[mDNS] Only consider fully qualified discovery results (#5348)

* [mDNS] only consider fully qualified results

Signed-off-by: Andrew Fiddian-Green <software@whitebear.ch>

Author: andrewfg

bundles/org.openhab.core.config.discovery.mdns/src/main/java/org/openhab/core/config/discovery/mdns/internal/MDNSDiscoveryService.java

@@ -190,11 +190,16 @@ public Set<ThingTypeUID> getSupportedThingTypes() {
 
     @Override
     public void serviceAdded(@NonNullByDefault({}) ServiceEvent serviceEvent) {
-        considerService(serviceEvent);
+        /**
+         * Do nothing when a service is added, as we will get a <code>serviceResolved</code> event afterwards,
+         * which contains the fully resolved ServiceInfo. If we would already create a DiscoveryResult here,
+         * we would not have the necessary full information.
+         */
     }
 
     @Override
     public void serviceRemoved(@NonNullByDefault({}) ServiceEvent serviceEvent) {
+        // note: {@link ServiceEvent} JavaDoc says getInfo() result can be null; but seems never to be so here.
         for (MDNSDiscoveryParticipant participant : participants) {
             if (participant.getServiceType().equals(serviceEvent.getType())) {
                 removeDiscoveryResult(participant, serviceEvent.getInfo());
@@ -204,6 +209,7 @@ public void serviceRemoved(@NonNullByDefault({}) ServiceEvent serviceEvent) {
 
     @Override
     public void serviceResolved(@NonNullByDefault({}) ServiceEvent serviceEvent) {
+        // note: {@link ServiceEvent} JavaDoc says getInfo() result can be null; but seems never to be so here.
         considerService(serviceEvent);
     }
 

itests/org.openhab.core.config.discovery.mdns.tests/src/main/java/org/openhab/core/config/discovery/mdns/internal/MDNSDiscoveryServiceOSGiTest.java

@@ -81,11 +81,11 @@ public void testThingDiscoveredAndRemoved() {
         mdnsDiscoveryService.addDiscoveryListener(mockDiscoveryListener);
 
         mdnsDiscoveryService.serviceAdded(mockServiceEvent);
-        verify(mockDiscoveryListener, timeout(2000).times(1)).thingDiscovered(mdnsDiscoveryService, discoveryResult);
+        verify(mockDiscoveryListener, timeout(2000).times(0)).thingDiscovered(mdnsDiscoveryService, discoveryResult);
         verifyNoMoreInteractions(mockDiscoveryListener);
 
         mdnsDiscoveryService.serviceResolved(mockServiceEvent);
-        verify(mockDiscoveryListener, timeout(2000).times(2)).thingDiscovered(mdnsDiscoveryService, discoveryResult);
+        verify(mockDiscoveryListener, timeout(2000).times(1)).thingDiscovered(mdnsDiscoveryService, discoveryResult);
         verifyNoMoreInteractions(mockDiscoveryListener);
 
         mdnsDiscoveryService.serviceRemoved(mockServiceEvent);