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revision 71 by nigel, Sat Feb 24 21:40:24 2007 UTC revision 153 by ph10, Wed Apr 18 09:12:14 2007 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.1 12-Mar-07
5    ---------------------
6    
7     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
8        that is more "standard", making use of automake and other Autotools. There
9        is some re-arrangement of the files and adjustment of comments consequent
10        on this.
11    
12     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
13        for recursive directory scanning broke on some systems because the files
14        are not scanned in any specific order and on different systems the order
15        was different. A call to "sort" has been inserted into RunGrepTest for the
16        approprate test as a short-term fix. In the longer term there may be an
17        alternative.
18    
19     3. I had an email from Eric Raymond about problems translating some of PCRE's
20        man pages to HTML (despite the fact that I distribute HTML pages, some
21        people do their own conversions for various reasons). The problems
22        concerned the use of low-level troff macros .br and .in. I have therefore
23        removed all such uses from the man pages (some were redundant, some could
24        be replaced by .nf/.fi pairs). The 132html script that I use to generate
25        HTML has been updated to handle .nf/.fi and to complain if it encounters
26        .br or .in.
27    
28     4. Updated comments in configure.ac that get placed in config.h.in and also
29        arranged for config.h to be included in the distribution, with the name
30        config.h.generic, for the benefit of those who have to compile without
31        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
32    
33     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
34        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
35        makevp.bat for the current PCRE, using the additional files
36        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
37    
38     6. A Windows user reported a minor discrepancy with test 2, which turned out
39        to be caused by a trailing space on an input line that had got lost in his
40        copy. The trailing space was an accident, so I've just removed it.
41    
42     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
43        that is needed.
44    
45     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
46        as "const" (a) because they are and (b) because it helps the PHP
47        maintainers who have recently made a script to detect big data structures
48        in the php code that should be moved to the .rodata section. I remembered
49        to update Builducptable as well, so it won't revert if ucptable.h is ever
50        re-created.
51    
52     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
53        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
54        order to be able to cut out the UTF-8 tables in the latter when UTF-8
55        support is not required. This saves 1.5-2K of code, which is important in
56        some applications.
57    
58        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
59        so as not to refer to the tables, even though these functions will never be
60        called when UTF-8 support is disabled. Otherwise there are problems with a
61        shared library.
62    
63    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
64    
65        (a) It was defining its arguments as char * instead of void *.
66    
67        (b) It was assuming that all moves were upwards in memory; this was true
68            a long time ago when I wrote it, but is no longer the case.
69    
70        The emulated memove() is provided for those environments that have neither
71        memmove() nor bcopy(). I didn't think anyone used it these days, but that
72        is clearly not the case, as these two bugs were recently reported.
73    
74    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
75        and Detrail to create the HTML documentation, the .txt form of the man
76        pages, and it removes trailing spaces from listed files. It also creates
77        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
78        case, it wraps all the #defines with #ifndefs. This script should be run
79        before "make dist".
80    
81    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
82        with Unicode property support.
83    
84        (a) For a maximizing quantifier, if the two different cases of the
85            character were of different lengths in their UTF-8 codings (there are
86            some cases like this - I found 11), and the matching function had to
87            back up over a mixture of the two cases, it incorrectly assumed they
88            were both the same length.
89    
90        (b) When PCRE was configured to use the heap rather than the stack for
91            recursion during matching, it was not correctly preserving the data for
92            the other case of a UTF-8 character when checking ahead for a match
93            while processing a minimizing repeat. If the check also involved
94            matching a wide character, but failed, corruption could cause an
95            erroneous result when trying to check for a repeat of the original
96            character.
97    
98    13. Some tidying changes to the testing mechanism:
99    
100        (a) The RunTest script now detects the internal link size and whether there
101            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
102            values substituted by "configure". (The RunGrepTest script already did
103            this for UTF-8.) The configure.ac script no longer substitutes the
104            relevant variables.
105    
106        (b) The debugging options /B and /D in pcretest show the compiled bytecode
107            with length and offset values. This means that the output is different
108            for different internal link sizes. Test 2 is skipped for link sizes
109            other than 2 because of this, bypassing the problem. Unfortunately,
110            there was also a test in test 3 (the locale tests) that used /B and
111            failed for link sizes other than 2. Rather than cut the whole test out,
112            I have added a new /Z option to pcretest that replaces the length and
113            offset values with spaces. This is now used to make test 3 independent
114            of link size. (Test 2 will be tidied up later.)
115    
116    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
117        segmentation fault instead of returning the appropriate error message.
118    
119    15. In multiline mode when the newline sequence was set to "any", the pattern
120        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
121        This doesn't seem right; it now treats the CRLF combination as the line
122        ending, and so does not match in that case. It's only a pattern such as ^$
123        that would hit this one: something like ^ABC$ would have failed after \r
124        and then tried again after \r\n.
125    
126    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
127        in an attempt to make files that differ only in their line terminators
128        compare equal. This works on Linux.
129    
130    17. Under certain error circumstances pcregrep might try to free random memory
131        as it exited. This is now fixed, thanks to valgrind.
132    
133    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
134        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
135        was because its rules for how to advance for /g after matching an empty
136        string at the end of a line did not allow for this case. They now check for
137        it specially.
138    
139    20. pcretest is supposed to handle patterns and data of any length, by
140        extending its buffers when necessary. It was getting this wrong when the
141        buffer for a data line had to be extended.
142    
143    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
144        CRLF as a newline sequence.
145    
146    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
147        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
148        I have nevertheless tidied it up.
149    
150    23. Added some casts to kill warnings from HP-UX ia64 compiler.
151    
152    24. Added a man page for pcre-config.
153    
154    
155    Version 7.0 19-Dec-06
156    ---------------------
157    
158     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
159        moving to gcc 4.1.1.
160    
161     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
162        sys/time.h, which is documented as needed for this function. It doesn't
163        seem to matter on Linux, but it showed up on some releases of OS X.
164    
165     3. It seems that there are systems where bytes whose values are greater than
166        127 match isprint() in the "C" locale. The "C" locale should be the
167        default when a C program starts up. In most systems, only ASCII printing
168        characters match isprint(). This difference caused the output from pcretest
169        to vary, making some of the tests fail. I have changed pcretest so that:
170    
171        (a) When it is outputting text in the compiled version of a pattern, bytes
172            other than 32-126 are always shown as hex escapes.
