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revision 69 by nigel, Sat Feb 24 21:40:18 2007 UTC revision 425 by ph10, Mon Aug 17 14:48:48 2009 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.00 ??-???-??
5    ----------------------
6    
7    1.  The table for translating pcre_compile() error codes into POSIX error codes
8        was out-of-date, and there was no check on the pcre_compile() error code
9        being within the table. This could lead to an OK return being given in
10        error.
11    
12    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
13        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14        in a Windows environment.
15    
16    3.  The pcregrep --count option prints the count for each file even when it is
17        zero, as does GNU grep. However, pcregrep was also printing all files when
18        --files-with-matches was added. Now, when both options are given, it prints
19        counts only for those files that have at least one match. (GNU grep just
20        prints the file name in this circumstance, but including the count seems
21        more useful - otherwise, why use --count?) Also ensured that the
22        combination -clh just lists non-zero counts, with no names.
23    
24    4.  The long form of the pcregrep -F option was incorrectly implemented as
25        --fixed_strings instead of --fixed-strings. This is an incompatible change,
26        but it seems right to fix it, and I didn't think it was worth preserving
27        the old behaviour.
28    
29    5.  The command line items --regex=pattern and --regexp=pattern were not
30        recognized by pcregrep, which required --regex pattern or --regexp pattern
31        (with a space rather than an '='). The man page documented the '=' forms,
32        which are compatible with GNU grep; these now work.
33    
34    6.  No libpcreposix.pc file was created for pkg-config; there was just
35        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
36    
37    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38        when UCP support is not needed, by modifying the Python script that
39        generates it from Unicode data files. This should not matter if the module
40        is correctly used as a library, but I received one complaint about 50K of
41        unwanted data. My guess is that the person linked everything into his
42        program rather than using a library. Anyway, it does no harm.
43    
44    
45    Version 7.9 11-Apr-09
46    ---------------------
47    
48    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
49        (pcretest), all targets were linked against these libraries. This included
50        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
51        libraries. This caused unwanted dependencies to be created. This problem
52        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
53        pcretest is linked with readline.
54    
55    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
56        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
57        moved outside it again, because FALSE and TRUE are already defined in AIX,
58        but BOOL is not.
59    
60    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
61        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
62    
63    4.  The pcregrep documentation said spaces were inserted as well as colons (or
64        hyphens) following file names and line numbers when outputting matching
65        lines. This is not true; no spaces are inserted. I have also clarified the
66        wording for the --colour (or --color) option.
67    
68    5.  In pcregrep, when --colour was used with -o, the list of matching strings
69        was not coloured; this is different to GNU grep, so I have changed it to be
70        the same.
71    
72    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
73        each matching line was coloured. Now it goes on to look for further matches
74        of any of the test patterns, which is the same behaviour as GNU grep.
75    
76    7.  A pattern that could match an empty string could cause pcregrep to loop; it
77        doesn't make sense to accept an empty string match in pcregrep, so I have
78        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
79        seems to be how GNU grep behaves.
80    
81    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
82        start or after a newline", because the conditional assertion was not being
83        correctly handled. The rule now is that both the assertion and what follows
84        in the first alternative must satisfy the test.
85    
86    9.  If auto-callout was enabled in a pattern with a conditional group whose
87        condition was an assertion, PCRE could crash during matching, both with
88        pcre_exec() and pcre_dfa_exec().
89    
90    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
91        used for matching.
92    
93    11. Unicode property support in character classes was not working for
94        characters (bytes) greater than 127 when not in UTF-8 mode.
95    
96    12. Added the -M command line option to pcretest.
97    
98    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
99    
100    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
101    
102    16. Added comments and documentation about mis-use of no_arg in the C++
103        wrapper.
104    
105    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
106        from Martin Jerabek that uses macro names for all relevant character and
107        string constants.
108    
109    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
110        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
111        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
112        these, but not everybody uses configure.
113    
114    19. A conditional group that had only one branch was not being correctly
115        recognized as an item that could match an empty string. This meant that an
116        enclosing group might also not be so recognized, causing infinite looping
117        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
118        with the subject "ab", where knowledge that the repeated group can match
119        nothing is needed in order to break the loop.
120    
121    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
122        exec(), but without supplying a callout function, matching went wrong.
123    
124    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
125        leak if the size of the offset vector was greater than 30. When the vector
126        is smaller, the saved offsets during recursion go onto a local stack
127        vector, but for larger vectors malloc() is used. It was failing to free
128        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
129        error, in fact).
130    
131    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
132        heapframe that is used only when UTF-8 support is enabled. This caused no
133        problem, but was untidy.
134    
135    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
136        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
137        included within another project.
138    
139    24. Steven Van Ingelgem's patches to add more options to the CMake support,
140        slightly modified by me:
141    
142          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
143              not building pcregrep.
144    
145          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
146              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
147    
148    25. Forward references, both numeric and by name, in patterns that made use of
149        duplicate group numbers, could behave incorrectly or give incorrect errors,
150        because when scanning forward to find the reference group, PCRE was not
151        taking into account the duplicate group numbers. A pattern such as
152        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
153    
154    26. Changed a few more instances of "const unsigned char *" to USPTR, making
155        the feature of a custom pointer more persuasive (as requested by a user).
156    
157    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
158        pcretest.c, inside #ifndefs, because it seems they are sometimes already
159        pre-defined.
160    
161    28. Added support for (*UTF8) at the start of a pattern.
162    
163    29. Arrange for flags added by the "release type" setting in CMake to be shown
164        in the configuration summary.
165    
166    
167    Version 7.8 05-Sep-08
168    ---------------------
169    
170    1.  Replaced UCP searching code with optimized version as implemented for Ad
171        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
172        stage table and inline lookup instead of a function, giving speed ups of 2
173        to 5 times on some simple patterns that I tested. Permission was given to
174        distribute the MultiStage2.py script that generates the tables (it's not in
175        the tarball, but is in the Subversion repository).
176    
177    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
178        scripts.
179    
180    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
181        a group with a zero qualifier. The result of the study could be incorrect,
182        or the function might crash, depending on the pattern.
183    
184    4.  Caseless matching was not working for non-ASCII characters in back
185        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
186        It now works when Unicode Property Support is available.
187    
188    5.  In pcretest, an escape such as \x{de} in the data was always generating
189        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
190        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
191        truncation.
192    
193    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
194    
195    7.  Added two (int) casts to pcregrep when printing the difference of two
196        pointers, in case they are 64-bit values.
197    
198    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
199        test 2 if it fails.
200    
201    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
202        and a #define of that name to empty if it is not externally set. This is to
203        allow users of MSVC to set it if necessary.
204    
205    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
206        the convenience functions in the pcre_get.c source file.
207    
208    11. An option change at the start of a pattern that had top-level alternatives
209        could cause overwriting and/or a crash. This command provoked a crash in
210        some environments:
211    
212          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
213    
214        This potential security problem was recorded as CVE-2008-2371.
215    
216    12. For a pattern where the match had to start at the beginning or immediately
217        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
218        pcre_dfa_exec() could read past the end of the passed subject if there was
219        no match. To help with detecting such bugs (e.g. with valgrind), I modified
220        pcretest so that it places the subject at the end of its malloc-ed buffer.
221    
222    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
223        exec() might read past the end of the data buffer in UTF-8 mode.
224    
225    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
226        the data contained the byte 0x85 as part of a UTF-8 character within its
227        first line. This applied both to normal and DFA matching.
228    
229    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
230        /^[^d]*?$/8 failed to match "abc".
231    
232    16. Added a missing copyright notice to pcrecpp_internal.h.
233    
234    17. Make it more clear in the documentation that values returned from
235        pcre_exec() in ovector are byte offsets, not character counts.
236    
237    18. Tidied a few places to stop certain compilers from issuing warnings.
238    
239    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
240        supplied by Stefan Weber. I made a further small update for 7.8 because
241        there is a change of source arrangements: the pcre_searchfuncs.c module is
242        replaced by pcre_ucd.c.
243    
244    
245    Version 7.7 07-May-08
246    ---------------------
247    
248    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
249        a string to a long long, pretend we don't even have a long long." This is
250        done by checking for the strtoq, strtoll, and _strtoi64 functions.
251    
252    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
253        pre-7.6 versions, which defined a global no_arg variable instead of putting
254        it in the RE class. (See also #8 below.)
255    
256    3.  Remove a line of dead code, identified by coverity and reported by Nuno
257        Lopes.
258    
259    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
260    
261        (1) The include/exclude patterns were being applied to the whole pathnames
262            of files, instead of just to the final components.
263    
264        (2) If there was more than one level of directory, the subdirectories were
265            skipped unless they satisfied the include/exclude conditions. This is
266            inconsistent with GNU grep (and could even be seen as contrary to the
267            pcregrep specification - which I improved to make it absolutely clear).
268            The action now is always to scan all levels of directory, and just
269            apply the include/exclude patterns to regular files.
270    
271    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
272        --exclude_dir in the tests to avoid scanning .svn directories.
273    
274    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
275        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
276        doesn't support NULs in patterns.
277    
278    7.  Added some missing "const"s to declarations of static tables in
279        pcre_compile.c and pcre_dfa_exec.c.
280    
281    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
282        caused by fix #2  above. (Subsequently also a second patch to fix the
283        first patch. And a third patch - this was a messy problem.)
284    
285    9.  Applied Craig's patch to remove the use of push_back().
286    
287    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
288        matching function regexec().
289    
290    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
291        which, however, unlike Perl's \g{...}, are subroutine calls, not back
292        references. PCRE supports relative numbers with this syntax (I don't think
293        Oniguruma does).
294    
295    12. Previously, a group with a zero repeat such as (...){0} was completely
296        omitted from the compiled regex. However, this means that if the group
297        was called as a subroutine from elsewhere in the pattern, things went wrong
298        (an internal error was given). Such groups are now left in the compiled
299        pattern, with a new opcode that causes them to be skipped at execution
300        time.
301    
302    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
303        to the way PCRE behaves:
304    
305        (a) A lone ] character is dis-allowed (Perl treats it as data).
