1597515 - Audit uses of mozilla::AppWindow::SetRootShellSize + SizeShellTo + SizeShell in xpfe/appshell/AppWindow.cpp

Status: NEW

(Core :: Window Management, defect, P3)

Description

[Kannan Vijayan [:djvj]]

In file xpfe/appshell/AppWindow.cpp

QueryInterfaces the root window’s docshell (mDocShell) to a Window and adjusts its size. DocShell and window should be in-process.

Marker bug - can be removed when docshelltree-item is removed, QI-ing the docshell directly instead of the tree-item.

Comment 1

[Chris Peterson [:cpeterson]]

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

Comment 2

[Chris Peterson [:cpeterson]]

Moving to Window Management component.

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

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]]

Neil, someone with appshell experience will need to triage this bug and audit this code for Fission.