diff --git a/mozilla/widget/src/xpwidgets/nsBaseFilePicker.cpp b/mozilla/widget/src/xpwidgets/nsBaseFilePicker.cpp
index fa8a6000176..a91054294e1 100644
--- a/mozilla/widget/src/xpwidgets/nsBaseFilePicker.cpp
+++ b/mozilla/widget/src/xpwidgets/nsBaseFilePicker.cpp
@@ -42,6 +42,8 @@
 #include "nsIDOMWindow.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIDocShell.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIInterfaceRequestorUtils.h"
 #include "nsIBaseWindow.h"
 #include "nsIContentViewer.h"
 #include "nsIDocumentViewer.h"
@@ -81,8 +83,24 @@ nsIWidget *nsBaseFilePicker::DOMWindowToWidget(nsIDOMWindow *dw)
   if (sgo) {
     nsCOMPtr<nsIBaseWindow> baseWin(do_QueryInterface(sgo->GetDocShell()));
 
-    if (baseWin) {
+    while (!widget && baseWin) {
       baseWin->GetParentWidget(getter_AddRefs(widget));
+      if (!widget) {
+        nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(baseWin));
+        if (!docShellAsItem)
+          return nsnull;
+
+        nsCOMPtr<nsIDocShellTreeItem> parent;
+        docShellAsItem->GetSameTypeParent(getter_AddRefs(parent));
+        if (!parent)
+          return nsnull;
+
+        sgo = do_GetInterface(parent);
+        if (!sgo)
+          return nsnull;
+
+        baseWin = do_QueryInterface(sgo->GetDocShell());
+      }
     }
   }