diff --git a/extensions/xforms/Makefile.in b/extensions/xforms/Makefile.in
index 11c14d444505..4ec22ca9dc7c 100644
--- a/extensions/xforms/Makefile.in
+++ b/extensions/xforms/Makefile.in
@@ -105,7 +105,6 @@ CPPSRCS		= \
 		nsXFormsAtoms.cpp \
 		nsXFormsModule.cpp \
 		nsXFormsMDGEngine.cpp \
-		nsXFormsMDGSet.cpp \
 		nsXFormsXPathAnalyzer.cpp \
 		nsXFormsXPathNode.cpp \
 		nsXFormsXPathParser.cpp \
diff --git a/extensions/xforms/nsIXFormsControl.idl b/extensions/xforms/nsIXFormsControl.idl
index e608759e3efa..9bc5ba2e2a8e 100644
--- a/extensions/xforms/nsIXFormsControl.idl
+++ b/extensions/xforms/nsIXFormsControl.idl
@@ -38,9 +38,13 @@
 
 #include "nsIXFormsContextControl.idl"
 
-interface nsIArray;
 interface nsIDOMNode;
 interface nsIDOMElement;
+%{C++
+  #include "nsCOMArray.h"
+%}
+
+[ptr] native nsCOMArrayPtr(nsCOMArray<nsIDOMNode>);
 
 /**
  * Interface implemented by all XForms form control classes.
@@ -79,11 +83,8 @@ interface nsIXFormsControl : nsIXFormsContextControl
    * nodes, all @owned attributes on /share nodes, and all /me nodes.
    *
    * @note The array MUST be sorted, pointer-order, ascending.
-   *
-   * @bug Should use nsCOMArray
-   *      @see https://bugzilla.mozilla.org/show_bug.cgi?id=278369
    */
-  readonly attribute nsIArray dependencies;
+  readonly attribute nsCOMArrayPtr dependencies;
 
   /**
    * Get the element that should receive events for the control.
diff --git a/extensions/xforms/nsXFormsControlStub.cpp b/extensions/xforms/nsXFormsControlStub.cpp
index a568c5fb2599..3ce89d8982fc 100644
--- a/extensions/xforms/nsXFormsControlStub.cpp
+++ b/extensions/xforms/nsXFormsControlStub.cpp
@@ -92,9 +92,10 @@ nsXFormsControlStub::GetBoundNode(nsIDOMNode **aBoundNode)
 }
 
 NS_IMETHODIMP
-nsXFormsControlStub::GetDependencies(nsIArray **aDependencies)
+nsXFormsControlStub::GetDependencies(nsCOMArray<nsIDOMNode> **aDependencies)
 {
-  NS_IF_ADDREF(*aDependencies = mDependencies);
+  if (aDependencies)
+    *aDependencies = &mDependencies;
   return NS_OK;  
 }
 
@@ -153,15 +154,9 @@ nsXFormsControlStub::ProcessNodeBinding(const nsString          &aBindingAttr,
                                         nsIDOMXPathResult      **aResult,
                                         nsIModelElementPrivate **aModel)
 {
-  nsresult rv;
+  mDependencies.Clear();
 
-  if (!mDependencies) {  
-    rv = NS_NewArray(getter_AddRefs(mDependencies));
-  } else {
-    rv = mDependencies->Clear();
-  }
-  NS_ENSURE_SUCCESS(rv, rv);
-  
+  nsresult rv;
   rv = nsXFormsUtils::EvaluateNodeBinding(mElement,
                                           kElementFlags,
                                           aBindingAttr,
@@ -169,7 +164,7 @@ nsXFormsControlStub::ProcessNodeBinding(const nsString          &aBindingAttr,
                                           aResultType,
                                           getter_AddRefs(mModel),
                                           aResult,
-                                          mDependencies);
+                                          &mDependencies);
 
   if (mModel) {
     mModel->AddFormControl(this);
diff --git a/extensions/xforms/nsXFormsControlStub.h b/extensions/xforms/nsXFormsControlStub.h
index d9364fb2efdf..3d82333d6f5b 100644
--- a/extensions/xforms/nsXFormsControlStub.h
+++ b/extensions/xforms/nsXFormsControlStub.h
@@ -39,7 +39,6 @@
 #ifndef nsXFormsControlStub_h_
 #define nsXFormsControlStub_h_
 
