diff --git a/content/base/src/nsNodeIterator.cpp b/content/base/src/nsNodeIterator.cpp
index 5ed96bdda1a..bcfb60f7c00 100644
--- a/content/base/src/nsNodeIterator.cpp
+++ b/content/base/src/nsNodeIterator.cpp
@@ -94,9 +94,14 @@ PRBool nsNodeIterator::NodePointer::MoveToPrevious(nsINode *aRoot)
     return PR_TRUE;
 }
 
-void nsNodeIterator::NodePointer::AdjustAfterInsertion(nsINode *aContainer, PRInt32 aIndexInContainer)
+void nsNodeIterator::NodePointer::AdjustAfterInsertion(nsINode *aRoot,
+                                                       nsINode *aContainer,
+                                                       PRInt32 aIndexInContainer)
 {
-    if (!mNode)
+    // If mNode is null or the root there is nothing to do. This also prevents
+    // valgrind from complaining about consuming uninitialized memory for
+    // mNodeParent and mIndexInParent
+    if (!mNode || mNode == aRoot)
         return;
 
     // check if earlier sibling was added
@@ -104,21 +109,19 @@ void nsNodeIterator::NodePointer::AdjustAfterInsertion(nsINode *aContainer, PRIn
         mIndexInParent++;
 }
 
-void nsNodeIterator::NodePointer::AdjustAfterRemoval(nsINode* aRoot,
+void nsNodeIterator::NodePointer::AdjustAfterRemoval(nsINode *aRoot,
                                                      nsINode *aContainer,
                                                      nsIContent *aChild,
                                                      PRInt32 aIndexInContainer)
 {
-    if (!mNode)
+    // If mNode is null or the root there is nothing to do. This also prevents
+    // valgrind from complaining about consuming uninitialized memory for
+    // mNodeParent and mIndexInParent
+    if (!mNode || mNode == aRoot)
         return;
 
     // Check if earlier sibling was removed.
-    // The mNode != aRoot check isn't strictly needed because if mNode is the
-    // root, we'll never use mNodeParent or mIndexInParent. However without the
-    // check valgrind will (rightly) complain about reading uninitialized
-    // memory.
-    if (mNode != aRoot &&
-        aContainer == mNodeParent && aIndexInContainer < mIndexInParent) {
+    if (aContainer == mNodeParent && aIndexInContainer < mIndexInParent) {
         --mIndexInParent;
         return;
     }
@@ -368,15 +371,15 @@ NS_IMETHODIMP nsNodeIterator::GetPointerBeforeReferenceNode(PRBool *aBeforeNode)
  * nsIMutationObserver interface
  */
 
-void nsNodeIterator::ContentInserted(nsIDocument* aDocument,
-                                     nsIContent* aContainer,
-                                     nsIContent* aChild,
+void nsNodeIterator::ContentInserted(nsIDocument *aDocument,
+                                     nsIContent *aContainer,
+                                     nsIContent *aChild,
                                      PRInt32 aIndexInContainer)
 {
     nsINode *container = NODE_FROM(aContainer, aDocument);
 
-    mPointer.AdjustAfterInsertion(container, aIndexInContainer);
-    mWorkingPointer.AdjustAfterInsertion(container, aIndexInContainer);
+    mPointer.AdjustAfterInsertion(mRoot, container, aIndexInContainer);
+    mWorkingPointer.AdjustAfterInsertion(mRoot, container, aIndexInContainer);
 }
 
 
diff --git a/content/base/src/nsNodeIterator.h b/content/base/src/nsNodeIterator.h
index a5661048c3e..14b654af21b 100644
--- a/content/base/src/nsNodeIterator.h
+++ b/content/base/src/nsNodeIterator.h
@@ -83,9 +83,9 @@ private:
         PRBool MoveForward(nsINode *aRoot, nsINode *aParent, PRInt32 aChildNum);
         void MoveBackward(nsINode *aParent, PRInt32 aChildNum);
 
-        void AdjustAfterInsertion(nsINode *aContainer, PRInt32 aIndexInContainer);
+        void AdjustAfterInsertion(nsINode *aRoot, nsINode *aContainer, PRInt32 aIndexInContainer);
         void AdjustAfterRemoval(nsINode *aRoot, nsINode *aContainer, nsIContent *aChild, PRInt32 aIndexInContainer);
-        
+
         void Clear() { mNode = nsnull; }
 
         nsINode *mNode;