Bug 113051

Summary: Flexbox can cause big paint in some circumstances
Product: WebKit Reporter: David Håsäther <hasather+webkitbugs>
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: RESOLVED CONFIGURATION CHANGED    
Severity: Normal CC: bfulgham
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Mac (Intel)   
OS: OS X 10.8   
Attachments:
Description Flags
Demo of the bug none

Description David Håsäther 2013-03-22 06:12:42 PDT 
In some circumstances, an absolutely positioned element with `display: flexbox` will cause a large paint (bottom right position of the element to the top left position of the viewport in Chrome, less in Safari, but still a larger area than the element itself).

Attaching a testcase which is about as minimal as I could get it. To verify, open Web Inspector and use "Show paint rectangles" (or the Timeline), and hover the element that says "Hover". (The existence of opacity also seems to influence this, I don't see the same thing if I only change the background-color on hover for example.)
Comment 1 David Håsäther 2013-03-22 06:13:17 PDT 
Created attachment 194528 [details]
Demo of the bug
Comment 2 Brent Fulgham 2022-07-13 14:25:40 PDT 
Safari, Chrome, and Firefox all agree on rendering for this test case. I don't believe there is any remaining compatibility issue.