173    
174        (b) When it is outputting text that is a matched part of a subject string,
175            it does the same, unless a different locale has been set for the match
176            (using the /L modifier). In this case, it uses isprint() to decide.
177    
178     4. Fixed a major bug that caused incorrect computation of the amount of memory
179        required for a compiled pattern when options that changed within the
180        pattern affected the logic of the preliminary scan that determines the
181        length. The relevant options are -x, and -i in UTF-8 mode. The result was
182        that the computed length was too small. The symptoms of this bug were
183        either the PCRE error "internal error: code overflow" from pcre_compile(),
184        or a glibc crash with a message such as "pcretest: free(): invalid next
185        size (fast)". Examples of patterns that provoked this bug (shown in
186        pcretest format) are:
187    
188          /(?-x: )/x
189          /(?x)(?-x: \s*#\s*)/
190          /((?i)[\x{c0}])/8
191          /(?i:[\x{c0}])/8
192    
193        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
194        is now done differently.
195    
196     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
197        wrapper classes; (b) implement a new function in the C++ scanner that is
198        more efficient than the old way of doing things because it avoids levels of
199        recursion in the regex matching; (c) add a paragraph to the documentation
200        for the FullMatch() function.
201    
202     6. The escape sequence \n was being treated as whatever was defined as
203        "newline". Not only was this contrary to the documentation, which states
204        that \n is character 10 (hex 0A), but it also went horribly wrong when
205        "newline" was defined as CRLF. This has been fixed.
206    
207     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
208        was being set to -1 for the "end of line" case (supposedly a value that no
209        character can have). Though this value is never used (the check for end of
210        line is "zero bytes in current character"), it caused compiler complaints.
211        I've changed it to 0xffffffff.
212    
213     8. In pcre_version.c, the version string was being built by a sequence of
214        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
215        string (as it is for production releases) called a macro with an empty
216        argument. The C standard says the result of this is undefined. The gcc
217        compiler treats it as an empty string (which was what was wanted) but it is
218        reported that Visual C gives an error. The source has been hacked around to
219        avoid this problem.
220    
221     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
222        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
223        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
224        of them did).
225    
226    10. Originally, pcretest opened its input and output without "b"; then I was
227        told that "b" was needed in some environments, so it was added for release
228        5.0 to both the input and output. (It makes no difference on Unix-like
229        systems.) Later I was told that it is wrong for the input on Windows. I've
230        now abstracted the modes into two macros, to make it easier to fiddle with
231        them, and removed "b" from the input mode under Windows.
232    
233    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
234    
235    12. Added -help and --help to pcretest as an official way of being reminded
236        of the options.
237    
238    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
239        and pcrecpp.cc because they annoy compilers at high warning levels.
240    
241    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
242    
243    15. Fixed an occurrence of == in configure.ac that should have been = (shell
244        scripts are not C programs :-) and which was not noticed because it works
245        on Linux.
246    
247    16. pcretest is supposed to handle any length of pattern and data line (as one
248        line or as a continued sequence of lines) by extending its input buffer if
249        necessary. This feature was broken for very long pattern lines, leading to
250        a string of junk being passed to pcre_compile() if the pattern was longer
251        than about 50K.
252    
253    17. I have done a major re-factoring of the way pcre_compile() computes the
254        amount of memory needed for a compiled pattern. Previously, there was code
255        that made a preliminary scan of the pattern in order to do this. That was
256        OK when PCRE was new, but as the facilities have expanded, it has become
257        harder and harder to keep it in step with the real compile phase, and there
258        have been a number of bugs (see for example, 4 above). I have now found a
259        cunning way of running the real compile function in a "fake" mode that
260        enables it to compute how much memory it would need, while actually only
261        ever using a few hundred bytes of working memory and without too many
262        tests of the mode. This should make future maintenance and development
263        easier. A side effect of this work is that the limit of 200 on the nesting
264        depth of parentheses has been removed (though this was never a serious
265        limitation, I suspect). However, there is a downside: pcre_compile() now
266        runs more slowly than before (30% or more, depending on the pattern). I
267        hope this isn't a big issue. There is no effect on runtime performance.
268    
269    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
270        newline (only possible for the last line of a file) and it was a
271        pattern that set a locale (followed by /Lsomething), pcretest crashed.
272    
273    19. Added additional timing features to pcretest. (1) The -tm option now times
274        matching only, not compiling. (2) Both -t and -tm can be followed, as a
275        separate command line item, by a number that specifies the number of
276        repeats to use when timing. The default is 50000; this gives better
277        precision, but takes uncomfortably long for very large patterns.
278    
279    20. Extended pcre_study() to be more clever in cases where a branch of a
280        subpattern has no definite first character. For example, (a*|b*)[cd] would
281        previously give no result from pcre_study(). Now it recognizes that the
282        first character must be a, b, c, or d.
283    
284    21. There was an incorrect error "recursive call could loop indefinitely" if
285        a subpattern (or the entire pattern) that was being tested for matching an
286        empty string contained only one non-empty item after a nested subpattern.
287        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
288        incorrectly, because the \d was being skipped in the check.
289    
290    22. The pcretest program now has a new pattern option /B and a command line
291        option -b, which is equivalent to adding /B to every pattern. This causes
292        it to show the compiled bytecode, without the additional information that
293        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
294        is the same as /B/I).
295    
296    23. A new optimization is now able automatically to treat some sequences such
297        as a*b as a*+b. More specifically, if something simple (such as a character
298        or a simple class like \d) has an unlimited quantifier, and is followed by
299        something that cannot possibly match the quantified thing, the quantifier
300        is automatically "possessified".
301    
302    24. A recursive reference to a subpattern whose number was greater than 39
303        went wrong under certain circumstances in UTF-8 mode. This bug could also
304        have affected the operation of pcre_study().
305    
306    25. Realized that a little bit of performance could be had by replacing
307        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
308    
309    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
310    
311    27. Possessive quantifiers such as a++ were previously implemented by turning
312        them into atomic groups such as ($>a+). Now they have their own opcodes,
313        which improves performance. This includes the automatically created ones
314        from 23 above.
315    
316    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
317        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
318        the first matched character to be a colon. This applied both to named and
319        numbered groups.
320    
321    29. The ucpinternal.h header file was missing its idempotency #ifdef.
