test-memchr failure on rawhide

[Jim Meyering]

FYI, while doing pre-release testing for coreutils-7.4, I noticed a
single gnulib test failure on Fedora rawhide.  It looks like a bug in
<string.h>'s memchr macro.  Reported here:

    http://bugzilla.redhat.com/499689

Quick summary:

cat > k.c <<\EOF
#include <string.h>
int main() { return !!(memchr (0, 'a', 0)); }
EOF
gcc -O k.c; ./a.out
Segmentation fault
[Exit 139 (SIGSEGV)]

It's not a problem on Fedora 10.