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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 7.1 05-Mar-07
5    ---------------------
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.
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.
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 maintain/132html script that I use to
25        generate HTML has been updated to handle .nf/.fi and to complain if it
26        encounters .br or .in.
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).
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 !compile.txt,
36        !linklib.txt, and pcregexp.pas.
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.
42     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
43        that is needed.
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.
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.
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.
63    10. The emulated memmove() function in pcre_internal.h (provided for those
64        environments that have neither memmove() nor bcopy()) was defining its
65        arguments as char * instead of void *.
67    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
68        and Detrail to create the HTML documentation, the .txt form of the man
69        pages, and it removes trailing spaces from listed files. It also creates
70        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
71        case, it wraps all the #defines with #ifndefs. This script should be run
72        before "make dist".
75    Version 7.0 19-Dec-06
76    ---------------------
78     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
79        moving to gcc 4.1.1.
81     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
82        sys/time.h, which is documented as needed for this function. It doesn't
83        seem to matter on Linux, but it showed up on some releases of OS X.
85     3. It seems that there are systems where bytes whose values are greater than
86        127 match isprint() in the "C" locale. The "C" locale should be the
87        default when a C program starts up. In most systems, only ASCII printing
88        characters match isprint(). This difference caused the output from pcretest
89        to vary, making some of the tests fail. I have changed pcretest so that:
91        (a) When it is outputting text in the compiled version of a pattern, bytes
92            other than 32-126 are always shown as hex escapes.
94        (b) When it is outputting text that is a matched part of a subject string,
95            it does the same, unless a different locale has been set for the match
96            (using the /L modifier). In this case, it uses isprint() to decide.
98     4. Fixed a major bug that caused incorrect computation of the amount of memory
99        required for a compiled pattern when options that changed within the
100        pattern affected the logic of the preliminary scan that determines the
101        length. The relevant options are -x, and -i in UTF-8 mode. The result was
102        that the computed length was too small. The symptoms of this bug were
103        either the PCRE error "internal error: code overflow" from pcre_compile(),
104        or a glibc crash with a message such as "pcretest: free(): invalid next
105        size (fast)". Examples of patterns that provoked this bug (shown in
106        pcretest format) are:
108          /(?-x: )/x
109          /(?x)(?-x: \s*#\s*)/
110          /((?i)[\x{c0}])/8
111          /(?i:[\x{c0}])/8
113        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
114        is now done differently.
116     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
117        wrapper classes; (b) implement a new function in the C++ scanner that is
118        more efficient than the old way of doing things because it avoids levels of
119        recursion in the regex matching; (c) add a paragraph to the documentation
120        for the FullMatch() function.
122     6. The escape sequence \n was being treated as whatever was defined as
123        "newline". Not only was this contrary to the documentation, which states
124        that \n is character 10 (hex 0A), but it also went horribly wrong when
125        "newline" was defined as CRLF. This has been fixed.
127     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
128        was being set to -1 for the "end of line" case (supposedly a value that no
129        character can have). Though this value is never used (the check for end of
130        line is "zero bytes in current character"), it caused compiler complaints.
131        I've changed it to 0xffffffff.
133     8. In pcre_version.c, the version string was being built by a sequence of
134        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
135        string (as it is for production releases) called a macro with an empty
136        argument. The C standard says the result of this is undefined. The gcc
137        compiler treats it as an empty string (which was what was wanted) but it is
138        reported that Visual C gives an error. The source has been hacked around to
139        avoid this problem.
141     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
142        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
143        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
144        of them did).
146    10. Originally, pcretest opened its input and output without "b"; then I was
147        told that "b" was needed in some environments, so it was added for release
148        5.0 to both the input and output. (It makes no difference on Unix-like
149        systems.) Later I was told that it is wrong for the input on Windows. I've
150        now abstracted the modes into two macros, to make it easier to fiddle with
151        them, and removed "b" from the input mode under Windows.
153    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
155    12. Added -help and --help to pcretest as an official way of being reminded
156        of the options.
158    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
159        and pcrecpp.cc because they annoy compilers at high warning levels.
161    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
163    15. Fixed an occurrence of == in configure.ac that should have been = (shell
164        scripts are not C programs :-) and which was not noticed because it works
165        on Linux.
