1 files changed, 19 insertions, 0 deletions
diff --git a/src/test/mir-opt/remove_zsts_dont_touch_unions.rs b/src/test/mir-opt/remove_zsts_dont_touch_unions.rs
new file mode 100644
index 000000000..7a6f86b80
--- /dev/null
+++ b/src/test/mir-opt/remove_zsts_dont_touch_unions.rs
@@ -0,0 +1,19 @@
+// compile-flags: -Zmir-opt-level=3
+
+// Ensure RemoveZsts doesn't remove ZST assignments to union fields,
+// which causes problems in Miri.
+
+union Foo {
+    x: (),
+    y: u64,
+}
+
+// EMIT_MIR remove_zsts_dont_touch_unions.get_union.RemoveZsts.after.mir
+fn get_union() -> Foo {
+    Foo { x: () }
+}
+
+
+fn main() {
+    get_union();
+}