From the strncpy(3) manpage:

The strings may not overlap, and the destination string dest must be large 
enough to receive the copy.

http://bugs.gentoo.org/104311

--- ftp/ftp.c
+++ ftp/ftp.c
@@ -1808,7 +1808,7 @@
 	}
 	ip->connect = connected;
 	connected = op->connect;
-	if (hostname) {
+	if (hostname && ip->name != hostname) {
 		(void) strncpy(ip->name, hostname, sizeof(ip->name) - 1);
 		ip->name[sizeof(ip->name) - 1] = '\0';
 	}