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-revision 67 by nigel,
Sat Feb 24 21:40:13 2007 UTC
+revision 373 by ph10,
Fri Sep  5 10:25:46 2008 UTC
 Line 1
  ChangeLog for PCRE
  ------------------
+ Version 7.8 25-Aug-08
+ ---------------------
+.  Replaced UCP searching code with optimized version as implemented for Ad
+     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
+     stage table and inline lookup instead of a function, giving speed ups of 2
+     to 5 times on some simple patterns that I tested. Permission was given to
+     distribute the MultiStage2.py script that generates the tables (it's not in
+     the tarball, but is in the Subversion repository).
+.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
+     scripts.
+.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
+     a group with a zero qualifier. The result of the study could be incorrect,
+     or the function might crash, depending on the pattern.
+.  Caseless matching was not working for non-ASCII characters in back
+     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
+     It now works when Unicode Property Support is available.
+.  In pcretest, an escape such as \x{de} in the data was always generating
+     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
+     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
+     truncation.
+.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
+.  Added two (int) casts to pcregrep when printing the difference of two
+     pointers, in case they are 64-bit values.
+.  Added comments about Mac OS X stack usage to the pcrestack man page and to
+     test 2 if it fails.
+.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
+     and a #define of that name to empty if it is not externally set. This is to
+     allow users of MSVC to set it if necessary.
+. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
+     the convenience functions in the pcre_get.c source file.
+. An option change at the start of a pattern that had top-level alternatives
+     could cause overwriting and/or a crash. This command provoked a crash in
+     some environments:
+       printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
+     This potential security problem was recorded as CVE-2008-2371.
+. For a pattern where the match had to start at the beginning or immediately
+     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
+     pcre_dfa_exec() could read past the end of the passed subject if there was
+     no match. To help with detecting such bugs (e.g. with valgrind), I modified
+     pcretest so that it places the subject at the end of its malloc-ed buffer.
+. The change to pcretest in 12 above threw up a couple more cases when pcre_
+     exec() might read past the end of the data buffer in UTF-8 mode.
+. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
+     the data contained the byte 0x85 as part of a UTF-8 character within its
+     first line. This applied both to normal and DFA matching.
+. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
+     /^[^d]*?$/8 failed to match "abc".
+. Added a missing copyright notice to pcrecpp_internal.h.
+. Make it more clear in the documentation that values returned from
+     pcre_exec() in ovector are byte offsets, not character counts.
+. Tidied a few places to stop certain compilers from issuing warnings.
+. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
+     supplied by Stefan Weber. I made a further small update for 7.8 because
+     there is a change of source arrangements: the pcre_searchfuncs.c module is
+     replaced by pcre_ucd.c.
+ Version 7.7 07-May-08
+ ---------------------
+.  Applied Craig's patch to sort out a long long problem: "If we can't convert
+     a string to a long long, pretend we don't even have a long long." This is
+     done by checking for the strtoq, strtoll, and _strtoi64 functions.
+.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
+     pre-7.6 versions, which defined a global no_arg variable instead of putting
+     it in the RE class. (See also #8 below.)
+.  Remove a line of dead code, identified by coverity and reported by Nuno
+     Lopes.
+.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
+     (1) The include/exclude patterns were being applied to the whole pathnames
+         of files, instead of just to the final components.
+     (2) If there was more than one level of directory, the subdirectories were
+         skipped unless they satisfied the include/exclude conditions. This is
+         inconsistent with GNU grep (and could even be seen as contrary to the
+         pcregrep specification - which I improved to make it absolutely clear).
+         The action now is always to scan all levels of directory, and just
+         apply the include/exclude patterns to regular files.
+.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
+     --exclude_dir in the tests to avoid scanning .svn directories.
+.  Applied Craig's patch to the QuoteMeta function so that it escapes the
+     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
+     doesn't support NULs in patterns.
+.  Added some missing "const"s to declarations of static tables in
+     pcre_compile.c and pcre_dfa_exec.c.
+.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
+     caused by fix #2  above. (Subsequently also a second patch to fix the
+     first patch. And a third patch - this was a messy problem.)
+.  Applied Craig's patch to remove the use of push_back().
+. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
+     matching function regexec().
+. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
+     which, however, unlike Perl's \g{...}, are subroutine calls, not back
+     references. PCRE supports relative numbers with this syntax (I don't think
+     Oniguruma does).
+. Previously, a group with a zero repeat such as (...){0} was completely
+     omitted from the compiled regex. However, this means that if the group
+     was called as a subroutine from elsewhere in the pattern, things went wrong
+     (an internal error was given). Such groups are now left in the compiled
+     pattern, with a new opcode that causes them to be skipped at execution
+     time.
+. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
+     to the way PCRE behaves:
+     (a) A lone ] character is dis-allowed (Perl treats it as data).
+     (b) A back reference to an unmatched subpattern matches an empty string
+         (Perl fails the current match path).
+     (c) A data ] in a character class must be notated as \] because if the
+         first data character in a class is ], it defines an empty class. (In
+         Perl it is not possible to have an empty class.) The empty class []
+         never matches; it forces failure and is equivalent to (*FAIL) or (?!).
+         The negative empty class [^] matches any one character, independently
+         of the DOTALL setting.
+. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
+     non-existent subpattern following a character class starting with ']' and
+     containing () gave an internal compiling error instead of "reference to
+     non-existent subpattern". Fortunately, when the pattern did exist, the
+     compiled code was correct. (When scanning forwards to check for the
+     existencd of the subpattern, it was treating the data ']' as terminating
+     the class, so got the count wrong. When actually compiling, the reference
+     was subsequently set up correctly.)
+. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
+     it was being rejected as not supported by pcre_dfa_exec(), even though
+     other assertions are supported. I have made pcre_dfa_exec() support
+     (*FAIL).
+. The implementation of 13c above involved the invention of a new opcode,
+     OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
+     cannot be changed at match time, I realized I could make a small
+     improvement to matching performance by compiling OP_ALLANY instead of
+     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
+     on the OP_ANY path.
+. Compiling pcretest on Windows with readline support failed without the
+     following two fixes: (1) Make the unistd.h include conditional on
+     HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
+. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
+     ncurses library to be included for pcretest when ReadLine support is
+     requested, but also to allow for it to be overridden. This patch came from
+     Daniel Bergstr�m.
+. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
+     as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
+     any errors with the current Unicode tables. Thanks to Peter Kankowski for
+     spotting this.
+ Version 7.6 28-Jan-08
+ ---------------------
+.  A character class containing a very large number of characters with
+     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
+     overflow.
+.  Patch to cut out the "long long" test in pcrecpp_unittest when
+     HAVE_LONG_LONG is not defined.
+.  Applied Christian Ehrlicher's patch to update the CMake build files to
+     bring them up to date and include new features. This patch includes:
+     - Fixed PH's badly added libz and libbz2 support.
+     - Fixed a problem with static linking.
+     - Added pcredemo. [But later removed - see 7 below.]
+     - Fixed dftables problem and added an option.
+     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
+         HAVE_LONG_LONG.
+     - Added readline support for pcretest.
+     - Added an listing of the option settings after cmake has run.
+.  A user submitted a patch to Makefile that makes it easy to create
+     "pcre.dll" under mingw when using Configure/Make. I added stuff to
+     Makefile.am that cause it to include this special target, without
+     affecting anything else. Note that the same mingw target plus all
+     the other distribution libraries and programs are now supported
+     when configuring with CMake (see 6 below) instead of with
+     Configure/Make.
+.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
+     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
+     exported in the Windows port". It has not yet been confirmed that the patch
+     solves the problem, but it does no harm.
+.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
+     NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
+     with CMake, and also correct the comment about stack recursion.
+.  Remove the automatic building of pcredemo from the ./configure system and
+     from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
+     of a program that users should build themselves after PCRE is installed, so
+     building it automatically is not really right. What is more, it gave
+     trouble in some build environments.
+.  Further tidies to CMakeLists.txt from Sheri and Christian.
+ Version 7.5 10-Jan-08
+ ---------------------
+.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
+     values in parens when parsing an RE using the C++ wrapper."
+.  Negative specials like \S did not work in character classes in UTF-8 mode.
+     Characters greater than 255 were excluded from the class instead of being
+     included.
