Fixed bug where "backtrack to here" and "remove preceeding" where not disabled if the context menu popped up on the background

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@468 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/userinterface/simulator/GUISimulator.java

@@ -1870,8 +1870,8 @@ public class GUISimulator extends GUIPlugin implements MouseListener, ListSelect
 			}
 			if(e.isPopupTrigger() && (e.getSource() == pathTablePlaceHolder || e.getSource() == pathTable || e.getSource() == pathTable.getTableHeader() || e.getSource() == tableScroll))
 			{
-				backtrackToHere.setEnabled(!(e.getSource() == pathTable.getTableHeader() || e.getSource() == pathTable.getParent()));
-				removeToHere.setEnabled(!(e.getSource() == pathTable.getTableHeader() || e.getSource() == pathTable.getParent()));
+				backtrackToHere.setEnabled(!(e.getSource() == pathTable.getTableHeader() || e.getSource() == pathTablePlaceHolder|| e.getSource() == tableScroll));
+				removeToHere.setEnabled(!(e.getSource() == pathTable.getTableHeader() || e.getSource() == pathTablePlaceHolder|| e.getSource() == tableScroll));
 				
 				doEnables();