Bug 52346 [misc] Undo yields wrong code
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
import org.eclipse.jdt.ui.actions.GenerateActionGroup;
import org.eclipse.jdt.ui.actions.IJavaEditorActionDefinitionIds;
import org.eclipse.jdt.ui.actions.RefactorActionGroup;
import org.eclipse.jdt.internal.ui.IJavaHelpContextIds;
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.actions.AddBlockCommentAction;
import org.eclipse.jdt.internal.ui.actions.CompositeActionGroup;
import org.eclipse.jdt.internal.ui.actions.IndentAction;
import org.eclipse.jdt.internal.ui.actions.RemoveBlockCommentAction;
import org.eclipse.jdt.internal.ui.compare.LocalHistoryActionGroup;
import org.eclipse.jdt.internal.ui.text.ContentAssistPreference;
import org.eclipse.jdt.internal.ui.text.IJavaPartitions;
import org.eclipse.jdt.internal.ui.text.correction.JavaCorrectionAssistant;
import org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener;
import org.eclipse.jdt.internal.ui.text.java.SmartSemicolonAutoEditStrategy;
/**
 * Java specific text editor.
 */
public class CompilationUnitEditor extends JavaEditor implements IJavaReconcilingListener {
	/** 
	 * Text operation code for requesting correction assist to show correction
	 * proposals for the current position. 
	 */
	public static final int CORRECTIONASSIST_PROPOSALS= 50;
	/** 
	 * Text operation code for requesting common prefix completion. 
	 */
	public static final int CONTENTASSIST_COMPLETE_PREFIX= 60;
	
	interface ITextConverter {