Fix port of test code to nix 0.29 to avoid flaky failures

clircle-handle_ownedfd_for_nix_ge_0_27.diff

@@ -1,3 +1,5 @@
+diff --git a/src/clircle_unix.rs b/src/clircle_unix.rs
+index 101f208..56448b9 100644
 --- a/src/clircle_unix.rs
 +++ b/src/clircle_unix.rs
 @@ -4,7 +4,7 @@ use std::convert::TryFrom;
@@ -5,11 +7,33 @@
  use std::io::{self, Seek};
  use std::os::unix::fs::MetadataExt;
 -use std::os::unix::io::{FromRawFd, IntoRawFd, RawFd};
-+use std::os::unix::io::{AsRawFd,FromRawFd, IntoRawFd, RawFd};
++use std::os::unix::io::{FromRawFd, IntoRawFd, OwnedFd, RawFd};
  use std::{cmp, hash, ops};
  
  /// Re-export of libc
-@@ -186,7 +186,7 @@ mod tests {
+@@ -53,6 +53,13 @@ impl UnixIdentifier {
+             ident
+         })
+     }
++
++    fn try_from_owned_fd(fd: OwnedFd) -> io::Result<Self> {
++        Self::try_from(File::from(fd)).map(|mut ident| {
++            ident.owns_fd = true;
++            ident
++        })
++    }
+ }
+ 
+ impl Clircle for UnixIdentifier {
+@@ -135,6 +142,7 @@ mod tests {
+ 
+     use std::error::Error;
+     use std::io::Write;
++    use std::os::unix::io::AsRawFd;
+ 
+     use nix::pty::{openpty, OpenptyResult};
+     use nix::unistd::close;
+@@ -186,7 +194,7 @@ mod tests {
      #[test]
      fn test_pty_equal_but_not_conflicting() -> Result<(), &'static str> {
          let OpenptyResult { master, slave } = openpty(None, None).expect("Could not open pty.");
@@ -18,23 +42,25 @@
              .map_err(|_| "Error creating UnixIdentifier from pty fd")
              .and_then(|ident| {
                  if !ident.eq(&ident) {
-@@ -196,7 +196,7 @@ mod tests {
+@@ -196,7 +204,7 @@ mod tests {
                      return Err("pty fd does not conflict with itself, but conflict detected");
                  }
  
 -                let second_ident = unsafe { UnixIdentifier::try_from_raw_fd(slave, false) }
-+                let second_ident = unsafe { UnixIdentifier::try_from_raw_fd(slave.as_raw_fd(), false) }
++                let second_ident = UnixIdentifier::try_from_owned_fd(slave)
                      .map_err(|_| "Error creating second Identifier to pty")?;
                  if !ident.eq(&second_ident) {
                      return Err("ident != second_ident");
-@@ -209,8 +209,8 @@ mod tests {
+@@ -209,12 +217,6 @@ mod tests {
                  Ok(())
              });
  
 -        let r1 = close(master);
 -        let r2 = close(slave);
-+        let r1 = close(master.as_raw_fd());
+-
-+        let r2 = close(slave.as_raw_fd());
+-        r1.expect("Error closing master end of pty");
- 
+-        r2.expect("Error closing slave end of pty");
-         r1.expect("Error closing master end of pty");
+-
-         r2.expect("Error closing slave end of pty");
+         res
+     }
+ }