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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.
11    Version 7.0 19-Dec-06
12    ---------------------
14     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
15        moving to gcc 4.1.1.
17     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
18        sys/time.h, which is documented as needed for this function. It doesn't
19        seem to matter on Linux, but it showed up on some releases of OS X.
21     3. It seems that there are systems where bytes whose values are greater than
22        127 match isprint() in the "C" locale. The "C" locale should be the
23        default when a C program starts up. In most systems, only ASCII printing
24        characters match isprint(). This difference caused the output from pcretest
25        to vary, making some of the tests fail. I have changed pcretest so that:
27        (a) When it is outputting text in the compiled version of a pattern, bytes
28            other than 32-126 are always shown as hex escapes.
30        (b) When it is outputting text that is a matched part of a subject string,
31            it does the same, unless a different locale has been set for the match
32            (using the /L modifier). In this case, it uses isprint() to decide.
34     4. Fixed a major bug that caused incorrect computation of the amount of memory
35        required for a compiled pattern when options that changed within the
36        pattern affected the logic of the preliminary scan that determines the
37        length. The relevant options are -x, and -i in UTF-8 mode. The result was
38        that the computed length was too small. The symptoms of this bug were
39        either the PCRE error "internal error: code overflow" from pcre_compile(),
40        or a glibc crash with a message such as "pcretest: free(): invalid next
41        size (fast)". Examples of patterns that provoked this bug (shown in
42        pcretest format) are:
44          /(?-x: )/x
45          /(?x)(?-x: \s*#\s*)/
46          /((?i)[\x{c0}])/8
47          /(?i:[\x{c0}])/8
49        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
50        is now done differently.
52     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
53        wrapper classes; (b) implement a new function in the C++ scanner that is
54        more efficient than the old way of doing things because it avoids levels of
55        recursion in the regex matching; (c) add a paragraph to the documentation
56        for the FullMatch() function.
58     6. The escape sequence \n was being treated as whatever was defined as
59        "newline". Not only was this contrary to the documentation, which states
60        that \n is character 10 (hex 0A), but it also went horribly wrong when
61        "newline" was defined as CRLF. This has been fixed.
63     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
64        was being set to -1 for the "end of line" case (supposedly a value that no
65        character can have). Though this value is never used (the check for end of
66        line is "zero bytes in current character"), it caused compiler complaints.
67        I've changed it to 0xffffffff.
69     8. In pcre_version.c, the version string was being built by a sequence of
70        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
71        string (as it is for production releases) called a macro with an empty
72        argument. The C standard says the result of this is undefined. The gcc
73        compiler treats it as an empty string (which was what was wanted) but it is
74        reported that Visual C gives an error. The source has been hacked around to
75        avoid this problem.
77     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
78        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
79        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
80        of them did).
82    10. Originally, pcretest opened its input and output without "b"; then I was
83        told that "b" was needed in some environments, so it was added for release
84        5.0 to both the input and output. (It makes no difference on Unix-like
85        systems.) Later I was told that it is wrong for the input on Windows. I've
86        now abstracted the modes into two macros, to make it easier to fiddle with
87        them, and removed "b" from the input mode under Windows.
89    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
91    12. Added -help and --help to pcretest as an official way of being reminded
92        of the options.
94    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
95        and pcrecpp.cc because they annoy compilers at high warning levels.
97    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
99    15. Fixed an occurrence of == in configure.ac that should have been = (shell
100        scripts are not C programs :-) and which was not noticed because it works
101        on Linux.
103    16. pcretest is supposed to handle any length of pattern and data line (as one
104        line or as a continued sequence of lines) by extending its input buffer if
105        necessary. This feature was broken for very long pattern lines, leading to
106        a string of junk being passed to pcre_compile() if the pattern was longer
107        than about 50K.
109    17. I have done a major re-factoring of the way pcre_compile() computes the
110        amount of memory needed for a compiled pattern. Previously, there was code
111        that made a preliminary scan of the pattern in order to do this. That was
112        OK when PCRE was new, but as the facilities have expanded, it has become
113        harder and harder to keep it in step with the real compile phase, and there
114        have been a number of bugs (see for example, 4 above). I have now found a
115        cunning way of running the real compile function in a "fake" mode that
116        enables it to compute how much memory it would need, while actually only
117        ever using a few hundred bytes of working memory and without too many
118        tests of the mode. This should make future maintenance and development
119        easier. A side effect of this work is that the limit of 200 on the nesting
120        depth of parentheses has been removed (though this was never a serious
121        limitation, I suspect). However, there is a downside: pcre_compile() now
122        runs more slowly than before (30% or more, depending on the pattern). I
123        hope this isn't a big issue. There is no effect on runtime performance.
125    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
126        newline (only possible for the last line of a file) and it was a
127        pattern that set a locale (followed by /Lsomething), pcretest crashed.
129    19. Added additional timing features to pcretest. (1) The -tm option now times
130        matching only, not compiling. (2) Both -t and -tm can be followed, as a
131        separate command line item, by a number that specifies the number of
132        repeats to use when timing. The default is 50000; this gives better
133        precision, but takes uncomfortably long for very large patterns.
135    20. Extended pcre_study() to be more clever in cases where a branch of a
136        subpattern has no definite first character. For example, (a*|b*)[cd] would
137        previously give no result from pcre_study(). Now it recognizes that the
138        first character must be a, b, c, or d.
140    21. There was an incorrect error "recursive call could loop indefinitely" if
141        a subpattern (or the entire pattern) that was being tested for matching an
142        empty string contained only one non-empty item after a nested subpattern.
