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revision 65 by nigel, Sat Feb 24 21:40:08 2007 UTC revision 381 by ph10, Tue Mar 3 16:08:23 2009 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.9 xx-xxx-09
5    ---------------------
6    
7    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
8        (pcretest), all targets were linked against these libraries. This included
9        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
10        libraries. This caused unwanted dependencies to be created. This problem
11        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
12        pcretest is linked with readline.
13    
14    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
15        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
16        moved outside it again, because FALSE and TRUE are already defined in AIX,
17        but BOOL is not.
18    
19    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
20        PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.
21    
22    4.  The pcregrep documentation said spaces were inserted as well as colons (or
23        hyphens) following file names and line numbers when outputting matching
24        lines. This is not true; no spaces are inserted. I have also clarified the
25        wording for the --colour (or --color) option.
26    
27    5.  In pcregrep, when --colour was used with -o, the list of matching strings
28        was not coloured; this is different to GNU grep, so I have changed it to be
29        the same.
30    
31    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
32        each matching line was coloured. Now it goes on to look for further matches
33        of any of the test patterns, which is the same behaviour as GNU grep.
34    
35    7.  A pattern that could match an empty string could cause pcregrep to loop; it
36        doesn't make sense to accept an empty string match in pcregrep, so I have
37        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38        seems to be how GNU grep behaves.
39    
40    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.
44    
45    9.  If auto-callout was enabled in a pattern with a conditional group, PCRE
46        could crash during matching.
47    
48    
49    Version 7.8 05-Sep-08
50    ---------------------
51    
52    1.  Replaced UCP searching code with optimized version as implemented for Ad
53        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
54        stage table and inline lookup instead of a function, giving speed ups of 2
55        to 5 times on some simple patterns that I tested. Permission was given to
56        distribute the MultiStage2.py script that generates the tables (it's not in
57        the tarball, but is in the Subversion repository).
58    
59    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
60        scripts.
61    
62    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
63        a group with a zero qualifier. The result of the study could be incorrect,
64        or the function might crash, depending on the pattern.
65    
66    4.  Caseless matching was not working for non-ASCII characters in back
67        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
68        It now works when Unicode Property Support is available.
69    
70    5.  In pcretest, an escape such as \x{de} in the data was always generating
71        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
72        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
73        truncation.
74    
75    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
76    
77    7.  Added two (int) casts to pcregrep when printing the difference of two
78        pointers, in case they are 64-bit values.
79    
80    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
81        test 2 if it fails.
82    
83    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
84        and a #define of that name to empty if it is not externally set. This is to
85        allow users of MSVC to set it if necessary.
86    
87    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
88        the convenience functions in the pcre_get.c source file.
89    
90    11. An option change at the start of a pattern that had top-level alternatives
91        could cause overwriting and/or a crash. This command provoked a crash in
92        some environments:
93    
94          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
95    
96        This potential security problem was recorded as CVE-2008-2371.
97    
98    12. For a pattern where the match had to start at the beginning or immediately
99        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
100        pcre_dfa_exec() could read past the end of the passed subject if there was
101        no match. To help with detecting such bugs (e.g. with valgrind), I modified
102        pcretest so that it places the subject at the end of its malloc-ed buffer.
103    
104    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
105        exec() might read past the end of the data buffer in UTF-8 mode.
106    
107    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
108        the data contained the byte 0x85 as part of a UTF-8 character within its
109        first line. This applied both to normal and DFA matching.
110    
111    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
112        /^[^d]*?$/8 failed to match "abc".
113    
114    16. Added a missing copyright notice to pcrecpp_internal.h.
115    
116    17. Make it more clear in the documentation that values returned from
117        pcre_exec() in ovector are byte offsets, not character counts.
118    
119    18. Tidied a few places to stop certain compilers from issuing warnings.
120    
121    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
122        supplied by Stefan Weber. I made a further small update for 7.8 because
123        there is a change of source arrangements: the pcre_searchfuncs.c module is
124        replaced by pcre_ucd.c.
125    
126    
127    Version 7.7 07-May-08
128    ---------------------
129    
130    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
131        a string to a long long, pretend we don't even have a long long." This is
132        done by checking for the strtoq, strtoll, and _strtoi64 functions.
133    
134    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
135        pre-7.6 versions, which defined a global no_arg variable instead of putting
136        it in the RE class. (See also #8 below.)
137    
138    3.  Remove a line of dead code, identified by coverity and reported by Nuno
139        Lopes.
140    
141    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
142    
143        (1) The include/exclude patterns were being applied to the whole pathnames
144            of files, instead of just to the final components.
145    
146        (2) If there was more than one level of directory, the subdirectories were
147            skipped unless they satisfied the include/exclude conditions. This is
148            inconsistent with GNU grep (and could even be seen as contrary to the
149            pcregrep specification - which I improved to make it absolutely clear).
150            The action now is always to scan all levels of directory, and just
151            apply the include/exclude patterns to regular files.
152    
153    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
154        --exclude_dir in the tests to avoid scanning .svn directories.
155    
156    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
157        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
158        doesn't support NULs in patterns.
159    
160    7.  Added some missing "const"s to declarations of static tables in
161        pcre_compile.c and pcre_dfa_exec.c.
162    
163    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
164        caused by fix #2  above. (Subsequently also a second patch to fix the
165        first patch. And a third patch - this was a messy problem.)
166    
167    9.  Applied Craig's patch to remove the use of push_back().
168    
169    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
170        matching function regexec().
171    
172    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
173        which, however, unlike Perl's \g{...}, are subroutine calls, not back
174        references. PCRE supports relative numbers with this syntax (I don't think
175        Oniguruma does).
176    
177    12. Previously, a group with a zero repeat such as (...){0} was completely
178        omitted from the compiled regex. However, this means that if the group
179        was called as a subroutine from elsewhere in the pattern, things went wrong
180        (an internal error was given). Such groups are now left in the compiled
181        pattern, with a new opcode that causes them to be skipped at execution
182        time.
183    
184    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
185        to the way PCRE behaves:
186    
187        (a) A lone ] character is dis-allowed (Perl treats it as data).
188    
189        (b) A back reference to an unmatched subpattern matches an empty string
190            (Perl fails the current match path).
191    
192        (c) A data ] in a character class must be notated as \] because if the
193            first data character in a class is ], it defines an empty class. (In
194            Perl it is not possible to have an empty class.) The empty class []
195            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
196            The negative empty class [^] matches any one character, independently
197            of the DOTALL setting.
198    
199    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
200        non-existent subpattern following a character class starting with ']' and
201        containing () gave an internal compiling error instead of "reference to
202        non-existent subpattern". Fortunately, when the pattern did exist, the
203        compiled code was correct. (When scanning forwards to check for the
204        existencd of the subpattern, it was treating the data ']' as terminating
205        the class, so got the count wrong. When actually compiling, the reference
206        was subsequently set up correctly.)
207    
208    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
209        it was being rejected as not supported by pcre_dfa_exec(), even though
210        other assertions are supported. I have made pcre_dfa_exec() support
211        (*FAIL).
212    
213    16. The implementation of 13c above involved the invention of a new opcode,
214        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
215        cannot be changed at match time, I realized I could make a small
216        improvement to matching performance by compiling OP_ALLANY instead of
217        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
218        on the OP_ANY path.
219    
220    17. Compiling pcretest on Windows with readline support failed without the
221        following two fixes: (1) Make the unistd.h include conditional on
222        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
223    
224    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
225        ncurses library to be included for pcretest when ReadLine support is
226        requested, but also to allow for it to be overridden. This patch came from
227        Daniel Bergström.
228    
229    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
230        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
231        any errors with the current Unicode tables. Thanks to Peter Kankowski for
232        spotting this.
233    
234    
235    Version 7.6 28-Jan-08
236    ---------------------
237    
238    1.  A character class containing a very large number of characters with
239        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
240        overflow.
241    
242    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
243        HAVE_LONG_LONG is not defined.
244    
245    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
246        bring them up to date and include new features. This patch includes:
247    
248        - Fixed PH's badly added libz and libbz2 support.
249        - Fixed a problem with static linking.
250        - Added pcredemo. [But later removed - see 7 below.]
251        - Fixed dftables problem and added an option.
252        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
253            HAVE_LONG_LONG.
254        - Added readline support for pcretest.
255        - Added an listing of the option settings after cmake has run.
256    
257    4.  A user submitted a patch to Makefile that makes it easy to create
258        "pcre.dll" under mingw when using Configure/Make. I added stuff to
259        Makefile.am that cause it to include this special target, without
260        affecting anything else. Note that the same mingw target plus all
261        the other distribution libraries and programs are now supported
262        when configuring with CMake (see 6 below) instead of with
263        Configure/Make.
264    
265    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
266        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
267        exported in the Windows port". It has not yet been confirmed that the patch
268        solves the problem, but it does no harm.
269    
270    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
271        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
272        with CMake, and also correct the comment about stack recursion.
273    
274    7.  Remove the automatic building of pcredemo from the ./configure system and
275        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
276        of a program that users should build themselves after PCRE is installed, so
277        building it automatically is not really right. What is more, it gave
278        trouble in some build environments.
279    
280    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
281    
282    
283    Version 7.5 10-Jan-08
284    ---------------------
285    
286    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
287        values in parens when parsing an RE using the C++ wrapper."
288    
289    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
290        Characters greater than 255 were excluded from the class instead of being
291        included.
292    
293    3.  The same bug as (2) above applied to negated POSIX classes such as
294        [:^space:].
295    
296    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
297        defined or documented. It seems to have been a typo for PCRE_STATIC, so
298        I have changed it.
299    
300    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
301        first named subpattern) and a construct such as (?&a) would reference the
302        first named subpattern whose name started with "a" (in other words, the
303        length check was missing). Both these problems are fixed. "Subpattern name
304        expected" is now given for (?&) (a zero-length name), and this patch also
305        makes it give the same error for \k'' (previously it complained that that
306        was a reference to a non-existent subpattern).
