Fix private module loophole in the 'private type in public item' check

1 files changed, 28 insertions, 0 deletions

diff --git a/src/test/compile-fail/priv_in_pub_sig_priv_mod.rs b/src/test/compile-fail/priv_in_pub_sig_priv_mod.rs
new file mode 100644
index 00000000000..f589daf3f39
--- /dev/null
+++ b/src/test/compile-fail/priv_in_pub_sig_priv_mod.rs
@@ -0,0 +1,28 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that we properly check for private types in public signatures, even
+// inside a private module (#22261).
+
+mod a {
+    struct Priv;
+
+    pub fn expose_a() -> Priv { //~Error: private type in exported type signature
+        panic!();
+    }
+
+    mod b {
+        pub fn expose_b() -> super::Priv { //~Error: private type in exported type signature
+            panic!();
+        }
+    }
+}
+
+pub fn main() {}