143        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
144        incorrectly, because the \d was being skipped in the check.
146    22. The pcretest program now has a new pattern option /B and a command line
147        option -b, which is equivalent to adding /B to every pattern. This causes
148        it to show the compiled bytecode, without the additional information that
149        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
150        is the same as /B/I).
152    23. A new optimization is now able automatically to treat some sequences such
153        as a*b as a*+b. More specifically, if something simple (such as a character
154        or a simple class like \d) has an unlimited quantifier, and is followed by
155        something that cannot possibly match the quantified thing, the quantifier
156        is automatically "possessified".
158    24. A recursive reference to a subpattern whose number was greater than 39
159        went wrong under certain circumstances in UTF-8 mode. This bug could also
160        have affected the operation of pcre_study().
162    25. Realized that a little bit of performance could be had by replacing
163        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
165    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
167    27. Possessive quantifiers such as a++ were previously implemented by turning
168        them into atomic groups such as ($>a+). Now they have their own opcodes,
169        which improves performance. This includes the automatically created ones
170        from 23 above.
172    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
173        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
174        the first matched character to be a colon. This applied both to named and
175        numbered groups.
177    29. The ucpinternal.h header file was missing its idempotency #ifdef.
179    30. I was sent a "project" file called libpcre.a.dev which I understand makes
180        building PCRE on Windows easier, so I have included it in the distribution.
182    31. There is now a check in pcretest against a ridiculously large number being
183        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
184        loop, the loop is abandoned.
186    32. Forward references to subpatterns in conditions such as (?(2)...) where
187        subpattern 2 is defined later cause pcre_compile() to search forwards in
188        the pattern for the relevant set of parentheses. This search went wrong
189        when there were unescaped parentheses in a character class, parentheses
190        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
192    33. "Subroutine" calls and backreferences were previously restricted to
193        referencing subpatterns earlier in the regex. This restriction has now
194        been removed.
196    34. Added a number of extra features that are going to be in Perl 5.10. On the
197        whole, these are just syntactic alternatives for features that PCRE had
198        previously implemented using the Python syntax or my own invention. The
199        other formats are all retained for compatibility.
201        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
202            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
203            also .NET compatible.
205        (b) A recursion or subroutine call to a named group can now be defined as
206            (?&name) as well as (?P>name).
208        (c) A backreference to a named group can now be defined as \k<name> or
209            \k'name' as well as (?P=name). The new forms, as well as being in Perl
210            5.10, are also .NET compatible.
212        (d) A conditional reference to a named group can now use the syntax
213            (?(<name>) or (?('name') as well as (?(name).
215        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
216            groups (named and numbered) that are never evaluated inline, but can be
217            called as "subroutines" from elsewhere. In effect, the DEFINE condition
218            is always false. There may be only one alternative in such a group.
220        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
221            as the simple (?(R). The condition is true only if the most recent
222            recursion is that of the given number or name. It does not search out
223            through the entire recursion stack.
225        (g) The escape \gN or \g{N} has been added, where N is a positive or
226            negative number, specifying an absolute or relative reference.
228    35. Tidied to get rid of some further signed/unsigned compiler warnings and
229        some "unreachable code" warnings.
231    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
232        things, this adds five new scripts.
234    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
235        There were also incompatibilities regarding the handling of \Q..\E inside
236        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
237        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
239    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
240        matches an empty string, and forcibly breaks the loop. There were bugs in
241        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
242        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
243        separate and independent bugs (that affected different cases) have been
244        fixed.
246    39. Refactored the code to abolish the use of different opcodes for small
247        capturing bracket numbers. This is a tidy that I avoided doing when I
248        removed the limit on the number of capturing brackets for 3.5 back in 2001.
249        The new approach is not only tidier, it makes it possible to reduce the
250        memory needed to fix the previous bug (38).
252    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
253        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
254        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
255        mode.
257    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
258        report.
260    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
261        copy construction and assignment in the C++ wrapper.
263    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
264        couple of bugs that could have given wrong results in the "--newline=crlf"
265        case.
267    44. Added a number of casts and did some reorganization of signed/unsigned int
268        variables following suggestions from Dair Grant. Also renamed the variable
269        "this" as "item" because it is a C++ keyword.
271    45. Arranged for dftables to add
273          #include "pcre_internal.h"
275        to pcre_chartables.c because without it, gcc 4.x may remove the array
276        definition from the final binary if PCRE is built into a static library and
277        dead code stripping is activated.
279    46. For an unanchored pattern, if a match attempt fails at the start of a
280        newline sequence, and the newline setting is CRLF or ANY, and the next two
281        characters are CRLF, advance by two characters instead of one.
284    Version 6.7 04-Jul-06
285    ---------------------
287     1. In order to handle tests when input lines are enormously long, pcretest has
288        been re-factored so that it automatically extends its buffers when
289        necessary. The code is crude, but this _is_ just a test program. The
290        default size has been increased from 32K to 50K.
292     2. The code in pcre_study() was using the value of the re argument before
293        testing it for NULL. (Of course, in any sensible call of the function, it
294        won't be NULL.)
296     3. The memmove() emulation function in pcre_internal.h, which is used on
297        systems that lack both memmove() and bcopy() - that is, hardly ever -
298        was missing a "static" storage class specifier.
300     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
301        containing an extended class (one that cannot be represented by a bitmap
302        because it contains high-valued characters or Unicode property items, e.g.
303        [\pZ]). Almost always one would set UTF-8 mode when processing such a
304        pattern, but PCRE should not loop if you do not (it no longer does).
