Function pqPrepareAsyncResult

src/interfaces/libpq/fe-exec.c:838–862

* This subroutine prepares an async result object for return to the caller. * If there is not already an async result object, build an error object * using whatever is in conn->errorMessage. In any case, clear the async * result storage. */

 * result storage.
 */
PGresult *
pqPrepareAsyncResult(PGconn *conn)
{
	PGresult   *res;

	/*
	 * conn->result is the PGresult to return.  If it is NULL (which probably
	 * shouldn't happen) we assume there is an appropriate error message in
	 * conn->errorMessage.
	 */
	res = conn->result;
	if (!res)
		res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);

	/*
	 * Replace conn->result with next_result, if any.  In the normal case
	 * there isn't a next result and we're just dropping ownership of the
	 * current result.  In single-row mode this restores the situation to what
	 * it was before we created the current single-row result.
	 */
	conn->result = conn->next_result;
	conn->next_result = NULL;

	return res;
}

/*
 * pqInternalNotice - produce an internally-generated notice message