Add a test for the latest select decoding fix

* test/select.c (main): Add a test for nfds larger than FD_SETSIZE.

test/select.c

@@ -11,13 +11,24 @@ char buffer[1024*1024*2];
 int main()
 {
 	fd_set rds;
+	struct timeval timeout;
+
 	FD_ZERO(&rds);
 	FD_SET(2, &rds);
 	/* Start with a nice simple select */
 	select(3, &rds, &rds, &rds, NULL);
+
 	/* Now the crash case that trinity found, negative nfds
 	 * but with a pointer to a large chunk of valid memory.
 	 */
+	FD_ZERO((fd_set*)buffer);
+	FD_SET(2,(fd_set*)buffer);
 	select(-1, (fd_set *)buffer, NULL, NULL, NULL);
+
+	/* Another variant, with nfds exceeding allowed limit. */
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 100;
+	select(FD_SETSIZE + 1, (fd_set *)buffer, NULL, NULL, &timeout);
+
 	return 0;
 }