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[CSS2.1] collapsing margins min or max height

From: Alan Gresley <alan@css-class.com>
Date: Tue, 21 Sep 2010 22:21:58 +1000
Message-ID: <4C98A366.6080508@css-class.com>
To: fantasai <fantasai.lists@inkedblade.net>
CC: "www-style@w3.org" <www-style@w3.org>
Was : [CSSWG] Minutes and Resolutions 2010-09-08
>   plinss: Issue 159.
[snip]
>   dbaron: There's a bullet point about "bottom margin of element and bottom
>           margin of last in-flow child" and the one after that - the
>           problem with those two is that they change the latter changes
>           the conditions of the former in the situation where all the
>           margins collapse with each other.
>   fantasai: I don't understand.
>   dbaron: The question is, does the bottom margin of a last child collapse
>           with the bottom margin of its parent?
>   dbaron: In particular, the case where the parent has non-zero min-height,
>           but auto height.


Gecko is the only impls that does not collapse the bottom margin of a 
child when the parent's (of auto height) min-height exceeds the used 
height of the child. All other impls collapses the bottom margins 
regardless of the min-height of the parent. This came up as  CSS2.1 
issue 79 back in 2008,

<http://lists.w3.org/Archives/Public/www-style/2008Nov/0109.html>

from this message.

<http://lists.w3.org/Archives/Public/www-style/2008Sep/0081.html>


I believe the current behavior as seen in Gecko is what is suggested 
by the prose in the text. Neither bottom margins in example 3 or 4 in 
this test case are adjoining.

<http://css-class.com/test/css/box/margins/collapsing-with-min-height.htm>

Same here where Gecko that does not collapse the bottom margin of a 
child when the parent's min-height exceeds the used height of the child.

<http://www.brunildo.org/test/collminmax.html>




-- 
Alan http://css-class.com/

Armies Cannot Stop An Idea Whose Time Has Come. - Victor Hugo
Received on Tuesday, 21 September 2010 12:22:37 GMT

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