-#include "nsArray.h"
 #include "nsCOMPtr.h"
 #include "nsString.h"
 
@@ -86,7 +85,7 @@ public:
 
   // nsIXFormsControl
   NS_IMETHOD GetBoundNode(nsIDOMNode **aBoundNode);
-  NS_IMETHOD GetDependencies(nsIArray **aDependencies);
+  NS_IMETHOD GetDependencies(nsCOMArray<nsIDOMNode> **aDependencies);
   NS_IMETHOD GetElement(nsIDOMElement **aElement);
   NS_IMETHOD ResetBoundNode();
   NS_IMETHOD Bind();
@@ -126,7 +125,7 @@ protected:
   nsCOMPtr<nsIDOMNode>             mBoundNode;
 
   /** Array of nsIDOMNodes that the control depends on. */
-  nsCOMPtr<nsIMutableArray>        mDependencies;
+  nsCOMArray<nsIDOMNode>           mDependencies;
 
   /** The model for the control */
   nsCOMPtr<nsIModelElementPrivate> mModel;
diff --git a/extensions/xforms/nsXFormsMDGEngine.cpp b/extensions/xforms/nsXFormsMDGEngine.cpp
index 0191377e3d78..abd126ea9efc 100644
--- a/extensions/xforms/nsXFormsMDGEngine.cpp
+++ b/extensions/xforms/nsXFormsMDGEngine.cpp
@@ -46,6 +46,7 @@
 #include "nsIDOMXPathResult.h"
 #include "nsDeque.h"
 #include "nsIModelElementPrivate.h"
+#include "nsXFormsUtils.h"
 
 #ifdef DEBUG
 //#  define DEBUG_XF_MDG
@@ -149,13 +150,13 @@ nsXFormsMDGEngine::Init(nsIModelElementPrivate *aModel)
 }
 
 nsresult
-nsXFormsMDGEngine::AddMIP(ModelItemPropName      aType,
-                          nsIDOMXPathExpression *aExpression,
-                          nsXFormsMDGSet        *aDependencies,
-                          PRBool                 aDynFunc,
-                          nsIDOMNode            *aContextNode,
-                          PRInt32                aContextPos,
-                          PRInt32                aContextSize)
+nsXFormsMDGEngine::AddMIP(ModelItemPropName       aType,
+                          nsIDOMXPathExpression  *aExpression,
+                          nsCOMArray<nsIDOMNode> *aDependencies,
+                          PRBool                  aDynFunc,
+                          nsIDOMNode             *aContextNode,
+                          PRInt32                 aContextPos,
+                          PRInt32                 aContextSize)
 {
   NS_ENSURE_ARG(aContextNode);
   
@@ -193,7 +194,7 @@ nsXFormsMDGEngine::AddMIP(ModelItemPropName      aType,
     nsCOMPtr<nsIDOMNode> dep_domnode;
     nsXFormsMDGNode* dep_gnode;
     for (PRInt32 i = 0; i < aDependencies->Count(); ++i) {
-      dep_domnode = aDependencies->GetNode(i);
+      dep_domnode = aDependencies->ObjectAt(i);
       if (!dep_domnode) {
         return NS_ERROR_NULL_POINTER;
       }
@@ -241,9 +242,7 @@ nsXFormsMDGEngine::MarkNodeAsChanged(nsIDOMNode* aContextNode)
     NS_ENSURE_TRUE(mGraph.AppendElement(n), NS_ERROR_OUT_OF_MEMORY);
   }
 
