1 files changed, 23 insertions, 0 deletions
diff --git a/tests/ui/borrowck/borrowck-assign-to-subfield.rs b/tests/ui/borrowck/borrowck-assign-to-subfield.rs
new file mode 100644
index 000000000..050d702b6
--- /dev/null
+++ b/tests/ui/borrowck/borrowck-assign-to-subfield.rs
@@ -0,0 +1,23 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+pub fn main() {
+    struct A {
+        a: isize,
+        w: B,
+    }
+    struct B {
+        a: isize
+    }
+    let mut p = A {
+        a: 1,
+        w: B {a: 1},
+    };
+
+    // even though `x` is not declared as a mutable field,
+    // `p` as a whole is mutable, so it can be modified.
+    p.a = 2;
+
+    // this is true for an interior field too
+    p.w.a = 2;
+}