Bug 135619

Summary: Opacity values are not clamped during transition causing elements with identical colors to become temporarily distinct
Product: WebKit Reporter: jseanxu
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: RESOLVED INVALID    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: Windows 8   
URL: http://jsfiddle.net/ETzZe/7/

Description jseanxu 2014-08-05 14:14:36 PDT
When putting a CSS transition the opacity property with a cubic-bezier curve that goes out of [0,1] range (i.e. [0,2,0,2]), changing opacity can cause the element flashes because opacity is not clamped.

Steps to Reproduce:
-Go to: http://jsfiddle.net/ETzZe/7/
-Hover over the box
-Notice the circle inside the box lighting up

Expected result:
Since both the circle and box have the same background-color, and the circle is just changing opacity, no visible change should have occurred.

Actual result:
The opacity of the circle is being transitioned on hover, the opacity value appears to temporarily go beyond 1.0 and the circle lights up.
Comment 1 jseanxu 2014-08-05 14:42:39 PDT
This appears to work fine on webkit Safari and only affects Chrome... marking as resolved.