167    16. pcretest is supposed to handle any length of pattern and data line (as one
168        line or as a continued sequence of lines) by extending its input buffer if
169        necessary. This feature was broken for very long pattern lines, leading to
170        a string of junk being passed to pcre_compile() if the pattern was longer
171        than about 50K.
173    17. I have done a major re-factoring of the way pcre_compile() computes the
174        amount of memory needed for a compiled pattern. Previously, there was code
175        that made a preliminary scan of the pattern in order to do this. That was
176        OK when PCRE was new, but as the facilities have expanded, it has become
177        harder and harder to keep it in step with the real compile phase, and there
178        have been a number of bugs (see for example, 4 above). I have now found a
179        cunning way of running the real compile function in a "fake" mode that
180        enables it to compute how much memory it would need, while actually only
181        ever using a few hundred bytes of working memory and without too many
182        tests of the mode. This should make future maintenance and development
183        easier. A side effect of this work is that the limit of 200 on the nesting
184        depth of parentheses has been removed (though this was never a serious
185        limitation, I suspect). However, there is a downside: pcre_compile() now
186        runs more slowly than before (30% or more, depending on the pattern). I
187        hope this isn't a big issue. There is no effect on runtime performance.
189    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
190        newline (only possible for the last line of a file) and it was a
191        pattern that set a locale (followed by /Lsomething), pcretest crashed.
193    19. Added additional timing features to pcretest. (1) The -tm option now times
194        matching only, not compiling. (2) Both -t and -tm can be followed, as a
195        separate command line item, by a number that specifies the number of
196        repeats to use when timing. The default is 50000; this gives better
197        precision, but takes uncomfortably long for very large patterns.
199    20. Extended pcre_study() to be more clever in cases where a branch of a
200        subpattern has no definite first character. For example, (a*|b*)[cd] would
201        previously give no result from pcre_study(). Now it recognizes that the
202        first character must be a, b, c, or d.
204    21. There was an incorrect error "recursive call could loop indefinitely" if
205        a subpattern (or the entire pattern) that was being tested for matching an
206        empty string contained only one non-empty item after a nested subpattern.
207        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
208        incorrectly, because the \d was being skipped in the check.
210    22. The pcretest program now has a new pattern option /B and a command line
211        option -b, which is equivalent to adding /B to every pattern. This causes
212        it to show the compiled bytecode, without the additional information that
213        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
214        is the same as /B/I).
216    23. A new optimization is now able automatically to treat some sequences such
217        as a*b as a*+b. More specifically, if something simple (such as a character
218        or a simple class like \d) has an unlimited quantifier, and is followed by
219        something that cannot possibly match the quantified thing, the quantifier
220        is automatically "possessified".
222    24. A recursive reference to a subpattern whose number was greater than 39
223        went wrong under certain circumstances in UTF-8 mode. This bug could also
224        have affected the operation of pcre_study().
226    25. Realized that a little bit of performance could be had by replacing
227        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
229    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
231    27. Possessive quantifiers such as a++ were previously implemented by turning
232        them into atomic groups such as ($>a+). Now they have their own opcodes,
233        which improves performance. This includes the automatically created ones
234        from 23 above.
236    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
237        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
238        the first matched character to be a colon. This applied both to named and
239        numbered groups.
241    29. The ucpinternal.h header file was missing its idempotency #ifdef.
243    30. I was sent a "project" file called libpcre.a.dev which I understand makes
244        building PCRE on Windows easier, so I have included it in the distribution.
246    31. There is now a check in pcretest against a ridiculously large number being
247        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
248        loop, the loop is abandoned.
250    32. Forward references to subpatterns in conditions such as (?(2)...) where
251        subpattern 2 is defined later cause pcre_compile() to search forwards in
252        the pattern for the relevant set of parentheses. This search went wrong
253        when there were unescaped parentheses in a character class, parentheses
254        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
256    33. "Subroutine" calls and backreferences were previously restricted to
257        referencing subpatterns earlier in the regex. This restriction has now
258        been removed.
260    34. Added a number of extra features that are going to be in Perl 5.10. On the
261        whole, these are just syntactic alternatives for features that PCRE had
262        previously implemented using the Python syntax or my own invention. The
263        other formats are all retained for compatibility.
265        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
266            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
267            also .NET compatible.
