follow marked variables to end in eager_stackful_iter (#2100, #2101)

src/tests/term_variables.pl

@@ -43,12 +43,34 @@ test("term_variables#2097", (
     T = [[[A|B]|A]|A], Vs == [A,B]
 )).
 
+test("term_variables#2100", (
+    termt2(T), term_variables(T,Vs),
+    T = [[T|A]|B], Vs == [A,B]
+)).
+
+test("term_variables#2101", (
+    termt3(T), term_variables(T,Vs),
+    T = [[[[A|B]|A]|A]|A], Vs == [A, B]
+)).
+
 termt(T) :-
    T = [T1|T2],
    T1 = [T3|A],
    T3 = [A|_],
    T2 = A.
 
+termt2(T) :-
+   T = [T1|_B],
+   T1 = [T|_A].
+
+termt3(T) :-
+   T = [T1|T0],
+   T1 = [T2|T3],
+   T2 = [T4|A],
+   T4 = [A|_],
+   T3 = A,
+   T0 = A.
+
 main :-
     findall(test(Name, Goal), test(Name, Goal), Tests),
     run_tests(Tests, Failed),