From 82cfe822ff1265512935f06a94b74dd13e0f9a16 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Wed, 10 Oct 2012 12:39:45 +0200
Subject: [PATCH] Make toRadixName much faster

fix bug when a escape is escaped: \\. This last dot is now a real
domain label seperator dot.
---
 zone.go      | 19 +++++++++++++++----
 zone_test.go |  7 +++++--
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/zone.go b/zone.go
index b007ad52..00672dda 100644
--- a/zone.go
+++ b/zone.go
@@ -109,17 +109,28 @@ func NewZoneData(s string) *ZoneData {
 // we preserve the nsec ordering of the zone (this idea was stolen from NSD).
 // Each label is also lowercased. The name given must be fully qualified.
 func toRadixName(d string) string {
-	if d == "." {
+	if d == "" || d == "." {
 		return "."
 	}
 	s := ""
+	ld := len(d)
+	if d[ld-1] != '.' {
+		d = d + "."
+		ld++
+	}
 	var lastdot int
 	var lastbyte byte
 	var lastlastbyte byte
 	for i := 0; i < len(d); i++ {
-		if d[i] == '.' && lastbyte != '\\' && lastlastbyte != '\\' {
-			s = d[lastdot:i] + "." + s
-			lastdot = i+1
+		if d[i] == '.' {
+			switch {
+			case lastbyte != '\\':
+				fallthrough
+			case lastbyte == '\\' && lastlastbyte == '\\':
+				s = d[lastdot:i] + "." + s
+				lastdot = i + 1
+				continue
+			}
 		}
 		lastlastbyte = lastbyte
 		lastbyte = d[i]
diff --git a/zone_test.go b/zone_test.go
index c2306a24..7f15a6a5 100644
--- a/zone_test.go
+++ b/zone_test.go
@@ -7,9 +7,12 @@ import (
 func TestRadixName(t *testing.T) {
 	tests := map[string]string{".": ".",
 		"www.miek.nl.": ".nl.miek.www",
-		"miek.nl.": ".nl.miek",
-		"mi\\.ek.nl.": ".nl.mi\\.ek",}
+		"miek.nl.":     ".nl.miek",
+		"mi\\.ek.nl.":  ".nl.mi\\.ek",
+		`mi\\.ek.nl.`:  `.nl.ek.mi\\`,
+		"":             "."}
 	for i, o := range tests {
+		t.Logf("%s %v\n", i, SplitLabels(i))
 		if x := toRadixName(i); x != o {
 			t.Logf("%s should convert to %s, not %s\n", i, o, x)
 			t.Fail()