From 290cb1b5171306d0c9275cdb12be9cb6d85b08cd Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Tue, 23 Mar 2021 12:37:43 -0600
Subject: [PATCH] make retract_local_clauses safe, remove warning about
 overwriting warning in do_not_duplicate_path_components test

---
 src/machine/load_state.rs | 20 +++++++++++---------
 tests/scryer/issues.rs    |  1 -
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/machine/load_state.rs b/src/machine/load_state.rs
index d0754936..e59d4a2a 100644
--- a/src/machine/load_state.rs
+++ b/src/machine/load_state.rs
@@ -344,7 +344,7 @@ impl<'a> LoadState<'a> {
         key: PredicateKey,
         clause_locs: &SliceDeque<usize>,
     ) {
-        let (clause_target_poses, is_dynamic) = self
+        let result_opt = self
             .wam
             .indices
             .get_predicate_skeleton(&compilation_target, &key)
@@ -358,14 +358,16 @@ impl<'a> LoadState<'a> {
                     })
                     .collect(),
                  skeleton.is_dynamic)
-            }).unwrap();
-
-        self.retract_local_clauses_by_locs(
-            compilation_target,
-            key,
-            clause_target_poses,
-            is_dynamic,
-        );
+            });
+
+        if let Some((clause_target_poses, is_dynamic)) = result_opt {
+            self.retract_local_clauses_by_locs(
+                compilation_target,
+                key,
+                clause_target_poses,
+                is_dynamic,
+            );
+        }
     }
 
     pub(super) fn retract_local_clauses_by_locs(
diff --git a/tests/scryer/issues.rs b/tests/scryer/issues.rs
index 72f67194..7823cf43 100644
--- a/tests/scryer/issues.rs
+++ b/tests/scryer/issues.rs
@@ -29,7 +29,6 @@ fn do_not_duplicate_path_components() {
         "\
         caught: e\n\
         false.\n\
-        Warning: overwriting $initialization_goals/1\n\
         caught: e\n\
         false.\n\
         ",
-- 
2.54.0