+.  The same bug as (2) above applied to negated POSIX classes such as
+     [:^space:].
+.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
+     defined or documented. It seems to have been a typo for PCRE_STATIC, so
+     I have changed it.
+.  The construct (?&) was not diagnosed as a syntax error (it referenced the
+     first named subpattern) and a construct such as (?&a) would reference the
+     first named subpattern whose name started with "a" (in other words, the
+     length check was missing). Both these problems are fixed. "Subpattern name
+     expected" is now given for (?&) (a zero-length name), and this patch also
+     makes it give the same error for \k'' (previously it complained that that
+     was a reference to a non-existent subpattern).
+.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
+     this is right because (?- can be followed by option settings as well as by
+     digits. I have, however, made the messages clearer.
+.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
+     than the number used in the conditional) now cause a compile-time error.
+     This is actually not compatible with Perl, which accepts such patterns, but
+     treats the conditional as always being FALSE (as PCRE used to), but it
+     seems to me that giving a diagnostic is better.
+.  Change "alphameric" to the more common word "alphanumeric" in comments
+     and messages.
+.  Fix two occurrences of "backslash" in comments that should have been
+     "backspace".
+. Remove two redundant lines of code that can never be obeyed (their function
+     was moved elsewhere).
+. The program that makes PCRE's Unicode character property table had a bug
+     which caused it to generate incorrect table entries for sequences of
+     characters that have the same character type, but are in different scripts.
+     It amalgamated them into a single range, with the script of the first of
+     them. In other words, some characters were in the wrong script. There were
+     thirteen such cases, affecting characters in the following ranges:
+       U+002b0 - U+002c1
+       U+0060c - U+0060d
+       U+0061e - U+00612
+       U+0064b - U+0065e
+       U+0074d - U+0076d
+       U+01800 - U+01805
+       U+01d00 - U+01d77
+       U+01d9b - U+01dbf
+       U+0200b - U+0200f
+       U+030fc - U+030fe
+       U+03260 - U+0327f
+       U+0fb46 - U+0fbb1
+       U+10450 - U+1049d
+. The -o option (show only the matching part of a line) for pcregrep was not
+     compatible with GNU grep in that, if there was more than one match in a
+     line, it showed only the first of them. It now behaves in the same way as
+     GNU grep.
+. If the -o and -v options were combined for pcregrep, it printed a blank
+     line for every non-matching line. GNU grep prints nothing, and pcregrep now
+     does the same. The return code can be used to tell if there were any
+     non-matching lines.
+. Added --file-offsets and --line-offsets to pcregrep.
+. The pattern (?=something)(?R) was not being diagnosed as a potentially
+     infinitely looping recursion. The bug was that positive lookaheads were not
+     being skipped when checking for a possible empty match (negative lookaheads
+     and both kinds of lookbehind were skipped).
+. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
+     inclusion of <windows.h> to before rather than after the definition of
+     INVALID_FILE_ATTRIBUTES (patch from David Byron).
+. Specifying a possessive quantifier with a specific limit for a Unicode
+     character property caused pcre_compile() to compile bad code, which led at
+     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
+     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
+     caused the error; without that there was no problem.
+. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
+. Added --enable-pcretest-libreadline.
+. In pcrecpp.cc, the variable 'count' was incremented twice in
+     RE::GlobalReplace(). As a result, the number of replacements returned was
+     double what it should be. I removed one of the increments, but Craig sent a
+     later patch that removed the other one (the right fix) and added unit tests
+     that check the return values (which was not done before).
+. Several CMake things:
+     (1) Arranged that, when cmake is used on Unix, the libraries end up with
+         the names libpcre and libpcreposix, not just pcre and pcreposix.
+     (2) The above change means that pcretest and pcregrep are now correctly
+         linked with the newly-built libraries, not previously installed ones.
+     (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
+. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
+     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
+     UTF-8 newline character). The key issue is that the pattern starts .*;
+     this means that the match must be either at the beginning, or after a
+     newline. The bug was in the code for advancing after a failed match and
+     checking that the new position followed a newline. It was not taking
+     account of UTF-8 characters correctly.
