Fix DNSSEC and DNAME.

Do the correct things to validate replies which
include a DNAME record.

Thanks to Graham Clinch for pointing this out.

src/util.c

@@ -426,7 +426,7 @@ int hostname_order(const char *a, const char *b)
 
 int hostname_isequal(const char *a, const char *b)
 {
-  return hostname_order(a, b) == 0;
+  return strlen(a) == strlen(b) && hostname_order(a, b) == 0;
 }
 
 /* is b equal to or a subdomain of a return 2 for equal, 1 for subdomain */