--- code/trunk/ChangeLog	2007/02/24 21:38:49	27
+++ code/trunk/ChangeLog	2007/06/13 15:09:54	182
@@ -1,6 +1,2387 @@
 ChangeLog for PCRE
 ------------------
 
+Version 7.2 13-June-07
+---------------------
+
+ 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
+    which is apparently normally available under Windows.
+
+ 2. Re-jig the pcregrep tests with different newline settings in an attempt
+    to make them independent of the local environment's newline setting.
+
+ 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
+
+ 4. Some of the "internals" tests were previously cut out when the link size
+    was not 2, because the output contained actual offsets. The recent new
+    "Z" feature of pcretest means that these can be cut out, making the tests
+    usable with all link sizes.
+
+ 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
+    stack recursion. This gives a massive performance boost under BSD, but just
+    a small improvement under Linux. However, it saves one field in the frame
+    in all cases.
+
+ 6. Added more features from the forthcoming Perl 5.10:
+
+    (a) (?-n) (where n is a string of digits) is a relative subroutine or
+        recursion call. It refers to the nth most recently opened parentheses.
+
+    (b) (?+n) is also a relative subroutine call; it refers to the nth next
+        to be opened parentheses.
+
+    (c) Conditions that refer to capturing parentheses can be specified
+        relatively, for example, (?(-2)... or (?(+3)...
+
+    (d) \K resets the start of the current match so that everything before
+        is not part of it.
+
+    (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
+
+    (f) \g{name} is another synonym - part of Perl 5.10's unification of
+        reference syntax.
+
+    (g) (?| introduces a group in which the numbering of parentheses in each
+        alternative starts with the same number.
+
+    (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
+
+ 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
+    PCRE_INFO_JCHANGED.
+
+ 8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
+    terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
+    for detecting groups that can match an empty string.
+
+ 9. A pattern with a very large number of alternatives (more than several
+    hundred) was running out of internal workspace during the pre-compile
+    phase, where pcre_compile() figures out how much memory will be needed. A
+    bit of new cunning has reduced the workspace needed for groups with
+    alternatives. The 1000-alternative test pattern now uses 12 bytes of
+    workspace instead of running out of the 4096 that are available.
+
+10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
+
+11. Applied patch from Google to remove an optimization that didn't quite work.
+    The report of the bug said:
+
+      pcrecpp::RE("a*").FullMatch("aaa") matches, while
+      pcrecpp::RE("a*?").FullMatch("aaa") does not, and
+      pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
+
+
+Version 7.1 24-Apr-07
+---------------------
+
+ 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
+    that is more "standard", making use of automake and other Autotools. There
+    is some re-arrangement of the files and adjustment of comments consequent
+    on this.
+
+ 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
+    for recursive directory scanning broke on some systems because the files
+    are not scanned in any specific order and on different systems the order
+    was different. A call to "sort" has been inserted into RunGrepTest for the
+    approprate test as a short-term fix. In the longer term there may be an
+    alternative.
+
+ 3. I had an email from Eric Raymond about problems translating some of PCRE's
+    man pages to HTML (despite the fact that I distribute HTML pages, some
+    people do their own conversions for various reasons). The problems
+    concerned the use of low-level troff macros .br and .in. I have therefore
+    removed all such uses from the man pages (some were redundant, some could
+    be replaced by .nf/.fi pairs). The 132html script that I use to generate
+    HTML has been updated to handle .nf/.fi and to complain if it encounters
+    .br or .in.
+
+ 4. Updated comments in configure.ac that get placed in config.h.in and also
+    arranged for config.h to be included in the distribution, with the name
+    config.h.generic, for the benefit of those who have to compile without
+    Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
+
+ 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
+    Weber: (1) pcre_internal.h was missing some function renames; (2) updated
+    makevp.bat for the current PCRE, using the additional files
+    makevp_c.txt, makevp_l.txt, and pcregexp.pas.
+
+ 6. A Windows user reported a minor discrepancy with test 2, which turned out
+    to be caused by a trailing space on an input line that had got lost in his
+    copy. The trailing space was an accident, so I've just removed it.
+
+ 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
+    that is needed.
+
+ 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
+    as "const" (a) because they are and (b) because it helps the PHP
+    maintainers who have recently made a script to detect big data structures
+    in the php code that should be moved to the .rodata section. I remembered
+    to update Builducptable as well, so it won't revert if ucptable.h is ever
+    re-created.
+
+ 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
+    pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
+    order to be able to cut out the UTF-8 tables in the latter when UTF-8
+    support is not required. This saves 1.5-2K of code, which is important in
+    some applications.
+
+    Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
+    so as not to refer to the tables, even though these functions will never be
+    called when UTF-8 support is disabled. Otherwise there are problems with a
+    shared library.
+
+10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
+
+    (a) It was defining its arguments as char * instead of void *.
+
+    (b) It was assuming that all moves were upwards in memory; this was true
+        a long time ago when I wrote it, but is no longer the case.
+
+    The emulated memove() is provided for those environments that have neither
+    memmove() nor bcopy(). I didn't think anyone used it these days, but that
+    is clearly not the case, as these two bugs were recently reported.
+
+11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
+    and Detrail to create the HTML documentation, the .txt form of the man
+    pages, and it removes trailing spaces from listed files. It also creates
+    pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
+    case, it wraps all the #defines with #ifndefs. This script should be run
+    before "make dist".
+
+12. Fixed two fairly obscure bugs concerned with quantified caseless matching
+    with Unicode property support.
+
+    (a) For a maximizing quantifier, if the two different cases of the
+        character were of different lengths in their UTF-8 codings (there are
+        some cases like this - I found 11), and the matching function had to
+        back up over a mixture of the two cases, it incorrectly assumed they
+        were both the same length.
+
+    (b) When PCRE was configured to use the heap rather than the stack for
+        recursion during matching, it was not correctly preserving the data for
+        the other case of a UTF-8 character when checking ahead for a match
+        while processing a minimizing repeat. If the check also involved
+        matching a wide character, but failed, corruption could cause an
+        erroneous result when trying to check for a repeat of the original
+        character.
+
+13. Some tidying changes to the testing mechanism:
+
+    (a) The RunTest script now detects the internal link size and whether there
+        is UTF-8 and UCP support by running ./pcretest -C instead of relying on
+        values substituted by "configure". (The RunGrepTest script already did
+        this for UTF-8.) The configure.ac script no longer substitutes the
+        relevant variables.
+
+    (b) The debugging options /B and /D in pcretest show the compiled bytecode
+        with length and offset values. This means that the output is different
+        for different internal link sizes. Test 2 is skipped for link sizes
+        other than 2 because of this, bypassing the problem. Unfortunately,
+        there was also a test in test 3 (the locale tests) that used /B and
+        failed for link sizes other than 2. Rather than cut the whole test out,
+        I have added a new /Z option to pcretest that replaces the length and
+        offset values with spaces. This is now used to make test 3 independent
+        of link size. (Test 2 will be tidied up later.)
+
+14. If erroroffset was passed as NULL to pcre_compile, it provoked a
+    segmentation fault instead of returning the appropriate error message.
+
+15. In multiline mode when the newline sequence was set to "any", the pattern
+    ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
+    This doesn't seem right; it now treats the CRLF combination as the line
+    ending, and so does not match in that case. It's only a pattern such as ^$
+    that would hit this one: something like ^ABC$ would have failed after \r
+    and then tried again after \r\n.
+
+16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
+    in an attempt to make files that differ only in their line terminators
+    compare equal. This works on Linux.
+
+17. Under certain error circumstances pcregrep might try to free random memory
+    as it exited. This is now fixed, thanks to valgrind.
+
+19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
+    "abc\r\n\r\n", it found an unwanted second match after the second \r. This
+    was because its rules for how to advance for /g after matching an empty
+    string at the end of a line did not allow for this case. They now check for
+    it specially.
+
+20. pcretest is supposed to handle patterns and data of any length, by
+    extending its buffers when necessary. It was getting this wrong when the
+    buffer for a data line had to be extended.
+
+21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
+    CRLF as a newline sequence.
+
+22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
+    out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
+    I have nevertheless tidied it up.
+
+23. Added some casts to kill warnings from HP-UX ia64 compiler.
+
+24. Added a man page for pcre-config.
+
+
+Version 7.0 19-Dec-06
+---------------------
+
+ 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
+    moving to gcc 4.1.1.
+
+ 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
+    sys/time.h, which is documented as needed for this function. It doesn't
+    seem to matter on Linux, but it showed up on some releases of OS X.
+
+ 3. It seems that there are systems where bytes whose values are greater than
+    127 match isprint() in the "C" locale. The "C" locale should be the
+    default when a C program starts up. In most systems, only ASCII printing
+    characters match isprint(). This difference caused the output from pcretest
+    to vary, making some of the tests fail. I have changed pcretest so that:
+
+    (a) When it is outputting text in the compiled version of a pattern, bytes
+        other than 32-126 are always shown as hex escapes.
+
+    (b) When it is outputting text that is a matched part of a subject string,
+        it does the same, unless a different locale has been set for the match
+        (using the /L modifier). In this case, it uses isprint() to decide.
+
+ 4. Fixed a major bug that caused incorrect computation of the amount of memory
+    required for a compiled pattern when options that changed within the
+    pattern affected the logic of the preliminary scan that determines the
+    length. The relevant options are -x, and -i in UTF-8 mode. The result was
+    that the computed length was too small. The symptoms of this bug were
+    either the PCRE error "internal error: code overflow" from pcre_compile(),
+    or a glibc crash with a message such as "pcretest: free(): invalid next
+    size (fast)". Examples of patterns that provoked this bug (shown in
+    pcretest format) are:
+
+      /(?-x: )/x
+      /(?x)(?-x: \s*#\s*)/
+      /((?i)[\x{c0}])/8
+      /(?i:[\x{c0}])/8
+
+    HOWEVER: Change 17 below makes this fix obsolete as the memory computation
+    is now done differently.
+
+ 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
+    wrapper classes; (b) implement a new function in the C++ scanner that is
+    more efficient than the old way of doing things because it avoids levels of
+    recursion in the regex matching; (c) add a paragraph to the documentation
+    for the FullMatch() function.
+
+ 6. The escape sequence \n was being treated as whatever was defined as
+    "newline". Not only was this contrary to the documentation, which states
+    that \n is character 10 (hex 0A), but it also went horribly wrong when
+    "newline" was defined as CRLF. This has been fixed.
+
+ 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
+    was being set to -1 for the "end of line" case (supposedly a value that no
+    character can have). Though this value is never used (the check for end of
+    line is "zero bytes in current character"), it caused compiler complaints.
+    I've changed it to 0xffffffff.
+
+ 8. In pcre_version.c, the version string was being built by a sequence of
+    C macros that, in the event of PCRE_PRERELEASE being defined as an empty
+    string (as it is for production releases) called a macro with an empty
+    argument. The C standard says the result of this is undefined. The gcc
+    compiler treats it as an empty string (which was what was wanted) but it is
+    reported that Visual C gives an error. The source has been hacked around to
+    avoid this problem.
