Test invoking websocket with invalid utf-8

src/it/php/web/unittest/IntegrationTest.class.php

@@ -1,6 +1,7 @@
 <?php namespace web\unittest;
 
-use test\{Assert, After, Test, Values};
+use peer\ProtocolException;
+use test\{Assert, After, Expect, Test, Values};
 use util\Bytes;
 use websocket\WebSocket;
 
@@ -178,6 +179,18 @@ public function websocket_message($input, $output) {
     Assert::equals($output, $result);
   }
 
+  #[Test, Expect(class: ProtocolException::class, message: 'Connection closed (#1007): Not valid utf-8')]
+  public function invalid_utf8_passed_to_websocket_text_message() {
+    try {
+      $ws= new WebSocket($this->server->connection, '/ws');
+      $ws->connect();
+      $ws->send("\xfc");
+      $ws->receive();
+    } finally {
+      $ws->close();
+    }
+  }
+
   #[After]
   public function shutdown() {
     $this->server->shutdown();

src/main/php/xp/web/srv/WsProtocol.class.php

@@ -54,7 +54,7 @@ public function handleData($socket) {
         switch ($opcode) {
           case Opcodes::TEXT:
             if (!preg_match('//u', $payload)) {
-              $conn->answer(Opcodes::CLOSE, pack('n', 1007));
+              $conn->answer(Opcodes::CLOSE, pack('na*', 1007, 'Not valid utf-8'));
               $hints= ['error' => new FormatException('Malformed payload')];
               $socket->close();
               break;