yet another fix for tinode#738

server/hub.go

@@ -397,11 +397,11 @@ func (h *Hub) topicUnreg(sess *Session, topic string, msg *ClientComMessage, rea
 			// Case 1.1: topic is online
 			if (!asUid.IsZero() && t.owner == asUid) || (t.cat == types.TopicCatP2P && t.subsCount() < 2) {
 				// Case 1.1.1: requester is the owner or last sub in a p2p topic
-
 				t.markPaused(true)
 				hard := true
 				if msg != nil && msg.Del != nil {
-					hard = msg.Del.Hard
+					// Soft-deleting does not make sense for p2p topics.
+					hard = msg.Del.Hard || t.cat == types.TopicCatP2P
 				}
 				if err := store.Topics.Delete(topic, hard); err != nil {
 					t.markPaused(false)
@@ -446,6 +446,10 @@ func (h *Hub) topicUnreg(sess *Session, topic string, msg *ClientComMessage, rea
 			}
 
 			if len(subs) == 0 {
+				if tcat == types.TopicCatP2P {
+					// No subscribers: delete.
+					store.Topics.Delete(topic, true)
+				}
 				sess.queueOut(InfoNoActionReply(msg, now))
 				return nil
 			}

server/topic.go

@@ -2945,27 +2945,16 @@ func (t *Topic) replyDelMsg(sess *Session, asUid types.Uid, asChan bool, msg *Cl
 	return nil
 }
 
-// Shut down the topic in response to {del what="topic"} request
-// See detailed description at hub.topicUnreg()
-// 1. Checks if the requester is the owner. If so:
-// 1.2 Evict all sessions
-// 1.3 Ask hub to unregister self
-// 1.4 Exit the run() loop
-// 2. If requester is not the owner:
-// 2.1 If this is a p2p topic:
-// 2.1.1 Check if the other subscription still exists, if so, treat request as {leave unreg=true}
-// 2.1.2 If the other subscription does not exist, delete topic
-// 2.2 If this is not a p2p topic, treat it as {leave unreg=true}
+// Handle request to delete the topic {del what="topic"}.
+// 1. If requester is the owner then it should have been handled at the hub, log an error.
+// 2. If requester is not the owner, treat it like {leave unsub=true}.
 func (t *Topic) replyDelTopic(sess *Session, asUid types.Uid, msg *ClientComMessage) error {
 	if t.owner != asUid {
-		// Cases 2.1.1 and 2.2
-		if t.cat != types.TopicCatP2P || t.subsCount() == 2 {
-			return t.replyLeaveUnsub(sess, msg, asUid)
-		}
+		return t.replyLeaveUnsub(sess, msg, asUid)
 	}
 
-	// Notifications are sent from the topic loop.
-
+	// This is an indication of a bug.
+	logs.Err.Println("replyDelTopic called by owner (SHOULD NOT HAPPEN!)")
 	return nil
 }