-  NS_ENSURE_TRUE(mMarkedNodes.AddNode(aContextNode), NS_ERROR_FAILURE);
-
-  return NS_OK;
+  return mMarkedNodes.AppendObject(aContextNode);
 }
 
 #ifdef DEBUG_beaufour
@@ -292,7 +291,7 @@ nsXFormsMDGEngine::PrintDot(const char* aFile)
 #endif
 
 nsresult
-nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
+nsXFormsMDGEngine::Recalculate(nsCOMArray<nsIDOMNode> *aChangedNodes)
 {
   NS_ENSURE_ARG(aChangedNodes);
 
@@ -301,7 +300,7 @@ nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
          aChangedNodes->Count());
 #endif
 
-  NS_ENSURE_TRUE(aChangedNodes->AddSet(mMarkedNodes), NS_ERROR_OUT_OF_MEMORY);
+  NS_ENSURE_TRUE(aChangedNodes->AppendObjects(mMarkedNodes), NS_ERROR_OUT_OF_MEMORY);
 
   mMarkedNodes.Clear();
   
@@ -372,7 +371,7 @@ nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
                                   PR_FALSE,
                                   PR_TRUE);
         if (NS_SUCCEEDED(rv)) {
-          NS_ENSURE_TRUE(aChangedNodes->AddNode(g->mContextNode),
+          NS_ENSURE_TRUE(aChangedNodes->AppendObject(g->mContextNode),
                          NS_ERROR_FAILURE);
         }
       }
@@ -393,7 +392,7 @@ nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
       if (ns->IsConstraint() != constraint) {
         ns->Set(eFlag_CONSTRAINT, constraint);
         ns->Set(eFlag_DISPATCH_VALID_CHANGED, PR_TRUE);
-        NS_ENSURE_TRUE(aChangedNodes->AddNode(g->mContextNode),
+        NS_ENSURE_TRUE(aChangedNodes->AppendObject(g->mContextNode),
                        NS_ERROR_FAILURE);
       }
 
@@ -431,7 +430,7 @@ nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
         NS_ENSURE_SUCCESS(rv, rv);
       
         if (didChange) {
-          NS_ENSURE_TRUE(aChangedNodes->AddNode(g->mContextNode),
+          NS_ENSURE_TRUE(aChangedNodes->AppendObject(g->mContextNode),
                          NS_ERROR_FAILURE);
         }
       }
@@ -456,7 +455,7 @@ nsXFormsMDGEngine::Recalculate(nsXFormsMDGSet* aChangedNodes)
 
     g->MarkClean();
   }
-  aChangedNodes->MakeUnique();
+  nsXFormsUtils::MakeUniqueAndSort(aChangedNodes);
   
 #ifdef DEBUG_XF_MDG
   printf("\taChangedNodes: %d\n", aChangedNodes->Count());
@@ -950,11 +949,11 @@ nsXFormsMDGEngine::ComputeMIP(eFlag_t          aStateFlag,
 }
 
 nsresult
-nsXFormsMDGEngine::ComputeMIPWithInheritance(eFlag_t          aStateFlag,
-                                             eFlag_t          aDispatchFlag,
-                                             eFlag_t          aInheritanceFlag,
-                                             nsXFormsMDGNode *aNode,
-                                             nsXFormsMDGSet  *aSet)
+nsXFormsMDGEngine::ComputeMIPWithInheritance(eFlag_t                aStateFlag,
+                                             eFlag_t                aDispatchFlag,
+                                             eFlag_t                aInheritanceFlag,
+                                             nsXFormsMDGNode        *aNode,
+                                             nsCOMArray<nsIDOMNode> *aSet)
 {
   nsresult rv;
   PRBool didChange;
@@ -967,7 +966,7 @@ nsXFormsMDGEngine::ComputeMIPWithInheritance(eFlag_t          aStateFlag,
     if (   !(aStateFlag == eFlag_READONLY && ns->Test(aInheritanceFlag))
         ||  (aStateFlag == eFlag_RELEVANT && ns->Test(aInheritanceFlag)) )
     {
-      NS_ENSURE_TRUE(aSet->AddNode(aNode->mContextNode),
+      NS_ENSURE_TRUE(aSet->AppendObject(aNode->mContextNode),
                      NS_ERROR_FAILURE);
       rv = AttachInheritance(aSet,
                              aNode->mContextNode,
@@ -980,10 +979,10 @@ nsXFormsMDGEngine::ComputeMIPWithInheritance(eFlag_t          aStateFlag,
 }
 