322    
323    30. I was sent a "project" file called libpcre.a.dev which I understand makes
324        building PCRE on Windows easier, so I have included it in the distribution.
325    
326    31. There is now a check in pcretest against a ridiculously large number being
327        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
328        loop, the loop is abandoned.
329    
330    32. Forward references to subpatterns in conditions such as (?(2)...) where
331        subpattern 2 is defined later cause pcre_compile() to search forwards in
332        the pattern for the relevant set of parentheses. This search went wrong
333        when there were unescaped parentheses in a character class, parentheses
334        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
335    
336    33. "Subroutine" calls and backreferences were previously restricted to
337        referencing subpatterns earlier in the regex. This restriction has now
338        been removed.
339    
340    34. Added a number of extra features that are going to be in Perl 5.10. On the
341        whole, these are just syntactic alternatives for features that PCRE had
342        previously implemented using the Python syntax or my own invention. The
343        other formats are all retained for compatibility.
344    
345        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
346            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
347            also .NET compatible.
348    
349        (b) A recursion or subroutine call to a named group can now be defined as
350            (?&name) as well as (?P>name).
351    
352        (c) A backreference to a named group can now be defined as \k<name> or
353            \k'name' as well as (?P=name). The new forms, as well as being in Perl
354            5.10, are also .NET compatible.
355    
356        (d) A conditional reference to a named group can now use the syntax
357            (?(<name>) or (?('name') as well as (?(name).
358    
359        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
360            groups (named and numbered) that are never evaluated inline, but can be
361            called as "subroutines" from elsewhere. In effect, the DEFINE condition
362            is always false. There may be only one alternative in such a group.
363    
364        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
365            as the simple (?(R). The condition is true only if the most recent
366            recursion is that of the given number or name. It does not search out
367            through the entire recursion stack.
368    
369        (g) The escape \gN or \g{N} has been added, where N is a positive or
370            negative number, specifying an absolute or relative reference.
371    
372    35. Tidied to get rid of some further signed/unsigned compiler warnings and
373        some "unreachable code" warnings.
374    
375    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
376        things, this adds five new scripts.
377    
378    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
379        There were also incompatibilities regarding the handling of \Q..\E inside
380        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
381        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
382    
383    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
384        matches an empty string, and forcibly breaks the loop. There were bugs in
385        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
386        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
387        separate and independent bugs (that affected different cases) have been
388        fixed.
389    
390    39. Refactored the code to abolish the use of different opcodes for small
391        capturing bracket numbers. This is a tidy that I avoided doing when I
392        removed the limit on the number of capturing brackets for 3.5 back in 2001.
393        The new approach is not only tidier, it makes it possible to reduce the
394        memory needed to fix the previous bug (38).
395    
396    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
397        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
398        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
399        mode.
400    
401    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
402        report.
403    
404    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
405        copy construction and assignment in the C++ wrapper.
406    
407    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
408        couple of bugs that could have given wrong results in the "--newline=crlf"
409        case.
410    
411    44. Added a number of casts and did some reorganization of signed/unsigned int
412        variables following suggestions from Dair Grant. Also renamed the variable
413        "this" as "item" because it is a C++ keyword.
414    
415    45. Arranged for dftables to add
416    
417          #include "pcre_internal.h"
418    
419        to pcre_chartables.c because without it, gcc 4.x may remove the array
420        definition from the final binary if PCRE is built into a static library and
421        dead code stripping is activated.
422    
423    46. For an unanchored pattern, if a match attempt fails at the start of a
424        newline sequence, and the newline setting is CRLF or ANY, and the next two
425        characters are CRLF, advance by two characters instead of one.
426    
427    
428    Version 6.7 04-Jul-06
429    ---------------------
430    
431     1. In order to handle tests when input lines are enormously long, pcretest has
432        been re-factored so that it automatically extends its buffers when
433        necessary. The code is crude, but this _is_ just a test program. The
434        default size has been increased from 32K to 50K.
435    
436     2. The code in pcre_study() was using the value of the re argument before
437        testing it for NULL. (Of course, in any sensible call of the function, it
438        won't be NULL.)
439    
440     3. The memmove() emulation function in pcre_internal.h, which is used on
441        systems that lack both memmove() and bcopy() - that is, hardly ever -
442        was missing a "static" storage class specifier.
443    
444     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
445        containing an extended class (one that cannot be represented by a bitmap
446        because it contains high-valued characters or Unicode property items, e.g.
447        [\pZ]). Almost always one would set UTF-8 mode when processing such a
448        pattern, but PCRE should not loop if you do not (it no longer does).
449        [Detail: two cases were found: (a) a repeated subpattern containing an
450        extended class; (b) a recursive reference to a subpattern that followed a
451        previous extended class. It wasn't skipping over the extended class
452        correctly when UTF-8 mode was not set.]
453    
454     5. A negated single-character class was not being recognized as fixed-length
455        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
456        compile error "lookbehind assertion is not fixed length".
457    
458     6. The RunPerlTest auxiliary script was showing an unexpected difference
459        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
460        write a Perl script that can interpret lines of an input file either as
461        byte characters or as UTF-8, which is what "perltest" was being required to
462        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
463        can't do is switch easily at run time between having the "use utf8;" pragma
464        or not. In the end, I fudged it by using the RunPerlTest script to insert
465        "use utf8;" explicitly for the UTF-8 tests.
466    
467     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
468        the end of the subject string, contrary to the documentation and to what
469        Perl does. This was true of both matching functions. Now it matches only at
470        the start of the subject and immediately after *internal* newlines.
471    
472     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
473        a pointer to an int instead of a pointer to an unsigned long int. This
474        caused problems on 64-bit systems.
475    
476     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
477        instance of the 'standard' template library not being so standard".
478    
479    10. There was no check on the number of named subpatterns nor the maximum
480        length of a subpattern name. The product of these values is used to compute
481        the size of the memory block for a compiled pattern. By supplying a very
482        long subpattern name and a large number of named subpatterns, the size
483        computation could be caused to overflow. This is now prevented by limiting
484        the length of names to 32 characters, and the number of named subpatterns
485        to 10,000.
