* xrdb.c: Don't assume strlen fits in int; avoid some strlens.

* xrdb.c: Don't assume strlen fits in int; avoid some strlens.

* xrdb.c (magic_file_p, search_magic_path):
Omit last arg SUFFIX; it was always 0.  All callers changed.
(magic_file_p): Use ptrdiff_t, not int.  Check for size overflow.