307    
308    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
309        this is right because (?- can be followed by option settings as well as by
310        digits. I have, however, made the messages clearer.
311    
312    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
313        than the number used in the conditional) now cause a compile-time error.
314        This is actually not compatible with Perl, which accepts such patterns, but
315        treats the conditional as always being FALSE (as PCRE used to), but it
316        seems to me that giving a diagnostic is better.
317    
318    8.  Change "alphameric" to the more common word "alphanumeric" in comments
319        and messages.
320    
321    9.  Fix two occurrences of "backslash" in comments that should have been
322        "backspace".
323    
324    10. Remove two redundant lines of code that can never be obeyed (their function
325        was moved elsewhere).
326    
327    11. The program that makes PCRE's Unicode character property table had a bug
328        which caused it to generate incorrect table entries for sequences of
329        characters that have the same character type, but are in different scripts.
330        It amalgamated them into a single range, with the script of the first of
331        them. In other words, some characters were in the wrong script. There were
332        thirteen such cases, affecting characters in the following ranges:
333    
334          U+002b0 - U+002c1
335          U+0060c - U+0060d
336          U+0061e - U+00612
337          U+0064b - U+0065e
338          U+0074d - U+0076d
339          U+01800 - U+01805
340          U+01d00 - U+01d77
341          U+01d9b - U+01dbf
342          U+0200b - U+0200f
343          U+030fc - U+030fe
344          U+03260 - U+0327f
345          U+0fb46 - U+0fbb1
346          U+10450 - U+1049d
347    
348    12. The -o option (show only the matching part of a line) for pcregrep was not
349        compatible with GNU grep in that, if there was more than one match in a
350        line, it showed only the first of them. It now behaves in the same way as
351        GNU grep.
352    
353    13. If the -o and -v options were combined for pcregrep, it printed a blank
354        line for every non-matching line. GNU grep prints nothing, and pcregrep now
355        does the same. The return code can be used to tell if there were any
356        non-matching lines.
357    
358    14. Added --file-offsets and --line-offsets to pcregrep.
359    
360    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
361        infinitely looping recursion. The bug was that positive lookaheads were not
362        being skipped when checking for a possible empty match (negative lookaheads
363        and both kinds of lookbehind were skipped).
364    
365    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
366        inclusion of <windows.h> to before rather than after the definition of
367        INVALID_FILE_ATTRIBUTES (patch from David Byron).
368    
369    17. Specifying a possessive quantifier with a specific limit for a Unicode
370        character property caused pcre_compile() to compile bad code, which led at
371        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
372        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
373        caused the error; without that there was no problem.
374    
375    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
376    
377    19. Added --enable-pcretest-libreadline.
378    
379    20. In pcrecpp.cc, the variable 'count' was incremented twice in
380        RE::GlobalReplace(). As a result, the number of replacements returned was
381        double what it should be. I removed one of the increments, but Craig sent a
382        later patch that removed the other one (the right fix) and added unit tests
383        that check the return values (which was not done before).
384    
385    21. Several CMake things:
386    
387        (1) Arranged that, when cmake is used on Unix, the libraries end up with
388            the names libpcre and libpcreposix, not just pcre and pcreposix.
389    
390        (2) The above change means that pcretest and pcregrep are now correctly
391            linked with the newly-built libraries, not previously installed ones.
392    
393        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
394    
395    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
396        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
397        UTF-8 newline character). The key issue is that the pattern starts .*;
398        this means that the match must be either at the beginning, or after a
399        newline. The bug was in the code for advancing after a failed match and
400        checking that the new position followed a newline. It was not taking
401        account of UTF-8 characters correctly.
402    
403    23. PCRE was behaving differently from Perl in the way it recognized POSIX
404        character classes. PCRE was not treating the sequence [:...:] as a
405        character class unless the ... were all letters. Perl, however, seems to
406        allow any characters between [: and :], though of course it rejects as
407        unknown any "names" that contain non-letters, because all the known class
408        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
409        for example, whereas PCRE did not - it did not recognize a POSIX character
410        class. This seemed a bit dangerous, so the code has been changed to be
411        closer to Perl. The behaviour is not identical to Perl, because PCRE will
412        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
413        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
414        Perl does, and where it didn't before.
415    
416    24. Rewrite so as to remove the single use of %n from pcregrep because in some
417        Windows environments %n is disabled by default.
418    
419    
420    Version 7.4 21-Sep-07
421    ---------------------
422    
423    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
424        means that a class such as [\s] counted as "explicit reference to CR or
425        LF". That isn't really right - the whole point of the change was to try to
426        help when there was an actual mention of one of the two characters. So now
427        the change happens only if \r or \n (or a literal CR or LF) character is
428        encountered.
429    
430    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
431        of both had grown to the point where there were only 3 bits left.
432        Fortunately, there was spare space in the data structure, and so I have
433        moved the internal flags into a new 16-bit field to free up more option
434        bits.
435    
436    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
437        but did not set the internal JCHANGED flag - either of these is enough to
438        control the way the "get" function works - but the PCRE_INFO_JCHANGED
439        facility is supposed to tell if (?J) was ever used, so now (?J) at the
440        start sets both bits.
441    
442    4.  Added options (at build time, compile time, exec time) to change \R from
443        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
444    
445    5.  doc/pcresyntax.html was missing from the distribution.
446    
447    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
448        compatibility, even though it is no longer used.
449    
450    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
451        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
452        windows.h file is present (where different names are used). [This was
453        reversed later after testing - see 16 below.]
454    
455    8.  Changed all #include <config.h> to #include "config.h". There were also
456        some further <pcre.h> cases that I changed to "pcre.h".
457    
458    9.  When pcregrep was used with the --colour option, it missed the line ending
459        sequence off the lines that it output.
460    
461    10. It was pointed out to me that arrays of string pointers cause lots of
462        relocations when a shared library is dynamically loaded. A technique of
463        using a single long string with a table of offsets can drastically reduce
464        these. I have refactored PCRE in four places to do this. The result is
465        dramatic:
466    
467          Originally:                          290
468          After changing UCP table:            187
469          After changing error message table:   43
470          After changing table of "verbs"       36
471          After changing table of Posix names   22
472    
473        Thanks to the folks working on Gregex for glib for this insight.
474    
475    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
476        unicode-properties was also set.
477    
478    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
479    
480    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
481        checked only for CRLF.
482    
483    14. Added casts to pcretest.c to avoid compiler warnings.
484    
485    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
486    
487    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
488        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
489        entirely. This removes changes made in 7 above.
490    
491    17. The CMake files have been updated, and there is now more information about
492        building with CMake in the NON-UNIX-USE document.
493    
494    
495    Version 7.3 28-Aug-07
496    ---------------------
497    
498     1. In the rejigging of the build system that eventually resulted in 7.1, the
499        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
500        brackets there is not right, since it causes compilers to look for an
501        installed pcre.h, not the version that is in the source that is being
502        compiled (which of course may be different). I have changed it back to:
503    
504          #include "pcre.h"
505    
506        I have a vague recollection that the change was concerned with compiling in
507        different directories, but in the new build system, that is taken care of
508        by the VPATH setting the Makefile.
509    
510     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
511        when the subject happened to end in the byte 0x85 (e.g. if the last
512        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
513        characters but of course it shouldn't be taken as a newline when it is part
514        of another character. The bug was that, for an unlimited repeat of . in
515        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
516        characters when looking for a newline.
517    
518     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
519    
520     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
521        in debug output.
522    
523     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
524        long printing in the pcrecpp unittest when running under MinGW.
525    
526     6. ESC_K was left out of the EBCDIC table.
527    
528     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
529        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
530        limit also applies to "virtual nesting" when a pattern is recursive, and in
531        this case 1000 isn't so big. I have been able to remove this limit at the
532        expense of backing off one optimization in certain circumstances. Normally,
533        when pcre_exec() would call its internal match() function recursively and
534        immediately return the result unconditionally, it uses a "tail recursion"
535        feature to save stack. However, when a subpattern that can match an empty
536        string has an unlimited repetition quantifier, it no longer makes this
537        optimization. That gives it a stack frame in which to save the data for
538        checking that an empty string has been matched. Previously this was taken
539        from the 1000-entry workspace that had been reserved. So now there is no
540        explicit limit, but more stack is used.
541    
542     8. Applied Daniel's patches to solve problems with the import/export magic
543        syntax that is required for Windows, and which was going wrong for the
544        pcreposix and pcrecpp parts of the library. These were overlooked when this
545        problem was solved for the main library.
546    
547     9. There were some crude static tests to avoid integer overflow when computing
548        the size of patterns that contain repeated groups with explicit upper
549        limits. As the maximum quantifier is 65535, the maximum group length was
550        set at 30,000 so that the product of these two numbers did not overflow a
551        32-bit integer. However, it turns out that people want to use groups that
552        are longer than 30,000 bytes (though not repeat them that many times).
553        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
554        made it possible to implement the integer overflow checks in a much more
555        dynamic way, which I have now done. The artificial limitation on group
556        length has been removed - we now have only the limit on the total length of
557        the compiled pattern, which depends on the LINK_SIZE setting.
558    
559    10. Fixed a bug in the documentation for get/copy named substring when
560        duplicate names are permitted. If none of the named substrings are set, the
561        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
562        empty string.
563    
564    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
565        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
566        because the ] is interpreted as the first data character and the
567        terminating ] is not found. PCRE has been made compatible with Perl in this
568        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
569        cause memory overwriting.
570    
571    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
572        string has been matched (to stop an infinite loop). It was not recognizing
573        a conditional subpattern that could match an empty string if that
574        subpattern was within another subpattern. For example, it looped when
575        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
576        condition was not nested. This bug has been fixed.
577    
578    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
579        past the start of the subject in the presence of bytes with the top bit
580        set, for example "\x8aBCD".
581    
582    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
583        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
584    
585    14. Optimized (?!) to (*FAIL).