486    
487    11. Subpatterns that are repeated with specific counts have to be replicated in
488        the compiled pattern. The size of memory for this was computed from the
489        length of the subpattern and the repeat count. The latter is limited to
490        65535, but there was no limit on the former, meaning that integer overflow
491        could in principle occur. The compiled length of a repeated subpattern is
492        now limited to 30,000 bytes in order to prevent this.
493    
494    12. Added the optional facility to have named substrings with the same name.
495    
496    13. Added the ability to use a named substring as a condition, using the
497        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
498        are numbers (not recommended). Forward references are permitted.
499    
500    14. Added forward references in named backreferences (if you see what I mean).
501    
502    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
503        pattern could run off the end of the subject. For example, the pattern
504        "(?s)(.{1,5})"8 did this with the subject "ab".
505    
506    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
507        PCRE_CASELESS was set when matching characters that were quantified with ?
508        or *.
509    
510    17. A character class other than a single negated character that had a minimum
511        but no maximum quantifier - for example [ab]{6,} - was not handled
512        correctly by pce_dfa_exec(). It would match only one character.
513    
514    18. A valid (though odd) pattern that looked like a POSIX character
515        class but used an invalid character after [ (for example [[,abc,]]) caused
516        pcre_compile() to give the error "Failed: internal error: code overflow" or
517        in some cases to crash with a glibc free() error. This could even happen if
518        the pattern terminated after [[ but there just happened to be a sequence of
519        letters, a binary zero, and a closing ] in the memory that followed.
520    
521    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
522        over the years. Originally (before any Unicode support), just the bottom 8
523        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
524        output from "man perlunicode" includes this:
525    
526          The regular expression compiler produces polymorphic opcodes.  That
527          is, the pattern adapts to the data and automatically switches to
528          the Unicode character scheme when presented with Unicode data--or
529          instead uses a traditional byte scheme when presented with byte
530          data.
531    
532        Sadly, a wide octal escape does not cause a switch, and in a string with
533        no other multibyte characters, these octal escapes are treated as before.
534        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
535        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
536        Unicode string.
537    
538        I have not perpetrated such confusion in PCRE. Up till now, it took just
539        the bottom 8 bits, as in old Perl. I have now made octal escapes with
540        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
541        translate to the appropriate multibyte character.
542    
543    29. Applied some refactoring to reduce the number of warnings from Microsoft
544        and Borland compilers. This has included removing the fudge introduced
545        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
546        a warning about an unused variable.
547    
548    21. PCRE has not included VT (character 0x0b) in the set of whitespace
549        characters since release 4.0, because Perl (from release 5.004) does not.
550        [Or at least, is documented not to: some releases seem to be in conflict
551        with the documentation.] However, when a pattern was studied with
552        pcre_study() and all its branches started with \s, PCRE still included VT
553        as a possible starting character. Of course, this did no harm; it just
554        caused an unnecessary match attempt.
555    
556    22. Removed a now-redundant internal flag bit that recorded the fact that case
557        dependency changed within the pattern. This was once needed for "required
558        byte" processing, but is no longer used. This recovers a now-scarce options
559        bit. Also moved the least significant internal flag bit to the most-
560        significant bit of the word, which was not previously used (hangover from
561        the days when it was an int rather than a uint) to free up another bit for
562        the future.
563    
564    23. Added support for CRLF line endings as well as CR and LF. As well as the
565        default being selectable at build time, it can now be changed at runtime
566        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
567        specify that it is scanning data with non-default line endings.
568    
569    24. Changed the definition of CXXLINK to make it agree with the definition of
570        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
571    
572    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
573        recursions. This makes a big different to stack usage for some patterns.
574    
575    26. If a subpattern containing a named recursion or subroutine reference such
576        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
577        the space required for the compiled pattern went wrong and gave too small a
578        value. Depending on the environment, this could lead to "Failed: internal
579        error: code overflow at offset 49" or "glibc detected double free or
580        corruption" errors.
581    
582    27. Applied patches from Google (a) to support the new newline modes and (b) to
583        advance over multibyte UTF-8 characters in GlobalReplace.
584    
585    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
586        difference for some implementation of PCRE in some Windows version.
587    
588    29. Added some extra testing facilities to pcretest:
589    
590        \q<number>   in a data line sets the "match limit" value
591        \Q<number>   in a data line sets the "match recursion limt" value
592        -S <number>  sets the stack size, where <number> is in megabytes
593    
594        The -S option isn't available for Windows.
595    
596    
597    Version 6.6 06-Feb-06
598    ---------------------
599    
600     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
601        in pcreposix.h. I have copied the definition from pcre.h.
602    
603     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
604        because pcre.h is no longer a built file.
605    
606     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
607        not normally included in the compiled code.
608    
609    
610    Version 6.5 01-Feb-06
611    ---------------------
612    
613     1. When using the partial match feature with pcre_dfa_exec(), it was not
614        anchoring the second and subsequent partial matches at the new starting
615        point. This could lead to incorrect results. For example, with the pattern
616        /1234/, partially matching against "123" and then "a4" gave a match.
617    
618     2. Changes to pcregrep:
619    
620        (a) All non-match returns from pcre_exec() were being treated as failures
621            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
622            error message is output. Some extra information is given for the
623            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
624            probably the only errors that are likely to be caused by users (by
625            specifying a regex that has nested indefinite repeats, for instance).
626            If there are more than 20 of these errors, pcregrep is abandoned.
627    
628        (b) A binary zero was treated as data while matching, but terminated the
629            output line if it was written out. This has been fixed: binary zeroes
630            are now no different to any other data bytes.
631    
632        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
633            used to set a locale for matching. The --locale=xxxx long option has
634            been added (no short equivalent) to specify a locale explicitly on the
635            pcregrep command, overriding the environment variables.
636    
637        (d) When -B was used with -n, some line numbers in the output were one less
638            than they should have been.
639    
640        (e) Added the -o (--only-matching) option.
641    
642        (f) If -A or -C was used with -c (count only), some lines of context were
643            accidentally printed for the final match.
644    
645        (g) Added the -H (--with-filename) option.
646    
647        (h) The combination of options -rh failed to suppress file names for files
648            that were found from directory arguments.
649    
650        (i) Added the -D (--devices) and -d (--directories) options.
651    
652        (j) Added the -F (--fixed-strings) option.
653    
654        (k) Allow "-" to be used as a file name for -f as well as for a data file.
655    
656        (l) Added the --colo(u)r option.
