message: test: regression testing handling of out of bounds response codes
  Risk Level: n/a (test only)
  Testing: yes
  Docs Changes: no
  Release Notes: no
diff: @@ -157,6 +157,18 @@ TEST_P(ProtocolIntegrationTest, RouterRedirect) {
  response->headers().get(Http::Headers::get().Location)->value().getStringView());
  }
  +TEST_P(ProtocolIntegrationTest, UnknownResponsecode) {
  + initialize();
  +
  + codec_client_ = makeHttpConnection(lookupPort("http"));
  +
  + Http::TestResponseHeaderMapImpl response_headers{{":status", "600"}};
  + auto response = sendRequestAndWaitForResponse(default_request_headers_, 0, response_headers, 0);
  +
  + ASSERT_TRUE(response->complete());
  + EXPECT_EQ("600", response->headers().getStatusValue());
  +}
  +
  // Add a health check filter and verify correct computation of health based on upstream status.
  TEST_P(ProtocolIntegrationTest, ComputedHealthCheck) {
  config_helper_.addFilter(R"EOF(
  