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util/cmpver: only consider ascii numerals (#9741)

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Fixes #9740

Signed-off-by: Paul Scott <paul@tailscale.com>
This commit is contained in:
Paul Scott
2023-10-11 13:42:32 +01:00
committed by GitHub
parent 78a083e144
commit 4e083e4548
2 changed files with 31 additions and 12 deletions
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19
util/cmpver/version.go
View File

@ -22,15 +22,20 @@ import (
"fmt" "fmt"
"strconv" "strconv"
"strings" "strings"
"unicode"
) )
func isnum(r rune) bool {
return r >= '0' && r <= '9'
}
func notnum(r rune) bool {
return !isnum(r)
}
// Compare returns an integer comparing two strings as version // Compare returns an integer comparing two strings as version
// numbers. The result will be 0 if v1==v2, -1 if v1 < v2, and +1 if // numbers. The result will be 0 if v1==v2, -1 if v1 < v2, and +1 if
// v1 > v2. // v1 > v2.
func Compare(v1, v2 string) int { func Compare(v1, v2 string) int {
notNumber := func(r rune) bool { return !unicode.IsNumber(r) }
var ( var (
f1, f2 string f1, f2 string
n1, n2 uint64 n1, n2 uint64
@ -38,16 +43,16 @@ func Compare(v1, v2 string) int {
) )
for v1 != "" || v2 != "" { for v1 != "" || v2 != "" {
// Compare the non-numeric character run lexicographically. // Compare the non-numeric character run lexicographically.
f1, v1 = splitPrefixFunc(v1, notNumber) f1, v1 = splitPrefixFunc(v1, notnum)
f2, v2 = splitPrefixFunc(v2, notNumber) f2, v2 = splitPrefixFunc(v2, notnum)
if res := strings.Compare(f1, f2); res != 0 { if res := strings.Compare(f1, f2); res != 0 {
return res return res
} }
// Compare the numeric character run numerically. // Compare the numeric character run numerically.
f1, v1 = splitPrefixFunc(v1, unicode.IsNumber) f1, v1 = splitPrefixFunc(v1, isnum)
f2, v2 = splitPrefixFunc(v2, unicode.IsNumber) f2, v2 = splitPrefixFunc(v2, isnum)
// ParseUint refuses to parse empty strings, which would only // ParseUint refuses to parse empty strings, which would only
// happen if we reached end-of-string. We follow the Debian // happen if we reached end-of-string. We follow the Debian

24
util/cmpver/version_test.go
View File

@ -1,9 +1,13 @@
// Copyright (c) Tailscale Inc & AUTHORS // Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause // SPDX-License-Identifier: BSD-3-Clause
package cmpver package cmpver_test
import "testing" import (
"testing"
"tailscale.com/util/cmpver"
)
func TestCompare(t *testing.T) { func TestCompare(t *testing.T) {
tests := []struct { tests := []struct {
@ -87,6 +91,16 @@ func TestCompare(t *testing.T) {
v2: "0.96-105", v2: "0.96-105",
want: 1, want: 1,
}, },
{
// Though ۱ and ۲ both satisfy unicode.IsNumber, our previous use
// of strconv.ParseUint with these characters would have lead us to
// panic. We're now only looking at ascii numbers, so test these are
// compared as text.
name: "only ascii numbers",
v1: "۱۱", // 2x EXTENDED ARABIC-INDIC DIGIT ONE
v2: "۲", // 1x EXTENDED ARABIC-INDIC DIGIT TWO
want: -1,
},
// A few specific OS version tests below. // A few specific OS version tests below.
{ {
@ -147,17 +161,17 @@ func TestCompare(t *testing.T) {
for _, test := range tests { for _, test := range tests {
t.Run(test.name, func(t *testing.T) { t.Run(test.name, func(t *testing.T) {
got := Compare(test.v1, test.v2) got := cmpver.Compare(test.v1, test.v2)
if got != test.want { if got != test.want {
t.Errorf("Compare(%v, %v) = %v, want %v", test.v1, test.v2, got, test.want) t.Errorf("Compare(%v, %v) = %v, want %v", test.v1, test.v2, got, test.want)
} }
// Reversing the comparison should reverse the outcome. // Reversing the comparison should reverse the outcome.
got2 := Compare(test.v2, test.v1) got2 := cmpver.Compare(test.v2, test.v1)
if got2 != -test.want { if got2 != -test.want {
t.Errorf("Compare(%v, %v) = %v, want %v", test.v2, test.v1, got2, -test.want) t.Errorf("Compare(%v, %v) = %v, want %v", test.v2, test.v1, got2, -test.want)
} }
// Check that version comparison does not allocate. // Check that version comparison does not allocate.
if n := testing.AllocsPerRun(100, func() { Compare(test.v1, test.v2) }); n > 0 { if n := testing.AllocsPerRun(100, func() { cmpver.Compare(test.v1, test.v2) }); n > 0 {
t.Errorf("Compare(%v, %v) got %v allocs per run", test.v1, test.v2, n) t.Errorf("Compare(%v, %v) got %v allocs per run", test.v1, test.v2, n)
} }
}) })