From 3b4b168051fdf00e06a89505bce97369749a2587 Mon Sep 17 00:00:00 2001
From: Stefan Scherer <scherer_stefan@icloud.com>
Date: Wed, 13 Jan 2016 00:46:11 +0100
Subject: [PATCH] Check grand parent if not directly called from a windows
 shell

Signed-off-by: Stefan Scherer <scherer_stefan@icloud.com>
---
 libmachine/shell/shell_windows.go      | 28 +++++++++++++++++---------
 libmachine/shell/shell_windows_test.go | 22 +++++++++++++++++---
 2 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/libmachine/shell/shell_windows.go b/libmachine/shell/shell_windows.go
index e46c5681d9..89cd2c8b0a 100644
--- a/libmachine/shell/shell_windows.go
+++ b/libmachine/shell/shell_windows.go
@@ -37,24 +37,22 @@ func getProcessEntry(pid int) (pe *syscall.ProcessEntry32, err error) {
 	}
 }
 
-// startedBy returns the exe file name of the parent process.
-func startedBy() (exefile string, err error) {
-	ppid := os.Getppid()
-
-	pe, err := getProcessEntry(ppid)
+// getNameAndItsPpid returns the exe file name its parent process id.
+func getNameAndItsPpid(pid int) (exefile string, parentid int, err error) {
+	pe, err := getProcessEntry(pid)
 	if err != nil {
-		return "", err
+		return "", 0, err
 	}
 
 	name := syscall.UTF16ToString(pe.ExeFile[:])
-	return name, nil
+	return name, int(pe.ParentProcessID), nil
 }
 
 func Detect() (string, error) {
 	shell := os.Getenv("SHELL")
 
 	if shell == "" {
-		shell, err := startedBy()
+		shell, shellppid, err := getNameAndItsPpid(os.Getppid())
 		if err != nil {
 			return "cmd", err // defaulting to cmd
 		}
@@ -63,8 +61,18 @@ func Detect() (string, error) {
 		} else if strings.Contains(strings.ToLower(shell), "cmd") {
 			return "cmd", nil
 		} else {
-			fmt.Printf("You can further specify your shell with either 'cmd' or 'powershell' with the --shell flag.\n\n")
-			return "cmd", nil // this could be either powershell or cmd, defaulting to cmd
+			shell, _, err := getNameAndItsPpid(shellppid)
+			if err != nil {
+				return "cmd", err // defaulting to cmd
+			}
+			if strings.Contains(strings.ToLower(shell), "powershell") {
+				return "powershell", nil
+			} else if strings.Contains(strings.ToLower(shell), "cmd") {
+				return "cmd", nil
+			} else {
+				fmt.Printf("You can further specify your shell with either 'cmd' or 'powershell' with the --shell flag.\n\n")
+				return "cmd", nil // this could be either powershell or cmd, defaulting to cmd
+			}
 		}
 	}
 
diff --git a/libmachine/shell/shell_windows_test.go b/libmachine/shell/shell_windows_test.go
index 945ebc51b4..81c0c50705 100644
--- a/libmachine/shell/shell_windows_test.go
+++ b/libmachine/shell/shell_windows_test.go
@@ -13,13 +13,29 @@ func TestDetect(t *testing.T) {
 
 	shell, err := Detect()
 
-	assert.Equal(t, "cmd", shell)
+	assert.Equal(t, "powershell", shell)
 	assert.NoError(t, err)
 }
 
-func TestStartedBy(t *testing.T) {
-	shell, err := startedBy()
+func TestGetNameAndItsPpidOfCurrent(t *testing.T) {
+	shell, shellppid, err := getNameAndItsPpid(os.Getpid())
+
+	assert.Equal(t, "shell.test.exe", shell)
+	assert.Equal(t, os.Getppid(), shellppid)
+	assert.NoError(t, err)
+}
+
+func TestGetNameAndItsPpidOfParent(t *testing.T) {
+	shell, _, err := getNameAndItsPpid(os.Getppid())
 
 	assert.Equal(t, "go.exe", shell)
 	assert.NoError(t, err)
 }
+
+func TestGetNameAndItsPpidOfGrandParent(t *testing.T) {
+	shell, shellppid, err := getNameAndItsPpid(os.Getppid())
+	shell, shellppid, err = getNameAndItsPpid(shellppid)
+
+	assert.Equal(t, "powershell.exe", shell)
+	assert.NoError(t, err)
+}