269        (b) A recursion or subroutine call to a named group can now be defined as
270            (?&name) as well as (?P>name).
272        (c) A backreference to a named group can now be defined as \k<name> or
273            \k'name' as well as (?P=name). The new forms, as well as being in Perl
274            5.10, are also .NET compatible.
276        (d) A conditional reference to a named group can now use the syntax
277            (?(<name>) or (?('name') as well as (?(name).
279        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
280            groups (named and numbered) that are never evaluated inline, but can be
281            called as "subroutines" from elsewhere. In effect, the DEFINE condition
282            is always false. There may be only one alternative in such a group.
284        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
285            as the simple (?(R). The condition is true only if the most recent
286            recursion is that of the given number or name. It does not search out
287            through the entire recursion stack.
289        (g) The escape \gN or \g{N} has been added, where N is a positive or
290            negative number, specifying an absolute or relative reference.
292    35. Tidied to get rid of some further signed/unsigned compiler warnings and
293        some "unreachable code" warnings.
295    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
296        things, this adds five new scripts.
298    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
299        There were also incompatibilities regarding the handling of \Q..\E inside
300        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
301        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
303    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
304        matches an empty string, and forcibly breaks the loop. There were bugs in
305        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
306        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
307        separate and independent bugs (that affected different cases) have been
308        fixed.
310    39. Refactored the code to abolish the use of different opcodes for small
311        capturing bracket numbers. This is a tidy that I avoided doing when I
312        removed the limit on the number of capturing brackets for 3.5 back in 2001.
313        The new approach is not only tidier, it makes it possible to reduce the
314        memory needed to fix the previous bug (38).
316    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
317        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
318        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
319        mode.
321    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
322        report.
324    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
325        copy construction and assignment in the C++ wrapper.
327    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
328        couple of bugs that could have given wrong results in the "--newline=crlf"
329        case.
331    44. Added a number of casts and did some reorganization of signed/unsigned int
332        variables following suggestions from Dair Grant. Also renamed the variable
333        "this" as "item" because it is a C++ keyword.
335    45. Arranged for dftables to add
337          #include "pcre_internal.h"
339        to pcre_chartables.c because without it, gcc 4.x may remove the array
340        definition from the final binary if PCRE is built into a static library and
341        dead code stripping is activated.
343    46. For an unanchored pattern, if a match attempt fails at the start of a
344        newline sequence, and the newline setting is CRLF or ANY, and the next two
345        characters are CRLF, advance by two characters instead of one.
348    Version 6.7 04-Jul-06
349    ---------------------
351     1. In order to handle tests when input lines are enormously long, pcretest has
352        been re-factored so that it automatically extends its buffers when
353        necessary. The code is crude, but this _is_ just a test program. The
354        default size has been increased from 32K to 50K.
356     2. The code in pcre_study() was using the value of the re argument before
357        testing it for NULL. (Of course, in any sensible call of the function, it
358        won't be NULL.)
360     3. The memmove() emulation function in pcre_internal.h, which is used on
361        systems that lack both memmove() and bcopy() - that is, hardly ever -
362        was missing a "static" storage class specifier.
364     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
365        containing an extended class (one that cannot be represented by a bitmap
366        because it contains high-valued characters or Unicode property items, e.g.
367        [\pZ]). Almost always one would set UTF-8 mode when processing such a
368        pattern, but PCRE should not loop if you do not (it no longer does).
369        [Detail: two cases were found: (a) a repeated subpattern containing an
370        extended class; (b) a recursive reference to a subpattern that followed a
371        previous extended class. It wasn't skipping over the extended class
372        correctly when UTF-8 mode was not set.]
374     5. A negated single-character class was not being recognized as fixed-length
375        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
376        compile error "lookbehind assertion is not fixed length".
378     6. The RunPerlTest auxiliary script was showing an unexpected difference
379        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
380        write a Perl script that can interpret lines of an input file either as
381        byte characters or as UTF-8, which is what "perltest" was being required to
382        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
383        can't do is switch easily at run time between having the "use utf8;" pragma
384        or not. In the end, I fudged it by using the RunPerlTest script to insert
385        "use utf8;" explicitly for the UTF-8 tests.
387     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
388        the end of the subject string, contrary to the documentation and to what
389        Perl does. This was true of both matching functions. Now it matches only at
390        the start of the subject and immediately after *internal* newlines.