586    
587    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
588        This restricts code points to be within the range 0 to 0x10FFFF, excluding
589        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
590        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
591        does: it's just the validity check that is more restrictive.
592    
593    16. Inserted checks for integer overflows during escape sequence (backslash)
594        processing, and also fixed erroneous offset values for syntax errors during
595        backslash processing.
596    
597    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
598        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
599    
600    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
601        caused an overrun.
602    
603    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
604        something other than just ASCII characters) inside a group that had an
605        unlimited repeat caused a loop at compile time (while checking to see
606        whether the group could match an empty string).
607    
608    20. Debugging a pattern containing \p or \P could cause a crash. For example,
609        [\P{Any}] did so. (Error in the code for printing property names.)
610    
611    21. An orphan \E inside a character class could cause a crash.
612    
613    22. A repeated capturing bracket such as (A)? could cause a wild memory
614        reference during compilation.
615    
616    23. There are several functions in pcre_compile() that scan along a compiled
617        expression for various reasons (e.g. to see if it's fixed length for look
618        behind). There were bugs in these functions when a repeated \p or \P was
619        present in the pattern. These operators have additional parameters compared
620        with \d, etc, and these were not being taken into account when moving along
621        the compiled data. Specifically:
622    
623        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
624            length.
625    
626        (b) An item such as \pL+ within a repeated group could cause crashes or
627            loops.
628    
629        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
630            "reference to non-existent subpattern" error.
631    
632        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
633    
634    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
635        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
636    
637    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
638    
639    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
640        character were causing crashes (broken optimization).
641    
642    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
643        \p or \P) caused a compile-time loop.
644    
645    28. More problems have arisen in unanchored patterns when CRLF is a valid line
646        break. For example, the unstudied pattern [\r\n]A does not match the string
647        "\r\nA" because change 7.0/46 below moves the current point on by two
648        characters after failing to match at the start. However, the pattern \nA
649        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
650        the same is true. There doesn't seem any very clean way out of this, but
651        what I have chosen to do makes the common cases work: PCRE now takes note
652        of whether there can be an explicit match for \r or \n anywhere in the
653        pattern, and if so, 7.0/46 no longer applies. As part of this change,
654        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
655        pattern has explicit CR or LF references.
656    
657    29. Added (*CR) etc for changing newline setting at start of pattern.
658    
659    
660    Version 7.2 19-Jun-07
661    ---------------------
662    
663     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
664        which is apparently normally available under Windows.
665    
666     2. Re-jig the pcregrep tests with different newline settings in an attempt
667        to make them independent of the local environment's newline setting.
668    
669     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
670    
671     4. Some of the "internals" tests were previously cut out when the link size
672        was not 2, because the output contained actual offsets. The recent new
673        "Z" feature of pcretest means that these can be cut out, making the tests
674        usable with all link sizes.
675    
676     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
677        stack recursion. This gives a massive performance boost under BSD, but just
678        a small improvement under Linux. However, it saves one field in the frame
679        in all cases.
680    
681     6. Added more features from the forthcoming Perl 5.10:
682    
683        (a) (?-n) (where n is a string of digits) is a relative subroutine or
684            recursion call. It refers to the nth most recently opened parentheses.
685    
686        (b) (?+n) is also a relative subroutine call; it refers to the nth next
687            to be opened parentheses.
688    
689        (c) Conditions that refer to capturing parentheses can be specified
690            relatively, for example, (?(-2)... or (?(+3)...
691    
692        (d) \K resets the start of the current match so that everything before
693            is not part of it.
694    
695        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
696    
697        (f) \g{name} is another synonym - part of Perl 5.10's unification of
698            reference syntax.
699    
700        (g) (?| introduces a group in which the numbering of parentheses in each
701            alternative starts with the same number.
702    
703        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
704    
705     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
706        PCRE_INFO_JCHANGED.
707    
708     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
709        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
710        for detecting groups that can match an empty string.
711    
712     9. A pattern with a very large number of alternatives (more than several
713        hundred) was running out of internal workspace during the pre-compile
714        phase, where pcre_compile() figures out how much memory will be needed. A
715        bit of new cunning has reduced the workspace needed for groups with
716        alternatives. The 1000-alternative test pattern now uses 12 bytes of
717        workspace instead of running out of the 4096 that are available.
718    
719    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
720    
721    11. Applied patch from Google to remove an optimization that didn't quite work.
722        The report of the bug said:
723    
724          pcrecpp::RE("a*").FullMatch("aaa") matches, while
725          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
726          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
727    
728    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
729        it matched the wrong number of bytes.
730    
731    
732    Version 7.1 24-Apr-07
733    ---------------------
734    
735     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
736        that is more "standard", making use of automake and other Autotools. There
737        is some re-arrangement of the files and adjustment of comments consequent
738        on this.
739    
740     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
741        for recursive directory scanning broke on some systems because the files
742        are not scanned in any specific order and on different systems the order
743        was different. A call to "sort" has been inserted into RunGrepTest for the
744        approprate test as a short-term fix. In the longer term there may be an
745        alternative.
746    
747     3. I had an email from Eric Raymond about problems translating some of PCRE's
748        man pages to HTML (despite the fact that I distribute HTML pages, some
749        people do their own conversions for various reasons). The problems
750        concerned the use of low-level troff macros .br and .in. I have therefore
751        removed all such uses from the man pages (some were redundant, some could
752        be replaced by .nf/.fi pairs). The 132html script that I use to generate
753        HTML has been updated to handle .nf/.fi and to complain if it encounters
754        .br or .in.
755    
756     4. Updated comments in configure.ac that get placed in config.h.in and also
757        arranged for config.h to be included in the distribution, with the name
758        config.h.generic, for the benefit of those who have to compile without
759        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
760    
761     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
762        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
763        makevp.bat for the current PCRE, using the additional files
764        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
765    
766     6. A Windows user reported a minor discrepancy with test 2, which turned out
767        to be caused by a trailing space on an input line that had got lost in his
768        copy. The trailing space was an accident, so I've just removed it.
769    
770     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
771        that is needed.
772    
773     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
774        as "const" (a) because they are and (b) because it helps the PHP
775        maintainers who have recently made a script to detect big data structures
776        in the php code that should be moved to the .rodata section. I remembered
777        to update Builducptable as well, so it won't revert if ucptable.h is ever
778        re-created.
779    
780     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
781        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
782        order to be able to cut out the UTF-8 tables in the latter when UTF-8
783        support is not required. This saves 1.5-2K of code, which is important in
784        some applications.
785    
786        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
787        so as not to refer to the tables, even though these functions will never be
788        called when UTF-8 support is disabled. Otherwise there are problems with a
789        shared library.
790    
791    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
792    
793        (a) It was defining its arguments as char * instead of void *.
794    
795        (b) It was assuming that all moves were upwards in memory; this was true
796            a long time ago when I wrote it, but is no longer the case.
797    
798        The emulated memove() is provided for those environments that have neither
799        memmove() nor bcopy(). I didn't think anyone used it these days, but that
800        is clearly not the case, as these two bugs were recently reported.
801    
802    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
803        and Detrail to create the HTML documentation, the .txt form of the man
804        pages, and it removes trailing spaces from listed files. It also creates
805        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
806        case, it wraps all the #defines with #ifndefs. This script should be run
807        before "make dist".
808    
809    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
810        with Unicode property support.
811    
812        (a) For a maximizing quantifier, if the two different cases of the
813            character were of different lengths in their UTF-8 codings (there are
814            some cases like this - I found 11), and the matching function had to
815            back up over a mixture of the two cases, it incorrectly assumed they
816            were both the same length.
817    
818        (b) When PCRE was configured to use the heap rather than the stack for
819            recursion during matching, it was not correctly preserving the data for
820            the other case of a UTF-8 character when checking ahead for a match
821            while processing a minimizing repeat. If the check also involved
822            matching a wide character, but failed, corruption could cause an
823            erroneous result when trying to check for a repeat of the original
824            character.
825    
826    13. Some tidying changes to the testing mechanism:
827    
828        (a) The RunTest script now detects the internal link size and whether there
829            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
830            values substituted by "configure". (The RunGrepTest script already did
831            this for UTF-8.) The configure.ac script no longer substitutes the
832            relevant variables.
833    
834        (b) The debugging options /B and /D in pcretest show the compiled bytecode
835            with length and offset values. This means that the output is different
836            for different internal link sizes. Test 2 is skipped for link sizes
837            other than 2 because of this, bypassing the problem. Unfortunately,
838            there was also a test in test 3 (the locale tests) that used /B and
839            failed for link sizes other than 2. Rather than cut the whole test out,
840            I have added a new /Z option to pcretest that replaces the length and
841            offset values with spaces. This is now used to make test 3 independent
842            of link size. (Test 2 will be tidied up later.)
843    
844    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
845        segmentation fault instead of returning the appropriate error message.
846    
847    15. In multiline mode when the newline sequence was set to "any", the pattern
848        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
849        This doesn't seem right; it now treats the CRLF combination as the line
850        ending, and so does not match in that case. It's only a pattern such as ^$
851        that would hit this one: something like ^ABC$ would have failed after \r
852        and then tried again after \r\n.
853    
854    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
855        in an attempt to make files that differ only in their line terminators
856        compare equal. This works on Linux.
857    
858    17. Under certain error circumstances pcregrep might try to free random memory
859        as it exited. This is now fixed, thanks to valgrind.
860    
861    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
862        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
863        was because its rules for how to advance for /g after matching an empty
864        string at the end of a line did not allow for this case. They now check for
865        it specially.
866    
867    20. pcretest is supposed to handle patterns and data of any length, by
868        extending its buffers when necessary. It was getting this wrong when the
869        buffer for a data line had to be extended.
870    
871    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
872        CRLF as a newline sequence.
873    
874    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
875        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
876        I have nevertheless tidied it up.
877    
878    23. Added some casts to kill warnings from HP-UX ia64 compiler.
879    
880    24. Added a man page for pcre-config.
881    
882    
883    Version 7.0 19-Dec-06
884    ---------------------
885    
886     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
887        moving to gcc 4.1.1.
