resolved: make dns_transaction_gc return a pointer

_gc() does cleanup if it is possible. So far it returned a bool to
signal if it succeeded (false on success). When working on the resolved
code I had to look at the definition every time, because the (arguably
reversed) calling convention is unobvious. So let's return a pointer
(non-NULL: gc has not been done, NULL: gc has been done).

This fits nicely with the standard to return a pointer from all free
functions obviously.

2 files changed, 8 insertions, 8 deletions

diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index bd73aa5451..e1ff503929 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -141,23 +141,23 @@ DnsTransaction* dns_transaction_free(DnsTransaction *t) {
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free);
 
-bool dns_transaction_gc(DnsTransaction *t) {
+DnsTransaction* dns_transaction_gc(DnsTransaction *t) {
         assert(t);
 
+        /* Returns !NULL if we can't gc yet. */
+
         if (t->block_gc > 0)
-                return true;
+                return t;
 
         if (set_isempty(t->notify_query_candidates) &&
             set_isempty(t->notify_query_candidates_done) &&
             set_isempty(t->notify_zone_items) &&
             set_isempty(t->notify_zone_items_done) &&
             set_isempty(t->notify_transactions) &&
-            set_isempty(t->notify_transactions_done)) {
-                dns_transaction_free(t);
-                return false;
-        }
+            set_isempty(t->notify_transactions_done))
+                return dns_transaction_free(t);
 
-        return true;
+        return t;
 }
 
 static uint16_t pick_new_id(Manager *m) {
diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h
index 9376d504bf..3632daeb15 100644
--- a/src/resolve/resolved-dns-transaction.h
+++ b/src/resolve/resolved-dns-transaction.h
@@ -143,7 +143,7 @@ struct DnsTransaction {
 int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key, DnsPacket *bypass, uint64_t flags);
 DnsTransaction* dns_transaction_free(DnsTransaction *t);
 
-bool dns_transaction_gc(DnsTransaction *t);
+DnsTransaction* dns_transaction_gc(DnsTransaction *t);
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_gc);
 
 int dns_transaction_go(DnsTransaction *t);