1 files changed, 51 insertions, 0 deletions
diff --git a/tests/ui/unsafe/union_destructure.rs b/tests/ui/unsafe/union_destructure.rs
new file mode 100644
index 00000000000..6c88344b5fd
--- /dev/null
+++ b/tests/ui/unsafe/union_destructure.rs
@@ -0,0 +1,51 @@
+// run-pass
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
+#[derive(Copy, Clone)]
+#[allow(dead_code)]
+struct Pie {
+    slices: u8,
+    size: u8,
+}
+
+union Foo {
+    #[allow(dead_code)]
+    bar: i8,
+    baz: Pie
+}
+
+fn main() {
+    let u = Foo { bar: 5 };
+    let (Some(Foo { bar: _ }) | None) = Some(u);
+    let u = Foo { bar: 6 };
+    let (Some(Foo { bar: _ }) | Some(Foo { bar: _ }) | None) = Some(u);
+    unsafe {
+        let u = Foo { bar: 7 };
+        let (Foo { bar } | Foo { bar }) = u;
+        assert_eq!(bar, 7)
+    }
+    let u = Foo { bar: 8 };
+    match Some(u) {
+        Some(Foo { bar: _ }) => 3,
+        None => 4,
+    };
+
+    let u = Foo { bar: 9 };
+    unsafe { //[mir]~ WARNING unnecessary `unsafe` block
+        match u {
+            Foo { baz: Pie { .. } } => {},
+        };
+    }
+    let u = Foo { bar: 10 };
+    unsafe { //[mir]~ WARNING unnecessary `unsafe` block
+        match u {
+            Foo { baz: Pie { slices: _, size: _ } } => {},
+        };
+    }
+
+    let u = Foo { bar: 11 };
+    match u {
+        Foo { baz: _ } => {},
+    };
+}