1249750 - Content area occasionally goes blank when dragging scrollbar with APZ drag enabled

Status: RESOLVED WORKSFORME

(Core :: Panning and Zooming, defect)

Description

[Ryan VanderMeulen [:RyanVM]]

Unfortunately, this has been happening intermittently for me w/ APZ drag enabled, so I don't have reliable STR. It happens when I click the drag bar to start scrolling. What I do know is that the only way I've been able to get the content area to repaint is to open and close a new tab. Resizing the window doesn't seem to work.

Graphics
--------

Adapter Description: NVIDIA Quadro M1000M
Adapter Drivers: nvd3dumx,nvwgf2umx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um,nvwgf2um
Adapter RAM: 2048
Asynchronous Pan/Zoom: wheel input enabled; touch input enabled; scrollbar drag enabled
Device ID: 0x13b1
Direct2D Enabled: true
DirectWrite Enabled: true (10.0.10586.0)
Driver Date: 2-8-2016
Driver Version: 10.18.13.6191
GPU #2 Active: false
GPU Accelerated Windows: 2/2 Direct3D 11 (OMTC)
Subsys ID: 16d91028
Supports Hardware H264 Decoding: Yes
Vendor ID: 0x10de
WebGL Renderer: Google Inc. -- ANGLE (NVIDIA Quadro M1000M Direct3D11 vs_5_0 ps_5_0)
windowLayerManagerRemote: true
AzureCanvasBackend: direct2d 1.1
AzureContentBackend: direct2d 1.1
AzureFallbackCanvasBackend: cairo
AzureSkiaAccelerated: 0

Comment 1

[George K.]

I've seen something similar when scrolling via the mouse scroll wheel. In my case, all "foreground" content disappears, leaving only the page background (image or color).

Like comment #0, I have no STR as the issue seems to crop up randomly. It does seem like larger pages are more likely to exhibit the issue, but that may just be because they have more content to scroll past.

Unlike comment #0, I've been able to fix the painting by scrolling the page in the vast majority of, if not all, cases.

I just set apz.highlight_checkerboarded_areas to true to see if the blank content is actually checkerboarding.

I haven't yet seen that issue again since doing so (yet), but I have already noticed the entire content area of a lot of pages will often briefly flash red even while scrolling slowly, sometimes more than once in rapid succession. I'd previously noticed that pages tended to flicker slightly while scrolling, so I think something is causing previously-rendered page content to re-render while scrolling. No idea if that is related to this bug or perhaps even expected behavior.


Application Basics
------------------

Name: Firefox
Version: 47.0a2
Build ID: 20160321004046
Update Channel: aurora
User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0
OS: Windows_NT 6.1 x86-64
Multiprocess Windows: 15/15 (Enabled by user)
Safe Mode: false

Graphics
--------

Adapter Description: Intel(R) HD Graphics 3000
Adapter Drivers: igdumd64 igd10umd64 igd10umd64 igdumd32 igd10umd32 igd10umd32
Adapter RAM: Unknown
Asynchronous Pan/Zoom: wheel input enabled
Device ID: 0x0126
Direct2D Enabled: true
DirectWrite Enabled: true (6.2.9200.17568)
Driver Date: 5-26-2015
Driver Version: 9.17.10.4229
GPU #2 Active: false
GPU Accelerated Windows: 15/15 Direct3D 11 (OMTC)
Subsys ID: 21ce17aa
Supports Hardware H264 Decoding: Yes
Vendor ID: 0x8086
WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 3000 Direct3D11 vs_4_1 ps_4_1)
windowLayerManagerRemote: true
AzureCanvasAccelerated: 0
AzureCanvasBackend: direct2d 1.1
AzureContentBackend: direct2d 1.1
AzureFallbackCanvasBackend: cairo

Comment 2

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

Andy, what you reported (with mousewheel scrolling) sounds like it's probably the same as bug 1257491 (or bug 1258426, which is likely the same issue).

Comment 3

[George K.]

That's possible. It just happened to me again and I'd say calling the scrollable area "perma-checkerboarded" would be apt.

Was bug 1257491 flagged as "status-firefox47: unaffected" because APZ isn't being enabled in the release channel for 47?

Comment 4

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

No, it's marked unaffected on 47 because it's a regression from bug 1242609, which landed on 48. So bug 1257491 should not be affecting 47; if there are similar symptoms there then it's some other root cause.

Comment 5

[George K.]

I'm experiencing my scrolling "perma-checkerboard" issue on Aurora 47, so it's definitely not bug 1257491.

Should I open a new bug, since Ryan has to open and close tabs to clear his issue while I only have to scroll?

Comment 6

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

(In reply to Andy from comment #5)
> Should I open a new bug, since Ryan has to open and close tabs to clear his
> issue while I only have to scroll?

Yes, please.

Comment 7

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

I'm going to take off the affected flags because APZ drag is not enabled by default.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

I haven't seen this in ages.