Bug 225467

Summary: REGRESSION (Safari 14): Submenus on https://codelearn.cat don't show
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, changseok, esprehn+autocc, ews-watchlist, glenn, kondapallykalyan, ntim, pdr, simon.fraser, webkit-bug-importer, zalan, zimmermann
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch none

Simon Fraser (smfr)
Reported 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.
Attachments
Patch (5.99 KB, patch)
2021-06-09 10:55 PDT, Simon Fraser (smfr) 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2021-05-06 10:00:21 PDT
<rdar://problem/77612276>
Simon Fraser (smfr)
Comment 2 2021-05-06 10:00:32 PDT
Probably related to async overflow scroll and compositing.
Simon Fraser (smfr)
Comment 3 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.
Simon Fraser (smfr)
Comment 4 2021-06-08 14:21:03 PDT
We also never remove the RenderLayerScrollableArea and it seems like we should.
Simon Fraser (smfr)
Comment 5 2021-06-09 10:55:29 PDT
Created attachment 430979 [details] Patch
EWS
Comment 6 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].
Note You need to log in before you can comment on or make changes to this bug.