1410784 - stylo: scrollbar doesn't show on layout/reftests/bugs/558011-1.xul

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, defect, P3)

Comment 1

[Xidorn Quan [:xidorn] UTC+10]

...???

The <xul:scrollbox> element inside the <richlistbox> in this test has a style attribute "overflow: auto", however it is overridden by some rule and its computed value is "hidden".

If I change the style attribute to "overflow: auto !important", it would generate the scrollbar as expected.

Comment 2

[Xidorn Quan [:xidorn] UTC+10]

Taking for now. Will investigate further tomorrow.

Comment 3

[Xidorn Quan [:xidorn] UTC+10]

It's unrelated to !important. The style attribute is not cascaded at all regardless of !important. If I change the property in the inspector, it gets re-cascaded and thus scrollbar shows up.

Comment 4

[Xidorn Quan [:xidorn] UTC+10]

So what's happening here is that, we get a Gecko declaration block for that style attribute.

This happens because the style attribute is inside a XBL binding, and the binding itself has system principal, so the workaround code added in bug 1408235 doesn't help in this case.

I don't have a clear idea how this should be fixed. Maybe we can ignore this for now, and wait for enabling stylo on chrome, at which point this failure should go away directly.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

So the specific styloVsGecko reftest wouldn't get fixed even after we enable stylo-chrome, because when we do so, we would get the scrollbar with Servo backend, but not with Gecko backend. We would always have backend mismatch on one side or the other, but as far as the scrollbar is shown correctly, I guess it isn't a big deal.

Comment 6

[Xidorn Quan [:xidorn] UTC+10]

So this is a styloVsGecko-only issue exposed because it mixes different style system.

Given that we are removing the old style system, and stylo is becoming the only one, I'm going to just close it as WONTFIX.