Bug 249869

Summary:	Fix missing invalidation when scrollbar is destroyed
Product:	WebKit	Reporter:	Ahmad Saleem <ahmad.saleem792>
Component:	Scrolling	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	karlcow, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari Technology Preview
Hardware:	Unspecified
OS:	Unspecified

Description Ahmad Saleem 2022-12-24 07:48:25 PST

Hi Team,

I don't know whether this is needed or it will fix any issue but following is Blink commit:

Blink Commit - https://chromium.googlesource.com/chromium/blink/+/f3a2b99c3c2ee5d435c09ceedcd4a1f213c3baf7

WebKit Source - https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderLayerScrollableArea.cpp#910 & https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderLayerScrollableArea.cpp#936

Just wanted to raise, if this is needed or not.

Thanks!

Comment 1 Radar WebKit Bug Importer 2022-12-31 07:49:15 PST

<rdar://problem/103790698>

Comment 2 Ahmad Saleem 2023-10-11 03:11:49 PDT

Repaint Rects (pre-this change):

Tests invalidation when a scrollbar is destroyed. Passes if there is no scrollbar.
 (repaint rects
  (rect 0 100 100 200)
  (rect 0 100 100 100)
  (rect 0 100 200 200)
  (rect 0 100 200 200)
)


and post this change:

Tests invalidation when a scrollbar is destroyed. Passes if there is no scrollbar.
 (repaint rects
  (rect 0 100 100 200)
  (rect 0 100 100 100)
  (rect 185 100 15 200)
  (rect 0 100 200 200)
  (rect 0 100 200 200)
)

____

Now we have an additional 'rect'.

Comment 3 Ahmad Saleem 2023-12-20 19:30:26 PST

PR Attempt for future reference - https://github.com/WebKit/WebKit/pull/19001