really treat the right side of acl.{allow,deny} as a list of users the current implementation seems to expect only user per pattern, which contradicts the documentation available at the file beginning.

#!/bin/sh

hg init
mkfifo p

hg serve --stdio < p &
P=$!
(echo lock; echo addchangegroup; sleep 5) > p &
Q=$!
sleep 3
kill -HUP $P
wait
ls .hg