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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 01-May-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    
36    Version 7.8 05-Sep-08
37    ---------------------
38    
39    1.  Replaced UCP searching code with optimized version as implemented for Ad
40        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
41        stage table and inline lookup instead of a function, giving speed ups of 2
42        to 5 times on some simple patterns that I tested. Permission was given to
43        distribute the MultiStage2.py script that generates the tables (it's not in
44        the tarball, but is in the Subversion repository).
45    
46    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
47        scripts.
48    
49    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
50        a group with a zero qualifier. The result of the study could be incorrect,
51        or the function might crash, depending on the pattern.
52    
53    4.  Caseless matching was not working for non-ASCII characters in back
54        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
55        It now works when Unicode Property Support is available.
56    
57    5.  In pcretest, an escape such as \x{de} in the data was always generating
58        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
59        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
60        truncation.
61    
62    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
63    
64    7.  Added two (int) casts to pcregrep when printing the difference of two
65        pointers, in case they are 64-bit values.
66    
67    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
68        test 2 if it fails.
69    
70    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
71        and a #define of that name to empty if it is not externally set. This is to
72        allow users of MSVC to set it if necessary.
73    
74    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
75        the convenience functions in the pcre_get.c source file.
76    
77    11. An option change at the start of a pattern that had top-level alternatives
78        could cause overwriting and/or a crash. This command provoked a crash in
79        some environments:
80    
81          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
82    
83        This potential security problem was recorded as CVE-2008-2371.
84    
85    12. For a pattern where the match had to start at the beginning or immediately
86        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
87        pcre_dfa_exec() could read past the end of the passed subject if there was
88        no match. To help with detecting such bugs (e.g. with valgrind), I modified
89        pcretest so that it places the subject at the end of its malloc-ed buffer.
90    
91    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
92        exec() might read past the end of the data buffer in UTF-8 mode.
93    
94    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
95        the data contained the byte 0x85 as part of a UTF-8 character within its
96        first line. This applied both to normal and DFA matching.
97    
98    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
99        /^[^d]*?$/8 failed to match "abc".
100    
101    16. Added a missing copyright notice to pcrecpp_internal.h.
102    
103    17. Make it more clear in the documentation that values returned from
104        pcre_exec() in ovector are byte offsets, not character counts.
105    
106    18. Tidied a few places to stop certain compilers from issuing warnings.
107    
108    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
109        supplied by Stefan Weber. I made a further small update for 7.8 because
110        there is a change of source arrangements: the pcre_searchfuncs.c module is
111        replaced by pcre_ucd.c.
112    
113    
114    Version 7.7 07-May-08
115    ---------------------
116    
117    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
118        a string to a long long, pretend we don't even have a long long." This is
119        done by checking for the strtoq, strtoll, and _strtoi64 functions.
120    
121    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
122        pre-7.6 versions, which defined a global no_arg variable instead of putting
123        it in the RE class. (See also #8 below.)
124    
125    3.  Remove a line of dead code, identified by coverity and reported by Nuno
126        Lopes.
127    
128    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
129    
130        (1) The include/exclude patterns were being applied to the whole pathnames
131            of files, instead of just to the final components.
132    
133        (2) If there was more than one level of directory, the subdirectories were
134            skipped unless they satisfied the include/exclude conditions. This is
135            inconsistent with GNU grep (and could even be seen as contrary to the
136            pcregrep specification - which I improved to make it absolutely clear).
137            The action now is always to scan all levels of directory, and just
138            apply the include/exclude patterns to regular files.
139    
140    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
141        --exclude_dir in the tests to avoid scanning .svn directories.
142    
143    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
144        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
145        doesn't support NULs in patterns.
146    
147    7.  Added some missing "const"s to declarations of static tables in
148        pcre_compile.c and pcre_dfa_exec.c.
149    
150    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
151        caused by fix #2  above. (Subsequently also a second patch to fix the
152        first patch. And a third patch - this was a messy problem.)
153    
154    9.  Applied Craig's patch to remove the use of push_back().
155    
156    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
157        matching function regexec().
158    
159    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
160        which, however, unlike Perl's \g{...}, are subroutine calls, not back
161        references. PCRE supports relative numbers with this syntax (I don't think
162        Oniguruma does).
163    
164    12. Previously, a group with a zero repeat such as (...){0} was completely
165        omitted from the compiled regex. However, this means that if the group
166        was called as a subroutine from elsewhere in the pattern, things went wrong
167        (an internal error was given). Such groups are now left in the compiled
168        pattern, with a new opcode that causes them to be skipped at execution
169        time.