305        [Detail: two cases were found: (a) a repeated subpattern containing an
306        extended class; (b) a recursive reference to a subpattern that followed a
307        previous extended class. It wasn't skipping over the extended class
308        correctly when UTF-8 mode was not set.]
310     5. A negated single-character class was not being recognized as fixed-length
311        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
312        compile error "lookbehind assertion is not fixed length".
314     6. The RunPerlTest auxiliary script was showing an unexpected difference
315        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
316        write a Perl script that can interpret lines of an input file either as
317        byte characters or as UTF-8, which is what "perltest" was being required to
318        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
319        can't do is switch easily at run time between having the "use utf8;" pragma
320        or not. In the end, I fudged it by using the RunPerlTest script to insert
321        "use utf8;" explicitly for the UTF-8 tests.
323     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
324        the end of the subject string, contrary to the documentation and to what
325        Perl does. This was true of both matching functions. Now it matches only at
326        the start of the subject and immediately after *internal* newlines.
328     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
329        a pointer to an int instead of a pointer to an unsigned long int. This
330        caused problems on 64-bit systems.
332     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
333        instance of the 'standard' template library not being so standard".
335    10. There was no check on the number of named subpatterns nor the maximum
336        length of a subpattern name. The product of these values is used to compute
337        the size of the memory block for a compiled pattern. By supplying a very
338        long subpattern name and a large number of named subpatterns, the size
339        computation could be caused to overflow. This is now prevented by limiting
340        the length of names to 32 characters, and the number of named subpatterns
341        to 10,000.
343    11. Subpatterns that are repeated with specific counts have to be replicated in
344        the compiled pattern. The size of memory for this was computed from the
345        length of the subpattern and the repeat count. The latter is limited to
346        65535, but there was no limit on the former, meaning that integer overflow
347        could in principle occur. The compiled length of a repeated subpattern is
348        now limited to 30,000 bytes in order to prevent this.
350    12. Added the optional facility to have named substrings with the same name.
352    13. Added the ability to use a named substring as a condition, using the
353        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
354        are numbers (not recommended). Forward references are permitted.
356    14. Added forward references in named backreferences (if you see what I mean).
358    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
359        pattern could run off the end of the subject. For example, the pattern
360        "(?s)(.{1,5})"8 did this with the subject "ab".
362    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
363        PCRE_CASELESS was set when matching characters that were quantified with ?
364        or *.
366    17. A character class other than a single negated character that had a minimum
367        but no maximum quantifier - for example [ab]{6,} - was not handled
368        correctly by pce_dfa_exec(). It would match only one character.
370    18. A valid (though odd) pattern that looked like a POSIX character
371        class but used an invalid character after [ (for example [[,abc,]]) caused
372        pcre_compile() to give the error "Failed: internal error: code overflow" or
373        in some cases to crash with a glibc free() error. This could even happen if
374        the pattern terminated after [[ but there just happened to be a sequence of
375        letters, a binary zero, and a closing ] in the memory that followed.
377    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
378        over the years. Originally (before any Unicode support), just the bottom 8
379        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
380        output from "man perlunicode" includes this:
382          The regular expression compiler produces polymorphic opcodes.  That
383          is, the pattern adapts to the data and automatically switches to
384          the Unicode character scheme when presented with Unicode data--or
385          instead uses a traditional byte scheme when presented with byte
386          data.
388        Sadly, a wide octal escape does not cause a switch, and in a string with
389        no other multibyte characters, these octal escapes are treated as before.
390        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
391        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
392        Unicode string.
394        I have not perpetrated such confusion in PCRE. Up till now, it took just
395        the bottom 8 bits, as in old Perl. I have now made octal escapes with
396        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
397        translate to the appropriate multibyte character.
399    29. Applied some refactoring to reduce the number of warnings from Microsoft
400        and Borland compilers. This has included removing the fudge introduced
401        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
402        a warning about an unused variable.
404    21. PCRE has not included VT (character 0x0b) in the set of whitespace
405        characters since release 4.0, because Perl (from release 5.004) does not.
406        [Or at least, is documented not to: some releases seem to be in conflict
407        with the documentation.] However, when a pattern was studied with
408        pcre_study() and all its branches started with \s, PCRE still included VT
409        as a possible starting character. Of course, this did no harm; it just
410        caused an unnecessary match attempt.
412    22. Removed a now-redundant internal flag bit that recorded the fact that case
413        dependency changed within the pattern. This was once needed for "required
414        byte" processing, but is no longer used. This recovers a now-scarce options
415        bit. Also moved the least significant internal flag bit to the most-
416        significant bit of the word, which was not previously used (hangover from
417        the days when it was an int rather than a uint) to free up another bit for
418        the future.
420    23. Added support for CRLF line endings as well as CR and LF. As well as the
421        default being selectable at build time, it can now be changed at runtime
422        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
423        specify that it is scanning data with non-default line endings.
425    24. Changed the definition of CXXLINK to make it agree with the definition of
426        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
428    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
429        recursions. This makes a big different to stack usage for some patterns.
431    26. If a subpattern containing a named recursion or subroutine reference such
432        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
433        the space required for the compiled pattern went wrong and gave too small a
434        value. Depending on the environment, this could lead to "Failed: internal
435        error: code overflow at offset 49" or "glibc detected double free or
436        corruption" errors.
438    27. Applied patches from Google (a) to support the new newline modes and (b) to
439        advance over multibyte UTF-8 characters in GlobalReplace.
441    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
442        difference for some implementation of PCRE in some Windows version.