 nsresult
-nsXFormsMDGEngine::AttachInheritance(nsXFormsMDGSet *aSet,
-                                     nsIDOMNode     *aSrc,
-                                     PRBool          aState,
-                                     eFlag_t         aStateFlag)
+nsXFormsMDGEngine::AttachInheritance(nsCOMArray<nsIDOMNode> *aSet,
+                                     nsIDOMNode             *aSrc,
+                                     PRBool                  aState,
+                                     eFlag_t                 aStateFlag)
 {
   NS_ENSURE_ARG(aSrc);
   
@@ -1043,7 +1042,7 @@ nsXFormsMDGEngine::AttachInheritance(nsXFormsMDGSet *aSet,
     if (updateNode) {
       rv = AttachInheritance(aSet, node, aState, aStateFlag);
       NS_ENSURE_SUCCESS(rv, rv);
-      NS_ENSURE_TRUE(aSet->AddNode(node), NS_ERROR_FAILURE);
+      NS_ENSURE_TRUE(aSet->AppendObject(node), NS_ERROR_FAILURE);
       updateNode = PR_FALSE;
     }
   }
diff --git a/extensions/xforms/nsXFormsMDGEngine.h b/extensions/xforms/nsXFormsMDGEngine.h
index 045a4a32fcee..08bb11929e16 100644
--- a/extensions/xforms/nsXFormsMDGEngine.h
+++ b/extensions/xforms/nsXFormsMDGEngine.h
@@ -42,13 +42,13 @@
 
 #include "nscore.h"
 #include "nsClassHashtable.h"
+#include "nsCOMArray.h"
 #include "nsCOMPtr.h"
 #include "nsVoidArray.h"
 
 #include "nsIDOMNode.h"
 
 #include "nsXFormsTypes.h"
-#include "nsXFormsMDGSet.h"
 #include "nsXFormsNodeState.h"
 #include "nsIModelElementPrivate.h"
 
@@ -177,10 +177,9 @@ protected:
   nsIModelElementPrivate *mModel;
   
   /**
-   * Set of nodes that are marked as changed, and should be included in
-   * recalculation
+   * Nodes that are marked as changed, and should be included in recalculation
    */
-  nsXFormsMDGSet mMarkedNodes;
+  nsCOMArray<nsIDOMNode> mMarkedNodes;
   
   /** Number of nodes in the graph */
   PRInt32 mNodesInGraph;
@@ -289,11 +288,11 @@ protected:
    * @param aNode            The context node
    * @param aSet             Set of the nodes influenced by operation
    */
-  nsresult ComputeMIPWithInheritance(eFlag_t          aStateFlag,
-                                     eFlag_t          aDispatchFlag,
-                                     eFlag_t          aInheritanceFlag,
-                                     nsXFormsMDGNode *aNode,
-                                     nsXFormsMDGSet  *aSet);
+  nsresult ComputeMIPWithInheritance(eFlag_t                 aStateFlag,
+                                     eFlag_t                 aDispatchFlag,
+                                     eFlag_t                 aInheritanceFlag,
+                                     nsXFormsMDGNode        *aNode,
+                                     nsCOMArray<nsIDOMNode> *aSet);
 
