Fix log deletion with no removal candidates

2 files changed, 10 insertions, 3 deletions

diff --git a/sql/sql.go b/sql/sql.go
index f33390d..eeafd90 100644
--- a/sql/sql.go
+++ b/sql/sql.go
@@ -186,11 +186,12 @@ func (c *Client) DeleteLogBefore(t time.Time) (err error) {
 	}
 	defer tx.Rollback()
 	var ids []int64
-	if err := tx.Select(&ids, "SELECT id FROM log WHERE time < $1", t.Unix()); err == sql.ErrNoRows {
-		return nil
-	} else if err != nil {
+	if err := tx.Select(&ids, "SELECT id FROM log WHERE time < $1", t.Unix()); err != nil {
 		return err
 	}
+	if len(ids) == 0 {
+		return nil
+	}
 	deleteByIds := []string{
 		"DELETE FROM log_rr_answer WHERE log_id IN (?)",
 		"DELETE FROM log WHERE id IN (?)",
diff --git a/sql/sql_test.go b/sql/sql_test.go
index 8c867ad..efa9ba7 100644
--- a/sql/sql_test.go
+++ b/sql/sql_test.go
@@ -152,6 +152,12 @@ func TestDeleteLogBefore(t *testing.T) {
 	if want, got := 0, count(t, c, "SELECT COUNT(*) FROM rr_answer WHERE name = $1", answer); got != want {
 		t.Errorf("got %d rows for answer %q, want %d", got, question, want)
 	}
+
+	// Delete logs in the far past which matches 0 entries.
+	oneYear := time.Hour * 8760
+	if err := c.DeleteLogBefore(u.Add(-oneYear)); err != nil {
+		t.Fatal(err)
+	}
 }
 
 func TestInterleavedRW(t *testing.T) {