1682045 - OneShotPostRefreshObserver can possibly leak and also leak presShell

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Sean Feng [:sefeng211]]

We added it as a raw pointer to the observer array here https://searchfox.org/mozilla-central/rev/0bcf81557b89e7757c44e25bb4bc7f4cb8619dc9/dom/base/nsDOMWindowUtils.cpp#2791 and https://searchfox.org/mozilla-central/source/layout/xul/nsSliderFrame.cpp#994, and this object will only delete itself if DidRefresh is called which is bad. If it leaks, it'll also leak presShell.

I'll submit a patch to fix it.

Comment 1

[Sean Feng [:sefeng211]]

Attachment: Bug 1682045 - Allow nsPresContext to store and release the last registered OneShotPostRefreshObserver

OneShotPostRefreshObserver works as the caller registers it, and
let it deletes itself via the DidRefresh method. The issue is that
DidRefresh is not guaranteed to run, and it'll leak PresShell
if it doesn't run.

This patch allows nsPresContext to store and release the last
registered OneShotPostRefreshObserver, and converted the existing
usage of OneShotPostRefreshObserver to use that. So instead of asking
OneShotPostRefreshObserver to delete itself, we now ask nsPresContext
to release it.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a0cde344a949
Allow nsPresContext to store and release the last registered OneShotPostRefreshObserver r=smaug

Comment 3

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/a0cde344a949