1024152 - Transformed elements "jumping around"

Status: NEW

(Core :: Layout, defect)

Description

[Patrick Storz]

Attachment: testcase showing the bug (move mouse cursor around over the icons)

The bug is apparent in the testcase attached:

Various images contained in a <span> with style "transform: scale(0.9);" set and an opacity changing on hovering applied start to "jumb around" on hovering instead of staying static and just changing opacity as intended.

The bug was already present in Firefox 28 (an probably earlier versions)
There was a severe regression in Firefox 29 (much more jumping)
In Firefox 30 the regression was fixed but the bug is comparable to FF 28

Comment 1

[Patrick Storz]

Possibly related: bug 757870 and bug 860261.

Also visible in attachment 8550808 [details] (testcase for bug 1122885).

Comment 2

[Julien Wajsberg [:julienw]]

I still reproduce in latest nightly (46 from 20160104030217) on Linux/GTK3. This is especially visible on the 3rd icon. This is likely a rounding issue but this is quite weird that we don't render the image in the same way...

Comment 3

[Julien Wajsberg [:julienw]]

Especially we don't have any animation/transition here.