===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/control.c,v
retrieving revision 1.45
retrieving revision 1.46
diff -u -r1.45 -r1.46
--- src/usr.bin/tmux/control.c	2020/09/18 11:20:59	1.45
+++ src/usr.bin/tmux/control.c	2021/08/17 20:17:21	1.46
@@ -1,4 +1,4 @@
-/* $OpenBSD: control.c,v 1.45 2020/09/18 11:20:59 nicm Exp $ */
+/* $OpenBSD: control.c,v 1.46 2021/08/17 20:17:21 nicm Exp $ */
 
 /*
  * Copyright (c) 2012 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -665,7 +665,7 @@
 	uint64_t		 age, t = get_timer();
 
 	wp = control_window_pane(c, cp->pane);
-	if (wp == NULL) {
+	if (wp == NULL || wp->fd == -1) {
 		TAILQ_FOREACH_SAFE(cb, &cp->blocks, entry, cb1) {
 			TAILQ_REMOVE(&cp->blocks, cb, entry);
 			control_free_block(cs, cb);
@@ -865,7 +865,7 @@
 	struct control_sub_pane	*csp, find;
 
 	wp = window_pane_find_by_id(csub->id);
-	if (wp == NULL)
+	if (wp == NULL || wp->fd == -1)
 		return;
 	w = wp->window;