Merge #1290

1290: use subordinate terminal device for termios calls r=asomers a=jclulow

The pseudo-terminal device handling tests in some places make
tcgetattr(3C) and tcsetattr(3C) calls using the control/manager file
descriptor rather than the subordinate terminal descriptor.  This works
on some systems, but not all; others such as illumos (and presumably
Solaris) are more strict and require the termios requests be made
against the terminal descriptor only.

Co-authored-by: Joshua M. Clulow <jmc@oxide.computer>

test/sys/test_termios.rs

@@ -22,7 +22,7 @@ fn test_tcgetattr_pty() {
     let _m = crate::PTSNAME_MTX.lock().expect("Mutex got poisoned by another test");
 
     let pty = openpty(None, None).expect("openpty failed");
-    assert!(termios::tcgetattr(pty.master).is_ok());
+    assert!(termios::tcgetattr(pty.slave).is_ok());
     close(pty.master).expect("closing the master failed");
     close(pty.slave).expect("closing the slave failed");
 }
@@ -53,7 +53,7 @@ fn test_output_flags() {
         let pty = openpty(None, None).expect("openpty failed");
         assert!(pty.master > 0);
         assert!(pty.slave > 0);
-        let termios = tcgetattr(pty.master).expect("tcgetattr failed");
+        let termios = tcgetattr(pty.slave).expect("tcgetattr failed");
         close(pty.master).unwrap();
         close(pty.slave).unwrap();
         termios
@@ -95,7 +95,7 @@ fn test_local_flags() {
         let pty = openpty(None, None).unwrap();
         assert!(pty.master > 0);
         assert!(pty.slave > 0);
-        let termios = tcgetattr(pty.master).unwrap();
+        let termios = tcgetattr(pty.slave).unwrap();
         close(pty.master).unwrap();
         close(pty.slave).unwrap();
         termios

test/test_pty.rs

@@ -205,7 +205,7 @@ fn test_openpty_with_termios() {
         let pty = openpty(None, None).unwrap();
         assert!(pty.master > 0);
         assert!(pty.slave > 0);
-        let termios = tcgetattr(pty.master).unwrap();
+        let termios = tcgetattr(pty.slave).unwrap();
         close(pty.master).unwrap();
         close(pty.slave).unwrap();
         termios