+. PCRE was behaving differently from Perl in the way it recognized POSIX
+     character classes. PCRE was not treating the sequence [:...:] as a
+     character class unless the ... were all letters. Perl, however, seems to
+     allow any characters between [: and :], though of course it rejects as
+     unknown any "names" that contain non-letters, because all the known class
+     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
+     for example, whereas PCRE did not - it did not recognize a POSIX character
+     class. This seemed a bit dangerous, so the code has been changed to be
+     closer to Perl. The behaviour is not identical to Perl, because PCRE will
+     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
+     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
+     Perl does, and where it didn't before.
+. Rewrite so as to remove the single use of %n from pcregrep because in some
+     Windows environments %n is disabled by default.
+ Version 7.4 21-Sep-07
+ ---------------------
+.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
+     means that a class such as [\s] counted as "explicit reference to CR or
+     LF". That isn't really right - the whole point of the change was to try to
+     help when there was an actual mention of one of the two characters. So now
+     the change happens only if \r or \n (or a literal CR or LF) character is
+     encountered.
+.  The 32-bit options word was also used for 6 internal flags, but the numbers
+     of both had grown to the point where there were only 3 bits left.
+     Fortunately, there was spare space in the data structure, and so I have
+     moved the internal flags into a new 16-bit field to free up more option
+     bits.
+.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
+     but did not set the internal JCHANGED flag - either of these is enough to
+     control the way the "get" function works - but the PCRE_INFO_JCHANGED
+     facility is supposed to tell if (?J) was ever used, so now (?J) at the
+     start sets both bits.
+.  Added options (at build time, compile time, exec time) to change \R from
+     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
+.  doc/pcresyntax.html was missing from the distribution.
+.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
+     compatibility, even though it is no longer used.
+.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
+     strtoull to pcrecpp.cc to select the available functions in WIN32 when the
+     windows.h file is present (where different names are used). [This was
+     reversed later after testing - see 16 below.]
+.  Changed all #include <config.h> to #include "config.h". There were also
+     some further <pcre.h> cases that I changed to "pcre.h".
+.  When pcregrep was used with the --colour option, it missed the line ending
+     sequence off the lines that it output.
+. It was pointed out to me that arrays of string pointers cause lots of
+     relocations when a shared library is dynamically loaded. A technique of
+     using a single long string with a table of offsets can drastically reduce
+     these. I have refactored PCRE in four places to do this. The result is
+     dramatic:
+       Originally:                          290
+       After changing UCP table:            187
+       After changing error message table:   43
+       After changing table of "verbs"       36
+       After changing table of Posix names   22
+     Thanks to the folks working on Gregex for glib for this insight.
+. --disable-stack-for-recursion caused compiling to fail unless -enable-
+     unicode-properties was also set.
+. Updated the tests so that they work when \R is defaulted to ANYCRLF.
+. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
+     checked only for CRLF.
+. Added casts to pcretest.c to avoid compiler warnings.
+. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
+. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
+     and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
+     entirely. This removes changes made in 7 above.
+. The CMake files have been updated, and there is now more information about
+     building with CMake in the NON-UNIX-USE document.
+ Version 7.3 28-Aug-07
+ ---------------------
+. In the rejigging of the build system that eventually resulted in 7.1, the
+     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
+     brackets there is not right, since it causes compilers to look for an
+     installed pcre.h, not the version that is in the source that is being
+     compiled (which of course may be different). I have changed it back to:
+       #include "pcre.h"
+     I have a vague recollection that the change was concerned with compiling in
+     different directories, but in the new build system, that is taken care of
+     by the VPATH setting the Makefile.
+. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
+     when the subject happened to end in the byte 0x85 (e.g. if the last
+     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
+     characters but of course it shouldn't be taken as a newline when it is part
+     of another character. The bug was that, for an unlimited repeat of . in
+     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
+     characters when looking for a newline.
+. A small performance improvement in the DOTALL UTF-8 mode .* case.
+. Debugging: adjusted the names of opcodes for different kinds of parentheses
+     in debug output.
+. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
+     long printing in the pcrecpp unittest when running under MinGW.
+. ESC_K was left out of the EBCDIC table.
