1 files changed, 37 insertions, 0 deletions
diff --git a/third_party/rust/maybe-uninit/tests/doesnt_drop.rs b/third_party/rust/maybe-uninit/tests/doesnt_drop.rs
new file mode 100644
index 0000000000..1d4b30fc46
--- /dev/null
+++ b/third_party/rust/maybe-uninit/tests/doesnt_drop.rs
@@ -0,0 +1,37 @@
+extern crate maybe_uninit;
+use maybe_uninit::MaybeUninit;
+
+use std::cell::Cell;
+
+struct DecrementOnDrop<'a>(&'a Cell<usize>);
+
+impl<'a> DecrementOnDrop<'a> {
+    pub fn new(ref_:&'a Cell<usize>) -> Self {
+        ref_.set(1);
+        DecrementOnDrop(ref_)
+    }
+}
+
+impl<'a> Clone for DecrementOnDrop<'a> {
+    fn clone(&self) -> Self {
+        self.0.set(self.0.get() + 1);
+
+        DecrementOnDrop(self.0)
+    }
+}
+
+impl<'a> Drop for DecrementOnDrop<'a>{
+    fn drop(&mut self) {
+        self.0.set(self.0.get() - 1);
+    }
+}
+
+#[test]
+fn doesnt_drop(){
+    let count = Cell::new(0);
+    let arc = DecrementOnDrop::new(&count);
+    let maybe = MaybeUninit::new(arc.clone());
+    assert_eq!(count.get(), 2);
+    drop(maybe);
+    assert_eq!(count.get(), 2);
+}