diff --git a/dom/events/UIEvent.cpp b/dom/events/UIEvent.cpp
index f80968cebde8..cabab0ce38ab 100644
--- a/dom/events/UIEvent.cpp
+++ b/dom/events/UIEvent.cpp
@@ -263,26 +263,6 @@ UIEvent::GetRangeParent()
   return nullptr;
 }
 
-NS_IMETHODIMP
-UIEvent::GetRangeParent(nsIDOMNode** aRangeParent)
-{
-  NS_ENSURE_ARG_POINTER(aRangeParent);
-  *aRangeParent = nullptr;
-  nsCOMPtr<nsINode> n = GetRangeParent();
-  if (n) {
-    CallQueryInterface(n, aRangeParent);
-  }
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-UIEvent::GetRangeOffset(int32_t* aRangeOffset)
-{
-  NS_ENSURE_ARG_POINTER(aRangeOffset);
-  *aRangeOffset = RangeOffset();
-  return NS_OK;
-}
-
 int32_t
 UIEvent::RangeOffset() const
 {
diff --git a/dom/interfaces/events/nsIDOMUIEvent.idl b/dom/interfaces/events/nsIDOMUIEvent.idl
index b53dc9b988fc..3912765ea7dd 100644
--- a/dom/interfaces/events/nsIDOMUIEvent.idl
+++ b/dom/interfaces/events/nsIDOMUIEvent.idl
@@ -46,8 +46,6 @@ interface nsIDOMUIEvent : nsISupports
   readonly attribute long               pageX;
   readonly attribute long               pageY;
   readonly attribute unsigned long      which;
-  readonly attribute nsIDOMNode         rangeParent;
-  readonly attribute long               rangeOffset;
 
   [notxpcom, nostdcall] EventPtr AsEvent();
 };
diff --git a/editor/libeditor/EditorEventListener.cpp b/editor/libeditor/EditorEventListener.cpp
index b6597b71cf69..9c00b7061689 100644
--- a/editor/libeditor/EditorEventListener.cpp
+++ b/editor/libeditor/EditorEventListener.cpp
@@ -694,14 +694,8 @@ EditorEventListener::HandleMiddleClickPaste(MouseEvent* aMouseEvent)
   }
 
   // Set the selection to the point under the mouse cursor:
-  nsCOMPtr<nsIDOMNode> parent;
-  if (NS_FAILED(aMouseEvent->GetRangeParent(getter_AddRefs(parent)))) {
-    return NS_ERROR_NULL_POINTER;
-  }
-  int32_t offset = 0;
-  if (NS_FAILED(aMouseEvent->GetRangeOffset(&offset))) {
-    return NS_ERROR_NULL_POINTER;
-  }
+  nsCOMPtr<nsINode> parent = aMouseEvent->GetRangeParent();
+  int32_t offset = aMouseEvent->RangeOffset();
 
   RefPtr<TextEditor> textEditor = mEditorBase->AsTextEditor();
   MOZ_ASSERT(textEditor);
diff --git a/editor/libeditor/HTMLEditorEventListener.cpp b/editor/libeditor/HTMLEditorEventListener.cpp
index ac030659c38b..e3121118c2fc 100644
--- a/editor/libeditor/HTMLEditorEventListener.cpp
+++ b/editor/libeditor/HTMLEditorEventListener.cpp
@@ -112,14 +112,10 @@ HTMLEditorEventListener::MouseDown(MouseEvent* aMouseEvent)
     NS_ENSURE_TRUE(selection, NS_OK);
 
     // Get location of mouse within target node
-    nsCOMPtr<nsIDOMNode> parent;
-    rv = aMouseEvent->GetRangeParent(getter_AddRefs(parent));
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsINode> parent = aMouseEvent->GetRangeParent();
     NS_ENSURE_TRUE(parent, NS_ERROR_FAILURE);
 
-    int32_t offset = 0;
-    rv = aMouseEvent->GetRangeOffset(&offset);
-    NS_ENSURE_SUCCESS(rv, rv);
+    int32_t offset = aMouseEvent->RangeOffset();
 
     // Detect if mouse point is within current selection for context click
     bool nodeIsInSelection = false;
@@ -133,7 +129,9 @@ HTMLEditorEventListener::MouseDown(MouseEvent* aMouseEvent)
           continue;
         }
 
-        range->IsPointInRange(parent, offset, &nodeIsInSelection);
+        IgnoredErrorResult err;
+        nodeIsInSelection =
+          range->IsPointInRange(*parent, offset, err) && !err.Failed();
 
         // Done when we find a range that we are in
         if (nodeIsInSelection) {