From d01547fedb2aa7f1a0fc08004d7fe9d95ea22048 Mon Sep 17 00:00:00 2001
From: Bobby Holley <bobbyholley@gmail.com>
Date: Thu, 14 May 2015 15:38:55 -0700
Subject: [PATCH] Bug 1164977 - Prevent MediaStreamAudioSourceNode from passing
 null to nsIPrincipal::subsumes. r=padenot

---
 dom/media/webaudio/MediaStreamAudioSourceNode.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dom/media/webaudio/MediaStreamAudioSourceNode.cpp b/dom/media/webaudio/MediaStreamAudioSourceNode.cpp
index 52509a5a8b1a..6c9630f25a79 100644
--- a/dom/media/webaudio/MediaStreamAudioSourceNode.cpp
+++ b/dom/media/webaudio/MediaStreamAudioSourceNode.cpp
@@ -80,7 +80,7 @@ MediaStreamAudioSourceNode::PrincipalChanged(DOMMediaStream* aDOMMediaStream)
     if (doc) {
       nsIPrincipal* docPrincipal = doc->NodePrincipal();
       nsIPrincipal* streamPrincipal = mInputStream->GetPrincipal();
-      if (NS_FAILED(docPrincipal->Subsumes(streamPrincipal, &subsumes))) {
+      if (!streamPrincipal || NS_FAILED(docPrincipal->Subsumes(streamPrincipal, &subsumes))) {
         subsumes = false;
       }
     }