444    29. Added some extra testing facilities to pcretest:
446        \q<number>   in a data line sets the "match limit" value
447        \Q<number>   in a data line sets the "match recursion limt" value
448        -S <number>  sets the stack size, where <number> is in megabytes
450        The -S option isn't available for Windows.
453    Version 6.6 06-Feb-06
454    ---------------------
456     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
457        in pcreposix.h. I have copied the definition from pcre.h.
459     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
460        because pcre.h is no longer a built file.
462     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
463        not normally included in the compiled code.
466    Version 6.5 01-Feb-06
467    ---------------------
469     1. When using the partial match feature with pcre_dfa_exec(), it was not
470        anchoring the second and subsequent partial matches at the new starting
471        point. This could lead to incorrect results. For example, with the pattern
472        /1234/, partially matching against "123" and then "a4" gave a match.
474     2. Changes to pcregrep:
476        (a) All non-match returns from pcre_exec() were being treated as failures
477            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
478            error message is output. Some extra information is given for the
479            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
480            probably the only errors that are likely to be caused by users (by
481            specifying a regex that has nested indefinite repeats, for instance).
482            If there are more than 20 of these errors, pcregrep is abandoned.
484        (b) A binary zero was treated as data while matching, but terminated the
485            output line if it was written out. This has been fixed: binary zeroes
486            are now no different to any other data bytes.
488        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
489            used to set a locale for matching. The --locale=xxxx long option has
490            been added (no short equivalent) to specify a locale explicitly on the
491            pcregrep command, overriding the environment variables.
493        (d) When -B was used with -n, some line numbers in the output were one less
494            than they should have been.
496        (e) Added the -o (--only-matching) option.
498        (f) If -A or -C was used with -c (count only), some lines of context were
499            accidentally printed for the final match.
501        (g) Added the -H (--with-filename) option.
503        (h) The combination of options -rh failed to suppress file names for files
504            that were found from directory arguments.
506        (i) Added the -D (--devices) and -d (--directories) options.
508        (j) Added the -F (--fixed-strings) option.
510        (k) Allow "-" to be used as a file name for -f as well as for a data file.
512        (l) Added the --colo(u)r option.
514        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
515            is not present by default.
517     3. A nasty bug was discovered in the handling of recursive patterns, that is,
518        items such as (?R) or (?1), when the recursion could match a number of
519        alternatives. If it matched one of the alternatives, but subsequently,
520        outside the recursion, there was a failure, the code tried to back up into
521        the recursion. However, because of the way PCRE is implemented, this is not
522        possible, and the result was an incorrect result from the match.
524        In order to prevent this happening, the specification of recursion has
525        been changed so that all such subpatterns are automatically treated as
526        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
528     4. I had overlooked the fact that, in some locales, there are characters for
529        which isalpha() is true but neither isupper() nor islower() are true. In
530        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
531        and ordfeminine) are like this. This affected the treatment of \w and \W
532        when they appeared in character classes, but not when they appeared outside
533        a character class. The bit map for "word" characters is now created
534        separately from the results of isalnum() instead of just taking it from the
535        upper, lower, and digit maps. (Plus the underscore character, of course.)
537     5. The above bug also affected the handling of POSIX character classes such as
538        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
539        permanent tables. Instead, the bit maps for such a class were previously
540        created as the appropriate unions of the upper, lower, and digit bitmaps.
541        Now they are created by subtraction from the [[:word:]] class, which has
542        its own bitmap.
544     6. The [[:blank:]] character class matches horizontal, but not vertical space.
545        It is created by subtracting the vertical space characters (\x09, \x0a,
546        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
547        subtraction was done in the overall bitmap for a character class, meaning
548        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
549        be recognized. This bug has been fixed.
551     7. Patches from the folks at Google:
553          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
554          real life, but is still worth protecting against".
556          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
557          regular expressions".
559          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
560          have it.
562          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
563          "configure" and the latter not, in order to fix a problem somebody had
564          with compiling the Arg class on HP-UX.
566          (e) Improve the error-handling of the C++ wrapper a little bit.
568          (f) New tests for checking recursion limiting.
570     8. The pcre_memmove() function, which is used only if the environment does not
571        have a standard memmove() function (and is therefore rarely compiled),
572        contained two bugs: (a) use of int instead of size_t, and (b) it was not
573        returning a result (though PCRE never actually uses the result).
575     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
576        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
577        returned instead of calling malloc() with an overflowing number that would
578        most likely cause subsequent chaos.
580    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
582    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
583        with this option is matched, the nmatch and pmatch options of regexec() are
584        ignored.
586    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
587        provided in case anyone wants to the the POSIX interface with UTF-8
588        strings.
590    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
591        C++ linking (needed for some HP-UX environments).
593    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
594        (unused parameter) and in the pcre_printint() function (omitted "default"
595        switch label when the default is to do nothing).
597    15. Added some code to make it possible, when PCRE is compiled as a C++
598        library, to replace subject pointers for pcre_exec() with a smart pointer
599        class, thus making it possible to process discontinuous strings.
601    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
602        much the same function. They were added by different people who were trying
603        to make PCRE easy to compile on non-Unix systems. It has been suggested
604        that PCRE_EXPORT be abolished now that there is more automatic apparatus
605        for compiling on Windows systems. I have therefore replaced it with
606        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
607        defaults to "extern" for C or "extern C" for C++, which works fine on
608        Unix-like systems. It is now possible to override the value of PCRE_DATA_
609        SCOPE with something explicit in config.h. In addition:
611        (a) pcreposix.h still had just "extern" instead of either of these macros;
612            I have replaced it with PCRE_DATA_SCOPE.
614        (b) Functions such as _pcre_xclass(), which are internal to the library,
615            but external in the C sense, all had PCRE_EXPORT in their definitions.
