Don't create subproxies except when appropriate

src/stratifier.c

@@ -1283,9 +1283,9 @@ static void update_notify(ckpool_t *ckp, const char *cmd)
 	}
 	json_get_int(&id, val, "proxy");
 	json_get_int(&subid, val, "subproxy");
-	proxy = subproxy_by_id(sdata, id, subid);
-	if (unlikely(!proxy->subscribed)) {
-		LOGNOTICE("No valid proxy %d:%d subscription to update notify yet", id, subid);
+	proxy = existing_subproxy(sdata, id, subid);
+	if (unlikely(!proxy || !proxy->subscribed)) {
+		LOGINFO("No valid proxy %d:%d subscription to update notify yet", id, subid);
 		goto out;
 	}
 	if (!subid)
@@ -1397,7 +1397,11 @@ static void update_diff(ckpool_t *ckp, const char *cmd)
 		LOGNOTICE("Got updated diff for proxy %d", id);
 	else
 		LOGINFO("Got updated diff for proxy %d:%d", id, subid);
-	proxy = subproxy_by_id(sdata, id, subid);
+	proxy = existing_subproxy(sdata, id, subid);
+	if (!proxy) {
+		LOGINFO("No existing subproxy %d:%d to update diff", id, subid);
+		return;
+	}
 
 	/* We only really care about integer diffs so clamp the lower limit to
 	 * 1 or it will round down to zero. */
@@ -2043,7 +2047,9 @@ static void dead_proxy(sdata_t *sdata, const char *buf)
 	proxy_t *proxy;
 
 	sscanf(buf, "deadproxy=%d:%d", &id, &subid);
-	proxy = subproxy_by_id(sdata, id, subid);
+	proxy = existing_subproxy(sdata, id, subid);
+	if (!proxy)
+		return;
 	proxy->dead = true;
 	LOGNOTICE("Stratifier dropping clients from proxy %d:%d", id, subid);