306    
307        (b) A back reference to an unmatched subpattern matches an empty string
308            (Perl fails the current match path).
309    
310        (c) A data ] in a character class must be notated as \] because if the
311            first data character in a class is ], it defines an empty class. (In
312            Perl it is not possible to have an empty class.) The empty class []
313            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
314            The negative empty class [^] matches any one character, independently
315            of the DOTALL setting.
316    
317    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
318        non-existent subpattern following a character class starting with ']' and
319        containing () gave an internal compiling error instead of "reference to
320        non-existent subpattern". Fortunately, when the pattern did exist, the
321        compiled code was correct. (When scanning forwards to check for the
322        existencd of the subpattern, it was treating the data ']' as terminating
323        the class, so got the count wrong. When actually compiling, the reference
324        was subsequently set up correctly.)
325    
326    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
327        it was being rejected as not supported by pcre_dfa_exec(), even though
328        other assertions are supported. I have made pcre_dfa_exec() support
329        (*FAIL).
330    
331    16. The implementation of 13c above involved the invention of a new opcode,
332        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
333        cannot be changed at match time, I realized I could make a small
334        improvement to matching performance by compiling OP_ALLANY instead of
335        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
336        on the OP_ANY path.
337    
338    17. Compiling pcretest on Windows with readline support failed without the
339        following two fixes: (1) Make the unistd.h include conditional on
340        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
341    
342    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
343        ncurses library to be included for pcretest when ReadLine support is
344        requested, but also to allow for it to be overridden. This patch came from
345        Daniel Bergström.
346    
347    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
348        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
349        any errors with the current Unicode tables. Thanks to Peter Kankowski for
350        spotting this.
351    
352    
353    Version 7.6 28-Jan-08
354    ---------------------
355    
356    1.  A character class containing a very large number of characters with
357        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
358        overflow.
359    
360    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
361        HAVE_LONG_LONG is not defined.
362    
363    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
364        bring them up to date and include new features. This patch includes:
365    
366        - Fixed PH's badly added libz and libbz2 support.
367        - Fixed a problem with static linking.
368        - Added pcredemo. [But later removed - see 7 below.]
369        - Fixed dftables problem and added an option.
370        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
371            HAVE_LONG_LONG.
372        - Added readline support for pcretest.
373        - Added an listing of the option settings after cmake has run.
374    
375    4.  A user submitted a patch to Makefile that makes it easy to create
376        "pcre.dll" under mingw when using Configure/Make. I added stuff to
377        Makefile.am that cause it to include this special target, without
378        affecting anything else. Note that the same mingw target plus all
379        the other distribution libraries and programs are now supported
380        when configuring with CMake (see 6 below) instead of with
381        Configure/Make.
382    
383    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
384        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
385        exported in the Windows port". It has not yet been confirmed that the patch
386        solves the problem, but it does no harm.
387    
388    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
389        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
390        with CMake, and also correct the comment about stack recursion.
391    
392    7.  Remove the automatic building of pcredemo from the ./configure system and
393        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
394        of a program that users should build themselves after PCRE is installed, so
395        building it automatically is not really right. What is more, it gave
396        trouble in some build environments.
397    
398    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
399    
400    
401    Version 7.5 10-Jan-08
402    ---------------------
403    
404    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
405        values in parens when parsing an RE using the C++ wrapper."
406    
407    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
408        Characters greater than 255 were excluded from the class instead of being
409        included.
410    
411    3.  The same bug as (2) above applied to negated POSIX classes such as
412        [:^space:].
413    
414    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
415        defined or documented. It seems to have been a typo for PCRE_STATIC, so
416        I have changed it.
417    
418    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
419        first named subpattern) and a construct such as (?&a) would reference the
420        first named subpattern whose name started with "a" (in other words, the
421        length check was missing). Both these problems are fixed. "Subpattern name
422        expected" is now given for (?&) (a zero-length name), and this patch also
423        makes it give the same error for \k'' (previously it complained that that
424        was a reference to a non-existent subpattern).
425    
426    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
427        this is right because (?- can be followed by option settings as well as by
428        digits. I have, however, made the messages clearer.
429    
430    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
431        than the number used in the conditional) now cause a compile-time error.
432        This is actually not compatible with Perl, which accepts such patterns, but
433        treats the conditional as always being FALSE (as PCRE used to), but it
434        seems to me that giving a diagnostic is better.
435    
436    8.  Change "alphameric" to the more common word "alphanumeric" in comments
437        and messages.
438    
439    9.  Fix two occurrences of "backslash" in comments that should have been
440        "backspace".
441    
442    10. Remove two redundant lines of code that can never be obeyed (their function
443        was moved elsewhere).
444    
445    11. The program that makes PCRE's Unicode character property table had a bug
446        which caused it to generate incorrect table entries for sequences of
447        characters that have the same character type, but are in different scripts.
448        It amalgamated them into a single range, with the script of the first of
449        them. In other words, some characters were in the wrong script. There were
450        thirteen such cases, affecting characters in the following ranges:
451    
452          U+002b0 - U+002c1
453          U+0060c - U+0060d
454          U+0061e - U+00612
455          U+0064b - U+0065e
456          U+0074d - U+0076d
457          U+01800 - U+01805
458          U+01d00 - U+01d77
459          U+01d9b - U+01dbf
460          U+0200b - U+0200f
461          U+030fc - U+030fe
462          U+03260 - U+0327f
463          U+0fb46 - U+0fbb1
464          U+10450 - U+1049d
465    
466    12. The -o option (show only the matching part of a line) for pcregrep was not
467        compatible with GNU grep in that, if there was more than one match in a
468        line, it showed only the first of them. It now behaves in the same way as
469        GNU grep.
470    
471    13. If the -o and -v options were combined for pcregrep, it printed a blank
472        line for every non-matching line. GNU grep prints nothing, and pcregrep now
473        does the same. The return code can be used to tell if there were any
474        non-matching lines.
475    
476    14. Added --file-offsets and --line-offsets to pcregrep.
477    
478    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
479        infinitely looping recursion. The bug was that positive lookaheads were not
480        being skipped when checking for a possible empty match (negative lookaheads
481        and both kinds of lookbehind were skipped).
482    
483    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
484        inclusion of <windows.h> to before rather than after the definition of
485        INVALID_FILE_ATTRIBUTES (patch from David Byron).
486    
487    17. Specifying a possessive quantifier with a specific limit for a Unicode
488        character property caused pcre_compile() to compile bad code, which led at
489        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
490        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
491        caused the error; without that there was no problem.
492    
493    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
494    
495    19. Added --enable-pcretest-libreadline.
496    
497    20. In pcrecpp.cc, the variable 'count' was incremented twice in
498        RE::GlobalReplace(). As a result, the number of replacements returned was
499        double what it should be. I removed one of the increments, but Craig sent a
500        later patch that removed the other one (the right fix) and added unit tests
501        that check the return values (which was not done before).
502    
503    21. Several CMake things:
504    
505        (1) Arranged that, when cmake is used on Unix, the libraries end up with
506            the names libpcre and libpcreposix, not just pcre and pcreposix.
507    
508        (2) The above change means that pcretest and pcregrep are now correctly
509            linked with the newly-built libraries, not previously installed ones.
510    
511        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
512    
513    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
514        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
515        UTF-8 newline character). The key issue is that the pattern starts .*;
516        this means that the match must be either at the beginning, or after a
517        newline. The bug was in the code for advancing after a failed match and
518        checking that the new position followed a newline. It was not taking
519        account of UTF-8 characters correctly.
520    
521    23. PCRE was behaving differently from Perl in the way it recognized POSIX
522        character classes. PCRE was not treating the sequence [:...:] as a
523        character class unless the ... were all letters. Perl, however, seems to
524        allow any characters between [: and :], though of course it rejects as
525        unknown any "names" that contain non-letters, because all the known class
526        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
527        for example, whereas PCRE did not - it did not recognize a POSIX character
528        class. This seemed a bit dangerous, so the code has been changed to be
529        closer to Perl. The behaviour is not identical to Perl, because PCRE will
530        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
531        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
532        Perl does, and where it didn't before.
533    
534    24. Rewrite so as to remove the single use of %n from pcregrep because in some
535        Windows environments %n is disabled by default.
536    
537    
538    Version 7.4 21-Sep-07
539    ---------------------
540    
541    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
542        means that a class such as [\s] counted as "explicit reference to CR or
543        LF". That isn't really right - the whole point of the change was to try to
544        help when there was an actual mention of one of the two characters. So now
545        the change happens only if \r or \n (or a literal CR or LF) character is
546        encountered.
547    
548    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
549        of both had grown to the point where there were only 3 bits left.
550        Fortunately, there was spare space in the data structure, and so I have
551        moved the internal flags into a new 16-bit field to free up more option
552        bits.
553    
554    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
555        but did not set the internal JCHANGED flag - either of these is enough to
556        control the way the "get" function works - but the PCRE_INFO_JCHANGED
557        facility is supposed to tell if (?J) was ever used, so now (?J) at the
558        start sets both bits.
559    
560    4.  Added options (at build time, compile time, exec time) to change \R from
561        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
562    
563    5.  doc/pcresyntax.html was missing from the distribution.
564    
565    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
566        compatibility, even though it is no longer used.
567    
568    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
569        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
570        windows.h file is present (where different names are used). [This was
571        reversed later after testing - see 16 below.]
572    
573    8.  Changed all #include <config.h> to #include "config.h". There were also
574        some further <pcre.h> cases that I changed to "pcre.h".
575    
576    9.  When pcregrep was used with the --colour option, it missed the line ending
577        sequence off the lines that it output.
578    
579    10. It was pointed out to me that arrays of string pointers cause lots of
580        relocations when a shared library is dynamically loaded. A technique of
581        using a single long string with a table of offsets can drastically reduce
582        these. I have refactored PCRE in four places to do this. The result is
583        dramatic:
584    
585          Originally:                          290
586          After changing UCP table:            187
587          After changing error message table:   43
588          After changing table of "verbs"       36
589          After changing table of Posix names   22
590    
591        Thanks to the folks working on Gregex for glib for this insight.
592    
593    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
594        unicode-properties was also set.