+. Change 7.0/38 introduced a new limit on the number of nested non-capturing
+     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
+     limit also applies to "virtual nesting" when a pattern is recursive, and in
+     this case 1000 isn't so big. I have been able to remove this limit at the
+     expense of backing off one optimization in certain circumstances. Normally,
+     when pcre_exec() would call its internal match() function recursively and
+     immediately return the result unconditionally, it uses a "tail recursion"
+     feature to save stack. However, when a subpattern that can match an empty
+     string has an unlimited repetition quantifier, it no longer makes this
+     optimization. That gives it a stack frame in which to save the data for
+     checking that an empty string has been matched. Previously this was taken
+     from the 1000-entry workspace that had been reserved. So now there is no
+     explicit limit, but more stack is used.
+. Applied Daniel's patches to solve problems with the import/export magic
+     syntax that is required for Windows, and which was going wrong for the
+     pcreposix and pcrecpp parts of the library. These were overlooked when this
+     problem was solved for the main library.
+. There were some crude static tests to avoid integer overflow when computing
+     the size of patterns that contain repeated groups with explicit upper
+     limits. As the maximum quantifier is 65535, the maximum group length was
+     set at 30,000 so that the product of these two numbers did not overflow a
+-bit integer. However, it turns out that people want to use groups that
+     are longer than 30,000 bytes (though not repeat them that many times).
+     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
+     made it possible to implement the integer overflow checks in a much more
+     dynamic way, which I have now done. The artificial limitation on group
+     length has been removed - we now have only the limit on the total length of
+     the compiled pattern, which depends on the LINK_SIZE setting.
+. Fixed a bug in the documentation for get/copy named substring when
+     duplicate names are permitted. If none of the named substrings are set, the
+     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
+     empty string.
+. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
+     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
+     because the ] is interpreted as the first data character and the
+     terminating ] is not found. PCRE has been made compatible with Perl in this
+     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
+     cause memory overwriting.
+. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
+     string has been matched (to stop an infinite loop). It was not recognizing
+     a conditional subpattern that could match an empty string if that
+     subpattern was within another subpattern. For example, it looped when
+     trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
+     condition was not nested. This bug has been fixed.
+. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
+     past the start of the subject in the presence of bytes with the top bit
+     set, for example "\x8aBCD".
+. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
+     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
+. Optimized (?!) to (*FAIL).
+. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
+     This restricts code points to be within the range 0 to 0x10FFFF, excluding
+     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
+     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
+     does: it's just the validity check that is more restrictive.
+. Inserted checks for integer overflows during escape sequence (backslash)
+     processing, and also fixed erroneous offset values for syntax errors during
+     backslash processing.
+. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
+     for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
+. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
+     caused an overrun.
+. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
+     something other than just ASCII characters) inside a group that had an
+     unlimited repeat caused a loop at compile time (while checking to see
+     whether the group could match an empty string).
+. Debugging a pattern containing \p or \P could cause a crash. For example,
+     [\P{Any}] did so. (Error in the code for printing property names.)
+. An orphan \E inside a character class could cause a crash.
+. A repeated capturing bracket such as (A)? could cause a wild memory
+     reference during compilation.
+. There are several functions in pcre_compile() that scan along a compiled
+     expression for various reasons (e.g. to see if it's fixed length for look
+     behind). There were bugs in these functions when a repeated \p or \P was
+     present in the pattern. These operators have additional parameters compared
+     with \d, etc, and these were not being taken into account when moving along
+     the compiled data. Specifically:
+     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
+         length.
+     (b) An item such as \pL+ within a repeated group could cause crashes or
+         loops.
+     (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
+         "reference to non-existent subpattern" error.
+     (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
+. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
+     characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
+. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
+. Patterns such as [\P{Yi}A] which include \p or \P and just one other
+     character were causing crashes (broken optimization).
+. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
+     \p or \P) caused a compile-time loop.
+. More problems have arisen in unanchored patterns when CRLF is a valid line
+     break. For example, the unstudied pattern [\r\n]A does not match the string
+     "\r\nA" because change 7.0/46 below moves the current point on by two
+     characters after failing to match at the start. However, the pattern \nA
+     *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
+     the same is true. There doesn't seem any very clean way out of this, but
+     what I have chosen to do makes the common cases work: PCRE now takes note
+     of whether there can be an explicit match for \r or \n anywhere in the
+     pattern, and if so, 7.0/46 no longer applies. As part of this change,
+     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
+     pattern has explicit CR or LF references.
