diff --git a/mozilla/layout/base/nsDocumentViewer.cpp b/mozilla/layout/base/nsDocumentViewer.cpp
index bddf220c303..df9796d1872 100644
--- a/mozilla/layout/base/nsDocumentViewer.cpp
+++ b/mozilla/layout/base/nsDocumentViewer.cpp
@@ -2187,6 +2187,9 @@ DocumentViewerImpl::MakeWindow(nsIWidget* aParentWidget,
   return rv;
 }
 
+// Return the selection for the document. Note that text fields have their
+// own selection, which cannot be accessed with this method. Use
+// mPresShell->GetSelectionForCopy() instead.
 nsresult DocumentViewerImpl::GetDocumentSelection(nsISelection **aSelection,
                                                   nsIPresShell *aPresShell)
 {
@@ -2265,6 +2268,7 @@ NS_IMETHODIMP DocumentViewerImpl::ClearSelection()
   nsresult rv;
   nsCOMPtr<nsISelection> selection;
 
+  // use mPresShell->GetSelectionForCopy() ?
   rv = GetDocumentSelection(getter_AddRefs(selection));
   if (NS_FAILED(rv)) return rv;
 
@@ -2278,6 +2282,8 @@ NS_IMETHODIMP DocumentViewerImpl::SelectAll()
   // functions to make this easier.
   nsCOMPtr<nsISelection> selection;
   nsresult rv;
+
+  // use mPresShell->GetSelectionForCopy() ?
   rv = GetDocumentSelection(getter_AddRefs(selection));
   if (NS_FAILED(rv)) return rv;
 
@@ -2343,9 +2349,10 @@ NS_IMETHODIMP DocumentViewerImpl::CopyImage(PRInt32 aCopyFlags)
 
 NS_IMETHODIMP DocumentViewerImpl::GetCopyable(PRBool *aCopyable)
 {
+  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_INITIALIZED);
+
   nsCOMPtr<nsISelection> selection;
-  nsresult rv;
-  rv = GetDocumentSelection(getter_AddRefs(selection));
+  nsresult rv = mPresShell->GetSelectionForCopy(getter_AddRefs(selection));
   if (NS_FAILED(rv)) return rv;
 
   PRBool isCollapsed;
@@ -2389,17 +2396,7 @@ NS_IMETHODIMP DocumentViewerImpl::GetContents(const char *mimeType, PRBool selec
 /* readonly attribute boolean canGetContents; */
 NS_IMETHODIMP DocumentViewerImpl::GetCanGetContents(PRBool *aCanGetContents)
 {
-  NS_ENSURE_ARG_POINTER(aCanGetContents);
-
-  nsCOMPtr<nsISelection> selection;
-  nsresult rv = GetDocumentSelection(getter_AddRefs(selection));
-  if (NS_FAILED(rv)) return rv;
-  
-  PRBool isCollapsed;
-  selection->GetIsCollapsed(&isCollapsed);
-  
-  *aCanGetContents = !isCollapsed;
-  return NS_OK;
+  return GetCopyable(aCanGetContents);
 }
 
 #ifdef XP_MAC
diff --git a/mozilla/layout/base/nsIPresShell.h b/mozilla/layout/base/nsIPresShell.h
index 4311f93624a..68ebd6bf1f5 100644
--- a/mozilla/layout/base/nsIPresShell.h
+++ b/mozilla/layout/base/nsIPresShell.h
@@ -88,6 +88,7 @@ class nsIDOMNode;
 class nsIStyleFrameConstruction;
 class nsIStyleSheet;
 class nsCSSFrameConstructor;
+class nsISelection;
 
 #define NS_IPRESSHELL_IID     \
 { 0x8be1b911, 0x7a04, 0x44e8, \
@@ -455,6 +456,12 @@ public:
    */
   NS_IMETHOD DoCopy() = 0;
 
+  /**
+   * Get the selection of the focussed element (either the page selection,
+   * or the selection for a text field).
+   */
+  NS_IMETHOD GetSelectionForCopy(nsISelection** outSelection) = 0;
+
   /**
    * Get link location.
    */
diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index 3dc813efdae..cb304554627 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -1120,6 +1120,8 @@ public:
   NS_IMETHOD NotifyDestroyingFrame(nsIFrame* aFrame);
   
   NS_IMETHOD DoCopy();
+  NS_IMETHOD GetSelectionForCopy(nsISelection** outSelection);
+
   NS_IMETHOD GetLinkLocation(nsIDOMNode* aNode, nsAString& aLocationString);
   NS_IMETHOD DoGetContents(const nsACString& aMimeType, PRUint32 aFlags, PRBool aSelectionOnly, nsAString& outValue);
 
@@ -1334,9 +1336,6 @@ protected:
   nsresult SetPrefNoScriptRule();
   nsresult SetPrefNoFramesRule(void);
 
-
-  nsresult GetSelectionForCopy(nsISelection** outSelection);
-
   nsICSSStyleSheet*         mPrefStyleSheet; // mStyleSet owns it but we maintain a ref, may be null
 #ifdef DEBUG
   PRUint32                  mUpdateCount;
@@ -4545,7 +4544,7 @@ NS_IMETHODIMP PresShell::GetLinkLocation(nsIDOMNode* aNode, nsAString& aLocation
   return NS_ERROR_FAILURE;
 }
 
-nsresult
+NS_IMETHODIMP
 PresShell::GetSelectionForCopy(nsISelection** outSelection)
 {
   nsresult rv = NS_OK;