[exim] Possible minor Exim Bug

In redirect routers if the file is missing the router is skipped.
However if the parent directory of the file you are looking for is also
missing you get a defer for failing to stat the parent directory. Adding
a require_files line is a work around, but this should be fixed. Below
are two routers. The first works as expected. The second requires the
require_files lin.


virtualdomainfilter:
driver = redirect
allow_filter
check_ancestor
no_check_local_user
no_expn
file = /etc/vmail/filter.$domain
file_transport = address_file
pipe_transport = address_pipe
reply_transport = address_reply
skip_syntax_errors
user = mail
no_verify


# Virtual forwarding per domain

virtual_domain_filter:
driver = redirect
require_files = /etc/exim/control/domains/$domain/filter.txt
file = /etc/exim/control/domains/$domain/filter.txt
no_verify
no_expn
no_check_local_user
modemask = 0
check_ancestor
user = mail
skip_syntax_errors
allow_filter
allow_fail
forbid_pipe
forbid_filter_logwrite
forbid_filter_lookup
forbid_filter_readsocket
forbid_filter_readfile
forbid_filter_run
file_transport = address_file
pipe_transport = address_pipe
reply_transport = address_reply