170    
171    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
172        to the way PCRE behaves:
173    
174        (a) A lone ] character is dis-allowed (Perl treats it as data).
175    
176        (b) A back reference to an unmatched subpattern matches an empty string
177            (Perl fails the current match path).
178    
179        (c) A data ] in a character class must be notated as \] because if the
180            first data character in a class is ], it defines an empty class. (In
181            Perl it is not possible to have an empty class.) The empty class []
182            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
183            The negative empty class [^] matches any one character, independently
184            of the DOTALL setting.
185    
186    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
187        non-existent subpattern following a character class starting with ']' and
188        containing () gave an internal compiling error instead of "reference to
189        non-existent subpattern". Fortunately, when the pattern did exist, the
190        compiled code was correct. (When scanning forwards to check for the
191        existencd of the subpattern, it was treating the data ']' as terminating
192        the class, so got the count wrong. When actually compiling, the reference
193        was subsequently set up correctly.)
194    
195    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
196        it was being rejected as not supported by pcre_dfa_exec(), even though
197        other assertions are supported. I have made pcre_dfa_exec() support
198        (*FAIL).
199    
200    16. The implementation of 13c above involved the invention of a new opcode,
201        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
202        cannot be changed at match time, I realized I could make a small
203        improvement to matching performance by compiling OP_ALLANY instead of
204        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
205        on the OP_ANY path.
206    
207    17. Compiling pcretest on Windows with readline support failed without the
208        following two fixes: (1) Make the unistd.h include conditional on
209        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
210    
211    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
212        ncurses library to be included for pcretest when ReadLine support is
213        requested, but also to allow for it to be overridden. This patch came from
214        Daniel Bergström.
215    
216    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
217        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
218        any errors with the current Unicode tables. Thanks to Peter Kankowski for
219        spotting this.
220    
221    
222    Version 7.6 28-Jan-08
223    ---------------------
224    
225    1.  A character class containing a very large number of characters with
226        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
227        overflow.
228    
229    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
230        HAVE_LONG_LONG is not defined.
231    
232    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
233        bring them up to date and include new features. This patch includes:
234    
235        - Fixed PH's badly added libz and libbz2 support.
236        - Fixed a problem with static linking.
237        - Added pcredemo. [But later removed - see 7 below.]
238        - Fixed dftables problem and added an option.
239        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
240            HAVE_LONG_LONG.
241        - Added readline support for pcretest.
242        - Added an listing of the option settings after cmake has run.
243    
244    4.  A user submitted a patch to Makefile that makes it easy to create
245        "pcre.dll" under mingw when using Configure/Make. I added stuff to
246        Makefile.am that cause it to include this special target, without
247        affecting anything else. Note that the same mingw target plus all
248        the other distribution libraries and programs are now supported
249        when configuring with CMake (see 6 below) instead of with
250        Configure/Make.
251    
252    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
253        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
254        exported in the Windows port". It has not yet been confirmed that the patch
255        solves the problem, but it does no harm.
256    
257    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
258        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
259        with CMake, and also correct the comment about stack recursion.
260    
261    7.  Remove the automatic building of pcredemo from the ./configure system and
262        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
263        of a program that users should build themselves after PCRE is installed, so
264        building it automatically is not really right. What is more, it gave
265        trouble in some build environments.
266    
267    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
268    
269    
270    Version 7.5 10-Jan-08
271    ---------------------
272    
273    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
274        values in parens when parsing an RE using the C++ wrapper."
275    
276    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
277        Characters greater than 255 were excluded from the class instead of being
278        included.
279    
280    3.  The same bug as (2) above applied to negated POSIX classes such as
281        [:^space:].
282    
283    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
284        defined or documented. It seems to have been a typo for PCRE_STATIC, so
285        I have changed it.
286    
287    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
288        first named subpattern) and a construct such as (?&a) would reference the
289        first named subpattern whose name started with "a" (in other words, the
290        length check was missing). Both these problems are fixed. "Subpattern name
291        expected" is now given for (?&) (a zero-length name), and this patch also
292        makes it give the same error for \k'' (previously it complained that that
293        was a reference to a non-existent subpattern).
294    
295    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
296        this is right because (?- can be followed by option settings as well as by
297        digits. I have, however, made the messages clearer.
298    
299    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
300        than the number used in the conditional) now cause a compile-time error.
301        This is actually not compatible with Perl, which accepts such patterns, but
302        treats the conditional as always being FALSE (as PCRE used to), but it
303        seems to me that giving a diagnostic is better.
304    
305    8.  Change "alphameric" to the more common word "alphanumeric" in comments
306        and messages.
