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[css3-cascade] Unexpected computed value when cascaded value is 'inherit'

From: Anton Prowse <prowse@moonhenge.net>
Date: Mon, 14 Jan 2013 21:39:01 +0100
Message-ID: <50F46CE5.4000504@moonhenge.net>
To: "www-style@w3.org" <www-style@w3.org>
The css3-cascade WD of 2013-01-03 says, in 4.3.2:

   # The inherited value of a property on an [non-root] element is the
   # computed value of the property on the element's parent element.

   # If the cascaded value of a property is the ‘inherit’ keyword, the
   # inherited value becomes the property's /specified/ and computed
   # values.

Firstly, given that Section 4.3 is describing how to determine the 
specified value, I don't know why "specified" is emphasized; it confused 
me somewhat!  I think the word "and" should be emphasized instead, since 
the unexpected piece of information in that sentence is that the 
computed value is also influenced.

Secondly, I don't know why the computed value is influenced.  On the one 
hand, it's clearly wrong:

parent {display: inline}
child {display: inherit; float:left}

The computed value of 'display' for the child element is 'block', not 
the inherited value ('inline').

On the other hand, it seems such intentional wording that it makes me 
wonder what other situation can arise that requires us to explicitly 
spec the computed value rather than just let it be determined from the 
specified value (which is already an valid computed value).  In other 
words, the editors obviously believe there is a situation in which the 
normal process of converting a specified value x to a computed value y 
yields x != y despite x being a valid computed value.  I can't think of 
such a situation off the top of my head.


Cheers,
Anton Prowse
http://dev.moonhenge.net
Received on Monday, 14 January 2013 20:39:26 GMT

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