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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.
51    11. Unicode property support in character classes was not working for
52        characters (bytes) greater than 127 when not in UTF-8 mode.
54    12. Added the -M command line option to pcretest.
57    Version 7.8 05-Sep-08
58    ---------------------
60    1.  Replaced UCP searching code with optimized version as implemented for Ad
61        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
62        stage table and inline lookup instead of a function, giving speed ups of 2
63        to 5 times on some simple patterns that I tested. Permission was given to
64        distribute the MultiStage2.py script that generates the tables (it's not in
65        the tarball, but is in the Subversion repository).
67    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
68        scripts.
70    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
71        a group with a zero qualifier. The result of the study could be incorrect,
72        or the function might crash, depending on the pattern.
74    4.  Caseless matching was not working for non-ASCII characters in back
75        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
76        It now works when Unicode Property Support is available.
78    5.  In pcretest, an escape such as \x{de} in the data was always generating
79        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
80        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
81        truncation.
83    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
85    7.  Added two (int) casts to pcregrep when printing the difference of two
86        pointers, in case they are 64-bit values.
88    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
89        test 2 if it fails.
91    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
92        and a #define of that name to empty if it is not externally set. This is to
93        allow users of MSVC to set it if necessary.
95    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
96        the convenience functions in the pcre_get.c source file.
98    11. An option change at the start of a pattern that had top-level alternatives
99        could cause overwriting and/or a crash. This command provoked a crash in
100        some environments:
102          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
104        This potential security problem was recorded as CVE-2008-2371.
106    12. For a pattern where the match had to start at the beginning or immediately
107        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
108        pcre_dfa_exec() could read past the end of the passed subject if there was
109        no match. To help with detecting such bugs (e.g. with valgrind), I modified
110        pcretest so that it places the subject at the end of its malloc-ed buffer.
112    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
113        exec() might read past the end of the data buffer in UTF-8 mode.
115    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
116        the data contained the byte 0x85 as part of a UTF-8 character within its
117        first line. This applied both to normal and DFA matching.
119    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
120        /^[^d]*?$/8 failed to match "abc".
122    16. Added a missing copyright notice to pcrecpp_internal.h.
124    17. Make it more clear in the documentation that values returned from
125        pcre_exec() in ovector are byte offsets, not character counts.
127    18. Tidied a few places to stop certain compilers from issuing warnings.
129    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
130        supplied by Stefan Weber. I made a further small update for 7.8 because
131        there is a change of source arrangements: the pcre_searchfuncs.c module is
132        replaced by pcre_ucd.c.
135    Version 7.7 07-May-08
136    ---------------------
138    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
139        a string to a long long, pretend we don't even have a long long." This is
140        done by checking for the strtoq, strtoll, and _strtoi64 functions.
142    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
143        pre-7.6 versions, which defined a global no_arg variable instead of putting
144        it in the RE class. (See also #8 below.)
146    3.  Remove a line of dead code, identified by coverity and reported by Nuno
147        Lopes.
149    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
151        (1) The include/exclude patterns were being applied to the whole pathnames
152            of files, instead of just to the final components.
154        (2) If there was more than one level of directory, the subdirectories were
155            skipped unless they satisfied the include/exclude conditions. This is
156            inconsistent with GNU grep (and could even be seen as contrary to the
157            pcregrep specification - which I improved to make it absolutely clear).
158            The action now is always to scan all levels of directory, and just
159            apply the include/exclude patterns to regular files.
161    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
162        --exclude_dir in the tests to avoid scanning .svn directories.
164    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
165        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
166        doesn't support NULs in patterns.
168    7.  Added some missing "const"s to declarations of static tables in
169        pcre_compile.c and pcre_dfa_exec.c.
171    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
172        caused by fix #2  above. (Subsequently also a second patch to fix the
173        first patch. And a third patch - this was a messy problem.)
175    9.  Applied Craig's patch to remove the use of push_back().
177    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
178        matching function regexec().
180    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
181        which, however, unlike Perl's \g{...}, are subroutine calls, not back
182        references. PCRE supports relative numbers with this syntax (I don't think
183        Oniguruma does).
185    12. Previously, a group with a zero repeat such as (...){0} was completely
186        omitted from the compiled regex. However, this means that if the group
187        was called as a subroutine from elsewhere in the pattern, things went wrong
188        (an internal error was given). Such groups are now left in the compiled
189        pattern, with a new opcode that causes them to be skipped at execution
190        time.
