auto merge of #7987 : alexcrichton/rust/tests-for-closed-issues, r=huonw

Closes #5844

Author: bors

src/test/auxiliary/issue_5844_aux.rs

@@ -0,0 +1,16 @@
+// Copyright 2013 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.
+
+use std::libc;
+
+extern "C" {
+    pub fn rand() -> libc::c_int;
+}
+

src/test/compile-fail/issue-5844.rs

@@ -0,0 +1,18 @@
+// Copyright 2013 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.
+
+//aux-build:issue_5844_aux.rs
+
+extern mod issue_5844_aux;
+
+fn main () {
+    issue_5844_aux::rand(); //~ ERROR: requires unsafe
+}
+