   /**
    * Attaches inheritance to all children of a given node
@@ -303,10 +302,10 @@ protected:
    * @param aState           The state of the flag
    * @param aStateFlag       The flag
    */
-  nsresult AttachInheritance(nsXFormsMDGSet *aSet,
-                             nsIDOMNode     *aSrc,
-                             PRBool          aState,
-                             eFlag_t         aStateFlag);
+  nsresult AttachInheritance(nsCOMArray<nsIDOMNode> *aSet,
+                             nsIDOMNode             *aSrc,
+                             PRBool                 aState,
+                             eFlag_t                aStateFlag);
 
   /**
    * Invalidate the information, ie. mark all nodes as dirty.
@@ -356,13 +355,13 @@ public:
    * @param aContextPos      The context positions of aExpression
    * @param aContextSize     The context size for aExpression
    */
-  nsresult AddMIP(ModelItemPropName      aType,
-                  nsIDOMXPathExpression *aExpression,
-                  nsXFormsMDGSet        *aDependencies,
-                  PRBool                 aDynFunc,
-                  nsIDOMNode            *aContextNode,
-                  PRInt32                aContextPos,
-                  PRInt32                aContextSize);
+  nsresult AddMIP(ModelItemPropName       aType,
+                  nsIDOMXPathExpression  *aExpression,
+                  nsCOMArray<nsIDOMNode> *aDependencies,
+                  PRBool                  aDynFunc,
+                  nsIDOMNode             *aContextNode,
+                  PRInt32                 aContextPos,
+                  PRInt32                 aContextSize);
 
   /**
    * Recalculate the MDG.
@@ -371,7 +370,7 @@ public:
    *
    * @note aChangedNodes are unique and sorted in pointer-order, ascending.
    */
-  nsresult Recalculate(nsXFormsMDGSet *aChangedNodes);
+  nsresult Recalculate(nsCOMArray<nsIDOMNode> *aChangedNodes);
 
   /**
    * Rebuilds the MDG.
diff --git a/extensions/xforms/nsXFormsModelElement.cpp b/extensions/xforms/nsXFormsModelElement.cpp
index 74fb6abb0830..87442c8356ed 100644
--- a/extensions/xforms/nsXFormsModelElement.cpp
+++ b/extensions/xforms/nsXFormsModelElement.cpp
@@ -573,12 +573,9 @@ nsXFormsModelElement::Revalidate()
     control->GetBoundNode(getter_AddRefs(boundNode));
 
     // Get dependencies
-    nsCOMPtr<nsIArray> deps;
-    control->GetDependencies(getter_AddRefs(deps));    
-    PRUint32 depCount = 0;
-    if (deps) {
-      deps->GetLength(&depCount);
-    }
+    nsCOMArray<nsIDOMNode> *deps = nsnull;
+    control->GetDependencies(&deps);    
+    PRUint32 depCount = deps ? deps->Count() : 0;
 
 #ifdef DEBUG_MODEL
     nsCOMPtr<nsIDOMElement> controlElement;
@@ -604,7 +601,7 @@ nsXFormsModelElement::Revalidate()
     PRBool refresh = PR_FALSE;
 
     for (PRInt32 j = 0; j < mChangedNodes.Count(); ++j) {
-      curChanged = mChangedNodes.GetNode(j);
+      curChanged = mChangedNodes[j];
 
       if (curChanged == boundNode) {
         refresh = PR_TRUE;
@@ -617,7 +614,7 @@ nsXFormsModelElement::Revalidate()
       }
 
       while (depPos < depCount && (void*) curChanged > (void*) curDep) {
-        curDep = do_QueryElementAt(deps, depPos);
+        curDep = deps->ObjectAt(depPos);
         ++depPos;
       }
 
@@ -1196,7 +1193,7 @@ nsXFormsModelElement::ProcessBind(nsIXFormsXPathEvaluator *aEvaluator,
   
 
   // Iterate over resultset
-  nsXFormsMDGSet set;
+  nsCOMArray<nsIDOMNode> deps;
   nsCOMPtr<nsIDOMNode> node;
   PRUint32 snapItem;
   for (snapItem = 0; snapItem < snapLen; ++snapItem) {
@@ -1265,14 +1262,14 @@ nsXFormsModelElement::ProcessBind(nsIXFormsXPathEvaluator *aEvaluator,
 
