1574100 - Assertion failure: aLayer.GetReferentId(), at APZCTreeManager.cpp:835

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect)

Description

[Hiroyuki Ikezoe (:hiro)]

Attachment: Patch including a browser test which causes the assertion

I am less sure this is a fission specific issue or not.

Attaching file is a patch including a browser mochitest which causes this assertion.

I am going to post a backtrace for the assertion in the next comment.

Comment 1

[Hiroyuki Ikezoe (:hiro)]

Attachment: backtrace

Comment 2

[Hiroyuki Ikezoe (:hiro)]

Attachment: A browser test to reproduce the assertion

The patch I posted didn't include browser.ini file. Sorry for that.

Comment 3

[Botond Ballo [:botond]]

The test times out for me, but it doesn't reproduce the assertion.

Comment 4

[Botond Ballo [:botond]]

Correction: I can reproduce the assertion, if I run the test normally. (Before, I was running it with xvfb-run, that seems to interfere with this test somehow.)

Comment 5

[Botond Ballo [:botond]]

I think I see what's happening: in cases where a RefLayer has multiple frame metrics, only the bottom LayerMetricsWrapper conceptually represents the ref layer for purposes of building the hit-testing tree. Accordingly, LayerMetricsWrapper should only return RefLayer properties if AtBottomLayer() is true.

This is done correctly in GetReferentId(), but not in GetEventRegionsOverride().

Comment 6

[Botond Ballo [:botond]]

Attachment: Bug 1574100 - For RefLayers with multiple metrics, only expose the event regions override for the bottom one. r=tnikkel

We only want the bottom LayerMetricsWrapper / WebRenderScrollDataWrapper to
be treated as a ref layer, and only ref layers have event regions overrides.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4229066f4943
For RefLayers with multiple metrics, only expose the event regions override for the bottom one. r=tnikkel

Comment 8

[Botond Ballo [:botond]]

(In reply to Hiroyuki Ikezoe (:hiro) from comment #0)

I am less sure this is a fission specific issue or not.

This is unlikely to affect non-Fission. While theoretically possible, it would require the browser UI to be scrollable, or something like that.

Comment 9

[Hiroyuki Ikezoe (:hiro)]

Thanks for the quick fix! Amazing!

Comment 10

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/4229066f4943