1. There has been some re-arrangement of the code for the match() function so
that it can be compiled in a version that does not call itself recursively.
Instead, it keeps those local variables that need separate instances for
each "recursion" in a frame on the heap, and gets/frees frames whenever it
needs to "recurse". Keeping track of where control must go is done by means
of setjmp/longjmp. The whole thing is implemented by a set of macros that
hide most of the details from the main code, and operates only if
NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
"configure" mechanism, "--disable-stack-for-recursion" turns on this way of
operating.
To make it easier for callers to provide specially tailored get/free
functions for this usage, two new functions, pcre_stack_malloc, and
pcre_stack_free, are used. They are always called in strict stacking order,
and the size of block requested is always the same.
The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
PCRE has been compiled to use the stack or the heap for recursion. The
-C option of pcretest uses this to show which version is compiled.
A new data escape \S, is added to pcretest; it causes the amounts of store
obtained and freed by both kinds of malloc/free at match time to be added
to the output.
2. Changed the locale test to use "fr_FR" instead of "fr" because that's
what's available on my current Linux desktop machine.
3. When matching a UTF-8 string, the test for a valid string at the start has
been extended. If start_offset is not zero, PCRE now checks that it points
to a byte that is the start of a UTF-8 character. If not, it returns
PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
this is necessary because there may be backward assertions in the pattern.
When matching the same subject several times, it may save resources to use
PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4. The code for checking the validity of UTF-8 strings has been tightened so
that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
containing "overlong sequences".
5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
should have been "&", but it just so happened that all the cases this let
through by mistake were picked up later in the function.
6. I had used a variable called "isblank" - this is a C99 function, causing
some compilers to warn. To avoid this, I renamed it (as "blankclass").
7. Cosmetic: (a) only output another newline at the end of pcretest if it is
prompting; (b) run "./pcretest /dev/null" at the start of the test script
so the version is shown; (c) stop "make test" echoing "./RunTest".
8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
9. The prototype for memmove() for systems that don't have it was using
size_t, but the inclusion of the header that defines size_t was later. I've
moved the #includes for the C headers earlier to avoid this.
10. Added some adjustments to the code to make it easier to compiler on certain
special systems:
(a) Some "const" qualifiers were missing.
(b) Added the macro EXPORT before all exported functions; by default this
is defined to be empty.
(c) Changed the dftables auxiliary program (that builds chartables.c) so
that it reads its output file name as an argument instead of writing
to the standard output and assuming this can be redirected.
11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
class containing characters with values greater than 255, PCRE compilation
went into a loop.
12. A recursive reference to a subpattern that was within another subpattern
that had a minimum quantifier of zero caused PCRE to crash. For example,
(x(y(?2))z)? provoked this bug with a subject that got as far as the
recursion. If the recursively-called subpattern itself had a zero repeat,
that was OK.
13. In pcretest, the buffer for reading a data line was set at 30K, but the
buffer into which it was copied (for escape processing) was still set at
1024, so long lines caused crashes.
14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
"internal error: code overflow...". This applied to any character class
that was followed by a possessive quantifier.
15. Modified the Makefile to add libpcre.la as a prerequisite for
libpcreposix.la because I was told this is needed for a parallel build to
work.
16. If a pattern that contained .* following optional items at the start was
studied, the wrong optimizing data was generated, leading to matching
errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
matching string must start with a or b or c. The correct conclusion for
this pattern is that a match can start with any character.
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