950414 - Scrolling SDK panel messes up content display in Firefox 26 on Windows

Status: RESOLVED WONTFIX

(Add-on SDK Graveyard :: General, defect)

Description

[Mingyi Liu]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0 (Beta/Release)
Build ID: 20131205075310

Steps to reproduce:

In my addon, I have an iframe inside an SDK panel. I set the iframe to be 800x200 and the content is about 1000x5000 or so. So there are scrollbars displayed for the iframe naturally.  The issue happens when user starts to scroll the iframe scrollbars


Actual results:

Sometimes the content displayed is the content beneath the panel (meaning the iframe and panel became transparent AND the iframe content wasn't displayed). As I found, if I set iframe big enough such that the iframe doesn't have scrollbars but the panel does, scrolling the panel scrollbar will lead to the same problem! So this is not really iframe issue, it's a panel issue.  Note that I've tested the issue on Linux and Win7 and Win8, and Linux worked fine. Only FF26 on Win7/Wiin8 displayed this issue (FF25 worked fine either on Linux or Windows).  Note that if you wait a few seconds, the content of the iframe/panel will actually then show up.


Expected results:

Scrolling scrollbars should not mess with panel/iframe content display.

Comment 1

[Mingyi Liu]

BTW please fix it quick if possible - this renders the SDK panel with large content practically unusable for Windows users of FF26. And it's not the only panel bug I found and filed for FF26.  Panels for FF25 and older all worked without issues.

Comment 2

[cytior]

I have the same kind of problem. My addon is built with the SDK 1.14 and there are scroll issues in FF26. The scrolled part of the panel seems to have rendering lag, with some images showing after 3-4s when you scroll up&down. Once Hardware Acceleration is disabled, everything works fine.

The easy way would be to disable Hardware Acceleration with the addon, but I don't want to force that...

Comment 3

[Mingyi Liu]

I will double check on Hardware Acceleration, but my feeling is that it's more serious than that in FF26. My addon, over years of usage, two or three users had complained seeing blank content in SDK panels. Turned out it's the Hardware Acceleration + specific computers (fine on most computers).

However, in those cases, it's the entire panel being blank, unrelated to scrolling. Moreover, I'm almost certain that some of my Windows computers do not have Hardware Acceleration enabled (I will double check) and I began to see this scrolling issue ONLY after I updated FF25 to FF26.

Before I filed this bug, I actually checked and saw the computer I was filing the bug on had Hardware Acceleration enabled. So I turned it off and still saw the scrolling issue. However, I might not have restarted Firefox after the setting change, therefore I'll do double checking on that too.

Regardless, even if the scrolling issue is due to Hardware Acceleration, it's at least a much more serious issue than before - as I said, before over years only 2-3 users complained Hardware Acceleration messed up their panels, but now in FF26 EVERY Windows computer (didn't check XP but certainly 7 and 8 both suffer) has the scrolling issue for the SDK Panels.

Comment 4

[cytior]

I've checked on the Beta version (27.0) and the problem seems fixed. There is no indication in the changelogs of FF26 or FF27 indicating they have changed something about scroll or panels, so I don't know if the bug is already known or fixed by coincidence/side effect.

Comment 5

[Mingyi Liu]

Yes, you're right. Disabling Hardware Acceleration did fix the issue (I probably forgot to restart FF after changing that option yesterday) for all my Windows computers (WinXP, Win7 and Win8). I'll check FF27b later, and will test Linux and see if it also would have the issue with Hardware Acceleration enabled.

Comment 6

[cytior]

I've checked on Mac OS X Moutain Lion with FF26 and Hardware Acceleration enabled, and it works fine.

Comment 7

[Mingyi Liu]

Yes, I confirm that FF27b seemed working fine for panels on my Win8. Also my Linux in virtualbox on a Win7 machine worked fine for panels even in FF26. So basically for the same hardware, if OS is Windows, FF26 messes up panels; but if OS is Linux, panels work fine.

Comment 8

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

If this is fixed in 27, I'm not sure what we can do about this.