307    
308    9.  Fix two occurrences of "backslash" in comments that should have been
309        "backspace".
310    
311    10. Remove two redundant lines of code that can never be obeyed (their function
312        was moved elsewhere).
313    
314    11. The program that makes PCRE's Unicode character property table had a bug
315        which caused it to generate incorrect table entries for sequences of
316        characters that have the same character type, but are in different scripts.
317        It amalgamated them into a single range, with the script of the first of
318        them. In other words, some characters were in the wrong script. There were
319        thirteen such cases, affecting characters in the following ranges:
320    
321          U+002b0 - U+002c1
322          U+0060c - U+0060d
323          U+0061e - U+00612
324          U+0064b - U+0065e
325          U+0074d - U+0076d
326          U+01800 - U+01805
327          U+01d00 - U+01d77
328          U+01d9b - U+01dbf
329          U+0200b - U+0200f
330          U+030fc - U+030fe
331          U+03260 - U+0327f
332          U+0fb46 - U+0fbb1
333          U+10450 - U+1049d
334    
335    12. The -o option (show only the matching part of a line) for pcregrep was not
336        compatible with GNU grep in that, if there was more than one match in a
337        line, it showed only the first of them. It now behaves in the same way as
338        GNU grep.
339    
340    13. If the -o and -v options were combined for pcregrep, it printed a blank
341        line for every non-matching line. GNU grep prints nothing, and pcregrep now
342        does the same. The return code can be used to tell if there were any
343        non-matching lines.
344    
345    14. Added --file-offsets and --line-offsets to pcregrep.
346    
347    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
348        infinitely looping recursion. The bug was that positive lookaheads were not
349        being skipped when checking for a possible empty match (negative lookaheads
350        and both kinds of lookbehind were skipped).
351    
352    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
353        inclusion of <windows.h> to before rather than after the definition of
354        INVALID_FILE_ATTRIBUTES (patch from David Byron).
355    
356    17. Specifying a possessive quantifier with a specific limit for a Unicode
357        character property caused pcre_compile() to compile bad code, which led at
358        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
359        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
360        caused the error; without that there was no problem.
361    
362    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
363    
364    19. Added --enable-pcretest-libreadline.
365    
366    20. In pcrecpp.cc, the variable 'count' was incremented twice in
367        RE::GlobalReplace(). As a result, the number of replacements returned was
368        double what it should be. I removed one of the increments, but Craig sent a
369        later patch that removed the other one (the right fix) and added unit tests
370        that check the return values (which was not done before).
371    
372    21. Several CMake things:
373    
374        (1) Arranged that, when cmake is used on Unix, the libraries end up with
375            the names libpcre and libpcreposix, not just pcre and pcreposix.
376    
377        (2) The above change means that pcretest and pcregrep are now correctly
378            linked with the newly-built libraries, not previously installed ones.
379    
380        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
381    
382    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
383        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
384        UTF-8 newline character). The key issue is that the pattern starts .*;
385        this means that the match must be either at the beginning, or after a
386        newline. The bug was in the code for advancing after a failed match and
387        checking that the new position followed a newline. It was not taking
388        account of UTF-8 characters correctly.
389    
390    23. PCRE was behaving differently from Perl in the way it recognized POSIX
391        character classes. PCRE was not treating the sequence [:...:] as a
392        character class unless the ... were all letters. Perl, however, seems to
393        allow any characters between [: and :], though of course it rejects as
394        unknown any "names" that contain non-letters, because all the known class
395        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
396        for example, whereas PCRE did not - it did not recognize a POSIX character
397        class. This seemed a bit dangerous, so the code has been changed to be
398        closer to Perl. The behaviour is not identical to Perl, because PCRE will
399        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
400        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
401        Perl does, and where it didn't before.
402    
403    24. Rewrite so as to remove the single use of %n from pcregrep because in some
404        Windows environments %n is disabled by default.
405    
406    
407    Version 7.4 21-Sep-07
408    ---------------------
409    
410    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
411        means that a class such as [\s] counted as "explicit reference to CR or
412        LF". That isn't really right - the whole point of the change was to try to
413        help when there was an actual mention of one of the two characters. So now
414        the change happens only if \r or \n (or a literal CR or LF) character is
415        encountered.
416    
417    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
418        of both had grown to the point where there were only 3 bits left.
419        Fortunately, there was spare space in the data structure, and so I have
420        moved the internal flags into a new 16-bit field to free up more option
421        bits.
422    
423    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
424        but did not set the internal JCHANGED flag - either of these is enough to
425        control the way the "get" function works - but the PCRE_INFO_JCHANGED
426        facility is supposed to tell if (?J) was ever used, so now (?J) at the
427        start sets both bits.
