From 17efdd55c011a2b40bea81654b11f7fb14174e1c Mon Sep 17 00:00:00 2001
From: "jfrancis%netscape.com" <jfrancis%netscape.com>
Date: Mon, 8 Mar 1999 01:20:02 +0000
Subject: [PATCH] bug fixes + changing broken "dont_QueryInterface" additions
 to "do_QueryInterface"

---
 content/base/src/nsContentIterator.cpp | 45 ++++++++++++++------------
 content/base/src/nsRange.cpp           | 43 +++++++++++-------------
 layout/base/src/nsContentIterator.cpp  | 45 ++++++++++++++------------
 layout/base/src/nsRange.cpp            | 43 +++++++++++-------------
 4 files changed, 86 insertions(+), 90 deletions(-)

diff --git a/content/base/src/nsContentIterator.cpp b/content/base/src/nsContentIterator.cpp
index ff28ee787aaf..30eeb5b9b842 100644
--- a/content/base/src/nsContentIterator.cpp
+++ b/content/base/src/nsContentIterator.cpp
@@ -173,7 +173,7 @@ nsresult nsContentIterator::Init(nsIContent* aRoot)
   if (!aRoot) 
     return NS_ERROR_NULL_POINTER; 
 
-  nsCOMPtr<nsIContent> root( dont_QueryInterface(aRoot) );
+  nsCOMPtr<nsIContent> root( do_QueryInterface(aRoot) );
   mFirst = GetDeepFirstChild(root); 
   mLast = root;
   mCommonParent = root;
@@ -349,6 +349,7 @@ nsresult nsContentIterator::GetNextSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   
   if (!NS_SUCCEEDED(aNode->GetParent(*getter_AddRefs(parent))))
     return NS_ERROR_FAILURE;
+
   if (!NS_SUCCEEDED(parent->IndexOf(aNode, indx)))
     return NS_ERROR_FAILURE;
 
@@ -358,7 +359,7 @@ nsresult nsContentIterator::GetNextSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   }
   else if (parent != mCommonParent)
   {
-    GetNextSibling(parent, aSibling);
+    return GetNextSibling(parent, aSibling);
   }
   else
   {
@@ -382,6 +383,7 @@ nsresult nsContentIterator::GetPrevSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   
   if (!NS_SUCCEEDED(aNode->GetParent(*getter_AddRefs(parent))))
     return NS_ERROR_FAILURE;
+
   if (!NS_SUCCEEDED(parent->IndexOf(aNode, indx)))
     return NS_ERROR_FAILURE;
 
@@ -391,7 +393,7 @@ nsresult nsContentIterator::GetPrevSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   }
   else if (parent != mCommonParent)
   {
-    GetPrevSibling(parent, aSibling);
+    return GetPrevSibling(parent, aSibling);
   }
   else
   {
@@ -612,7 +614,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   if (!aRange) 
     return NS_ERROR_NULL_POINTER; 
 
-  mRange = dont_QueryInterface(aRange);
+  mRange = do_QueryInterface(aRange);
   
   // get the start node and offset, convert to nsIContent
   nsCOMPtr<nsIDOMNode> commonParent;
@@ -621,7 +623,8 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   nsCOMPtr<nsIContent> cStartP;
   nsCOMPtr<nsIContent> cEndP;
   nsCOMPtr<nsIContent> cN;
-  nsCOMPtr<nsIContent> candidate;
+  nsCOMPtr<nsIContent> firstCandidate;
+  nsCOMPtr<nsIContent> lastCandidate;
 
   // get common content parent
   if (!NS_SUCCEEDED(aRange->GetCommonParent(getter_AddRefs(commonParent))) || !commonParent)
@@ -646,7 +649,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   PRInt32 numChildren;
   cStartP->ChildCount(numChildren);
   
-  if (numChildren) // no children, must be a text node
+  if (!numChildren) // no children, must be a text node
   {
     cN = cStartP; 
   }
@@ -659,28 +662,28 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
     }
     else
     {
-      candidate = cChild;
+      firstCandidate = cChild;
     }
   }
   
-  if (!candidate)
+  if (!firstCandidate)
   {
-    // then candidate is next node after cN
-    if (!NS_SUCCEEDED(GetNextSibling(cN,  &candidate)))
+    // then firstCandidate is next node after cN
+    if (!NS_SUCCEEDED(GetNextSibling(cN,  &firstCandidate)))
     {
       MakeEmpty();
       return NS_OK;
     }
   }
   
-  candidate = GetDeepFirstChild(candidate);
+  firstCandidate = GetDeepFirstChild(firstCandidate);
   
   // confirm that this first possible contained node
   // is indeed contained.  Else we have a range that
   // does not fully contain any node.
   
