encoding/asn1: simplify appendFourDigits

The new code does not need a for-loop and is easier to read.

Change-Id: Ic182d63c4779c2179b721fcfaec362681284cc16
GitHub-Last-Rev: b3ee265df7eb4d51c945bf5453eb1b09f91912d9
GitHub-Pull-Request: golang/go#63879
Reviewed-on: https://go-review.googlesource.com/c/go/+/538721
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/encoding/asn1/marshal.go b/src/encoding/asn1/marshal.go
index d8c8fe17b374afa2eb5370c4b63d00e1aafa62cd..69ab4f6f9e81cc4ab9c23f5e1c1da18e1ed4b1e9 100644 (file)
--- a/src/encoding/asn1/marshal.go
+++ b/src/encoding/asn1/marshal.go
@@ -355,12 +355,11 @@ func appendTwoDigits(dst []byte, v int) []byte {
 }
 
 func appendFourDigits(dst []byte, v int) []byte {
-       var bytes [4]byte
-       for i := range bytes {
-               bytes[3-i] = '0' + byte(v%10)
-               v /= 10
-       }
-       return append(dst, bytes[:]...)
+       return append(dst,
+               byte('0'+(v/1000)%10),
+               byte('0'+(v/100)%10),
+               byte('0'+(v/10)%10),
+               byte('0'+v%10))
 }
 
 func outsideUTCRange(t time.Time) bool {