+
+ 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
+    builds of pcretest, and changed the call to _setmode() to use _O_BINARY
+    instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
+    of them did).
+
+10. Originally, pcretest opened its input and output without "b"; then I was
+    told that "b" was needed in some environments, so it was added for release
+    5.0 to both the input and output. (It makes no difference on Unix-like
+    systems.) Later I was told that it is wrong for the input on Windows. I've
+    now abstracted the modes into two macros, to make it easier to fiddle with
+    them, and removed "b" from the input mode under Windows.
+
+11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
+
+12. Added -help and --help to pcretest as an official way of being reminded
+    of the options.
+
+13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
+    and pcrecpp.cc because they annoy compilers at high warning levels.
+
+14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
+
+15. Fixed an occurrence of == in configure.ac that should have been = (shell
+    scripts are not C programs :-) and which was not noticed because it works
+    on Linux.
+
+16. pcretest is supposed to handle any length of pattern and data line (as one
+    line or as a continued sequence of lines) by extending its input buffer if
+    necessary. This feature was broken for very long pattern lines, leading to
+    a string of junk being passed to pcre_compile() if the pattern was longer
+    than about 50K.
+
+17. I have done a major re-factoring of the way pcre_compile() computes the
+    amount of memory needed for a compiled pattern. Previously, there was code
+    that made a preliminary scan of the pattern in order to do this. That was
+    OK when PCRE was new, but as the facilities have expanded, it has become
+    harder and harder to keep it in step with the real compile phase, and there
+    have been a number of bugs (see for example, 4 above). I have now found a
+    cunning way of running the real compile function in a "fake" mode that
+    enables it to compute how much memory it would need, while actually only
+    ever using a few hundred bytes of working memory and without too many
+    tests of the mode. This should make future maintenance and development
+    easier. A side effect of this work is that the limit of 200 on the nesting
+    depth of parentheses has been removed (though this was never a serious
+    limitation, I suspect). However, there is a downside: pcre_compile() now
+    runs more slowly than before (30% or more, depending on the pattern). I
+    hope this isn't a big issue. There is no effect on runtime performance.
+
+18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
+    newline (only possible for the last line of a file) and it was a
+    pattern that set a locale (followed by /Lsomething), pcretest crashed.
+
+19. Added additional timing features to pcretest. (1) The -tm option now times
+    matching only, not compiling. (2) Both -t and -tm can be followed, as a
+    separate command line item, by a number that specifies the number of
+    repeats to use when timing. The default is 50000; this gives better
+    precision, but takes uncomfortably long for very large patterns.
+
+20. Extended pcre_study() to be more clever in cases where a branch of a
+    subpattern has no definite first character. For example, (a*|b*)[cd] would
+    previously give no result from pcre_study(). Now it recognizes that the
+    first character must be a, b, c, or d.
+
+21. There was an incorrect error "recursive call could loop indefinitely" if
+    a subpattern (or the entire pattern) that was being tested for matching an
+    empty string contained only one non-empty item after a nested subpattern.
+    For example, the pattern (?>\x{100}*)\d(?R) provoked this error
+    incorrectly, because the \d was being skipped in the check.
+
+22. The pcretest program now has a new pattern option /B and a command line
+    option -b, which is equivalent to adding /B to every pattern. This causes
+    it to show the compiled bytecode, without the additional information that
+    -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
+    is the same as /B/I).
+
+23. A new optimization is now able automatically to treat some sequences such
+    as a*b as a*+b. More specifically, if something simple (such as a character
+    or a simple class like \d) has an unlimited quantifier, and is followed by
+    something that cannot possibly match the quantified thing, the quantifier
+    is automatically "possessified".
+
+24. A recursive reference to a subpattern whose number was greater than 39
+    went wrong under certain circumstances in UTF-8 mode. This bug could also
+    have affected the operation of pcre_study().
+
+25. Realized that a little bit of performance could be had by replacing
+    (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
+
+26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
+
+27. Possessive quantifiers such as a++ were previously implemented by turning
+    them into atomic groups such as ($>a+). Now they have their own opcodes,
+    which improves performance. This includes the automatically created ones
+    from 23 above.
+
+28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
+    lookahead was broken if it was not anchored. PCRE was mistakenly expecting
+    the first matched character to be a colon. This applied both to named and
+    numbered groups.
+
+29. The ucpinternal.h header file was missing its idempotency #ifdef.
+
+30. I was sent a "project" file called libpcre.a.dev which I understand makes
+    building PCRE on Windows easier, so I have included it in the distribution.
+
+31. There is now a check in pcretest against a ridiculously large number being
+    returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
+    loop, the loop is abandoned.
+
+32. Forward references to subpatterns in conditions such as (?(2)...) where
+    subpattern 2 is defined later cause pcre_compile() to search forwards in
+    the pattern for the relevant set of parentheses. This search went wrong
+    when there were unescaped parentheses in a character class, parentheses
+    escaped with \Q...\E, or parentheses in a #-comment in /x mode.
+
+33. "Subroutine" calls and backreferences were previously restricted to
+    referencing subpatterns earlier in the regex. This restriction has now
+    been removed.
+
+34. Added a number of extra features that are going to be in Perl 5.10. On the
+    whole, these are just syntactic alternatives for features that PCRE had
+    previously implemented using the Python syntax or my own invention. The
+    other formats are all retained for compatibility.
+
+    (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
+        as (?P<name>...). The new forms, as well as being in Perl 5.10, are
+        also .NET compatible.
+
+    (b) A recursion or subroutine call to a named group can now be defined as
+        (?&name) as well as (?P>name).
+
+    (c) A backreference to a named group can now be defined as \k<name> or
+        \k'name' as well as (?P=name). The new forms, as well as being in Perl
+        5.10, are also .NET compatible.
+
+    (d) A conditional reference to a named group can now use the syntax
+        (?(<name>) or (?('name') as well as (?(name).
+
+    (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
+        groups (named and numbered) that are never evaluated inline, but can be
+        called as "subroutines" from elsewhere. In effect, the DEFINE condition
+        is always false. There may be only one alternative in such a group.
+
+    (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
+        as the simple (?(R). The condition is true only if the most recent
+        recursion is that of the given number or name. It does not search out
+        through the entire recursion stack.
+
+    (g) The escape \gN or \g{N} has been added, where N is a positive or
+        negative number, specifying an absolute or relative reference.
+
+35. Tidied to get rid of some further signed/unsigned compiler warnings and
+    some "unreachable code" warnings.
+
+36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
+    things, this adds five new scripts.
+
+37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
+    There were also incompatibilities regarding the handling of \Q..\E inside
+    character classes, for example with patterns like [\Qa\E-\Qz\E] where the
+    hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
+
+38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
+    matches an empty string, and forcibly breaks the loop. There were bugs in
+    this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
+    against  aaaa  the result was just "a" rather than "aaaa", for example. Two
+    separate and independent bugs (that affected different cases) have been
+    fixed.
+
+39. Refactored the code to abolish the use of different opcodes for small
+    capturing bracket numbers. This is a tidy that I avoided doing when I
+    removed the limit on the number of capturing brackets for 3.5 back in 2001.
+    The new approach is not only tidier, it makes it possible to reduce the
+    memory needed to fix the previous bug (38).
+
+40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
+    sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
+    processing dot, circumflex, or dollar metacharacters, or #-comments in /x
+    mode.
+
+41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
+    report.
+
+42. Applied patch, originally from Ari Pollak, modified by Google, to allow
+    copy construction and assignment in the C++ wrapper.
+
+43. Updated pcregrep to support "--newline=any". In the process, I fixed a
+    couple of bugs that could have given wrong results in the "--newline=crlf"
+    case.
+
+44. Added a number of casts and did some reorganization of signed/unsigned int
+    variables following suggestions from Dair Grant. Also renamed the variable
+    "this" as "item" because it is a C++ keyword.
+
+45. Arranged for dftables to add
+
+      #include "pcre_internal.h"
+
+    to pcre_chartables.c because without it, gcc 4.x may remove the array
+    definition from the final binary if PCRE is built into a static library and
+    dead code stripping is activated.
+
+46. For an unanchored pattern, if a match attempt fails at the start of a
+    newline sequence, and the newline setting is CRLF or ANY, and the next two
+    characters are CRLF, advance by two characters instead of one.
+
+
+Version 6.7 04-Jul-06
+---------------------
+
+ 1. In order to handle tests when input lines are enormously long, pcretest has
+    been re-factored so that it automatically extends its buffers when
+    necessary. The code is crude, but this _is_ just a test program. The
+    default size has been increased from 32K to 50K.
+
+ 2. The code in pcre_study() was using the value of the re argument before
+    testing it for NULL. (Of course, in any sensible call of the function, it
+    won't be NULL.)
+
+ 3. The memmove() emulation function in pcre_internal.h, which is used on
+    systems that lack both memmove() and bcopy() - that is, hardly ever -
+    was missing a "static" storage class specifier.
+
+ 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
+    containing an extended class (one that cannot be represented by a bitmap
+    because it contains high-valued characters or Unicode property items, e.g.
+    [\pZ]). Almost always one would set UTF-8 mode when processing such a
+    pattern, but PCRE should not loop if you do not (it no longer does).
+    [Detail: two cases were found: (a) a repeated subpattern containing an
+    extended class; (b) a recursive reference to a subpattern that followed a
+    previous extended class. It wasn't skipping over the extended class
+    correctly when UTF-8 mode was not set.]
+
+ 5. A negated single-character class was not being recognized as fixed-length
+    in lookbehind assertions such as (?<=[^f]), leading to an incorrect
+    compile error "lookbehind assertion is not fixed length".
+
+ 6. The RunPerlTest auxiliary script was showing an unexpected difference
+    between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
+    write a Perl script that can interpret lines of an input file either as
+    byte characters or as UTF-8, which is what "perltest" was being required to
+    do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
+    can't do is switch easily at run time between having the "use utf8;" pragma
+    or not. In the end, I fudged it by using the RunPerlTest script to insert
+    "use utf8;" explicitly for the UTF-8 tests.
+
+ 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
+    the end of the subject string, contrary to the documentation and to what
+    Perl does. This was true of both matching functions. Now it matches only at
+    the start of the subject and immediately after *internal* newlines.
+
+ 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
+    a pointer to an int instead of a pointer to an unsigned long int. This
+    caused problems on 64-bit systems.
+
+ 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
+    instance of the 'standard' template library not being so standard".
+
+10. There was no check on the number of named subpatterns nor the maximum
+    length of a subpattern name. The product of these values is used to compute
+    the size of the memory block for a compiled pattern. By supplying a very
+    long subpattern name and a large number of named subpatterns, the size
+    computation could be caused to overflow. This is now prevented by limiting
+    the length of names to 32 characters, and the number of named subpatterns
+    to 10,000.
