1493250 - Buttons scroll with weird parallax effect on scrolling

Status: RESOLVED DUPLICATE of bug 1501342

(Core :: Graphics, defect, P3)

Description

[Mike Taylor [:miketaylr]]

Attachment: 38196565-7aacc9a8-368c-11e8-871f-bb092eb717c9.gif

In Fennec, or Focus/GeckoView,

1. go to https://www.gty.org/broadcasts/radio/schedule.
2. scroll up and down

ER. sermon button scrolls with its container
AR. sermon button does some wacky Sega Genesis vertical parallax stuff

Comment 1

[Mike Taylor [:miketaylr]]

(sorry for terrible title)

Comment 2

[Kevin Brosnan [Ex-Mozilla]]

Got this to a one day regression range. Several good candidates in that range. Bz, jchen and mstrange. Going to check if I have a working build environment for early 2017 Fennec.  

12:45.44 INFO: Got as far as we can go bisecting nightlies...
12:45.44 INFO: Last good revision: f985243bb630b2c78cd57731c8d8ab191aa09527 (2017-02-02)
12:45.44 INFO: First bad revision: bf15d4078c2a6db7df37ab466d28a1e075c9eb4d (2017-02-03)
12:45.44 INFO: Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=f985243bb630b2c78cd57731c8d8ab191aa09527&tochange=bf15d4078c2a6db7df37ab466d28a1e075c9eb4d

Comment 3

[Jan Henning [:JanH]]

I need to dig them up again, but I remember we had at least one or two other bugs with that sort of unintended parallax effect.

Comment 4

[Kevin Brosnan [Ex-Mozilla]]

The first bad revision is:
changeset:   332056:5746c9b9db68
user:        Markus Stange <[e-mail]>
date:        Fri Jan 27 17:38:55 2017 +0100
summary:     Bug 1298218 - Add a workaround for root scroll frame container layer scrolling. r=tnikkel

Comment 5

[David Bolter [:davidb] (NeedInfo me for attention)]

Over to GFX for triage.

Comment 6

[Markus Stange [:mstange]]

Botond, do you think you could take a look at this one?

Comment 7

[Botond Ballo [:botond]]

This triggers the following assertion failure in debug mode, making it an APZLayout issue:

Assertion failure: false (Two layers that scroll together have different ancestor transforms), at /home/botond/dev/mozilla/central/gfx/layers/apz/src/APZCTreeManager.cpp:1122

Comment 8

[Botond Ballo [:botond]]

*And*, for good measure, the assertion in bug 1427792 too.

Comment 9

[Botond Ballo [:botond]]

Attachment: Layer dump

Attached is a layer dump. Besides being suspiciously long, there are a number of places where the same scroll id occurs at three different levels in the layer tree (a layer, a child layer, and a grandchild layer); that's all kinds of wrong.

Comment 10

[Botond Ballo [:botond]]

We are planning to make some changes to FrameLayerBuilder in bug 1501342 which should hopefully eliminate a category of these bugs. Let's see if that fixes this too.

Comment 11

[Botond Ballo [:botond]]

This is indeed fixed by the patch in bug 1501342.

Comment 12

[Botond Ballo [:botond]]

Verified fixed in today's nightly.

Comment 13

[Botond Ballo [:botond]]

Setting flags as per bug 1501342.