Product Version: NetBeans IDE 6.5 Beta (Build 200808070301)
Java: 1.6.0_10-rc; Java HotSpot(TM) Client VM 11.0-b13
System: Windows XP version 5.1 running on x86; Cp1252; en_GB (nb)
Userdir: D:\ide\65-beta\user6

Steps:
1. Open project under CVS control.
2. Modify the file and invoke "CVS | Diff" action.
3. In the right panel edit the file and push "Ctrl+S".

NPE is thrown.
 
SEVERE [global]
java.lang.NullPointerException
        at org.netbeans.modules.xml.schema.completion.util.CompletionUtil.canProvideCompletion(CompletionUtil.java:725)
        at
org.netbeans.modules.xml.schema.completion.SchemaBasedCompletionProvider.getAutoQueryTypes(SchemaBasedCompletionProvider.java:74)
        at org.netbeans.modules.editor.completion.CompletionImpl.insertUpdate(CompletionImpl.java:301)
        at
org.netbeans.lib.editor.util.swing.PriorityDocumentListenerList.insertUpdate(PriorityDocumentListenerList.java:70)
        at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:185)
        at org.netbeans.editor.BaseDocument.fireInsertUpdate(BaseDocument.java:1612)
        at org.netbeans.editor.BaseDocument.insertString(BaseDocument.java:770)
        at org.netbeans.editor.BaseKit$DefaultKeyTypedAction.insertString(BaseKit.java:1136)
        at org.netbeans.editor.BaseKit$DefaultKeyTypedAction$1.run(BaseKit.java:1103)
        at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:294)
        at org.netbeans.editor.BaseKit$DefaultKeyTypedAction.actionPerformed(BaseKit.java:1076)
        at org.netbeans.editor.ext.ExtKit$ExtDefaultKeyTypedAction.actionPerformed(ExtKit.java:1014)
        at org.netbeans.editor.BaseAction.actionPerformed(BaseAction.java:291)
        at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1636)