dig +nssearch: send more queries even if sending the previous one fails

In the NSSEARCH followup lookup, when one of the queries fails to be
sent, DiG doesn't start the next query. This is a mistake, because in
NSSEARCH mode the queries are independent and DiG shouldn't stop the
lookup process just because sending a query to one of the name servers
returns an error code.

Restructure the `send_done()` function to unconditionally send the next
query in NSSEARCH mode, if it exists.

(cherry picked from commit 49ac879dfad91ac08201be3e351450fd9d83b9f5)

diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index b1b2b605e6109104ab15b452a5c06bca11ca701d..6a3eec31f0c9bbb6d56036d27ab3f3b88453cef1 100644 (file)
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -2673,7 +2673,6 @@ setup_lookup(dig_lookup_t *lookup) {
 static void
 send_done(isc_nmhandle_t *handle, isc_result_t eresult, void *arg) {
        dig_query_t *query = (dig_query_t *)arg;
-       dig_query_t *next = NULL;
        dig_lookup_t *l = NULL;
 
        REQUIRE(DIG_VALID_QUERY(query));
@@ -2704,39 +2703,31 @@ send_done(isc_nmhandle_t *handle, isc_result_t eresult, void *arg) {
                return;
        } else if (eresult != ISC_R_SUCCESS) {
                debug("send failed: %s", isc_result_totext(eresult));
-               query_detach(&query);
-               lookup_detach(&l);
-               UNLOCK_LOOKUP;
-               return;
        }
 
        if (l->ns_search_only && !l->trace_root) {
+               dig_query_t *next = ISC_LIST_NEXT(query, link);
                bool tcp_mode = l->tcp_mode;
 
-               debug("sending next, since searching");
-               next = ISC_LIST_NEXT(query, link);
-
                query_detach(&query);
                lookup_detach(&l);
 
                if (next == NULL) {
                        clear_current_lookup();
                } else {
+                       debug("sending next, since searching");
+
                        if (tcp_mode) {
                                start_tcp(next);
                        } else {
                                start_udp(next);
                        }
                }
-
-               check_if_done();
-               UNLOCK_LOOKUP;
-               return;
+       } else {
+               query_detach(&query);
+               lookup_detach(&l);
        }
 
-       query_detach(&query);
-       lookup_detach(&l);
-
        check_if_done();
        UNLOCK_LOOKUP;
 }