An element with position:absoulte; right:auto; left:auto; whose parent has direction:rtl ends up having incorrect horizontal position. See the URL (where the ticker text is on the wrong side of the page) or the attached testcase. (Firefox does not render the 2-box test case as expected due to what I think is a bug in Firefox; WinIE does not have that bug but renders it incorrectly because of borders).
Created attachment 4764 [details] testcase This can go into fast/block/positioning/auto
Created attachment 4765 [details] Calculate the distance from the right correctly in this case Also removed a couple of redundant checks.
Comment on attachment 4765 [details] Calculate the distance from the right correctly in this case r=me