888    
889     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
890        sys/time.h, which is documented as needed for this function. It doesn't
891        seem to matter on Linux, but it showed up on some releases of OS X.
892    
893     3. It seems that there are systems where bytes whose values are greater than
894        127 match isprint() in the "C" locale. The "C" locale should be the
895        default when a C program starts up. In most systems, only ASCII printing
896        characters match isprint(). This difference caused the output from pcretest
897        to vary, making some of the tests fail. I have changed pcretest so that:
898    
899        (a) When it is outputting text in the compiled version of a pattern, bytes
900            other than 32-126 are always shown as hex escapes.
901    
902        (b) When it is outputting text that is a matched part of a subject string,
903            it does the same, unless a different locale has been set for the match
904            (using the /L modifier). In this case, it uses isprint() to decide.
905    
906     4. Fixed a major bug that caused incorrect computation of the amount of memory
907        required for a compiled pattern when options that changed within the
908        pattern affected the logic of the preliminary scan that determines the
909        length. The relevant options are -x, and -i in UTF-8 mode. The result was
910        that the computed length was too small. The symptoms of this bug were
911        either the PCRE error "internal error: code overflow" from pcre_compile(),
912        or a glibc crash with a message such as "pcretest: free(): invalid next
913        size (fast)". Examples of patterns that provoked this bug (shown in
914        pcretest format) are:
915    
916          /(?-x: )/x
917          /(?x)(?-x: \s*#\s*)/
918          /((?i)[\x{c0}])/8
919          /(?i:[\x{c0}])/8
920    
921        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
922        is now done differently.
923    
924     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
925        wrapper classes; (b) implement a new function in the C++ scanner that is
926        more efficient than the old way of doing things because it avoids levels of
927        recursion in the regex matching; (c) add a paragraph to the documentation
928        for the FullMatch() function.
929    
930     6. The escape sequence \n was being treated as whatever was defined as
931        "newline". Not only was this contrary to the documentation, which states
932        that \n is character 10 (hex 0A), but it also went horribly wrong when
933        "newline" was defined as CRLF. This has been fixed.
934    
935     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
936        was being set to -1 for the "end of line" case (supposedly a value that no
937        character can have). Though this value is never used (the check for end of
938        line is "zero bytes in current character"), it caused compiler complaints.
939        I've changed it to 0xffffffff.
940    
941     8. In pcre_version.c, the version string was being built by a sequence of
942        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
943        string (as it is for production releases) called a macro with an empty
944        argument. The C standard says the result of this is undefined. The gcc
945        compiler treats it as an empty string (which was what was wanted) but it is
946        reported that Visual C gives an error. The source has been hacked around to
947        avoid this problem.
948    
949     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
950        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
951        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
952        of them did).
953    
954    10. Originally, pcretest opened its input and output without "b"; then I was
955        told that "b" was needed in some environments, so it was added for release
956        5.0 to both the input and output. (It makes no difference on Unix-like
957        systems.) Later I was told that it is wrong for the input on Windows. I've
958        now abstracted the modes into two macros, to make it easier to fiddle with
959        them, and removed "b" from the input mode under Windows.
960    
961    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
962    
963    12. Added -help and --help to pcretest as an official way of being reminded
964        of the options.
965    
966    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
967        and pcrecpp.cc because they annoy compilers at high warning levels.
968    
969    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
970    
971    15. Fixed an occurrence of == in configure.ac that should have been = (shell
972        scripts are not C programs :-) and which was not noticed because it works
973        on Linux.
974    
975    16. pcretest is supposed to handle any length of pattern and data line (as one
976        line or as a continued sequence of lines) by extending its input buffer if
977        necessary. This feature was broken for very long pattern lines, leading to
978        a string of junk being passed to pcre_compile() if the pattern was longer
979        than about 50K.
980    
981    17. I have done a major re-factoring of the way pcre_compile() computes the
982        amount of memory needed for a compiled pattern. Previously, there was code
983        that made a preliminary scan of the pattern in order to do this. That was
984        OK when PCRE was new, but as the facilities have expanded, it has become
985        harder and harder to keep it in step with the real compile phase, and there
986        have been a number of bugs (see for example, 4 above). I have now found a
987        cunning way of running the real compile function in a "fake" mode that
988        enables it to compute how much memory it would need, while actually only
989        ever using a few hundred bytes of working memory and without too many
990        tests of the mode. This should make future maintenance and development
991        easier. A side effect of this work is that the limit of 200 on the nesting
992        depth of parentheses has been removed (though this was never a serious
993        limitation, I suspect). However, there is a downside: pcre_compile() now
994        runs more slowly than before (30% or more, depending on the pattern). I
995        hope this isn't a big issue. There is no effect on runtime performance.
996    
997    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
998        newline (only possible for the last line of a file) and it was a
999        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1000    
1001    19. Added additional timing features to pcretest. (1) The -tm option now times
1002        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1003        separate command line item, by a number that specifies the number of
1004        repeats to use when timing. The default is 50000; this gives better
1005        precision, but takes uncomfortably long for very large patterns.
1006    
1007    20. Extended pcre_study() to be more clever in cases where a branch of a
1008        subpattern has no definite first character. For example, (a*|b*)[cd] would
1009        previously give no result from pcre_study(). Now it recognizes that the
1010        first character must be a, b, c, or d.
1011    
1012    21. There was an incorrect error "recursive call could loop indefinitely" if
1013        a subpattern (or the entire pattern) that was being tested for matching an
1014        empty string contained only one non-empty item after a nested subpattern.
1015        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1016        incorrectly, because the \d was being skipped in the check.
1017    
1018    22. The pcretest program now has a new pattern option /B and a command line
1019        option -b, which is equivalent to adding /B to every pattern. This causes
1020        it to show the compiled bytecode, without the additional information that
1021        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1022        is the same as /B/I).
1023    
1024    23. A new optimization is now able automatically to treat some sequences such
1025        as a*b as a*+b. More specifically, if something simple (such as a character
1026        or a simple class like \d) has an unlimited quantifier, and is followed by
1027        something that cannot possibly match the quantified thing, the quantifier
1028        is automatically "possessified".
1029    
1030    24. A recursive reference to a subpattern whose number was greater than 39
1031        went wrong under certain circumstances in UTF-8 mode. This bug could also
1032        have affected the operation of pcre_study().
1033    
1034    25. Realized that a little bit of performance could be had by replacing
1035        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1036    
1037    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1038    
1039    27. Possessive quantifiers such as a++ were previously implemented by turning
1040        them into atomic groups such as ($>a+). Now they have their own opcodes,
1041        which improves performance. This includes the automatically created ones
1042        from 23 above.
1043    
1044    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1045        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1046        the first matched character to be a colon. This applied both to named and
1047        numbered groups.
1048    
1049    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1050    
1051    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1052        building PCRE on Windows easier, so I have included it in the distribution.
1053    
1054    31. There is now a check in pcretest against a ridiculously large number being
1055        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1056        loop, the loop is abandoned.
1057    
1058    32. Forward references to subpatterns in conditions such as (?(2)...) where
1059        subpattern 2 is defined later cause pcre_compile() to search forwards in
1060        the pattern for the relevant set of parentheses. This search went wrong
1061        when there were unescaped parentheses in a character class, parentheses
1062        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1063    
1064    33. "Subroutine" calls and backreferences were previously restricted to
1065        referencing subpatterns earlier in the regex. This restriction has now
1066        been removed.
1067    
1068    34. Added a number of extra features that are going to be in Perl 5.10. On the
1069        whole, these are just syntactic alternatives for features that PCRE had
1070        previously implemented using the Python syntax or my own invention. The
1071        other formats are all retained for compatibility.
1072    
1073        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1074            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1075            also .NET compatible.
1076    
1077        (b) A recursion or subroutine call to a named group can now be defined as
1078            (?&name) as well as (?P>name).
1079    
1080        (c) A backreference to a named group can now be defined as \k<name> or
1081            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1082            5.10, are also .NET compatible.
1083    
1084        (d) A conditional reference to a named group can now use the syntax
1085            (?(<name>) or (?('name') as well as (?(name).
1086    
1087        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1088            groups (named and numbered) that are never evaluated inline, but can be
1089            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1090            is always false. There may be only one alternative in such a group.
1091    
1092        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1093            as the simple (?(R). The condition is true only if the most recent
1094            recursion is that of the given number or name. It does not search out
1095            through the entire recursion stack.
1096    
1097        (g) The escape \gN or \g{N} has been added, where N is a positive or
1098            negative number, specifying an absolute or relative reference.
1099    
1100    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1101        some "unreachable code" warnings.
1102    
1103    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1104        things, this adds five new scripts.
1105    
1106    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1107        There were also incompatibilities regarding the handling of \Q..\E inside
1108        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1109        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1110    
1111    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1112        matches an empty string, and forcibly breaks the loop. There were bugs in
1113        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1114        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1115        separate and independent bugs (that affected different cases) have been
1116        fixed.
1117    
1118    39. Refactored the code to abolish the use of different opcodes for small
1119        capturing bracket numbers. This is a tidy that I avoided doing when I
1120        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1121        The new approach is not only tidier, it makes it possible to reduce the
1122        memory needed to fix the previous bug (38).
1123    
1124    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1125        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1126        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1127        mode.
1128    
1129    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1130        report.
1131    
1132    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1133        copy construction and assignment in the C++ wrapper.
1134    
1135    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1136        couple of bugs that could have given wrong results in the "--newline=crlf"
1137        case.
1138    
1139    44. Added a number of casts and did some reorganization of signed/unsigned int
1140        variables following suggestions from Dair Grant. Also renamed the variable
1141        "this" as "item" because it is a C++ keyword.
1142    
1143    45. Arranged for dftables to add
1144    
1145          #include "pcre_internal.h"
1146    
1147        to pcre_chartables.c because without it, gcc 4.x may remove the array
1148        definition from the final binary if PCRE is built into a static library and
1149        dead code stripping is activated.
1150    
1151    46. For an unanchored pattern, if a match attempt fails at the start of a
1152        newline sequence, and the newline setting is CRLF or ANY, and the next two
1153        characters are CRLF, advance by two characters instead of one.
1154    
1155    
1156    Version 6.7 04-Jul-06
1157    ---------------------
1158    
1159     1. In order to handle tests when input lines are enormously long, pcretest has
1160        been re-factored so that it automatically extends its buffers when
1161        necessary. The code is crude, but this _is_ just a test program. The
1162        default size has been increased from 32K to 50K.
1163    
1164     2. The code in pcre_study() was using the value of the re argument before
1165        testing it for NULL. (Of course, in any sensible call of the function, it
1166        won't be NULL.)
1167    
1168     3. The memmove() emulation function in pcre_internal.h, which is used on
1169        systems that lack both memmove() and bcopy() - that is, hardly ever -
1170        was missing a "static" storage class specifier.
1171    
1172     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1173        containing an extended class (one that cannot be represented by a bitmap
1174        because it contains high-valued characters or Unicode property items, e.g.
1175        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1176        pattern, but PCRE should not loop if you do not (it no longer does).
1177        [Detail: two cases were found: (a) a repeated subpattern containing an
1178        extended class; (b) a recursive reference to a subpattern that followed a
1179        previous extended class. It wasn't skipping over the extended class
1180        correctly when UTF-8 mode was not set.]
1181    
1182     5. A negated single-character class was not being recognized as fixed-length
1183        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1184        compile error "lookbehind assertion is not fixed length".
1185    
1186     6. The RunPerlTest auxiliary script was showing an unexpected difference
1187        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1188        write a Perl script that can interpret lines of an input file either as
1189        byte characters or as UTF-8, which is what "perltest" was being required to
1190        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1191        can't do is switch easily at run time between having the "use utf8;" pragma
1192        or not. In the end, I fudged it by using the RunPerlTest script to insert
1193        "use utf8;" explicitly for the UTF-8 tests.
1194    
1195     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1196        the end of the subject string, contrary to the documentation and to what
1197        Perl does. This was true of both matching functions. Now it matches only at
1198        the start of the subject and immediately after *internal* newlines.
1199    
1200     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1201        a pointer to an int instead of a pointer to an unsigned long int. This
1202        caused problems on 64-bit systems.
1203    
1204     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1205        instance of the 'standard' template library not being so standard".
1206    
1207    10. There was no check on the number of named subpatterns nor the maximum
1208        length of a subpattern name. The product of these values is used to compute
1209        the size of the memory block for a compiled pattern. By supplying a very
1210        long subpattern name and a large number of named subpatterns, the size
1211        computation could be caused to overflow. This is now prevented by limiting
1212        the length of names to 32 characters, and the number of named subpatterns
1213        to 10,000.
1214    
1215    11. Subpatterns that are repeated with specific counts have to be replicated in
1216        the compiled pattern. The size of memory for this was computed from the
1217        length of the subpattern and the repeat count. The latter is limited to
1218        65535, but there was no limit on the former, meaning that integer overflow
1219        could in principle occur. The compiled length of a repeated subpattern is
1220        now limited to 30,000 bytes in order to prevent this.
1221    
1222    12. Added the optional facility to have named substrings with the same name.
1223    
1224    13. Added the ability to use a named substring as a condition, using the
1225        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1226        are numbers (not recommended). Forward references are permitted.
1227    
1228    14. Added forward references in named backreferences (if you see what I mean).
1229    
1230    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1231        pattern could run off the end of the subject. For example, the pattern
1232        "(?s)(.{1,5})"8 did this with the subject "ab".
1233    
1234    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1235        PCRE_CASELESS was set when matching characters that were quantified with ?
1236        or *.
1237    
1238    17. A character class other than a single negated character that had a minimum
1239        but no maximum quantifier - for example [ab]{6,} - was not handled
1240        correctly by pce_dfa_exec(). It would match only one character.
1241    
1242    18. A valid (though odd) pattern that looked like a POSIX character
1243        class but used an invalid character after [ (for example [[,abc,]]) caused
1244        pcre_compile() to give the error "Failed: internal error: code overflow" or
1245        in some cases to crash with a glibc free() error. This could even happen if
1246        the pattern terminated after [[ but there just happened to be a sequence of
1247        letters, a binary zero, and a closing ] in the memory that followed.
1248    
1249    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1250        over the years. Originally (before any Unicode support), just the bottom 8
1251        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1252        output from "man perlunicode" includes this:
1253    
1254          The regular expression compiler produces polymorphic opcodes.  That
1255          is, the pattern adapts to the data and automatically switches to
1256          the Unicode character scheme when presented with Unicode data--or
1257          instead uses a traditional byte scheme when presented with byte
1258          data.
1259    
1260        Sadly, a wide octal escape does not cause a switch, and in a string with
1261        no other multibyte characters, these octal escapes are treated as before.
1262        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1263        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1264        Unicode string.
1265    
1266        I have not perpetrated such confusion in PCRE. Up till now, it took just
1267        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1268        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1269        translate to the appropriate multibyte character.
1270    
1271    29. Applied some refactoring to reduce the number of warnings from Microsoft
1272        and Borland compilers. This has included removing the fudge introduced
1273        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1274        a warning about an unused variable.
1275    
1276    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1277        characters since release 4.0, because Perl (from release 5.004) does not.
1278        [Or at least, is documented not to: some releases seem to be in conflict
1279        with the documentation.] However, when a pattern was studied with
1280        pcre_study() and all its branches started with \s, PCRE still included VT
1281        as a possible starting character. Of course, this did no harm; it just
1282        caused an unnecessary match attempt.
1283    
1284    22. Removed a now-redundant internal flag bit that recorded the fact that case
1285        dependency changed within the pattern. This was once needed for "required
1286        byte" processing, but is no longer used. This recovers a now-scarce options
1287        bit. Also moved the least significant internal flag bit to the most-
1288        significant bit of the word, which was not previously used (hangover from
1289        the days when it was an int rather than a uint) to free up another bit for
1290        the future.
1291    
1292    23. Added support for CRLF line endings as well as CR and LF. As well as the
1293        default being selectable at build time, it can now be changed at runtime
1294        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1295        specify that it is scanning data with non-default line endings.
1296    
1297    24. Changed the definition of CXXLINK to make it agree with the definition of
1298        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1299    
1300    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1301        recursions. This makes a big different to stack usage for some patterns.
1302    
1303    26. If a subpattern containing a named recursion or subroutine reference such
1304        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1305        the space required for the compiled pattern went wrong and gave too small a
1306        value. Depending on the environment, this could lead to "Failed: internal
1307        error: code overflow at offset 49" or "glibc detected double free or
1308        corruption" errors.
1309    
1310    27. Applied patches from Google (a) to support the new newline modes and (b) to
1311        advance over multibyte UTF-8 characters in GlobalReplace.
1312    
1313    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1314        difference for some implementation of PCRE in some Windows version.
1315    
1316    29. Added some extra testing facilities to pcretest:
1317    
1318        \q<number>   in a data line sets the "match limit" value
1319        \Q<number>   in a data line sets the "match recursion limt" value
1320        -S <number>  sets the stack size, where <number> is in megabytes
1321    
1322        The -S option isn't available for Windows.
1323    
1324    
1325    Version 6.6 06-Feb-06
1326    ---------------------
1327    
1328     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1329        in pcreposix.h. I have copied the definition from pcre.h.
1330    
1331     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1332        because pcre.h is no longer a built file.
1333    
1334     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1335        not normally included in the compiled code.
1336    
1337    
1338    Version 6.5 01-Feb-06
1339    ---------------------
1340    
1341     1. When using the partial match feature with pcre_dfa_exec(), it was not
1342        anchoring the second and subsequent partial matches at the new starting
1343        point. This could lead to incorrect results. For example, with the pattern
1344        /1234/, partially matching against "123" and then "a4" gave a match.
1345    
1346     2. Changes to pcregrep:
1347    
1348        (a) All non-match returns from pcre_exec() were being treated as failures
1349            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1350            error message is output. Some extra information is given for the
1351            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1352            probably the only errors that are likely to be caused by users (by
1353            specifying a regex that has nested indefinite repeats, for instance).
1354            If there are more than 20 of these errors, pcregrep is abandoned.
1355    
1356        (b) A binary zero was treated as data while matching, but terminated the
1357            output line if it was written out. This has been fixed: binary zeroes
1358            are now no different to any other data bytes.
1359    
1360        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1361            used to set a locale for matching. The --locale=xxxx long option has
1362            been added (no short equivalent) to specify a locale explicitly on the
1363            pcregrep command, overriding the environment variables.
1364    
1365        (d) When -B was used with -n, some line numbers in the output were one less
1366            than they should have been.
1367    
1368        (e) Added the -o (--only-matching) option.
1369    
1370        (f) If -A or -C was used with -c (count only), some lines of context were
1371            accidentally printed for the final match.
1372    
1373        (g) Added the -H (--with-filename) option.
1374    
1375        (h) The combination of options -rh failed to suppress file names for files
1376            that were found from directory arguments.
1377    
1378        (i) Added the -D (--devices) and -d (--directories) options.
1379    
1380        (j) Added the -F (--fixed-strings) option.
1381    
1382        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1383    
1384        (l) Added the --colo(u)r option.
1385    
1386        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1387            is not present by default.
1388    
1389     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1390        items such as (?R) or (?1), when the recursion could match a number of
1391        alternatives. If it matched one of the alternatives, but subsequently,
1392        outside the recursion, there was a failure, the code tried to back up into
1393        the recursion. However, because of the way PCRE is implemented, this is not
1394        possible, and the result was an incorrect result from the match.