616            This is apparently wrong for the Windows case, so I have removed it.
617            (It makes no difference on Unix-like systems.)
619    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
620        of recursive calls to match(). This is different to MATCH_LIMIT because
621        that limits the total number of calls to match(), not all of which increase
622        the depth of recursion. Limiting the recursion depth limits the amount of
623        stack (or heap if NO_RECURSE is set) that is used. The default can be set
624        when PCRE is compiled, and changed at run time. A patch from Google adds
625        this functionality to the C++ interface.
627    18. Changes to the handling of Unicode character properties:
629        (a) Updated the table to Unicode 4.1.0.
631        (b) Recognize characters that are not in the table as "Cn" (undefined).
633        (c) I revised the way the table is implemented to a much improved format
634            which includes recognition of ranges. It now supports the ranges that
635            are defined in UnicodeData.txt, and it also amalgamates other
636            characters into ranges. This has reduced the number of entries in the
637            table from around 16,000 to around 3,000, thus reducing its size
638            considerably. I realized I did not need to use a tree structure after
639            all - a binary chop search is just as efficient. Having reduced the
640            number of entries, I extended their size from 6 bytes to 8 bytes to
641            allow for more data.
643        (d) Added support for Unicode script names via properties such as \p{Han}.
645    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
646        matching that character.
648    20. When matching a repeated Unicode property with a minimum greater than zero,
649        (for example \pL{2,}), PCRE could look past the end of the subject if it
650        reached it while seeking the minimum number of characters. This could
651        happen only if some of the characters were more than one byte long, because
652        there is a check for at least the minimum number of bytes.
654    21. Refactored the implementation of \p and \P so as to be more general, to
655        allow for more different types of property in future. This has changed the
656        compiled form incompatibly. Anybody with saved compiled patterns that use
657        \p or \P will have to recompile them.
659    22. Added "Any" and "L&" to the supported property types.
661    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
662        but give a compile time error if the value is greater than 0xff.
664    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
665        accidentally not being installed or uninstalled.
667    25. The pcre.h file was built from pcre.h.in, but the only changes that were
668        made were to insert the current release number. This seemed silly, because
669        it made things harder for people building PCRE on systems that don't run
670        "configure". I have turned pcre.h into a distributed file, no longer built
671        by "configure", with the version identification directly included. There is
672        no longer a pcre.h.in file.
674        However, this change necessitated a change to the pcre-config script as
675        well. It is built from pcre-config.in, and one of the substitutions was the
676        release number. I have updated configure.ac so that ./configure now finds
677        the release number by grepping pcre.h.
679    26. Added the ability to run the tests under valgrind.
682    Version 6.4 05-Sep-05
683    ---------------------
685     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
686        "--" to be printed when multiple files were scanned, even when none of the
687        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
688        consider it to be a bug, and have restored the previous behaviour.
690     2. A couple of code tidies to get rid of compiler warnings.
692     3. The pcretest program used to cheat by referring to symbols in the library
693        whose names begin with _pcre_. These are internal symbols that are not
694        really supposed to be visible externally, and in some environments it is
695        possible to suppress them. The cheating is now confined to including
696        certain files from the library's source, which is a bit cleaner.
698     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
699        file's purpose clearer.
701     5. Reorganized pcre_ucp_findchar().
704    Version 6.3 15-Aug-05
705    ---------------------
707     1. The file libpcre.pc.in did not have general read permission in the tarball.
709     2. There were some problems when building without C++ support:
711        (a) If C++ support was not built, "make install" and "make test" still
712            tried to test it.
714        (b) There were problems when the value of CXX was explicitly set. Some
715            changes have been made to try to fix these, and ...
717        (c) --disable-cpp can now be used to explicitly disable C++ support.
719        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
720            backslash in a target when C++ was disabled. This confuses some
721            versions of "make", apparently. Using an intermediate variable solves
722            this. (Same for CPP_LOBJ.)
724     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
725        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
726        necessary on certain architectures.
728     4. Added a setting of -export-symbols-regex to the link command to remove
729        those symbols that are exported in the C sense, but actually are local
730        within the library, and not documented. Their names all begin with
731        "_pcre_". This is not a perfect job, because (a) we have to except some
732        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
733        available (and never for static libraries). I have made a note to try to
734        find a way round (a) in the future.
737    Version 6.2 01-Aug-05
738    ---------------------
740     1. There was no test for integer overflow of quantifier values. A construction
741        such as {1111111111111111} would give undefined results. What is worse, if
742        a minimum quantifier for a parenthesized subpattern overflowed and became
743        negative, the calculation of the memory size went wrong. This could have
744        led to memory overwriting.
746     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
748     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
749        operating environments where this matters.
751     4. Applied Giuseppe Maxia's patch to add additional features for controlling
752        PCRE options from within the C++ wrapper.
754     5. Named capturing subpatterns were not being correctly counted when a pattern
755        was compiled. This caused two problems: (a) If there were more than 100
756        such subpatterns, the calculation of the memory needed for the whole
757        compiled pattern went wrong, leading to an overflow error. (b) Numerical
758        back references of the form \12, where the number was greater than 9, were
759        not recognized as back references, even though there were sufficient
760        previous subpatterns.
762     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
763        versions of gcc, e.g. 2.95.4.
766    Version 6.1 21-Jun-05
767    ---------------------
769     1. There was one reference to the variable "posix" in pcretest.c that was not
770        surrounded by "#if !defined NOPOSIX".
