Allow deregistration of handler

Implemented in both the server and client.
Renamed to client function to match the server side functions
Example progs need to be "ported" as this *is* an API change.

client.go

@@ -94,8 +94,22 @@ func (f HandlerQueryFunc) QueryDNS(w RequestWriter, r *Msg) {
 	go f(w, r)
 }
 
+// HandleQueryFunc registers the handler with the given pattern in the
+// DefaultQueryMux.
 func HandleQueryFunc(pattern string, handler func(RequestWriter, *Msg)) {
-	DefaultQueryMux.HandleQueryFunc(pattern, handler)
+	DefaultQueryMux.HandleFunc(pattern, handler)
+}
+
+// HandleQuery registers the handler
+// in the DefaultQueryMux
+func HandleQuery(pattern string, handler HandlerQueryFunc) {
+	DefaultQueryMux.Handle(pattern, handler)
+}
+
+// HandleQueryRemove deregisters the handle with the given pattern                                                                          
+// in the DefaultQueryMux.                                   
+func HandleQueryRemove(pattern string) {
+	DefaultQueryMux.HandleRemove(pattern)
 }
 
 // reusing zoneMatch from server.go
@@ -121,7 +135,13 @@ func (mux *QueryMux) Handle(pattern string, handler QueryHandler) {
 	mux.m[pattern] = handler
 }
 
-func (mux *QueryMux) HandleQueryFunc(pattern string, handler func(RequestWriter, *Msg)) {
+// HandleRemove deregisters the handler with given pattern.
+func (mux *QueryMux) HandleRemove(pattern string) {
+	delete(mux.m, pattern)
+}
+
+// HandleFunc ...
+func (mux *QueryMux) HandleFunc(pattern string, handler func(RequestWriter, *Msg)) {
 	mux.Handle(pattern, HandlerQueryFunc(handler))
 }
 

server.go

@@ -117,10 +117,6 @@ func (mux *ServeMux) Handle(pattern string, handler Handler) {
 	if pattern == "" {
 		panic("dns: invalid pattern " + pattern)
 	}
-	// Should this go
-	//if pattern[len(pattern)-1] != '.' { // no ending .
-	//	mux.m[pattern+"."] = handler
-	//} else {
 	mux.m[pattern] = handler
 }
 
@@ -128,6 +124,14 @@ func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Ms
 	mux.Handle(pattern, HandlerFunc(handler))
 }
 
+func (mux *ServeMux) HandleRemove(pattern string) {
+	if pattern == "" {
+		panic("dns: invalid pattern " + pattern)
+	}
+	// if its there, its gone
+	delete(mux.m, pattern)
+}
+
 // ServeDNS dispatches the request to the handler whose
 // pattern most closely matches the request message.
 func (mux *ServeMux) ServeDNS(w ResponseWriter, request *Msg) {
@@ -138,11 +142,17 @@ func (mux *ServeMux) ServeDNS(w ResponseWriter, request *Msg) {
 	h.ServeDNS(w, request)
 }
 
-// Handle register the handler the given pattern
+// Handle registers the handler with the given pattern
 // in the DefaultServeMux. The documentation for
 // ServeMux explains how patters are matched.
 func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
 
+// HandleRemove deregisters the handle with the given pattern
+// in the DefaultServeMux.
+func HandleRemove(pattern string) { DefaultServeMux.HandleRemove(pattern) }
+
+// HandleFunc registers the handler function with te given pattern
+// in the DefaultServeMux.
 func HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
 	DefaultServeMux.HandleFunc(pattern, handler)
 }
@@ -322,7 +332,7 @@ func (c *conn) serve() {
 				w.tsigStatus = ErrKeyAlg
 			}
 			w.tsigStatus = TsigVerify(c.request, w.conn.tsigSecret[secret], "", false)
-			w.tsigTimersOnly = false	// Will this ever be true?
+			w.tsigTimersOnly = false // Will this ever be true?
 			w.tsigRequestMAC = req.Extra[len(req.Extra)-1].(*RR_TSIG).MAC
 		}
 		w.req = req
@@ -340,7 +350,7 @@ func (c *conn) serve() {
 func (w *response) Write(m *Msg) (err error) {
 	var (
 		data []byte
-		ok bool
+		ok   bool
 	)
 	if m.IsTsig() {
 		data, w.tsigRequestMAC, err = TsigGenerate(m, w.conn.tsigSecret[m.Extra[len(m.Extra)-1].(*RR_TSIG).Hdr.Name], w.tsigRequestMAC, w.tsigTimersOnly)