Bug 17699 Java Editor: Local Histroy menu entries are enabled for read-only files
F1 - make file read-only - open it - observe: context menu contains Local History actions. Only compare makes sense for read-only files
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/compare/JavaCompareWithEditionAction.java
private static final String BUNDLE_NAME= "org.eclipse.jdt.internal.ui.compare.CompareWithEditionAction"; 
	
	
	public JavaCompareWithEditionAction() {
	}	
	
	public void run(IAction action) {
		
		String errorTitle= CompareMessages.getString("ReplaceFromHistory.title"); 
		String errorMessage= CompareMessages.getString("ReplaceFromHistory.internalErrorMessage"); 
		
		Shell shell= JavaPlugin.getActiveWorkbenchShell();
		
		
		ISelection selection= getSelection();
		IMember input= getEditionElement(selection);
		if (input == null) {
			
			MessageDialog.openInformation(shell, errorTitle, errorMessage);
			return;
		}
		
		IFile file= getFile(input);