[282684] NPE in org.eclipse.wst.xml.core.internal.document.AttrImpl.setNodeValue if nodeValue is null

bundles/org.eclipse.wst.xml.core/src/org/eclipse/wst/xml/core/internal/document/AttrImpl.java

diff --git a/bundles/org.eclipse.wst.xml.core/src/org/eclipse/wst/xml/core/internal/document/AttrImpl.java b/bundles/org.eclipse.wst.xml.core/src/org/eclipse/wst/xml/core/internal/document/AttrImpl.java
index e82da26..fcb80b6 100644
--- a/bundles/org.eclipse.wst.xml.core/src/org/eclipse/wst/xml/core/internal/document/AttrImpl.java
+++ b/bundles/org.eclipse.wst.xml.core/src/org/eclipse/wst/xml/core/internal/document/AttrImpl.java
@@ -750,7 +750,7 @@
 		if (this.ownerElement != null && !this.ownerElement.isDataEditable()) {
 			throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, new String());
 		}
-		this.fValueSource = source.toCharArray();
+		this.fValueSource = (source != null) ? source.toCharArray() : null;
 
 		notifyValueChanged();
 	}