Index: mozilla/content/events/src/nsEventStateManager.cpp
===================================================================
RCS file: /cvsroot/mozilla/content/events/src/nsEventStateManager.cpp,v
retrieving revision 1.647
diff -pU10 -r1.647 mozilla/content/events/src/nsEventStateManager.cpp
--- mozilla/content/events/src/nsEventStateManager.cpp
+++ mozilla/content/events/src/nsEventStateManager.cpp
@@ -407,40 +407,39 @@ SetFrameExternalReference(nsIFrame* aFra
 
 NS_IMETHODIMP
 nsEventStateManager::PreHandleEvent(nsPresContext* aPresContext,
                                     nsEvent *aEvent,
                                     nsIFrame* aTargetFrame,
                                     nsEventStatus* aStatus,
                                     nsIView* aView)
 {
   NS_ENSURE_ARG_POINTER(aStatus);
   NS_ENSURE_ARG(aPresContext);
+  if (!aEvent) {
+    NS_ERROR("aEvent is null.  This should never happen.");
+    return NS_ERROR_NULL_POINTER;
+  }
 
   mCurrentTarget = aTargetFrame;
   mCurrentTargetContent = nsnull;
 
   // Focus events don't necessarily need a frame.
   if (NS_EVENT_NEEDS_FRAME(aEvent)) {
     NS_ASSERTION(mCurrentTarget, "mCurrentTarget is null.  this should not happen.  see bug #13007");
     if (!mCurrentTarget) return NS_ERROR_NULL_POINTER;
   }
 
   if (mCurrentTarget)
     SetFrameExternalReference(mCurrentTarget);
 
   *aStatus = nsEventStatus_eIgnore;
 
-  if (!aEvent) {
-    NS_ERROR("aEvent is null.  This should never happen.");
-    return NS_ERROR_NULL_POINTER;
-  }
-
   switch (aEvent->message) {
   case NS_MOUSE_LEFT_BUTTON_DOWN:
 #ifndef XP_OS2
     BeginTrackingDragGesture ( aPresContext, (nsMouseEvent*)aEvent, aTargetFrame );
 #endif
     mLClickCount = ((nsMouseEvent*)aEvent)->clickCount;
     SetClickCount(aPresContext, (nsMouseEvent*)aEvent, aStatus);
     mNormalLMouseEventInProcess = PR_TRUE;
     break;
   case NS_MOUSE_MIDDLE_BUTTON_DOWN: