Range of integer values (wrt 1 Microsoft z-index test)

Hello all,

This test

http://test.csswg.org/source/contributors/microsoft/submitted/Chapter_9/z-index-001.xht

must be reviewed, reassessed.

Its assertion field states something that CSS 2.1 spec does not specify,
does not define anywhere:

<meta name="assert" content="The property z-index set to a minimum value
minus 1 is correctly truncated to the minimum value.">


http://www.w3.org/TR/CSS21/visuren.html#propdef-z-index
makes no mentions of any truncation method and of any specific (floor)
minimum value


Section 4.3.1 Integers and real numbers
http://www.w3.org/TR/CSS21/syndata.html#numbers

states

"
Note that many properties that allow an integer or real number as a
value actually restrict the value to some range, often to a non-negative
value.
"

but does not state and does not suggest any floor and/or ceiling values.

regards, Gérard