[csswg-drafts] [css-overflow] body overflow propagation is less defined than it was in CSS 2.1

bzbarsky has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-overflow] body overflow propagation is less defined than it was in CSS 2.1 ==
CSS2.1 says (at <https://www.w3.org/TR/CSS21/visufx.html#overflow-clipping>):

> 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'.

while https://drafts.csswg.org/css-overflow-3/#overflow-propagation says:

> UAs must apply the overflow property set on the root element to the viewport. For HTML UAs, if this would result in the viewport having visible overflow, the UA must instead apply the overflow property set on the body element to the viewport.

The CSS2.1 version defines what to do when there are multiple `<body>` elements, but the draft css-overflow version does not.  This should be fixed, and web platform tests added.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/1905 using your GitHub account

Received on Wednesday, 25 October 2017 14:53:56 UTC