Bug 26035 Local history uses wrong character encoding
i set the windows->preferences->editors->TextFileEncoding to GBK it a Chinese charactor set.and then i wrote some Chinese in the println method just as System.out.println("2UEU"); after some modify,i replace this code back from Local History.a mistake appeared.it left a mess in the println sentence.the same mistake appear in WebSphere Application Developer 5.0
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/compare/JavaHistoryAction.java
}
	
	protected boolean isEnabled(ISelection selection) {
		IMember m= getEditionElement(selection);
		if (m == null)
			return false;
		IFile file= getFile(m);
		if (!isEnabled(file))
			return false;
		if (file != null && beingEdited(file))
			return getWorkingCopy(m) != null;
		return true;
	}
	
	/**
	 * Notifies this action delegate that the selection in the workbench has changed.
	 * <p>
	 * Implementers can use this opportunity to change the availability of the
	 * action or to modify other presentation properties.
	 * </p>
	 *
	 * @param action the action proxy that handles presentation portion of the action
	 * @param selection the current selection in the workbench
	 */
	public void selectionChanged(IAction action, ISelection selection) {
		fSelection= selection;
		action.setEnabled(isEnabled(selection));
	}
}