Thread: SIGSEGV in PQreset(..)

OS: FC4, 2.6.11-1.1369_FC4
PostgreSQL: postgresql-8.1.2-1PGDG (rpm install)
gcc: version 4.0.2 20051125 (Red Hat 4.0.2-8)

The following code raises SIGSEGV:

main.cpp (gcc -lstdc++ -lpq -g main.cpp)

extern "C"
{
    #include <libpq-fe.h>
}
int main(int arch, char* argv[])
{
        PGconn* conn = PQconnectdb("x");
        ConnStatusType status = PQstatus(conn);
    //status == CONNECTION_BAD
        PQreset(conn);
        return 0;
}

gdb:
Program received signal SIGSEGV, Segmentation fault.
0x0061371e in connectDBStart (conn=0x9f82008) at fe-connect.c:798

However, this code works ok:

main.cpp (gcc -lstdc++ -lpq -g main.cpp)

extern "C"
{
    #include <libpq-fe.h>
}
int main(int arch, char* argv[])
{
        PGconn* conn = PQconnectdb("user='x' password='x' dbname='x'");
        ConnStatusType status = PQstatus(conn);
    //status == CONNECTION_BAD
        PQreset(conn);
        status = PQstatus(conn);
    //status == CONNECTION_BAD
        return 0;
}

In both cases postmaster is not running.
The "successful" completion of second sample suggests me that SIGSEGV in the first sample is triggered by a bug.
Or is there any other return code indicating badly formated argument passed to PQconnectdb function?
I'm sorry if this is just a wrong usage of libpq API from my side.

Regards,
az

Arturs Zoldners <az@rpiva.lv> writes:
> The following code raises SIGSEGV:

>         PGconn* conn = PQconnectdb("x");
>         ConnStatusType status = PQstatus(conn);
>     //status == CONNECTION_BAD
>         PQreset(conn);

PQreset assumes it's been passed a reasonably valid PGconn, which is not
the case if conninfo_parse couldn't make any sense of the connect
options string.  We probably ought to add a state flag to indicate
whether the options have been set up successfully, and cause PQreset to
fail if not.  (The alternative seems to be for PQreset to refuse to do
anything if the connection state is CONNECTION_BAD, but that looks like
it would destroy most of the usefulness of PQreset ...)

            regards, tom lane