Add a test for the default allocation error hook

Author: SimonSapin

src/test/run-pass/default-alloc-error-hook.rs

@@ -0,0 +1,28 @@
+// Copyright 2018 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.
+
+// ignore-cloudabi no processes
+// ignore-emscripten no processes
+
+use std::alloc::{Layout, handle_alloc_error};
+use std::env;
+use std::process::Command;
+use std::str;
+
+fn main() {
+    if env::args().len() > 1 {
+        handle_alloc_error(Layout::new::<[u8; 42]>())
+    }
+
+    let me = env::current_exe().unwrap();
+    let output = Command::new(&me).arg("next").output().unwrap();
+    assert!(!output.status.success(), "{:?} is a success", output.status);
+    assert_eq!(str::from_utf8(&output.stderr).unwrap(), "memory allocation of 42 bytes failed");
+}