   PRBool nodeBefore, nodeAfter;
-  if (!NS_SUCCEEDED(CompareNodeToRange(candidate, aRange, &nodeBefore, &nodeAfter)))
+  if (!NS_SUCCEEDED(CompareNodeToRange(firstCandidate, aRange, &nodeBefore, &nodeAfter)))
     return NS_ERROR_FAILURE;
   if (nodeBefore || nodeAfter)
   {
@@ -691,7 +694,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   // cool, we have the first node in the range.  Now we walk
   // up it's ancestors to find the most senior that is still
   // in the range.  That's the real first node.
-  if (!NS_SUCCEEDED(GetTopAncestorInRange(candidate, &mFirst)))
+  if (!NS_SUCCEEDED(GetTopAncestorInRange(firstCandidate, &mFirst)))
     return NS_ERROR_FAILURE;
   
   
@@ -706,7 +709,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   {
     cEndP->ChildCount(numChildren);
   
-    if (numChildren) // no children, must be a text node
+    if (!numChildren) // no children, must be a text node
     {
       cN = cEndP; 
     }
@@ -720,28 +723,28 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
       }
       else
       {
-        candidate = cChild;
+        lastCandidate = cChild;
       }
     }
   }
   
-  if (!candidate)
+  if (!lastCandidate)
   {
-    // then candidate is prev node before cN
-    if (!NS_SUCCEEDED(GetPrevSibling(cN, &candidate)))
+    // then lastCandidate is prev node before cN
+    if (!NS_SUCCEEDED(GetPrevSibling(cN, &lastCandidate)))
     {
       MakeEmpty();
       return NS_OK;
     }
   }
   
-  candidate = GetDeepLastChild(candidate);
+  lastCandidate = GetDeepLastChild(lastCandidate);
   
   // confirm that this first possible contained node
   // is indeed contained.  Else we have a range that
   // does not fully contain any node.
   
-  if (!NS_SUCCEEDED(CompareNodeToRange(candidate, aRange, &nodeBefore, &nodeAfter)))
+  if (!NS_SUCCEEDED(CompareNodeToRange(lastCandidate, aRange, &nodeBefore, &nodeAfter)))
     return NS_ERROR_FAILURE;
   if (nodeBefore || nodeAfter)
   {
@@ -752,7 +755,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   // cool, we have the last node in the range.  Now we walk
   // up it's ancestors to find the most senior that is still
   // in the range.  That's the real first node.
-  if (!NS_SUCCEEDED(GetTopAncestorInRange(candidate, &mLast)))
+  if (!NS_SUCCEEDED(GetTopAncestorInRange(lastCandidate, &mLast)))
     return NS_ERROR_FAILURE;
   
   mCurNode = mFirst;
diff --git a/content/base/src/nsRange.cpp b/content/base/src/nsRange.cpp
index 53220309d758..183867298c7a 100644
--- a/content/base/src/nsRange.cpp
+++ b/content/base/src/nsRange.cpp
@@ -648,17 +648,12 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
   
   // no null nodes please
   if (!aNode1 || !aNode2) 
-    return nsCOMPtr<nsIDOMNode>();  // moral equiv or nsnull
+    return nsCOMPtr<nsIDOMNode>();  // moral equiv of nsnull
   
   // shortcut for common case - both nodes are the same
   if (aNode1 == aNode2)
   {
-    // should be able to remove this error check later
-    nsresult res = aNode1->GetParentNode(getter_AddRefs(theParent));
-    if (!NS_SUCCEEDED(res)) 
-      return nsCOMPtr<nsIDOMNode>();  // moral equiv or nsnull
-
-    return theParent;
+    return aNode1;
   }
 
   // otherwise traverse the tree for the common ancestor
@@ -673,7 +668,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // get ancestors of each node
@@ -686,7 +681,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // sanity test (for now) - the end of each array
@@ -696,7 +691,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // back through the ancestors, starting from the root, until
@@ -881,7 +876,7 @@ nsresult nsRange::SetStart(nsIDOMNode* aParent, PRInt32 aOffset)
   
   if (!aParent) return NS_ERROR_NULL_POINTER;
   
-  nsCOMPtr<nsIDOMNode>theParent( dont_QueryInterface(aParent) );
+  nsCOMPtr<nsIDOMNode>theParent( do_QueryInterface(aParent) );
     
