code review 5853044: os: add missing byte to FileMode buffer

src/pkg/os/types.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package os
 
 import (
         "syscall"
         "time"
 )
@@ skipping 40 matching lines @@
         ModeSticky                                     // t: sticky
 
         // Mask for the type bits. For regular files, none will be set.
         ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice
 
         ModePerm FileMode = 0777 // permission bits
 )
 
 func (m FileMode) String() string {
         const str = "dalTLDpSugct"
-        const rwx = "rwxrwxrwx"
-        var buf [len(str) + len(rwx)]byte
+        var buf [32]byte // Mode is uint32.
         w := 0
         for i, c := range str {
                 if m&(1<<uint(32-1-i)) != 0 {
                         buf[w] = byte(c)
                         w++
                 }
         }
         if w == 0 {
                 buf[w] = '-'
                 w++
         }
+        const rwx = "rwxrwxrwx"
         for i, c := range rwx {
                 if m&(1<<uint(9-1-i)) != 0 {
                         buf[w] = byte(c)
                 } else {
                         buf[w] = '-'
                 }
                 w++
         }
         return string(buf[:w])
 }
@@ skipping 32 matching lines @@
 // SameFile only applies to results returned by this package's Stat.
 // It returns false in other cases.
 func SameFile(fi1, fi2 FileInfo) bool {
         fs1, ok1 := fi1.(*fileStat)
         fs2, ok2 := fi2.(*fileStat)
         if !ok1 || !ok2 {
                 return false
         }
         return sameFile(fs1.sys, fs2.sys)
 }