+. Added (*CR) etc for changing newline setting at start of pattern.
+ Version 7.2 19-Jun-07
+ ---------------------
+. If the fr_FR locale cannot be found for test 3, try the "french" locale,
+     which is apparently normally available under Windows.
+. Re-jig the pcregrep tests with different newline settings in an attempt
+     to make them independent of the local environment's newline setting.
+. Add code to configure.ac to remove -g from the CFLAGS default settings.
+. 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.
+. 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.
+. 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.
+. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
+     PCRE_INFO_JCHANGED.
+. 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.
+. 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.
+. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
+. 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.
+. If \p or \P was used in non-UTF-8 mode on a character greater than 127
+     it matched the wrong number of bytes.
+ Version 7.1 24-Apr-07
+ ---------------------
+. 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.
+. 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.
+. 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.
+. 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).
+. 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.
+. 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.
+. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
+     that is needed.
+. 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.
+. 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.
+. 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.
+. 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".
+. 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.
+. 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.)
+. If erroroffset was passed as NULL to pcre_compile, it provoked a
+     segmentation fault instead of returning the appropriate error message.
+. 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.
+. 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.
+. Under certain error circumstances pcregrep might try to free random memory
+     as it exited. This is now fixed, thanks to valgrind.
+. 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.
+. 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.
+. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
+     CRLF as a newline sequence.
+. 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.
+. Added some casts to kill warnings from HP-UX ia64 compiler.
+. Added a man page for pcre-config.
+ Version 7.0 19-Dec-06
+ ---------------------
+. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
+     moving to gcc 4.1.1.
+. 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.
+. It seems that there are systems where bytes whose values are greater than
+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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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).
+. 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
+.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.
+. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
+. Added -help and --help to pcretest as an official way of being reminded
+     of the options.
+. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
+     and pcrecpp.cc because they annoy compilers at high warning levels.
+. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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).
+. 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".
+. 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().
+. Realized that a little bit of performance could be had by replacing
+     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
+. Timing data from pcretest is now shown to 4 decimal places instead of 3.
+. 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.
+. 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.
+. The ucpinternal.h header file was missing its idempotency #ifdef.
+. 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.
+. 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.
+. 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.
+. "Subroutine" calls and backreferences were previously restricted to
+     referencing subpatterns earlier in the regex. This restriction has now
+     been removed.
+. 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
+.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.
+. Tidied to get rid of some further signed/unsigned compiler warnings and
+     some "unreachable code" warnings.
+. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
+     things, this adds five new scripts.
+. 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.
+. 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.
+. 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).
+. 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.
+. Add \R to match any Unicode newline sequence, as suggested in the Unicode
+     report.
+. Applied patch, originally from Ari Pollak, modified by Google, to allow
+     copy construction and assignment in the C++ wrapper.
+. 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.
+. 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.
+. 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.
+. 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
+ ---------------------
+. 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.
+. 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.)
+. 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.
+. 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.]
+. 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".
+. 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.
+. 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.
+. 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.
+. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
+     instance of the 'standard' template library not being so standard".
+. 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.
+. 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
+, 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.
+. Added the optional facility to have named substrings with the same name.
+. 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.
+. Added forward references in named backreferences (if you see what I mean).
+. 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".
+. 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 *.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. Changed the definition of CXXLINK to make it agree with the definition of
+     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
+. 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.
+. 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.
+. Applied patches from Google (a) to support the new newline modes and (b) to
+     advance over multibyte UTF-8 characters in GlobalReplace.
+. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
+     difference for some implementation of PCRE in some Windows version.
+. 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
+ ---------------------
+. 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.
+. Change 25 for 6.5 broke compilation in a build directory out-of-tree
+     because pcre.h is no longer a built file.
+. Added Jeff Friedl's additional debugging patches to pcregrep. These are
+     not normally included in the compiled code.
+ Version 6.5 01-Feb-06
+ ---------------------
+. 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.
