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Re: [RC3] blocks-017 inaccurate height of wrapping div

From: Øyvind Stenhaug <oyvinds@opera.com>
Date: Fri, 12 Nov 2010 14:33:00 +0100
To: Gérard Talbot <css21testsuite@gtalbot.org>
Cc: "public-css-testsuite@w3.org" <public-css-testsuite@w3.org>
Message-ID: <op.vl17w9wcbunlto@oyvinds-desktop>
On Thu, 11 Nov 2010 22:11:52 +0100, Gérard Talbot  
<css21testsuite@gtalbot.org> wrote:

> Le Jeu 11 novembre 2010 4:22, Øyvind Stenhaug a écrit :
>> On Wed, 10 Nov 2010 20:37:54 +0100, Gérard Talbot
>> <css21testsuite@gtalbot.org> wrote:
>>> 2- for reasons I do not understand, Opera 10.63 and Firefox 3.6.12
>>> ignore the border-top-width and border-bottom-width around the 2
>>> tables
>>> in the tables' offsetHeight. Instead of returning 22px for the
>>> offsetHeight, they return 20px for the 2 tables.
>>
>> They have "(-moz-)box-sizing: border-box" in their UA stylesheet.
>> Relevant
>> quote from CSS2.1 17.6.1:
>>
>> "However, in HTML and XHTML1, the width of the <table> element is the
>> distance from the left border edge to the right border edge.
>
>
> This is for width of the anonymous box and it is repeated in section
> 17.4 ("(...) The width of the anonymous box is the border-edge width of
> the table box inside it (...).") [1].

Regardless, the box-sizing property applies for both width and height.

> The 2 tables have height: auto, not any specified height. The height of
> table box (element content box) with its borders (border belt, border
> area) should be rendered distinctively regardless of type of box-sizing
> triggered. As it is, border-top-width and border-bottom-width are
> substracted from the height of table box (or they are merged with the
> height of table box): clientHeight of those table elements, even in
> Opera 10.63, is 18px, not 20px.

First of all, I can only make a limited amount of sense out of the table  
chapter, but all the browsers I have here include borders as part of the  
<table> height.

Second, while the anonymous table boxes do have auto height, the <table>  
elements do not. The "div > *" rule sets it to 1em.

> Finally, 'display: block' set on the 2 table elements should make their
> used height furthermore convincing. box-sizing remains border-box
> (unchanged) even though those 2 table elements should be displayed as
> blocks.

Not sure what you mean here. Yes, it remains 'border-box', since the UA  
stylesheet just targets <table> and can't limit itself to cases where  
'display' is 'table'. So that means the height of the content box is  
expected to be 18px.

> This particular testcase creates/triggers more issues than testing well
> only one single CSS issue. As I said before, one idea would be to drop,
> to remove the borders around the 4 black stripes in order to simplify
> the testcase and make it more trustworthy. The testcase should be about
> CSS 2.1, not about how clientHeight or offsetHeight is calculated.

Yes, that seems like a good idea, since the test seems to be about margin  
collapsing and not table height calculations.

> [1]: http://www.w3.org/TR/CSS21/tables.html#model
> [2]: http://www.w3.org/TR/CSS21/tables.html#height-layout
> [3]: border widths are subtracted from table's intrinsic width
> https://bugzilla.mozilla.org/show_bug.cgi?id=96463


-- 
Øyvind Stenhaug
Core Norway, Opera Software ASA
Received on Friday, 12 November 2010 13:31:49 GMT

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