1 files changed, 19 insertions, 0 deletions
diff --git a/tests/ui/mir/field-projection-mutating-context.rs b/tests/ui/mir/field-projection-mutating-context.rs
new file mode 100644
index 000000000..a1002c088
--- /dev/null
+++ b/tests/ui/mir/field-projection-mutating-context.rs
@@ -0,0 +1,19 @@
+use std::sync::Mutex;
+
+static GLOBAL: Mutex<&'static str> = Mutex::new("global str");
+
+struct Foo<T>(T); // `T` is covariant.
+
+fn foo() {
+    let mut x: Foo<for<'a> fn(&'a str)> = Foo(|_| ());
+    let Foo(ref mut y): Foo<fn(&'static str)> = x;
+    //~^ ERROR mismatched types
+    *y = |s| *GLOBAL.lock().unwrap() = s;
+    let string = String::from("i am shortlived");
+    (x.0)(&string);
+}
+
+fn main() {
+    foo();
+    println!("{}", GLOBAL.lock().unwrap());
+}