terminal: Only reset title if we put the window size there

When resizing the terminal, it shows the grid size in the titlebar.
We reset the title next time we get an enter event.  This patch makes
sure we only reset the title the first time we enter after a resize.

clients/terminal.c

@@ -465,6 +465,7 @@ struct terminal {
 	double average_width;
 	cairo_scaled_font_t *font_normal, *font_bold;
 	uint32_t hide_cursor_serial;
+	int size_in_title;
 
 	struct wl_data_source *selection;
 	uint32_t click_time;
@@ -850,6 +851,7 @@ resize_handler(struct widget *widget,
 		widget_set_size(terminal->widget, width, height);
 		if (asprintf(&p, "%s — [%dx%d]", terminal->title, columns, rows) > 0) {
 		    window_set_title(terminal->window, p);
+		    terminal->size_in_title = 1;
 		    free(p);
 		}
 	}
@@ -2740,7 +2742,10 @@ enter_handler(struct widget *widget,
 	struct terminal *terminal = data;
 
 	/* Reset title to get rid of resizing '[WxH]' in titlebar */
+	if (terminal->size_in_title) {
 		window_set_title(terminal->window, terminal->title);
+		terminal->size_in_title = 0;
+	}
 
 	return CURSOR_IBEAM;
 }