1 files changed, 19 insertions, 0 deletions
diff --git a/tests/ui/lint/undropped_manually_drops.rs b/tests/ui/lint/undropped_manually_drops.rs
new file mode 100644
index 000000000..7286121a4
--- /dev/null
+++ b/tests/ui/lint/undropped_manually_drops.rs
@@ -0,0 +1,19 @@
+// check-fail
+
+struct S;
+
+fn main() {
+    let mut manual1 = std::mem::ManuallyDrop::new(S);
+    let mut manual2 = std::mem::ManuallyDrop::new(S);
+    let mut manual3 = std::mem::ManuallyDrop::new(S);
+
+    drop(std::mem::ManuallyDrop::new(S)); //~ ERROR calls to `std::mem::drop`
+    drop(manual1); //~ ERROR calls to `std::mem::drop`
+    drop({ manual3 }); //~ ERROR calls to `std::mem::drop`
+
+    // These lines will drop `S` and should be okay.
+    unsafe {
+        std::mem::ManuallyDrop::drop(&mut std::mem::ManuallyDrop::new(S));
+        std::mem::ManuallyDrop::drop(&mut manual2);
+    }
+}