1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/associated-types/associated-types-duplicate-binding-in-env.rs b/src/test/ui/associated-types/associated-types-duplicate-binding-in-env.rs
new file mode 100644
index 000000000..9ffccd3d8
--- /dev/null
+++ b/src/test/ui/associated-types/associated-types-duplicate-binding-in-env.rs
@@ -0,0 +1,21 @@
+// run-pass
+#![allow(dead_code)]
+// Check that we do not report ambiguities when the same predicate
+// appears in the environment twice. Issue #21965.
+
+// pretty-expanded FIXME #23616
+
+trait Foo {
+    type B;
+
+    fn get() -> Self::B;
+}
+
+fn foo<T>() -> ()
+    where T : Foo<B=()>, T : Foo<B=()>
+{
+    <T as Foo>::get()
+}
+
+fn main() {
+}