192    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
193        to the way PCRE behaves:
195        (a) A lone ] character is dis-allowed (Perl treats it as data).
197        (b) A back reference to an unmatched subpattern matches an empty string
198            (Perl fails the current match path).
200        (c) A data ] in a character class must be notated as \] because if the
201            first data character in a class is ], it defines an empty class. (In
202            Perl it is not possible to have an empty class.) The empty class []
203            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
204            The negative empty class [^] matches any one character, independently
205            of the DOTALL setting.
207    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
208        non-existent subpattern following a character class starting with ']' and
209        containing () gave an internal compiling error instead of "reference to
210        non-existent subpattern". Fortunately, when the pattern did exist, the
211        compiled code was correct. (When scanning forwards to check for the
212        existencd of the subpattern, it was treating the data ']' as terminating
213        the class, so got the count wrong. When actually compiling, the reference
214        was subsequently set up correctly.)
216    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
217        it was being rejected as not supported by pcre_dfa_exec(), even though
218        other assertions are supported. I have made pcre_dfa_exec() support
219        (*FAIL).
221    16. The implementation of 13c above involved the invention of a new opcode,
222        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
223        cannot be changed at match time, I realized I could make a small
224        improvement to matching performance by compiling OP_ALLANY instead of
225        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
226        on the OP_ANY path.
228    17. Compiling pcretest on Windows with readline support failed without the
229        following two fixes: (1) Make the unistd.h include conditional on
230        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
232    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
233        ncurses library to be included for pcretest when ReadLine support is
234        requested, but also to allow for it to be overridden. This patch came from
235        Daniel Bergström.
237    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
238        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
239        any errors with the current Unicode tables. Thanks to Peter Kankowski for
240        spotting this.
243    Version 7.6 28-Jan-08
244    ---------------------
246    1.  A character class containing a very large number of characters with
247        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
248        overflow.
250    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
251        HAVE_LONG_LONG is not defined.
253    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
254        bring them up to date and include new features. This patch includes:
256        - Fixed PH's badly added libz and libbz2 support.
257        - Fixed a problem with static linking.
258        - Added pcredemo. [But later removed - see 7 below.]
259        - Fixed dftables problem and added an option.
260        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
261            HAVE_LONG_LONG.
262        - Added readline support for pcretest.
263        - Added an listing of the option settings after cmake has run.
265    4.  A user submitted a patch to Makefile that makes it easy to create
266        "pcre.dll" under mingw when using Configure/Make. I added stuff to
267        Makefile.am that cause it to include this special target, without
268        affecting anything else. Note that the same mingw target plus all
269        the other distribution libraries and programs are now supported
270        when configuring with CMake (see 6 below) instead of with
271        Configure/Make.
273    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
274        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
275        exported in the Windows port". It has not yet been confirmed that the patch
276        solves the problem, but it does no harm.
278    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
279        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
280        with CMake, and also correct the comment about stack recursion.
282    7.  Remove the automatic building of pcredemo from the ./configure system and
283        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
284        of a program that users should build themselves after PCRE is installed, so
285        building it automatically is not really right. What is more, it gave
286        trouble in some build environments.
288    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
291    Version 7.5 10-Jan-08
292    ---------------------
294    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
295        values in parens when parsing an RE using the C++ wrapper."
297    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
298        Characters greater than 255 were excluded from the class instead of being
299        included.
301    3.  The same bug as (2) above applied to negated POSIX classes such as
302        [:^space:].
304    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
305        defined or documented. It seems to have been a typo for PCRE_STATIC, so
306        I have changed it.
308    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
309        first named subpattern) and a construct such as (?&a) would reference the
310        first named subpattern whose name started with "a" (in other words, the
311        length check was missing). Both these problems are fixed. "Subpattern name
312        expected" is now given for (?&) (a zero-length name), and this patch also
313        makes it give the same error for \k'' (previously it complained that that
314        was a reference to a non-existent subpattern).
316    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
317        this is right because (?- can be followed by option settings as well as by
318        digits. I have, however, made the messages clearer.
320    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
321        than the number used in the conditional) now cause a compile-time error.