         // Get node dependencies
         nsAutoPtr<nsXFormsXPathNode> xNode(parser.Parse(propStrings[j]));
-        set.Clear();
-        rv = analyzer.Analyze(node, xNode, expr, &propStrings[j], &set);
+        deps.Clear();
+        rv = analyzer.Analyze(node, xNode, expr, &propStrings[j], &deps);
         NS_ENSURE_SUCCESS(rv, rv);
 
         // Insert into MDG
         rv = mMDG.AddMIP((ModelItemPropName) j,
                          expr,
-                         &set,
+                         &deps,
                          parser.UsesDynamicFunc(),
                          node,
                          snapItem + 1,
diff --git a/extensions/xforms/nsXFormsModelElement.h b/extensions/xforms/nsXFormsModelElement.h
index 8108f0b1a24b..d15ecc326137 100644
--- a/extensions/xforms/nsXFormsModelElement.h
+++ b/extensions/xforms/nsXFormsModelElement.h
@@ -149,7 +149,7 @@ private:
    * List of changed nodes, ie. nodes that have not been informed about
    * changes yet
    */
-  nsXFormsMDGSet    mChangedNodes;
+  nsCOMArray<nsIDOMNode>    mChangedNodes;
 
   /* Controls that need to a Refresh() */
   nsVoidArray       mControlsNeedingRefresh;
diff --git a/extensions/xforms/nsXFormsUtils.cpp b/extensions/xforms/nsXFormsUtils.cpp
index 84805c8debe7..4d31b6f49295 100644
--- a/extensions/xforms/nsXFormsUtils.cpp
+++ b/extensions/xforms/nsXFormsUtils.cpp
@@ -66,7 +66,6 @@
 #include "nsXFormsXPathAnalyzer.h"
 #include "nsXFormsXPathParser.h"
 #include "nsXFormsXPathNode.h"
-#include "nsXFormsMDGSet.h"
 #include "nsIDOMXPathExpression.h"
 #include "nsArray.h"
 
@@ -338,13 +337,13 @@ nsXFormsUtils::GetModel(nsIDOMElement  *aElement,
 }
 
 /* static */ already_AddRefed<nsIDOMXPathResult>
-nsXFormsUtils::EvaluateXPath(const nsAString &aExpression,
-                             nsIDOMNode      *aContextNode,
-                             nsIDOMNode      *aResolverNode,
-                             PRUint16         aResultType,
-                             PRInt32          aContextPosition,
-                             PRInt32          aContextSize,
-                             nsXFormsMDGSet  *aSet)
+nsXFormsUtils::EvaluateXPath(const nsAString        &aExpression,
+                             nsIDOMNode             *aContextNode,
+                             nsIDOMNode             *aResolverNode,
+                             PRUint16                aResultType,
+                             PRInt32                 aContextPosition,
+                             PRInt32                 aContextSize,
+                             nsCOMArray<nsIDOMNode> *aSet)
 {
   nsCOMPtr<nsIDOMDocument> doc;
   aContextNode->GetOwnerDocument(getter_AddRefs(doc));
@@ -435,7 +434,7 @@ nsXFormsUtils::EvaluateNodeBinding(nsIDOMElement           *aElement,
                                    PRUint16                 aResultType,
                                    nsIModelElementPrivate **aModel,
                                    nsIDOMXPathResult      **aResult,
-                                   nsIMutableArray         *aDeps)
+                                   nsCOMArray<nsIDOMNode>  *aDeps)
 {
   if (!aElement || !aModel || !aResult) {
     return NS_OK;
@@ -507,20 +506,13 @@ nsXFormsUtils::EvaluateNodeBinding(nsIDOMElement           *aElement,
   }
 
