* Determine whether the specified message number is contained within the specified set.
* Returns nonzero if the specified message number is in the specified message set string.
*/
-int is_msg_in_mset(char *mset, long msgnum) {
+int is_msg_in_mset(const char *mset, long msgnum) {
int num_sets;
int s;
char setstr[SIZ], lostr[SIZ], histr[SIZ]; /* was 1024 */