[css3-animations] Possible spec bug?

Check this out: http://jsfiddle.net/leaverou/jwHva/2/

If you remove border-style: solid; from the div {...} rule, the 
animation stops having a visible effect, even though both the 
interpolated values contain border-style:solid; (in the shorthand). This 
doesn't change even with animation-fill-mode: both; It happens in both 
Webkit and Mozilla, so it's probably not a browser bug.

I discussed it with David Baron on IRC and his explanation was this:
dbaron: I think it may be because each property in the animation gets 
handled separately
dbaron: on top of the base values
dbaron: and with a 'none' border style the border-width doesn't do anything
leaverou: but I defined border-style in the animation, through the shorthand
dbaron: I doubt the spec is clear on this point, though.
dbaron: yeah
dbaron: my guess (haven't checked yet)
dbaron: is that despite that, the border-width computes to zero in the 
animation

I took a look at the spec, but couldn't find anything relevant.
I think it's very confusing behavior and potentially a spec bug, so 
thought I'd let you guys know.

-- 
Lea Verou (http://leaverou.me | @LeaVerou)

Received on Saturday, 29 October 2011 21:03:29 UTC