1597507 - Audit nsIDocShellTreeItem usage in mozilla::AddonManagerWebAPI::IsAPIEnabled in toolkit/mozapps/extensions/AddonManagerWebAPI.cpp

Status: ASSIGNED

(Toolkit :: Add-ons Manager, defect, P2)

Description

[Kannan Vijayan [:djvj]]

In file toolkit/mozapps/extensions/AddonManagerWebAPI.cpp

There’s an explicit note about here about out-of-process issues not being in play:

• https://searchfox.org/mozilla-central/rev/6566d92dd46417a2f57e75c515135ebe84c9cef5/toolkit/mozapps/extensions/AddonManagerWebAPI.cpp#110

Simple bug - just change it to using BrowsingContext tree to get in-process same-type parent.

Comment 1

[Chris Peterson [:cpeterson]]

Kannan says replacing nsIDocShellTreeItem calls should block enabling Fission in Nightly (M6).

Comment 2

[Chris Peterson [:cpeterson]]

Moving to Add-ons Manager component.

Please audit this use of the nsIDocShellTreeItem interface. With Fission enabled, Documents and nsDocShells for related frames, such as subframes and parent documents, may not be available within the current process and the corresponding nsIDocShellTreeItem methods will return null

If this code works as-is with Fission, we don't need to remove this usage of nsIDocShellTreeItem until when we remove nsIDocShellTreeItem entirely (bug 1607591) after we ship Fission MVP.

Fission documentation about replacing nsIDocShellTree Item:
https://wiki.mozilla.org/Project_Fission/DocShell_Tree_Replace

:farre's presentation with examples of replacing nsIDocShellTreeItem with BrowsingContext, WindowContext, SyncedContexts, and BrowsingContextGroup:
https://docs.google.com/presentation/d/1K4j6ngty64TZjJNS5qH-MBoOm3TI2dJedVsbH8jUhKE/edit#slide=id.g6e35225e5d_1_264

Comment 3

[Chris Peterson [:cpeterson]]

Auditing whether this use of nsIDocShellTreeItem breaks when Fission is enabled blocks Fission Nightly.