   // Evaluate |expr|
-  nsXFormsMDGSet set;
   nsCOMPtr<nsIDOMXPathResult> res = EvaluateXPath(expr,
                                                   contextNode,
                                                   aElement,
                                                   aResultType,
                                                   contextSize,
                                                   contextPosition,
-                                                  aDeps ? &set : nsnull);
-
-  if (res && aDeps) {
-    for (PRInt32 i = 0; i < set.Count(); ++i) {
-      aDeps->AppendElement(set.GetNode(i), PR_FALSE);
-    }
-  }
+                                                  aDeps);
 
   res.swap(*aResult); // exchanges ref
 
@@ -961,6 +953,30 @@ nsXFormsUtils::FocusControl(nsIDOMElement *aElement)
   return ret;
 }
 
+int
+sortFunc(nsIDOMNode *aNode1, nsIDOMNode *aNode2, void *aArg) 
+{
+  return (void*) aNode1 < (void*) aNode2;
+}
+
+/* static */ void
+nsXFormsUtils::MakeUniqueAndSort(nsCOMArray<nsIDOMNode> *aArray)
+{
+  if (!aArray)
+    return;
+
+  aArray->Sort(sortFunc, nsnull);  
+
+  PRInt32 pos = 0;
+  while (pos + 1 < aArray->Count()) {
+    if (aArray->ObjectAt(pos) == aArray->ObjectAt(pos + 1)) {
+      aArray->RemoveObjectAt(pos + 1);
+    } else {
+      ++pos;
+    }
+  }
+}
+
 /* static */ nsresult
 nsXFormsUtils::GetInstanceNodeForData(nsIDOMNode             *aInstanceDataNode,
                                       nsIModelElementPrivate *aModel,
diff --git a/extensions/xforms/nsXFormsUtils.h b/extensions/xforms/nsXFormsUtils.h
index b88650894053..6394aa16d032 100644
--- a/extensions/xforms/nsXFormsUtils.h
+++ b/extensions/xforms/nsXFormsUtils.h
@@ -42,15 +42,15 @@
 
 #include "prtypes.h"
 #include "nsCOMPtr.h"
+#include "nsCOMArray.h"
+#include "nsIDOMNode.h"
 #include "nsIDOMXPathResult.h"
 #include "nsIModelElementPrivate.h"
 
-class nsIDOMNode;
 class nsIDOMElement;
 class nsIXFormsModelElement;
 class nsIURI;
 class nsString;
-class nsXFormsMDGSet;
 class nsIMutableArray;
 
 #define NS_NAMESPACE_XFORMS              "http://www.w3.org/2002/xforms"
@@ -209,7 +209,7 @@ public:
                         PRUint16                 aResultType,
                         nsIModelElementPrivate **aModel,
                         nsIDOMXPathResult      **aResult,
-                        nsIMutableArray         *aDeps = nsnull);
+                        nsCOMArray<nsIDOMNode>  *aDeps = nsnull);
 
   /**
    * Given a bind element |aBindElement|, find the model and the context node
@@ -228,13 +228,13 @@ public:
    * namespace resolver, and result type.
    */
   static NS_HIDDEN_(already_AddRefed<nsIDOMXPathResult>)
-    EvaluateXPath(const nsAString &aExpression,
-                  nsIDOMNode      *aContextNode,
-                  nsIDOMNode      *aResolverNode,
-                  PRUint16         aResultType,
-                  PRInt32          aContextPosition = 1,
-                  PRInt32          aContextSize = 1,
-                  nsXFormsMDGSet  *aSet = nsnull);
+    EvaluateXPath(const nsAString        &aExpression,
+                  nsIDOMNode             *aContextNode,
+                  nsIDOMNode             *aResolverNode,
+                  PRUint16                aResultType,
+                  PRInt32                 aContextPosition = 1,
+                  PRInt32                 aContextSize = 1,
+                  nsCOMArray<nsIDOMNode> *aSet = nsnull);
 
   /**
    * Given a node in the instance data, get its string value according
@@ -330,6 +330,11 @@ public:
    */
   static NS_HIDDEN_(PRBool) FocusControl(nsIDOMElement *aElement);
 
