QSqlQuery::exec always return true for wrong queries (PostgreSql)

CREATE TEMPORARY TABLE test(field integer NOT NULL, CONSTRAINT pk PRIMARY KEY (field));
INSERT INTO test (field) values (1); -- OK
INSERT INTO test (field) values (1); -- NOK (PK violation)

bool QPSQLResult::reset (const QString& query)
{
...
==> we lost PQerrorMessage information for next results here:
while (PGresult *nextResultSet = d->drv_d_func()->getResult(d->stmtId))
            d->nextResultSets.append(nextResultSet);
...
}