   // must be in same document as endpoint, else 
   // endpoint is collapsed to new start.
@@ -902,7 +897,7 @@ nsresult nsRange::SetStart(nsIDOMNode* aParent, PRInt32 aOffset)
 
 nsresult nsRange::SetStartBefore(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling);
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -911,7 +906,7 @@ nsresult nsRange::SetStartBefore(nsIDOMNode* aSibling)
 
 nsresult nsRange::SetStartAfter(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling) + 1;
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -924,7 +919,7 @@ nsresult nsRange::SetEnd(nsIDOMNode* aParent, PRInt32 aOffset)
   
   if (!aParent) return NS_ERROR_NULL_POINTER;
 
-  nsCOMPtr<nsIDOMNode>theParent( dont_QueryInterface(aParent) );
+  nsCOMPtr<nsIDOMNode>theParent( do_QueryInterface(aParent) );
   
   // must be in same document as startpoint, else 
   // endpoint is collapsed to new end.
@@ -945,7 +940,7 @@ nsresult nsRange::SetEnd(nsIDOMNode* aParent, PRInt32 aOffset)
 
 nsresult nsRange::SetEndBefore(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling);
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -954,7 +949,7 @@ nsresult nsRange::SetEndBefore(nsIDOMNode* aSibling)
 
 nsresult nsRange::SetEndAfter(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling) + 1;
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -985,7 +980,7 @@ nsresult nsRange::Unposition()
 nsresult nsRange::SelectNode(nsIDOMNode* aN)
 {
   nsCOMPtr<nsIDOMNode> parent;
-  nsCOMPtr<nsIDOMNode> theNode( dont_QueryInterface(aN) );
+  nsCOMPtr<nsIDOMNode> theNode( do_QueryInterface(aN) );
   
   nsresult res = aN->GetParentNode(getter_AddRefs(parent));
   if (!NS_SUCCEEDED(res))
@@ -997,7 +992,7 @@ nsresult nsRange::SelectNode(nsIDOMNode* aN)
 
 nsresult nsRange::SelectNodeContents(nsIDOMNode* aN)
 {
-  nsCOMPtr<nsIDOMNode> theNode( dont_QueryInterface(aN) );
+  nsCOMPtr<nsIDOMNode> theNode( do_QueryInterface(aN) );
   nsCOMPtr<nsIDOMNodeList> aChildNodes;
   
   nsresult res = aN->GetChildNodes(getter_AddRefs(aChildNodes));
@@ -1503,7 +1498,7 @@ nsresult nsRange::OwnerChildInserted(nsIContent* aParentNode, PRInt32 aOffset)
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aParentNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
   // quick return if no range list
   nsVoidArray *theRangeList;
   parent->GetRangeList(theRangeList);
@@ -1548,8 +1543,8 @@ nsresult nsRange::OwnerChildRemoved(nsIContent* aParentNode, PRInt32 aOffset, ns
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aParentNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
-  nsCOMPtr<nsIContent> removed( dont_QueryInterface(aRemovedNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> removed( do_QueryInterface(aRemovedNode) );
   // quick return if no range list
   nsVoidArray *theRangeList;
   parent->GetRangeList(theRangeList);
@@ -1606,8 +1601,8 @@ nsresult nsRange::OwnerChildReplaced(nsIContent* aParentNode, PRInt32 aOffset, n
   // but we do need to pop out any range endpoints inside the subtree
   // rooted by aReplacedNode.
   
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
-  nsCOMPtr<nsIContent> replaced( dont_QueryInterface(aReplacedNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> replaced( do_QueryInterface(aReplacedNode) );
   nsCOMPtr<nsIDOMNode> parentDomNode; 
   nsresult res;
   
@@ -1626,7 +1621,7 @@ nsresult nsRange::TextOwnerChanged(nsIContent* aTextNode, PRInt32 aStartChanged,
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aTextNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> textNode( dont_QueryInterface(aTextNode) );
+  nsCOMPtr<nsIContent> textNode( do_QueryInterface(aTextNode) );
   nsVoidArray *theRangeList;
   aTextNode->GetRangeList(theRangeList);
   // the caller already checked to see if there was a range list
diff --git a/layout/base/src/nsContentIterator.cpp b/layout/base/src/nsContentIterator.cpp
index ff28ee787aaf..30eeb5b9b842 100644
--- a/layout/base/src/nsContentIterator.cpp
+++ b/layout/base/src/nsContentIterator.cpp
@@ -173,7 +173,7 @@ nsresult nsContentIterator::Init(nsIContent* aRoot)
   if (!aRoot) 
     return NS_ERROR_NULL_POINTER; 
 