1395    
1396        In order to prevent this happening, the specification of recursion has
1397        been changed so that all such subpatterns are automatically treated as
1398        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1399    
1400     4. I had overlooked the fact that, in some locales, there are characters for
1401        which isalpha() is true but neither isupper() nor islower() are true. In
1402        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1403        and ordfeminine) are like this. This affected the treatment of \w and \W
1404        when they appeared in character classes, but not when they appeared outside
1405        a character class. The bit map for "word" characters is now created
1406        separately from the results of isalnum() instead of just taking it from the
1407        upper, lower, and digit maps. (Plus the underscore character, of course.)
1408    
1409     5. The above bug also affected the handling of POSIX character classes such as
1410        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1411        permanent tables. Instead, the bit maps for such a class were previously
1412        created as the appropriate unions of the upper, lower, and digit bitmaps.
1413        Now they are created by subtraction from the [[:word:]] class, which has
1414        its own bitmap.
1415    
1416     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1417        It is created by subtracting the vertical space characters (\x09, \x0a,
1418        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1419        subtraction was done in the overall bitmap for a character class, meaning
1420        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1421        be recognized. This bug has been fixed.
1422    
1423     7. Patches from the folks at Google:
1424    
1425          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1426          real life, but is still worth protecting against".
1427    
1428          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1429          regular expressions".
1430    
1431          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1432          have it.
1433    
1434          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1435          "configure" and the latter not, in order to fix a problem somebody had
1436          with compiling the Arg class on HP-UX.
1437    
1438          (e) Improve the error-handling of the C++ wrapper a little bit.
1439    
1440          (f) New tests for checking recursion limiting.
1441    
1442     8. The pcre_memmove() function, which is used only if the environment does not
1443        have a standard memmove() function (and is therefore rarely compiled),
1444        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1445        returning a result (though PCRE never actually uses the result).
1446    
1447     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1448        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1449        returned instead of calling malloc() with an overflowing number that would
1450        most likely cause subsequent chaos.
1451    
1452    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1453    
1454    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1455        with this option is matched, the nmatch and pmatch options of regexec() are
1456        ignored.
1457    
1458    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1459        provided in case anyone wants to the the POSIX interface with UTF-8
1460        strings.
1461    
1462    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1463        C++ linking (needed for some HP-UX environments).
1464    
1465    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1466        (unused parameter) and in the pcre_printint() function (omitted "default"
1467        switch label when the default is to do nothing).
1468    
1469    15. Added some code to make it possible, when PCRE is compiled as a C++
1470        library, to replace subject pointers for pcre_exec() with a smart pointer
1471        class, thus making it possible to process discontinuous strings.
1472    
1473    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1474        much the same function. They were added by different people who were trying
1475        to make PCRE easy to compile on non-Unix systems. It has been suggested
1476        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1477        for compiling on Windows systems. I have therefore replaced it with
1478        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1479        defaults to "extern" for C or "extern C" for C++, which works fine on
1480        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1481        SCOPE with something explicit in config.h. In addition:
1482    
1483        (a) pcreposix.h still had just "extern" instead of either of these macros;
1484            I have replaced it with PCRE_DATA_SCOPE.
1485    
1486        (b) Functions such as _pcre_xclass(), which are internal to the library,
1487            but external in the C sense, all had PCRE_EXPORT in their definitions.
1488            This is apparently wrong for the Windows case, so I have removed it.
1489            (It makes no difference on Unix-like systems.)
1490    
1491    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1492        of recursive calls to match(). This is different to MATCH_LIMIT because
1493        that limits the total number of calls to match(), not all of which increase
1494        the depth of recursion. Limiting the recursion depth limits the amount of
1495        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1496        when PCRE is compiled, and changed at run time. A patch from Google adds
1497        this functionality to the C++ interface.
1498    
1499    18. Changes to the handling of Unicode character properties:
1500    
1501        (a) Updated the table to Unicode 4.1.0.
1502    
1503        (b) Recognize characters that are not in the table as "Cn" (undefined).
1504    
1505        (c) I revised the way the table is implemented to a much improved format
1506            which includes recognition of ranges. It now supports the ranges that
1507            are defined in UnicodeData.txt, and it also amalgamates other
1508            characters into ranges. This has reduced the number of entries in the
1509            table from around 16,000 to around 3,000, thus reducing its size
1510            considerably. I realized I did not need to use a tree structure after
1511            all - a binary chop search is just as efficient. Having reduced the
1512            number of entries, I extended their size from 6 bytes to 8 bytes to
1513            allow for more data.
1514    
1515        (d) Added support for Unicode script names via properties such as \p{Han}.
1516    
1517    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1518        matching that character.
1519    
1520    20. When matching a repeated Unicode property with a minimum greater than zero,
1521        (for example \pL{2,}), PCRE could look past the end of the subject if it
1522        reached it while seeking the minimum number of characters. This could
1523        happen only if some of the characters were more than one byte long, because
1524        there is a check for at least the minimum number of bytes.
1525    
1526    21. Refactored the implementation of \p and \P so as to be more general, to
1527        allow for more different types of property in future. This has changed the
1528        compiled form incompatibly. Anybody with saved compiled patterns that use
1529        \p or \P will have to recompile them.
1530    
1531    22. Added "Any" and "L&" to the supported property types.
1532    
1533    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1534        but give a compile time error if the value is greater than 0xff.
1535    
1536    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1537        accidentally not being installed or uninstalled.
1538    
1539    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1540        made were to insert the current release number. This seemed silly, because
1541        it made things harder for people building PCRE on systems that don't run
1542        "configure". I have turned pcre.h into a distributed file, no longer built
1543        by "configure", with the version identification directly included. There is
1544        no longer a pcre.h.in file.
1545    
1546        However, this change necessitated a change to the pcre-config script as
1547        well. It is built from pcre-config.in, and one of the substitutions was the
1548        release number. I have updated configure.ac so that ./configure now finds
1549        the release number by grepping pcre.h.
1550    
1551    26. Added the ability to run the tests under valgrind.
1552    
1553    
1554    Version 6.4 05-Sep-05
1555    ---------------------
1556    
1557     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1558        "--" to be printed when multiple files were scanned, even when none of the
1559        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1560        consider it to be a bug, and have restored the previous behaviour.
1561    
1562     2. A couple of code tidies to get rid of compiler warnings.
1563    
1564     3. The pcretest program used to cheat by referring to symbols in the library
1565        whose names begin with _pcre_. These are internal symbols that are not
1566        really supposed to be visible externally, and in some environments it is
1567        possible to suppress them. The cheating is now confined to including
1568        certain files from the library's source, which is a bit cleaner.
1569    
1570     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1571        file's purpose clearer.
1572    
1573     5. Reorganized pcre_ucp_findchar().
1574    
1575    
1576    Version 6.3 15-Aug-05
1577    ---------------------
1578    
1579     1. The file libpcre.pc.in did not have general read permission in the tarball.
1580    
1581     2. There were some problems when building without C++ support:
1582    
1583        (a) If C++ support was not built, "make install" and "make test" still
1584            tried to test it.
1585    
1586        (b) There were problems when the value of CXX was explicitly set. Some
1587            changes have been made to try to fix these, and ...
1588    
1589        (c) --disable-cpp can now be used to explicitly disable C++ support.
1590    
1591        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1592            backslash in a target when C++ was disabled. This confuses some
1593            versions of "make", apparently. Using an intermediate variable solves
1594            this. (Same for CPP_LOBJ.)
1595    
1596     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1597        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1598        necessary on certain architectures.
1599    
1600     4. Added a setting of -export-symbols-regex to the link command to remove
1601        those symbols that are exported in the C sense, but actually are local
1602        within the library, and not documented. Their names all begin with
1603        "_pcre_". This is not a perfect job, because (a) we have to except some
1604        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1605        available (and never for static libraries). I have made a note to try to
1606        find a way round (a) in the future.
1607    
1608    
1609    Version 6.2 01-Aug-05
1610    ---------------------
1611    
1612     1. There was no test for integer overflow of quantifier values. A construction
1613        such as {1111111111111111} would give undefined results. What is worse, if
1614        a minimum quantifier for a parenthesized subpattern overflowed and became
1615        negative, the calculation of the memory size went wrong. This could have
1616        led to memory overwriting.
1617    
1618     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1619    
1620     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1621        operating environments where this matters.
1622    
1623     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1624        PCRE options from within the C++ wrapper.
1625    
1626     5. Named capturing subpatterns were not being correctly counted when a pattern
1627        was compiled. This caused two problems: (a) If there were more than 100
1628        such subpatterns, the calculation of the memory needed for the whole
1629        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1630        back references of the form \12, where the number was greater than 9, were
1631        not recognized as back references, even though there were sufficient
1632        previous subpatterns.
1633    
1634     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1635        versions of gcc, e.g. 2.95.4.
1636    
1637    
1638    Version 6.1 21-Jun-05
1639    ---------------------
1640    
1641     1. There was one reference to the variable "posix" in pcretest.c that was not
1642        surrounded by "#if !defined NOPOSIX".
1643    
1644     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1645        the cross-check on the old pcre_info() function, for the benefit of the
1646        cut-down version of PCRE that is currently imported into Exim.
1647    
1648     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1649        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1650        patterns that start (?i) but I don't think that matters. The use of (?i) is
1651        just an example; this all applies to the other options as well.
1652    
1653     4. Since libtool seems to echo the compile commands it is issuing, the output
1654        from "make" can be reduced a bit by putting "@" in front of each libtool
1655        compile command.
1656    
1657     5. Patch from the folks at Google for configure.in to be a bit more thorough
1658        in checking for a suitable C++ installation before trying to compile the
1659        C++ stuff. This should fix a reported problem when a compiler was present,
1660        but no suitable headers.
1661    
1662     6. The man pages all had just "PCRE" as their title. I have changed them to
1663        be the relevant file name. I have also arranged that these names are
1664        retained in the file doc/pcre.txt, which is a concatenation in text format
1665        of all the man pages except the little individual ones for each function.
1666    
1667     7. The NON-UNIX-USE file had not been updated for the different set of source
1668        files that come with release 6. I also added a few comments about the C++
1669        wrapper.
