now more information about
495        building with CMake in the NON-UNIX-USE document.
498    Version 7.3 28-Aug-07
499    ---------------------
501     1. In the rejigging of the build system that eventually resulted in 7.1, the
502        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
503        brackets there is not right, since it causes compilers to look for an
504        installed pcre.h, not the version that is in the source that is being
505        compiled (which of course may be different). I have changed it back to:
507          #include "pcre.h"
509        I have a vague recollection that the change was concerned with compiling in
510        different directories, but in the new build system, that is taken care of
511        by the VPATH setting the Makefile.
513     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
514        when the subject happened to end in the byte 0x85 (e.g. if the last
515        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
516        characters but of course it shouldn't be taken as a newline when it is part
517        of another character. The bug was that, for an unlimited repeat of . in
518        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
519        characters when looking for a newline.
521     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
523     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
524        in debug output.
526     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
527        long printing in the pcrecpp unittest when running under MinGW.
529     6. ESC_K was left out of the EBCDIC table.
531     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
532        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
533        limit also applies to "virtual nesting" when a pattern is recursive, and in
534        this case 1000 isn't so big. I have been able to remove this limit at the
535        expense of backing off one optimization in certain circumstances. Normally,
536        when pcre_exec() would call its internal match() function recursively and
537        immediately return the result unconditionally, it uses a "tail recursion"
538        feature to save stack. However, when a subpattern that can match an empty
539        string has an unlimited repetition quantifier, it no longer makes this
540        optimization. That gives it a stack frame in which to save the data for
541        checking that an empty string has been matched. Previously this was taken
542        from the 1000-entry workspace that had been reserved. So now there is no
543        explicit limit, but more stack is used.
545     8. Applied Daniel's patches to solve problems with the import/export magic
546        syntax that is required for Windows, and which was going wrong for the
547        pcreposix and pcrecpp parts of the library. These were overlooked when this
548        problem was solved for the main library.
550     9. There were some crude static tests to avoid integer overflow when computing
551        the size of patterns that contain repeated groups with explicit upper
552        limits. As the maximum quantifier is 65535, the maximum group length was
553        set at 30,000 so that the product of these two numbers did not overflow a
554        32-bit integer. However, it turns out that people want to use groups that
555        are longer than 30,000 bytes (though not repeat them that many times).
556        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
557        made it possible to implement the integer overflow checks in a much more
558        dynamic way, which I have now done. The artificial limitation on group
559        length has been removed - we now have only the limit on the total length of
560        the compiled pattern, which depends on the LINK_SIZE setting.
562    10. Fixed a bug in the documentation for get/copy named substring when
563        duplicate names are permitted. If none of the named substrings are set, the
564        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
565        empty string.
567    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
568        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
569        because the ] is interpreted as the first data character and the
570        terminating ] is not found. PCRE has been made compatible with Perl in this
571        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
572        cause memory overwriting.
574    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
575        string has been matched (to stop an infinite loop). It was not recognizing
576        a conditional subpattern that could match an empty string if that
577        subpattern was within another subpattern. For example, it looped when
578        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
579        condition was not nested. This bug has been fixed.
581    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
582        past the start of the subject in the presence of bytes with the top bit
583        set, for example "\x8aBCD".
585    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
586        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
588    14. Optimized (?!) to (*FAIL).
590    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
591        This restricts code points to be within the range 0 to 0x10FFFF, excluding
592        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
593        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
594        does: it's just the validity check that is more restrictive.
596    16. Inserted checks for integer overflows during escape sequence (backslash)
597        processing, and also fixed erroneous offset values for syntax errors during
598        backslash processing.
600    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
601        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
603    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
604        caused an overrun.
606    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
607        something other than just ASCII characters) inside a group that had an
608        unlimited repeat caused a loop at compile time (while checking to see
609        whether the group could match an empty string).
611    20. Debugging a pattern containing \p or \P could cause a crash. For example,
612        [\P{Any}] did so. (Error in the code for printing property names.)
614    21. An orphan \E inside a character class could cause a crash.
616    22. A repeated capturing bracket such as (A)? could cause a wild memory
617        reference during compilation.
619    23. There are several functions in pcre_compile() that scan along a compiled
620        expression for various reasons (e.g. to see if it's fixed length for look
621        behind). There were bugs in these functions when a repeated \p or \P was
622        present in the pattern. These operators have additional parameters compared
623        with \d, etc, and these were not being taken into account when moving along
624        the compiled data. Specifically:
626        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
627            length.
629        (b) An item such as \pL+ within a repeated group could cause crashes or
630            loops.
632        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
633            "reference to non-existent subpattern" error.
635        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
637    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
638        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
640    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
642    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
643        character were causing crashes (broken optimization).
645    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
646        \p or \P) caused a compile-time loop.
648    28. More problems have arisen in unanchored patterns when CRLF is a valid line
649        break. For example, the unstudied pattern [\r\n]A does not match the string
650        "\r\nA" because change 7.0/46 below moves the current point on by two
651        characters after failing to match at the start. However, the pattern \nA
652        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
653        the same is true. There doesn't seem any very clean way out of this, but
654        what I have chosen to do makes the common cases work: PCRE now takes note
655        of whether there can be an explicit match for \r or \n anywhere in the
656        pattern, and if so, 7.0/46 no longer applies. As part of this change,
657        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
658        pattern has explicit CR or LF references.
660    29. Added (*CR) etc for changing newline setting at start of pattern.
663    Version 7.2 19-Jun-07
664  ---------------------  ---------------------
666   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 21  Version 7.2 01-May-07 Line 680  Version 7.2 01-May-07
680      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
681      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
682      in all cases.      in all cases.
684   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
686      (a) (?-n) (where n is a string of digits) is a relative subroutine or      (a) (?-n) (where n is a string of digits) is a relative subroutine or
687          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
689      (b) (?+n) is also a relative subroutine call; it refers to the nth next      (b) (?+n) is also a relative subroutine call; it refers to the nth next
690          to be opened parentheses.          to be opened parentheses.
692      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
693          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
695      (d) \K resets the start of the current match so that everything before      (d) \K resets the start of the current match so that everything before
696          is not part of it.          is not part of it.
698        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
700        (f) \g{name} is another synonym - part of Perl 5.10's unification of
701            reference syntax.
703        (g) (?| introduces a group in which the numbering of parentheses in each
704            alternative starts with the same number.
706        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
708     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
711     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
712        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
713        for detecting groups that can match an empty string.
715     9. A pattern with a very large number of alternatives (more than several
716        hundred) was running out of internal workspace during the pre-compile
717        phase, where pcre_compile() figures out how much memory will be needed. A
718        bit of new cunning has reduced the workspace needed for groups with
719        alternatives. The 1000-alternative test pattern now uses 12 bytes of
720        workspace instead of running out of the 4096 that are available.
722    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
724    11. Applied patch from Google to remove an optimization that didn't quite work.
725        The report of the bug said:
727          pcrecpp::RE("a*").FullMatch("aaa") matches, while
728          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
729          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
731    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
732        it matched the wrong number of bytes.
735  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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