If the "order by" clause is used in a FLWOR expression,
and the "return" clause returns a sequence of more than
one item, items after the first are discarded. For example:
for $w in (3,2,1)
order by $w
return ($w, $w+10)
returns (1,2,3) instead of (1, 11, 2, 12, 3, 13).
Source code fixed and test case added (qxmp122).