392     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
393        a pointer to an int instead of a pointer to an unsigned long int. This
394        caused problems on 64-bit systems.
396     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
397        instance of the 'standard' template library not being so standard".
399    10. There was no check on the number of named subpatterns nor the maximum
400        length of a subpattern name. The product of these values is used to compute
401        the size of the memory block for a compiled pattern. By supplying a very
402        long subpattern name and a large number of named subpatterns, the size
403        computation could be caused to overflow. This is now prevented by limiting
404        the length of names to 32 characters, and the number of named subpatterns
405        to 10,000.
407    11. Subpatterns that are repeated with specific counts have to be replicated in
408        the compiled pattern. The size of memory for this was computed from the
409        length of the subpattern and the repeat count. The latter is limited to
410        65535, but there was no limit on the former, meaning that integer overflow
411        could in principle occur. The compiled length of a repeated subpattern is
412        now limited to 30,000 bytes in order to prevent this.
414    12. Added the optional facility to have named substrings with the same name.
416    13. Added the ability to use a named substring as a condition, using the
417        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
418        are numbers (not recommended). Forward references are permitted.
420    14. Added forward references in named backreferences (if you see what I mean).
422    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
423        pattern could run off the end of the subject. For example, the pattern
424        "(?s)(.{1,5})"8 did this with the subject "ab".
426    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
427        PCRE_CASELESS was set when matching characters that were quantified with ?
428        or *.
430    17. A character class other than a single negated character that had a minimum
431        but no maximum quantifier - for example [ab]{6,} - was not handled
432        correctly by pce_dfa_exec(). It would match only one character.
434    18. A valid (though odd) pattern that looked like a POSIX character
435        class but used an invalid character after [ (for example [[,abc,]]) caused
436        pcre_compile() to give the error "Failed: internal error: code overflow" or
437        in some cases to crash with a glibc free() error. This could even happen if
438        the pattern terminated after [[ but there just happened to be a sequence of
439        letters, a binary zero, and a closing ] in the memory that followed.
441    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
442        over the years. Originally (before any Unicode support), just the bottom 8
443        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
444        output from "man perlunicode" includes this:
446          The regular expression compiler produces polymorphic opcodes.  That
447          is, the pattern adapts to the data and automatically switches to
448          the Unicode character scheme when presented with Unicode data--or
449          instead uses a traditional byte scheme when presented with byte
450          data.
452        Sadly, a wide octal escape does not cause a switch, and in a string with
453        no other multibyte characters, these octal escapes are treated as before.
454        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
455        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
456        Unicode string.
458        I have not perpetrated such confusion in PCRE. Up till now, it took just
459        the bottom 8 bits, as in old Perl. I have now made octal escapes with
460        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
461        translate to the appropriate multibyte character.
463    29. Applied some refactoring to reduce the number of warnings from Microsoft
464        and Borland compilers. This has included removing the fudge introduced
465        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
466        a warning about an unused variable.
468    21. PCRE has not included VT (character 0x0b) in the set of whitespace
469        characters since release 4.0, because Perl (from release 5.004) does not.
470        [Or at least, is documented not to: some releases seem to be in conflict
471        with the documentation.] However, when a pattern was studied with
472        pcre_study() and all its branches started with \s, PCRE still included VT
473        as a possible starting character. Of course, this did no harm; it just
474        caused an unnecessary match attempt.
476    22. Removed a now-redundant internal flag bit that recorded the fact that case
477        dependency changed within the pattern. This was once needed for "required
478        byte" processing, but is no longer used. This recovers a now-scarce options
479        bit. Also moved the least significant internal flag bit to the most-
480        significant bit of the word, which was not previously used (hangover from
481        the days when it was an int rather than a uint) to free up another bit for
482        the future.
484    23. Added support for CRLF line endings as well as CR and LF. As well as the
485        default being selectable at build time, it can now be changed at runtime
486        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
487        specify that it is scanning data with non-default line endings.
489    24. Changed the definition of CXXLINK to make it agree with the definition of
490        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
492    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
493        recursions. This makes a big different to stack usage for some patterns.