657    
658        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
659            is not present by default.
660    
661     3. A nasty bug was discovered in the handling of recursive patterns, that is,
662        items such as (?R) or (?1), when the recursion could match a number of
663        alternatives. If it matched one of the alternatives, but subsequently,
664        outside the recursion, there was a failure, the code tried to back up into
665        the recursion. However, because of the way PCRE is implemented, this is not
666        possible, and the result was an incorrect result from the match.
667    
668        In order to prevent this happening, the specification of recursion has
669        been changed so that all such subpatterns are automatically treated as
670        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
671    
672     4. I had overlooked the fact that, in some locales, there are characters for
673        which isalpha() is true but neither isupper() nor islower() are true. In
674        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
675        and ordfeminine) are like this. This affected the treatment of \w and \W
676        when they appeared in character classes, but not when they appeared outside
677        a character class. The bit map for "word" characters is now created
678        separately from the results of isalnum() instead of just taking it from the
679        upper, lower, and digit maps. (Plus the underscore character, of course.)
680    
681     5. The above bug also affected the handling of POSIX character classes such as
682        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
683        permanent tables. Instead, the bit maps for such a class were previously
684        created as the appropriate unions of the upper, lower, and digit bitmaps.
685        Now they are created by subtraction from the [[:word:]] class, which has
686        its own bitmap.
687    
688     6. The [[:blank:]] character class matches horizontal, but not vertical space.
689        It is created by subtracting the vertical space characters (\x09, \x0a,
690        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
691        subtraction was done in the overall bitmap for a character class, meaning
692        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
693        be recognized. This bug has been fixed.
694    
695     7. Patches from the folks at Google:
696    
697          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
698          real life, but is still worth protecting against".
699    
700          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
701          regular expressions".
702    
703          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
704          have it.
705    
706          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
707          "configure" and the latter not, in order to fix a problem somebody had
708          with compiling the Arg class on HP-UX.
709    
710          (e) Improve the error-handling of the C++ wrapper a little bit.
711    
712          (f) New tests for checking recursion limiting.
713    
714     8. The pcre_memmove() function, which is used only if the environment does not
715        have a standard memmove() function (and is therefore rarely compiled),
716        contained two bugs: (a) use of int instead of size_t, and (b) it was not
717        returning a result (though PCRE never actually uses the result).
718    
719     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
720        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
721        returned instead of calling malloc() with an overflowing number that would
722        most likely cause subsequent chaos.
723    
724    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
725    
726    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
727        with this option is matched, the nmatch and pmatch options of regexec() are
728        ignored.
729    
730    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
731        provided in case anyone wants to the the POSIX interface with UTF-8
732        strings.
733    
734    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
735        C++ linking (needed for some HP-UX environments).
736    
737    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
738        (unused parameter) and in the pcre_printint() function (omitted "default"
739        switch label when the default is to do nothing).
740    
741    15. Added some code to make it possible, when PCRE is compiled as a C++
742        library, to replace subject pointers for pcre_exec() with a smart pointer
743        class, thus making it possible to process discontinuous strings.
744    
745    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
746        much the same function. They were added by different people who were trying
747        to make PCRE easy to compile on non-Unix systems. It has been suggested
748        that PCRE_EXPORT be abolished now that there is more automatic apparatus
749        for compiling on Windows systems. I have therefore replaced it with
750        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
751        defaults to "extern" for C or "extern C" for C++, which works fine on
752        Unix-like systems. It is now possible to override the value of PCRE_DATA_
753        SCOPE with something explicit in config.h. In addition:
754    
755        (a) pcreposix.h still had just "extern" instead of either of these macros;
756            I have replaced it with PCRE_DATA_SCOPE.
757    
758        (b) Functions such as _pcre_xclass(), which are internal to the library,
759            but external in the C sense, all had PCRE_EXPORT in their definitions.
760            This is apparently wrong for the Windows case, so I have removed it.
761            (It makes no difference on Unix-like systems.)
762    
763    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
764        of recursive calls to match(). This is different to MATCH_LIMIT because
765        that limits the total number of calls to match(), not all of which increase
766        the depth of recursion. Limiting the recursion depth limits the amount of
767        stack (or heap if NO_RECURSE is set) that is used. The default can be set
768        when PCRE is compiled, and changed at run time. A patch from Google adds
769        this functionality to the C++ interface.
770    
771    18. Changes to the handling of Unicode character properties:
772    
773        (a) Updated the table to Unicode 4.1.0.
774    
775        (b) Recognize characters that are not in the table as "Cn" (undefined).
776    
777        (c) I revised the way the table is implemented to a much improved format
778            which includes recognition of ranges. It now supports the ranges that
779            are defined in UnicodeData.txt, and it also amalgamates other
780            characters into ranges. This has reduced the number of entries in the
781            table from around 16,000 to around 3,000, thus reducing its size
782            considerably. I realized I did not need to use a tree structure after
783            all - a binary chop search is just as efficient. Having reduced the
784            number of entries, I extended their size from 6 bytes to 8 bytes to
785            allow for more data.
786    
787        (d) Added support for Unicode script names via properties such as \p{Han}.
788    
789    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
790        matching that character.
791    
792    20. When matching a repeated Unicode property with a minimum greater than zero,
793        (for example \pL{2,}), PCRE could look past the end of the subject if it
794        reached it while seeking the minimum number of characters. This could
795        happen only if some of the characters were more than one byte long, because
796        there is a check for at least the minimum number of bytes.
797    
798    21. Refactored the implementation of \p and \P so as to be more general, to
799        allow for more different types of property in future. This has changed the
800        compiled form incompatibly. Anybody with saved compiled patterns that use
801        \p or \P will have to recompile them.
802    
803    22. Added "Any" and "L&" to the supported property types.
804    
805    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
806        but give a compile time error if the value is greater than 0xff.
807    
808    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
809        accidentally not being installed or uninstalled.
810    
811    25. The pcre.h file was built from pcre.h.in, but the only changes that were
812        made were to insert the current release number. This seemed silly, because
813        it made things harder for people building PCRE on systems that don't run
814        "configure". I have turned pcre.h into a distributed file, no longer built
815        by "configure", with the version identification directly included. There is
816        no longer a pcre.h.in file.