1670    
1671    
1672    Version 6.0 07-Jun-05
1673    ---------------------
1674    
1675     1. Some minor internal re-organization to help with my DFA experiments.
1676    
1677     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1678        didn't matter for the library itself when fully configured, but did matter
1679        when compiling without UCP support, or within Exim, where the ucp files are
1680        not imported.
1681    
1682     3. Refactoring of the library code to split up the various functions into
1683        different source modules. The addition of the new DFA matching code (see
1684        below) to a single monolithic source would have made it really too
1685        unwieldy, quite apart from causing all the code to be include in a
1686        statically linked application, when only some functions are used. This is
1687        relevant even without the DFA addition now that patterns can be compiled in
1688        one application and matched in another.
1689    
1690        The downside of splitting up is that there have to be some external
1691        functions and data tables that are used internally in different modules of
1692        the library but which are not part of the API. These have all had their
1693        names changed to start with "_pcre_" so that they are unlikely to clash
1694        with other external names.
1695    
1696     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1697        a different (DFA) algorithm. Although it is slower than the original
1698        function, it does have some advantages for certain types of matching
1699        problem.
1700    
1701     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1702        including restarting after a partial match.
1703    
1704     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1705        defined when compiling for Windows was sent to me. I have put it into the
1706        code, though I have no means of testing or verifying it.
1707    
1708     7. Added the pcre_refcount() auxiliary function.
1709    
1710     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1711        match before or at the first newline in the subject string. In pcretest,
1712        the /f option on a pattern can be used to set this.
1713    
1714     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1715        would behave wrongly. This has been present in PCRE since release 4.0.
1716    
1717    10. A number of changes to the pcregrep command:
1718    
1719        (a) Refactored how -x works; insert ^(...)$ instead of setting
1720            PCRE_ANCHORED and checking the length, in preparation for adding
1721            something similar for -w.
1722    
1723        (b) Added the -w (match as a word) option.
1724    
1725        (c) Refactored the way lines are read and buffered so as to have more
1726            than one at a time available.
1727    
1728        (d) Implemented a pcregrep test script.
1729    
1730        (e) Added the -M (multiline match) option. This allows patterns to match
1731            over several lines of the subject. The buffering ensures that at least
1732            8K, or the rest of the document (whichever is the shorter) is available
1733            for matching (and similarly the previous 8K for lookbehind assertions).
1734    
1735        (f) Changed the --help output so that it now says
1736    
1737              -w, --word-regex(p)
1738    
1739            instead of two lines, one with "regex" and the other with "regexp"
1740            because that confused at least one person since the short forms are the
1741            same. (This required a bit of code, as the output is generated
1742            automatically from a table. It wasn't just a text change.)
1743    
1744        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1745            option but starts with a hyphen. Could be a pattern or a path name
1746            starting with a hyphen, for instance.
1747    
1748        (h) "-" can be given as a file name to represent stdin.
1749    
1750        (i) When file names are being printed, "(standard input)" is used for
1751            the standard input, for compatibility with GNU grep. Previously
1752            "<stdin>" was used.
1753    
1754        (j) The option --label=xxx can be used to supply a name to be used for
1755            stdin when file names are being printed. There is no short form.
1756    
1757        (k) Re-factored the options decoding logic because we are going to add
1758            two more options that take data. Such options can now be given in four
1759            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1760    
1761        (l) Added the -A, -B, and -C options for requesting that lines of context
1762            around matches be printed.
1763    
1764        (m) Added the -L option to print the names of files that do not contain
1765            any matching lines, that is, the complement of -l.
1766    
1767        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1768            continue to scan other files.
1769    
1770        (o) The -s option was incorrectly implemented. For compatibility with other
1771            greps, it now suppresses the error message for a non-existent or non-
1772            accessible file (but not the return code). There is a new option called
1773            -q that suppresses the output of matching lines, which was what -s was
1774            previously doing.
1775    
1776        (p) Added --include and --exclude options to specify files for inclusion
1777            and exclusion when recursing.
1778    
1779    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1780        Hopefully, it now does.
1781    
1782    12. Missing cast in pcre_study().
1783    
1784    13. Added an "uninstall" target to the makefile.
1785    
1786    14. Replaced "extern" in the function prototypes in Makefile.in with
1787        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1788        world, but is set differently for Windows.
1789    
1790    15. Added a second compiling function called pcre_compile2(). The only
1791        difference is that it has an extra argument, which is a pointer to an
1792        integer error code. When there is a compile-time failure, this is set
1793        non-zero, in addition to the error test pointer being set to point to an
1794        error message. The new argument may be NULL if no error number is required
1795        (but then you may as well call pcre_compile(), which is now just a
1796        wrapper). This facility is provided because some applications need a
1797        numeric error indication, but it has also enabled me to tidy up the way
1798        compile-time errors are handled in the POSIX wrapper.
1799    
1800    16. Added VPATH=.libs to the makefile; this should help when building with one
1801        prefix path and installing with another. (Or so I'm told by someone who
1802        knows more about this stuff than I do.)
1803    
1804    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1805        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1806        match everything, including newlines. This is not POSIX-compatible, but
1807        somebody wanted the feature. From pcretest it can be activated by using
1808        both the P and the s flags.
1809    
1810    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1811    
1812    19. libpcre.pc was being incorrectly installed as executable.
1813    
1814    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1815        it now also looks for '\r' so that it will work unmodified on Windows.
1816    
1817    21. Added Google's contributed C++ wrapper to the distribution.
1818    
1819    22. Added some untidy missing memory free() calls in pcretest, to keep
1820        Electric Fence happy when testing.
1821    
1822    
1823    
1824    Version 5.0 13-Sep-04
1825    ---------------------
1826    
1827     1. Internal change: literal characters are no longer packed up into items
1828        containing multiple characters in a single byte-string. Each character
1829        is now matched using a separate opcode. However, there may be more than one
1830        byte in the character in UTF-8 mode.
1831    
1832     2. The pcre_callout_block structure has two new fields: pattern_position and
1833        next_item_length. These contain the offset in the pattern to the next match
1834        item, and its length, respectively.
1835    
1836     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1837        insertion of callouts before each pattern item. Added the /C option to
1838        pcretest to make use of this.
1839    
1840     4. On the advice of a Windows user, the lines
1841    
1842          #if defined(_WIN32) || defined(WIN32)
1843          _setmode( _fileno( stdout ), 0x8000 );
1844          #endif  /* defined(_WIN32) || defined(WIN32) */
1845    
1846        have been added to the source of pcretest. This apparently does useful
1847        magic in relation to line terminators.
1848    
1849     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1850        for the benefit of those environments where the "b" makes a difference.
1851    
1852     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1853        to know about it. I have put a hack into configure.in that adds in code
1854        to set GCC=yes if CC=icc. This seems to end up at a point in the
1855        generated configure script that is early enough to affect the setting of
1856        compiler options, which is what is needed, but I have no means of testing
1857        whether it really works. (The user who reported this had patched the
1858        generated configure script, which of course I cannot do.)
1859    
1860        LATER: After change 22 below (new libtool files), the configure script
1861        seems to know about icc (and also ecc). Therefore, I have commented out
1862        this hack in configure.in.
1863    
1864     7. Added support for pkg-config (2 patches were sent in).
1865    
1866     8. Negated POSIX character classes that used a combination of internal tables
1867        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1868        [[:^ascii]]. Typically, they would match almost any characters. The other
1869        POSIX classes were not broken in this way.
1870    
1871     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1872        to find the match, as PCRE was deluded into thinking that the match had to
1873        start at the start point or following a newline. The same bug applied to
1874        patterns with negative forward assertions or any backward assertions
1875        preceding ".*" at the start, unless the pattern required a fixed first
1876        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1877    
1878    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1879        starting at the last subject character, bytes beyond the end of the subject
1880        string were read.
1881    
1882    11. Renamed the variable "class" as "classbits" to make life easier for C++
1883        users. (Previously there was a macro definition, but it apparently wasn't
1884        enough.)
1885    
1886    12. Added the new field "tables" to the extra data so that tables can be passed
1887        in at exec time, or the internal tables can be re-selected. This allows
1888        a compiled regex to be saved and re-used at a later time by a different
1889        program that might have everything at different addresses.
1890    
1891    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1892        -R library as well as a -L library.
1893    
1894    14. The debugging options of pcretest (-d on the command line or D on a
1895        pattern) showed incorrect output for anything following an extended class
1896        that contained multibyte characters and which was followed by a quantifier.
1897    
1898    15. Added optional support for general category Unicode character properties
1899        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1900        support. It adds about 90K to the size of the library. The meanings of the
1901        inbuilt class escapes such as \d and \s have NOT been changed.
1902    
1903    16. Updated pcredemo.c to include calls to free() to release the memory for the
1904        compiled pattern.
1905    
1906    17. The generated file chartables.c was being created in the source directory
1907        instead of in the building directory. This caused the build to fail if the
1908        source directory was different from the building directory, and was
1909        read-only.
1910    
1911    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1912        file. No doubt somebody will tell me if they don't make sense... Also added
1913        Dan Mooney's comments about building on OpenVMS.
1914    
1915    19. Added support for partial matching via the PCRE_PARTIAL option for
1916        pcre_exec() and the \P data escape in pcretest.
1917    
1918    20. Extended pcretest with 3 new pattern features:
1919    
1920        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1921              write the compiled pattern to the file whose name is "rest-of-line".
1922              This is a straight binary dump of the data, with the saved pointer to
1923              the character tables forced to be NULL. The study data, if any, is
1924              written too. After writing, pcretest reads a new pattern.
1925    
1926        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1927              compiled pattern from the given file. There must not be any
1928              occurrences of "<" in the file name (pretty unlikely); if there are,
1929              pcretest will instead treat the initial "<" as a pattern delimiter.
1930              After reading in the pattern, pcretest goes on to read data lines as
1931              usual.
1932    
1933        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1934              and 16-bit fields in a compiled pattern, to simulate a pattern that
1935              was compiled on a host of opposite endianness.
