If display-time is set to 0, show status messages until a key is pressed;

OK nicm@

options-table.c

@@ -198,7 +198,7 @@ const struct options_table_entry options_table[] = {
 	{ .name = "display-time",
 	  .type = OPTIONS_TABLE_NUMBER,
 	  .scope = OPTIONS_TABLE_SESSION,
-	  .minimum = 1,
+	  .minimum = 0,
 	  .maximum = INT_MAX,
 	  .default_num = 750
 	},

status.c

@@ -574,6 +574,7 @@ status_message_set(struct client *c, const char *fmt, ...)
 	}
 
 	delay = options_get_number(c->session->options, "display-time");
+	if (delay > 0) {
 		tv.tv_sec = delay / 1000;
 		tv.tv_usec = (delay % 1000) * 1000L;
 
@@ -581,6 +582,7 @@ status_message_set(struct client *c, const char *fmt, ...)
 			evtimer_del(&c->message_timer);
 		evtimer_set(&c->message_timer, status_message_callback, c);
 		evtimer_add(&c->message_timer, &tv);
+	}
 
 	c->tty.flags |= (TTY_NOCURSOR|TTY_FREEZE);
 	c->flags |= CLIENT_STATUS;

tmux.1

@@ -2557,6 +2557,7 @@ command appear.
 .It Ic display-time Ar time
 Set the amount of time for which status line messages and other on-screen
 indicators are displayed.
+If set to 0, messages and indicators are displayed until a key is pressed.
 .Ar time
 is in milliseconds.
 .It Ic history-limit Ar lines