1 files changed, 45 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-16774.rs b/tests/ui/issues/issue-16774.rs
new file mode 100644
index 00000000000..2b308ef76e4
--- /dev/null
+++ b/tests/ui/issues/issue-16774.rs
@@ -0,0 +1,45 @@
+// run-pass
+#![feature(box_patterns)]
+
+use std::ops::{Deref, DerefMut};
+
+struct X(Box<isize>);
+
+static mut DESTRUCTOR_RAN: bool = false;
+
+impl Drop for X {
+    fn drop(&mut self) {
+        unsafe {
+            assert!(!DESTRUCTOR_RAN);
+            DESTRUCTOR_RAN = true;
+        }
+    }
+}
+
+impl Deref for X {
+    type Target = isize;
+
+    fn deref(&self) -> &isize {
+        let &X(box ref x) = self;
+        x
+    }
+}
+
+impl DerefMut for X {
+    fn deref_mut(&mut self) -> &mut isize {
+        let &mut X(box ref mut x) = self;
+        x
+    }
+}
+
+fn main() {
+    {
+        let mut test = X(Box::new(5));
+        {
+            let mut change = || { *test = 10 };
+            change();
+        }
+        assert_eq!(*test, 10);
+    }
+    assert!(unsafe { DESTRUCTOR_RAN });
+}