Should libpq set close-on-exec flag on its socket?

It was suggested to me off-list that libpq should do
"fcntl(fd, F_SETFD, FD_CLOEXEC)" on the socket connecting to the server.
This would prevent any child program from accidentally or maliciously
interfering with the connection.  It would also prevent people from
deliberately turning over a connection to a child; I'm not sure that
that's useful, but I'm not sure it's useless either.

Comments, opinions?
        regards, tom lane