+
+11. Subpatterns that are repeated with specific counts have to be replicated in
+    the compiled pattern. The size of memory for this was computed from the
+    length of the subpattern and the repeat count. The latter is limited to
+    65535, but there was no limit on the former, meaning that integer overflow
+    could in principle occur. The compiled length of a repeated subpattern is
+    now limited to 30,000 bytes in order to prevent this.
+
+12. Added the optional facility to have named substrings with the same name.
+
+13. Added the ability to use a named substring as a condition, using the
+    Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
+    are numbers (not recommended). Forward references are permitted.
+
+14. Added forward references in named backreferences (if you see what I mean).
+
+15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
+    pattern could run off the end of the subject. For example, the pattern
+    "(?s)(.{1,5})"8 did this with the subject "ab".
+
+16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
+    PCRE_CASELESS was set when matching characters that were quantified with ?
+    or *.
+
+17. A character class other than a single negated character that had a minimum
+    but no maximum quantifier - for example [ab]{6,} - was not handled
+    correctly by pce_dfa_exec(). It would match only one character.
+
+18. A valid (though odd) pattern that looked like a POSIX character
+    class but used an invalid character after [ (for example [[,abc,]]) caused
+    pcre_compile() to give the error "Failed: internal error: code overflow" or
+    in some cases to crash with a glibc free() error. This could even happen if
+    the pattern terminated after [[ but there just happened to be a sequence of
+    letters, a binary zero, and a closing ] in the memory that followed.
+
+19. Perl's treatment of octal escapes in the range \400 to \777 has changed
+    over the years. Originally (before any Unicode support), just the bottom 8
+    bits were taken. Thus, for example, \500 really meant \100. Nowadays the
+    output from "man perlunicode" includes this:
+
+      The regular expression compiler produces polymorphic opcodes.  That
+      is, the pattern adapts to the data and automatically switches to
+      the Unicode character scheme when presented with Unicode data--or
+      instead uses a traditional byte scheme when presented with byte
+      data.
+
+    Sadly, a wide octal escape does not cause a switch, and in a string with
+    no other multibyte characters, these octal escapes are treated as before.
+    Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
+    /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
+    Unicode string.
+
+    I have not perpetrated such confusion in PCRE. Up till now, it took just
+    the bottom 8 bits, as in old Perl. I have now made octal escapes with
+    values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
+    translate to the appropriate multibyte character.
+
+29. Applied some refactoring to reduce the number of warnings from Microsoft
+    and Borland compilers. This has included removing the fudge introduced
+    seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
+    a warning about an unused variable.
+
+21. PCRE has not included VT (character 0x0b) in the set of whitespace
+    characters since release 4.0, because Perl (from release 5.004) does not.
+    [Or at least, is documented not to: some releases seem to be in conflict
+    with the documentation.] However, when a pattern was studied with
+    pcre_study() and all its branches started with \s, PCRE still included VT
+    as a possible starting character. Of course, this did no harm; it just
+    caused an unnecessary match attempt.
+
+22. Removed a now-redundant internal flag bit that recorded the fact that case
+    dependency changed within the pattern. This was once needed for "required
+    byte" processing, but is no longer used. This recovers a now-scarce options
+    bit. Also moved the least significant internal flag bit to the most-
+    significant bit of the word, which was not previously used (hangover from
+    the days when it was an int rather than a uint) to free up another bit for
+    the future.
+
+23. Added support for CRLF line endings as well as CR and LF. As well as the
+    default being selectable at build time, it can now be changed at runtime
+    via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
+    specify that it is scanning data with non-default line endings.
+
+24. Changed the definition of CXXLINK to make it agree with the definition of
+    LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
+
+25. Applied Ian Taylor's patches to avoid using another stack frame for tail
+    recursions. This makes a big different to stack usage for some patterns.
+
+26. If a subpattern containing a named recursion or subroutine reference such
+    as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
+    the space required for the compiled pattern went wrong and gave too small a
+    value. Depending on the environment, this could lead to "Failed: internal
+    error: code overflow at offset 49" or "glibc detected double free or
+    corruption" errors.
+
+27. Applied patches from Google (a) to support the new newline modes and (b) to
+    advance over multibyte UTF-8 characters in GlobalReplace.
+
+28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
+    difference for some implementation of PCRE in some Windows version.
+
+29. Added some extra testing facilities to pcretest:
+
+    \q<number>   in a data line sets the "match limit" value
+    \Q<number>   in a data line sets the "match recursion limt" value
+    -S <number>  sets the stack size, where <number> is in megabytes
+
+    The -S option isn't available for Windows.
+
+
+Version 6.6 06-Feb-06
+---------------------
+
+ 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
+    in pcreposix.h. I have copied the definition from pcre.h.
+
+ 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
+    because pcre.h is no longer a built file.
+
+ 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
+    not normally included in the compiled code.
+
+
+Version 6.5 01-Feb-06
+---------------------
+
+ 1. When using the partial match feature with pcre_dfa_exec(), it was not
+    anchoring the second and subsequent partial matches at the new starting
+    point. This could lead to incorrect results. For example, with the pattern
+    /1234/, partially matching against "123" and then "a4" gave a match.
+
+ 2. Changes to pcregrep:
+
+    (a) All non-match returns from pcre_exec() were being treated as failures
+        to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
+        error message is output. Some extra information is given for the
+        PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
+        probably the only errors that are likely to be caused by users (by
+        specifying a regex that has nested indefinite repeats, for instance).
+        If there are more than 20 of these errors, pcregrep is abandoned.
+
+    (b) A binary zero was treated as data while matching, but terminated the
+        output line if it was written out. This has been fixed: binary zeroes
+        are now no different to any other data bytes.
+
+    (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
+        used to set a locale for matching. The --locale=xxxx long option has
+        been added (no short equivalent) to specify a locale explicitly on the
+        pcregrep command, overriding the environment variables.
+
+    (d) When -B was used with -n, some line numbers in the output were one less
+        than they should have been.
+
+    (e) Added the -o (--only-matching) option.
+
+    (f) If -A or -C was used with -c (count only), some lines of context were
+        accidentally printed for the final match.
+
+    (g) Added the -H (--with-filename) option.
+
+    (h) The combination of options -rh failed to suppress file names for files
+        that were found from directory arguments.
+
+    (i) Added the -D (--devices) and -d (--directories) options.
+
+    (j) Added the -F (--fixed-strings) option.
+
+    (k) Allow "-" to be used as a file name for -f as well as for a data file.
+
+    (l) Added the --colo(u)r option.
+
+    (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
+        is not present by default.
+
+ 3. A nasty bug was discovered in the handling of recursive patterns, that is,
+    items such as (?R) or (?1), when the recursion could match a number of
+    alternatives. If it matched one of the alternatives, but subsequently,
+    outside the recursion, there was a failure, the code tried to back up into
+    the recursion. However, because of the way PCRE is implemented, this is not
+    possible, and the result was an incorrect result from the match.
+
+    In order to prevent this happening, the specification of recursion has
+    been changed so that all such subpatterns are automatically treated as
+    atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
+
+ 4. I had overlooked the fact that, in some locales, there are characters for
+    which isalpha() is true but neither isupper() nor islower() are true. In
+    the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
+    and ordfeminine) are like this. This affected the treatment of \w and \W
+    when they appeared in character classes, but not when they appeared outside
+    a character class. The bit map for "word" characters is now created
+    separately from the results of isalnum() instead of just taking it from the
+    upper, lower, and digit maps. (Plus the underscore character, of course.)
+
+ 5. The above bug also affected the handling of POSIX character classes such as
+    [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
+    permanent tables. Instead, the bit maps for such a class were previously
+    created as the appropriate unions of the upper, lower, and digit bitmaps.
+    Now they are created by subtraction from the [[:word:]] class, which has
+    its own bitmap.
+
+ 6. The [[:blank:]] character class matches horizontal, but not vertical space.
+    It is created by subtracting the vertical space characters (\x09, \x0a,
+    \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
+    subtraction was done in the overall bitmap for a character class, meaning
+    that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
+    be recognized. This bug has been fixed.
+
+ 7. Patches from the folks at Google:
+
+      (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
+      real life, but is still worth protecting against".
+
+      (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
+      regular expressions".
+
+      (c) pcre_scanner.cc: avoid use of std::count() because not all systems
+      have it.
+
+      (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
+      "configure" and the latter not, in order to fix a problem somebody had
+      with compiling the Arg class on HP-UX.
+
+      (e) Improve the error-handling of the C++ wrapper a little bit.
+
+      (f) New tests for checking recursion limiting.
+
+ 8. The pcre_memmove() function, which is used only if the environment does not
+    have a standard memmove() function (and is therefore rarely compiled),
+    contained two bugs: (a) use of int instead of size_t, and (b) it was not
+    returning a result (though PCRE never actually uses the result).
+
+ 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
+    large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
+    returned instead of calling malloc() with an overflowing number that would
+    most likely cause subsequent chaos.
+
+10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
+
+11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
+    with this option is matched, the nmatch and pmatch options of regexec() are
+    ignored.
+
+12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
+    provided in case anyone wants to the the POSIX interface with UTF-8
+    strings.
+
+13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
+    C++ linking (needed for some HP-UX environments).
+
+14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
+    (unused parameter) and in the pcre_printint() function (omitted "default"
+    switch label when the default is to do nothing).
+
+15. Added some code to make it possible, when PCRE is compiled as a C++
+    library, to replace subject pointers for pcre_exec() with a smart pointer
+    class, thus making it possible to process discontinuous strings.
+
+16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
+    much the same function. They were added by different people who were trying
+    to make PCRE easy to compile on non-Unix systems. It has been suggested
+    that PCRE_EXPORT be abolished now that there is more automatic apparatus
+    for compiling on Windows systems. I have therefore replaced it with
+    PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
+    defaults to "extern" for C or "extern C" for C++, which works fine on
+    Unix-like systems. It is now possible to override the value of PCRE_DATA_
+    SCOPE with something explicit in config.h. In addition:
+
+    (a) pcreposix.h still had just "extern" instead of either of these macros;
+        I have replaced it with PCRE_DATA_SCOPE.
+
+    (b) Functions such as _pcre_xclass(), which are internal to the library,
+        but external in the C sense, all had PCRE_EXPORT in their definitions.
+        This is apparently wrong for the Windows case, so I have removed it.
+        (It makes no difference on Unix-like systems.)
+
+17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
+    of recursive calls to match(). This is different to MATCH_LIMIT because
+    that limits the total number of calls to match(), not all of which increase
+    the depth of recursion. Limiting the recursion depth limits the amount of
+    stack (or heap if NO_RECURSE is set) that is used. The default can be set
+    when PCRE is compiled, and changed at run time. A patch from Google adds
+    this functionality to the C++ interface.
+
+18. Changes to the handling of Unicode character properties:
+
+    (a) Updated the table to Unicode 4.1.0.
