W3C home > Mailing lists > Public > www-style@w3.org > July 2008

Re: [CSS21] CR-CSS21-20070719, 8.3.1 Collapsing in presence of min/max-height, small correction suggested

From: Arron Eicholz <Arron.Eicholz@microsoft.com>
Date: Mon, 21 Jul 2008 13:53:32 -0700
To: "www-style@w3.org" <www-style@w3.org>
Message-ID: <66D5CB5D6AB0694592FAF5487C50368B21236A01B6@NA-EXMSG-C111.redmond.corp.microsoft.com>

> In 8.3.1:
> "The bottom margin of an in-flow block-level element with a 'height' of
> 'auto' and 'min-height' less than the element's used height and 'max-height'
> greater than the element's used height is adjoining to its last in-flow
> block-level child's bottom margin..."
> I suggest the following small corrections:
> - "less than" should be "less than or equal" (or "not greater than")
> - "greater than" should be "greater than or equal" (or "not less than")
> This would be more consistent with the rules at 10.7 and more logical:
> roughly speaking when min-height is exactly equal to the element's used
> height, then min-height is not really in effect, and all should be as in the
> case of min-height less than the element's used height.
> Firefox is the only browser that I know that stops that margins collapsing
> when min/max-height is in effect, and it behaves according to the suggested
> change.

Fantasai and Arron wrote some tests for this issue:
from which we conclude that
  - Safari and Opera do not disable margin collapsing when min-height or
    max-height is in effect.
  - IE never collapses
  - Firefox collapses when min-height or max-height is equal to the height,
    *eats* the inner margins both when max-height is in effect /and/ when
    min-height is in effect. We would expect that disabling margin-collapsing
    when min-height is effect would cause the margins to add, not the inner
    margin to be truncated.
and therefore this entire paragraph should be removed from the spec.

Fantasai and Arron Eicholz
Received on Monday, 21 July 2008 20:54:13 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:55:10 GMT