Fix lint

client/ssh/server/winpty/conpty.go

@@ -4,6 +4,7 @@ package winpty
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
@@ -16,6 +17,10 @@ import (
 	"golang.org/x/sys/windows"
 )
 
+var (
+	ErrEmptyEnvironment = errors.New("empty environment")
+)
+
 const (
 	extendedStartupInfoPresent       = 0x00080000
 	createUnicodeEnvironment         = 0x00000400
@@ -277,7 +282,7 @@ func createConPtyProcess(commandLine string, userToken windows.Handle, userEnv [
 // convertEnvironmentToUTF16 converts environment variables to Windows UTF16 format.
 func convertEnvironmentToUTF16(userEnv []string) (*uint16, error) {
 	if len(userEnv) == 0 {
-		return nil, nil
+		return nil, ErrEmptyEnvironment
 	}
 
 	var envUTF16 []uint16
@@ -297,7 +302,7 @@ func convertEnvironmentToUTF16(userEnv []string) (*uint16, error) {
 	if len(envUTF16) > 0 {
 		return &envUTF16[0], nil
 	}
-	return nil, nil
+	return nil, ErrEmptyEnvironment
 }
 
 // duplicateToPrimaryToken converts an impersonation token to a primary token.

client/ssh/server/winpty/conpty_test.go

@@ -5,6 +5,7 @@ package winpty
 import (
 	"testing"
 
+	log "github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/sys/windows"
@@ -280,7 +281,9 @@ func BenchmarkConPtyCreation(b *testing.B) {
 		}
 
 		// Clean up
-		procClosePseudoConsole.Call(uintptr(hPty))
+		if ret, _, err := procClosePseudoConsole.Call(uintptr(hPty)); ret == 0 {
+			log.Debugf("ClosePseudoConsole failed: %v", err)
+		}
 		closeHandles(inputRead, inputWrite, outputRead, outputWrite)
 	}
 }