322        This is actually not compatible with Perl, which accepts such patterns, but
323        treats the conditional as always being FALSE (as PCRE used to), but it
324        seems to me that giving a diagnostic is better.
326    8.  Change "alphameric" to the more common word "alphanumeric" in comments
327        and messages.
329    9.  Fix two occurrences of "backslash" in comments that should have been
330        "backspace".
332    10. Remove two redundant lines of code that can never be obeyed (their function
333        was moved elsewhere).
335    11. The program that makes PCRE's Unicode character property table had a bug
336        which caused it to generate incorrect table entries for sequences of
337        characters that have the same character type, but are in different scripts.
338        It amalgamated them into a single range, with the script of the first of
339        them. In other words, some characters were in the wrong script. There were
340        thirteen such cases, affecting characters in the following ranges:
342          U+002b0 - U+002c1
343          U+0060c - U+0060d
344          U+0061e - U+00612
345          U+0064b - U+0065e
346          U+0074d - U+0076d
347          U+01800 - U+01805
348          U+01d00 - U+01d77
349          U+01d9b - U+01dbf
350          U+0200b - U+0200f
351          U+030fc - U+030fe
352          U+03260 - U+0327f
353          U+0fb46 - U+0fbb1
354          U+10450 - U+1049d
356    12. The -o option (show only the matching part of a line) for pcregrep was not
357        compatible with GNU grep in that, if there was more than one match in a
358        line, it showed only the first of them. It now behaves in the same way as
359        GNU grep.
361    13. If the -o and -v options were combined for pcregrep, it printed a blank
362        line for every non-matching line. GNU grep prints nothing, and pcregrep now
363        does the same. The return code can be used to tell if there were any
364        non-matching lines.
366    14. Added --file-offsets and --line-offsets to pcregrep.
368    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
369        infinitely looping recursion. The bug was that positive lookaheads were not
370        being skipped when checking for a possible empty match (negative lookaheads
371        and both kinds of lookbehind were skipped).
373    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
374        inclusion of <windows.h> to before rather than after the definition of
375        INVALID_FILE_ATTRIBUTES (patch from David Byron).
377    17. Specifying a possessive quantifier with a specific limit for a Unicode
378        character property caused pcre_compile() to compile bad code, which led at
379        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
380        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
381        caused the error; without that there was no problem.
383    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
385    19. Added --enable-pcretest-libreadline.
387    20. In pcrecpp.cc, the variable 'count' was incremented twice in
388        RE::GlobalReplace(). As a result, the number of replacements returned was
389        double what it should be. I removed one of the increments, but Craig sent a
390        later patch that removed the other one (the right fix) and added unit tests
391        that check the return values (which was not done before).
393    21. Several CMake things:
395        (1) Arranged that, when cmake is used on Unix, the libraries end up with
396            the names libpcre and libpcreposix, not just pcre and pcreposix.
398        (2) The above change means that pcretest and pcregrep are now correctly
399            linked with the newly-built libraries, not previously installed ones.
403    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
404        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
405        UTF-8 newline character). The key issue is that the pattern starts .*;
406        this means that the match must be either at the beginning, or after a
407        newline. The bug was in the code for advancing after a failed match and
408        checking that the new position followed a newline. It was not taking
409        account of UTF-8 characters correctly.
411    23. PCRE was behaving differently from Perl in the way it recognized POSIX
412        character classes. PCRE was not treating the sequence [:...:] as a
413        character class unless the ... were all letters. Perl, however, seems to
414        allow any characters between [: and :], though of course it rejects as
415        unknown any "names" that contain non-letters, because all the known class
416        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
417        for example, whereas PCRE did not - it did not recognize a POSIX character
418        class. This seemed a bit dangerous, so the code has been changed to be
419        closer to Perl. The behaviour is not identical to Perl, because PCRE will
420        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
421        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
422        Perl does, and where it didn't before.
424    24. Rewrite so as to remove the single use of %n from pcregrep because in some
425        Windows environments %n is disabled by default.
428    Version 7.4 21-Sep-07
429    ---------------------
431    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
432        means that a class such as [\s] counted as "explicit reference to CR or
433        LF". That isn't really right - the whole point of the change was to try to
434        help when there was an actual mention of one of the two characters. So now
435        the change happens only if \r or \n (or a literal CR or LF) character is
436        encountered.
