===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/input.c,v
retrieving revision 1.123
retrieving revision 1.124
diff -u -r1.123 -r1.124
--- src/usr.bin/tmux/input.c	2017/06/03 17:43:01	1.123
+++ src/usr.bin/tmux/input.c	2017/06/04 09:02:36	1.124
@@ -1,4 +1,4 @@
-/* $OpenBSD: input.c,v 1.123 2017/06/03 17:43:01 nicm Exp $ */
+/* $OpenBSD: input.c,v 1.124 2017/06/04 09:02:36 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1896,8 +1896,10 @@
 	switch (option) {
 	case 0:
 	case 2:
-		screen_set_title(ictx->ctx.s, p);
-		server_status_window(ictx->wp->window);
+		if (utf8_isvalid(p)) {
+			screen_set_title(ictx->ctx.s, p);
+			server_status_window(ictx->wp->window);
+		}
 		break;
 	case 4:
 		input_osc_4(ictx->wp, p);
@@ -1909,7 +1911,7 @@
 		input_osc_11(ictx->wp, p);
 		break;
 	case 12:
-		if (*p != '?') /* ? is colour request */
+		if (utf8_isvalid(p) && *p != '?') /* ? is colour request */
 			screen_set_cursor_colour(ictx->ctx.s, p);
 		break;
 	case 52:
@@ -1945,6 +1947,8 @@
 		return;
 	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
 
+	if (!utf8_isvalid(ictx->input_buf))
+		return;
 	screen_set_title(ictx->ctx.s, ictx->input_buf);
 	server_status_window(ictx->wp->window);
 }
@@ -1968,9 +1972,10 @@
 		return;
 	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
 
+	if (!utf8_isvalid(ictx->input_buf))
+		return;
 	window_set_name(ictx->wp->window, ictx->input_buf);
 	options_set_number(ictx->wp->window->options, "automatic-rename", 0);
-
 	server_status_window(ictx->wp->window);
 }