428    
429    4.  Added options (at build time, compile time, exec time) to change \R from
430        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
431    
432    5.  doc/pcresyntax.html was missing from the distribution.
433    
434    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
435        compatibility, even though it is no longer used.
436    
437    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
438        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
439        windows.h file is present (where different names are used). [This was
440        reversed later after testing - see 16 below.]
441    
442    8.  Changed all #include <config.h> to #include "config.h". There were also
443        some further <pcre.h> cases that I changed to "pcre.h".
444    
445    9.  When pcregrep was used with the --colour option, it missed the line ending
446        sequence off the lines that it output.
447    
448    10. It was pointed out to me that arrays of string pointers cause lots of
449        relocations when a shared library is dynamically loaded. A technique of
450        using a single long string with a table of offsets can drastically reduce
451        these. I have refactored PCRE in four places to do this. The result is
452        dramatic:
453    
454          Originally:                          290
455          After changing UCP table:            187
456          After changing error message table:   43
457          After changing table of "verbs"       36
458          After changing table of Posix names   22
459    
460        Thanks to the folks working on Gregex for glib for this insight.
461    
462    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
463        unicode-properties was also set.
464    
465    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
466    
467    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
468        checked only for CRLF.
469    
470    14. Added casts to pcretest.c to avoid compiler warnings.
471    
472    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
473    
474    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
475        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
476        entirely. This removes changes made in 7 above.
477    
478    17. The CMake files have been updated, and there is now more information about
479        building with CMake in the NON-UNIX-USE document.
480    
481    
482    Version 7.3 28-Aug-07
483    ---------------------
484    
485     1. In the rejigging of the build system that eventually resulted in 7.1, the
486        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
487        brackets there is not right, since it causes compilers to look for an
488        installed pcre.h, not the version that is in the source that is being
489        compiled (which of course may be different). I have changed it back to:
490    
491          #include "pcre.h"
492    
493        I have a vague recollection that the change was concerned with compiling in
494        different directories, but in the new build system, that is taken care of
495        by the VPATH setting the Makefile.
496    
497     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
498        when the subject happened to end in the byte 0x85 (e.g. if the last
499        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
500        characters but of course it shouldn't be taken as a newline when it is part
501        of another character. The bug was that, for an unlimited repeat of . in
502        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
503        characters when looking for a newline.
504    
505     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
506    
507     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
508        in debug output.
509    
510     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
511        long printing in the pcrecpp unittest when running under MinGW.
512    
513     6. ESC_K was left out of the EBCDIC table.
514    
515     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
516        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
517        limit also applies to "virtual nesting" when a pattern is recursive, and in
518        this case 1000 isn't so big. I have been able to remove this limit at the
519        expense of backing off one optimization in certain circumstances. Normally,
520        when pcre_exec() would call its internal match() function recursively and
521        immediately return the result unconditionally, it uses a "tail recursion"
522        feature to save stack. However, when a subpattern that can match an empty
523        string has an unlimited repetition quantifier, it no longer makes this
524        optimization. That gives it a stack frame in which to save the data for
525        checking that an empty string has been matched. Previously this was taken
526        from the 1000-entry workspace that had been reserved. So now there is no
527        explicit limit, but more stack is used.
528    
529     8. Applied Daniel's patches to solve problems with the import/export magic
530        syntax that is required for Windows, and which was going wrong for the
531        pcreposix and pcrecpp parts of the library. These were overlooked when this
532        problem was solved for the main library.
533    
534     9. There were some crude static tests to avoid integer overflow when computing
535        the size of patterns that contain repeated groups with explicit upper
536        limits. As the maximum quantifier is 65535, the maximum group length was
537        set at 30,000 so that the product of these two numbers did not overflow a
538        32-bit integer. However, it turns out that people want to use groups that
539        are longer than 30,000 bytes (though not repeat them that many times).
540        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
541        made it possible to implement the integer overflow checks in a much more
542        dynamic way, which I have now done. The artificial limitation on group
543        length has been removed - we now have only the limit on the total length of
544        the compiled pattern, which depends on the LINK_SIZE setting.
545    
546    10. Fixed a bug in the documentation for get/copy named substring when
547        duplicate names are permitted. If none of the named substrings are set, the
548        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
549        empty string.
550    
551    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
552        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
553        because the ] is interpreted as the first data character and the
554        terminating ] is not found. PCRE has been made compatible with Perl in this
555        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
556        cause memory overwriting.
