MT#56465 Improve "this" side lookup by subs

During the monologues lookup in
`call_get_dialogue()`,

instead of relying on the very first available
other side subscription, when doing a lookup
of this side, try to look into all of them
to find available media with existing subs.

Change-Id: If232cd25f26a2bc56eb1f401ba5c2c8a13e3e463

daemon/call.c

@@ -4747,13 +4747,21 @@ static int call_get_dialogue(struct call_monologue *monologues[2], call_t *call,
 	 */
 	if (viabranch)
 		ft = t_hash_table_lookup(call->viabranches, viabranch);
-	/* top most subscription of tt */
+	/* first possible subscription of tt (other side) */
 	if (!ft) {
-		struct call_media *media = tt->medias->len ? tt->medias->pdata[0] : NULL;
-		if (media && media->media_subscriptions.head) {
+		/* find by any other's side subscriptions (expected one-monologue to one-monologue talk) */
+		for (int i = 0; i < tt->medias->len; i++)
+		{
+			struct call_media *media = tt->medias->pdata[i];
+			if (!media || !media->media_subscriptions.head)
+				continue;
 			struct media_subscription * ms = media->media_subscriptions.head->data;
-			if (ms->monologue)
+			if (ms->monologue) {
 				ft = ms->monologue;
+				__C_DBG("Found existing monologue '" STR_FORMAT "' for this side, by lookup of other side subscriptions",
+						STR_FMT(&ft->tag));
+				break;
+			}
 		}
 	}
 	/* otherwise create a brand-new one.