Merge branch 'develop' of https://github.com/astaxie/beego into develop

@@ -75,12 +75,6 @@ func (cs *CouchbaseSessionStore) SessionID() string {
 func (cs *CouchbaseSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer cs.b.Close()
 
-	// if rs.values is empty, return directly
-	if len(cs.values) < 1 {
-		cs.b.Delete(cs.sid)
-		return
-	}
-
 	bo, err := session.EncodeGob(cs.values)
 	if err != nil {
 		return

@@ -72,11 +72,6 @@ func (rs *MemcacheSessionStore) SessionID() string {
 // save session values to redis
 func (rs *MemcacheSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer rs.c.Close()
-	// if rs.values is empty, return directly
-	if len(rs.values) < 1 {
-		rs.c.Delete(rs.sid)
-		return
-	}
 
 	b, err := session.EncodeGob(rs.values)
 	if err != nil {

@@ -81,12 +81,6 @@ func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	c := rs.p.Get()
 	defer c.Close()
 
-	// if rs.values is empty, return directly
-	if len(rs.values) < 1 {
-		c.Do("DEL", rs.sid)
-		return
-	}
-
 	b, err := session.EncodeGob(rs.values)
 	if err != nil {
 		return

@@ -27,11 +27,14 @@ func serverStaticRouter(ctx *context.Context) {
 		if len(prefix) == 0 {
 			continue
 		}
-		if requestPath == "/favicon.ico" {
+		if requestPath == "/favicon.ico" || requestPath == "/robots.txt" {
 			file := path.Join(staticDir, requestPath)
 			if utils.FileExists(file) {
 				http.ServeFile(ctx.ResponseWriter, ctx.Request, file)
 				return
+			} else {
+				http.NotFound(ctx.ResponseWriter, ctx.Request)
+				return
 			}
 		}
 		if strings.HasPrefix(requestPath, prefix) {