reftable/merged: handle subiter cleanup on close only

When advancing one of the subiters fails we immediately release
resources associated with that subiter. This is not necessary though as
we will release these resources when closing the merged iterator anyway.

Drop the logic and only release resources when the merged iterator is
done. This is a mere cleanup that should help reduce the cognitive load
when reading through the code.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

reftable/merged.c

@@ -46,11 +46,8 @@ static int merged_iter_init(struct merged_iter *mi)
 				    &mi->subiters[i].rec);
 		if (err < 0)
 			return err;
-		if (err > 0) {
-			reftable_iterator_destroy(&mi->subiters[i].iter);
-			reftable_record_release(&mi->subiters[i].rec);
+		if (err > 0)
 			continue;
-		}
 
 		merged_iter_pqueue_add(&mi->pq, &e);
 	}
@@ -79,13 +76,8 @@ static int merged_iter_advance_subiter(struct merged_iter *mi, size_t idx)
 	int err;
 
 	err = iterator_next(&mi->subiters[idx].iter, &mi->subiters[idx].rec);
-	if (err < 0)
+	if (err)
 		return err;
-	if (err > 0) {
-		reftable_iterator_destroy(&mi->subiters[idx].iter);
-		reftable_record_release(&mi->subiters[idx].rec);
-		return 0;
-	}
 
 	merged_iter_pqueue_add(&mi->pq, &e);
 	return 0;