2992 - percentage values on top and bottom

Status: VERIFIED INVALID

(Core :: Layout, defect, P2)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Percentage values on the top (and bottom?) properties don't work with relative
positioning (and absolute positioning??) when the height of the containing
block is auto.  See the <P class="two"> in the above URL.  The relative
positioning works if I stick style="height: 200px" in its containing DIV.

Comment 1

[troy]

I'm doing what the CSS2 spec says in this respect. Their behavior is different
for 'top' and 'bottom' than for 'margin-top' and 'margin-bottom' (for example),
where the height is always based on the containing block width

According to 9.3.2:

<percentage>
     The offset is a percentage of the containing block's width (for 'left' or
'right') or height (for 'top' and 'bottom'). For 'top' and 'bottom', if the
height of the containing block is not specified explicitly (i.e., it depends on
content height), the percentage value is interpreted like 'auto'.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Yup.  I missed that.  Verified invalid.

Comment 3

[webboy]

In the mean time CSS 2.1 has come out. It says in 9.3.2:


<percentage> 
The offset is a percentage of the containing block's width (for 'left' or
'right') or height (for 'top' and 'bottom'). Negative values are allowed.

So the bug is valid now.

Comment 4

[Roman]

Bug 260348 is the currently-open variant of this bug.