--- a/content/html/content/src/HTMLInputElement.cpp
+++ b/content/html/content/src/HTMLInputElement.cpp
@@ -319,16 +319,20 @@ HTMLInputElement::nsFilePickerShownCallb
 
   // Collect new selected filenames
   nsCOMArray<nsIDOMFile> newFiles;
   if (mMulti) {
     nsCOMPtr<nsISimpleEnumerator> iter;
     nsresult rv = mFilePicker->GetDomfiles(getter_AddRefs(iter));
     NS_ENSURE_SUCCESS(rv, rv);
 
+    if (!iter) {
+      return NS_OK;
+    }
+
     nsCOMPtr<nsISupports> tmp;
     bool prefSaved = false;
     bool loop = true;
 
     while (NS_SUCCEEDED(iter->HasMoreElements(&loop)) && loop) {
       iter->GetNext(getter_AddRefs(tmp));
       nsCOMPtr<nsIDOMFile> domFile = do_QueryInterface(tmp);
       MOZ_ASSERT(domFile);