1572852 - Fix usage of nsIDocShellTreeItem in LogDocShellTree

Status: RESOLVED FIXED

(Core :: Disability Access APIs, enhancement, P3)

Description

[Kannan Vijayan [:djvj]]

In accessible/base/Logging.cpp, within the LogDocShellTree function (https://searchfox.org/mozilla-central/source/accessible/base/Logging.cpp#120):

This function calls GetInProcessParent() and GetInProcessRootTreeItem() on nsIDocShellTreeItem. The result simply logged via printf.

This logging will be incorrect post-fission. The parent may now be null when it is out-of-process, and the in-process root may not be the actual root.

Since the printf dumps the raw pointers, there's not much meaning to the actual dumped line. Changing the printf message to indicate that this is showing in-process TreeItems should be sufficient.

Comment 1

[Chris Peterson [:cpeterson]]

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

Comment 2

[Nika Layzell [:nika] (ni? for response)]

This method is used only for a11y development, and is not called anywhere unless accessibility logging is enabled.

As this doesn't directly impact the functionality of firefox with fission enabled, moving to future.

Comment 3

[James Teh [:Jamie]]

Attachment: Bug 1572852: a11y::Logging::LogDocShellTree: Make it clear that this is in-process DocShell tree info.

For an OOP iframe, the logged parent will be null and the logged root won't be the real top level document.
This is just the way things are and this might still be useful info sometimes, so we still log it, but make it clear in the log message that it's about the in-process tree.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/553af70f2690
a11y::Logging::LogDocShellTree: Make it clear that this is in-process DocShell tree info. r=yzen

Comment 5

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/553af70f2690