Jim Avera Reporter
	Description • 9 years ago

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0
Build ID: 20150511103303

Steps to reproduce:

Visit https://www.mageia.org/en/about/2010-sept-announcement.html#people
and scroll through the list of people (there will be two scroll-bars: One for the whole page, which is very long, and a second "inner" scroll bar for the list of people).



Actual results:

While scrolling in the list, lines will suddenly elongate vertically to consume most of the list viewport, then collapse back to normal as the scroll progresses.

===> Please see the attached screen-shot


Expected results:

Lines should scroll by normally without being periodically blown up to huge height.

	Jim Avera Reporter
	Comment 1 • 9 years ago

Update: The bug seems to occur only when you first start at the top of the page and then scroll down to the "People" section with the mouse wheel (not by manipulating the scroll bar directly).  THEN grab the inner-most scroll bar to scroll the list of people, and the rendering problem happens.

Please start by visiting https://www.mageia.org/en/about/2010-sept-announcement.html
(without the #people id suffix given in the original post) and use the scroll-wheel to bring the "People" section into view.

	Alice0775 White
	Comment 2 • 9 years ago

[Tracking Requested - why for this release]: Rendering problem on ESR38 on Ubuntu14.04

	Alice0775 White
	Comment 3 • 9 years ago

Graphics of the version with the defect

Graphics
--------

Adapter Description: VMware, Inc. -- Gallium 0.4 on SVGA3D; build: RELEASE;
Asynchronous Pan/Zoom: none
Device ID: Gallium 0.4 on SVGA3D; build: RELEASE;
Driver Version: 2.1 Mesa 10.1.3
GPU Accelerated Windows: 0/1 Basic (OMTC)
Supports Hardware H264 Decoding: false
Vendor ID: VMware, Inc.
WebGL Renderer: VMware, Inc. -- Gallium 0.4 on SVGA3D; build: RELEASE;
windowLayerManagerRemote: true
AzureCanvasBackend: cairo
AzureContentBackend: cairo
AzureFallbackCanvasBackend: none
AzureSkiaAccelerated: 0

	Alice0775 White
	Comment 4 • 9 years ago

This have been broken since Firefox34 at least.


And was fixed in cycle of Nightly40.
Fixed range
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=4d6d69f0f499&tochange=d0fc7202b4cb

	Nicolas Silva [:nical]
	Comment 5 • 9 years ago

Markus, looks like one of your patches fixed the issue, do you think you could identify which part and if it is worth uplifting ?

	Markus Stange [:mstange] Assignee
	Comment 6 • 9 years ago

All those patches need to land together, and they're way too risky to uplift. Moreover, this is not the kind of bug they should have fixed; they might have jiggled things around so that we don't hit the code path with the bug, so the real bug will probably still exist somewhere. (For example, those patches made us use opaque layers where we were using transparent layers before in some cases, and the reverse.)

I'll see whether I can reproduce the problem under rr (or whether it's an xrender bug).

	Markus Stange [:mstange] Assignee
	Comment 7 • 9 years ago

This reproduces under rr. :-)

	Sylvestre Ledru [:Sylvestre]
	Comment 8 • 9 years ago

[Tracking Requested - why for this release]:
Clearly not a driver for a 38 dot releases.
If we have a safe patch, why not uplifting it to 39.

ESR sounds unlikely as we have this bug since Fx 34.

	jen strickland :jenstrickland
	Comment 9 • 9 years ago

Tracked for 39. We're about to ship beta 3, but this could ship in beta 4, if you land a patch.

	Markus Stange [:mstange] Assignee
	Comment 10 • 9 years ago

(In reply to Alice0775 White from comment #3)
> Graphics of the version with the defect
> 
> Graphics
> --------
> 
> Adapter Description: VMware, Inc. -- Gallium 0.4 on SVGA3D; build: RELEASE;
> Asynchronous Pan/Zoom: none
> Device ID: Gallium 0.4 on SVGA3D; build: RELEASE;
> Driver Version: 2.1 Mesa 10.1.3
> GPU Accelerated Windows: 0/1 Basic (OMTC)

The OMTC part here confuses me. Alice, can you confirm that this bug is really reproducible in a build that uses OMTC? I've only been able to reproduce it without OMTC, and in most builds I've tried, setting layers.offmainthreadcomposition.enabled to true didn't even cause OMTC to be turned on.

	Markus Stange [:mstange] Assignee
	Comment 11 • 9 years ago

Bug 1169331 - Always clip rotated buffer quadrant drawing to the fill rect. r?jrmuizel

	Alice0775 White
	Comment 12 • 9 years ago

(In reply to Markus Stange [:mstange] from comment #10)
> (In reply to Alice0775 White from comment #3)
> > Graphics of the version with the defect
> > 
> > Graphics
> > --------
> > 
> > Adapter Description: VMware, Inc. -- Gallium 0.4 on SVGA3D; build: RELEASE;
> > Asynchronous Pan/Zoom: none
> > Device ID: Gallium 0.4 on SVGA3D; build: RELEASE;
> > Driver Version: 2.1 Mesa 10.1.3
> > GPU Accelerated Windows: 0/1 Basic (OMTC)
> 
> The OMTC part here confuses me. Alice, can you confirm that this bug is
> really reproducible in a build that uses OMTC? I've only been able to
> reproduce it without OMTC, and in most builds I've tried, setting
> layers.offmainthreadcomposition.enabled to true didn't even cause OMTC to be
> turned on.

My bad, reproduced w/o OMTC.

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 13 • 9 years ago

Markus is this ready to land ? Or are you still working on it? Thanks.

	Markus Stange [:mstange] Assignee
	Comment 14 • 9 years ago

https://treeherder.mozilla.org/#/jobs?repo=try&revision=74d2ace18c62

	Markus Stange [:mstange] Assignee
	Comment 15 • 9 years ago

Just need to wait for the tryserver results, then I'll land it.

	Markus Stange [:mstange] Assignee
	Comment 16 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/67527d8c0688

	Ryan VanderMeulen [:RyanVM]
	Comment 17 • 9 years ago

Backed out for being the most-likely cause of semi-frequent Android debug reftest failures like the log shown below:
https://treeherder.mozilla.org/logviewer.html#?job_id=10679939&repo=mozilla-inbound

https://hg.mozilla.org/integration/mozilla-inbound/rev/99d6da0042f3

	Markus Stange [:mstange] Assignee
	Comment 18 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/a490322a1877

	Markus Stange [:mstange] Assignee
	Comment 19 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/b9562bd4954b

	Markus Stange [:mstange] Assignee
	Comment 20 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/cf373ad45129

	Carsten Book [:Tomcat]
	Comment 21 • 9 years ago

https://hg.mozilla.org/mozilla-central/rev/a490322a1877
https://hg.mozilla.org/mozilla-central/rev/b9562bd4954b
https://hg.mozilla.org/mozilla-central/rev/cf373ad45129

	Markus Stange [:mstange] Assignee
	Comment 22 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/df1354cdd7fb

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 23 • 9 years ago

Markus or Jeff, do you want to request uplift for this at least to aurora? May be a bit late for beta unless you think it is super important not to ship this with 39 and you can verify it works on nightly.

	Ryan VanderMeulen [:RyanVM]
	Comment 24 • 9 years ago

https://hg.mozilla.org/mozilla-central/rev/df1354cdd7fb

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 25 • 9 years ago

Just realized aurora is unaffected. Wontfix for 39 since at this point we are pretty focused on stability and security fixes.