Fix at_end_of_stream/1 predicate missing check for instantiation error
@@ -1607,7 +1607,9 @@ stream_property(S, P) :-
at_end_of_stream(S_or_a) :-
- ( atom(S_or_a) ->
+ ( var(S_or_a) ->
+ throw(error(instantiation_error, at_end_of_stream/1))
+ ; atom(S_or_a) ->
stream_property(S, alias(S_or_a))
; S = S_or_a
),
