Bug 225467 - REGRESSION (Safari 14): Submenus on https://codelearn.cat don't show
Summary: REGRESSION (Safari 14): Submenus on https://codelearn.cat don't show
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari Technology Preview
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Simon Fraser (smfr)
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2021-05-06 09:59 PDT by Simon Fraser (smfr)
Modified: 2021-06-22 11:33 PDT (History)
12 users (show)

See Also:

Attachments
Patch (5.99 KB, patch)
2021-06-09 10:55 PDT, Simon Fraser (smfr) 		no flags Details | Formatted Diff | Diff
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Description Simon Fraser (smfr) 2021-05-06 09:59:29 PDT 
Hover the menus on https://codelearn.cat: hover "Centres" then "Barcelona" and the hover menus fail to appear.

To reproduce, your window needs to be short enough for the longer menus to scroll.
Comment 1 Radar WebKit Bug Importer 2021-05-06 10:00:21 PDT 
<rdar://problem/77612276>
Comment 2 Simon Fraser (smfr) 2021-05-06 10:00:32 PDT 
Probably related to async overflow scroll and compositing.
Comment 3 Simon Fraser (smfr) 2021-06-08 14:20:37 PDT 
This might be fallout from the RenderLayer/ScrollableArea split.

There's a composited layer with overflow:scroll, and overflow is being toggled to 'visible'. We fail to remove the compositing clipping layer, so the content remains clipped.

This is happening because RenderBox::requiresLayerWithScrollableArea() is called from RenderLayer::styleChanged() (i.e. before layout) but it consults hasHorizontalOverflow() || hasVerticalOverflow() which depend on layout.
Comment 4 Simon Fraser (smfr) 2021-06-08 14:21:03 PDT 
We also never remove the RenderLayerScrollableArea and it seems like we should.
Comment 5 Simon Fraser (smfr) 2021-06-09 10:55:29 PDT 
Created attachment 430979 [details]
Patch
Comment 6 EWS 2021-06-22 11:33:32 PDT 
Committed r279130 (239044@main): <https://commits.webkit.org/239044@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 430979 [details].