438    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
439        of both had grown to the point where there were only 3 bits left.
440        Fortunately, there was spare space in the data structure, and so I have
441        moved the internal flags into a new 16-bit field to free up more option
442        bits.
444    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
445        but did not set the internal JCHANGED flag - either of these is enough to
446        control the way the "get" function works - but the PCRE_INFO_JCHANGED
447        facility is supposed to tell if (?J) was ever used, so now (?J) at the
448        start sets both bits.
450    4.  Added options (at build time, compile time, exec time) to change \R from
451        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
453    5.  doc/pcresyntax.html was missing from the distribution.
455    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
456        compatibility, even though it is no longer used.
458    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
459        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
460        windows.h file is present (where different names are used). [This was
461        reversed later after testing - see 16 below.]
463    8.  Changed all #include <config.h> to #include "config.h". There were also
464        some further <pcre.h> cases that I changed to "pcre.h".
466    9.  When pcregrep was used with the --colour option, it missed the line ending
467        sequence off the lines that it output.
469    10. It was pointed out to me that arrays of string pointers cause lots of
470        relocations when a shared library is dynamically loaded. A technique of
471        using a single long string with a table of offsets can drastically reduce
472        these. I have refactored PCRE in four places to do this. The result is
473        dramatic:
475          Originally:                          290
476          After changing UCP table:            187
477          After changing error message table:   43
478          After changing table of "verbs"       36
479          After changing table of Posix names   22
481        Thanks to the folks working on Gregex for glib for this insight.
483    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
484        unicode-properties was also set.
486    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
488    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
489        checked only for CRLF.
491    14. Added casts to pcretest.c to avoid compiler warnings.
493    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
495    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
496        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
497        entirely. This removes changes made in 7 above.
499    17. The CMake files have been updated, and there is now more information about
500        building with CMake in the NON-UNIX-USE document.
503    Version 7.3 28-Aug-07
504    ---------------------
506     1. In the rejigging of the build system that eventually resulted in 7.1, the
507        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
508        brackets there is not right, since it causes compilers to look for an
509        installed pcre.h, not the version that is in the source that is being
510        compiled (which of course may be different). I have changed it back to:
512          #include "pcre.h"
514        I have a vague recollection that the change was concerned with compiling in
515        different directories, but in the new build system, that is taken care of
516        by the VPATH setting the Makefile.
518     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
519        when the subject happened to end in the byte 0x85 (e.g. if the last
520        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
521        characters but of course it shouldn't be taken as a newline when it is part
522        of another character. The bug was that, for an unlimited repeat of . in
523        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
524        characters when looking for a newline.
526     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
528     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
529        in debug output.
531     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
532        long printing in the pcrecpp unittest when running under MinGW.
534     6. ESC_K was left out of the EBCDIC table.
536     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
537        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
538        limit also applies to "virtual nesting" when a pattern is recursive, and in
539        this case 1000 isn't so big. I have been able to remove this limit at the
540        expense of backing off one optimization in certain circumstances. Normally,
541        when pcre_exec() would call its internal match() function recursively and
542        immediately return the result unconditionally, it uses a "tail recursion"
543        feature to save stack. However, when a subpattern that can match an empty
544        string has an unlimited repetition quantifier, it no longer makes this
545        optimization. That gives it a stack frame in which to save the data for
546        checking that an empty string has been matched. Previously this was taken
547        from the 1000-entry workspace that had been reserved. So now there is no
548        explicit limit, but more stack is used.
550     8. Applied Daniel's patches to solve problems with the import/export magic
551        syntax that is required for Windows, and which was going wrong for the
552        pcreposix and pcrecpp parts of the library. These were overlooked when this
553        problem was solved for the main library.
555     9. There were some crude static tests to avoid integer overflow when computing
556        the size of patterns that contain repeated groups with explicit upper
557        limits. As the maximum quantifier is 65535, the maximum group length was
558        set at 30,000 so that the product of these two numbers did not overflow a
559        32-bit integer. However, it turns out that people want to use groups that
560        are longer than 30,000 bytes (though not repeat them that many times).
561        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
562        made it possible to implement the integer overflow checks in a much more
563        dynamic way, which I have now done. The artificial limitation on group
564        length has been removed - we now have only the limit on the total length of
565        the compiled pattern, which depends on the LINK_SIZE setting.
