Merge ref '6bcdcc73bd11' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: 6bcdcc73bd11568fd85f5a38b58e1eda054ad1cd
Filtered ref: 6cc4ce79e1f8dc0ec5a2e18049b9c1a51dee3221

This merge was created using https://github.com/rust-lang/josh-sync.

1 files changed, 9 insertions, 1 deletions

diff --git a/tests/ui/generics/generic-extern.rs b/tests/ui/generics/generic-extern.rs
index 36fa5eaafd6..b4f00fc1187 100644
--- a/tests/ui/generics/generic-extern.rs
+++ b/tests/ui/generics/generic-extern.rs
@@ -1,7 +1,15 @@
+// Ensure that we reject generic parameters on foreign items.
+
 extern "C" {
     fn foo<T>(); //~ ERROR foreign items may not have type parameters
+
+    // Furthermore, check that type parameter defaults lead to a *hard* error,
+    // not just a lint error, for maximum forward compatibility.
+    #[allow(invalid_type_param_default)] // Should have no effect here.
+    fn bar<T = ()>(); //~ ERROR foreign items may not have type parameters
+    //~^ ERROR defaults for generic parameters are not allowed here
 }
 
 fn main() {
-    foo::<i32>(); //~ ERROR requires unsafe
+    unsafe { foo::<i32>() };
 }