962881 - Regression in Scrolling in the Email App w/ APZ on

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect, P1)

Description

[Mason Chang [Inactive] [:mchang]]

Attachment: adb logcat while scrolling

Scrolling in the Email app has no inertial scrolling with the latest gecko revision. This is a regression in Gecko. This affects all parts of the email app, including scrolling through folders. This doesn't seem to effect any other gaia app. 

Details:
1) APZ + HWC is enabled.
2) Gaia Rev - 2162b4a, v1.3 b1e8602 - Occurs on both.

Good Gecko Rev:
changeset:   164407:d8f0dc811109
tag:         tip
user:        Richard Newman <[e-mail]>
date:        Tue Jan 21 08:23:43 2014 -0800
summary:     No bug: the OVERRIDE HOOK is stupid.

Bad Gecko Rev:
changeset:   164725:cad591993bfa
tag:         tip
parent:      164702:66bd9fa91eff
parent:      164724:385ed622a7da
user:        Ryan VanderMeulen <[e-mail]>
date:        Wed Jan 22 15:32:22 2014 -0500
summary:     Merge fx-team to m-c.

Comment 1

[Mason Chang [Inactive] [:mchang]]

Attachment: Video of Scrolling

Comment 2

[Andreas Gal :gal]

Doug might be able to help with this.

Comment 3

[Mason Chang [Inactive] [:mchang]]

Started bisecting. Thanks for the contact @gal.

Doug, if you have any thoughts on what changed in the past day, I'd appreciate it. Thanks!

Comment 4

[Mason Chang [Inactive] [:mchang]]

Just finished bisecting, the bad commit is:

changeset:   164587:28f8657d36e9
user:        Benoit Girard <[e-mail]>
date:        Tue Jan 21 12:33:52 2014 -0500
summary:     Bug 950488 - Overhaul APZ handling of overflow:hidden. r=botond


Benwa: Is it possible to change a few email CSS properties or do we need to back the change out? Thanks!

Comment 5

[Doug Sherk (:drs) (inactive)]

I've traced the problem to here:
http://mxr.mozilla.org/mozilla-central/source/gfx/layers/ipc/Axis.cpp#140

I'm not sure yet why we're getting axis locked on a regular scrollable frame. Looking more into it.

Comment 6

[Doug Sherk (:drs) (inactive)]

I've traced it further to here:
http://mxr.mozilla.org/mozilla-central/source/gfx/layers/ipc/Axis.cpp#145

And then to here:
http://mxr.mozilla.org/mozilla-central/source/layout/base/nsDisplayList.cpp#625

It seems that the scrollbar styles are being misreported, or something like that. Here's the relevant code in Gaia:
https://github.com/mozilla-b2g/gaia/blob/9fba58cd97022041dd804961c8587a8f45950e63/apps/email/style/message_cards.css#L9

Commenting out this line fixes the issue O.o

Comment 7

[Botond Ballo [:botond]]

(In reply to Mason Chang [:mchang] from comment #4)
> Just finished bisecting, the bad commit is:
> 
> changeset:   164587:28f8657d36e9
> user:        Benoit Girard <[e-mail]>
> date:        Tue Jan 21 12:33:52 2014 -0500
> summary:     Bug 950488 - Overhaul APZ handling of overflow:hidden. r=botond
> 
> 
> Benwa: Is it possible to change a few email CSS properties or do we need to
> back the change out? Thanks!

There is a bug in this patch: on this line [1], we are passing a flag that pertains to the x axis, to a function that deals with the y axis. In this case the element is overflow-x:hidden, and this is preventing the y axis from scrolling.

[1] http://mxr.mozilla.org/mozilla-central/source/gfx/layers/ipc/AsyncPanZoomController.cpp#1231

Comment 8

[Benoit Girard (:BenWa)]

Attachment: Fix typo

Comment 9

[Benoit Girard (:BenWa)]

Actually assigning back to mchang since he did all the heavy lifting here :)

Comment 10

[Benoit Girard (:BenWa)]

Patch is in my outgoing queue but tree is closed.

Comment 11

[Benoit Girard (:BenWa)]

https://hg.mozilla.org/integration/b2g-inbound/rev/c2029fa25945

Comment 12

[Kartikaya Gupta (email:[e-mail])]

This will need uplifting to aurora as well.

Comment 14

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/c2029fa25945

Comment 15

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/573b19cdae30

Comment 16

[Benoit Girard (:BenWa)]

(In reply to Ryan VanderMeulen [:RyanVM UTC-5] from comment #15)
> https://hg.mozilla.org/releases/mozilla-aurora/rev/573b19cdae30

Thanks for uplifting this and the previous bug Ryan :)

Comment 17

[Liz Henry (:lizzard) (relman/hg->git project)]

kevin, is this something you could verify or pass on to someone who's set up for FirefoxOS testing? Thanks!