Re: [css3-background] does border-radius round the border-image ?

On Jan 10, 2009, at 10:15 PM, Brad Kemper wrote:
> I did some test cases and saw how they rendered in a recent WebKit  
> nightly and Firefox 3.2 nightly. I used 'background-clip:padding- 
> box;', which shows the importance of not clipping the border-image  
> based on the border-radius (at least not to do so in that situation,  
> IMO, but I believe its the same problem with default background- 
> clip, just not as obvious).:
>
> http://www.bradclicks.com/cssplay/BorderImageAndRadius.html

I think there's just a different interpretation of the spec, here. To  
me, using background-clip: padding;  would presumably render the  
background to content+padding box, clipped only by the external radius  
of any possibly-applied border-radius. This is what WebKit does.

What you're expecting, however, seems to be that the background should  
be clipped to the inner circle of the border-radius, in this case  
severely impeding on the boundaries of the padding box. Or really I  
should say, largely not even reaching the boundaries of the padding  
box. This is what Firefox does.

I don't think either browser is right or wrong, I think the spec is  
inconclusive as to what the behavior should be like. I can see  
arguments for both interpretations, but I'm personally inclined to  
side with WebKit's implementation simply because the padding of the  
box (and the content box itself) don't get their foreground dimensions  
curved, i.e. the text is still in a rectangular box, and the padding  
around the text is still a rectangular box as well.

Perhaps an expansion to the spec here would be useful, as I can see  
reason for both scenarios to co-exist rather than one being dropped in  
favor of the other.

Faruk