Bug 217850

Summary: [WinCairo] sluggish page scrolling for wheel events since r268499
Product: WebKit Reporter: Fujii Hironori <Hironori.Fujii>
Component: ScrollingAssignee: Fujii Hironori <Hironori.Fujii>
Status: RESOLVED FIXED    
Severity: Normal CC: simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch none

Description Fujii Hironori 2020-10-16 15:20:57 PDT 
[WinCairo] sluggish page scrolling even in non-AC mode

1. Start WinCairo MiniBrowser
2. Go to https://trac.webkit.org/wiki
3. scroll down by mouse wheel

r267199 (with WebKitRequirements v2020.08.20): smooth scrolling
r268564 (with WebKitRequirements v2020.10.04): sluggish scrolling
Comment 1 Simon Fraser (smfr) 2020-10-16 19:44:59 PDT 
Test around r268287, r268417, r268476, r268499.
Comment 2 Fujii Hironori 2020-10-18 13:08:56 PDT 
It's a very useful information for bisecting. Thank you.

r268498 : smooth scrolling
r268499 : sluggish scrolling

This issue has been started since r268499.
Comment 3 Fujii Hironori 2020-10-18 13:58:05 PDT 
Created attachment 411718 [details]
Patch
Comment 4 Fujii Hironori 2020-10-18 13:59:05 PDT 
I don't understand this change, but I confirmed this patch fixes the WinCairo issue.
Comment 5 Fujii Hironori 2020-10-18 22:18:43 PDT 
Comment on attachment 411718 [details]
Patch

Clearing flags on attachment: 411718

Committed r268664: <https://trac.webkit.org/changeset/268664>
Comment 6 Fujii Hironori 2020-10-18 22:18:46 PDT 
All reviewed patches have been landed.  Closing bug.
Comment 7 Radar WebKit Bug Importer 2020-10-18 22:19:18 PDT 
<rdar://problem/70427879>