From cd53ec524410020db312089f2623b1a50f30121e Mon Sep 17 00:00:00 2001
From: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Date: Fri, 27 May 2016 02:47:32 +0000
Subject: [PATCH] Fix filepath.Walk misusage in pkg/directory

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
---
 pkg/directory/directory_test.go    |  7 +++++++
 pkg/directory/directory_unix.go    | 11 ++++++++++-
 pkg/directory/directory_windows.go | 11 ++++++++++-
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/pkg/directory/directory_test.go b/pkg/directory/directory_test.go
index 4611062848..2b7a4657be 100644
--- a/pkg/directory/directory_test.go
+++ b/pkg/directory/directory_test.go
@@ -183,3 +183,10 @@ func TestMoveToSubdir(t *testing.T) {
 		t.Fatalf("Results after migration do not equal list of files: expected: %v, got: %v", filesList, results)
 	}
 }
+
+// Test a non-existing directory
+func TestSizeNonExistingDirectory(t *testing.T) {
+	if _, err := Size("/thisdirectoryshouldnotexist/TestSizeNonExistingDirectory"); err == nil {
+		t.Fatalf("error is expected")
+	}
+}
diff --git a/pkg/directory/directory_unix.go b/pkg/directory/directory_unix.go
index b43c79fb85..397251bdb8 100644
--- a/pkg/directory/directory_unix.go
+++ b/pkg/directory/directory_unix.go
@@ -11,7 +11,16 @@ import (
 // Size walks a directory tree and returns its total size in bytes.
 func Size(dir string) (size int64, err error) {
 	data := make(map[uint64]struct{})
-	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, e error) error {
+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, err error) error {
+		if err != nil {
+			// if dir does not exist, Size() returns the error.
+			// if dir/x disappeared while walking, Size() ignores dir/x.
+			if os.IsNotExist(err) && d != dir {
+				return nil
+			}
+			return err
+		}
+
 		// Ignore directory sizes
 		if fileInfo == nil {
 			return nil
diff --git a/pkg/directory/directory_windows.go b/pkg/directory/directory_windows.go
index 7a9f8cb68c..6fb0917c4c 100644
--- a/pkg/directory/directory_windows.go
+++ b/pkg/directory/directory_windows.go
@@ -9,7 +9,16 @@ import (
 
 // Size walks a directory tree and returns its total size in bytes.
 func Size(dir string) (size int64, err error) {
-	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, e error) error {
+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, err error) error {
+		if err != nil {
+			// if dir does not exist, Size() returns the error.
+			// if dir/x disappeared while walking, Size() ignores dir/x.
+			if os.IsNotExist(err) && d != dir {
+				return nil
+			}
+			return err
+		}
+
 		// Ignore directory sizes
 		if fileInfo == nil {
 			return nil