unicode/utf8: use builtin max function to simplify code

Change-Id: I6a73b645d074baaa4d09480bdf4192816a8c2450
GitHub-Last-Rev: 202d498eb019c18b9ba30bccc2cb169c9eb79366
GitHub-Pull-Request: golang/go#71945
Reviewed-on: https://go-review.googlesource.com/c/go/+/652177
Auto-Submit: Keith Randall <khr@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

diff --git a/src/unicode/utf8/utf8.go b/src/unicode/utf8/utf8.go
index 180c008ed5b05eeb7b7a96a8aa89ba4cff68743c..82fa7c0d4d39d46d07f33634ca1fd2bed644d7eb 100644 (file)
--- a/src/unicode/utf8/utf8.go
+++ b/src/unicode/utf8/utf8.go
@@ -263,10 +263,7 @@ func DecodeLastRune(p []byte) (r rune, size int) {
        // guard against O(n^2) behavior when traversing
        // backwards through strings with long sequences of
        // invalid UTF-8.
-       lim := end - UTFMax
-       if lim < 0 {
-               lim = 0
-       }
+       lim := max(end - UTFMax, 0)
        for start--; start >= lim; start-- {
                if RuneStart(p[start]) {
                        break
@@ -303,10 +300,7 @@ func DecodeLastRuneInString(s string) (r rune, size int) {
        // guard against O(n^2) behavior when traversing
        // backwards through strings with long sequences of
        // invalid UTF-8.
-       lim := end - UTFMax
-       if lim < 0 {
-               lim = 0
-       }
+       lim := max(end - UTFMax, 0)
        for start--; start >= lim; start-- {
                if RuneStart(s[start]) {
                        break