Hold all entries sorted case-insensitively until just before sending, when we re-sort case-sensitively in Encode()

nameserver/entry.go

@@ -233,8 +233,8 @@ type GossipData struct {
 }
 
 func (g *GossipData) Merge(o router.GossipData) {
-	checkAndPanic(CaseSensitive(g.Entries))
-	defer func() { checkAndPanic(CaseSensitive(g.Entries)) }()
+	checkAndPanic(CaseInsensitive(g.Entries))
+	defer func() { checkAndPanic(CaseInsensitive(g.Entries)) }()
 	other := o.(*GossipData)
 	g.Entries.merge(other.Entries)
 	if g.Timestamp < other.Timestamp {
@@ -243,9 +243,12 @@ func (g *GossipData) Merge(o router.GossipData) {
 }
 
 func (g *GossipData) Encode() [][]byte {
-	checkAndPanic(CaseSensitive(g.Entries))
+	// Make a copy so we can sort: all outgoing data is sent in case-sensitive order
+	g2 := GossipData{Timestamp: g.Timestamp, Entries: make(Entries, len(g.Entries))}
+	copy(g2.Entries, g.Entries)
+	sort.Sort(CaseSensitive(g2.Entries))
 	buf := &bytes.Buffer{}
-	if err := gob.NewEncoder(buf).Encode(g); err != nil {
+	if err := gob.NewEncoder(buf).Encode(g2); err != nil {
 		panic(err)
 	}
 	return [][]byte{buf.Bytes()}

nameserver/nameserver.go

@@ -196,7 +196,6 @@ func (n *Nameserver) Gossip() router.GossipData {
 		Timestamp: now(),
 	}
 	copy(gossip.Entries, n.entries)
-	sort.Sort(CaseSensitive(gossip.Entries))
 	return gossip
 }