Found by Address Sanitizer.
dataset_set_session (ds, NULL);
dataset_clear (ds);
dict_unref (ds->dict);
dataset_set_session (ds, NULL);
dataset_clear (ds);
dict_unref (ds->dict);
+ dict_unref (ds->permanent_dict);
caseinit_destroy (ds->caseinit);
trns_chain_destroy (ds->permanent_trns_chain);
dataset_transformations_changed__ (ds, false);
caseinit_destroy (ds->caseinit);
trns_chain_destroy (ds->permanent_trns_chain);
dataset_transformations_changed__ (ds, false);