1 files changed, 41 insertions, 0 deletions
diff --git a/tests/ui/methods/method-recursive-blanket-impl.rs b/tests/ui/methods/method-recursive-blanket-impl.rs
new file mode 100644
index 000000000..a2db75b4e
--- /dev/null
+++ b/tests/ui/methods/method-recursive-blanket-impl.rs
@@ -0,0 +1,41 @@
+// run-pass
+#![allow(unused_variables)]
+#![allow(unused_imports)]
+// Test that we don't trigger on the blanket impl for all `&'a T` but
+// rather keep autoderefing and trigger on the underlying impl.  To
+// know not to stop at the blanket, we have to recursively evaluate
+// the `T:Foo` bound.
+
+// pretty-expanded FIXME #23616
+
+use std::marker::Sized;
+
+// Note: this must be generic for the problem to show up
+trait Foo<A> {
+    fn foo(&self, a: A);
+}
+
+impl Foo<u8> for [u8] {
+    fn foo(&self, a: u8) {}
+}
+
+impl<'a, A, T> Foo<A> for &'a T where T: Foo<A> {
+    fn foo(&self, a: A) {
+        Foo::foo(*self, a)
+    }
+}
+
+trait Bar {
+    fn foo(&self);
+}
+
+struct MyType;
+
+impl Bar for MyType {
+    fn foo(&self) {}
+}
+
+fn main() {
+    let mut m = MyType;
+    (&mut m).foo()
+}