Added MG_WS_HANDSHAKE

mongoose.c

@@ -2631,8 +2631,10 @@ static void send_websocket_handshake_if_requested(struct mg_connection *conn) {
         *key = mg_get_header(conn, "Sec-WebSocket-Key");
   if (ver != NULL && key != NULL) {
     conn->is_websocket = 1;
+    if (call_user(MG_CONN_2_CONN(conn), MG_WS_HANDSHAKE) == MG_FALSE) {
       send_websocket_handshake(conn, key);
     }
+  }
 }
 
 static void ping_idle_websocket_connection(struct connection *conn, time_t t) {

mongoose.h

@@ -67,7 +67,7 @@ enum mg_event {
   MG_REQUEST,     // If callback returns MG_FALSE, Mongoose continues with req
   MG_REPLY,       // If callback returns MG_FALSE, Mongoose closes connection
   MG_CLOSE,       // Connection is closed, callback return value is ignored
-  MG_LUA,         // Called before LSP page invoked
+  MG_WS_HANDSHAKE,  // New websocket connection, handshake request
   MG_HTTP_ERROR   // If callback returns MG_FALSE, Mongoose continues with err
 };
 typedef int (*mg_handler_t)(struct mg_connection *, enum mg_event);