evdns: fix EVDNS_BASE_DISABLE_WHEN_INACTIVE in case retransmit/retry

diff --git a/evdns.c b/evdns.c
index 6346b86be9623a1067cabb5490850c3da7514a55..5ec6a06008ee5f01a7f13fc185862817bc04d50f 100644 (file)
--- a/evdns.c
+++ b/evdns.c
@@ -541,6 +541,17 @@ nameserver_probe_failed(struct nameserver *const ns) {
        }
 }
 
+static void
+request_swap_ns(struct request *req, struct nameserver *ns) {
+       if (ns && req->ns != ns) {
+               EVUTIL_ASSERT(req->ns->requests_inflight > 0);
+               req->ns->requests_inflight--;
+               ns->requests_inflight++;
+
+               req->ns = ns;
+       }
+}
+
 /* called when a nameserver has been deemed to have failed. For example, too */
 /* many packets have timed out etc */
 static void
@@ -595,7 +606,7 @@ nameserver_failed(struct nameserver *const ns, const char *msg) {
                                if (req->tx_count == 0 && req->ns == ns) {
                                        /* still waiting to go out, can be moved */
                                        /* to another server */
-                                       req->ns = nameserver_pick(base);
+                                       request_swap_ns(req, nameserver_pick(base));
                                }
                                req = req->next;
                        } while (req != started_at);
@@ -708,7 +719,7 @@ request_reissue(struct request *req) {
        /* the last nameserver should have been marked as failing */
        /* by the caller of this function, therefore pick will try */
        /* not to return it */
-       req->ns = nameserver_pick(req->base);
+       request_swap_ns(req, nameserver_pick(req->base));
        if (req->ns == last_ns) {
                /* ... but pick did return it */
                /* not a lot of point in trying again with the */
@@ -2173,13 +2184,10 @@ evdns_request_timeout_callback(evutil_socket_t fd, short events, void *arg) {
                request_finished(req, &REQ_HEAD(req->base, req->trans_id), 1);
        } else {
                /* retransmit it */
-               struct nameserver *new_ns;
                log(EVDNS_LOG_DEBUG, "Retransmitting request %p; tx_count==%d",
                    arg, req->tx_count);
                (void) evtimer_del(&req->timeout_event);
-               new_ns = nameserver_pick(base);
-               if (new_ns)
-                       req->ns = new_ns;
+               request_swap_ns(req, nameserver_pick(base));
                evdns_request_transmit(req);
        }
        EVDNS_UNLOCK(base);