772     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
773        the cross-check on the old pcre_info() function, for the benefit of the
774        cut-down version of PCRE that is currently imported into Exim.
776     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
777        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
778        patterns that start (?i) but I don't think that matters. The use of (?i) is
779        just an example; this all applies to the other options as well.
781     4. Since libtool seems to echo the compile commands it is issuing, the output
782        from "make" can be reduced a bit by putting "@" in front of each libtool
783        compile command.
785     5. Patch from the folks at Google for configure.in to be a bit more thorough
786        in checking for a suitable C++ installation before trying to compile the
787        C++ stuff. This should fix a reported problem when a compiler was present,
788        but no suitable headers.
790     6. The man pages all had just "PCRE" as their title. I have changed them to
791        be the relevant file name. I have also arranged that these names are
792        retained in the file doc/pcre.txt, which is a concatenation in text format
793        of all the man pages except the little individual ones for each function.
795     7. The NON-UNIX-USE file had not been updated for the different set of source
796        files that come with release 6. I also added a few comments about the C++
797        wrapper.
800    Version 6.0 07-Jun-05
801    ---------------------
803     1. Some minor internal re-organization to help with my DFA experiments.
805     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
806        didn't matter for the library itself when fully configured, but did matter
807        when compiling without UCP support, or within Exim, where the ucp files are
808        not imported.
810     3. Refactoring of the library code to split up the various functions into
811        different source modules. The addition of the new DFA matching code (see
812        below) to a single monolithic source would have made it really too
813        unwieldy, quite apart from causing all the code to be include in a
814        statically linked application, when only some functions are used. This is
815        relevant even without the DFA addition now that patterns can be compiled in
816        one application and matched in another.
818        The downside of splitting up is that there have to be some external
819        functions and data tables that are used internally in different modules of
820        the library but which are not part of the API. These have all had their
821        names changed to start with "_pcre_" so that they are unlikely to clash
822        with other external names.
824     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
825        a different (DFA) algorithm. Although it is slower than the original
826        function, it does have some advantages for certain types of matching
827        problem.
829     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
830        including restarting after a partial match.
832     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
833        defined when compiling for Windows was sent to me. I have put it into the
834        code, though I have no means of testing or verifying it.
836     7. Added the pcre_refcount() auxiliary function.
838     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
839        match before or at the first newline in the subject string. In pcretest,
840        the /f option on a pattern can be used to set this.
842     9. A repeated \w when used in UTF-8 mode with characters greater than 256
843        would behave wrongly. This has been present in PCRE since release 4.0.
845    10. A number of changes to the pcregrep command:
847        (a) Refactored how -x works; insert ^(...)$ instead of setting
848            PCRE_ANCHORED and checking the length, in preparation for adding
849            something similar for -w.
851        (b) Added the -w (match as a word) option.
853        (c) Refactored the way lines are read and buffered so as to have more
854            than one at a time available.
856        (d) Implemented a pcregrep test script.
858        (e) Added the -M (multiline match) option. This allows patterns to match
859            over several lines of the subject. The buffering ensures that at least
860            8K, or the rest of the document (whichever is the shorter) is available
861            for matching (and similarly the previous 8K for lookbehind assertions).
863        (f) Changed the --help output so that it now says
865              -w, --word-regex(p)
867            instead of two lines, one with "regex" and the other with "regexp"
868            because that confused at least one person since the short forms are the
869            same. (This required a bit of code, as the output is generated
870            automatically from a table. It wasn't just a text change.)
872        (g) -- can be used to terminate pcregrep options if the next thing isn't an
873            option but starts with a hyphen. Could be a pattern or a path name
874            starting with a hyphen, for instance.
876        (h) "-" can be given as a file name to represent stdin.
878        (i) When file names are being printed, "(standard input)" is used for
879            the standard input, for compatibility with GNU grep. Previously
880            "<stdin>" was used.
882        (j) The option --label=xxx can be used to supply a name to be used for
883            stdin when file names are being printed. There is no short form.
885        (k) Re-factored the options decoding logic because we are going to add
886            two more options that take data. Such options can now be given in four
887            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
889        (l) Added the -A, -B, and -C options for requesting that lines of context
890            around matches be printed.
892        (m) Added the -L option to print the names of files that do not contain
893            any matching lines, that is, the complement of -l.
895        (n) The return code is 2 if any file cannot be opened, but pcregrep does
896            continue to scan other files.
898        (o) The -s option was incorrectly implemented. For compatibility with other
899            greps, it now suppresses the error message for a non-existent or non-
900            accessible file (but not the return code). There is a new option called
901            -q that suppresses the output of matching lines, which was what -s was
902            previously doing.
904        (p) Added --include and --exclude options to specify files for inclusion
905            and exclusion when recursing.
907    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
908        Hopefully, it now does.
910    12. Missing cast in pcre_study().
912    13. Added an "uninstall" target to the makefile.
914    14. Replaced "extern" in the function prototypes in Makefile.in with
915        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
916        world, but is set differently for Windows.
918    15. Added a second compiling function called pcre_compile2(). The only
919        difference is that it has an extra argument, which is a pointer to an
920        integer error code. When there is a compile-time failure, this is set
921        non-zero, in addition to the error test pointer being set to point to an
922        error message. The new argument may be NULL if no error number is required
923        (but then you may as well call pcre_compile(), which is now just a
924        wrapper). This facility is provided because some applications need a
925        numeric error indication, but it has also enabled me to tidy up the way
926        compile-time errors are handled in the POSIX wrapper.
