1 files changed, 18 insertions, 0 deletions
diff --git a/library/alloc/tests/c_str.rs b/library/alloc/tests/c_str.rs
new file mode 100644
index 00000000000..8fbb10e1d5c
--- /dev/null
+++ b/library/alloc/tests/c_str.rs
@@ -0,0 +1,18 @@
+use std::borrow::Cow::{Borrowed, Owned};
+use std::ffi::{c_char, CStr};
+
+#[test]
+fn to_str() {
+    let data = b"123\xE2\x80\xA6\0";
+    let ptr = data.as_ptr() as *const c_char;
+    unsafe {
+        assert_eq!(CStr::from_ptr(ptr).to_str(), Ok("123…"));
+        assert_eq!(CStr::from_ptr(ptr).to_string_lossy(), Borrowed("123…"));
+    }
+    let data = b"123\xE2\0";
+    let ptr = data.as_ptr() as *const c_char;
+    unsafe {
+        assert!(CStr::from_ptr(ptr).to_str().is_err());
+        assert_eq!(CStr::from_ptr(ptr).to_string_lossy(), Owned::<str>(format!("123\u{FFFD}")));
+    }
+}