BUG #1771: re-connection to database error

The following bug has been logged online:

Bug reference:      1771
Logged by:          Mars
Email address:      mars_ytx@hotmail.com
PostgreSQL version: 7.4.1
Operating system:   5.8 Generic_117350-26 sun4u sparc SUNW,Ultra-5_10
Description:        re-connection to database error
Details:

I got one problem while trying to re-connect the postgres database in my
client program.
At first I started postgres database, and then started my program both on
linux and sparc.
Then I restart the postgres database. At this time, the process running on
linux could reconnect to database successfully. But on sparc, there is
error.
Below is the error information:
        could not connect to server: No such file or directory
        Is the server running on host 192.168.15.254 and accepting
        TCP/IP connections on port 5432?
But if I restart the my process, it connected to database again.

For the first connection, I use PQconnectdb(), the I use PQstatus() to check
the connection, if it is not CONNECTION_OK, i will call PQreset()