1936    
1937    21. The pcre-exec() function can now cope with patterns that were compiled on
1938        hosts of opposite endianness, with this restriction:
1939    
1940          As for any compiled expression that is saved and used later, the tables
1941          pointer field cannot be preserved; the extra_data field in the arguments
1942          to pcre_exec() should be used to pass in a tables address if a value
1943          other than the default internal tables were used at compile time.
1944    
1945    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1946        now diagnosed as an error. Previously, most of the time, a negative number
1947        would have been treated as zero, but if in addition "ovector" was passed as
1948        NULL, a crash could occur.
1949    
1950    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1951        new versions from the libtool 1.5 distribution (the last one is a copy of
1952        a file called libtool.m4). This seems to have fixed the need to patch
1953        "configure" to support Darwin 1.3 (which I used to do). However, I still
1954        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1955        workstation).
1956    
1957    24. Changed the PCRE licence to be the more standard "BSD" licence.
1958    
1959    
1960    Version 4.5 01-Dec-03
1961    ---------------------
1962    
1963     1. There has been some re-arrangement of the code for the match() function so
1964        that it can be compiled in a version that does not call itself recursively.
1965        Instead, it keeps those local variables that need separate instances for
1966        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1967        needs to "recurse". Keeping track of where control must go is done by means
1968        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1969        hide most of the details from the main code, and operates only if
1970        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1971        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1972        operating.
1973    
1974        To make it easier for callers to provide specially tailored get/free
1975        functions for this usage, two new functions, pcre_stack_malloc, and
1976        pcre_stack_free, are used. They are always called in strict stacking order,
1977        and the size of block requested is always the same.
1978    
1979        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1980        PCRE has been compiled to use the stack or the heap for recursion. The
1981        -C option of pcretest uses this to show which version is compiled.
1982    
1983        A new data escape \S, is added to pcretest; it causes the amounts of store
1984        obtained and freed by both kinds of malloc/free at match time to be added
1985        to the output.
1986    
1987     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1988        what's available on my current Linux desktop machine.
1989    
1990     3. When matching a UTF-8 string, the test for a valid string at the start has
1991        been extended. If start_offset is not zero, PCRE now checks that it points
1992        to a byte that is the start of a UTF-8 character. If not, it returns
1993        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1994        this is necessary because there may be backward assertions in the pattern.
1995        When matching the same subject several times, it may save resources to use
1996        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1997    
1998     4. The code for checking the validity of UTF-8 strings has been tightened so
1999        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2000        containing "overlong sequences".
2001    
2002     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2003        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2004        should have been "&", but it just so happened that all the cases this let
2005        through by mistake were picked up later in the function.
2006    
2007     6. I had used a variable called "isblank" - this is a C99 function, causing
2008        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2009    
2010     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2011        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2012        so the version is shown; (c) stop "make test" echoing "./RunTest".
2013    
2014     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2015    
2016     9. The prototype for memmove() for systems that don't have it was using
2017        size_t, but the inclusion of the header that defines size_t was later. I've
2018        moved the #includes for the C headers earlier to avoid this.
2019    
2020    10. Added some adjustments to the code to make it easier to compiler on certain
2021        special systems:
2022    
2023          (a) Some "const" qualifiers were missing.
2024          (b) Added the macro EXPORT before all exported functions; by default this
2025              is defined to be empty.
2026          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2027              that it reads its output file name as an argument instead of writing
2028              to the standard output and assuming this can be redirected.
2029    
2030    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2031        class containing characters with values greater than 255, PCRE compilation
2032        went into a loop.
2033    
2034    12. A recursive reference to a subpattern that was within another subpattern
2035        that had a minimum quantifier of zero caused PCRE to crash. For example,
2036        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2037        recursion. If the recursively-called subpattern itself had a zero repeat,
2038        that was OK.
2039    
2040    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2041        buffer into which it was copied (for escape processing) was still set at
2042        1024, so long lines caused crashes.
2043    
2044    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2045        "internal error: code overflow...". This applied to any character class
2046        that was followed by a possessive quantifier.
2047    
2048    15. Modified the Makefile to add libpcre.la as a prerequisite for
2049        libpcreposix.la because I was told this is needed for a parallel build to
2050        work.
2051    
2052    16. If a pattern that contained .* following optional items at the start was
2053        studied, the wrong optimizing data was generated, leading to matching
2054        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2055        matching string must start with a or b or c. The correct conclusion for
2056        this pattern is that a match can start with any character.
2057    
2058    
2059    Version 4.4 13-Aug-03
2060    ---------------------
2061    
2062     1. In UTF-8 mode, a character class containing characters with values between
2063        127 and 255 was not handled correctly if the compiled pattern was studied.
2064        In fixing this, I have also improved the studying algorithm for such
2065        classes (slightly).
2066    
2067     2. Three internal functions had redundant arguments passed to them. Removal
2068        might give a very teeny performance improvement.
2069    
2070     3. Documentation bug: the value of the capture_top field in a callout is *one
2071        more than* the number of the hightest numbered captured substring.
2072    
2073     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2074        in incorrectly linking with a previously installed version. They now link
2075        explicitly with libpcre.la.
2076    
2077     5. configure.in no longer needs to recognize Cygwin specially.
2078    
2079     6. A problem in pcre.in for Windows platforms is fixed.
2080    
2081     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2082        pcretest, it used to include the size of the study block as part of its
2083        output. Unfortunately, the structure contains a field that has a different
2084        size on different hardware architectures. This meant that the tests that
2085        showed this size failed. As the block is currently always of a fixed size,
2086        this information isn't actually particularly useful in pcretest output, so
2087        I have just removed it.
2088    
2089     8. Three pre-processor statements accidentally did not start in column 1.
2090        Sadly, there are *still* compilers around that complain, even though
2091        standard C has not required this for well over a decade. Sigh.
2092    
2093     9. In pcretest, the code for checking callouts passed small integers in the
2094        callout_data field, which is a void * field. However, some picky compilers
2095        complained about the casts involved for this on 64-bit systems. Now
2096        pcretest passes the address of the small integer instead, which should get
2097        rid of the warnings.
2098    
2099    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2100        both compile and run time, and gives an error if an invalid UTF-8 sequence
2101        is found. There is a option for disabling this check in cases where the
2102        string is known to be correct and/or the maximum performance is wanted.
2103    
2104    11. In response to a bug report, I changed one line in Makefile.in from
2105    
2106            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2107        to
2108            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2109    
2110        to look similar to other lines, but I have no way of telling whether this
2111        is the right thing to do, as I do not use Windows. No doubt I'll get told
2112        if it's wrong...
2113    
2114    
2115    Version 4.3 21-May-03
2116    ---------------------
2117    
2118    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2119       Makefile.
2120    
2121    2. Some refactoring to improve the quality of the code:
2122    
2123       (i)   The utf8_table... variables are now declared "const".
2124    
2125       (ii)  The code for \cx, which used the "case flipping" table to upper case
2126             lower case letters, now just substracts 32. This is ASCII-specific,
2127             but the whole concept of \cx is ASCII-specific, so it seems
2128             reasonable.
2129    
2130       (iii) PCRE was using its character types table to recognize decimal and
2131             hexadecimal digits in the pattern. This is silly, because it handles
2132             only 0-9, a-f, and A-F, but the character types table is locale-
2133             specific, which means strange things might happen. A private
2134             table is now used for this - though it costs 256 bytes, a table is
2135             much faster than multiple explicit tests. Of course, the standard
2136             character types table is still used for matching digits in subject
2137             strings against \d.
2138    
2139       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2140             ending in _t are). So I've renamed it as ESC_tee.
2141    
2142    3. The first argument for regexec() in the POSIX wrapper should have been
2143       defined as "const".
2144    
2145    4. Changed pcretest to use malloc() for its buffers so that they can be
2146       Electric Fenced for debugging.
2147    
2148    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2149       to read one or more bytes before the start of the subject string. Often this
2150       had no effect on PCRE's behaviour, but in some circumstances it could
2151       provoke a segmentation fault.
2152    
2153    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2154       to try to read one or more bytes before the start of the subject string.
2155    
2156    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2157       UTF-8 support could misbehave in various ways if the subject string
2158       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2159       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2160       back over UTF-8 characters.)
2161    
2162    
2163    Version 4.2 14-Apr-03
2164    ---------------------
2165    
2166    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2167    
2168    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2169         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2170         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2171         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2172         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2173           and BUILD_EXEEXT
2174         Note: automatic setting of the BUILD variables is not yet working
2175         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2176           compile-time but not at link-time
2177         [LINK]: use for linking executables only
2178         make different versions for Windows and non-Windows
2179         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2180           libraries
2181         [LINK_FOR_BUILD]: new variable
2182         [OBJEXT]: use throughout
2183         [EXEEXT]: use throughout
2184         <winshared>: new target
2185         <wininstall>: new target
2186         <dftables.o>: use native compiler
2187         <dftables>: use native linker
2188         <install>: handle Windows platform correctly
2189         <clean>: ditto
2190         <check>: ditto
2191         copy DLL to top builddir before testing
2192    
2193       As part of these changes, -no-undefined was removed again. This was reported
2194       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2195       in any case.
2196    
2197    3. Some tidies to get rid of compiler warnings:
2198    
2199       . In the match_data structure, match_limit was an unsigned long int, whereas
2200         match_call_count was an int. I've made them both unsigned long ints.
2201    
2202       . In pcretest the fact that a const uschar * doesn't automatically cast to
2203         a void * provoked a warning.
2204    
2205       . Turning on some more compiler warnings threw up some "shadow" variables
2206         and a few more missing casts.
2207    
2208    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2209       option, a class that contained a single character with a value between 128
2210       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2211    
2212    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2213       option, a class that contained several characters, but with at least one
2214       whose value was between 128 and 255 caused PCRE to crash.
2215    
2216    
2217  Version 4.1 12-Mar-03  Version 4.1 12-Mar-03
2218  ---------------------  ---------------------
2219    

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