1 files changed, 22 insertions, 0 deletions
diff --git a/tests/ui/traits/next-solver/normalize-unsize-rhs.rs b/tests/ui/traits/next-solver/normalize-unsize-rhs.rs
new file mode 100644
index 000000000..08bb0cf42
--- /dev/null
+++ b/tests/ui/traits/next-solver/normalize-unsize-rhs.rs
@@ -0,0 +1,22 @@
+// compile-flags: -Znext-solver
+// check-pass
+#![feature(trait_upcasting)]
+
+trait A {}
+trait B: A {}
+
+impl A for usize {}
+impl B for usize {}
+
+trait Mirror {
+    type Assoc: ?Sized;
+}
+
+impl<T: ?Sized> Mirror for T {
+    type Assoc = T;
+}
+
+fn main() {
+    let x = Box::new(1usize) as Box<<dyn B as Mirror>::Assoc>;
+    let y = x as Box<<dyn A as Mirror>::Assoc>;
+}