From 5de99cd3905068da9a597d1de6b155448e53fde4 Mon Sep 17 00:00:00 2001
From: Aleksa Sarai <asarai@suse.de>
Date: Fri, 21 Sep 2018 11:55:36 +1000
Subject: [PATCH] tty: clean up epollConsole closing

ec0d23a92ffe ("tty: close epollConsole on errors") fixed a significant
issue, but the cleanup was not ideal (especially if the function is
changed in future to add additional error conditions to those currently
present). Using the defer-named-error trick avoids this issue and makes
the code more readable.

Signed-off-by: Aleksa Sarai <asarai@suse.de>
---
 tty.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tty.go b/tty.go
index 70ebc6bdc..6106c2db3 100644
--- a/tty.go
+++ b/tty.go
@@ -71,7 +71,7 @@ func inheritStdio(process *libcontainer.Process) error {
 	return nil
 }
 
-func (t *tty) recvtty(process *libcontainer.Process, socket *os.File) error {
+func (t *tty) recvtty(process *libcontainer.Process, socket *os.File) (Err error) {
 	f, err := utils.RecvFd(socket)
 	if err != nil {
 		return err
@@ -89,6 +89,11 @@ func (t *tty) recvtty(process *libcontainer.Process, socket *os.File) error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		if Err != nil {
+			epollConsole.Close()
+		}
+	}()
 	go epoller.Wait()
 	go io.Copy(epollConsole, os.Stdin)
 	t.wg.Add(1)
@@ -97,11 +102,9 @@ func (t *tty) recvtty(process *libcontainer.Process, socket *os.File) error {
 	// set raw mode to stdin and also handle interrupt
 	stdin, err := console.ConsoleFromFile(os.Stdin)
 	if err != nil {
-		epollConsole.Close()
 		return err
 	}
 	if err := stdin.SetRaw(); err != nil {
-		epollConsole.Close()
 		return fmt.Errorf("failed to set the terminal from the stdin: %v", err)
 	}
 	go handleInterrupt(stdin)