1643509 - Crash in [@ mozilla::dom::PContentParent::SendUpdateMediaControlKeysEvent]

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect, P2)

Description

[Andrew McCreight [:mccr8]]

This bug is for crash report bp-d56f29b0-5b89-4ae7-a779-a20130200531.

Top 10 frames of crashing thread:

0 libxul.so void mozilla::ipc::WriteIPDLParam<mozilla::dom::MediaControlKeysEvent const&> ipc/glue/IPDLParamTraits.h:62
1 libxul.so mozilla::dom::PContentParent::SendUpdateMediaControlKeysEvent ipc/ipdl/PContentParent.cpp:4656
2 libxul.so mozilla::dom::CanonicalBrowsingContext::UpdateMediaControlKeysEvent docshell/base/CanonicalBrowsingContext.cpp:362
3 libxul.so mozilla::dom::MediaController::UpdateMediaControlKeysEventToContentMediaIfNeeded dom/media/mediacontrol/MediaController.cpp:109
4 libxul.so mozilla::dom::MediaControlKeysHandler::OnKeyPressed dom/media/mediacontrol/MediaControlKeysEvent.cpp:42
5 libxul.so mozilla::dom::MediaControlKeysManager::OnKeyPressed dom/media/mediacontrol/MediaControlKeysManager.cpp:94
6 libxul.so mozilla::widget::MPRISServiceHandler::EmitEvent widget/gtk/MPRISServiceHandler.cpp:666
7 libxul.so mozilla::widget::HandleMethodCall widget/gtk/MPRISServiceHandler.cpp:82
8 libgio-2.0.so.0 g_dbus_connection_signal_unsubscribe 
9 libglib-2.0.so.0 g_main_context_dispatch 

The crash reason is MOZ_RELEASE_ASSERT(EnumValidator::IsLegalValue(aValue)). I see one crash on Nightly build 20200530211958, and a few more recent. Maybe this is related to bug 1640339?

Comment 1

[Alastor Wu [:alwu]]

probably, but I will remove MediaControlKeysEvent in bug1640998, so this crash should be fixed after finishing that bug.

Comment 2

[Andrew McCreight [:mccr8]]

Great. Keep in mind that this crash has already made it to 78, so whatever fix happens will need to land there.

Comment 3

[Alastor Wu [:alwu]]

Ah, wait, I've found the problem, it's a simple fix.

Comment 4

[Alastor Wu [:alwu]]

Attachment: Bug 1643509 - update `ParamTraits<mozilla::dom::MediaControlKeysEvent>` to sync with `MediaControlKeysEvent`

The first value in MediaControlKeysEvent is eFocus, so we should also update its ParamTraits.

[1] https://searchfox.org/mozilla-central/rev/598e50d2c3cd81cd616654f16af811adceb08f9f/dom/media/mediacontrol/MediaControlKeysEvent.h#23

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/020c2356f7c9
update `ParamTraits<mozilla::dom::MediaControlKeysEvent>` to sync with `MediaControlKeysEvent` r=mccr8

Comment 6

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/020c2356f7c9

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:alwu, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 8

[Alastor Wu [:alwu]]

Comment on attachment 9154397 [details]
Bug 1643509 - update ParamTraits<mozilla::dom::MediaControlKeysEvent> to sync with MediaControlKeysEvent

Beta/Release Uplift Approval Request

• User impact if declined: Crash on Linux when user hits a certain media key
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This change adds the focus key into the IPC serialized type, which is a really minor change.
• String changes made/needed:

Comment 9

[Julien Cristau [:jcristau]]

We don't seem to see crashes for this outside of nightly, is this maybe only happening with media.hardwaremediakeys.enabled?

Comment 10

[Alastor Wu [:alwu]]

Yes, once you enable this pref and you can reproduce this crash on Linux when a user sends focus media key.

Comment 11

[Julien Cristau [:jcristau]]

OK, that doesn't seem worth worrying about then.