Fix feedback in 'sweeprolog-set-prolog-flag'

Similarly to the previous fix for 'sweeprolog-pack-install', this
makes 'sweeprolog-set-prolog-flag' actually report its result, instead
of reporting failure even when successful.

* sweep.pl (sweep_set_prolog_flag/2): Bind the output argument to
non-nil on success.

diff --git a/sweep.pl b/sweep.pl
index 01ad05e86550c1f11280ad29a8231b274250e79a..38bdd1bb65e977b34f2e3cf369f50432d3f829a8 100644 (file)
--- a/sweep.pl
+++ b/sweep.pl
@@ -179,7 +179,7 @@ sweep_current_prolog_flags(Sub, Flags) :-
              term_string(Value0, Value)),
             Flags).
 
-sweep_set_prolog_flag([Flag0|Value0], []) :-
+sweep_set_prolog_flag([Flag0|Value0], true) :-
     atom_string(Flag, Flag0),
     term_string(Value, Value0),
     set_prolog_flag(Flag, Value).