595    
596    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
597    
598    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
599        checked only for CRLF.
600    
601    14. Added casts to pcretest.c to avoid compiler warnings.
602    
603    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
604    
605    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
606        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
607        entirely. This removes changes made in 7 above.
608    
609    17. The CMake files have been updated, and there is now more information about
610        building with CMake in the NON-UNIX-USE document.
611    
612    
613    Version 7.3 28-Aug-07
614    ---------------------
615    
616     1. In the rejigging of the build system that eventually resulted in 7.1, the
617        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
618        brackets there is not right, since it causes compilers to look for an
619        installed pcre.h, not the version that is in the source that is being
620        compiled (which of course may be different). I have changed it back to:
621    
622          #include "pcre.h"
623    
624        I have a vague recollection that the change was concerned with compiling in
625        different directories, but in the new build system, that is taken care of
626        by the VPATH setting the Makefile.
627    
628     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
629        when the subject happened to end in the byte 0x85 (e.g. if the last
630        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
631        characters but of course it shouldn't be taken as a newline when it is part
632        of another character. The bug was that, for an unlimited repeat of . in
633        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
634        characters when looking for a newline.
635    
636     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
637    
638     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
639        in debug output.
640    
641     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
642        long printing in the pcrecpp unittest when running under MinGW.
643    
644     6. ESC_K was left out of the EBCDIC table.
645    
646     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
647        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
648        limit also applies to "virtual nesting" when a pattern is recursive, and in
649        this case 1000 isn't so big. I have been able to remove this limit at the
650        expense of backing off one optimization in certain circumstances. Normally,
651        when pcre_exec() would call its internal match() function recursively and
652        immediately return the result unconditionally, it uses a "tail recursion"
653        feature to save stack. However, when a subpattern that can match an empty
654        string has an unlimited repetition quantifier, it no longer makes this
655        optimization. That gives it a stack frame in which to save the data for
656        checking that an empty string has been matched. Previously this was taken
657        from the 1000-entry workspace that had been reserved. So now there is no
658        explicit limit, but more stack is used.
659    
660     8. Applied Daniel's patches to solve problems with the import/export magic
661        syntax that is required for Windows, and which was going wrong for the
662        pcreposix and pcrecpp parts of the library. These were overlooked when this
663        problem was solved for the main library.
664    
665     9. There were some crude static tests to avoid integer overflow when computing
666        the size of patterns that contain repeated groups with explicit upper
667        limits. As the maximum quantifier is 65535, the maximum group length was
668        set at 30,000 so that the product of these two numbers did not overflow a
669        32-bit integer. However, it turns out that people want to use groups that
670        are longer than 30,000 bytes (though not repeat them that many times).
671        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
672        made it possible to implement the integer overflow checks in a much more
673        dynamic way, which I have now done. The artificial limitation on group
674        length has been removed - we now have only the limit on the total length of
675        the compiled pattern, which depends on the LINK_SIZE setting.
676    
677    10. Fixed a bug in the documentation for get/copy named substring when
678        duplicate names are permitted. If none of the named substrings are set, the
679        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
680        empty string.
681    
682    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
683        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
684        because the ] is interpreted as the first data character and the
685        terminating ] is not found. PCRE has been made compatible with Perl in this
686        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
687        cause memory overwriting.
688    
689    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
690        string has been matched (to stop an infinite loop). It was not recognizing
691        a conditional subpattern that could match an empty string if that
692        subpattern was within another subpattern. For example, it looped when
693        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
694        condition was not nested. This bug has been fixed.
695    
696    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
697        past the start of the subject in the presence of bytes with the top bit
698        set, for example "\x8aBCD".
699    
700    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
701        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
702    
703    14. Optimized (?!) to (*FAIL).
704    
705    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
706        This restricts code points to be within the range 0 to 0x10FFFF, excluding
707        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
708        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
709        does: it's just the validity check that is more restrictive.
710    
711    16. Inserted checks for integer overflows during escape sequence (backslash)
712        processing, and also fixed erroneous offset values for syntax errors during
713        backslash processing.
714    
715    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
716        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
717    
718    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
719        caused an overrun.
720    
721    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
722        something other than just ASCII characters) inside a group that had an
723        unlimited repeat caused a loop at compile time (while checking to see
724        whether the group could match an empty string).
725    
726    20. Debugging a pattern containing \p or \P could cause a crash. For example,
727        [\P{Any}] did so. (Error in the code for printing property names.)
728    
729    21. An orphan \E inside a character class could cause a crash.
730    
731    22. A repeated capturing bracket such as (A)? could cause a wild memory
732        reference during compilation.
733    
734    23. There are several functions in pcre_compile() that scan along a compiled
735        expression for various reasons (e.g. to see if it's fixed length for look
736        behind). There were bugs in these functions when a repeated \p or \P was
737        present in the pattern. These operators have additional parameters compared
738        with \d, etc, and these were not being taken into account when moving along
739        the compiled data. Specifically:
740    
741        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
742            length.
743    
744        (b) An item such as \pL+ within a repeated group could cause crashes or
745            loops.
746    
747        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
748            "reference to non-existent subpattern" error.
749    
750        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
751    
752    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
753        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
754    
755    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
756    
757    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
758        character were causing crashes (broken optimization).
759    
760    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
761        \p or \P) caused a compile-time loop.
762    
763    28. More problems have arisen in unanchored patterns when CRLF is a valid line
764        break. For example, the unstudied pattern [\r\n]A does not match the string
765        "\r\nA" because change 7.0/46 below moves the current point on by two
766        characters after failing to match at the start. However, the pattern \nA
767        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
768        the same is true. There doesn't seem any very clean way out of this, but
769        what I have chosen to do makes the common cases work: PCRE now takes note
770        of whether there can be an explicit match for \r or \n anywhere in the
771        pattern, and if so, 7.0/46 no longer applies. As part of this change,
772        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
773        pattern has explicit CR or LF references.
774    
775    29. Added (*CR) etc for changing newline setting at start of pattern.
776    
777    
778    Version 7.2 19-Jun-07
779    ---------------------
780    
781     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
782        which is apparently normally available under Windows.
783    
784     2. Re-jig the pcregrep tests with different newline settings in an attempt
785        to make them independent of the local environment's newline setting.
786    
787     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
788    
789     4. Some of the "internals" tests were previously cut out when the link size
790        was not 2, because the output contained actual offsets. The recent new
791        "Z" feature of pcretest means that these can be cut out, making the tests
792        usable with all link sizes.
793    
794     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
795        stack recursion. This gives a massive performance boost under BSD, but just
796        a small improvement under Linux. However, it saves one field in the frame
797        in all cases.
798    
799     6. Added more features from the forthcoming Perl 5.10:
800    
801        (a) (?-n) (where n is a string of digits) is a relative subroutine or
802            recursion call. It refers to the nth most recently opened parentheses.
803    
804        (b) (?+n) is also a relative subroutine call; it refers to the nth next
805            to be opened parentheses.
806    
807        (c) Conditions that refer to capturing parentheses can be specified
808            relatively, for example, (?(-2)... or (?(+3)...
809    
810        (d) \K resets the start of the current match so that everything before
811            is not part of it.
812    
813        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
814    
815        (f) \g{name} is another synonym - part of Perl 5.10's unification of
816            reference syntax.
817    
818        (g) (?| introduces a group in which the numbering of parentheses in each
819            alternative starts with the same number.
820    
821        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
822    
823     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
824        PCRE_INFO_JCHANGED.
825    
826     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
827        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
828        for detecting groups that can match an empty string.
829    
830     9. A pattern with a very large number of alternatives (more than several
831        hundred) was running out of internal workspace during the pre-compile
832        phase, where pcre_compile() figures out how much memory will be needed. A
833        bit of new cunning has reduced the workspace needed for groups with
834        alternatives. The 1000-alternative test pattern now uses 12 bytes of
835        workspace instead of running out of the 4096 that are available.
836    
837    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
838    
839    11. Applied patch from Google to remove an optimization that didn't quite work.
840        The report of the bug said:
841    
842          pcrecpp::RE("a*").FullMatch("aaa") matches, while
843          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
844          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
845    
846    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
847        it matched the wrong number of bytes.
848    
849    
850    Version 7.1 24-Apr-07
851    ---------------------
852    
853     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
854        that is more "standard", making use of automake and other Autotools. There
855        is some re-arrangement of the files and adjustment of comments consequent
856        on this.
857    
858     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
859        for recursive directory scanning broke on some systems because the files
860        are not scanned in any specific order and on different systems the order
861        was different. A call to "sort" has been inserted into RunGrepTest for the
862        approprate test as a short-term fix. In the longer term there may be an
863        alternative.
864    
865     3. I had an email from Eric Raymond about problems translating some of PCRE's
866        man pages to HTML (despite the fact that I distribute HTML pages, some
867        people do their own conversions for various reasons). The problems
868        concerned the use of low-level troff macros .br and .in. I have therefore
869        removed all such uses from the man pages (some were redundant, some could
870        be replaced by .nf/.fi pairs). The 132html script that I use to generate
871        HTML has been updated to handle .nf/.fi and to complain if it encounters
872        .br or .in.
873    
874     4. Updated comments in configure.ac that get placed in config.h.in and also
875        arranged for config.h to be included in the distribution, with the name
876        config.h.generic, for the benefit of those who have to compile without
877        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
878    
879     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
880        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
881        makevp.bat for the current PCRE, using the additional files
882        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
883    
884     6. A Windows user reported a minor discrepancy with test 2, which turned out
885        to be caused by a trailing space on an input line that had got lost in his
886        copy. The trailing space was an accident, so I've just removed it.
887    
888     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
889        that is needed.
890    
891     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
892        as "const" (a) because they are and (b) because it helps the PHP
893        maintainers who have recently made a script to detect big data structures
894        in the php code that should be moved to the .rodata section. I remembered
895        to update Builducptable as well, so it won't revert if ucptable.h is ever
896        re-created.