928    16. Added VPATH=.libs to the makefile; this should help when building with one
929        prefix path and installing with another. (Or so I'm told by someone who
930        knows more about this stuff than I do.)
932    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
933        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
934        match everything, including newlines. This is not POSIX-compatible, but
935        somebody wanted the feature. From pcretest it can be activated by using
936        both the P and the s flags.
938    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
940    19. libpcre.pc was being incorrectly installed as executable.
942    20. A couple of places in pcretest check for end-of-line by looking for '\n';
943        it now also looks for '\r' so that it will work unmodified on Windows.
945    21. Added Google's contributed C++ wrapper to the distribution.
947    22. Added some untidy missing memory free() calls in pcretest, to keep
948        Electric Fence happy when testing.
952    Version 5.0 13-Sep-04
953    ---------------------
955     1. Internal change: literal characters are no longer packed up into items
956        containing multiple characters in a single byte-string. Each character
957        is now matched using a separate opcode. However, there may be more than one
958        byte in the character in UTF-8 mode.
960     2. The pcre_callout_block structure has two new fields: pattern_position and
961        next_item_length. These contain the offset in the pattern to the next match
962        item, and its length, respectively.
964     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
965        insertion of callouts before each pattern item. Added the /C option to
966        pcretest to make use of this.
968     4. On the advice of a Windows user, the lines
970          #if defined(_WIN32) || defined(WIN32)
971          _setmode( _fileno( stdout ), 0x8000 );
972          #endif  /* defined(_WIN32) || defined(WIN32) */
974        have been added to the source of pcretest. This apparently does useful
975        magic in relation to line terminators.
977     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
978        for the benefit of those environments where the "b" makes a difference.
980     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
981        to know about it. I have put a hack into configure.in that adds in code
982        to set GCC=yes if CC=icc. This seems to end up at a point in the
983        generated configure script that is early enough to affect the setting of
984        compiler options, which is what is needed, but I have no means of testing
985        whether it really works. (The user who reported this had patched the
986        generated configure script, which of course I cannot do.)
988        LATER: After change 22 below (new libtool files), the configure script
989        seems to know about icc (and also ecc). Therefore, I have commented out
990        this hack in configure.in.
992     7. Added support for pkg-config (2 patches were sent in).
994     8. Negated POSIX character classes that used a combination of internal tables
995        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
996        [[:^ascii]]. Typically, they would match almost any characters. The other
997        POSIX classes were not broken in this way.
999     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1000        to find the match, as PCRE was deluded into thinking that the match had to
1001        start at the start point or following a newline. The same bug applied to
1002        patterns with negative forward assertions or any backward assertions
1003        preceding ".*" at the start, unless the pattern required a fixed first
1004        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1006    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1007        starting at the last subject character, bytes beyond the end of the subject
1008        string were read.
1010    11. Renamed the variable "class" as "classbits" to make life easier for C++
1011        users. (Previously there was a macro definition, but it apparently wasn't
1012        enough.)
1014    12. Added the new field "tables" to the extra data so that tables can be passed
1015        in at exec time, or the internal tables can be re-selected. This allows
1016        a compiled regex to be saved and re-used at a later time by a different
1017        program that might have everything at different addresses.
1019    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1020        -R library as well as a -L library.
1022    14. The debugging options of pcretest (-d on the command line or D on a
1023        pattern) showed incorrect output for anything following an extended class
1024        that contained multibyte characters and which was followed by a quantifier.
1026    15. Added optional support for general category Unicode character properties
1027        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1028        support. It adds about 90K to the size of the library. The meanings of the
1029        inbuilt class escapes such as \d and \s have NOT been changed.
1031    16. Updated pcredemo.c to include calls to free() to release the memory for the
1032        compiled pattern.
1034    17. The generated file chartables.c was being created in the source directory
1035        instead of in the building directory. This caused the build to fail if the
1036        source directory was different from the building directory, and was
1037        read-only.
1039    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1040        file. No doubt somebody will tell me if they don't make sense... Also added
1041        Dan Mooney's comments about building on OpenVMS.
1043    19. Added support for partial matching via the PCRE_PARTIAL option for
1044        pcre_exec() and the \P data escape in pcretest.
1046    20. Extended pcretest with 3 new pattern features:
1048        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1049              write the compiled pattern to the file whose name is "rest-of-line".
1050              This is a straight binary dump of the data, with the saved pointer to
1051              the character tables forced to be NULL. The study data, if any, is
1052              written too. After writing, pcretest reads a new pattern.
1054        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1055              compiled pattern from the given file. There must not be any
1056              occurrences of "<" in the file name (pretty unlikely); if there are,
1057              pcretest will instead treat the initial "<" as a pattern delimiter.
1058              After reading in the pattern, pcretest goes on to read data lines as
1059              usual.
1061        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1062              and 16-bit fields in a compiled pattern, to simulate a pattern that
1063              was compiled on a host of opposite endianness.
1065    21. The pcre-exec() function can now cope with patterns that were compiled on
1066        hosts of opposite endianness, with this restriction:
1068          As for any compiled expression that is saved and used later, the tables
1069          pointer field cannot be preserved; the extra_data field in the arguments
1070          to pcre_exec() should be used to pass in a tables address if a value
1071          other than the default internal tables were used at compile time.
1073    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1074        now diagnosed as an error. Previously, most of the time, a negative number
1075        would have been treated as zero, but if in addition "ovector" was passed as
1076        NULL, a crash could occur.
1078    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1079        new versions from the libtool 1.5 distribution (the last one is a copy of
1080        a file called libtool.m4). This seems to have fixed the need to patch
1081        "configure" to support Darwin 1.3 (which I used to do). However, I still
1082        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1083        workstation).
