libpq bug?

/*
 *  gcc -o pgsql_check pgsql_check.c -lpq
 *  ./pgsql_check
 *
 */


/*


valgrind:

==2490== Memcheck, a memory error detector
==2490== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==2490== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==2490== Command: ./pgsql_check
==2490==
==2490==
==2490== HEAP SUMMARY:
==2490==     in use at exit: 47,288 bytes in 2,864 blocks
==2490==   total heap usage: 5,670 allocs, 2,806 frees, 331,452 bytes allocated
==2490==
==2490== LEAK SUMMARY:
==2490==    definitely lost: 0 bytes in 0 blocks
==2490==    indirectly lost: 0 bytes in 0 blocks
==2490==      possibly lost: 0 bytes in 0 blocks
==2490==    still reachable: 47,288 bytes in 2,864 blocks
==2490==         suppressed: 0 bytes in 0 blocks
==2490== Rerun with --leak-check=full to see details of leaked memory
==2490==
==2490== For counts of detected and suppressed errors, rerun with: -v
==2490== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)


*/


#include <stdio.h>
#include <stdlib.h>

#include "/usr/include/postgresql/libpq-fe.h"


static void
exit_nicely(PGconn *conn)
{
    PQfinish(conn);
    exit(1);
}


int
main(int argc, char **argv)
{
    const char  *conninfo;
    PGconn      *conn;
    PGresult    *res;
    int         nFields,
                nRows;
    int         i,
                j;

    /*
     * If the user supplies a parameter on the command line, use it as the
     * conninfo string; otherwise default to setting dbname=postgres and using
     * environment variables or defaults for all other connection parameters.
     */
    if (argc > 1)
        conninfo = argv[1];
    else
        conninfo = "host=127.0.0.1 dbname=postgres user=postgres password=PASSWORD port=5432 connect_timeout=5";
    /* Make a connection to the database */
    conn = PQconnectdb(conninfo);

    /* Check to see that the backend connection was successfully made */
    if (PQstatus(conn) != CONNECTION_OK)
    {
        fprintf(stderr, "Connection to database failed: %s",
                PQerrorMessage(conn));
        exit_nicely(conn);
    }

    /* Start a transaction block */
    res = PQexec(conn, "BEGIN");
    PQclear(res);
    /* disable notice */
    res = PQexec(conn, "SET client_min_messages TO WARNING;");
    PQclear(res);
    /* end the transaction */
    res = PQexec(conn, "END");
    PQclear(res);


    /* close the connection to the database and clean-up */
    PQfinish(conn);

    return 0;
}