The attached stuff is a patch for PR 10728: 
http://sourceware.org/bugzilla/show_bug.cgi?id=10728 "infinite loop 
evaluating pointer difference w/o complete debug info"

The bug was in valarith.c : value_ptrdiff--if the type structs showed 
size == 0, things came unstuck.  This patch fixes that by issuing a 
warning and assuming size = 1.

The patch includes testcase source files and and an expects file.

The gdb.sum diff between the unpatched and patched make check is also 
attached.

Chris Moller,
Red Hat