Update loginshell to version with Windows support (#184)

Gopkg.lock

@@ -137,7 +137,7 @@
   branch = "master"
   name = "github.com/riywo/loginshell"
   packages = ["."]
-  revision = "5da3acff02554cee5e8ccb4651cc5a4072f41790"
+  revision = "c2f4167b23039c6289b5a488080176426ec5dad9"
 
 [[projects]]
   name = "github.com/stretchr/testify"

vendor/github.com/riywo/loginshell/loginshell.go

@@ -17,15 +17,29 @@ func Shell() (string, error) {
           return LinuxShell()
         case "darwin":
           return DarwinShell()
+        case "windows":
+          return WindowsShell()
     }
     return "", errors.New("Undefined GOOS: " + runtime.GOOS)
 }
 
+func WindowsShell() (string, error) {
+    consoleApp := os.Getenv("COMSPEC")
+    if consoleApp == "" {
+        consoleApp = "cmd.exe"
+    }
+    return consoleApp, nil
+}
+
 func LinuxShell() (string, error) {
     user, err := user.Current()
-    if err != nil { return "", err }
+    if err != nil {
+        return "", err
+    }
     out, err := exec.Command("getent", "passwd", user.Uid).Output()
-    if err != nil { return "", err }
+    if err != nil {
+        return "", err
+    }
 
     ent := strings.Split(strings.TrimSuffix(string(out), "\n"), ":")
     return ent[6], nil
@@ -34,11 +48,15 @@ func LinuxShell() (string, error) {
 func DarwinShell() (string, error) {
     dir := "Local/Default/Users/" + os.Getenv("USER")
     out, err := exec.Command("dscl", "localhost", "-read", dir, "UserShell").Output()
-    if err != nil { return "", err }
+    if err != nil {
+        return "", err
+    }
 
     re := regexp.MustCompile("UserShell: (/[^ ]+)\n")
     matched := re.FindStringSubmatch(string(out))
     shell := matched[1]
-    if shell == "" { return "", errors.New(fmt.Sprintf("Invalid output: %s", string(out))) }
+    if shell == "" {
+        return "", errors.New(fmt.Sprintf("Invalid output: %s", string(out)))
+    }
     return shell, nil
 }

vendor/github.com/riywo/loginshell/loginshell_test.go

@@ -4,6 +4,7 @@ import (
     "testing"
     "os"
     "fmt"
+    "runtime"
 )
 
 func TestShell(t *testing.T) {
@@ -12,8 +13,14 @@ func TestShell(t *testing.T) {
         t.Error(err)
     }
 
-    currentShell := os.Getenv("SHELL")
-    if shell != currentShell {
-        t.Error(fmt.Sprintf("Output: %s, Current login shell: %s", shell, currentShell))
+    if runtime.GOOS == "windows" {
+        if shell == "" {
+            t.Error("Output is empty!")
+        }
+    } else {
+        currentShell := os.Getenv("SHELL")
+        if shell != currentShell {
+            t.Error(fmt.Sprintf("Output: %s, Current login shell: %s", shell, currentShell))
+        }
     }
 }