From de736f1c55ca59fc8d0bcb837250103aa5cadf72 Mon Sep 17 00:00:00 2001
From: Valentin Gosu <valentin.gosu@gmail.com>
Date: Tue, 19 Mar 2019 15:14:04 +0000
Subject: [PATCH] Bug 1532253 - Hold lock in mozilla::dom::IsType() r=baku

Differential Revision: https://phabricator.services.mozilla.com/D24018

--HG--
extra : moz-landing-system : lando
---
 dom/file/uri/BlobURLProtocolHandler.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dom/file/uri/BlobURLProtocolHandler.cpp b/dom/file/uri/BlobURLProtocolHandler.cpp
index 74d425a382dd..bad51c7ae1cc 100644
--- a/dom/file/uri/BlobURLProtocolHandler.cpp
+++ b/dom/file/uri/BlobURLProtocolHandler.cpp
@@ -956,8 +956,8 @@ namespace mozilla {
 namespace dom {
 
 bool IsType(nsIURI* aUri, DataInfo::ObjectType aType) {
-  MOZ_ASSERT(NS_IsMainThread(),
-             "without locking gDataTable is main-thread only");
+  // We lock because this may be called off-main-thread
+  StaticMutexAutoLock lock(sMutex);
   DataInfo* info = GetDataInfoFromURI(aUri);
   if (!info) {
     return false;