897    
898     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
899        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
900        order to be able to cut out the UTF-8 tables in the latter when UTF-8
901        support is not required. This saves 1.5-2K of code, which is important in
902        some applications.
903    
904        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
905        so as not to refer to the tables, even though these functions will never be
906        called when UTF-8 support is disabled. Otherwise there are problems with a
907        shared library.
908    
909    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
910    
911        (a) It was defining its arguments as char * instead of void *.
912    
913        (b) It was assuming that all moves were upwards in memory; this was true
914            a long time ago when I wrote it, but is no longer the case.
915    
916        The emulated memove() is provided for those environments that have neither
917        memmove() nor bcopy(). I didn't think anyone used it these days, but that
918        is clearly not the case, as these two bugs were recently reported.
919    
920    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
921        and Detrail to create the HTML documentation, the .txt form of the man
922        pages, and it removes trailing spaces from listed files. It also creates
923        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
924        case, it wraps all the #defines with #ifndefs. This script should be run
925        before "make dist".
926    
927    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
928        with Unicode property support.
929    
930        (a) For a maximizing quantifier, if the two different cases of the
931            character were of different lengths in their UTF-8 codings (there are
932            some cases like this - I found 11), and the matching function had to
933            back up over a mixture of the two cases, it incorrectly assumed they
934            were both the same length.
935    
936        (b) When PCRE was configured to use the heap rather than the stack for
937            recursion during matching, it was not correctly preserving the data for
938            the other case of a UTF-8 character when checking ahead for a match
939            while processing a minimizing repeat. If the check also involved
940            matching a wide character, but failed, corruption could cause an
941            erroneous result when trying to check for a repeat of the original
942            character.
943    
944    13. Some tidying changes to the testing mechanism:
945    
946        (a) The RunTest script now detects the internal link size and whether there
947            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
948            values substituted by "configure". (The RunGrepTest script already did
949            this for UTF-8.) The configure.ac script no longer substitutes the
950            relevant variables.
951    
952        (b) The debugging options /B and /D in pcretest show the compiled bytecode
953            with length and offset values. This means that the output is different
954            for different internal link sizes. Test 2 is skipped for link sizes
955            other than 2 because of this, bypassing the problem. Unfortunately,
956            there was also a test in test 3 (the locale tests) that used /B and
957            failed for link sizes other than 2. Rather than cut the whole test out,
958            I have added a new /Z option to pcretest that replaces the length and
959            offset values with spaces. This is now used to make test 3 independent
960            of link size. (Test 2 will be tidied up later.)
961    
962    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
963        segmentation fault instead of returning the appropriate error message.
964    
965    15. In multiline mode when the newline sequence was set to "any", the pattern
966        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
967        This doesn't seem right; it now treats the CRLF combination as the line
968        ending, and so does not match in that case. It's only a pattern such as ^$
969        that would hit this one: something like ^ABC$ would have failed after \r
970        and then tried again after \r\n.
971    
972    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
973        in an attempt to make files that differ only in their line terminators
974        compare equal. This works on Linux.
975    
976    17. Under certain error circumstances pcregrep might try to free random memory
977        as it exited. This is now fixed, thanks to valgrind.
978    
979    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
980        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
981        was because its rules for how to advance for /g after matching an empty
982        string at the end of a line did not allow for this case. They now check for
983        it specially.
984    
985    20. pcretest is supposed to handle patterns and data of any length, by
986        extending its buffers when necessary. It was getting this wrong when the
987        buffer for a data line had to be extended.
988    
989    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
990        CRLF as a newline sequence.
991    
992    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
993        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
994        I have nevertheless tidied it up.
995    
996    23. Added some casts to kill warnings from HP-UX ia64 compiler.
997    
998    24. Added a man page for pcre-config.
999    
1000    
1001    Version 7.0 19-Dec-06
1002    ---------------------
1003    
1004     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1005        moving to gcc 4.1.1.
1006    
1007     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1008        sys/time.h, which is documented as needed for this function. It doesn't
1009        seem to matter on Linux, but it showed up on some releases of OS X.
1010    
1011     3. It seems that there are systems where bytes whose values are greater than
1012        127 match isprint() in the "C" locale. The "C" locale should be the
1013        default when a C program starts up. In most systems, only ASCII printing
1014        characters match isprint(). This difference caused the output from pcretest
1015        to vary, making some of the tests fail. I have changed pcretest so that:
1016    
1017        (a) When it is outputting text in the compiled version of a pattern, bytes
1018            other than 32-126 are always shown as hex escapes.
1019    
1020        (b) When it is outputting text that is a matched part of a subject string,
1021            it does the same, unless a different locale has been set for the match
1022            (using the /L modifier). In this case, it uses isprint() to decide.
1023    
1024     4. Fixed a major bug that caused incorrect computation of the amount of memory
1025        required for a compiled pattern when options that changed within the
1026        pattern affected the logic of the preliminary scan that determines the
1027        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1028        that the computed length was too small. The symptoms of this bug were
1029        either the PCRE error "internal error: code overflow" from pcre_compile(),
1030        or a glibc crash with a message such as "pcretest: free(): invalid next
1031        size (fast)". Examples of patterns that provoked this bug (shown in
1032        pcretest format) are:
1033    
1034          /(?-x: )/x
1035          /(?x)(?-x: \s*#\s*)/
1036          /((?i)[\x{c0}])/8
1037          /(?i:[\x{c0}])/8
1038    
1039        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1040        is now done differently.
1041    
1042     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1043        wrapper classes; (b) implement a new function in the C++ scanner that is
1044        more efficient than the old way of doing things because it avoids levels of
1045        recursion in the regex matching; (c) add a paragraph to the documentation
1046        for the FullMatch() function.
1047    
1048     6. The escape sequence \n was being treated as whatever was defined as
1049        "newline". Not only was this contrary to the documentation, which states
1050        that \n is character 10 (hex 0A), but it also went horribly wrong when
1051        "newline" was defined as CRLF. This has been fixed.
1052    
1053     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1054        was being set to -1 for the "end of line" case (supposedly a value that no
1055        character can have). Though this value is never used (the check for end of
1056        line is "zero bytes in current character"), it caused compiler complaints.
1057        I've changed it to 0xffffffff.
1058    
1059     8. In pcre_version.c, the version string was being built by a sequence of
1060        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1061        string (as it is for production releases) called a macro with an empty
1062        argument. The C standard says the result of this is undefined. The gcc
1063        compiler treats it as an empty string (which was what was wanted) but it is
1064        reported that Visual C gives an error. The source has been hacked around to
1065        avoid this problem.
1066    
1067     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1068        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1069        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1070        of them did).
1071    
1072    10. Originally, pcretest opened its input and output without "b"; then I was
1073        told that "b" was needed in some environments, so it was added for release
1074        5.0 to both the input and output. (It makes no difference on Unix-like
1075        systems.) Later I was told that it is wrong for the input on Windows. I've
1076        now abstracted the modes into two macros, to make it easier to fiddle with
1077        them, and removed "b" from the input mode under Windows.
1078    
1079    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1080    
1081    12. Added -help and --help to pcretest as an official way of being reminded
1082        of the options.
1083    
1084    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1085        and pcrecpp.cc because they annoy compilers at high warning levels.
1086    
1087    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1088    
1089    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1090        scripts are not C programs :-) and which was not noticed because it works
1091        on Linux.
1092    
1093    16. pcretest is supposed to handle any length of pattern and data line (as one
1094        line or as a continued sequence of lines) by extending its input buffer if
1095        necessary. This feature was broken for very long pattern lines, leading to
1096        a string of junk being passed to pcre_compile() if the pattern was longer
1097        than about 50K.
1098    
1099    17. I have done a major re-factoring of the way pcre_compile() computes the
1100        amount of memory needed for a compiled pattern. Previously, there was code
1101        that made a preliminary scan of the pattern in order to do this. That was
1102        OK when PCRE was new, but as the facilities have expanded, it has become
1103        harder and harder to keep it in step with the real compile phase, and there
1104        have been a number of bugs (see for example, 4 above). I have now found a
1105        cunning way of running the real compile function in a "fake" mode that
1106        enables it to compute how much memory it would need, while actually only
1107        ever using a few hundred bytes of working memory and without too many
1108        tests of the mode. This should make future maintenance and development
1109        easier. A side effect of this work is that the limit of 200 on the nesting
1110        depth of parentheses has been removed (though this was never a serious
1111        limitation, I suspect). However, there is a downside: pcre_compile() now
1112        runs more slowly than before (30% or more, depending on the pattern). I
1113        hope this isn't a big issue. There is no effect on runtime performance.
1114    
1115    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1116        newline (only possible for the last line of a file) and it was a
1117        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1118    
1119    19. Added additional timing features to pcretest. (1) The -tm option now times
1120        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1121        separate command line item, by a number that specifies the number of
1122        repeats to use when timing. The default is 50000; this gives better
1123        precision, but takes uncomfortably long for very large patterns.
1124    
1125    20. Extended pcre_study() to be more clever in cases where a branch of a
1126        subpattern has no definite first character. For example, (a*|b*)[cd] would
1127        previously give no result from pcre_study(). Now it recognizes that the
1128        first character must be a, b, c, or d.
1129    
1130    21. There was an incorrect error "recursive call could loop indefinitely" if
1131        a subpattern (or the entire pattern) that was being tested for matching an
1132        empty string contained only one non-empty item after a nested subpattern.
1133        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1134        incorrectly, because the \d was being skipped in the check.
1135    
1136    22. The pcretest program now has a new pattern option /B and a command line
1137        option -b, which is equivalent to adding /B to every pattern. This causes
1138        it to show the compiled bytecode, without the additional information that
1139        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1140        is the same as /B/I).
1141    
1142    23. A new optimization is now able automatically to treat some sequences such
1143        as a*b as a*+b. More specifically, if something simple (such as a character
1144        or a simple class like \d) has an unlimited quantifier, and is followed by
1145        something that cannot possibly match the quantified thing, the quantifier
1146        is automatically "possessified".
1147    
1148    24. A recursive reference to a subpattern whose number was greater than 39
1149        went wrong under certain circumstances in UTF-8 mode. This bug could also
1150        have affected the operation of pcre_study().