+
+    (b) Recognize characters that are not in the table as "Cn" (undefined).
+
+    (c) I revised the way the table is implemented to a much improved format
+        which includes recognition of ranges. It now supports the ranges that
+        are defined in UnicodeData.txt, and it also amalgamates other
+        characters into ranges. This has reduced the number of entries in the
+        table from around 16,000 to around 3,000, thus reducing its size
+        considerably. I realized I did not need to use a tree structure after
+        all - a binary chop search is just as efficient. Having reduced the
+        number of entries, I extended their size from 6 bytes to 8 bytes to
+        allow for more data.
+
+    (d) Added support for Unicode script names via properties such as \p{Han}.
+
+19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
+    matching that character.
+
+20. When matching a repeated Unicode property with a minimum greater than zero,
+    (for example \pL{2,}), PCRE could look past the end of the subject if it
+    reached it while seeking the minimum number of characters. This could
+    happen only if some of the characters were more than one byte long, because
+    there is a check for at least the minimum number of bytes.
+
+21. Refactored the implementation of \p and \P so as to be more general, to
+    allow for more different types of property in future. This has changed the
+    compiled form incompatibly. Anybody with saved compiled patterns that use
+    \p or \P will have to recompile them.
+
+22. Added "Any" and "L&" to the supported property types.
+
+23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
+    but give a compile time error if the value is greater than 0xff.
+
+24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
+    accidentally not being installed or uninstalled.
+
+25. The pcre.h file was built from pcre.h.in, but the only changes that were
+    made were to insert the current release number. This seemed silly, because
+    it made things harder for people building PCRE on systems that don't run
+    "configure". I have turned pcre.h into a distributed file, no longer built
+    by "configure", with the version identification directly included. There is
+    no longer a pcre.h.in file.
+
+    However, this change necessitated a change to the pcre-config script as
+    well. It is built from pcre-config.in, and one of the substitutions was the
+    release number. I have updated configure.ac so that ./configure now finds
+    the release number by grepping pcre.h.
+
+26. Added the ability to run the tests under valgrind.
+
+
+Version 6.4 05-Sep-05
+---------------------
+
+ 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
+    "--" to be printed when multiple files were scanned, even when none of the
+    -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
+    consider it to be a bug, and have restored the previous behaviour.
+
+ 2. A couple of code tidies to get rid of compiler warnings.
+
+ 3. The pcretest program used to cheat by referring to symbols in the library
+    whose names begin with _pcre_. These are internal symbols that are not
+    really supposed to be visible externally, and in some environments it is
+    possible to suppress them. The cheating is now confined to including
+    certain files from the library's source, which is a bit cleaner.
+
+ 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
+    file's purpose clearer.
+
+ 5. Reorganized pcre_ucp_findchar().
+
+
+Version 6.3 15-Aug-05
+---------------------
+
+ 1. The file libpcre.pc.in did not have general read permission in the tarball.
+
+ 2. There were some problems when building without C++ support:
+
+    (a) If C++ support was not built, "make install" and "make test" still
+        tried to test it.
+
+    (b) There were problems when the value of CXX was explicitly set. Some
+        changes have been made to try to fix these, and ...
+
+    (c) --disable-cpp can now be used to explicitly disable C++ support.
+
+    (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
+        backslash in a target when C++ was disabled. This confuses some
+        versions of "make", apparently. Using an intermediate variable solves
+        this. (Same for CPP_LOBJ.)
+
+ 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
+    (non-Windows) now includes $(CFLAGS) because these flags are sometimes
+    necessary on certain architectures.
+
+ 4. Added a setting of -export-symbols-regex to the link command to remove
+    those symbols that are exported in the C sense, but actually are local
+    within the library, and not documented. Their names all begin with
+    "_pcre_". This is not a perfect job, because (a) we have to except some
+    symbols that pcretest ("illegally") uses, and (b) the facility isn't always
+    available (and never for static libraries). I have made a note to try to
+    find a way round (a) in the future.
+
+
+Version 6.2 01-Aug-05
+---------------------
+
+ 1. There was no test for integer overflow of quantifier values. A construction
+    such as {1111111111111111} would give undefined results. What is worse, if
+    a minimum quantifier for a parenthesized subpattern overflowed and became
+    negative, the calculation of the memory size went wrong. This could have
+    led to memory overwriting.
+
+ 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
+
+ 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
+    operating environments where this matters.
+
+ 4. Applied Giuseppe Maxia's patch to add additional features for controlling
+    PCRE options from within the C++ wrapper.
+
+ 5. Named capturing subpatterns were not being correctly counted when a pattern
+    was compiled. This caused two problems: (a) If there were more than 100
+    such subpatterns, the calculation of the memory needed for the whole
+    compiled pattern went wrong, leading to an overflow error. (b) Numerical
+    back references of the form \12, where the number was greater than 9, were
+    not recognized as back references, even though there were sufficient
+    previous subpatterns.
+
+ 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
+    versions of gcc, e.g. 2.95.4.
+
+
+Version 6.1 21-Jun-05
+---------------------
+
+ 1. There was one reference to the variable "posix" in pcretest.c that was not
+    surrounded by "#if !defined NOPOSIX".
+
+ 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
+    the cross-check on the old pcre_info() function, for the benefit of the
+    cut-down version of PCRE that is currently imported into Exim.
+
+ 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
+    allocation error. I've done the easy fix, which wastes 2 bytes for sensible
+    patterns that start (?i) but I don't think that matters. The use of (?i) is
+    just an example; this all applies to the other options as well.
+
+ 4. Since libtool seems to echo the compile commands it is issuing, the output
+    from "make" can be reduced a bit by putting "@" in front of each libtool
+    compile command.
+
+ 5. Patch from the folks at Google for configure.in to be a bit more thorough
+    in checking for a suitable C++ installation before trying to compile the
+    C++ stuff. This should fix a reported problem when a compiler was present,
+    but no suitable headers.
+
+ 6. The man pages all had just "PCRE" as their title. I have changed them to
+    be the relevant file name. I have also arranged that these names are
+    retained in the file doc/pcre.txt, which is a concatenation in text format
+    of all the man pages except the little individual ones for each function.
+
+ 7. The NON-UNIX-USE file had not been updated for the different set of source
+    files that come with release 6. I also added a few comments about the C++
+    wrapper.
+
+
+Version 6.0 07-Jun-05
+---------------------
+
+ 1. Some minor internal re-organization to help with my DFA experiments.
+
+ 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
+    didn't matter for the library itself when fully configured, but did matter
+    when compiling without UCP support, or within Exim, where the ucp files are
+    not imported.
+
+ 3. Refactoring of the library code to split up the various functions into
+    different source modules. The addition of the new DFA matching code (see
+    below) to a single monolithic source would have made it really too
+    unwieldy, quite apart from causing all the code to be include in a
+    statically linked application, when only some functions are used. This is
+    relevant even without the DFA addition now that patterns can be compiled in
+    one application and matched in another.
+
+    The downside of splitting up is that there have to be some external
+    functions and data tables that are used internally in different modules of
+    the library but which are not part of the API. These have all had their
+    names changed to start with "_pcre_" so that they are unlikely to clash
+    with other external names.
+
+ 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
+    a different (DFA) algorithm. Although it is slower than the original
+    function, it does have some advantages for certain types of matching
+    problem.
+
+ 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
+    including restarting after a partial match.
+
+ 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
+    defined when compiling for Windows was sent to me. I have put it into the
+    code, though I have no means of testing or verifying it.
+
+ 7. Added the pcre_refcount() auxiliary function.
+
+ 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
+    match before or at the first newline in the subject string. In pcretest,
+    the /f option on a pattern can be used to set this.
+
+ 9. A repeated \w when used in UTF-8 mode with characters greater than 256
+    would behave wrongly. This has been present in PCRE since release 4.0.
+
+10. A number of changes to the pcregrep command:
+
+    (a) Refactored how -x works; insert ^(...)$ instead of setting
+        PCRE_ANCHORED and checking the length, in preparation for adding
+        something similar for -w.
+
+    (b) Added the -w (match as a word) option.
+
+    (c) Refactored the way lines are read and buffered so as to have more
+        than one at a time available.
+
+    (d) Implemented a pcregrep test script.
+
+    (e) Added the -M (multiline match) option. This allows patterns to match
+        over several lines of the subject. The buffering ensures that at least
+        8K, or the rest of the document (whichever is the shorter) is available
+        for matching (and similarly the previous 8K for lookbehind assertions).
+
+    (f) Changed the --help output so that it now says
+
+          -w, --word-regex(p)
+
+        instead of two lines, one with "regex" and the other with "regexp"
+        because that confused at least one person since the short forms are the
+        same. (This required a bit of code, as the output is generated
+        automatically from a table. It wasn't just a text change.)
+
+    (g) -- can be used to terminate pcregrep options if the next thing isn't an
+        option but starts with a hyphen. Could be a pattern or a path name
+        starting with a hyphen, for instance.
+
+    (h) "-" can be given as a file name to represent stdin.
+
+    (i) When file names are being printed, "(standard input)" is used for
+        the standard input, for compatibility with GNU grep. Previously
+        "<stdin>" was used.
+
+    (j) The option --label=xxx can be used to supply a name to be used for
+        stdin when file names are being printed. There is no short form.
+
+    (k) Re-factored the options decoding logic because we are going to add
+        two more options that take data. Such options can now be given in four
+        different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
+
+    (l) Added the -A, -B, and -C options for requesting that lines of context
+        around matches be printed.
+
+    (m) Added the -L option to print the names of files that do not contain
+        any matching lines, that is, the complement of -l.
+
+    (n) The return code is 2 if any file cannot be opened, but pcregrep does
+        continue to scan other files.
+
+    (o) The -s option was incorrectly implemented. For compatibility with other
+        greps, it now suppresses the error message for a non-existent or non-
+        accessible file (but not the return code). There is a new option called
+        -q that suppresses the output of matching lines, which was what -s was
+        previously doing.
+
+    (p) Added --include and --exclude options to specify files for inclusion
+        and exclusion when recursing.
+
+11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
+    Hopefully, it now does.
+
+12. Missing cast in pcre_study().
+
+13. Added an "uninstall" target to the makefile.
+
+14. Replaced "extern" in the function prototypes in Makefile.in with
+    "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
+    world, but is set differently for Windows.
+
+15. Added a second compiling function called pcre_compile2(). The only
+    difference is that it has an extra argument, which is a pointer to an
+    integer error code. When there is a compile-time failure, this is set
+    non-zero, in addition to the error test pointer being set to point to an
+    error message. The new argument may be NULL if no error number is required
+    (but then you may as well call pcre_compile(), which is now just a
+    wrapper). This facility is provided because some applications need a
+    numeric error indication, but it has also enabled me to tidy up the way
+    compile-time errors are handled in the POSIX wrapper.
+
+16. Added VPATH=.libs to the makefile; this should help when building with one
+    prefix path and installing with another. (Or so I'm told by someone who
+    knows more about this stuff than I do.)
