vbatts/tar-split
1
0
Fork 0
forked from mirrors/tar-split
Code Releases Activity

archive/tar: properly format GNU base-256 encoding

Browse source 
Motivation:
* Previous implementation silently failed when an integer overflow
occurred. Now, we report an ErrFieldTooLong.
* Previous implementation did not encode in two's complement format and was
unable to encode negative numbers.

The relevant GNU specification says:
<<<
GNU format uses two's-complement base-256 notation to store values
that do not fit into standard ustar range.
>>>

Fixes #12436

Change-Id: I09c20602eabf8ae3a7e0db35b79440a64bfaf807
Reviewed-on: https://go-review.googlesource.com/17425
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Joe Tsai 2015-12-02 15:48:06 -08:00 • committed by Vincent Batts
parent be9ac88117
commit ce5aac17f9
2 changed files with 105 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

83
archive/tar/writer_test.go
View file

@ -9,6 +9,7 @@ import (
"fmt"
"io"
"io/ioutil"
"math"
"os"
"reflect"
"sort"
@ -637,3 +638,85 @@ func TestFormatPAXRecord(t *testing.T) {
}
}
}
func TestFitsInBase256(t *testing.T) {
var vectors = []struct {
input int64
width int
ok bool
}{
{+1, 8, true},
{0, 8, true},
{-1, 8, true},
{1 << 56, 8, false},
{(1 << 56) - 1, 8, true},
{-1 << 56, 8, true},
{(-1 << 56) - 1, 8, false},
{121654, 8, true},
{-9849849, 8, true},
{math.MaxInt64, 9, true},
{0, 9, true},
{math.MinInt64, 9, true},
{math.MaxInt64, 12, true},
{0, 12, true},
{math.MinInt64, 12, true},
}
for _, v := range vectors {
ok := fitsInBase256(v.width, v.input)
if ok != v.ok {
t.Errorf("checkNumeric(%d, %d): got %v, want %v", v.input, v.width, ok, v.ok)
}
}
}
func TestFormatNumeric(t *testing.T) {
var vectors = []struct {
input int64
output string
ok bool
}{
// Test base-256 (binary) encoded values.
{-1, "\xff", true},
{-1, "\xff\xff", true},
{-1, "\xff\xff\xff", true},
{(1 << 0), "0", false},
{(1 << 8) - 1, "\x80\xff", true},
{(1 << 8), "0\x00", false},
{(1 << 16) - 1, "\x80\xff\xff", true},
{(1 << 16), "00\x00", false},
{-1 * (1 << 0), "\xff", true},
{-1*(1<<0) - 1, "0", false},
{-1 * (1 << 8), "\xff\x00", true},
{-1*(1<<8) - 1, "0\x00", false},
{-1 * (1 << 16), "\xff\x00\x00", true},
{-1*(1<<16) - 1, "00\x00", false},
{537795476381659745, "0000000\x00", false},
{537795476381659745, "\x80\x00\x00\x00\x07\x76\xa2\x22\xeb\x8a\x72\x61", true},
{-615126028225187231, "0000000\x00", false},
{-615126028225187231, "\xff\xff\xff\xff\xf7\x76\xa2\x22\xeb\x8a\x72\x61", true},
{math.MaxInt64, "0000000\x00", false},
{math.MaxInt64, "\x80\x00\x00\x00\x7f\xff\xff\xff\xff\xff\xff\xff", true},
{math.MinInt64, "0000000\x00", false},
{math.MinInt64, "\xff\xff\xff\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
{math.MaxInt64, "\x80\x7f\xff\xff\xff\xff\xff\xff\xff", true},
{math.MinInt64, "\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
}
for _, v := range vectors {
var f formatter
output := make([]byte, len(v.output))
f.formatNumeric(output, v.input)
ok := (f.err == nil)
if ok != v.ok {
if v.ok {
t.Errorf("formatNumeric(%d): got formatting failure, want success", v.input)
} else {
t.Errorf("formatNumeric(%d): got formatting success, want failure", v.input)
}
}
if string(output) != v.output {
t.Errorf("formatNumeric(%d): got %q, want %q", v.input, output, v.output)
}
}
}