-  nsCOMPtr<nsIContent> root( dont_QueryInterface(aRoot) );
+  nsCOMPtr<nsIContent> root( do_QueryInterface(aRoot) );
   mFirst = GetDeepFirstChild(root); 
   mLast = root;
   mCommonParent = root;
@@ -349,6 +349,7 @@ nsresult nsContentIterator::GetNextSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   
   if (!NS_SUCCEEDED(aNode->GetParent(*getter_AddRefs(parent))))
     return NS_ERROR_FAILURE;
+
   if (!NS_SUCCEEDED(parent->IndexOf(aNode, indx)))
     return NS_ERROR_FAILURE;
 
@@ -358,7 +359,7 @@ nsresult nsContentIterator::GetNextSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   }
   else if (parent != mCommonParent)
   {
-    GetNextSibling(parent, aSibling);
+    return GetNextSibling(parent, aSibling);
   }
   else
   {
@@ -382,6 +383,7 @@ nsresult nsContentIterator::GetPrevSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   
   if (!NS_SUCCEEDED(aNode->GetParent(*getter_AddRefs(parent))))
     return NS_ERROR_FAILURE;
+
   if (!NS_SUCCEEDED(parent->IndexOf(aNode, indx)))
     return NS_ERROR_FAILURE;
 
@@ -391,7 +393,7 @@ nsresult nsContentIterator::GetPrevSibling(nsCOMPtr<nsIContent> aNode, nsCOMPtr<
   }
   else if (parent != mCommonParent)
   {
-    GetPrevSibling(parent, aSibling);
+    return GetPrevSibling(parent, aSibling);
   }
   else
   {
@@ -612,7 +614,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   if (!aRange) 
     return NS_ERROR_NULL_POINTER; 
 
-  mRange = dont_QueryInterface(aRange);
+  mRange = do_QueryInterface(aRange);
   
   // get the start node and offset, convert to nsIContent
   nsCOMPtr<nsIDOMNode> commonParent;
@@ -621,7 +623,8 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   nsCOMPtr<nsIContent> cStartP;
   nsCOMPtr<nsIContent> cEndP;
   nsCOMPtr<nsIContent> cN;
-  nsCOMPtr<nsIContent> candidate;
+  nsCOMPtr<nsIContent> firstCandidate;
+  nsCOMPtr<nsIContent> lastCandidate;
 
   // get common content parent
   if (!NS_SUCCEEDED(aRange->GetCommonParent(getter_AddRefs(commonParent))) || !commonParent)
@@ -646,7 +649,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   PRInt32 numChildren;
   cStartP->ChildCount(numChildren);
   
-  if (numChildren) // no children, must be a text node
+  if (!numChildren) // no children, must be a text node
   {
     cN = cStartP; 
   }
@@ -659,28 +662,28 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
     }
     else
     {
-      candidate = cChild;
+      firstCandidate = cChild;
     }
   }
   
-  if (!candidate)
+  if (!firstCandidate)
   {
-    // then candidate is next node after cN
-    if (!NS_SUCCEEDED(GetNextSibling(cN,  &candidate)))
+    // then firstCandidate is next node after cN
+    if (!NS_SUCCEEDED(GetNextSibling(cN,  &firstCandidate)))
     {
       MakeEmpty();
       return NS_OK;
     }
   }
   
-  candidate = GetDeepFirstChild(candidate);
+  firstCandidate = GetDeepFirstChild(firstCandidate);
   
   // confirm that this first possible contained node
   // is indeed contained.  Else we have a range that
   // does not fully contain any node.
   
   PRBool nodeBefore, nodeAfter;
-  if (!NS_SUCCEEDED(CompareNodeToRange(candidate, aRange, &nodeBefore, &nodeAfter)))
+  if (!NS_SUCCEEDED(CompareNodeToRange(firstCandidate, aRange, &nodeBefore, &nodeAfter)))
     return NS_ERROR_FAILURE;
   if (nodeBefore || nodeAfter)
   {
@@ -691,7 +694,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   // cool, we have the first node in the range.  Now we walk
   // up it's ancestors to find the most senior that is still
   // in the range.  That's the real first node.
-  if (!NS_SUCCEEDED(GetTopAncestorInRange(candidate, &mFirst)))
+  if (!NS_SUCCEEDED(GetTopAncestorInRange(firstCandidate, &mFirst)))
     return NS_ERROR_FAILURE;
   