+
+17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
+    passes PCRE_DOTALL to the pcre_compile() function, making the "." character
+    match everything, including newlines. This is not POSIX-compatible, but
+    somebody wanted the feature. From pcretest it can be activated by using
+    both the P and the s flags.
+
+18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
+
+19. libpcre.pc was being incorrectly installed as executable.
+
+20. A couple of places in pcretest check for end-of-line by looking for '\n';
+    it now also looks for '\r' so that it will work unmodified on Windows.
+
+21. Added Google's contributed C++ wrapper to the distribution.
+
+22. Added some untidy missing memory free() calls in pcretest, to keep
+    Electric Fence happy when testing.
+
+
+
+Version 5.0 13-Sep-04
+---------------------
+
+ 1. Internal change: literal characters are no longer packed up into items
+    containing multiple characters in a single byte-string. Each character
+    is now matched using a separate opcode. However, there may be more than one
+    byte in the character in UTF-8 mode.
+
+ 2. The pcre_callout_block structure has two new fields: pattern_position and
+    next_item_length. These contain the offset in the pattern to the next match
+    item, and its length, respectively.
+
+ 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
+    insertion of callouts before each pattern item. Added the /C option to
+    pcretest to make use of this.
+
+ 4. On the advice of a Windows user, the lines
+
+      #if defined(_WIN32) || defined(WIN32)
+      _setmode( _fileno( stdout ), 0x8000 );
+      #endif  /* defined(_WIN32) || defined(WIN32) */
+
+    have been added to the source of pcretest. This apparently does useful
+    magic in relation to line terminators.
+
+ 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
+    for the benefit of those environments where the "b" makes a difference.
+
+ 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
+    to know about it. I have put a hack into configure.in that adds in code
+    to set GCC=yes if CC=icc. This seems to end up at a point in the
+    generated configure script that is early enough to affect the setting of
+    compiler options, which is what is needed, but I have no means of testing
+    whether it really works. (The user who reported this had patched the
+    generated configure script, which of course I cannot do.)
+
+    LATER: After change 22 below (new libtool files), the configure script
+    seems to know about icc (and also ecc). Therefore, I have commented out
+    this hack in configure.in.
+
+ 7. Added support for pkg-config (2 patches were sent in).
+
+ 8. Negated POSIX character classes that used a combination of internal tables
+    were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
+    [[:^ascii]]. Typically, they would match almost any characters. The other
+    POSIX classes were not broken in this way.
+
+ 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
+    to find the match, as PCRE was deluded into thinking that the match had to
+    start at the start point or following a newline. The same bug applied to
+    patterns with negative forward assertions or any backward assertions
+    preceding ".*" at the start, unless the pattern required a fixed first
+    character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
+
+10. In UTF-8 mode, when moving forwards in the subject after a failed match
+    starting at the last subject character, bytes beyond the end of the subject
+    string were read.
+
+11. Renamed the variable "class" as "classbits" to make life easier for C++
+    users. (Previously there was a macro definition, but it apparently wasn't
+    enough.)
+
+12. Added the new field "tables" to the extra data so that tables can be passed
+    in at exec time, or the internal tables can be re-selected. This allows
+    a compiled regex to be saved and re-used at a later time by a different
+    program that might have everything at different addresses.
+
+13. Modified the pcre-config script so that, when run on Solaris, it shows a
+    -R library as well as a -L library.
+
+14. The debugging options of pcretest (-d on the command line or D on a
+    pattern) showed incorrect output for anything following an extended class
+    that contained multibyte characters and which was followed by a quantifier.
+
+15. Added optional support for general category Unicode character properties
+    via the \p, \P, and \X escapes. Unicode property support implies UTF-8
+    support. It adds about 90K to the size of the library. The meanings of the
+    inbuilt class escapes such as \d and \s have NOT been changed.
+
+16. Updated pcredemo.c to include calls to free() to release the memory for the
+    compiled pattern.
+
+17. The generated file chartables.c was being created in the source directory
+    instead of in the building directory. This caused the build to fail if the
+    source directory was different from the building directory, and was
+    read-only.
+
+18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
+    file. No doubt somebody will tell me if they don't make sense... Also added
+    Dan Mooney's comments about building on OpenVMS.
+
+19. Added support for partial matching via the PCRE_PARTIAL option for
+    pcre_exec() and the \P data escape in pcretest.
+
+20. Extended pcretest with 3 new pattern features:
+
+    (i)   A pattern option of the form ">rest-of-line" causes pcretest to
+          write the compiled pattern to the file whose name is "rest-of-line".
+          This is a straight binary dump of the data, with the saved pointer to
+          the character tables forced to be NULL. The study data, if any, is
+          written too. After writing, pcretest reads a new pattern.
+
+    (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
+          compiled pattern from the given file. There must not be any
+          occurrences of "<" in the file name (pretty unlikely); if there are,
+          pcretest will instead treat the initial "<" as a pattern delimiter.
+          After reading in the pattern, pcretest goes on to read data lines as
+          usual.
+
+    (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
+          and 16-bit fields in a compiled pattern, to simulate a pattern that
+          was compiled on a host of opposite endianness.
+
+21. The pcre-exec() function can now cope with patterns that were compiled on
+    hosts of opposite endianness, with this restriction:
+
+      As for any compiled expression that is saved and used later, the tables
+      pointer field cannot be preserved; the extra_data field in the arguments
+      to pcre_exec() should be used to pass in a tables address if a value
+      other than the default internal tables were used at compile time.
+
+22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
+    now diagnosed as an error. Previously, most of the time, a negative number
+    would have been treated as zero, but if in addition "ovector" was passed as
+    NULL, a crash could occur.
+
+23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
+    new versions from the libtool 1.5 distribution (the last one is a copy of
+    a file called libtool.m4). This seems to have fixed the need to patch
+    "configure" to support Darwin 1.3 (which I used to do). However, I still
+    had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
+    workstation).
+
+24. Changed the PCRE licence to be the more standard "BSD" licence.
+
+
+Version 4.5 01-Dec-03
+---------------------
+
+ 1. There has been some re-arrangement of the code for the match() function so
+    that it can be compiled in a version that does not call itself recursively.
+    Instead, it keeps those local variables that need separate instances for
+    each "recursion" in a frame on the heap, and gets/frees frames whenever it
+    needs to "recurse". Keeping track of where control must go is done by means
+    of setjmp/longjmp. The whole thing is implemented by a set of macros that
+    hide most of the details from the main code, and operates only if
+    NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
+    "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
+    operating.
+
+    To make it easier for callers to provide specially tailored get/free
+    functions for this usage, two new functions, pcre_stack_malloc, and
+    pcre_stack_free, are used. They are always called in strict stacking order,
+    and the size of block requested is always the same.
+
+    The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
+    PCRE has been compiled to use the stack or the heap for recursion. The
+    -C option of pcretest uses this to show which version is compiled.
+
+    A new data escape \S, is added to pcretest; it causes the amounts of store
+    obtained and freed by both kinds of malloc/free at match time to be added
+    to the output.
+
+ 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
+    what's available on my current Linux desktop machine.
+
+ 3. When matching a UTF-8 string, the test for a valid string at the start has
+    been extended. If start_offset is not zero, PCRE now checks that it points
+    to a byte that is the start of a UTF-8 character. If not, it returns
+    PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
+    this is necessary because there may be backward assertions in the pattern.
+    When matching the same subject several times, it may save resources to use
+    PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
+
+ 4. The code for checking the validity of UTF-8 strings has been tightened so
+    that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
+    containing "overlong sequences".
+
+ 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
+    I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
+    should have been "&", but it just so happened that all the cases this let
+    through by mistake were picked up later in the function.
+
+ 6. I had used a variable called "isblank" - this is a C99 function, causing
+    some compilers to warn. To avoid this, I renamed it (as "blankclass").
+
+ 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
+    prompting; (b) run "./pcretest /dev/null" at the start of the test script
+    so the version is shown; (c) stop "make test" echoing "./RunTest".
+
+ 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
+
+ 9. The prototype for memmove() for systems that don't have it was using
+    size_t, but the inclusion of the header that defines size_t was later. I've
+    moved the #includes for the C headers earlier to avoid this.
+
+10. Added some adjustments to the code to make it easier to compiler on certain
+    special systems:
+
+      (a) Some "const" qualifiers were missing.
+      (b) Added the macro EXPORT before all exported functions; by default this
+          is defined to be empty.
+      (c) Changed the dftables auxiliary program (that builds chartables.c) so
+          that it reads its output file name as an argument instead of writing
+          to the standard output and assuming this can be redirected.
+
+11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
+    class containing characters with values greater than 255, PCRE compilation
+    went into a loop.
+
+12. A recursive reference to a subpattern that was within another subpattern
+    that had a minimum quantifier of zero caused PCRE to crash. For example,
+    (x(y(?2))z)? provoked this bug with a subject that got as far as the
+    recursion. If the recursively-called subpattern itself had a zero repeat,
+    that was OK.
+
+13. In pcretest, the buffer for reading a data line was set at 30K, but the
+    buffer into which it was copied (for escape processing) was still set at
+    1024, so long lines caused crashes.
+
+14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
+    "internal error: code overflow...". This applied to any character class
+    that was followed by a possessive quantifier.
+
+15. Modified the Makefile to add libpcre.la as a prerequisite for
+    libpcreposix.la because I was told this is needed for a parallel build to
+    work.
+
+16. If a pattern that contained .* following optional items at the start was
+    studied, the wrong optimizing data was generated, leading to matching
+    errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
+    matching string must start with a or b or c. The correct conclusion for
+    this pattern is that a match can start with any character.
+
+
+Version 4.4 13-Aug-03
+---------------------
+
+ 1. In UTF-8 mode, a character class containing characters with values between
+    127 and 255 was not handled correctly if the compiled pattern was studied.
+    In fixing this, I have also improved the studying algorithm for such
+    classes (slightly).
+
+ 2. Three internal functions had redundant arguments passed to them. Removal
+    might give a very teeny performance improvement.
+
+ 3. Documentation bug: the value of the capture_top field in a callout is *one
+    more than* the number of the hightest numbered captured substring.
+
+ 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
+    in incorrectly linking with a previously installed version. They now link
+    explicitly with libpcre.la.
+
+ 5. configure.in no longer needs to recognize Cygwin specially.
+
+ 6. A problem in pcre.in for Windows platforms is fixed.
+
+ 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
+    pcretest, it used to include the size of the study block as part of its
+    output. Unfortunately, the structure contains a field that has a different
+    size on different hardware architectures. This meant that the tests that
+    showed this size failed. As the block is currently always of a fixed size,
+    this information isn't actually particularly useful in pcretest output, so
+    I have just removed it.
+
+ 8. Three pre-processor statements accidentally did not start in column 1.
+    Sadly, there are *still* compilers around that complain, even though
+    standard C has not required this for well over a decade. Sigh.
