1 files changed, 12 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-20953.rs b/tests/ui/issues/issue-20953.rs
new file mode 100644
index 000000000..4ec7e3195
--- /dev/null
+++ b/tests/ui/issues/issue-20953.rs
@@ -0,0 +1,12 @@
+// run-pass
+#![allow(unused_mut)]
+#![allow(unused_variables)]
+fn main() {
+    let mut shrinker: Box<dyn Iterator<Item=i32>> = Box::new(vec![1].into_iter());
+    println!("{:?}", shrinker.next());
+    for v in shrinker { assert!(false); }
+
+    let mut shrinker: &mut dyn Iterator<Item=i32> = &mut vec![1].into_iter();
+    println!("{:?}", shrinker.next());
+    for v in shrinker { assert!(false); }
+}