495    26. If a subpattern containing a named recursion or subroutine reference such
496        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
497        the space required for the compiled pattern went wrong and gave too small a
498        value. Depending on the environment, this could lead to "Failed: internal
499        error: code overflow at offset 49" or "glibc detected double free or
500        corruption" errors.
502    27. Applied patches from Google (a) to support the new newline modes and (b) to
503        advance over multibyte UTF-8 characters in GlobalReplace.
505    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
506        difference for some implementation of PCRE in some Windows version.
508    29. Added some extra testing facilities to pcretest:
510        \q<number>   in a data line sets the "match limit" value
511        \Q<number>   in a data line sets the "match recursion limt" value
512        -S <number>  sets the stack size, where <number> is in megabytes
514        The -S option isn't available for Windows.
517    Version 6.6 06-Feb-06
518    ---------------------
520     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
521        in pcreposix.h. I have copied the definition from pcre.h.
523     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
524        because pcre.h is no longer a built file.
526     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
527        not normally included in the compiled code.
530    Version 6.5 01-Feb-06
531    ---------------------
533     1. When using the partial match feature with pcre_dfa_exec(), it was not
534        anchoring the second and subsequent partial matches at the new starting
535        point. This could lead to incorrect results. For example, with the pattern
536        /1234/, partially matching against "123" and then "a4" gave a match.
538     2. Changes to pcregrep:
540        (a) All non-match returns from pcre_exec() were being treated as failures
541            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
542            error message is output. Some extra information is given for the
543            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
544            probably the only errors that are likely to be caused by users (by
545            specifying a regex that has nested indefinite repeats, for instance).
546            If there are more than 20 of these errors, pcregrep is abandoned.
548        (b) A binary zero was treated as data while matching, but terminated the
549            output line if it was written out. This has been fixed: binary zeroes
550            are now no different to any other data bytes.
552        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
553            used to set a locale for matching. The --locale=xxxx long option has
554            been added (no short equivalent) to specify a locale explicitly on the
555            pcregrep command, overriding the environment variables.
557        (d) When -B was used with -n, some line numbers in the output were one less
558            than they should have been.
560        (e) Added the -o (--only-matching) option.
562        (f) If -A or -C was used with -c (count only), some lines of context were
563            accidentally printed for the final match.
565        (g) Added the -H (--with-filename) option.
567        (h) The combination of options -rh failed to suppress file names for files
568            that were found from directory arguments.
570        (i) Added the -D (--devices) and -d (--directories) options.
572        (j) Added the -F (--fixed-strings) option.
574        (k) Allow "-" to be used as a file name for -f as well as for a data file.
576        (l) Added the --colo(u)r option.
578        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
579            is not present by default.
581     3. A nasty bug was discovered in the handling of recursive patterns, that is,
582        items such as (?R) or (?1), when the recursion could match a number of
583        alternatives. If it matched one of the alternatives, but subsequently,
584        outside the recursion, there was a failure, the code tried to back up into
585        the recursion. However, because of the way PCRE is implemented, this is not
586        possible, and the result was an incorrect result from the match.
588        In order to prevent this happening, the specification of recursion has
589        been changed so that all such subpatterns are automatically treated as
590        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
592     4. I had overlooked the fact that, in some locales, there are characters for
593        which isalpha() is true but neither isupper() nor islower() are true. In
594        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
595        and ordfeminine) are like this. This affected the treatment of \w and \W
596        when they appeared in character classes, but not when they appeared outside
597        a character class. The bit map for "word" characters is now created
598        separately from the results of isalnum() instead of just taking it from the
599        upper, lower, and digit maps. (Plus the underscore character, of course.)
601     5. The above bug also affected the handling of POSIX character classes such as
602        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
603        permanent tables. Instead, the bit maps for such a class were previously
604        created as the appropriate unions of the upper, lower, and digit bitmaps.
605        Now they are created by subtraction from the [[:word:]] class, which has
606        its own bitmap.
608     6. The [[:blank:]] character class matches horizontal, but not vertical space.
609        It is created by subtracting the vertical space characters (\x09, \x0a,
610        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
611        subtraction was done in the overall bitmap for a character class, meaning
612        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
613        be recognized. This bug has been fixed.
615     7. Patches from the folks at Google:
617          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
618          real life, but is still worth protecting against".
620          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
621          regular expressions".
623          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
624          have it.