817    
818        However, this change necessitated a change to the pcre-config script as
819        well. It is built from pcre-config.in, and one of the substitutions was the
820        release number. I have updated configure.ac so that ./configure now finds
821        the release number by grepping pcre.h.
822    
823    26. Added the ability to run the tests under valgrind.
824    
825    
826    Version 6.4 05-Sep-05
827    ---------------------
828    
829     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
830        "--" to be printed when multiple files were scanned, even when none of the
831        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
832        consider it to be a bug, and have restored the previous behaviour.
833    
834     2. A couple of code tidies to get rid of compiler warnings.
835    
836     3. The pcretest program used to cheat by referring to symbols in the library
837        whose names begin with _pcre_. These are internal symbols that are not
838        really supposed to be visible externally, and in some environments it is
839        possible to suppress them. The cheating is now confined to including
840        certain files from the library's source, which is a bit cleaner.
841    
842     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
843        file's purpose clearer.
844    
845     5. Reorganized pcre_ucp_findchar().
846    
847    
848    Version 6.3 15-Aug-05
849    ---------------------
850    
851     1. The file libpcre.pc.in did not have general read permission in the tarball.
852    
853     2. There were some problems when building without C++ support:
854    
855        (a) If C++ support was not built, "make install" and "make test" still
856            tried to test it.
857    
858        (b) There were problems when the value of CXX was explicitly set. Some
859            changes have been made to try to fix these, and ...
860    
861        (c) --disable-cpp can now be used to explicitly disable C++ support.
862    
863        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
864            backslash in a target when C++ was disabled. This confuses some
865            versions of "make", apparently. Using an intermediate variable solves
866            this. (Same for CPP_LOBJ.)
867    
868     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
869        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
870        necessary on certain architectures.
871    
872     4. Added a setting of -export-symbols-regex to the link command to remove
873        those symbols that are exported in the C sense, but actually are local
874        within the library, and not documented. Their names all begin with
875        "_pcre_". This is not a perfect job, because (a) we have to except some
876        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
877        available (and never for static libraries). I have made a note to try to
878        find a way round (a) in the future.
879    
880    
881    Version 6.2 01-Aug-05
882    ---------------------
883    
884     1. There was no test for integer overflow of quantifier values. A construction
885        such as {1111111111111111} would give undefined results. What is worse, if
886        a minimum quantifier for a parenthesized subpattern overflowed and became
887        negative, the calculation of the memory size went wrong. This could have
888        led to memory overwriting.
889    
890     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
891    
892     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
893        operating environments where this matters.
894    
895     4. Applied Giuseppe Maxia's patch to add additional features for controlling
896        PCRE options from within the C++ wrapper.
897    
898     5. Named capturing subpatterns were not being correctly counted when a pattern
899        was compiled. This caused two problems: (a) If there were more than 100
900        such subpatterns, the calculation of the memory needed for the whole
901        compiled pattern went wrong, leading to an overflow error. (b) Numerical
902        back references of the form \12, where the number was greater than 9, were
903        not recognized as back references, even though there were sufficient
904        previous subpatterns.
905    
906     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
907        versions of gcc, e.g. 2.95.4.
908    
909    
910    Version 6.1 21-Jun-05
911    ---------------------
912    
913     1. There was one reference to the variable "posix" in pcretest.c that was not
914        surrounded by "#if !defined NOPOSIX".
915    
916     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
917        the cross-check on the old pcre_info() function, for the benefit of the
918        cut-down version of PCRE that is currently imported into Exim.
919    
920     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
921        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
922        patterns that start (?i) but I don't think that matters. The use of (?i) is
923        just an example; this all applies to the other options as well.
924    
925     4. Since libtool seems to echo the compile commands it is issuing, the output
926        from "make" can be reduced a bit by putting "@" in front of each libtool
927        compile command.
928    
929     5. Patch from the folks at Google for configure.in to be a bit more thorough
930        in checking for a suitable C++ installation before trying to compile the
931        C++ stuff. This should fix a reported problem when a compiler was present,
932        but no suitable headers.
933    
934     6. The man pages all had just "PCRE" as their title. I have changed them to
935        be the relevant file name. I have also arranged that these names are
936        retained in the file doc/pcre.txt, which is a concatenation in text format
937        of all the man pages except the little individual ones for each function.
938    
939     7. The NON-UNIX-USE file had not been updated for the different set of source
940        files that come with release 6. I also added a few comments about the C++
941        wrapper.
942    
943    
944    Version 6.0 07-Jun-05
945    ---------------------
946    
947     1. Some minor internal re-organization to help with my DFA experiments.
948    
949     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
950        didn't matter for the library itself when fully configured, but did matter
951        when compiling without UCP support, or within Exim, where the ucp files are
952        not imported.
953    
954     3. Refactoring of the library code to split up the various functions into
955        different source modules. The addition of the new DFA matching code (see
956        below) to a single monolithic source would have made it really too
957        unwieldy, quite apart from causing all the code to be include in a
958        statically linked application, when only some functions are used. This is
959        relevant even without the DFA addition now that patterns can be compiled in
960        one application and matched in another.
961    
962        The downside of splitting up is that there have to be some external
963        functions and data tables that are used internally in different modules of
964        the library but which are not part of the API. These have all had their
965        names changed to start with "_pcre_" so that they are unlikely to clash
966        with other external names.
967    
968     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
969        a different (DFA) algorithm. Although it is slower than the original
970        function, it does have some advantages for certain types of matching
971        problem.
972    
973     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
974        including restarting after a partial match.
975    
976     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
977        defined when compiling for Windows was sent to me. I have put it into the
978        code, though I have no means of testing or verifying it.
979    
980     7. Added the pcre_refcount() auxiliary function.
981    
982     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
983        match before or at the first newline in the subject string. In pcretest,
984        the /f option on a pattern can be used to set this.
985    
986     9. A repeated \w when used in UTF-8 mode with characters greater than 256
987        would behave wrongly. This has been present in PCRE since release 4.0.
988    
989    10. A number of changes to the pcregrep command:
990    
991        (a) Refactored how -x works; insert ^(...)$ instead of setting
992            PCRE_ANCHORED and checking the length, in preparation for adding
993            something similar for -w.
994    
995        (b) Added the -w (match as a word) option.
996    
997        (c) Refactored the way lines are read and buffered so as to have more
998            than one at a time available.
999    
1000        (d) Implemented a pcregrep test script.
