Call event_debug_unassign on internal events

I don't expect that many users will be so religious about calling
unassign, but we need to be so that it's at least possible to use
debug mode without eating memory.

bufferevent.c

@@ -539,10 +539,14 @@ _bufferevent_decref_and_unlock(struct bufferevent *bufev)
 			bufferevent_remove_from_rate_limit_group(bufev);
 		if (event_initialized(&bufev_private->rate_limiting->refill_bucket_event))
 			event_del(&bufev_private->rate_limiting->refill_bucket_event);
+		event_debug_unassign(&bufev_private->rate_limiting->refill_bucket_event);
 		mm_free(bufev_private->rate_limiting);
 		bufev_private->rate_limiting = NULL;
 	}
 
+	event_debug_unassign(&bufev->ev_read);
+	event_debug_unassign(&bufev->ev_write);
+
 	BEV_UNLOCK(bufev);
 	if (bufev_private->own_lock)
 		EVTHREAD_FREE_LOCK(bufev_private->lock,

evdns.c

@@ -2102,6 +2102,7 @@ server_port_free(struct evdns_server_port *port)
 		port->socket = -1;
 	}
 	(void) event_del(&port->event);
+	event_debug_unassign(&port->event);
 	EVTHREAD_FREE_LOCK(port->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
 	mm_free(port);
 }
@@ -2490,6 +2491,7 @@ _evdns_nameserver_add_impl(struct evdns_base *base, const struct sockaddr *addre
 out2:
 	CLOSE_SOCKET(ns->socket);
 out1:
+	event_debug_unassign(&ns->event);
 	mm_free(ns);
 	log(EVDNS_LOG_WARN, "Unable to add nameserver %s: error %d", debug_ntop(address), err);
 	return err;
@@ -3799,6 +3801,19 @@ evdns_err_to_string(int err)
     }
 }
 
+static void
+evdns_nameserver_free(struct nameserver *server)
+{
+	if (server->socket >= 0)
+	CLOSE_SOCKET(server->socket);
+	(void) event_del(&server->event);
+	event_debug_unassign(&server->event);
+	if (server->state == 0)
+		(void) event_del(&server->timeout_event);
+	event_debug_unassign(&server->timeout_event);
+	mm_free(server);
+}
+
 static void
 evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests)
 {
@@ -3826,12 +3841,7 @@ evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests)
 
 	for (server = base->server_head; server; server = server_next) {
 		server_next = server->next;
-		if (server->socket >= 0)
+		evdns_nameserver_free(server);
-			CLOSE_SOCKET(server->socket);
-		(void) event_del(&server->event);
-		if (server->state == 0)
-			(void) event_del(&server->timeout_event);
-		mm_free(server);
 		if (server_next == base->server_head)
 			break;
 	}

event.c

@@ -612,6 +612,7 @@ event_base_free(struct event_base *base)
 		EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
 		base->th_notify_fd[0] = -1;
 		base->th_notify_fd[1] = -1;
+		event_debug_unassign(&base->th_notify);
 	}
 
 	/* Delete all non-internal events. */
@@ -631,6 +632,7 @@ event_base_free(struct event_base *base)
 		struct common_timeout_list *ctl =
 		    base->common_timeout_queues[i];
 		event_del(&ctl->timeout_event); /* Internal; doesn't count */
+		event_debug_unassign(&ctl->timeout_event);
 		for (ev = TAILQ_FIRST(&ctl->events); ev; ) {
 			struct event *next = TAILQ_NEXT(ev,
 			    ev_timeout_pos.ev_next_with_common_timeout);
@@ -1397,6 +1399,7 @@ event_once_cb(evutil_socket_t fd, short events, void *arg)
 	struct event_once *eonce = arg;
 
 	(*eonce->cb)(fd, events, eonce->arg);
+	event_debug_unassign(&eonce->ev);
 	mm_free(eonce);
 }
 

http.c

@@ -953,8 +953,10 @@ evhttp_connection_free(struct evhttp_connection *evcon)
 		TAILQ_REMOVE(&http->connections, evcon, next);
 	}
 
-	if (event_initialized(&evcon->retry_ev))
+	if (event_initialized(&evcon->retry_ev)) {
 		event_del(&evcon->retry_ev);
+		event_debug_unassign(&evcon->retry_ev);
+	}
 
 	if (evcon->bufev != NULL)
 		bufferevent_free(evcon->bufev);
@@ -2555,6 +2557,7 @@ evhttp_del_accept_socket(struct evhttp *http, struct evhttp_bound_socket *bound)
 {
 	TAILQ_REMOVE(&http->sockets, bound, next);
 	event_del(&bound->bind_ev);
+	event_debug_unassign(&bound->bind_ev);
 	mm_free(bound);
 }
 

listener.c

@@ -216,6 +216,7 @@ event_listener_destroy(struct evconnlistener *lev)
 	event_del(&lev_e->listener);
 	if (lev->flags & LEV_OPT_CLOSE_ON_FREE)
 		EVUTIL_CLOSESOCKET(event_get_fd(&lev_e->listener));
+	event_debug_unassign(&lev_e->listener);
 }
 
 int

signal.c

@@ -318,6 +318,7 @@ evsig_dealloc(struct event_base *base)
 	int i = 0;
 	if (base->sig.ev_signal_added) {
 		event_del(&base->sig.ev_signal);
+		event_debug_unassign(&base->sig.ev_signal);
 		base->sig.ev_signal_added = 0;
 	}
 	for (i = 0; i < NSIG; ++i) {