626          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
627          "configure" and the latter not, in order to fix a problem somebody had
628          with compiling the Arg class on HP-UX.
630          (e) Improve the error-handling of the C++ wrapper a little bit.
632          (f) New tests for checking recursion limiting.
634     8. The pcre_memmove() function, which is used only if the environment does not
635        have a standard memmove() function (and is therefore rarely compiled),
636        contained two bugs: (a) use of int instead of size_t, and (b) it was not
637        returning a result (though PCRE never actually uses the result).
639     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
640        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
641        returned instead of calling malloc() with an overflowing number that would
642        most likely cause subsequent chaos.
644    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
646    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
647        with this option is matched, the nmatch and pmatch options of regexec() are
648        ignored.
650    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
651        provided in case anyone wants to the the POSIX interface with UTF-8
652        strings.
654    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
655        C++ linking (needed for some HP-UX environments).
657    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
658        (unused parameter) and in the pcre_printint() function (omitted "default"
659        switch label when the default is to do nothing).
661    15. Added some code to make it possible, when PCRE is compiled as a C++
662        library, to replace subject pointers for pcre_exec() with a smart pointer
663        class, thus making it possible to process discontinuous strings.
665    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
666        much the same function. They were added by different people who were trying
667        to make PCRE easy to compile on non-Unix systems. It has been suggested
668        that PCRE_EXPORT be abolished now that there is more automatic apparatus
669        for compiling on Windows systems. I have therefore replaced it with
670        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
671        defaults to "extern" for C or "extern C" for C++, which works fine on
672        Unix-like systems. It is now possible to override the value of PCRE_DATA_
673        SCOPE with something explicit in config.h. In addition:
675        (a) pcreposix.h still had just "extern" instead of either of these macros;
676            I have replaced it with PCRE_DATA_SCOPE.
678        (b) Functions such as _pcre_xclass(), which are internal to the library,
679            but external in the C sense, all had PCRE_EXPORT in their definitions.
680            This is apparently wrong for the Windows case, so I have removed it.
681            (It makes no difference on Unix-like systems.)
683    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
684        of recursive calls to match(). This is different to MATCH_LIMIT because
685        that limits the total number of calls to match(), not all of which increase
686        the depth of recursion. Limiting the recursion depth limits the amount of
687        stack (or heap if NO_RECURSE is set) that is used. The default can be set
688        when PCRE is compiled, and changed at run time. A patch from Google adds
689        this functionality to the C++ interface.
691    18. Changes to the handling of Unicode character properties:
693        (a) Updated the table to Unicode 4.1.0.
695        (b) Recognize characters that are not in the table as "Cn" (undefined).
697        (c) I revised the way the table is implemented to a much improved format
698            which includes recognition of ranges. It now supports the ranges that
699            are defined in UnicodeData.txt, and it also amalgamates other
700            characters into ranges. This has reduced the number of entries in the
701            table from around 16,000 to around 3,000, thus reducing its size
702            considerably. I realized I did not need to use a tree structure after
703            all - a binary chop search is just as efficient. Having reduced the
704            number of entries, I extended their size from 6 bytes to 8 bytes to
705            allow for more data.
707        (d) Added support for Unicode script names via properties such as \p{Han}.
709    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
710        matching that character.
712    20. When matching a repeated Unicode property with a minimum greater than zero,
713        (for example \pL{2,}), PCRE could look past the end of the subject if it
714        reached it while seeking the minimum number of characters. This could
715        happen only if some of the characters were more than one byte long, because
716        there is a check for at least the minimum number of bytes.
718    21. Refactored the implementation of \p and \P so as to be more general, to
719        allow for more different types of property in future. This has changed the
720        compiled form incompatibly. Anybody with saved compiled patterns that use
721        \p or \P will have to recompile them.
723    22. Added "Any" and "L&" to the supported property types.
725    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
726        but give a compile time error if the value is greater than 0xff.
728    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
729        accidentally not being installed or uninstalled.
731    25. The pcre.h file was built from pcre.h.in, but the only changes that were
732        made were to insert the current release number. This seemed silly, because
733        it made things harder for people building PCRE on systems that don't run
734        "configure". I have turned pcre.h into a distributed file, no longer built
735        by "configure", with the version identification directly included. There is
736        no longer a pcre.h.in file.
