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about Microsoft test margin-collapse-030.htm and margin-collapse-029.htm

From: Bruno Fassino <fassino@gmail.com>
Date: Thu, 11 Feb 2010 07:41:25 +0100
Message-ID: <da98bce01002102241u104050e8h736763e2cf21710f@mail.gmail.com>
To: public-css-testsuite@w3.org
The assertions of :

http://www.w3.org/Style/CSS/Test/CSS2.1/20100127/html4/margin-collapse-029.htm
http://www.w3.org/Style/CSS/Test/CSS2.1/20100127/html4/margin-collapse-030.htm

are:

"When margins collapse through empty elements and the parent element
is not participating in margin collapsing then the position of the
elements top border should be in the same position as if the element
had a top border specified."

"When margins collapse through empty elements and only the parent
element's bottom margin is participating in margin collapsing then the
position of the elements top border should be in the same position as
if the element had a top border specified"



First: The spec (at 8.3.1) currently mentions the _bottom_ border and
not the _top_ one (this has changed from some previous version) :

"The position of the element's top border edge is the same as it would
have been if the element had a non-zero _bottom_ border.


Second and more important, I think these tests don't show anything
related to the assertion. In both of them there is an element div3
with its own margins collapsing, and collapsing with the margin-top of
a following sibling div4. But nothing can reveal the position of div3
top border.
The spec clearly says:

"Note that the positions of elements that have been collapsed through
have no effect on the positions of the other elements with whose
margins they are being collapsed; the top border edge position is only
required for laying out descendants of these elements."

So the only way to really check the position of a 'collapsed through'
element (like div3) is when it has some descendants, but there are
none in these tests.
In other words: The tests check that some collapsing works properly,
but do not really check the position of a 'collapsed through' element
as they claim.


Best regards,

Bruno

-- 
Bruno Fassino http://www.brunildo.org/test
Received on Thursday, 11 February 2010 06:41:59 GMT

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