1 files changed, 46 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-38437.rs b/src/test/ui/issues/issue-38437.rs
new file mode 100644
index 000000000..e14121690
--- /dev/null
+++ b/src/test/ui/issues/issue-38437.rs
@@ -0,0 +1,46 @@
+// run-pass
+#![allow(dead_code)]
+// Check that drop elaboration clears the "master" discriminant
+// drop flag even if it protects no fields.
+
+struct Good(usize);
+impl Drop for Good {
+    #[inline(never)]
+    fn drop(&mut self) {
+        println!("dropping Good({})", self.0);
+    }
+}
+
+struct Void;
+impl Drop for Void {
+    #[inline(never)]
+    fn drop(&mut self) {
+        panic!("Suddenly, a Void appears.");
+    }
+}
+
+enum E {
+    Never(Void),
+    Fine(Good)
+}
+
+fn main() {
+    let mut go = true;
+
+    loop {
+        let next;
+        match go {
+            true => next = E::Fine(Good(123)),
+            false => return,
+        }
+
+        match next {
+            E::Never(_) => return,
+            E::Fine(_good) => go = false,
+        }
+
+        // `next` is dropped and StorageDead'd here. We must reset the
+        // discriminant's drop flag to avoid random variants being
+        // dropped.
+    }
+}