1 files changed, 32 insertions, 0 deletions
diff --git a/src/test/ui/traits/issue-23003.rs b/src/test/ui/traits/issue-23003.rs
new file mode 100644
index 000000000..24c2b2ad6
--- /dev/null
+++ b/src/test/ui/traits/issue-23003.rs
@@ -0,0 +1,32 @@
+// run-pass
+// Test stack overflow triggered by evaluating the implications. To be
+// WF, the type `Receipt<Complete>` would require that `<Complete as
+// Async>::Cancel` be WF. This normalizes to `Receipt<Complete>`
+// again, leading to an infinite cycle. Issue #23003.
+
+// pretty-expanded FIXME #23616
+
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+use std::marker::PhantomData;
+
+trait Async {
+    type Cancel;
+}
+
+struct Receipt<A:Async> {
+    marker: PhantomData<A>,
+}
+
+struct Complete {
+    core: Option<()>,
+}
+
+impl Async for Complete {
+    type Cancel = Receipt<Complete>;
+}
+
+fn foo(r: Receipt<Complete>) { }
+
+fn main() { }