1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-90638.rs b/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-90638.rs
new file mode 100644
index 000000000..18b7f3834
--- /dev/null
+++ b/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-90638.rs
@@ -0,0 +1,37 @@
+//check-pass
+
+#![feature(generic_associated_types)]
+
+trait Yokeable<'a>: 'static {
+    type Output: 'a;
+}
+
+trait IsCovariant<'a> {}
+
+struct Yoke<Y: for<'a> Yokeable<'a>> {
+    data: Y,
+}
+
+impl<Y: for<'a> Yokeable<'a>> Yoke<Y> {
+    fn project<Y2: for<'a> Yokeable<'a>>(&self, _f: for<'a> fn(<Y as Yokeable<'a>>::Output, &'a ())
+      -> <Y2 as Yokeable<'a>>::Output) -> Yoke<Y2> {
+
+        unimplemented!()
+    }
+}
+
+fn _upcast<Y>(x: Yoke<Y>) -> Yoke<Box<dyn IsCovariant<'static> + 'static>> where
+    Y: for<'a> Yokeable<'a>,
+    for<'a> <Y as Yokeable<'a>>::Output: IsCovariant<'a>
+    {
+    x.project(|data, _| {
+        Box::new(data)
+    })
+}
+
+
+impl<'a> Yokeable<'a> for Box<dyn IsCovariant<'static> + 'static> {
+    type Output = Box<dyn IsCovariant<'a> + 'a>;
+}
+
+fn main() {}