resolved: use reference counting for DnsQueryCandidate objects

Follow-up for 4ea8b443de. The logic that manages DnsQueryCandidate is rather
complicated: a calls to dns_query_complete() that wants to destroy a
DnsQueryCandidate can be nested inside a deep chain of calls. Using reference
counts seems like the simplest approach.

DnsSearchDomain already uses reference counting.

This patch effectively brings dns_query_candidate_go() to the state before
4ea8b443de, but wraps the iteration over DnsQueryCandidate.transactions in
dns_query_candidate_ref+dns_query_candidate_unref.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 298ce21ae3..d77e81ae39 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -105,7 +105,7 @@ DnsScope* dns_scope_free(DnsScope *s) {
         dns_scope_abort_transactions(s);
 
         while (s->query_candidates)
-                dns_query_candidate_free(s->query_candidates);
+                dns_query_candidate_unref(s->query_candidates);
 
         hashmap_free(s->transactions_by_key);