1 files changed, 30 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-18906.rs b/src/test/ui/issues/issue-18906.rs
new file mode 100644
index 000000000..976a9f49b
--- /dev/null
+++ b/src/test/ui/issues/issue-18906.rs
@@ -0,0 +1,30 @@
+// check-pass
+#![allow(dead_code)]
+// pretty-expanded FIXME #23616
+
+pub trait Borrow<Borrowed: ?Sized> {
+        fn borrow(&self) -> &Borrowed;
+}
+
+impl<T: Sized> Borrow<T> for T {
+        fn borrow(&self) -> &T { self }
+}
+
+trait Foo {
+        fn foo(&self, other: &Self);
+}
+
+fn bar<K, Q>(k: &K, q: &Q) where K: Borrow<Q>, Q: Foo {
+    q.foo(k.borrow())
+}
+
+struct MyTree<K>(K);
+
+impl<K> MyTree<K> {
+    // This caused a failure in #18906
+    fn bar<Q>(k: &K, q: &Q) where K: Borrow<Q>, Q: Foo {
+        q.foo(k.borrow())
+    }
+}
+
+fn main() {}