   
@@ -706,7 +709,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   {
     cEndP->ChildCount(numChildren);
   
-    if (numChildren) // no children, must be a text node
+    if (!numChildren) // no children, must be a text node
     {
       cN = cEndP; 
     }
@@ -720,28 +723,28 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
       }
       else
       {
-        candidate = cChild;
+        lastCandidate = cChild;
       }
     }
   }
   
-  if (!candidate)
+  if (!lastCandidate)
   {
-    // then candidate is prev node before cN
-    if (!NS_SUCCEEDED(GetPrevSibling(cN, &candidate)))
+    // then lastCandidate is prev node before cN
+    if (!NS_SUCCEEDED(GetPrevSibling(cN, &lastCandidate)))
     {
       MakeEmpty();
       return NS_OK;
     }
   }
   
-  candidate = GetDeepLastChild(candidate);
+  lastCandidate = GetDeepLastChild(lastCandidate);
   
   // confirm that this first possible contained node
   // is indeed contained.  Else we have a range that
   // does not fully contain any node.
   
-  if (!NS_SUCCEEDED(CompareNodeToRange(candidate, aRange, &nodeBefore, &nodeAfter)))
+  if (!NS_SUCCEEDED(CompareNodeToRange(lastCandidate, aRange, &nodeBefore, &nodeAfter)))
     return NS_ERROR_FAILURE;
   if (nodeBefore || nodeAfter)
   {
@@ -752,7 +755,7 @@ nsresult nsContentSubtreeIterator::Init(nsIDOMRange* aRange)
   // cool, we have the last node in the range.  Now we walk
   // up it's ancestors to find the most senior that is still
   // in the range.  That's the real first node.
-  if (!NS_SUCCEEDED(GetTopAncestorInRange(candidate, &mLast)))
+  if (!NS_SUCCEEDED(GetTopAncestorInRange(lastCandidate, &mLast)))
     return NS_ERROR_FAILURE;
   
   mCurNode = mFirst;
diff --git a/layout/base/src/nsRange.cpp b/layout/base/src/nsRange.cpp
index 53220309d758..183867298c7a 100644
--- a/layout/base/src/nsRange.cpp
+++ b/layout/base/src/nsRange.cpp
@@ -648,17 +648,12 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
   
   // no null nodes please
   if (!aNode1 || !aNode2) 
-    return nsCOMPtr<nsIDOMNode>();  // moral equiv or nsnull
+    return nsCOMPtr<nsIDOMNode>();  // moral equiv of nsnull
   
   // shortcut for common case - both nodes are the same
   if (aNode1 == aNode2)
   {
-    // should be able to remove this error check later
-    nsresult res = aNode1->GetParentNode(getter_AddRefs(theParent));
-    if (!NS_SUCCEEDED(res)) 
-      return nsCOMPtr<nsIDOMNode>();  // moral equiv or nsnull
-
-    return theParent;
+    return aNode1;
   }
 
   // otherwise traverse the tree for the common ancestor
@@ -673,7 +668,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // get ancestors of each node
@@ -686,7 +681,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // sanity test (for now) - the end of each array
@@ -696,7 +691,7 @@ nsCOMPtr<nsIDOMNode> nsRange::CommonParent(nsCOMPtr<nsIDOMNode> aNode1, nsCOMPtr
     NS_NOTREACHED("nsRange::CommonParent");
     delete array1;
     delete array2;
-    return nsCOMPtr<nsIDOMNode>();
+    return nsCOMPtr<nsIDOMNode>(); // moral equiv of nsnull
   }
   
   // back through the ancestors, starting from the root, until
@@ -881,7 +876,7 @@ nsresult nsRange::SetStart(nsIDOMNode* aParent, PRInt32 aOffset)
   
   if (!aParent) return NS_ERROR_NULL_POINTER;
   
-  nsCOMPtr<nsIDOMNode>theParent( dont_QueryInterface(aParent) );
+  nsCOMPtr<nsIDOMNode>theParent( do_QueryInterface(aParent) );
     
   // must be in same document as endpoint, else 
   // endpoint is collapsed to new start.
@@ -902,7 +897,7 @@ nsresult nsRange::SetStart(nsIDOMNode* aParent, PRInt32 aOffset)
 
 nsresult nsRange::SetStartBefore(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling);
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -911,7 +906,7 @@ nsresult nsRange::SetStartBefore(nsIDOMNode* aSibling)
 
 nsresult nsRange::SetStartAfter(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling) + 1;
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -924,7 +919,7 @@ nsresult nsRange::SetEnd(nsIDOMNode* aParent, PRInt32 aOffset)
   
   if (!aParent) return NS_ERROR_NULL_POINTER;
 