1001    
1002        (e) Added the -M (multiline match) option. This allows patterns to match
1003            over several lines of the subject. The buffering ensures that at least
1004            8K, or the rest of the document (whichever is the shorter) is available
1005            for matching (and similarly the previous 8K for lookbehind assertions).
1006    
1007        (f) Changed the --help output so that it now says
1008    
1009              -w, --word-regex(p)
1010    
1011            instead of two lines, one with "regex" and the other with "regexp"
1012            because that confused at least one person since the short forms are the
1013            same. (This required a bit of code, as the output is generated
1014            automatically from a table. It wasn't just a text change.)
1015    
1016        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1017            option but starts with a hyphen. Could be a pattern or a path name
1018            starting with a hyphen, for instance.
1019    
1020        (h) "-" can be given as a file name to represent stdin.
1021    
1022        (i) When file names are being printed, "(standard input)" is used for
1023            the standard input, for compatibility with GNU grep. Previously
1024            "<stdin>" was used.
1025    
1026        (j) The option --label=xxx can be used to supply a name to be used for
1027            stdin when file names are being printed. There is no short form.
1028    
1029        (k) Re-factored the options decoding logic because we are going to add
1030            two more options that take data. Such options can now be given in four
1031            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1032    
1033        (l) Added the -A, -B, and -C options for requesting that lines of context
1034            around matches be printed.
1035    
1036        (m) Added the -L option to print the names of files that do not contain
1037            any matching lines, that is, the complement of -l.
1038    
1039        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1040            continue to scan other files.
1041    
1042        (o) The -s option was incorrectly implemented. For compatibility with other
1043            greps, it now suppresses the error message for a non-existent or non-
1044            accessible file (but not the return code). There is a new option called
1045            -q that suppresses the output of matching lines, which was what -s was
1046            previously doing.
1047    
1048        (p) Added --include and --exclude options to specify files for inclusion
1049            and exclusion when recursing.
1050    
1051    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1052        Hopefully, it now does.
1053    
1054    12. Missing cast in pcre_study().
1055    
1056    13. Added an "uninstall" target to the makefile.
1057    
1058    14. Replaced "extern" in the function prototypes in Makefile.in with
1059        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1060        world, but is set differently for Windows.
1061    
1062    15. Added a second compiling function called pcre_compile2(). The only
1063        difference is that it has an extra argument, which is a pointer to an
1064        integer error code. When there is a compile-time failure, this is set
1065        non-zero, in addition to the error test pointer being set to point to an
1066        error message. The new argument may be NULL if no error number is required
1067        (but then you may as well call pcre_compile(), which is now just a
1068        wrapper). This facility is provided because some applications need a
1069        numeric error indication, but it has also enabled me to tidy up the way
1070        compile-time errors are handled in the POSIX wrapper.
1071    
1072    16. Added VPATH=.libs to the makefile; this should help when building with one
1073        prefix path and installing with another. (Or so I'm told by someone who
1074        knows more about this stuff than I do.)
1075    
1076    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1077        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1078        match everything, including newlines. This is not POSIX-compatible, but
1079        somebody wanted the feature. From pcretest it can be activated by using
1080        both the P and the s flags.
1081    
1082    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1083    
1084    19. libpcre.pc was being incorrectly installed as executable.
1085    
1086    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1087        it now also looks for '\r' so that it will work unmodified on Windows.
1088    
1089    21. Added Google's contributed C++ wrapper to the distribution.
1090    
1091    22. Added some untidy missing memory free() calls in pcretest, to keep
1092        Electric Fence happy when testing.
1093    
1094    
1095    
1096    Version 5.0 13-Sep-04
1097    ---------------------
1098    
1099     1. Internal change: literal characters are no longer packed up into items
1100        containing multiple characters in a single byte-string. Each character
1101        is now matched using a separate opcode. However, there may be more than one
1102        byte in the character in UTF-8 mode.
1103    
1104     2. The pcre_callout_block structure has two new fields: pattern_position and
1105        next_item_length. These contain the offset in the pattern to the next match
1106        item, and its length, respectively.
1107    
1108     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1109        insertion of callouts before each pattern item. Added the /C option to
1110        pcretest to make use of this.
1111    
1112     4. On the advice of a Windows user, the lines
1113    
1114          #if defined(_WIN32) || defined(WIN32)
1115          _setmode( _fileno( stdout ), 0x8000 );
1116          #endif  /* defined(_WIN32) || defined(WIN32) */
1117    
1118        have been added to the source of pcretest. This apparently does useful
1119        magic in relation to line terminators.
1120    
1121     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1122        for the benefit of those environments where the "b" makes a difference.
1123    
1124     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1125        to know about it. I have put a hack into configure.in that adds in code
1126        to set GCC=yes if CC=icc. This seems to end up at a point in the
1127        generated configure script that is early enough to affect the setting of
1128        compiler options, which is what is needed, but I have no means of testing
1129        whether it really works. (The user who reported this had patched the
1130        generated configure script, which of course I cannot do.)
1131    
1132        LATER: After change 22 below (new libtool files), the configure script
1133        seems to know about icc (and also ecc). Therefore, I have commented out
1134        this hack in configure.in.
1135    
1136     7. Added support for pkg-config (2 patches were sent in).
1137    
1138     8. Negated POSIX character classes that used a combination of internal tables
1139        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1140        [[:^ascii]]. Typically, they would match almost any characters. The other
1141        POSIX classes were not broken in this way.
1142    
1143     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1144        to find the match, as PCRE was deluded into thinking that the match had to
1145        start at the start point or following a newline. The same bug applied to
1146        patterns with negative forward assertions or any backward assertions
1147        preceding ".*" at the start, unless the pattern required a fixed first
1148        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1149    
1150    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1151        starting at the last subject character, bytes beyond the end of the subject
1152        string were read.
1153    
1154    11. Renamed the variable "class" as "classbits" to make life easier for C++
1155        users. (Previously there was a macro definition, but it apparently wasn't
1156        enough.)
1157    
1158    12. Added the new field "tables" to the extra data so that tables can be passed
1159        in at exec time, or the internal tables can be re-selected. This allows
1160        a compiled regex to be saved and re-used at a later time by a different
1161        program that might have everything at different addresses.
1162    
1163    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1164        -R library as well as a -L library.
