Regression test for Issue 21400.

Fix #21400.

src/test/run-pass/issue-21400.rs

@@ -0,0 +1,66 @@
+// 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.
+
+// Regression test for #21400 which itself was extracted from
+// stackoverflow.com/questions/28031155/is-my-borrow-checker-drunk/28031580
+
+fn main() {
+    let mut t = Test;
+    assert_eq!(t.method1("one"), Ok(1));
+    assert_eq!(t.method2("two"), Ok(2));
+    assert_eq!(t.test(), Ok(2));
+}
+
+struct Test;
+
+impl Test {
+    fn method1(&mut self, _arg: &str) -> Result<usize, &str> {
+        Ok(1)
+    }
+
+    fn method2(self: &mut Test, _arg: &str) -> Result<usize, &str> {
+        Ok(2)
+    }
+
+    fn test(self: &mut Test) -> Result<usize, &str> {
+        let s = format!("abcde");
+        // (Originally, this invocation of method2 was saying that `s`
+        // does not live long enough.)
+        let data = match self.method2(&*s) {
+            Ok(r) => r,
+            Err(e) => return Err(e)
+        };
+        Ok(data)
+    }
+}
+
+// Below is a closer match for the original test that was failing to compile
+
+pub struct GitConnect;
+
+impl GitConnect {
+    fn command(self: &mut GitConnect, _s: &str) -> Result<Vec<Vec<u8>>, &str> {
+        unimplemented!()
+    }
+
+    pub fn git_upload_pack(self: &mut GitConnect) -> Result<String, &str> {
+        let c = format!("git-upload-pack");
+
+        let mut out = String::new();
+        let data = try!(self.command(&c));
+
+        for line in data.iter() {
+            out.push_str(&format!("{:?}", line));
+        }
+
+        Ok(out)
+    }
+}
+