1151    
1152    25. Realized that a little bit of performance could be had by replacing
1153        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1154    
1155    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1156    
1157    27. Possessive quantifiers such as a++ were previously implemented by turning
1158        them into atomic groups such as ($>a+). Now they have their own opcodes,
1159        which improves performance. This includes the automatically created ones
1160        from 23 above.
1161    
1162    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1163        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1164        the first matched character to be a colon. This applied both to named and
1165        numbered groups.
1166    
1167    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1168    
1169    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1170        building PCRE on Windows easier, so I have included it in the distribution.
1171    
1172    31. There is now a check in pcretest against a ridiculously large number being
1173        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1174        loop, the loop is abandoned.
1175    
1176    32. Forward references to subpatterns in conditions such as (?(2)...) where
1177        subpattern 2 is defined later cause pcre_compile() to search forwards in
1178        the pattern for the relevant set of parentheses. This search went wrong
1179        when there were unescaped parentheses in a character class, parentheses
1180        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1181    
1182    33. "Subroutine" calls and backreferences were previously restricted to
1183        referencing subpatterns earlier in the regex. This restriction has now
1184        been removed.
1185    
1186    34. Added a number of extra features that are going to be in Perl 5.10. On the
1187        whole, these are just syntactic alternatives for features that PCRE had
1188        previously implemented using the Python syntax or my own invention. The
1189        other formats are all retained for compatibility.
1190    
1191        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1192            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1193            also .NET compatible.
1194    
1195        (b) A recursion or subroutine call to a named group can now be defined as
1196            (?&name) as well as (?P>name).
1197    
1198        (c) A backreference to a named group can now be defined as \k<name> or
1199            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1200            5.10, are also .NET compatible.
1201    
1202        (d) A conditional reference to a named group can now use the syntax
1203            (?(<name>) or (?('name') as well as (?(name).
1204    
1205        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1206            groups (named and numbered) that are never evaluated inline, but can be
1207            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1208            is always false. There may be only one alternative in such a group.
1209    
1210        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1211            as the simple (?(R). The condition is true only if the most recent
1212            recursion is that of the given number or name. It does not search out
1213            through the entire recursion stack.
1214    
1215        (g) The escape \gN or \g{N} has been added, where N is a positive or
1216            negative number, specifying an absolute or relative reference.
1217    
1218    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1219        some "unreachable code" warnings.
1220    
1221    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1222        things, this adds five new scripts.
1223    
1224    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1225        There were also incompatibilities regarding the handling of \Q..\E inside
1226        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1227        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1228    
1229    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1230        matches an empty string, and forcibly breaks the loop. There were bugs in
1231        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1232        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1233        separate and independent bugs (that affected different cases) have been
1234        fixed.
1235    
1236    39. Refactored the code to abolish the use of different opcodes for small
1237        capturing bracket numbers. This is a tidy that I avoided doing when I
1238        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1239        The new approach is not only tidier, it makes it possible to reduce the
1240        memory needed to fix the previous bug (38).
1241    
1242    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1243        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1244        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1245        mode.
1246    
1247    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1248        report.
1249    
1250    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1251        copy construction and assignment in the C++ wrapper.
1252    
1253    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1254        couple of bugs that could have given wrong results in the "--newline=crlf"
1255        case.
1256    
1257    44. Added a number of casts and did some reorganization of signed/unsigned int
1258        variables following suggestions from Dair Grant. Also renamed the variable
1259        "this" as "item" because it is a C++ keyword.
1260    
1261    45. Arranged for dftables to add
1262    
1263          #include "pcre_internal.h"
1264    
1265        to pcre_chartables.c because without it, gcc 4.x may remove the array
1266        definition from the final binary if PCRE is built into a static library and
1267        dead code stripping is activated.
1268    
1269    46. For an unanchored pattern, if a match attempt fails at the start of a
1270        newline sequence, and the newline setting is CRLF or ANY, and the next two
1271        characters are CRLF, advance by two characters instead of one.
1272    
1273    
1274    Version 6.7 04-Jul-06
1275    ---------------------
1276    
1277     1. In order to handle tests when input lines are enormously long, pcretest has
1278        been re-factored so that it automatically extends its buffers when
1279        necessary. The code is crude, but this _is_ just a test program. The
1280        default size has been increased from 32K to 50K.
1281    
1282     2. The code in pcre_study() was using the value of the re argument before
1283        testing it for NULL. (Of course, in any sensible call of the function, it
1284        won't be NULL.)
1285    
1286     3. The memmove() emulation function in pcre_internal.h, which is used on
1287        systems that lack both memmove() and bcopy() - that is, hardly ever -
1288        was missing a "static" storage class specifier.
1289    
1290     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1291        containing an extended class (one that cannot be represented by a bitmap
1292        because it contains high-valued characters or Unicode property items, e.g.
1293        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1294        pattern, but PCRE should not loop if you do not (it no longer does).
1295        [Detail: two cases were found: (a) a repeated subpattern containing an
1296        extended class; (b) a recursive reference to a subpattern that followed a
1297        previous extended class. It wasn't skipping over the extended class
1298        correctly when UTF-8 mode was not set.]
1299    
1300     5. A negated single-character class was not being recognized as fixed-length
1301        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1302        compile error "lookbehind assertion is not fixed length".
1303    
1304     6. The RunPerlTest auxiliary script was showing an unexpected difference
1305        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1306        write a Perl script that can interpret lines of an input file either as
1307        byte characters or as UTF-8, which is what "perltest" was being required to
1308        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1309        can't do is switch easily at run time between having the "use utf8;" pragma
1310        or not. In the end, I fudged it by using the RunPerlTest script to insert
1311        "use utf8;" explicitly for the UTF-8 tests.
1312    
1313     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1314        the end of the subject string, contrary to the documentation and to what
1315        Perl does. This was true of both matching functions. Now it matches only at
1316        the start of the subject and immediately after *internal* newlines.
1317    
1318     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1319        a pointer to an int instead of a pointer to an unsigned long int. This
1320        caused problems on 64-bit systems.
1321    
1322     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1323        instance of the 'standard' template library not being so standard".
1324    
1325    10. There was no check on the number of named subpatterns nor the maximum
1326        length of a subpattern name. The product of these values is used to compute
1327        the size of the memory block for a compiled pattern. By supplying a very
1328        long subpattern name and a large number of named subpatterns, the size
1329        computation could be caused to overflow. This is now prevented by limiting
1330        the length of names to 32 characters, and the number of named subpatterns
1331        to 10,000.
1332    
1333    11. Subpatterns that are repeated with specific counts have to be replicated in
1334        the compiled pattern. The size of memory for this was computed from the
1335        length of the subpattern and the repeat count. The latter is limited to
1336        65535, but there was no limit on the former, meaning that integer overflow
1337        could in principle occur. The compiled length of a repeated subpattern is
1338        now limited to 30,000 bytes in order to prevent this.
1339    
1340    12. Added the optional facility to have named substrings with the same name.
1341    
1342    13. Added the ability to use a named substring as a condition, using the
1343        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1344        are numbers (not recommended). Forward references are permitted.
1345    
1346    14. Added forward references in named backreferences (if you see what I mean).
1347    
1348    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1349        pattern could run off the end of the subject. For example, the pattern
1350        "(?s)(.{1,5})"8 did this with the subject "ab".
1351    
1352    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1353        PCRE_CASELESS was set when matching characters that were quantified with ?
1354        or *.
1355    
1356    17. A character class other than a single negated character that had a minimum
1357        but no maximum quantifier - for example [ab]{6,} - was not handled
1358        correctly by pce_dfa_exec(). It would match only one character.
1359    
1360    18. A valid (though odd) pattern that looked like a POSIX character
1361        class but used an invalid character after [ (for example [[,abc,]]) caused
1362        pcre_compile() to give the error "Failed: internal error: code overflow" or
1363        in some cases to crash with a glibc free() error. This could even happen if
1364        the pattern terminated after [[ but there just happened to be a sequence of
1365        letters, a binary zero, and a closing ] in the memory that followed.
1366    
1367    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1368        over the years. Originally (before any Unicode support), just the bottom 8
1369        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1370        output from "man perlunicode" includes this:
1371    
1372          The regular expression compiler produces polymorphic opcodes.  That
1373          is, the pattern adapts to the data and automatically switches to
1374          the Unicode character scheme when presented with Unicode data--or
1375          instead uses a traditional byte scheme when presented with byte
1376          data.
1377    
1378        Sadly, a wide octal escape does not cause a switch, and in a string with
1379        no other multibyte characters, these octal escapes are treated as before.
1380        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1381        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1382        Unicode string.
1383    
1384        I have not perpetrated such confusion in PCRE. Up till now, it took just
1385        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1386        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1387        translate to the appropriate multibyte character.
1388    
1389    29. Applied some refactoring to reduce the number of warnings from Microsoft
1390        and Borland compilers. This has included removing the fudge introduced
1391        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1392        a warning about an unused variable.
1393    
1394    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1395        characters since release 4.0, because Perl (from release 5.004) does not.
1396        [Or at least, is documented not to: some releases seem to be in conflict
1397        with the documentation.] However, when a pattern was studied with
1398        pcre_study() and all its branches started with \s, PCRE still included VT
1399        as a possible starting character. Of course, this did no harm; it just
1400        caused an unnecessary match attempt.
1401    
1402    22. Removed a now-redundant internal flag bit that recorded the fact that case
1403        dependency changed within the pattern. This was once needed for "required
1404        byte" processing, but is no longer used. This recovers a now-scarce options
1405        bit. Also moved the least significant internal flag bit to the most-
1406        significant bit of the word, which was not previously used (hangover from
1407        the days when it was an int rather than a uint) to free up another bit for
1408        the future.
1409    
1410    23. Added support for CRLF line endings as well as CR and LF. As well as the
1411        default being selectable at build time, it can now be changed at runtime
1412        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1413        specify that it is scanning data with non-default line endings.
1414    
1415    24. Changed the definition of CXXLINK to make it agree with the definition of
1416        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1417    
1418    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1419        recursions. This makes a big different to stack usage for some patterns.
