Git commit be9e60fc3c43cc49cc5d749924c3e96737ae297c  causes accepted
sockets to store 't as :host instead of the string-formatted peer IP
address.

This manifests as
 (process-contact proc)
returning something like
 (t 55269)

instead of the expected:
 ("192.168.2.13" 55269)

my clumsy attempt at a simple example:

(defun echo-server-filter (proc string) (print (format "%s %s"
(process-contact proc) string)))
(progn
  (setq echo-server-port 10000)
  (make-network-process :name "echo-server" :family 'ipv4 :service
echo-server-port :filter 'echo-server-filter :sentinel 'echo-server-filter
:server 't)
  (let ((client-process (open-network-stream "echo-client"
                             "*echo-client*" "localhost" echo-server-port)))
    (process-send-string client-process "hello world\n")
    (sleep-for 1)
    (delete-process client-process))
  (delete-process "echo-server")
  )