XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyBBBBeeeessssttttCCCChhhhaaaannnnnnnneeeellllRRRReeeeccccttttaaaannnngggglllleeee returns TRUE if a rectangle
is found of a valid supported size and origin (the valid
size of which is found in the returned variables); this
function returns FALSE when no valid rectangle was found
(among which is the case when the server does not support
change of size or origin).
Parameter errors are reported via BadValue or BadMatch.