Test what happens to a libpq connection when we close the file

README.md

A test to verify psycopg issue #263. Compile with:

$ gcc -I$(pg_config --includedir) -c testclose.c
$ gcc -o testclose testclose.o -L$(pg_config --libdir) -lpq

The output (with PostgreSQL 9.3.5) suggests PQstatus is not good to detect the closed fd.

$ ./testclose 
PQconsumeInput is fine
file closed
PQconsumeInput error: could not receive data from server: Bad file descriptor

PQstatus 0 CONNECTION_OK: 0
PQxnstatus 0 IDLE: 0

testclose.c

#include <stdio.h>
#include <unistd.h>
#include <libpq-fe.h>

int main(int argc, char **argv)
{
    PGconn *conn;
    char *conninfo = "";

    if (argc >= 2) {
        conninfo = argv[1];
    }

    conn = PQconnectdb(conninfo);
    if (PQstatus(conn) != CONNECTION_OK) {
        printf("bad connection: %s\n", PQerrorMessage(conn));
        return 1;
    }

    if (1 == PQconsumeInput(conn)) {
        printf("PQconsumeInput is fine\n");
    } else {
        printf("PQconsumeInput error: %s\n", PQerrorMessage(conn));
        return 1;
    }

    close(PQsocket(conn));
    printf("file closed\n");

    if (1 == PQconsumeInput(conn)) {
        printf("PQconsumeInput 2 is fine??\n");
    } else {
        printf("PQconsumeInput error: %s\n", PQerrorMessage(conn));
    }

    printf("PQstatus %d CONNECTION_OK: %d\n", PQstatus(conn), CONNECTION_OK);
    printf("PQxnstatus %d IDLE: %d\n", PQtransactionStatus(conn), PQTRANS_IDLE);

    return 0;
}