unit test the nil case of Hasresultset

Author: stgarrity

mysql/result_test.go

@@ -17,3 +17,10 @@ func TestHasResultset_true(t *testing.T) {
 	b := r.HasResultset()
 	require.Equal(t, true, b)
 }
+
+// this shouldn't happen after d02e79a, but test just in case
+func TestHasResultset_nil(t *testing.T) {
+	var r *Result
+	b := r.HasResultset()
+	require.Equal(t, false, b)
+}