1375012 - arrowscrollbox scroll buttons are intermittently rendered as disabled or enabled when they should have the opposite state

Status: NEW

(Toolkit :: UI Widgets, defect, P3)

Description

[Dão Gottwald [:dao]]

See bug 1368208 comment 56:

> I think I'll land this with 508816-1.xul disabled. The scroll buttons seem
> to suffer from some weird invalidation bug that I can reproduce even in
> nightly (e.g. in the all tabs list or in the bookmarks menu). My patch
> doesn't seem to make this worse but changes the timing such the reftest now
> exposes this bug.

I added some logging to _updateScrollButtonsDisabledState to see if it enables/disables the buttons as expected. It does do so, i.e. the buttons' disabled attributes get updated, but it seems that somehow this doesn't necessarily get rendered.

Comment 1

[:Paolo Amadini]

Attachment: Bug 1375012 - Wait for a layout flush in the reftest for "arrowscrollbox" scrolling.

Review commit: https://reviewboard.mozilla.org/r/248160/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/248160/

Comment 2

[:Paolo Amadini]

With the timing aligned, the test doesn't fail anymore in a tryserver run of 20 rebuilds on all platforms:

https://treeherder.mozilla.org/testview.html?repo=try&revision=1fe08c6d023035d382df88a2b4e08317c85ab53f

This can unblock bug 1457719, even though the reftest is still running unprivileged until bug 1465457 is fixed.

Comment 3

[Dão Gottwald [:dao]]

I'm still seeing what I wrote in comment 0, so I think we have a legitimate bug here, not just a test issue. If we can enable the test regardless, that's fine with me, but we'll still want to track the underlying issue I filed this bug for.

Comment 4

[:Paolo Amadini]

(In reply to Dão Gottwald [::dao] from comment #3)
> I'm still seeing what I wrote in comment 0, so I think we have a legitimate
> bug here, not just a test issue. If we can enable the test regardless,
> that's fine with me, but we'll still want to track the underlying issue I
> filed this bug for.

Sounds good, I cloned this to bug 1465730.

Comment 5

[:Paolo Amadini]

Comment on attachment 8982133 [details]
Bug 1375012 - Wait for a layout flush in the reftest for "arrowscrollbox" scrolling.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/248160/diff/1-2/

Comment 6

[:Paolo Amadini]

Comment on attachment 8982133 [details]
Bug 1375012 - Wait for a layout flush in the reftest for "arrowscrollbox" scrolling.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/248160/diff/2-3/