Fixed bug 211990: Restore Defaults button does not work properly for
Quick Diff Preferences
diff --git a/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/text/QuickDiffConfigurationBlock.java b/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/text/QuickDiffConfigurationBlock.java
index bb2e540..a8944b8 100644
--- a/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/text/QuickDiffConfigurationBlock.java
+++ b/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/text/QuickDiffConfigurationBlock.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2009 IBM Corporation and others.
+ * Copyright (c) 2000, 2012 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -418,6 +418,7 @@
 	public void performDefaults() {
 		initializeFields();
 		updateProviderList();
+		updateEnablement();
 	}
 
 	private void updateQuickDiffControls() {