patch 8.2.2999: balloon sometimes does not hide with GTK 3

Problem:    Balloon sometimes does not hide with GTK 3.
Solution:   Also listen to GDK_LEAVE_NOTIFY. (Johannes Stezenbach)

src/gui_beval.c

@@ -253,6 +253,9 @@ addEventHandler(GtkWidget *target, BalloonEval *beval)
     if (gtk_socket_id == 0 && gui.mainwin != NULL
 	    && gtk_widget_is_ancestor(target, gui.mainwin))
     {
+	gtk_widget_add_events(gui.mainwin,
+			      GDK_LEAVE_NOTIFY_MASK);
+
 	g_signal_connect(G_OBJECT(gui.mainwin), "event",
 			 G_CALLBACK(mainwin_event_cb),
 			 beval);
@@ -360,6 +363,12 @@ mainwin_event_cb(GtkWidget *widget UNUSED, GdkEvent *event, gpointer data)
 	case GDK_KEY_RELEASE:
 	    key_event(beval, event->key.keyval, FALSE);
 	    break;
+	case GDK_LEAVE_NOTIFY:
+	    // Ignore LeaveNotify events that are not "normal".
+	    // Apparently we also get it when somebody else grabs focus.
+	    if (event->crossing.mode == GDK_CROSSING_NORMAL)
+		cancelBalloon(beval);
+	    break;
 	default:
 	    break;
     }

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2999,
 /**/
     2998,
 /**/