From 39e63a698105dde7ff5092ba885089517e8311d5 Mon Sep 17 00:00:00 2001
From: wolfbeast <mcwerewolf@gmail.com>
Date: Sat, 17 Mar 2018 13:09:02 +0100
Subject: [PATCH] Use origin instead of documentURI for WebRTC permission
 requests, when available.

---
 browser/modules/ContentWebRTC.jsm | 1 +
 browser/modules/webrtcUI.jsm      | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/browser/modules/ContentWebRTC.jsm b/browser/modules/ContentWebRTC.jsm
index bfb98a868a..fd50176a03 100644
--- a/browser/modules/ContentWebRTC.jsm
+++ b/browser/modules/ContentWebRTC.jsm
@@ -208,6 +208,7 @@ function prompt(aContentWindow, aWindowID, aCallID, aConstraints, aDevices, aSec
   let request = {
     callID: aCallID,
     windowID: aWindowID,
+    origin: aContentWindow.origin,
     documentURI: aContentWindow.document.documentURI,
     secure: aSecure,
     requestTypes: requestTypes,
diff --git a/browser/modules/webrtcUI.jsm b/browser/modules/webrtcUI.jsm
index b24135bfc9..08de46bb34 100644
--- a/browser/modules/webrtcUI.jsm
+++ b/browser/modules/webrtcUI.jsm
@@ -290,7 +290,13 @@ function prompt(aBrowser, aRequest) {
   let {audioDevices: audioDevices, videoDevices: videoDevices,
        sharingScreen: sharingScreen, sharingAudio: sharingAudio,
        requestTypes: requestTypes} = aRequest;
-  let uri = Services.io.newURI(aRequest.documentURI, null, null);
+  let uri;
+  try {
+    // This fails for principals that serialize to "null", e.g. file URIs.
+    uri = Services.io.newURI(aRequest.origin, null, null);
+  } catch (e) {
+    uri = Services.io.newURI(aRequest.documentURI, null, null);
+  }
   let host = getHost(uri);
   let chromeDoc = aBrowser.ownerDocument;
   let chromeWin = chromeDoc.defaultView;