This bug is for crash report bp-66a50ea2-510c-4cc2-9adb-62fa60200609.

Top 10 frames of crashing thread:

0 XUL mozilla::dom::MediaStatusManager::EnableAction dom/media/mediacontrol/MediaStatusManager.cpp:313
1 XUL mozilla::dom::ContentParent::RecvNotifyMediaSessionSupportedActionChanged dom/ipc/ContentParent.cpp:6149
2 XUL mozilla::dom::PContentParent::OnMessageReceived ipc/ipdl/PContentParent.cpp:11562
3 XUL mozilla::ipc::MessageChannel::DispatchMessage ipc/glue/MessageChannel.cpp:2166
4 XUL mozilla::ipc::MessageChannel::MessageTask::Run ipc/glue/MessageChannel.cpp:1969
5 XUL nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:1236
6 XUL NS_ProcessPendingEvents xpcom/threads/nsThreadUtils.cpp:449
7 XUL nsAppShell::ProcessGeckoEvents widget/cocoa/nsAppShell.mm:429
8 CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 
9 CoreFoundation __CFRunLoopDoSource0 

There is 1 crash in nightly 79 with buildid 20200609092134. In analyzing the backtrace, the regression may have been introduced by patch [1] to fix bug 1640998.

[1] https://hg.mozilla.org/mozilla-central/rev?node=3502f8c7a17d

Still can not figure out how did we enable the same action twice, because we would only update the action change when the action handler is set from null to something or from something to nothing. In addition, the browsing context Id for a media session is always unchanged, so it's guarantee to set the action on the correct MediaSessionInfo.

However, in order to avoid having more crashes, I have to change the assertions to early returns and add logs to help us be aware of this issue if it happens again.

[1] https://searchfox.org/mozilla-central/rev/fac90408bcf52ca88a3dcd2ef30a379b68ab24e2/dom/media/mediasession/MediaSession.cpp#71-75

So, I reluctantly left irc://irc.freenode.net/firefox to report the fact that Jitsi Meet server seemed to be broken in Nightly as of a few days ago, but working in Stable. That is, Jitsi was showing animation that my mic was working, and I could hear the join/quit sounds, but none of the other sounds from other people.

chat.mozilla.org has crashed twice on me. First time was on accessing it with a crashed tab, then when I clicked ok on reporting the crash, the browser crashed with https://crash-stats.mozilla.org/report/index/8e4c52e4-cbd3-4ed1-8bba-996060200609

I restarted, tried once again, crashed almost immediately https://crash-stats.mozilla.org/report/index/eef213e4-485f-403f-b617-41c7e0200609

Both times I was in private browsing, in nightly, with noscript whitelisting.

At that point I gave up on reporting the Jitsi Meet issue, but I wonder if it was related to this one, since it's a recent media fail.

https://hg.mozilla.org/mozilla-central/rev/37510e9b92b2