[css21] Clarifications on errata item s.11.1.1b (overflow on tables)

I'm looking at testing this errata item for CSS 2.1:

[[
[2013-07-15] In 11.1.1 “Overflow: the 'overflow' property,” change the  
definition of 'scroll' and 'auto':

scroll
This value indicates that the content is clipped and that if the user  
agent uses a scrolling mechanism that is visible on the screen (such as a  
scroll bar or a panner), that mechanism should be displayed for a box  
whether or not any of its content is clipped. This avoids any problem with  
scrollbars appearing and disappearing in a dynamic environment. When this  
value is specified and the target medium is 'print', overflowing content  
may be printed. When used on table boxes, this value has the same meaning  
as 'visible'.
auto
The behavior of the 'auto' value is user agent-dependent, but should cause  
a scrolling mechanism to be provided for overflowing boxes. When used on  
table boxes, this value has the same meaning as 'visible'.
(See CSS WG minutes 2012-08-08.)
]]
http://www.w3.org/Style/css2-updates/REC-CSS2-20110607-errata.html#s.11.1.1b

The minutes say
[[
    - RESOLVED: Errata CSS2.1 to say that 'overflow' on a table element
                applies to the table box (not table wrapper box); and
                that values other than 'hidden' are treated as 'visible'.
]]
http://lists.w3.org/Archives/Public/www-style/2012Aug/0298.html

The errata don't seem to cover the part "'overflow' on a table element  
applies to the table box (not table wrapper box)", as far as I can tell.

Another issue that this change introduces is: what should happen when the  
root element is a table? Should overflow apply to the viewport, or the  
table box, or both? Similarly when HTML <body> is display:table.

For reference, the spec currently says about overflow on root/<body>:
[[
UAs must apply the 'overflow' property set on the root element to the  
viewport. When the root element is an HTML "HTML" element or an XHTML  
"html" element, and that element has an HTML "BODY" element or an XHTML  
"body" element as a child, user agents must instead apply the 'overflow'  
property from the first such child element to the viewport, if the value  
on the root element is 'visible'. The 'visible' value when used for the  
viewport must be interpreted as 'auto'. The element from which the value  
is propagated must have a used value for 'overflow' of 'visible'.
]]
http://www.w3.org/TR/2011/REC-CSS2-20110607/visufx.html#propdef-overflow

-- 
Simon Pieters
Opera Software

Received on Sunday, 10 November 2013 09:39:18 UTC