From b21414912c9e24d461dc864ac2f68291777eda13 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Mon, 1 Dec 2014 15:27:19 -0500
Subject: [PATCH] Bug 966385 followup to make the review comment code actually
 compile.

---
 dom/base/nsXMLHttpRequest.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/dom/base/nsXMLHttpRequest.cpp b/dom/base/nsXMLHttpRequest.cpp
index 1fd32c43a4a9..3d3f80761ebb 100644
--- a/dom/base/nsXMLHttpRequest.cpp
+++ b/dom/base/nsXMLHttpRequest.cpp
@@ -2401,7 +2401,9 @@ GetRequestBody(nsIDOMDocument* aDoc, nsIInputStream** aResult,
                nsACString& aCharset)
 {
   aContentType.AssignLiteral("application/xml");
-  aCharset = aDoc->GetDocumentCharacterSet();
+  nsCOMPtr<nsIDocument> doc(do_QueryInterface(aDoc));
+  NS_ENSURE_STATE(doc);
+  aCharset = doc->GetDocumentCharacterSet();
 
   // Serialize to a stream so that the encoding used will
   // match the document's.