1085    24. Changed the PCRE licence to be the more standard "BSD" licence.
1088    Version 4.5 01-Dec-03
1089    ---------------------
1091     1. There has been some re-arrangement of the code for the match() function so
1092        that it can be compiled in a version that does not call itself recursively.
1093        Instead, it keeps those local variables that need separate instances for
1094        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1095        needs to "recurse". Keeping track of where control must go is done by means
1096        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1097        hide most of the details from the main code, and operates only if
1098        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1099        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1100        operating.
1102        To make it easier for callers to provide specially tailored get/free
1103        functions for this usage, two new functions, pcre_stack_malloc, and
1104        pcre_stack_free, are used. They are always called in strict stacking order,
1105        and the size of block requested is always the same.
1107        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1108        PCRE has been compiled to use the stack or the heap for recursion. The
1109        -C option of pcretest uses this to show which version is compiled.
1111        A new data escape \S, is added to pcretest; it causes the amounts of store
1112        obtained and freed by both kinds of malloc/free at match time to be added
1113        to the output.
1115     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1116        what's available on my current Linux desktop machine.
1118     3. When matching a UTF-8 string, the test for a valid string at the start has
1119        been extended. If start_offset is not zero, PCRE now checks that it points
1120        to a byte that is the start of a UTF-8 character. If not, it returns
1121        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1122        this is necessary because there may be backward assertions in the pattern.
1123        When matching the same subject several times, it may save resources to use
1124        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1126     4. The code for checking the validity of UTF-8 strings has been tightened so
1127        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1128        containing "overlong sequences".
1130     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1131        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1132        should have been "&", but it just so happened that all the cases this let
1133        through by mistake were picked up later in the function.
1135     6. I had used a variable called "isblank" - this is a C99 function, causing
1136        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1138     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1139        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1140        so the version is shown; (c) stop "make test" echoing "./RunTest".
1142     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1144     9. The prototype for memmove() for systems that don't have it was using
1145        size_t, but the inclusion of the header that defines size_t was later. I've
1146        moved the #includes for the C headers earlier to avoid this.
1148    10. Added some adjustments to the code to make it easier to compiler on certain
1149        special systems:
1151          (a) Some "const" qualifiers were missing.
1152          (b) Added the macro EXPORT before all exported functions; by default this
1153              is defined to be empty.
1154          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1155              that it reads its output file name as an argument instead of writing
1156              to the standard output and assuming this can be redirected.
1158    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1159        class containing characters with values greater than 255, PCRE compilation
1160        went into a loop.
1162    12. A recursive reference to a subpattern that was within another subpattern
1163        that had a minimum quantifier of zero caused PCRE to crash. For example,
1164        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1165        recursion. If the recursively-called subpattern itself had a zero repeat,
1166        that was OK.
1168    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1169        buffer into which it was copied (for escape processing) was still set at
1170        1024, so long lines caused crashes.
1172    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1173        "internal error: code overflow...". This applied to any character class
1174        that was followed by a possessive quantifier.
1176    15. Modified the Makefile to add libpcre.la as a prerequisite for
1177        libpcreposix.la because I was told this is needed for a parallel build to
1178        work.
1180    16. If a pattern that contained .* following optional items at the start was
1181        studied, the wrong optimizing data was generated, leading to matching
1182        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1183        matching string must start with a or b or c. The correct conclusion for
1184        this pattern is that a match can start with any character.
1187    Version 4.4 13-Aug-03
1188    ---------------------
1190     1. In UTF-8 mode, a character class containing characters with values between
1191        127 and 255 was not handled correctly if the compiled pattern was studied.
1192        In fixing this, I have also improved the studying algorithm for such
1193        classes (slightly).
1195     2. Three internal functions had redundant arguments passed to them. Removal
1196        might give a very teeny performance improvement.
1198     3. Documentation bug: the value of the capture_top field in a callout is *one
1199        more than* the number of the hightest numbered captured substring.
1201     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1202        in incorrectly linking with a previously installed version. They now link
1203        explicitly with libpcre.la.
1205     5. configure.in no longer needs to recognize Cygwin specially.
1207     6. A problem in pcre.in for Windows platforms is fixed.
1209     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1210        pcretest, it used to include the size of the study block as part of its
1211        output. Unfortunately, the structure contains a field that has a different
1212        size on different hardware architectures. This meant that the tests that
1213        showed this size failed. As the block is currently always of a fixed size,
1214        this information isn't actually particularly useful in pcretest output, so
1215        I have just removed it.
1217     8. Three pre-processor statements accidentally did not start in column 1.
1218        Sadly, there are *still* compilers around that complain, even though
1219        standard C has not required this for well over a decade. Sigh.
1221     9. In pcretest, the code for checking callouts passed small integers in the
1222        callout_data field, which is a void * field. However, some picky compilers
1223        complained about the casts involved for this on 64-bit systems. Now
1224        pcretest passes the address of the small integer instead, which should get
1225        rid of the warnings.
1227    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1228        both compile and run time, and gives an error if an invalid UTF-8 sequence
1229        is found. There is a option for disabling this check in cases where the
1230        string is known to be correct and/or the maximum performance is wanted.
1232    11. In response to a bug report, I changed one line in Makefile.in from
1234            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1235        to
1236            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1238        to look similar to other lines, but I have no way of telling whether this
1239        is the right thing to do, as I do not use Windows. No doubt I'll get told
1240        if it's wrong...
1243  Version 4.3 21-May-03  Version 4.3 21-May-03
1244  ---------------------  ---------------------

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