+. 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.
+. 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)).
+. 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.)
+. 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.
+. 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.
+. 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.
+. 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).
+. 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.
+. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
+. 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.
+. 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.
+. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
+     C++ linking (needed for some HP-UX environments).
+. 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).
+. 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.
+. 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.)
+. 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.
+. 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}.
+. In UTF-8 mode, a backslash followed by a non-Ascii character was not
+     matching that character.
+. 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.
+. 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.
+. Added "Any" and "L&" to the supported property types.
+. 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.
+. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
+     accidentally not being installed or uninstalled.
+. 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.
+. Added the ability to run the tests under valgrind.
+ Version 6.4 05-Sep-05
+ ---------------------
+. 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.
+. A couple of code tidies to get rid of compiler warnings.
+. 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.
+. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
+     file's purpose clearer.
+. Reorganized pcre_ucp_findchar().
+ Version 6.3 15-Aug-05
+ ---------------------
+. The file libpcre.pc.in did not have general read permission in the tarball.
+. 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.)
+. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
+     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
+     necessary on certain architectures.
+. 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
+ ---------------------
+. 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.
+. Building PCRE using VPATH was broken. Hopefully it is now fixed.
+. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
+     operating environments where this matters.
+. Applied Giuseppe Maxia's patch to add additional features for controlling
+     PCRE options from within the C++ wrapper.
+. 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.
+. 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
+ ---------------------
+. There was one reference to the variable "posix" in pcretest.c that was not
+     surrounded by "#if !defined NOPOSIX".
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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
+ ---------------------
+. Some minor internal re-organization to help with my DFA experiments.
+. 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.
+. 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.
+. 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.
+. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
+     including restarting after a partial match.
+. 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.
+. Added the pcre_refcount() auxiliary function.
+. 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.
+. 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.
+. 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
+K, 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.
+. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
+     Hopefully, it now does.
+. Missing cast in pcre_study().
+. Added an "uninstall" target to the makefile.
+. 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.
+. 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.
+. 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.)
+. 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.
+. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
+. libpcre.pc was being incorrectly installed as executable.
+. 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.
+. Added Google's contributed C++ wrapper to the distribution.
+. Added some untidy missing memory free() calls in pcretest, to keep
+     Electric Fence happy when testing.
+ Version 5.0 13-Sep-04
+ ---------------------
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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.
+. Added support for pkg-config (2 patches were sent in).
+. 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.
+. 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.
+. 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.
+. 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.)
+. 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.
+. Modified the pcre-config script so that, when run on Solaris, it shows a
+     -R library as well as a -L library.
+. 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.
+. 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.
+. Updated pcredemo.c to include calls to free() to release the memory for the
+     compiled pattern.
+. 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.
+. 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.
+. Added support for partial matching via the PCRE_PARTIAL option for
+     pcre_exec() and the \P data escape in pcretest.
+. 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.
+. 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.
+. 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.
+. 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).
+. Changed the PCRE licence to be the more standard "BSD" licence.
+ Version 4.5 01-Dec-03
+ ---------------------
+. 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.
+. Changed the locale test to use "fr_FR" instead of "fr" because that's
+     what's available on my current Linux desktop machine.
+. 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.
+. 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".
+. 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.
+. 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").
+. 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".
+. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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
+, so long lines caused crashes.
+. 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.
+. 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.
+. 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
+ ---------------------
+. In UTF-8 mode, a character class containing characters with values between
+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).
+. Three internal functions had redundant arguments passed to them. Removal
+     might give a very teeny performance improvement.
+. Documentation bug: the value of the capture_top field in a callout is *one
+     more than* the number of the hightest numbered captured substring.
+. 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.
+. configure.in no longer needs to recognize Cygwin specially.
+. A problem in pcre.in for Windows platforms is fixed.
+. 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.
+. 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.
+. 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.
+. 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.
+. 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
+ ---------------------
+. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
+    Makefile.
+. 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.
+. The first argument for regexec() in the POSIX wrapper should have been
+    defined as "const".
+. Changed pcretest to use malloc() for its buffers so that they can be
+    Electric Fenced for debugging.
+. 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.
+. 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.
+. 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
  ---------------------

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