+// 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.
+
+fn main() {
+ // -------- Simplified test case --------
+
+ let _ = || 0..=1;
+
+ // -------- Original test case --------
+
+ let full_length = 1024;
+ let range = {
+ // do some stuff, omit here
+ None
+ };
+
+ let range = range.map(|(s, t)| s..=t).unwrap_or(0..=(full_length-1));
+
+ assert_eq!(range, 0..=1023);
+}