check socket creation errors against PGINVALID_SOCKET

Bruce Momjian <bruce@momjian.us>

Commit: 41809346518a2b57530b22148609a346a718adc9
Author: Bruce Momjian <bruce@momjian.us>
Date: 2014-04-16T14:45:48Z
Releases: 9.4.0
check socket creation errors against PGINVALID_SOCKET

Previously, in some places, socket creation errors were checked for
negative values, which is not true for Windows because sockets are
unsigned.  This masked socket creation errors on Windows.

Backpatch through 9.0.  8.4 doesn't have the infrastructure to fix this.

Files