Nick Ing-Simmons <nick(_at_)ing-simmons(_dot_)net> writes:
While (on the other machine) Tk804 seems happy-ish, on
this laptop I am attempting to catch up on my mail
using bleadperl + UTF8-aware tkmail but non Unicode Tk800.
It seems to be discovering a snag.
When I try and read Autrijus Tang's latest posting to
perl-unicode with that I get a malloc related segfault:
Note that in _this_ case use of tkmail is using fallbacks - so I suspect
(no proof yet) that "new" fallback insert can buffer-overrun, and so destroy
the malloc data structures.
This looks suspicious:
Near line 181 of Encode.xs (tail of main while loop):
/* settle variables when fallback */
dlen = SvCUR(dst);
d = (U8*)SvPVX(dst) + dlen;
s = (U8*)SvPVX(src) + sdone;
slen = tlen - sdone;
break;
When calling do_encode() at top of loop dlen is supposed to be number
of bytes _available_ at d, and you have it as number of bytes _used_.
So if we have used most of it and then insert a fallback do_encode()
will zoom off the end of the SV.
I think (too late here for morning person like me to think well) that
d = (U8 *) SvEND(dst);
dlen = SvLEN(dst) - ddone - 1;
is closer to correct ..
--
Nick Ing-Simmons
http://www.ni-s.u-net.com/