557    
558    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
559        string has been matched (to stop an infinite loop). It was not recognizing
560        a conditional subpattern that could match an empty string if that
561        subpattern was within another subpattern. For example, it looped when
562        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
563        condition was not nested. This bug has been fixed.
564    
565    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
566        past the start of the subject in the presence of bytes with the top bit
567        set, for example "\x8aBCD".
568    
569    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
570        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
571    
572    14. Optimized (?!) to (*FAIL).
573    
574    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
575        This restricts code points to be within the range 0 to 0x10FFFF, excluding
576        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
577        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
578        does: it's just the validity check that is more restrictive.
579    
580    16. Inserted checks for integer overflows during escape sequence (backslash)
581        processing, and also fixed erroneous offset values for syntax errors during
582        backslash processing.
583    
584    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
585        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
586    
587    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
588        caused an overrun.
589    
590    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
591        something other than just ASCII characters) inside a group that had an
592        unlimited repeat caused a loop at compile time (while checking to see
593        whether the group could match an empty string).
594    
595    20. Debugging a pattern containing \p or \P could cause a crash. For example,
596        [\P{Any}] did so. (Error in the code for printing property names.)
597    
598    21. An orphan \E inside a character class could cause a crash.
599    
600    22. A repeated capturing bracket such as (A)? could cause a wild memory
601        reference during compilation.
602    
603    23. There are several functions in pcre_compile() that scan along a compiled
604        expression for various reasons (e.g. to see if it's fixed length for look
605        behind). There were bugs in these functions when a repeated \p or \P was
606        present in the pattern. These operators have additional parameters compared
607        with \d, etc, and these were not being taken into account when moving along
608        the compiled data. Specifically:
609    
610        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
611            length.
612    
613        (b) An item such as \pL+ within a repeated group could cause crashes or
614            loops.
615    
616        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
617            "reference to non-existent subpattern" error.
618    
619        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
620    
621    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
622        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
623    
624    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
625    
626    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
627        character were causing crashes (broken optimization).
628    
629    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
630        \p or \P) caused a compile-time loop.
631    
632    28. More problems have arisen in unanchored patterns when CRLF is a valid line
633        break. For example, the unstudied pattern [\r\n]A does not match the string
634        "\r\nA" because change 7.0/46 below moves the current point on by two
635        characters after failing to match at the start. However, the pattern \nA
636        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
637        the same is true. There doesn't seem any very clean way out of this, but
638        what I have chosen to do makes the common cases work: PCRE now takes note
639        of whether there can be an explicit match for \r or \n anywhere in the
640        pattern, and if so, 7.0/46 no longer applies. As part of this change,
641        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
642        pattern has explicit CR or LF references.
643    
644    29. Added (*CR) etc for changing newline setting at start of pattern.
645    
646    
647    Version 7.2 19-Jun-07
648  ---------------------  ---------------------
649    
650   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 22  Version 7.2 01-May-07 Line 665  Version 7.2 01-May-07
665      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
666      in all cases.      in all cases.
667    
668     6. Added more features from the forthcoming Perl 5.10:
669    
670        (a) (?-n) (where n is a string of digits) is a relative subroutine or
671            recursion call. It refers to the nth most recently opened parentheses.
672    
673        (b) (?+n) is also a relative subroutine call; it refers to the nth next
674            to be opened parentheses.
675    
676        (c) Conditions that refer to capturing parentheses can be specified
677            relatively, for example, (?(-2)... or (?(+3)...
678    
679        (d) \K resets the start of the current match so that everything before
680            is not part of it.
681    
682        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
683    
684        (f) \g{name} is another synonym - part of Perl 5.10's unification of
685            reference syntax.
686    
687        (g) (?| introduces a group in which the numbering of parentheses in each
688            alternative starts with the same number.
689    
690        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
691    
692     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
693        PCRE_INFO_JCHANGED.
694    
695     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
696        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
697        for detecting groups that can match an empty string.
698    
699     9. A pattern with a very large number of alternatives (more than several
700        hundred) was running out of internal workspace during the pre-compile
701        phase, where pcre_compile() figures out how much memory will be needed. A
702        bit of new cunning has reduced the workspace needed for groups with
703        alternatives. The 1000-alternative test pattern now uses 12 bytes of
704        workspace instead of running out of the 4096 that are available.
705    
706    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
707    
708    11. Applied patch from Google to remove an optimization that didn't quite work.
709        The report of the bug said:
710    
711          pcrecpp::RE("a*").FullMatch("aaa") matches, while
712          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
713          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
714    
715    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
716        it matched the wrong number of bytes.
717    
718    
719  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
720  ---------------------  ---------------------

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