+  /**
+   * Sorts the array and removes duplicate entries
+   */
+  static NS_HIDDEN_(void) MakeUniqueAndSort(nsCOMArray<nsIDOMNode> *aArray);
+
   /**
    * Returns the <xf:instance> for a given instance data node.
    */
diff --git a/extensions/xforms/nsXFormsXPathAnalyzer.cpp b/extensions/xforms/nsXFormsXPathAnalyzer.cpp
index 29e844df4a75..c8cc4006e2fd 100644
--- a/extensions/xforms/nsXFormsXPathAnalyzer.cpp
+++ b/extensions/xforms/nsXFormsXPathAnalyzer.cpp
@@ -39,6 +39,7 @@
 
 #include "nsXFormsXPathAnalyzer.h"
 #include "nsIDOMXPathResult.h"
+#include "nsXFormsUtils.h"
 
 #ifdef DEBUG
 //#define DEBUG_XF_ANALYZER
@@ -65,7 +66,7 @@ nsXFormsXPathAnalyzer::Analyze(nsIDOMNode              *aContextNode,
                                const nsXFormsXPathNode *aNode,
                                nsIDOMXPathExpression   *aExpression,
                                const nsAString         *aExprString,
-                               nsXFormsMDGSet          *aSet)
+                               nsCOMArray<nsIDOMNode>  *aSet)
 {
   NS_ENSURE_ARG(aContextNode);
   NS_ENSURE_ARG(aNode);
@@ -90,7 +91,7 @@ nsXFormsXPathAnalyzer::Analyze(nsIDOMNode              *aContextNode,
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Besides making the set a set, it also makes it sorted.
-  aSet->MakeUnique();
+  nsXFormsUtils::MakeUniqueAndSort(aSet);
 
   return NS_OK;
 }
@@ -196,7 +197,7 @@ nsXFormsXPathAnalyzer::AnalyzeRecursively(nsIDOMNode              *aContextNode,
 #ifdef DEBUG_XF_ANALYZER
         printf("collecting '%s'\n", NS_ConvertUCS2toUTF8(xp).get());
 #endif
-        mCurSet->AddNode(node);
+        mCurSet->AppendObject(node);
       }
       rv = AnalyzeRecursively(node, aNode->mChild, aIndent + 1);
     }
diff --git a/extensions/xforms/nsXFormsXPathAnalyzer.h b/extensions/xforms/nsXFormsXPathAnalyzer.h
index 9a24a5971b1f..85d00c3c9238 100644
--- a/extensions/xforms/nsXFormsXPathAnalyzer.h
+++ b/extensions/xforms/nsXFormsXPathAnalyzer.h
@@ -39,11 +39,11 @@
 
 #include "nscore.h"
 #include "nsCOMPtr.h"
+#include "nsCOMArray.h"
 #include "nsXFormsXPathNode.h"
 #include "nsIDOMXPathExpression.h"
 #include "nsIXFormsXPathEvaluator.h"
 #include "nsIDOMXPathNSResolver.h"
-#include "nsXFormsMDGSet.h"
 #include "nsIDOMNode.h"
 #include "nsCOMPtr.h"
 #include "nsString.h"
@@ -60,7 +60,7 @@ private:
   nsCOMPtr<nsIXFormsXPathEvaluator>  mEvaluator;
   nsCOMPtr<nsIDOMNode>            mResolver;
 
-  nsXFormsMDGSet                 *mCurSet;
+  nsCOMArray<nsIDOMNode>         *mCurSet;
   nsCOMPtr<nsIDOMXPathExpression> mCurExpression;
   const nsAString                *mCurExprString;
 
@@ -77,5 +77,5 @@ public:
                    const nsXFormsXPathNode *aNode,
                    nsIDOMXPathExpression   *aExpression,
                    const nsAString         *aExprString,
-                   nsXFormsMDGSet          *aSet);
+                   nsCOMArray<nsIDOMNode>  *aSet);
 };