1420    
1421    26. If a subpattern containing a named recursion or subroutine reference such
1422        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1423        the space required for the compiled pattern went wrong and gave too small a
1424        value. Depending on the environment, this could lead to "Failed: internal
1425        error: code overflow at offset 49" or "glibc detected double free or
1426        corruption" errors.
1427    
1428    27. Applied patches from Google (a) to support the new newline modes and (b) to
1429        advance over multibyte UTF-8 characters in GlobalReplace.
1430    
1431    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1432        difference for some implementation of PCRE in some Windows version.
1433    
1434    29. Added some extra testing facilities to pcretest:
1435    
1436        \q<number>   in a data line sets the "match limit" value
1437        \Q<number>   in a data line sets the "match recursion limt" value
1438        -S <number>  sets the stack size, where <number> is in megabytes
1439    
1440        The -S option isn't available for Windows.
1441    
1442    
1443    Version 6.6 06-Feb-06
1444    ---------------------
1445    
1446     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1447        in pcreposix.h. I have copied the definition from pcre.h.
1448    
1449     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1450        because pcre.h is no longer a built file.
1451    
1452     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1453        not normally included in the compiled code.
1454    
1455    
1456    Version 6.5 01-Feb-06
1457    ---------------------
1458    
1459     1. When using the partial match feature with pcre_dfa_exec(), it was not
1460        anchoring the second and subsequent partial matches at the new starting
1461        point. This could lead to incorrect results. For example, with the pattern
1462        /1234/, partially matching against "123" and then "a4" gave a match.
1463    
1464     2. Changes to pcregrep:
1465    
1466        (a) All non-match returns from pcre_exec() were being treated as failures
1467            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1468            error message is output. Some extra information is given for the
1469            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1470            probably the only errors that are likely to be caused by users (by
1471            specifying a regex that has nested indefinite repeats, for instance).
1472            If there are more than 20 of these errors, pcregrep is abandoned.
1473    
1474        (b) A binary zero was treated as data while matching, but terminated the
1475            output line if it was written out. This has been fixed: binary zeroes
1476            are now no different to any other data bytes.
1477    
1478        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1479            used to set a locale for matching. The --locale=xxxx long option has
1480            been added (no short equivalent) to specify a locale explicitly on the
1481            pcregrep command, overriding the environment variables.
1482    
1483        (d) When -B was used with -n, some line numbers in the output were one less
1484            than they should have been.
1485    
1486        (e) Added the -o (--only-matching) option.
1487    
1488        (f) If -A or -C was used with -c (count only), some lines of context were
1489            accidentally printed for the final match.
1490    
1491        (g) Added the -H (--with-filename) option.
1492    
1493        (h) The combination of options -rh failed to suppress file names for files
1494            that were found from directory arguments.
1495    
1496        (i) Added the -D (--devices) and -d (--directories) options.
1497    
1498        (j) Added the -F (--fixed-strings) option.
1499    
1500        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1501    
1502        (l) Added the --colo(u)r option.
1503    
1504        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1505            is not present by default.
1506    
1507     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1508        items such as (?R) or (?1), when the recursion could match a number of
1509        alternatives. If it matched one of the alternatives, but subsequently,
1510        outside the recursion, there was a failure, the code tried to back up into
1511        the recursion. However, because of the way PCRE is implemented, this is not
1512        possible, and the result was an incorrect result from the match.
1513    
1514        In order to prevent this happening, the specification of recursion has
1515        been changed so that all such subpatterns are automatically treated as
1516        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1517    
1518     4. I had overlooked the fact that, in some locales, there are characters for
1519        which isalpha() is true but neither isupper() nor islower() are true. In
1520        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1521        and ordfeminine) are like this. This affected the treatment of \w and \W
1522        when they appeared in character classes, but not when they appeared outside
1523        a character class. The bit map for "word" characters is now created
1524        separately from the results of isalnum() instead of just taking it from the
1525        upper, lower, and digit maps. (Plus the underscore character, of course.)
1526    
1527     5. The above bug also affected the handling of POSIX character classes such as
1528        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1529        permanent tables. Instead, the bit maps for such a class were previously
1530        created as the appropriate unions of the upper, lower, and digit bitmaps.
1531        Now they are created by subtraction from the [[:word:]] class, which has
1532        its own bitmap.
1533    
1534     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1535        It is created by subtracting the vertical space characters (\x09, \x0a,
1536        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1537        subtraction was done in the overall bitmap for a character class, meaning
1538        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1539        be recognized. This bug has been fixed.
1540    
1541     7. Patches from the folks at Google:
1542    
1543          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1544          real life, but is still worth protecting against".
1545    
1546          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1547          regular expressions".
1548    
1549          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1550          have it.
1551    
1552          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1553          "configure" and the latter not, in order to fix a problem somebody had
1554          with compiling the Arg class on HP-UX.
1555    
1556          (e) Improve the error-handling of the C++ wrapper a little bit.
1557    
1558          (f) New tests for checking recursion limiting.
1559    
1560     8. The pcre_memmove() function, which is used only if the environment does not
1561        have a standard memmove() function (and is therefore rarely compiled),
1562        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1563        returning a result (though PCRE never actually uses the result).
1564    
1565     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1566        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1567        returned instead of calling malloc() with an overflowing number that would
1568        most likely cause subsequent chaos.
1569    
1570    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1571    
1572    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1573        with this option is matched, the nmatch and pmatch options of regexec() are
1574        ignored.
1575    
1576    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1577        provided in case anyone wants to the the POSIX interface with UTF-8
1578        strings.
1579    
1580    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1581        C++ linking (needed for some HP-UX environments).
1582    
1583    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1584        (unused parameter) and in the pcre_printint() function (omitted "default"
1585        switch label when the default is to do nothing).
1586    
1587    15. Added some code to make it possible, when PCRE is compiled as a C++
1588        library, to replace subject pointers for pcre_exec() with a smart pointer
1589        class, thus making it possible to process discontinuous strings.
1590    
1591    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1592        much the same function. They were added by different people who were trying
1593        to make PCRE easy to compile on non-Unix systems. It has been suggested
1594        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1595        for compiling on Windows systems. I have therefore replaced it with
1596        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1597        defaults to "extern" for C or "extern C" for C++, which works fine on
1598        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1599        SCOPE with something explicit in config.h. In addition:
1600    
1601        (a) pcreposix.h still had just "extern" instead of either of these macros;
1602            I have replaced it with PCRE_DATA_SCOPE.
1603    
1604        (b) Functions such as _pcre_xclass(), which are internal to the library,
1605            but external in the C sense, all had PCRE_EXPORT in their definitions.
1606            This is apparently wrong for the Windows case, so I have removed it.
1607            (It makes no difference on Unix-like systems.)
1608    
1609    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1610        of recursive calls to match(). This is different to MATCH_LIMIT because
1611        that limits the total number of calls to match(), not all of which increase
1612        the depth of recursion. Limiting the recursion depth limits the amount of
1613        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1614        when PCRE is compiled, and changed at run time. A patch from Google adds
1615        this functionality to the C++ interface.
1616    
1617    18. Changes to the handling of Unicode character properties:
1618    
1619        (a) Updated the table to Unicode 4.1.0.
1620    
1621        (b) Recognize characters that are not in the table as "Cn" (undefined).
1622    
1623        (c) I revised the way the table is implemented to a much improved format
1624            which includes recognition of ranges. It now supports the ranges that
1625            are defined in UnicodeData.txt, and it also amalgamates other
1626            characters into ranges. This has reduced the number of entries in the
1627            table from around 16,000 to around 3,000, thus reducing its size
1628            considerably. I realized I did not need to use a tree structure after
1629            all - a binary chop search is just as efficient. Having reduced the
1630            number of entries, I extended their size from 6 bytes to 8 bytes to
1631            allow for more data.
1632    
1633        (d) Added support for Unicode script names via properties such as \p{Han}.
1634    
1635    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1636        matching that character.
1637    
1638    20. When matching a repeated Unicode property with a minimum greater than zero,
1639        (for example \pL{2,}), PCRE could look past the end of the subject if it
1640        reached it while seeking the minimum number of characters. This could
1641        happen only if some of the characters were more than one byte long, because
1642        there is a check for at least the minimum number of bytes.
1643    
1644    21. Refactored the implementation of \p and \P so as to be more general, to
1645        allow for more different types of property in future. This has changed the
1646        compiled form incompatibly. Anybody with saved compiled patterns that use
1647        \p or \P will have to recompile them.
1648    
1649    22. Added "Any" and "L&" to the supported property types.
1650    
1651    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1652        but give a compile time error if the value is greater than 0xff.
1653    
1654    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1655        accidentally not being installed or uninstalled.
1656    
1657    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1658        made were to insert the current release number. This seemed silly, because
1659        it made things harder for people building PCRE on systems that don't run
1660        "configure". I have turned pcre.h into a distributed file, no longer built
1661        by "configure", with the version identification directly included. There is
1662        no longer a pcre.h.in file.
1663    
1664        However, this change necessitated a change to the pcre-config script as
1665        well. It is built from pcre-config.in, and one of the substitutions was the
1666        release number. I have updated configure.ac so that ./configure now finds
1667        the release number by grepping pcre.h.
1668    
1669    26. Added the ability to run the tests under valgrind.
1670    
1671    
1672    Version 6.4 05-Sep-05
1673    ---------------------
1674    
1675     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1676        "--" to be printed when multiple files were scanned, even when none of the
1677        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1678        consider it to be a bug, and have restored the previous behaviour.
1679    
1680     2. A couple of code tidies to get rid of compiler warnings.
1681    
1682     3. The pcretest program used to cheat by referring to symbols in the library
1683        whose names begin with _pcre_. These are internal symbols that are not
1684        really supposed to be visible externally, and in some environments it is
1685        possible to suppress them. The cheating is now confined to including
1686        certain files from the library's source, which is a bit cleaner.
1687    
1688     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1689        file's purpose clearer.
1690    
1691     5. Reorganized pcre_ucp_findchar().
