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

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