567    10. Fixed a bug in the documentation for get/copy named substring when
568        duplicate names are permitted. If none of the named substrings are set, the
569        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
570        empty string.
572    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
573        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
574        because the ] is interpreted as the first data character and the
575        terminating ] is not found. PCRE has been made compatible with Perl in this
576        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
577        cause memory overwriting.
579    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
580        string has been matched (to stop an infinite loop). It was not recognizing
581        a conditional subpattern that could match an empty string if that
582        subpattern was within another subpattern. For example, it looped when
583        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
584        condition was not nested. This bug has been fixed.
586    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
587        past the start of the subject in the presence of bytes with the top bit
588        set, for example "\x8aBCD".
590    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
591        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
593    14. Optimized (?!) to (*FAIL).
595    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
596        This restricts code points to be within the range 0 to 0x10FFFF, excluding
597        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
598        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
599        does: it's just the validity check that is more restrictive.
601    16. Inserted checks for integer overflows during escape sequence (backslash)
602        processing, and also fixed erroneous offset values for syntax errors during
603        backslash processing.
605    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
606        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
608    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
609        caused an overrun.
611    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
612        something other than just ASCII characters) inside a group that had an
613        unlimited repeat caused a loop at compile time (while checking to see
614        whether the group could match an empty string).
616    20. Debugging a pattern containing \p or \P could cause a crash. For example,
617        [\P{Any}] did so. (Error in the code for printing property names.)
619    21. An orphan \E inside a character class could cause a crash.
621    22. A repeated capturing bracket such as (A)? could cause a wild memory
622        reference during compilation.
624    23. There are several functions in pcre_compile() that scan along a compiled
625        expression for various reasons (e.g. to see if it's fixed length for look
626        behind). There were bugs in these functions when a repeated \p or \P was
627        present in the pattern. These operators have additional parameters compared
628        with \d, etc, and these were not being taken into account when moving along
629        the compiled data. Specifically:
631        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
632            length.
634        (b) An item such as \pL+ within a repeated group could cause crashes or
635            loops.
637        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
638            "reference to non-existent subpattern" error.
640        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
642    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
643        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
645    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
647    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
648        character were causing crashes (broken optimization).
650    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
651        \p or \P) caused a compile-time loop.
653    28. More problems have arisen in unanchored patterns when CRLF is a valid line
654        break. For example, the unstudied pattern [\r\n]A does not match the string
655        "\r\nA" because change 7.0/46 below moves the current point on by two
656        characters after failing to match at the start. However, the pattern \nA
657        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
658        the same is true. There doesn't seem any very clean way out of this, but
659        what I have chosen to do makes the common cases work: PCRE now takes note
660        of whether there can be an explicit match for \r or \n anywhere in the
661        pattern, and if so, 7.0/46 no longer applies. As part of this change,
662        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
663        pattern has explicit CR or LF references.
665    29. Added (*CR) etc for changing newline setting at start of pattern.
668    Version 7.2 19-Jun-07
669  ---------------------  ---------------------
671   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 685  Version 7.2 01-May-07
685      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
686      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
687      in all cases.      in all cases.
689   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
691      (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
692          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
694      (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
695          to be opened parentheses.          to be opened parentheses.
697      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
698          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
700      (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
701          is not part of it.          is not part of it.
703   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and      (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
705        (f) \g{name} is another synonym - part of Perl 5.10's unification of
706            reference syntax.
708        (g) (?| introduces a group in which the numbering of parentheses in each
709            alternative starts with the same number.
711        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
713     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
716     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
717        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
718        for detecting groups that can match an empty string.
720     9. A pattern with a very large number of alternatives (more than several
721        hundred) was running out of internal workspace during the pre-compile
722        phase, where pcre_compile() figures out how much memory will be needed. A
723        bit of new cunning has reduced the workspace needed for groups with
724        alternatives. The 1000-alternative test pattern now uses 12 bytes of
725        workspace instead of running out of the 4096 that are available.
727    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
729    11. Applied patch from Google to remove an optimization that didn't quite work.
730        The report of the bug said:
732          pcrecpp::RE("a*").FullMatch("aaa") matches, while
733          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
734          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
736    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
737        it matched the wrong number of bytes.
740  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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