1692    
1693    
1694    Version 6.3 15-Aug-05
1695    ---------------------
1696    
1697     1. The file libpcre.pc.in did not have general read permission in the tarball.
1698    
1699     2. There were some problems when building without C++ support:
1700    
1701        (a) If C++ support was not built, "make install" and "make test" still
1702            tried to test it.
1703    
1704        (b) There were problems when the value of CXX was explicitly set. Some
1705            changes have been made to try to fix these, and ...
1706    
1707        (c) --disable-cpp can now be used to explicitly disable C++ support.
1708    
1709        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1710            backslash in a target when C++ was disabled. This confuses some
1711            versions of "make", apparently. Using an intermediate variable solves
1712            this. (Same for CPP_LOBJ.)
1713    
1714     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1715        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1716        necessary on certain architectures.
1717    
1718     4. Added a setting of -export-symbols-regex to the link command to remove
1719        those symbols that are exported in the C sense, but actually are local
1720        within the library, and not documented. Their names all begin with
1721        "_pcre_". This is not a perfect job, because (a) we have to except some
1722        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1723        available (and never for static libraries). I have made a note to try to
1724        find a way round (a) in the future.
1725    
1726    
1727    Version 6.2 01-Aug-05
1728    ---------------------
1729    
1730     1. There was no test for integer overflow of quantifier values. A construction
1731        such as {1111111111111111} would give undefined results. What is worse, if
1732        a minimum quantifier for a parenthesized subpattern overflowed and became
1733        negative, the calculation of the memory size went wrong. This could have
1734        led to memory overwriting.
1735    
1736     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1737    
1738     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1739        operating environments where this matters.
1740    
1741     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1742        PCRE options from within the C++ wrapper.
1743    
1744     5. Named capturing subpatterns were not being correctly counted when a pattern
1745        was compiled. This caused two problems: (a) If there were more than 100
1746        such subpatterns, the calculation of the memory needed for the whole
1747        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1748        back references of the form \12, where the number was greater than 9, were
1749        not recognized as back references, even though there were sufficient
1750        previous subpatterns.
1751    
1752     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1753        versions of gcc, e.g. 2.95.4.
1754    
1755    
1756    Version 6.1 21-Jun-05
1757    ---------------------
1758    
1759     1. There was one reference to the variable "posix" in pcretest.c that was not
1760        surrounded by "#if !defined NOPOSIX".
1761    
1762     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1763        the cross-check on the old pcre_info() function, for the benefit of the
1764        cut-down version of PCRE that is currently imported into Exim.
1765    
1766     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1767        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1768        patterns that start (?i) but I don't think that matters. The use of (?i) is
1769        just an example; this all applies to the other options as well.
1770    
1771     4. Since libtool seems to echo the compile commands it is issuing, the output
1772        from "make" can be reduced a bit by putting "@" in front of each libtool
1773        compile command.
1774    
1775     5. Patch from the folks at Google for configure.in to be a bit more thorough
1776        in checking for a suitable C++ installation before trying to compile the
1777        C++ stuff. This should fix a reported problem when a compiler was present,
1778        but no suitable headers.
1779    
1780     6. The man pages all had just "PCRE" as their title. I have changed them to
1781        be the relevant file name. I have also arranged that these names are
1782        retained in the file doc/pcre.txt, which is a concatenation in text format
1783        of all the man pages except the little individual ones for each function.
1784    
1785     7. The NON-UNIX-USE file had not been updated for the different set of source
1786        files that come with release 6. I also added a few comments about the C++
1787        wrapper.
1788    
1789    
1790    Version 6.0 07-Jun-05
1791    ---------------------
1792    
1793     1. Some minor internal re-organization to help with my DFA experiments.
1794    
1795     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1796        didn't matter for the library itself when fully configured, but did matter
1797        when compiling without UCP support, or within Exim, where the ucp files are
1798        not imported.
1799    
1800     3. Refactoring of the library code to split up the various functions into
1801        different source modules. The addition of the new DFA matching code (see
1802        below) to a single monolithic source would have made it really too
1803        unwieldy, quite apart from causing all the code to be include in a
1804        statically linked application, when only some functions are used. This is
1805        relevant even without the DFA addition now that patterns can be compiled in
1806        one application and matched in another.
1807    
1808        The downside of splitting up is that there have to be some external
1809        functions and data tables that are used internally in different modules of
1810        the library but which are not part of the API. These have all had their
1811        names changed to start with "_pcre_" so that they are unlikely to clash
1812        with other external names.
1813    
1814     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1815        a different (DFA) algorithm. Although it is slower than the original
1816        function, it does have some advantages for certain types of matching
1817        problem.
1818    
1819     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1820        including restarting after a partial match.
1821    
1822     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1823        defined when compiling for Windows was sent to me. I have put it into the
1824        code, though I have no means of testing or verifying it.
1825    
1826     7. Added the pcre_refcount() auxiliary function.
1827    
1828     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1829        match before or at the first newline in the subject string. In pcretest,
1830        the /f option on a pattern can be used to set this.
1831    
1832     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1833        would behave wrongly. This has been present in PCRE since release 4.0.
1834    
1835    10. A number of changes to the pcregrep command:
1836    
1837        (a) Refactored how -x works; insert ^(...)$ instead of setting
1838            PCRE_ANCHORED and checking the length, in preparation for adding
1839            something similar for -w.
1840    
1841        (b) Added the -w (match as a word) option.
1842    
1843        (c) Refactored the way lines are read and buffered so as to have more
1844            than one at a time available.
1845    
1846        (d) Implemented a pcregrep test script.
1847    
1848        (e) Added the -M (multiline match) option. This allows patterns to match
1849            over several lines of the subject. The buffering ensures that at least
1850            8K, or the rest of the document (whichever is the shorter) is available
1851            for matching (and similarly the previous 8K for lookbehind assertions).
1852    
1853        (f) Changed the --help output so that it now says
1854    
1855              -w, --word-regex(p)
1856    
1857            instead of two lines, one with "regex" and the other with "regexp"
1858            because that confused at least one person since the short forms are the
1859            same. (This required a bit of code, as the output is generated
1860            automatically from a table. It wasn't just a text change.)
1861    
1862        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1863            option but starts with a hyphen. Could be a pattern or a path name
1864            starting with a hyphen, for instance.
1865    
1866        (h) "-" can be given as a file name to represent stdin.
1867    
1868        (i) When file names are being printed, "(standard input)" is used for
1869            the standard input, for compatibility with GNU grep. Previously
1870            "<stdin>" was used.
1871    
1872        (j) The option --label=xxx can be used to supply a name to be used for
1873            stdin when file names are being printed. There is no short form.
1874    
1875        (k) Re-factored the options decoding logic because we are going to add
1876            two more options that take data. Such options can now be given in four
1877            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1878    
1879        (l) Added the -A, -B, and -C options for requesting that lines of context
1880            around matches be printed.
1881    
1882        (m) Added the -L option to print the names of files that do not contain
1883            any matching lines, that is, the complement of -l.
1884    
1885        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1886            continue to scan other files.
1887    
1888        (o) The -s option was incorrectly implemented. For compatibility with other
1889            greps, it now suppresses the error message for a non-existent or non-
1890            accessible file (but not the return code). There is a new option called
1891            -q that suppresses the output of matching lines, which was what -s was
1892            previously doing.
1893    
1894        (p) Added --include and --exclude options to specify files for inclusion
1895            and exclusion when recursing.
1896    
1897    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1898        Hopefully, it now does.
1899    
1900    12. Missing cast in pcre_study().
1901    
1902    13. Added an "uninstall" target to the makefile.
1903    
1904    14. Replaced "extern" in the function prototypes in Makefile.in with
1905        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1906        world, but is set differently for Windows.
1907    
1908    15. Added a second compiling function called pcre_compile2(). The only
1909        difference is that it has an extra argument, which is a pointer to an
1910        integer error code. When there is a compile-time failure, this is set
1911        non-zero, in addition to the error test pointer being set to point to an
1912        error message. The new argument may be NULL if no error number is required
1913        (but then you may as well call pcre_compile(), which is now just a
1914        wrapper). This facility is provided because some applications need a
1915        numeric error indication, but it has also enabled me to tidy up the way
1916        compile-time errors are handled in the POSIX wrapper.
1917    
1918    16. Added VPATH=.libs to the makefile; this should help when building with one
1919        prefix path and installing with another. (Or so I'm told by someone who
1920        knows more about this stuff than I do.)
1921    
1922    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1923        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1924        match everything, including newlines. This is not POSIX-compatible, but
1925        somebody wanted the feature. From pcretest it can be activated by using
1926        both the P and the s flags.
1927    
1928    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1929    
1930    19. libpcre.pc was being incorrectly installed as executable.
1931    
1932    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1933        it now also looks for '\r' so that it will work unmodified on Windows.
1934    
1935    21. Added Google's contributed C++ wrapper to the distribution.
1936    
1937    22. Added some untidy missing memory free() calls in pcretest, to keep
1938        Electric Fence happy when testing.
1939    
1940    
1941    
1942    Version 5.0 13-Sep-04
1943    ---------------------
1944    
1945     1. Internal change: literal characters are no longer packed up into items
1946        containing multiple characters in a single byte-string. Each character
1947        is now matched using a separate opcode. However, there may be more than one
1948        byte in the character in UTF-8 mode.
1949    
1950     2. The pcre_callout_block structure has two new fields: pattern_position and
1951        next_item_length. These contain the offset in the pattern to the next match
1952        item, and its length, respectively.
1953    
1954     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1955        insertion of callouts before each pattern item. Added the /C option to
1956        pcretest to make use of this.
1957    
1958     4. On the advice of a Windows user, the lines
1959    
1960          #if defined(_WIN32) || defined(WIN32)
1961          _setmode( _fileno( stdout ), 0x8000 );
1962          #endif  /* defined(_WIN32) || defined(WIN32) */
1963    
1964        have been added to the source of pcretest. This apparently does useful
1965        magic in relation to line terminators.
1966    
1967     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1968        for the benefit of those environments where the "b" makes a difference.
