resolve panic caused by lingering attribute goals (#253)

2019-12-06 15:22:28 -04:00
parent 90e1c990e5
commit 5ccd334555
3 changed files with 10 additions and 2 deletions
--- a/src/prolog/machine/system_calls.rs
+++ b/src/prolog/machine/system_calls.rs
@@ -1376,6 +1376,9 @@ impl MachineState {
            &SystemClauseType::TruncateIfNoLiftedHeapGrowth => {
                self.truncate_if_no_lifted_heap_diff(|_| Addr::Con(Constant::EmptyList))
            }
+            &SystemClauseType::ClearAttributeGoals => {
+                self.attr_var_init.attribute_goals.clear();
+            }
            &SystemClauseType::CloneAttributeGoals => {
                let attr_goals = self.attr_var_init.attribute_goals.clone();
                self.fetch_attribute_goals(attr_goals);