The Java console keeps showing up error reports due to being asked

to resize the puzzle to zero size. Ignore all such requests, in the
assumption that a more sensible resize will be along soon enough
(which does seem to happen, though I haven't debugged the NestedVM
front end hard enough to figure out why the bogus resizes happen in
the first place).

[originally from svn r8094]

PuzzleApplet.java

@@ -476,12 +476,14 @@ public class PuzzleApplet extends JApplet implements Runtime.CallJavaCB {
         }
 
         public void createBackBuffer(int w, int h, Color bg) {
+	    if (w > 0 && h > 0) {
 		backBuffer = new BufferedImage(w,h, BufferedImage.TYPE_3BYTE_BGR);
 		Graphics g = backBuffer.createGraphics();
 		g.setColor(bg);
 		g.fillRect(0, 0, w, h);
 		g.dispose();
 	    }
+        }
 
         protected void paintComponent(Graphics g) {
             g.drawImage(backBuffer, 0, 0, this);