-  nsCOMPtr<nsIDOMNode>theParent( dont_QueryInterface(aParent) );
+  nsCOMPtr<nsIDOMNode>theParent( do_QueryInterface(aParent) );
   
   // must be in same document as startpoint, else 
   // endpoint is collapsed to new end.
@@ -945,7 +940,7 @@ nsresult nsRange::SetEnd(nsIDOMNode* aParent, PRInt32 aOffset)
 
 nsresult nsRange::SetEndBefore(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling);
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -954,7 +949,7 @@ nsresult nsRange::SetEndBefore(nsIDOMNode* aSibling)
 
 nsresult nsRange::SetEndAfter(nsIDOMNode* aSibling)
 {
-  nsCOMPtr<nsIDOMNode>theSibling( dont_QueryInterface(aSibling) );
+  nsCOMPtr<nsIDOMNode>theSibling( do_QueryInterface(aSibling) );
   PRInt32 indx = IndexOf(theSibling) + 1;
   nsIDOMNode *nParent;
   theSibling->GetParentNode(&nParent);
@@ -985,7 +980,7 @@ nsresult nsRange::Unposition()
 nsresult nsRange::SelectNode(nsIDOMNode* aN)
 {
   nsCOMPtr<nsIDOMNode> parent;
-  nsCOMPtr<nsIDOMNode> theNode( dont_QueryInterface(aN) );
+  nsCOMPtr<nsIDOMNode> theNode( do_QueryInterface(aN) );
   
   nsresult res = aN->GetParentNode(getter_AddRefs(parent));
   if (!NS_SUCCEEDED(res))
@@ -997,7 +992,7 @@ nsresult nsRange::SelectNode(nsIDOMNode* aN)
 
 nsresult nsRange::SelectNodeContents(nsIDOMNode* aN)
 {
-  nsCOMPtr<nsIDOMNode> theNode( dont_QueryInterface(aN) );
+  nsCOMPtr<nsIDOMNode> theNode( do_QueryInterface(aN) );
   nsCOMPtr<nsIDOMNodeList> aChildNodes;
   
   nsresult res = aN->GetChildNodes(getter_AddRefs(aChildNodes));
@@ -1503,7 +1498,7 @@ nsresult nsRange::OwnerChildInserted(nsIContent* aParentNode, PRInt32 aOffset)
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aParentNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
   // quick return if no range list
   nsVoidArray *theRangeList;
   parent->GetRangeList(theRangeList);
@@ -1548,8 +1543,8 @@ nsresult nsRange::OwnerChildRemoved(nsIContent* aParentNode, PRInt32 aOffset, ns
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aParentNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
-  nsCOMPtr<nsIContent> removed( dont_QueryInterface(aRemovedNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> removed( do_QueryInterface(aRemovedNode) );
   // quick return if no range list
   nsVoidArray *theRangeList;
   parent->GetRangeList(theRangeList);
@@ -1606,8 +1601,8 @@ nsresult nsRange::OwnerChildReplaced(nsIContent* aParentNode, PRInt32 aOffset, n
   // but we do need to pop out any range endpoints inside the subtree
   // rooted by aReplacedNode.
   
-  nsCOMPtr<nsIContent> parent( dont_QueryInterface(aParentNode) );
-  nsCOMPtr<nsIContent> replaced( dont_QueryInterface(aReplacedNode) );
+  nsCOMPtr<nsIContent> parent( do_QueryInterface(aParentNode) );
+  nsCOMPtr<nsIContent> replaced( do_QueryInterface(aReplacedNode) );
   nsCOMPtr<nsIDOMNode> parentDomNode; 
   nsresult res;
   
@@ -1626,7 +1621,7 @@ nsresult nsRange::TextOwnerChanged(nsIContent* aTextNode, PRInt32 aStartChanged,
   // sanity check - null nodes shouldn't have enclosed ranges
   if (!aTextNode) return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIContent> textNode( dont_QueryInterface(aTextNode) );
+  nsCOMPtr<nsIContent> textNode( do_QueryInterface(aTextNode) );
   nsVoidArray *theRangeList;
   aTextNode->GetRangeList(theRangeList);
   // the caller already checked to see if there was a range list