fix #21961, fix #24142 - apply patch by Taylor - fix ISE with F11 usage

git-svn-id: https://josm.openstreetmap.de/svn/trunk@19314 0c6e7542-c601-0410-84e7-c038aed88b3b

src/org/openstreetmap/josm/actions/FullscreenToggleAction.java

@@ -56,15 +56,25 @@ public void actionPerformed(ActionEvent e) {
         toggleSelectedState(e);
         Config.getPref().putBoolean("draw.fullscreen", isSelected());
         notifySelectedState();
-        setMode();
+        safeSetMode();
     }
 
     /**
      * To call if this action must be initially run at JOSM startup.
      */
     public void initial() {
         if (isSelected()) {
-            setMode();
+            safeSetMode();
+        }
+    }
+
+    protected void safeSetMode() {
+        try {
+            this.setMode();
+        } catch (Exception exception) {
+            // Something happened. Disable fullscreen.
+            Config.getPref().put("draw.fullscreen", null);
+            throw exception;
         }
     }