diff --git a/mozilla/content/base/src/nsDocumentViewer.cpp b/mozilla/content/base/src/nsDocumentViewer.cpp
index fb33ddba053..1568996078a 100644
--- a/mozilla/content/base/src/nsDocumentViewer.cpp
+++ b/mozilla/content/base/src/nsDocumentViewer.cpp
@@ -422,6 +422,7 @@ protected:
   PRPackedBool  mEnableRendering;
   PRPackedBool  mStopped;
   PRPackedBool  mLoaded;
+  PRPackedBool  mDeferredWindowClose;
   PRInt16 mNumURLStarts;
   PRInt16 mDestroyRefCount;     // a second "refcount" for the document viewer's "destroy"
 
@@ -486,6 +487,7 @@ void DocumentViewerImpl::PrepareToStartLoad()
   mEnableRendering  = PR_TRUE;
   mStopped          = PR_FALSE;
   mLoaded           = PR_FALSE;
+  mDeferredWindowClose = PR_FALSE;
 
 #ifdef NS_PRINTING
   mPrintIsPending        = PR_FALSE;
@@ -1585,6 +1587,21 @@ DocumentViewerImpl::GetEnableRendering(PRBool* aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+DocumentViewerImpl::RequestWindowClose(PRBool* aCanClose)
+{
+#ifdef NS_PRINTING
+  if (mPrintIsPending || (mPrintEngine && mPrintEngine->GetIsPrinting())) {
+    *aCanClose = PR_FALSE;
+    mDeferredWindowClose = PR_TRUE;
+  } else
+#endif
+    *aCanClose = PR_TRUE;
+
+  return NS_OK;
+}
+
+
 void
 DocumentViewerImpl::ForceRefresh()
 {
@@ -3817,7 +3834,12 @@ DocumentViewerImpl::OnDonePrinting()
     }
 
     // We are done printing, now cleanup 
-    if (mClosingWhilePrinting) {
+    if (mDeferredWindowClose) {
+      mDeferredWindowClose = PR_FALSE;
+      nsCOMPtr<nsIDOMWindowInternal> win = do_GetInterface(mContainer);
+      if (win)
+        win->Close();
+    } else if (mClosingWhilePrinting) {
       if (mDocument) {
         mDocument->SetScriptGlobalObject(nsnull);
         mDocument = nsnull;
diff --git a/mozilla/docshell/base/nsIContentViewer.idl b/mozilla/docshell/base/nsIContentViewer.idl
index 6b2b00fcba3..6489b9cb8a8 100644
--- a/mozilla/docshell/base/nsIContentViewer.idl
+++ b/mozilla/docshell/base/nsIContentViewer.idl
@@ -59,4 +59,12 @@ interface nsIContentViewer : nsISupports
   attribute boolean enableRendering;
 
   attribute boolean sticky;
+
+  /*
+   * This is called when the DOM window wants to be closed.  Returns true
+   * if the window can close immediately.  Otherwise, returns false and will
+   * close the DOM window as soon as practical.
+   */
+
+  boolean requestWindowClose();
 };
diff --git a/mozilla/dom/src/base/nsGlobalWindow.cpp b/mozilla/dom/src/base/nsGlobalWindow.cpp
index 88553505d8a..53bedde68e1 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.cpp
+++ b/mozilla/dom/src/base/nsGlobalWindow.cpp
@@ -3344,6 +3344,20 @@ GlobalWindowImpl::Close()
     }
   }
 
+  // Ask the content viewer whether the toplevel window can close.
+  // If the content viewer returns false, it is responsible for calling
+  // Close() as soon as it is possible for the window to close.
+  // This allows us to not close the window while printing is happening.
+
+  nsCOMPtr<nsIContentViewer> cv;
+  mDocShell->GetContentViewer(getter_AddRefs(cv));
+  if (cv) {
+    PRBool canClose;
+    cv->RequestWindowClose(&canClose);
+    if (!canClose)
+      return NS_OK;
+  }
+
   // Fire a DOM event notifying listeners that this window is about to
   // be closed. The tab UI code may choose to cancel the default
   // action for this event, if so, we won't actually close the window
diff --git a/mozilla/layout/base/nsDocumentViewer.cpp b/mozilla/layout/base/nsDocumentViewer.cpp
index fb33ddba053..1568996078a 100644
--- a/mozilla/layout/base/nsDocumentViewer.cpp
+++ b/mozilla/layout/base/nsDocumentViewer.cpp
@@ -422,6 +422,7 @@ protected:
   PRPackedBool  mEnableRendering;
   PRPackedBool  mStopped;
   PRPackedBool  mLoaded;
+  PRPackedBool  mDeferredWindowClose;
   PRInt16 mNumURLStarts;
   PRInt16 mDestroyRefCount;     // a second "refcount" for the document viewer's "destroy"
 
@@ -486,6 +487,7 @@ void DocumentViewerImpl::PrepareToStartLoad()
   mEnableRendering  = PR_TRUE;
   mStopped          = PR_FALSE;
   mLoaded           = PR_FALSE;
+  mDeferredWindowClose = PR_FALSE;
 
 #ifdef NS_PRINTING
   mPrintIsPending        = PR_FALSE;
@@ -1585,6 +1587,21 @@ DocumentViewerImpl::GetEnableRendering(PRBool* aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+DocumentViewerImpl::RequestWindowClose(PRBool* aCanClose)
+{
+#ifdef NS_PRINTING
+  if (mPrintIsPending || (mPrintEngine && mPrintEngine->GetIsPrinting())) {
+    *aCanClose = PR_FALSE;
+    mDeferredWindowClose = PR_TRUE;
+  } else
+#endif
+    *aCanClose = PR_TRUE;
+
+  return NS_OK;
+}
+
+
 void
 DocumentViewerImpl::ForceRefresh()
 {
@@ -3817,7 +3834,12 @@ DocumentViewerImpl::OnDonePrinting()
     }
 
     // We are done printing, now cleanup 
-    if (mClosingWhilePrinting) {
+    if (mDeferredWindowClose) {
+      mDeferredWindowClose = PR_FALSE;
+      nsCOMPtr<nsIDOMWindowInternal> win = do_GetInterface(mContainer);
+      if (win)
+        win->Close();
+    } else if (mClosingWhilePrinting) {
       if (mDocument) {
         mDocument->SetScriptGlobalObject(nsnull);
         mDocument = nsnull;