From 15e8c75e0b21dcbc26057dc71196ab13150d4295 Mon Sep 17 00:00:00 2001
From: Elliot Morrison-Reed <elliotmr@gmail.com>
Date: Thu, 25 Aug 2016 23:06:56 +0200
Subject: [PATCH] Changed string comparison for child path to use filepath.Rel

---
 cobra/cmd/helpers.go      | 15 ++++++++++++++-
 cobra/cmd/helpers_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/cobra/cmd/helpers.go b/cobra/cmd/helpers.go
index 7cd3be18..2c08dc1b 100644
--- a/cobra/cmd/helpers.go
+++ b/cobra/cmd/helpers.go
@@ -100,13 +100,26 @@ func guessCmdDir() string {
 func guessImportPath() string {
 	guessProjectPath()
 
-	if !strings.HasPrefix(projectPath, getSrcPath()) {
+	if !inPath(getSrcPath(), projectPath) {
 		er("Cobra only supports project within $GOPATH")
 	}
 
 	return filepath.ToSlash(filepath.Clean(strings.TrimPrefix(projectPath, getSrcPath())))
 }
 
+func inPath(srcPath, projectPath string) bool {
+	relPath, err := filepath.Rel(srcPath, projectPath)
+	if err != nil {
+		return false
+	}
+	for _, d := range filepath.SplitList(relPath) {
+		if d == ".." || d == "." {
+			return false
+		}
+	}
+	return true
+}
+
 func getSrcPath() string {
 	return filepath.Join(os.Getenv("GOPATH"), "src") + string(os.PathSeparator)
 }
diff --git a/cobra/cmd/helpers_test.go b/cobra/cmd/helpers_test.go
index bd0f7595..668850f1 100644
--- a/cobra/cmd/helpers_test.go
+++ b/cobra/cmd/helpers_test.go
@@ -38,3 +38,28 @@ func TestProjectPath(t *testing.T) {
 	checkGuess(t, "/bar/foo/commands", "", filepath.Join("/", "bar", "foo"))
 	checkGuess(t, "github.com/spf13/hugo/../hugo", "", filepath.Join("github.com", "spf13", "hugo"))
 }
+
+func TestInPath(t *testing.T) {
+	cases := []struct {
+		Src    string
+		Prj    string
+		InPath bool
+	}{
+		{"/bar/foo", "/bar/foo", false},
+		{"/bar/foo", "/bar/foo/baz", true},
+		{"/bar/foo/baz", "/bar/foo", false},
+		{"C:/bar/foo", "c:/bar/foo/baz", true},
+		{"c:\\bar\\foo", "C:\\bar\\foo", false},
+		{"c:\\bar\\..\\bar\\foo", "C:\\bar\\foo\\baz", true},
+	}
+	for _, tc := range cases {
+		ip := inPath(tc.Src, tc.Prj)
+		if tc.InPath != ip {
+			if tc.InPath {
+				t.Errorf("Unexpected %s determined as inside %s", tc.Prj, tc.Src)
+			} else {
+				t.Errorf("Unexpected %s not determined as inside %s", tc.Prj, tc.Src)
+			}
+		}
+	}
+}