1969    
1970     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1971        to know about it. I have put a hack into configure.in that adds in code
1972        to set GCC=yes if CC=icc. This seems to end up at a point in the
1973        generated configure script that is early enough to affect the setting of
1974        compiler options, which is what is needed, but I have no means of testing
1975        whether it really works. (The user who reported this had patched the
1976        generated configure script, which of course I cannot do.)
1977    
1978        LATER: After change 22 below (new libtool files), the configure script
1979        seems to know about icc (and also ecc). Therefore, I have commented out
1980        this hack in configure.in.
1981    
1982     7. Added support for pkg-config (2 patches were sent in).
1983    
1984     8. Negated POSIX character classes that used a combination of internal tables
1985        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1986        [[:^ascii]]. Typically, they would match almost any characters. The other
1987        POSIX classes were not broken in this way.
1988    
1989     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1990        to find the match, as PCRE was deluded into thinking that the match had to
1991        start at the start point or following a newline. The same bug applied to
1992        patterns with negative forward assertions or any backward assertions
1993        preceding ".*" at the start, unless the pattern required a fixed first
1994        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1995    
1996    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1997        starting at the last subject character, bytes beyond the end of the subject
1998        string were read.
1999    
2000    11. Renamed the variable "class" as "classbits" to make life easier for C++
2001        users. (Previously there was a macro definition, but it apparently wasn't
2002        enough.)
2003    
2004    12. Added the new field "tables" to the extra data so that tables can be passed
2005        in at exec time, or the internal tables can be re-selected. This allows
2006        a compiled regex to be saved and re-used at a later time by a different
2007        program that might have everything at different addresses.
2008    
2009    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2010        -R library as well as a -L library.
2011    
2012    14. The debugging options of pcretest (-d on the command line or D on a
2013        pattern) showed incorrect output for anything following an extended class
2014        that contained multibyte characters and which was followed by a quantifier.
2015    
2016    15. Added optional support for general category Unicode character properties
2017        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2018        support. It adds about 90K to the size of the library. The meanings of the
2019        inbuilt class escapes such as \d and \s have NOT been changed.
2020    
2021    16. Updated pcredemo.c to include calls to free() to release the memory for the
2022        compiled pattern.
2023    
2024    17. The generated file chartables.c was being created in the source directory
2025        instead of in the building directory. This caused the build to fail if the
2026        source directory was different from the building directory, and was
2027        read-only.
2028    
2029    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2030        file. No doubt somebody will tell me if they don't make sense... Also added
2031        Dan Mooney's comments about building on OpenVMS.
2032    
2033    19. Added support for partial matching via the PCRE_PARTIAL option for
2034        pcre_exec() and the \P data escape in pcretest.
2035    
2036    20. Extended pcretest with 3 new pattern features:
2037    
2038        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2039              write the compiled pattern to the file whose name is "rest-of-line".
2040              This is a straight binary dump of the data, with the saved pointer to
2041              the character tables forced to be NULL. The study data, if any, is
2042              written too. After writing, pcretest reads a new pattern.
2043    
2044        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2045              compiled pattern from the given file. There must not be any
2046              occurrences of "<" in the file name (pretty unlikely); if there are,
2047              pcretest will instead treat the initial "<" as a pattern delimiter.
2048              After reading in the pattern, pcretest goes on to read data lines as
2049              usual.
2050    
2051        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2052              and 16-bit fields in a compiled pattern, to simulate a pattern that
2053              was compiled on a host of opposite endianness.
2054    
2055    21. The pcre-exec() function can now cope with patterns that were compiled on
2056        hosts of opposite endianness, with this restriction:
2057    
2058          As for any compiled expression that is saved and used later, the tables
2059          pointer field cannot be preserved; the extra_data field in the arguments
2060          to pcre_exec() should be used to pass in a tables address if a value
2061          other than the default internal tables were used at compile time.
2062    
2063    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2064        now diagnosed as an error. Previously, most of the time, a negative number
2065        would have been treated as zero, but if in addition "ovector" was passed as
2066        NULL, a crash could occur.
2067    
2068    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2069        new versions from the libtool 1.5 distribution (the last one is a copy of
2070        a file called libtool.m4). This seems to have fixed the need to patch
2071        "configure" to support Darwin 1.3 (which I used to do). However, I still
2072        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2073        workstation).
2074    
2075    24. Changed the PCRE licence to be the more standard "BSD" licence.
2076    
2077    
2078    Version 4.5 01-Dec-03
2079    ---------------------
2080    
2081     1. There has been some re-arrangement of the code for the match() function so
2082        that it can be compiled in a version that does not call itself recursively.
2083        Instead, it keeps those local variables that need separate instances for
2084        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2085        needs to "recurse". Keeping track of where control must go is done by means
2086        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2087        hide most of the details from the main code, and operates only if
2088        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2089        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2090        operating.
2091    
2092        To make it easier for callers to provide specially tailored get/free
2093        functions for this usage, two new functions, pcre_stack_malloc, and
2094        pcre_stack_free, are used. They are always called in strict stacking order,
2095        and the size of block requested is always the same.
2096    
2097        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2098        PCRE has been compiled to use the stack or the heap for recursion. The
2099        -C option of pcretest uses this to show which version is compiled.
2100    
2101        A new data escape \S, is added to pcretest; it causes the amounts of store
2102        obtained and freed by both kinds of malloc/free at match time to be added
2103        to the output.
2104    
2105     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2106        what's available on my current Linux desktop machine.
2107    
2108     3. When matching a UTF-8 string, the test for a valid string at the start has
2109        been extended. If start_offset is not zero, PCRE now checks that it points
2110        to a byte that is the start of a UTF-8 character. If not, it returns
2111        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2112        this is necessary because there may be backward assertions in the pattern.
2113        When matching the same subject several times, it may save resources to use
2114        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2115    
2116     4. The code for checking the validity of UTF-8 strings has been tightened so
2117        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2118        containing "overlong sequences".
2119    
2120     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2121        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2122        should have been "&", but it just so happened that all the cases this let
2123        through by mistake were picked up later in the function.
2124    
2125     6. I had used a variable called "isblank" - this is a C99 function, causing
2126        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2127    
2128     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2129        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2130        so the version is shown; (c) stop "make test" echoing "./RunTest".
2131    
2132     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2133    
2134     9. The prototype for memmove() for systems that don't have it was using
2135        size_t, but the inclusion of the header that defines size_t was later. I've
2136        moved the #includes for the C headers earlier to avoid this.
2137    
2138    10. Added some adjustments to the code to make it easier to compiler on certain
2139        special systems:
2140    
2141          (a) Some "const" qualifiers were missing.
2142          (b) Added the macro EXPORT before all exported functions; by default this
2143              is defined to be empty.
2144          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2145              that it reads its output file name as an argument instead of writing
2146              to the standard output and assuming this can be redirected.
2147    
2148    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2149        class containing characters with values greater than 255, PCRE compilation
2150        went into a loop.
2151    
2152    12. A recursive reference to a subpattern that was within another subpattern
2153        that had a minimum quantifier of zero caused PCRE to crash. For example,
2154        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2155        recursion. If the recursively-called subpattern itself had a zero repeat,
2156        that was OK.
2157    
2158    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2159        buffer into which it was copied (for escape processing) was still set at
2160        1024, so long lines caused crashes.
2161    
2162    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2163        "internal error: code overflow...". This applied to any character class
2164        that was followed by a possessive quantifier.
2165    
2166    15. Modified the Makefile to add libpcre.la as a prerequisite for
2167        libpcreposix.la because I was told this is needed for a parallel build to
2168        work.
2169    
2170    16. If a pattern that contained .* following optional items at the start was
2171        studied, the wrong optimizing data was generated, leading to matching
2172        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2173        matching string must start with a or b or c. The correct conclusion for
2174        this pattern is that a match can start with any character.
2175    
2176    
2177    Version 4.4 13-Aug-03
2178    ---------------------
2179    
2180     1. In UTF-8 mode, a character class containing characters with values between
2181        127 and 255 was not handled correctly if the compiled pattern was studied.
2182        In fixing this, I have also improved the studying algorithm for such
2183        classes (slightly).
2184    
2185     2. Three internal functions had redundant arguments passed to them. Removal
2186        might give a very teeny performance improvement.
2187    
2188     3. Documentation bug: the value of the capture_top field in a callout is *one
2189        more than* the number of the hightest numbered captured substring.
2190    
2191     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2192        in incorrectly linking with a previously installed version. They now link
2193        explicitly with libpcre.la.
2194    
2195     5. configure.in no longer needs to recognize Cygwin specially.
2196    
2197     6. A problem in pcre.in for Windows platforms is fixed.
2198    
2199     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2200        pcretest, it used to include the size of the study block as part of its
2201        output. Unfortunately, the structure contains a field that has a different
2202        size on different hardware architectures. This meant that the tests that
2203        showed this size failed. As the block is currently always of a fixed size,
2204        this information isn't actually particularly useful in pcretest output, so
2205        I have just removed it.
2206    
2207     8. Three pre-processor statements accidentally did not start in column 1.
2208        Sadly, there are *still* compilers around that complain, even though
2209        standard C has not required this for well over a decade. Sigh.
2210    
2211     9. In pcretest, the code for checking callouts passed small integers in the
2212        callout_data field, which is a void * field. However, some picky compilers
2213        complained about the casts involved for this on 64-bit systems. Now
2214        pcretest passes the address of the small integer instead, which should get
2215        rid of the warnings.
2216    
2217    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2218        both compile and run time, and gives an error if an invalid UTF-8 sequence
2219        is found. There is a option for disabling this check in cases where the
2220        string is known to be correct and/or the maximum performance is wanted.
2221    
2222    11. In response to a bug report, I changed one line in Makefile.in from
2223    
2224            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2225        to
2226            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2227    
2228        to look similar to other lines, but I have no way of telling whether this
2229        is the right thing to do, as I do not use Windows. No doubt I'll get told
2230        if it's wrong...
2231    
2232    
2233  Version 4.3 21-May-03  Version 4.3 21-May-03
2234  ---------------------  ---------------------
2235    

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