Bug 52346 [misc] Undo yields wrong code
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
removeActionActivationCode("IndentOnTab"); 
					}
				}
				IContentAssistant c= asv.getContentAssistant();
				if (c instanceof ContentAssistant)
					ContentAssistPreference.changeConfiguration((ContentAssistant) c, getNewPreferenceStore(), event);
				if (CODE_FORMATTER_TAB_SIZE.equals(p)) {
					asv.updateIndentationPrefixes();
					if (fTabConverter != null)
						fTabConverter.setNumberOfSpacesPerTab(getTabSize());
				}
			}
				
		} finally {
			super.handlePreferenceStoreChanged(event);
		}
	}
	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor#createJavaSourceViewer(org.eclipse.swt.widgets.Composite, org.eclipse.jface.text.source.IVerticalRuler, org.eclipse.jface.text.source.IOverviewRuler, boolean, int)
	 */
	protected ISourceViewer createJavaSourceViewer(Composite parent, IVerticalRuler verticalRuler, IOverviewRuler overviewRuler, boolean isOverviewRulerVisible, int styles) {
		return new AdaptedSourceViewer(parent, verticalRuler, overviewRuler, isOverviewRulerVisible, styles);
	}
	
	/*
	 * @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#aboutToBeReconciled()
	 * @since 3.0
	 */
	public void aboutToBeReconciled() {