1 files changed, 37 insertions, 0 deletions
diff --git a/tests/ui/unsafe/union-modification.rs b/tests/ui/unsafe/union-modification.rs
new file mode 100644
index 00000000000..9a53ef90852
--- /dev/null
+++ b/tests/ui/unsafe/union-modification.rs
@@ -0,0 +1,37 @@
+// run-pass
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
+union Foo {
+    bar: i8,
+    _blah: isize,
+    _zst: (),
+}
+
+struct FooHolder {
+    inner_foo: Foo
+}
+
+fn do_nothing(_x: &mut Foo) {}
+
+pub fn main() {
+    let mut foo = Foo { bar: 5 };
+    do_nothing(&mut foo);
+    foo.bar = 6;
+    unsafe { foo.bar += 1; }
+    assert_eq!(unsafe { foo.bar }, 7);
+    unsafe {
+        let Foo { bar: inner } = foo;
+        assert_eq!(inner, 7);
+    }
+
+    let foo = Foo { bar: 5 };
+    let foo = if let 3 = if let true = true { 3 } else { 4 } { foo } else { foo };
+
+    let (_foo2, _random) = (foo, 42);
+
+    let mut foo_holder = FooHolder { inner_foo: Foo { bar: 5 } };
+    foo_holder.inner_foo.bar = 4;
+    assert_eq!(unsafe { foo_holder.inner_foo.bar }, 4);
+    drop(foo_holder);
+}