Fix a race in the test_unistd::test_fchown test

The test was assuming that once dropped, a temporary file's file
descriptor would be invalid.  But it might not be, because another file
might be opened with the same file descriptor.  Instead, use an
obviously invalid file descriptor.

1 files changed, 1 insertions, 4 deletions

diff --git a/test/test_unistd.rs b/test/test_unistd.rs
index 113bef62..632e1be4 100644
--- a/test/test_unistd.rs
+++ b/test/test_unistd.rs
@@ -19,7 +19,6 @@ use std::ffi::CString;
 use std::fs::DirBuilder;
 use std::fs::{self, File};
 use std::io::Write;
-use std::mem;
 use std::os::unix::prelude::*;
 #[cfg(not(target_os = "redox"))]
 use std::path::Path;
@@ -466,9 +465,7 @@ fn test_fchown() {
     fchown(fd, uid, gid).unwrap();
     fchown(fd, uid, None).unwrap();
     fchown(fd, None, gid).unwrap();
-
-    mem::drop(path);
-    fchown(fd, uid, gid).unwrap_err();
+    fchown(999999999, uid, gid).unwrap_err();
 }
 
 #[test]