From 5de44ba4d6a222a8d4b35234443180ec933b7dd1 Mon Sep 17 00:00:00 2001
From: stephen mcquay <stephen@mcquay.me>
Date: Wed, 2 Mar 2016 22:06:17 -0800
Subject: [PATCH] tighter constraints on allowed paths.

Change-Id: Ie6b121e4733e45288a36dbc2426f556fd5e2832d
---
 storage.go   |  2 +-
 vain_test.go | 36 +++++++++++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/storage.go b/storage.go
index 15baf78..aa2840d 100644
--- a/storage.go
+++ b/storage.go
@@ -12,7 +12,7 @@ import (
 // Valid checks that p will not confuse the go tool if added to packages.
 func Valid(p string, packages []Package) bool {
 	for _, pkg := range packages {
-		if strings.HasPrefix(pkg.path, p) {
+		if strings.HasPrefix(pkg.path, p) || strings.HasPrefix(p, pkg.path) {
 			return false
 		}
 	}
diff --git a/vain_test.go b/vain_test.go
index 202993a..a7a7ed5 100644
--- a/vain_test.go
+++ b/vain_test.go
@@ -53,13 +53,6 @@ func TestValid(t *testing.T) {
 			in:   "bobo",
 			want: true,
 		},
-		{
-			pkgs: []Package{
-				{path: ""},
-			},
-			in:   "bobo",
-			want: true,
-		},
 		{
 			pkgs: []Package{
 				{path: "bobo"},
@@ -74,6 +67,35 @@ func TestValid(t *testing.T) {
 			in:   "a/b/c",
 			want: false,
 		},
+		{
+			pkgs: []Package{
+				{path: "a/b/c"},
+			},
+			in:   "a/b",
+			want: false,
+		},
+		{
+			pkgs: []Package{
+				{path: "name/db"},
+				{path: "name/lib"},
+			},
+			in:   "name/foo",
+			want: true,
+		},
+		{
+			pkgs: []Package{
+				{path: "a"},
+			},
+			in:   "a/b",
+			want: false,
+		},
+		{
+			pkgs: []Package{
+				{path: "foo"},
+			},
+			in:   "foo/bar",
+			want: false,
+		},
 		{
 			pkgs: []Package{
 				{path: "foo/bar"},