Improve PDPClients initialization (#5459)

* Refs #21433: Add Test

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

* Refs #21433: Avoid using multicast metatraffic for CLIENTS & SUPER_CLIENTS

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

* Refs #21433: Typo

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

---------

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>
(cherry picked from commit 451847c)

Author: cferreiragonz

src/cpp/rtps/builtin/discovery/participant/PDPClient.cpp

@@ -205,7 +205,7 @@ ParticipantProxyData* PDPClient::createParticipantProxyData(
     ParticipantProxyData* pdata = add_participant_proxy_data(participant_data.m_guid, is_server, &participant_data);
     if (pdata != nullptr)
     {
-        // Clients only assert its server lifeliness, other clients liveliness is provided
+        // Clients only assert its server liveliness, other clients liveliness is provided
         // through server's PDP discovery data
         if (is_server)
         {

src/cpp/rtps/participant/RTPSParticipantImpl.cpp

@@ -2850,9 +2850,13 @@ void RTPSParticipantImpl::get_default_metatraffic_locators(
 {
     uint32_t metatraffic_multicast_port = att.port.getMulticastPort(domain_id_);
 
-    m_network_Factory.getDefaultMetatrafficMulticastLocators(att.builtin.metatrafficMulticastLocatorList,
-            metatraffic_multicast_port);
-    m_network_Factory.NormalizeLocators(att.builtin.metatrafficMulticastLocatorList);
+    if (m_att.builtin.discovery_config.discoveryProtocol != DiscoveryProtocol::CLIENT &&
+            m_att.builtin.discovery_config.discoveryProtocol != DiscoveryProtocol::SUPER_CLIENT)
+    {
+        m_network_Factory.getDefaultMetatrafficMulticastLocators(att.builtin.metatrafficMulticastLocatorList,
+                metatraffic_multicast_port);
+        m_network_Factory.NormalizeLocators(att.builtin.metatrafficMulticastLocatorList);
+    }
 
     m_network_Factory.getDefaultMetatrafficUnicastLocators(att.builtin.metatrafficUnicastLocatorList,
             metatraffic_unicast_port_);

test/unittest/dds/participant/ParticipantTests.cpp

@@ -862,6 +862,28 @@ TEST(ParticipantTests, SimpleParticipantRemoteServerListConfiguration)
     EXPECT_EQ(ReturnCode_t::RETCODE_OK, DomainParticipantFactory::get_instance()->delete_participant(participant));
 }
 
+/**
+ * Test that checks a CLIENT participant is not initialized with builtin metatrafficMulticastLocators.
+ */
+TEST(ParticipantTests, NoBuiltinMetatrafficMulticastForClients)
+{
+    DomainParticipantQos qos;
+    qos.wire_protocol().builtin.discovery_config.discoveryProtocol = fastdds::rtps::DiscoveryProtocol::CLIENT;
+    DomainParticipant* participant = DomainParticipantFactory::get_instance()->create_participant(
+        (uint32_t)GET_PID() % 230, qos);
+    ASSERT_NE(nullptr, participant);
+
+    fastdds::rtps::RTPSParticipantAttributes attributes;
+    get_rtps_attributes(participant, attributes);
+    EXPECT_EQ(attributes.builtin.discovery_config.discoveryProtocol, fastdds::rtps::DiscoveryProtocol::CLIENT);
+    EXPECT_EQ(attributes.builtin.metatrafficMulticastLocatorList.size(), 0);
+
+    DomainParticipantQos result_qos = participant->get_qos();
+    EXPECT_EQ(RETCODE_OK, participant->set_qos(result_qos));
+
+    EXPECT_EQ(RETCODE_OK, DomainParticipantFactory::get_instance()->delete_participant(participant));
+}
+
 
 /**
  * Test that a SIMPLE participant is transformed into a CLIENT if the variable ROS_SUPER_CLIENT is false and into a SUPERCLIENT if it's true.