From f5d16cc4237e2f9eff19cd55978f0dd9aa7d81ef Mon Sep 17 00:00:00 2001
From: Alex Yatskov <alex@foosoft.net>
Date: Tue, 23 Jun 2015 18:27:16 +0900
Subject: [PATCH] Handle invalid versions better

---
 database.go | 9 +++++++--
 vfs.go      | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/database.go b/database.go
index b4267ba..5744b74 100644
--- a/database.go
+++ b/database.go
@@ -23,6 +23,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"path"
@@ -41,7 +42,7 @@ type database struct {
 	vers verList
 }
 
-func newDatabase(dir string, index int, writable bool) (*database, error) {
+func newDatabase(dir string, index uint, writable bool) (*database, error) {
 	db := &database{base: dir}
 	if err := db.load(dir, index, writable); err != nil {
 		return nil, err
@@ -50,7 +51,7 @@ func newDatabase(dir string, index int, writable bool) (*database, error) {
 	return db, nil
 }
 
-func (db *database) load(dir string, index int, writable bool) error {
+func (db *database) load(dir string, index uint, writable bool) error {
 	var err error
 
 	db.base, err = filepath.Abs(dir)
@@ -69,6 +70,10 @@ func (db *database) load(dir string, index int, writable bool) error {
 		return err
 	}
 
+	if index > uint(len(db.vers)) {
+		return errors.New("invalid version index")
+	}
+
 	if index > 0 {
 		db.vers = db.vers[:index]
 	}
diff --git a/vfs.go b/vfs.go
index dd36023..e39a8fe 100644
--- a/vfs.go
+++ b/vfs.go
@@ -40,7 +40,7 @@ func usage() {
 }
 
 func main() {
-	version := flag.Int("version", 0, "version index (specify 0 for latest)")
+	version := flag.Uint("version", 0, "version index (0 for head)")
 	readonly := flag.Bool("readonly", false, "mount filesystem as readonly")
 	flag.Usage = usage
 	flag.Parse()