+
+ 9. In pcretest, the code for checking callouts passed small integers in the
+    callout_data field, which is a void * field. However, some picky compilers
+    complained about the casts involved for this on 64-bit systems. Now
+    pcretest passes the address of the small integer instead, which should get
+    rid of the warnings.
+
+10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
+    both compile and run time, and gives an error if an invalid UTF-8 sequence
+    is found. There is a option for disabling this check in cases where the
+    string is known to be correct and/or the maximum performance is wanted.
+
+11. In response to a bug report, I changed one line in Makefile.in from
+
+        -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
+    to
+        -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
+
+    to look similar to other lines, but I have no way of telling whether this
+    is the right thing to do, as I do not use Windows. No doubt I'll get told
+    if it's wrong...
+
+
+Version 4.3 21-May-03
+---------------------
+
+1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
+   Makefile.
+
+2. Some refactoring to improve the quality of the code:
+
+   (i)   The utf8_table... variables are now declared "const".
+
+   (ii)  The code for \cx, which used the "case flipping" table to upper case
+         lower case letters, now just substracts 32. This is ASCII-specific,
+         but the whole concept of \cx is ASCII-specific, so it seems
+         reasonable.
+
+   (iii) PCRE was using its character types table to recognize decimal and
+         hexadecimal digits in the pattern. This is silly, because it handles
+         only 0-9, a-f, and A-F, but the character types table is locale-
+         specific, which means strange things might happen. A private
+         table is now used for this - though it costs 256 bytes, a table is
+         much faster than multiple explicit tests. Of course, the standard
+         character types table is still used for matching digits in subject
+         strings against \d.
+
+   (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
+         ending in _t are). So I've renamed it as ESC_tee.
+
+3. The first argument for regexec() in the POSIX wrapper should have been
+   defined as "const".
+
+4. Changed pcretest to use malloc() for its buffers so that they can be
+   Electric Fenced for debugging.
+
+5. There were several places in the code where, in UTF-8 mode, PCRE would try
+   to read one or more bytes before the start of the subject string. Often this
+   had no effect on PCRE's behaviour, but in some circumstances it could
+   provoke a segmentation fault.
+
+6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
+   to try to read one or more bytes before the start of the subject string.
+
+7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
+   UTF-8 support could misbehave in various ways if the subject string
+   contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
+   area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
+   back over UTF-8 characters.)
+
+
+Version 4.2 14-Apr-03
+---------------------
+
+1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
+
+2. Changes to the building process, supplied by Ronald Landheer-Cieslak
+     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
+     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
+     [WIN_PREFIX]: new variable, "cyg" for Cygwin
+     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
+       and BUILD_EXEEXT
+     Note: automatic setting of the BUILD variables is not yet working
+     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
+       compile-time but not at link-time
+     [LINK]: use for linking executables only
+     make different versions for Windows and non-Windows
+     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
+       libraries
+     [LINK_FOR_BUILD]: new variable
+     [OBJEXT]: use throughout
+     [EXEEXT]: use throughout
+     <winshared>: new target
+     <wininstall>: new target
+     <dftables.o>: use native compiler
+     <dftables>: use native linker
+     <install>: handle Windows platform correctly
+     <clean>: ditto
+     <check>: ditto
+     copy DLL to top builddir before testing
+
+   As part of these changes, -no-undefined was removed again. This was reported
+   to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
+   in any case.
+
+3. Some tidies to get rid of compiler warnings:
+
+   . In the match_data structure, match_limit was an unsigned long int, whereas
+     match_call_count was an int. I've made them both unsigned long ints.
+
+   . In pcretest the fact that a const uschar * doesn't automatically cast to
+     a void * provoked a warning.
+
+   . Turning on some more compiler warnings threw up some "shadow" variables
+     and a few more missing casts.
+
+4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
+   option, a class that contained a single character with a value between 128
+   and 255 (e.g. /[\xFF]/) caused PCRE to crash.
+
+5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
+   option, a class that contained several characters, but with at least one
+   whose value was between 128 and 255 caused PCRE to crash.
+
+
+Version 4.1 12-Mar-03
+---------------------
+
+1. Compiling with gcc -pedantic found a couple of places where casts were
+needed, and a string in dftables.c that was longer than standard compilers are
+required to support.
+
+2. Compiling with Sun's compiler found a few more places where the code could
+be tidied up in order to avoid warnings.
+
+3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
+first of these names is deprecated in the latest Autoconf in favour of the name
+CC_FOR_BUILD, because "host" is typically used to mean the system on which the
+compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
+analogy I have changed it to CFLAGS_FOR_BUILD.
+
+4. Added -no-undefined to the linking command in the Makefile, because this is
+apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
+linking step for the pcreposix library.
+
+5. PCRE was failing to diagnose the case of two named groups with the same
+name.
+
+6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
+literal character that is needed in the subject for a match, and scans along to
+ensure that it is present before embarking on the full matching process. This
+saves time in cases of nested unlimited repeats that are never going to match.
+Problem: the scan can take a lot of time if the subject is very long (e.g.
+megabytes), thus penalizing straightforward matches. It is now done only if the
+amount of subject to be scanned is less than 1000 bytes.
+
+7. A lesser problem with the same optimization is that it was recording the
+first character of an anchored pattern as "needed", thus provoking a search
+right along the subject, even when the first match of the pattern was going to
+fail. The "needed" character is now not set for anchored patterns, unless it
+follows something in the pattern that is of non-fixed length. Thus, it still
+fulfils its original purpose of finding quick non-matches in cases of nested
+unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
+
+
+Version 4.0 17-Feb-03
+---------------------
+
+1. If a comment in an extended regex that started immediately after a meta-item
+extended to the end of string, PCRE compiled incorrect data. This could lead to
+all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
+
+2. Moved to autoconf 2.53 and libtool 1.4.2.
+
+3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
+the special perltest8 script is no longer needed - all the tests can be run
+from a single perltest script.
+
+4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
+by \s. It has now been removed in PCRE. This means it isn't recognized as
+whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
+class [:space:] *does* include VT, thereby creating a mess.
+
+5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
+space and tab.
+
+6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
+its new features into the main test script, reducing the number of scripts.
+
+7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
+were backward compatible, and made the (?i) apply to the whole pattern, as if
+/i were given. Now it behaves more logically, and applies the option setting
+only to what follows. PCRE has been changed to follow suit. However, if it
+finds options settings right at the start of the pattern, it extracts them into
+the global options, as before. Thus, they show up in the info data.
+
+8. Added support for the \Q...\E escape sequence. Characters in between are
+treated as literals. This is slightly different from Perl in that $ and @ are
+also handled as literals inside the quotes. In Perl, they will cause variable
+interpolation. Note the following examples:
+
+    Pattern            PCRE matches      Perl matches
+
+    \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
+    \Qabc\$xyz\E       abc\$xyz          abc\$xyz
+    \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
+
+For compatibility with Perl, \Q...\E sequences are recognized inside character
+classes as well as outside them.
+
+9. Re-organized 3 code statements in pcretest to avoid "overflow in
+floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
+(size_t) cast to one statement in pcretest and one in pcreposix to avoid
+signed/unsigned warnings.
+
+10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
+option for pcretest, so I've replaced it by a simple function that does just
+that job.
+
+11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
+"pcregrep -".
+
+12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
+Java package. This provides some syntactic sugar for simple cases of what my
+documentation calls "once-only subpatterns". A pattern such as x*+ is the same
+as (?>x*). In other words, if what is inside (?>...) is just a single repeated
+item, you can use this simplified notation. Note that only makes sense with
+greedy quantifiers. Consequently, the use of the possessive quantifier forces
+greediness, whatever the setting of the PCRE_UNGREEDY option.
+
+13. A change of greediness default within a pattern was not taking effect at
+the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
+subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
+was abstracted outside.
+
+14. PCRE now supports the \G assertion. It is true when the current matching
+position is at the start point of the match. This differs from \A when the
+starting offset is non-zero. Used with the /g option of pcretest (or similar
+code), it works in the same way as it does for Perl's /g option. If all
+alternatives of a regex begin with \G, the expression is anchored to the start
+match position, and the "anchored" flag is set in the compiled expression.
+
+15. Some bugs concerning the handling of certain option changes within patterns
+have been fixed. These applied to options other than (?ims). For example,
+"a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
+been the other way round. Some of this was related to change 7 above.
+
+16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
+features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
+and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
+POSIX classes only within a class (e.g. /[[:alpha:]]/).
+
+17. Added support for Perl's \C escape. This matches one byte, even in UTF8
+mode. Unlike ".", it always matches newline, whatever the setting of
+PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
+assertions. Perl allows it, but it doesn't (in general) work because it can't
+calculate the length of the lookbehind. At least, that's the case for Perl
+5.8.0 - I've been told they are going to document that it doesn't work in
+future.
+
+18. Added an error diagnosis for escapes that PCRE does not support: these are
+\L, \l, \N, \P, \p, \U, \u, and \X.
+
+19. Although correctly diagnosing a missing ']' in a character class, PCRE was
+reading past the end of the pattern in cases such as /[abcd/.
+
+20. PCRE was getting more memory than necessary for patterns with classes that
+contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
+
+21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
+compiling PCRE for use with Virtual Pascal.
+
+22. Small fix to the Makefile to make it work properly if the build is done
+outside the source tree.
+
+23. Added a new extension: a condition to go with recursion. If a conditional
+subpattern starts with (?(R) the "true" branch is used if recursion has
+happened, whereas the "false" branch is used only at the top level.
+
+24. When there was a very long string of literal characters (over 255 bytes
+without UTF support, over 250 bytes with UTF support), the computation of how
+much memory was required could be incorrect, leading to segfaults or other
+strange effects.
+
+25. PCRE was incorrectly assuming anchoring (either to start of subject or to
+start of line for a non-DOTALL pattern) when a pattern started with (.*) and
+there was a subsequent back reference to those brackets. This meant that, for
+example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
+possible to check for precisely this case. All we can do is abandon the
+optimization if .* occurs inside capturing brackets when there are any back
+references whatsoever. (See below for a better fix that came later.)
+
+26. The handling of the optimization for finding the first character of a
+non-anchored pattern, and for finding a character that is required later in the
+match were failing in some cases. This didn't break the matching; it just
+failed to optimize when it could. The way this is done has been re-implemented.
+
+27. Fixed typo in error message for invalid (?R item (it said "(?p").
+
+28. Added a new feature that provides some of the functionality that Perl
+provides with (?{...}). The facility is termed a "callout". The way it is done
+in PCRE is for the caller to provide an optional function, by setting
+pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
+global variable. By default it is unset, which disables all calling out. To get
+the function called, the regex must include (?C) at appropriate points. This
+is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
+This provides a means of identifying different callout points. When PCRE
+reaches such a point in the regex, if pcre_callout has been set, the external
+function is called. It is provided with data in a structure called
+pcre_callout_block, which is defined in pcre.h. If the function returns 0,
+matching continues; if it returns a non-zero value, the match at the current
+point fails. However, backtracking will occur if possible. [This was changed
+later and other features added - see item 49 below.]
