From 823e2e784220d96b5ca27f0a6b2751994958c965 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Thu, 14 Dec 2023 07:57:36 +0100
Subject: [PATCH] add test for uninhabited saved locals in a coroutine

---
 src/tools/miri/tests/pass/coroutine.rs | 31 ++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/tools/miri/tests/pass/coroutine.rs b/src/tools/miri/tests/pass/coroutine.rs
index 49bfa92a052..7e1f64df04d 100644
--- a/src/tools/miri/tests/pass/coroutine.rs
+++ b/src/tools/miri/tests/pass/coroutine.rs
@@ -220,7 +220,38 @@ fn smoke_resume_arg() {
     });
 }
 
+fn uninit_fields() {
+    // Test that uninhabited saved local doesn't make the entire variant uninhabited.
+    // (https://github.com/rust-lang/rust/issues/115145, https://github.com/rust-lang/rust/pull/118871)
+    fn conjure<T>() -> T {
+        loop {}
+    }
+
+    fn run<T>(x: bool, y: bool) {
+        let mut c = || {
+            if x {
+                let _a: T;
+                if y {
+                    _a = conjure::<T>();
+                }
+                yield ();
+            } else {
+                let _a: T;
+                if y {
+                    _a = conjure::<T>();
+                }
+                yield ();
+            }
+        };
+        assert!(matches!(Pin::new(&mut c).resume(()), CoroutineState::Yielded(())));
+        assert!(matches!(Pin::new(&mut c).resume(()), CoroutineState::Complete(())));
+    }
+
+    run::<!>(false, false);
+}
+
 fn main() {
     basic();
     smoke_resume_arg();
+    uninit_fields();
 }