This bug was filed from the Socorro interface and is report bp-8149661c-dd64-4b8d-aa4c-b07280171117. ============================================================= Top 10 frames of crashing thread: 0 xul.dll mozilla::camera::VideoEngine::CreateVideoCapture dom/media/systemservices/VideoEngine.cpp:51 1 xul.dll <lambda_08cbd13f79f629363b36fc2f39d9a0c6>::operator dom/media/systemservices/CamerasParent.cpp:724 2 xul.dll MessageLoop::DoWork ipc/chromium/src/base/message_loop.cc:535 3 xul.dll mozilla::ipc::MessagePumpForNonMainUIThreads::DoRunLoop ipc/glue/MessagePump.cpp:403 4 xul.dll base::MessagePumpWin::Run ipc/chromium/src/base/message_pump_win.h:80 5 xul.dll MessageLoop::RunHandler ipc/chromium/src/base/message_loop.cc:319 6 xul.dll MessageLoop::Run ipc/chromium/src/base/message_loop.cc:299 7 xul.dll base::Thread::ThreadMain ipc/chromium/src/base/thread.cc:181 8 xul.dll `anonymous namespace'::ThreadFunc ipc/chromium/src/base/platform_thread_win.cc:28 9 kernel32.dll BaseThreadInitThunk ============================================================= There is 1 crash in nightly 59.0a1 with buildid 20171116220410. In analyzing the backtrace, the regression may have been introduced by patch [1] to fix bug 1399413. [1] https://hg.mozilla.org/mozilla-central/rev/08ae44b6836c

Just got it on a win 10 Dell XPS 13 https://crash-stats.mozilla.com/report/index/b75a946f-c295-4752-8fcf-7caf00171119 Also when I go to gum test -> Video I get: Failed allocate videosource

navigator.mediaDevices.enumerateDevices().then( v => v.forEach(d => console.log(d.kind + " " + d.deviceId))) Promise { <state>: "pending" } videoinput IWrHEk8CFMmqO8/ZwY/pOc8Fas1soq3W6silAAVHtj4= debugger eval code:1:69 audioinput 8ZjghNrcyTW4ZQamfI46V2O+HkxtWqenuz/i++/ZQKQ= debugger eval code:1:69 audioinput M7kkQ7hqzWP2X+OJvKmx4Za1ywrZ7tclT+Mhaxgirk0= debugger eval code:1:69 audioinput oe+55gzOZZlMUXXqZV0ykBtgqlGvIX2bzatOAWd8Aus=

We need more information to figure out the crash root cause.

Munro, can you get a minidump from crash-stats, validate the fact that there is a nullptr here, and null-check, so, at least, we don't crash? Ping me on irc if you don't know how to get a minidump, or to debug using it.

Comment on attachment 8931548 [details] Bug 1418331 - add null protection. https://reviewboard.mozilla.org/r/202676/#review208592 LGTM

I will analyze the minidump first.

The minidump shows that it.second.VideoCapture() == null. It's possibly because webrtc::VideoCaptureFactory::Create() or webrtc::DesktopCaptureImpl::Create() return nullptr. I will add some null protection and MOZ_ASSERT to diagnose further.

Pushed by mchiang@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/4ca7e0cfe84e add null protection. r=drno