+
+29. pcretest is upgraded to test the callout functionality. It provides a
+callout function that displays information. By default, it shows the start of
+the match and the current position in the text. There are some new data escapes
+to vary what happens:
+
+    \C+         in addition, show current contents of captured substrings
+    \C-         do not supply a callout function
+    \C!n        return 1 when callout number n is reached
+    \C!n!m      return 1 when callout number n is reached for the mth time
+
+30. If pcregrep was called with the -l option and just a single file name, it
+output "<stdin>" if a match was found, instead of the file name.
+
+31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
+slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
+pcre_exec(). This saves a malloc/free per call. The default value of
+POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
+when configuring.
+
+32. The default maximum size of a compiled pattern is 64K. There have been a
+few cases of people hitting this limit. The code now uses macros to handle the
+storing of links as offsets within the compiled pattern. It defaults to 2-byte
+links, but this can be changed to 3 or 4 bytes by --with-link-size when
+configuring. Tests 2 and 5 work only with 2-byte links because they output
+debugging information about compiled patterns.
+
+33. Internal code re-arrangements:
+
+(a) Moved the debugging function for printing out a compiled regex into
+    its own source file (printint.c) and used #include to pull it into
+    pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
+    separate copies.
+
+(b) Defined the list of op-code names for debugging as a macro in
+    internal.h so that it is next to the definition of the opcodes.
+
+(c) Defined a table of op-code lengths for simpler skipping along compiled
+    code. This is again a macro in internal.h so that it is next to the
+    definition of the opcodes.
+
+34. Added support for recursive calls to individual subpatterns, along the
+lines of Robin Houston's patch (but implemented somewhat differently).
+
+35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
+allow it to read and process whole directories in Win32. This code was
+contributed by Lionel Fourquaux; it has not been tested by me.
+
+36. Added support for named subpatterns. The Python syntax (?P<name>...) is
+used to name a group. Names consist of alphanumerics and underscores, and must
+be unique. Back references use the syntax (?P=name) and recursive calls use
+(?P>name) which is a PCRE extension to the Python extension. Groups still have
+numbers. The function pcre_fullinfo() can be used after compilation to extract
+a name/number map. There are three relevant calls:
+
+  PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
+  PCRE_INFO_NAMECOUNT            yields the number of entries
+  PCRE_INFO_NAMETABLE            yields a pointer to the map.
+
+The map is a vector of fixed-size entries. The size of each entry depends on
+the length of the longest name used. The first two bytes of each entry are the
+group number, most significant byte first. There follows the corresponding
+name, zero terminated. The names are in alphabetical order.
+
+37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
+case instead of 255. Making it the same both with and without UTF-8 support
+means that the same test output works with both.
+
+38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
+calling malloc() with a zero argument.
+
+39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
+optimization. I've improved things by keeping a bitmap of backreferences with
+numbers 1-31 so that if .* occurs inside capturing brackets that are not in
+fact referenced, the optimization can be applied. It is unlikely that a
+relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
+the match to follow \n) will appear inside brackets with a number greater than
+31, but if it does, any back reference > 31 suppresses the optimization.
+
+40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
+of disabling numbered capturing parentheses. Any opening parenthesis that is
+not followed by ? behaves as if it were followed by ?: but named parentheses
+can still be used for capturing (and they will acquire numbers in the usual
+way).
+
+41. Redesigned the return codes from the match() function into yes/no/error so
+that errors can be passed back from deep inside the nested calls. A malloc
+failure while inside a recursive subpattern call now causes the
+PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
+
+42. It is now possible to set a limit on the number of times the match()
+function is called in a call to pcre_exec(). This facility makes it possible to
+limit the amount of recursion and backtracking, though not in a directly
+obvious way, because the match() function is used in a number of different
+circumstances. The count starts from zero for each position in the subject
+string (for non-anchored patterns). The default limit is, for compatibility, a
+large number, namely 10 000 000. You can change this in two ways:
+
+(a) When configuring PCRE before making, you can use --with-match-limit=n
+    to set a default value for the compiled library.
+
+(b) For each call to pcre_exec(), you can pass a pcre_extra block in which
+    a different value is set. See 45 below.
+
+If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
+
+43. Added a new function pcre_config(int, void *) to enable run-time extraction
+of things that can be changed at compile time. The first argument specifies
+what is wanted and the second points to where the information is to be placed.
+The current list of available information is:
+
+  PCRE_CONFIG_UTF8
+
+The output is an integer that is set to one if UTF-8 support is available;
+otherwise it is set to zero.
+
+  PCRE_CONFIG_NEWLINE
+
+The output is an integer that it set to the value of the code that is used for
+newline. It is either LF (10) or CR (13).
+
+  PCRE_CONFIG_LINK_SIZE
+
+The output is an integer that contains the number of bytes used for internal
+linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
+
+  PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
+
+The output is an integer that contains the threshold above which the POSIX
+interface uses malloc() for output vectors. See item 31 above.
+
+  PCRE_CONFIG_MATCH_LIMIT
+
+The output is an unsigned integer that contains the default limit of the number
+of match() calls in a pcre_exec() execution. See 42 above.
+
+44. pcretest has been upgraded by the addition of the -C option. This causes it
+to extract all the available output from the new pcre_config() function, and to
+output it. The program then exits immediately.
+
+45. A need has arisen to pass over additional data with calls to pcre_exec() in
+order to support additional features. One way would have been to define
+pcre_exec2() (for example) with extra arguments, but this would not have been
+extensible, and would also have required all calls to the original function to
+be mapped to the new one. Instead, I have chosen to extend the mechanism that
+is used for passing in "extra" data from pcre_study().
+
+The pcre_extra structure is now exposed and defined in pcre.h. It currently
+contains the following fields:
+
+  flags         a bitmap indicating which of the following fields are set
+  study_data    opaque data from pcre_study()
+  match_limit   a way of specifying a limit on match() calls for a specific
+                  call to pcre_exec()
+  callout_data  data for callouts (see 49 below)
+
+The flag bits are also defined in pcre.h, and are
+
+  PCRE_EXTRA_STUDY_DATA
+  PCRE_EXTRA_MATCH_LIMIT
+  PCRE_EXTRA_CALLOUT_DATA
+
+The pcre_study() function now returns one of these new pcre_extra blocks, with
+the actual study data pointed to by the study_data field, and the
+PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
+before. That is, this change is entirely upwards-compatible and requires no
+change to existing code.
+
+If you want to pass in additional data to pcre_exec(), you can either place it
+in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
+block.
+
+46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
+data string contains the escape sequence \M, pcretest calls pcre_exec() several
+times with different match limits, until it finds the minimum value needed for
+pcre_exec() to complete. The value is then output. This can be instructive; for
+most simple matches the number is quite small, but for pathological cases it
+gets very large very quickly.
+
+47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
+returns the size of the data block pointed to by the study_data field in a
+pcre_extra block, that is, the value that was passed as the argument to
+pcre_malloc() when PCRE was getting memory in which to place the information
+created by pcre_study(). The fourth argument should point to a size_t variable.
+pcretest has been extended so that this information is shown after a successful
+pcre_study() call when information about the compiled regex is being displayed.
+
+48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
+because what follows is always an absolute path. (Later: it turns out that this
+is more than cosmetic for MinGW, because it doesn't like empty path
+components.)
+
+49. Some changes have been made to the callout feature (see 28 above):
+
+(i)  A callout function now has three choices for what it returns:
+
+       0  =>  success, carry on matching
+     > 0  =>  failure at this point, but backtrack if possible
+     < 0  =>  serious error, return this value from pcre_exec()
+
+     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
+     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
+     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
+     use by callout functions. It will never be used by PCRE itself.
+
+(ii) The pcre_extra structure (see 45 above) has a void * field called
+     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
+     pcre_callout_block structure has a field of the same name. The contents of
+     the field passed in the pcre_extra structure are passed to the callout
+     function in the corresponding field in the callout block. This makes it
+     easier to use the same callout-containing regex from multiple threads. For
+     testing, the pcretest program has a new data escape
+
+       \C*n        pass the number n (may be negative) as callout_data
+
+     If the callout function in pcretest receives a non-zero value as
+     callout_data, it returns that value.
+
+50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
+there were some redundant $(CFLAGS) in commands that are now specified as
+$(LINK), which already includes $(CFLAGS).
+
+51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
+has been compiled with UTF-8 support *and* pcre_compile() has been compiled
+with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
+one-byte characters throughout. Note that case-insensitive matching applies
+only to characters whose values are less than 256. PCRE doesn't support the
+notion of cases for higher-valued characters.
+
+(i)   A character class whose characters are all within 0-255 is handled as
+      a bit map, and the map is inverted for negative classes. Previously, a
+      character > 255 always failed to match such a class; however it should
+      match if the class was a negative one (e.g. [^ab]). This has been fixed.
+
+(ii)  A negated character class with a single character < 255 is coded as
+      "not this character" (OP_NOT). This wasn't working properly when the test
+      character was multibyte, either singly or repeated.
+
+(iii) Repeats of multibyte characters are now handled correctly in UTF-8
+      mode, for example: \x{100}{2,3}.
+
+(iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
+      singly or repeated) now correctly test multibyte characters. However,
+      PCRE doesn't recognize any characters with values greater than 255 as
+      digits, spaces, or word characters. Such characters always match \D, \S,
+      and \W, and never match \d, \s, or \w.
+
+(v)   Classes may now contain characters and character ranges with values
+      greater than 255. For example: [ab\x{100}-\x{400}].
+
+(vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
+      PCRE in UTF-8 mode.
+
+52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
+PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
+retained for backwards compatibility. (Note that LASTLITERAL is also a byte
+value.)
+
+53. The single man page has become too large. I have therefore split it up into
+a number of separate man pages. These also give rise to individual HTML pages;
+these are now put in a separate directory, and there is an index.html page that
+lists them all. Some hyperlinking between the pages has been installed.
+
+54. Added convenience functions for handling named capturing parentheses.
+
+55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
+aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
+true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
+are faulted.
+
+56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
+calling configure. These values are used when compiling the dftables.c program
+which is run to generate the source of the default character tables. They
+default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
+you will need to set these values.
+
+57. Updated the building process for Windows DLL, as provided by Fred Cox.
+
+
+Version 3.9 02-Jan-02
+---------------------
+
+1. A bit of extraneous text had somehow crept into the pcregrep documentation.
+
+2. If --disable-static was given, the building process failed when trying to
+build pcretest and pcregrep. (For some reason it was using libtool to compile
+them, which is not right, as they aren't part of the library.)
+
+
+Version 3.8 18-Dec-01
+---------------------
+
+1. The experimental UTF-8 code was completely screwed up. It was packing the
+bytes in the wrong order. How dumb can you get?
