update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/opencontainers/runc/libcontainer/user/user.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"os/user"
 	"strconv"
 	"strings"
 )
@@ -28,6 +29,28 @@ type User struct {
 	Shell string
 }
 
+// userFromOS converts an os/user.(*User) to local User
+//
+// (This does not include Pass, Shell or Gecos)
+func userFromOS(u *user.User) (User, error) {
+	newUser := User{
+		Name: u.Username,
+		Home: u.HomeDir,
+	}
+	id, err := strconv.Atoi(u.Uid)
+	if err != nil {
+		return newUser, err
+	}
+	newUser.Uid = id
+
+	id, err = strconv.Atoi(u.Gid)
+	if err != nil {
+		return newUser, err
+	}
+	newUser.Gid = id
+	return newUser, nil
+}
+
 type Group struct {
 	Name string
 	Pass string
@@ -35,6 +58,23 @@ type Group struct {
 	List []string
 }
 
+// groupFromOS converts an os/user.(*Group) to local Group
+//
+// (This does not include Pass, Shell or Gecos)
+func groupFromOS(g *user.Group) (Group, error) {
+	newGroup := Group{
+		Name: g.Name,
+	}
+
+	id, err := strconv.Atoi(g.Gid)
+	if err != nil {
+		return newGroup, err
+	}
+	newGroup.Gid = id
+
+	return newGroup, nil
+}
+
 func parseLine(line string, v ...interface{}) {
 	if line == "" {
 		return
@@ -199,18 +239,16 @@ type ExecUser struct {
 // files cannot be opened for any reason, the error is ignored and a nil
 // io.Reader is passed instead.
 func GetExecUserPath(userSpec string, defaults *ExecUser, passwdPath, groupPath string) (*ExecUser, error) {
-	passwd, err := os.Open(passwdPath)
-	if err != nil {
-		passwd = nil
-	} else {
-		defer passwd.Close()
+	var passwd, group io.Reader
+
+	if passwdFile, err := os.Open(passwdPath); err == nil {
+		passwd = passwdFile
+		defer passwdFile.Close()
 	}
 
-	group, err := os.Open(groupPath)
-	if err != nil {
-		group = nil
-	} else {
-		defer group.Close()
+	if groupFile, err := os.Open(groupPath); err == nil {
+		group = groupFile
+		defer groupFile.Close()
 	}
 
 	return GetExecUser(userSpec, defaults, passwd, group)
@@ -343,7 +381,7 @@ func GetExecUser(userSpec string, defaults *ExecUser, passwd, group io.Reader) (
 			if len(groups) > 0 {
 				// First match wins, even if there's more than one matching entry.
 				user.Gid = groups[0].Gid
-			} else if groupArg != "" {
+			} else {
 				// If we can't find a group with the given name, the only other valid
 				// option is if it's a numeric group name with no associated entry in group.
 
@@ -433,9 +471,11 @@ func GetAdditionalGroups(additionalGroups []string, group io.Reader) ([]int, err
 // that opens the groupPath given and gives it as an argument to
 // GetAdditionalGroups.
 func GetAdditionalGroupsPath(additionalGroups []string, groupPath string) ([]int, error) {
-	group, err := os.Open(groupPath)
-	if err == nil {
-		defer group.Close()
+	var group io.Reader
+
+	if groupFile, err := os.Open(groupPath); err == nil {
+		group = groupFile
+		defer groupFile.Close()
 	}
 	return GetAdditionalGroups(additionalGroups, group)
 }