738        However, this change necessitated a change to the pcre-config script as
739        well. It is built from pcre-config.in, and one of the substitutions was the
740        release number. I have updated configure.ac so that ./configure now finds
741        the release number by grepping pcre.h.
743    26. Added the ability to run the tests under valgrind.
746    Version 6.4 05-Sep-05
747    ---------------------
749     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
750        "--" to be printed when multiple files were scanned, even when none of the
751        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
752        consider it to be a bug, and have restored the previous behaviour.
754     2. A couple of code tidies to get rid of compiler warnings.
756     3. The pcretest program used to cheat by referring to symbols in the library
757        whose names begin with _pcre_. These are internal symbols that are not
758        really supposed to be visible externally, and in some environments it is
759        possible to suppress them. The cheating is now confined to including
760        certain files from the library's source, which is a bit cleaner.
762     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
763        file's purpose clearer.
765     5. Reorganized pcre_ucp_findchar().
768    Version 6.3 15-Aug-05
769    ---------------------
771     1. The file libpcre.pc.in did not have general read permission in the tarball.
773     2. There were some problems when building without C++ support:
775        (a) If C++ support was not built, "make install" and "make test" still
776            tried to test it.
778        (b) There were problems when the value of CXX was explicitly set. Some
779            changes have been made to try to fix these, and ...
781        (c) --disable-cpp can now be used to explicitly disable C++ support.
783        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
784            backslash in a target when C++ was disabled. This confuses some
785            versions of "make", apparently. Using an intermediate variable solves
786            this. (Same for CPP_LOBJ.)
788     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
789        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
790        necessary on certain architectures.
792     4. Added a setting of -export-symbols-regex to the link command to remove
793        those symbols that are exported in the C sense, but actually are local
794        within the library, and not documented. Their names all begin with
795        "_pcre_". This is not a perfect job, because (a) we have to except some
796        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
797        available (and never for static libraries). I have made a note to try to
798        find a way round (a) in the future.
801    Version 6.2 01-Aug-05
802    ---------------------
804     1. There was no test for integer overflow of quantifier values. A construction
805        such as {1111111111111111} would give undefined results. What is worse, if
806        a minimum quantifier for a parenthesized subpattern overflowed and became
807        negative, the calculation of the memory size went wrong. This could have
808        led to memory overwriting.
810     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
812     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
813        operating environments where this matters.
815     4. Applied Giuseppe Maxia's patch to add additional features for controlling
816        PCRE options from within the C++ wrapper.
818     5. Named capturing subpatterns were not being correctly counted when a pattern
819        was compiled. This caused two problems: (a) If there were more than 100
820        such subpatterns, the calculation of the memory needed for the whole
821        compiled pattern went wrong, leading to an overflow error. (b) Numerical
822        back references of the form \12, where the number was greater than 9, were
823        not recognized as back references, even though there were sufficient
824        previous subpatterns.
826     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
827        versions of gcc, e.g. 2.95.4.
830    Version 6.1 21-Jun-05
831    ---------------------
833     1. There was one reference to the variable "posix" in pcretest.c that was not
834        surrounded by "#if !defined NOPOSIX".
836     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
837        the cross-check on the old pcre_info() function, for the benefit of the
838        cut-down version of PCRE that is currently imported into Exim.
840     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
841        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
842        patterns that start (?i) but I don't think that matters. The use of (?i) is
843        just an example; this all applies to the other options as well.
845     4. Since libtool seems to echo the compile commands it is issuing, the output
846        from "make" can be reduced a bit by putting "@" in front of each libtool
847        compile command.
849     5. Patch from the folks at Google for configure.in to be a bit more thorough
850        in checking for a suitable C++ installation before trying to compile the
851        C++ stuff. This should fix a reported problem when a compiler was present,
852        but no suitable headers.
854     6. The man pages all had just "PCRE" as their title. I have changed them to
855        be the relevant file name. I have also arranged that these names are
856        retained in the file doc/pcre.txt, which is a concatenation in text format
857        of all the man pages except the little individual ones for each function.
859     7. The NON-UNIX-USE file had not been updated for the different set of source
860        files that come with release 6. I also added a few comments about the C++
861        wrapper.
864  Version 6.0 07-Jun-05  Version 6.0 07-Jun-05
865  ---------------------  ---------------------

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