diff -r 2c585bb9560c -r 995162143ef4 src/Pure/GUI/swing_thread.scala
--- a/src/Pure/GUI/swing_thread.scala	Thu Feb 20 14:17:28 2014 +0100
+++ b/src/Pure/GUI/swing_thread.scala	Thu Feb 20 14:36:17 2014 +0100
@@ -7,6 +7,7 @@
 
 package isabelle
 
+
 import javax.swing.{SwingUtilities, Timer}
 import java.awt.event.{ActionListener, ActionEvent}