do not allow empty database name, closes #1950

database.go

@@ -81,6 +81,10 @@ func (db *database) UnmarshalJSON(data []byte) error {
 		return err
 	}
 
+	if o.Name == "" {
+		return ErrDatabaseNameRequired
+	}
+
 	// Copy over properties from intermediate type.
 	db.name = o.Name
 	db.defaultRetentionPolicy = o.DefaultRetentionPolicy

server.go

@@ -747,6 +747,9 @@ func (s *Server) Databases() (a []string) {
 
 // CreateDatabase creates a new database.
 func (s *Server) CreateDatabase(name string) error {
+	if name == "" {
+		return ErrDatabaseNameRequired
+	}
 	c := &createDatabaseCommand{Name: name}
 	_, err := s.broadcast(createDatabaseMessageType, c)
 	return err

server_test.go

@@ -290,6 +290,11 @@ func TestServer_CreateDatabase(t *testing.T) {
 	s := OpenServer(NewMessagingClient())
 	defer s.Close()
 
+	// Attempt creating empty name database.
+	if err := s.CreateDatabase(""); err != influxdb.ErrDatabaseNameRequired {
+		t.Fatal("expected error on empty database name")
+	}
+
 	// Create the "foo" database.
 	if err := s.CreateDatabase("foo"); err != nil {
 		t.Fatal(err)