1165    
1166    14. The debugging options of pcretest (-d on the command line or D on a
1167        pattern) showed incorrect output for anything following an extended class
1168        that contained multibyte characters and which was followed by a quantifier.
1169    
1170    15. Added optional support for general category Unicode character properties
1171        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1172        support. It adds about 90K to the size of the library. The meanings of the
1173        inbuilt class escapes such as \d and \s have NOT been changed.
1174    
1175    16. Updated pcredemo.c to include calls to free() to release the memory for the
1176        compiled pattern.
1177    
1178    17. The generated file chartables.c was being created in the source directory
1179        instead of in the building directory. This caused the build to fail if the
1180        source directory was different from the building directory, and was
1181        read-only.
1182    
1183    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1184        file. No doubt somebody will tell me if they don't make sense... Also added
1185        Dan Mooney's comments about building on OpenVMS.
1186    
1187    19. Added support for partial matching via the PCRE_PARTIAL option for
1188        pcre_exec() and the \P data escape in pcretest.
1189    
1190    20. Extended pcretest with 3 new pattern features:
1191    
1192        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1193              write the compiled pattern to the file whose name is "rest-of-line".
1194              This is a straight binary dump of the data, with the saved pointer to
1195              the character tables forced to be NULL. The study data, if any, is
1196              written too. After writing, pcretest reads a new pattern.
1197    
1198        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1199              compiled pattern from the given file. There must not be any
1200              occurrences of "<" in the file name (pretty unlikely); if there are,
1201              pcretest will instead treat the initial "<" as a pattern delimiter.
1202              After reading in the pattern, pcretest goes on to read data lines as
1203              usual.
1204    
1205        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1206              and 16-bit fields in a compiled pattern, to simulate a pattern that
1207              was compiled on a host of opposite endianness.
1208    
1209    21. The pcre-exec() function can now cope with patterns that were compiled on
1210        hosts of opposite endianness, with this restriction:
1211    
1212          As for any compiled expression that is saved and used later, the tables
1213          pointer field cannot be preserved; the extra_data field in the arguments
1214          to pcre_exec() should be used to pass in a tables address if a value
1215          other than the default internal tables were used at compile time.
1216    
1217    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1218        now diagnosed as an error. Previously, most of the time, a negative number
1219        would have been treated as zero, but if in addition "ovector" was passed as
1220        NULL, a crash could occur.
1221    
1222    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1223        new versions from the libtool 1.5 distribution (the last one is a copy of
1224        a file called libtool.m4). This seems to have fixed the need to patch
1225        "configure" to support Darwin 1.3 (which I used to do). However, I still
1226        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1227        workstation).
1228    
1229    24. Changed the PCRE licence to be the more standard "BSD" licence.
1230    
1231    
1232    Version 4.5 01-Dec-03
1233    ---------------------
1234    
1235     1. There has been some re-arrangement of the code for the match() function so
1236        that it can be compiled in a version that does not call itself recursively.
1237        Instead, it keeps those local variables that need separate instances for
1238        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1239        needs to "recurse". Keeping track of where control must go is done by means
1240        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1241        hide most of the details from the main code, and operates only if
1242        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1243        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1244        operating.
1245    
1246        To make it easier for callers to provide specially tailored get/free
1247        functions for this usage, two new functions, pcre_stack_malloc, and
1248        pcre_stack_free, are used. They are always called in strict stacking order,
1249        and the size of block requested is always the same.
1250    
1251        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1252        PCRE has been compiled to use the stack or the heap for recursion. The
1253        -C option of pcretest uses this to show which version is compiled.
1254    
1255        A new data escape \S, is added to pcretest; it causes the amounts of store
1256        obtained and freed by both kinds of malloc/free at match time to be added
1257        to the output.
1258    
1259     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1260        what's available on my current Linux desktop machine.
1261    
1262     3. When matching a UTF-8 string, the test for a valid string at the start has
1263        been extended. If start_offset is not zero, PCRE now checks that it points
1264        to a byte that is the start of a UTF-8 character. If not, it returns
1265        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1266        this is necessary because there may be backward assertions in the pattern.
1267        When matching the same subject several times, it may save resources to use
1268        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1269    
1270     4. The code for checking the validity of UTF-8 strings has been tightened so
1271        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1272        containing "overlong sequences".
1273    
1274     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1275        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1276        should have been "&", but it just so happened that all the cases this let
1277        through by mistake were picked up later in the function.
1278    
1279     6. I had used a variable called "isblank" - this is a C99 function, causing
1280        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1281    
1282     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1283        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1284        so the version is shown; (c) stop "make test" echoing "./RunTest".
1285    
1286     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1287    
1288     9. The prototype for memmove() for systems that don't have it was using
1289        size_t, but the inclusion of the header that defines size_t was later. I've
1290        moved the #includes for the C headers earlier to avoid this.
1291    
1292    10. Added some adjustments to the code to make it easier to compiler on certain
1293        special systems:
1294    
1295          (a) Some "const" qualifiers were missing.
1296          (b) Added the macro EXPORT before all exported functions; by default this
1297              is defined to be empty.
1298          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1299              that it reads its output file name as an argument instead of writing
1300              to the standard output and assuming this can be redirected.
1301    
1302    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1303        class containing characters with values greater than 255, PCRE compilation
1304        went into a loop.
1305    
1306    12. A recursive reference to a subpattern that was within another subpattern
1307        that had a minimum quantifier of zero caused PCRE to crash. For example,
1308        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1309        recursion. If the recursively-called subpattern itself had a zero repeat,
1310        that was OK.
1311    
1312    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1313        buffer into which it was copied (for escape processing) was still set at
1314        1024, so long lines caused crashes.
1315    
1316    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1317        "internal error: code overflow...". This applied to any character class
1318        that was followed by a possessive quantifier.
1319    
1320    15. Modified the Makefile to add libpcre.la as a prerequisite for
1321        libpcreposix.la because I was told this is needed for a parallel build to
1322        work.
1323    
1324    16. If a pattern that contained .* following optional items at the start was
1325        studied, the wrong optimizing data was generated, leading to matching
1326        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1327        matching string must start with a or b or c. The correct conclusion for
1328        this pattern is that a match can start with any character.
1329    
1330    
1331  Version 4.4 13-Aug-03  Version 4.4 13-Aug-03
1332  ---------------------  ---------------------
1333    

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