1 files changed, 15 insertions, 0 deletions
diff --git a/src/test/ui/nll/relate_tys/hr-fn-aba-as-aaa.rs b/src/test/ui/nll/relate_tys/hr-fn-aba-as-aaa.rs
new file mode 100644
index 000000000..7cc0acf45
--- /dev/null
+++ b/src/test/ui/nll/relate_tys/hr-fn-aba-as-aaa.rs
@@ -0,0 +1,15 @@
+// Test that the NLL `relate_tys` code correctly deduces that a
+// function returning always its first argument can be upcast to one
+// that returns either first or second argument.
+//
+// check-pass
+// compile-flags:-Zno-leak-check
+
+fn make_it() -> for<'a, 'b> fn(&'a u32, &'b u32) -> &'a u32 {
+    panic!()
+}
+
+fn main() {
+    let a: for<'a> fn(&'a u32, &'a u32) -> &'a u32 = make_it();
+    drop(a);
+}