Fixing bug 135278. Stop don't use Substring() on a null poiter, Substring() asserts if given a null pointer. r=dbaron@fas.harvard.edu, sr=jaggernaut@netscape.com

content/base/src/nsGenericDOMDataNode.cpp

@@ -434,7 +434,12 @@ nsGenericDOMDataNode::GetData(nsAString& aData)
     // terminated strings.
 
     const char *data = mText.Get1b();
-    CopyASCIItoUCS2(Substring(data, data + mText.GetLength()), aData);
+
+    if (data) {
+      CopyASCIItoUCS2(Substring(data, data + mText.GetLength()), aData);
+    } else {
+      aData.Truncate();
+    }
   }
 
   return NS_OK;