It sounds to me like we should update the nsIChannel implementations whose `GetInterface` method returns `NS_ERROR_FAILURE` at all to return `NS_ERROR_NO_INTERFACE` instead. The websocket case looks like https://searchfox.org/mozilla-central/rev/202a285024f174c2d2bf2152d9cba90a03723eab/netwerk/protocol/websocket/WebSocketChannel.cpp#3035 to me . In https://searchfox.org/mozilla-central/source/netwerk/protocol/websocket/WebSocketChannelParent.cpp#274-289 , getting the auth prompt could return something else, but given comment #11 that seems unlikely. Otherwise it'll just return whatever `QueryInterface` returns, which should be well-behaved, too.
Bug 1179250 Comment 13 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
It sounds to me like we should update the nsIChannel implementations whose `GetInterface` method returns `NS_ERROR_FAILURE` at all to return `NS_ERROR_NO_INTERFACE` instead. The websocket case looks like https://searchfox.org/mozilla-central/rev/202a285024f174c2d2bf2152d9cba90a03723eab/netwerk/protocol/websocket/WebSocketChannel.cpp#3035 to me . In https://searchfox.org/mozilla-central/source/netwerk/protocol/websocket/WebSocketChannelParent.cpp#274-289 , getting the auth prompt could return something else, but given comment #11 that seems unlikely to be what's at issue here. Otherwise it'll just return whatever `QueryInterface` returns, which should be well-behaved, too.