testsuite: Add xfailed test for #8498

Author: catamorphism

src/test/run-pass/issue-8498.rs

@@ -0,0 +1,44 @@
+// 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.
+
+// xfail-test
+use std::io;
+
+fn main() {
+// This is ok
+    match &[(~5,~7)] {
+        ps => {
+           let (ref y, _) = ps[0];
+           io::println(fmt!("1. y = %d", **y));
+           assert!(**y == 5);
+        }
+    }
+
+// This is not entirely ok
+    match Some(&[(~5,)]) {
+        Some(ps) => {
+           let (ref y,) = ps[0];
+           io::println(fmt!("2. y = %d", **y));
+           if **y != 5 { io::println("sadness"); }
+        }
+        None => ()
+    }
+
+// This is not ok
+    match Some(&[(~5,~7)]) {
+        Some(ps) => {
+           let (ref y, ref z) = ps[0];
+           io::println(fmt!("3. y = %d z = %d", **y, **z));
+           assert!(**y == 5);
+        }
+        None => ()
+    }
+}
+