[css-tables] Fixed visibility:collapse + position:absolute

Author: FremyCompany

css-tables-3/Overview.bs

@@ -2326,12 +2326,19 @@ With a table-root as containing block</h3>
 	</div>
 
 <h3 id="abspos-boxes-in-table-internal">
-With a table-track or table-track-group as containing block</h3>
+With a table-internal as containing block</h3>
 
 	If an absolutely positioned element's <a>containing block</a>
 	is generated by a <a>table-internal</a>,
-	the containing block corresponds to <a href="#bounding-box-assignment">the area defined for the box during layout</a>,
-	(these elements cannot have a border or padding, so they always refer to that area in its entirety).
+	the containing block corresponds to the area starting at the top left corner of the <a href="#bounding-box-assignment">the area that would be assigned to the box during layout</a>
+	but whose size is computed to be  the one of <a href="#bounding-box-assignment">the area that would be assigned to the box during layout</a> 
+		if all tracks were considered visible (irrespective of 'visibility' being set co collapse on some boxes),
+	not including borders and paddings as appropriate.
+
+	<div class="note">
+	This is done so that hiding column does not trigger a layout in the absolutely-positioned boxes, and the content being clipped doesn't seem to be moving.
+	<a class="hint" href="https://wptest.center/#/uxin57">!!Testcase</a> 
+	</div>
 
 	The offset properties ('top'/'right'/'bottom'/'left')
 	then indicate offsets inwards from the corresponding edges