+
+
+Version 3.7 29-Oct-01
+---------------------
+
+1. In updating pcretest to check change 1 of version 3.6, I screwed up.
+This caused pcretest, when used on the test data, to segfault. Unfortunately,
+this didn't happen under Solaris 8, where I normally test things.
+
+2. The Makefile had to be changed to make it work on BSD systems, where 'make'
+doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
+isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
+this fix an hour or so after the initial 3.7 release.)
+
+
+Version 3.6 23-Oct-01
+---------------------
+
+1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
+offsets passed as NULL with zero offset count.
+
+2. The config.guess and config.sub files had not been updated when I moved to
+the latest autoconf.
+
+
+Version 3.5 15-Aug-01
+---------------------
+
+1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
+had been forgotten.
+
+2. By using declared but undefined structures, we can avoid using "void"
+definitions in pcre.h while keeping the internal definitions of the structures
+private.
+
+3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
+user point of view, this means that both static and shared libraries are built
+by default, but this can be individually controlled. More of the work of
+handling this static/shared cases is now inside libtool instead of PCRE's make
+file.
+
+4. The pcretest utility is now installed along with pcregrep because it is
+useful for users (to test regexs) and by doing this, it automatically gets
+relinked by libtool. The documentation has been turned into a man page, so
+there are now .1, .txt, and .html versions in /doc.
+
+5. Upgrades to pcregrep:
+   (i)   Added long-form option names like gnu grep.
+   (ii)  Added --help to list all options with an explanatory phrase.
+   (iii) Added -r, --recursive to recurse into sub-directories.
+   (iv)  Added -f, --file to read patterns from a file.
+
+6. pcre_exec() was referring to its "code" argument before testing that
+argument for NULL (and giving an error if it was NULL).
+
+7. Upgraded Makefile.in to allow for compiling in a different directory from
+the source directory.
+
+8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
+options bits, the pointer it was passed was to an int instead of to an unsigned
+long int. This mattered only on 64-bit systems.
+
+9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
+generated) instead of pcre.in, which it its source. Also made the same change
+in several of the .c files.
+
+10. A new release of gcc defines printf() as a macro, which broke pcretest
+because it had an ifdef in the middle of a string argument for printf(). Fixed
+by using separate calls to printf().
+
+11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
+script, to force use of CR or LF instead of \n in the source. On non-Unix
+systems, the value can be set in config.h.
+
+12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
+absolute limit. Changed the text of the error message to make this clear, and
+likewise updated the man page.
+
+13. The limit of 99 on the number of capturing subpatterns has been removed.
+The new limit is 65535, which I hope will not be a "real" limit.
+
+
+Version 3.4 22-Aug-00
+---------------------
+
+1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
+
+2. Diagnose condition (?(0) as an error instead of crashing on matching.
+
+
+Version 3.3 01-Aug-00
+---------------------
+
+1. If an octal character was given, but the value was greater than \377, it
+was not getting masked to the least significant bits, as documented. This could
+lead to crashes in some systems.
+
+2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
+the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
+
+3. Added the functions pcre_free_substring() and pcre_free_substring_list().
+These just pass their arguments on to (pcre_free)(), but they are provided
+because some uses of PCRE bind it to non-C systems that can call its functions,
+but cannot call free() or pcre_free() directly.
+
+4. Add "make test" as a synonym for "make check". Corrected some comments in
+the Makefile.
+
+5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
+Makefile.
+
+6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
+command called pgrep for grepping around the active processes.
+
+7. Added the beginnings of support for UTF-8 character strings.
+
+8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
+RANLIB to ./ltconfig so that they are used by libtool. I think these are all
+the relevant ones. (AR is not passed because ./ltconfig does its own figuring
+out for the ar command.)
+
+
+Version 3.2 12-May-00
+---------------------
+
+This is purely a bug fixing release.
+
+1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
+of ZA. This was just one example of several cases that could provoke this bug,
+which was introduced by change 9 of version 2.00. The code for breaking
+infinite loops after an iteration that matches an empty string was't working
+correctly.
+
+2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
+when matched against abbab (for example). After matching an empty string, it
+wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
+caused it to match further down the string than it should.
+
+3. The code contained an inclusion of sys/types.h. It isn't clear why this
+was there because it doesn't seem to be needed, and it causes trouble on some
+systems, as it is not a Standard C header. It has been removed.
+
+4. Made 4 silly changes to the source to avoid stupid compiler warnings that
+were reported on the Macintosh. The changes were from
+
+  while ((c = *(++ptr)) != 0 && c != '\n');
+to
+  while ((c = *(++ptr)) != 0 && c != '\n') ;
+
+Totally extraordinary, but if that's what it takes...
+
+5. PCRE is being used in one environment where neither memmove() nor bcopy() is
+available. Added HAVE_BCOPY and an autoconf test for it; if neither
+HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
+assumes the way PCRE uses memmove() (always moving upwards).
+
+6. PCRE is being used in one environment where strchr() is not available. There
+was only one use in pcre.c, and writing it out to avoid strchr() probably gives
+faster code anyway.
+
+
+Version 3.1 09-Feb-00
+---------------------
+
+The only change in this release is the fixing of some bugs in Makefile.in for
+the "install" target:
+
+(1) It was failing to install pcreposix.h.
+
+(2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
+
+
+Version 3.0 01-Feb-00
+---------------------
+
+1. Add support for the /+ modifier to perltest (to output $` like it does in
+pcretest).
+
+2. Add support for the /g modifier to perltest.
+
+3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
+matches null strings.
+
+4. Fix perltest so that it doesn't do unwanted things when fed an empty
+pattern. Perl treats empty patterns specially - it reuses the most recent
+pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
+effect.
+
+5. The POSIX interface was broken in that it was just handing over the POSIX
+captured string vector to pcre_exec(), but (since release 2.00) PCRE has
+required a bigger vector, with some working space on the end. This means that
+the POSIX wrapper now has to get and free some memory, and copy the results.
+
+6. Added some simple autoconf support, placing the test data and the
+documentation in separate directories, re-organizing some of the
+information files, and making it build pcre-config (a GNU standard). Also added
+libtool support for building PCRE as a shared library, which is now the
+default.
+
+7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
+09 are not valid octal constants. Single digits will be used for minor values
+less than 10.
+
+8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
+existing programs that set these in the POSIX interface can use PCRE without
+modification.
+
+9. Added a new function, pcre_fullinfo() with an extensible interface. It can
+return all that pcre_info() returns, plus additional data. The pcre_info()
+function is retained for compatibility, but is considered to be obsolete.
+
+10. Added experimental recursion feature (?R) to handle one common case that
+Perl 5.6 will be able to do with (?p{...}).
+
+11. Added support for POSIX character classes like [:alpha:], which Perl is
+adopting.
+
+
+Version 2.08 31-Aug-99
+----------------------
+
+1. When startoffset was not zero and the pattern began with ".*", PCRE was not
+trying to match at the startoffset position, but instead was moving forward to
+the next newline as if a previous match had failed.
+
+2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
+and could get into a loop if a null string was matched other than at the start
+of the subject.
+
+3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
+be distinguished at compile time, and for completeness also added PCRE_DATE.
+
+5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
+in GnuWin32 environments.
+
+
+Version 2.07 29-Jul-99
+----------------------
+
+1. The documentation is now supplied in plain text form and HTML as well as in
+the form of man page sources.
+
+2. C++ compilers don't like assigning (void *) values to other pointer types.
+In particular this affects malloc(). Although there is no problem in Standard
+C, I've put in casts to keep C++ compilers happy.
+
+3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
+should be (const char *).
+
+4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
+be useful for non-Unix systems who don't want to bother with the POSIX stuff.
+However, I haven't made this a standard facility. The documentation doesn't
+mention it, and the Makefile doesn't support it.
+
+5. The Makefile now contains an "install" target, with editable destinations at
+the top of the file. The pcretest program is not installed.
+
+6. pgrep -V now gives the PCRE version number and date.
+
+7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
+causing the entire string to be ignored, instead of just the last character.
+
+8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
+non-matching string, it can take a very, very long time, even for strings of
+quite modest length, because of the nested recursion. PCRE now does better in
+some of these cases. It does this by remembering the last required literal
+character in the pattern, and pre-searching the subject to ensure it is present
+before running the real match. In other words, it applies a heuristic to detect
+some types of certain failure quickly, and in the above example, if presented
+with a string that has no trailing " it gives "no match" very quickly.
+
+9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
+other alternatives are tried instead.
+
+
+Version 2.06 09-Jun-99
+----------------------
+
+1. Change pcretest's output for amount of store used to show just the code
+space, because the remainder (the data block) varies in size between 32-bit and
+64-bit systems.
+
+2. Added an extra argument to pcre_exec() to supply an offset in the subject to
+start matching at. This allows lookbehinds to work when searching for multiple
+occurrences in a string.
+
+3. Added additional options to pcretest for testing multiple occurrences:
+
+   /+   outputs the rest of the string that follows a match
+   /g   loops for multiple occurrences, using the new startoffset argument
+   /G   loops for multiple occurrences by passing an incremented pointer
+
+4. PCRE wasn't doing the "first character" optimization for patterns starting
+with \b or \B, though it was doing it for other lookbehind assertions. That is,
+it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
+the letter 'x'. On long subject strings, this gives a significant speed-up.
+
+
+Version 2.05 21-Apr-99
+----------------------
+
+1. Changed the type of magic_number from int to long int so that it works
+properly on 16-bit systems.
+
+2. Fixed a bug which caused patterns starting with .* not to work correctly
+when the subject string contained newline characters. PCRE was assuming
+anchoring for such patterns in all cases, which is not correct because .* will
+not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
+DOTALL is set at top level; otherwise it knows that patterns starting with .*
+must be retried after every newline in the subject.
+
+
+Version 2.04 18-Feb-99
+----------------------
+
+1. For parenthesized subpatterns with repeats whose minimum was zero, the
+computation of the store needed to hold the pattern was incorrect (too large).
+If such patterns were nested a few deep, this could multiply and become a real
+problem.
+
+2. Added /M option to pcretest to show the memory requirement of a specific
+pattern. Made -m a synonym of -s (which does this globally) for compatibility.
+
+3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
+compiled in such a way that the backtracking after subsequent failure was
+pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
+((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
+
+
+Version 2.03 02-Feb-99
+----------------------
+
+1. Fixed typo and small mistake in man page.
+
+2. Added 4th condition (GPL supersedes if conflict) and created separate
+LICENCE file containing the conditions.
+
+3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
+Perl, that is the internal \ allows the delimiter to be included in the
+pattern. Locked out the use of \ as a delimiter. If \ immediately follows
+the final delimiter, add \ to the end of the pattern (to test the error).
+
+4. Added the convenience functions for extracting substrings after a successful
+match. Updated pcretest to make it able to test these functions.
+
 
 Version 2.02 14-Jan-99
 ----------------------