1 files changed, 14 insertions, 0 deletions
diff --git a/library/std/tests/windows.rs b/library/std/tests/windows.rs
new file mode 100644
index 00000000000..9f7596f1bc2
--- /dev/null
+++ b/library/std/tests/windows.rs
@@ -0,0 +1,14 @@
+#![cfg(windows)]
+//! An external tests
+
+use std::{ffi::OsString, os::windows::ffi::OsStringExt, path::PathBuf};
+
+#[test]
+#[should_panic]
+fn os_string_must_know_it_isnt_utf8_issue_126291() {
+    let mut utf8 = PathBuf::from(OsString::from("utf8".to_owned()));
+    let non_utf8: OsString =
+        OsStringExt::from_wide(&[0x6e, 0x6f, 0x6e, 0xd800, 0x75, 0x74, 0x66, 0x38]);
+    utf8.set_extension(&non_utf8);
+    utf8.into_os_string().into_string().unwrap();
+}