[Exim] $local_part being set in apparent contradiction to th…

Hi all,

In the docs, in Chapter 11, about three quarters of the way down, it says:

$local_part: When an address is being routed, or delivered on its own, this
variable contains the local part. When a number of addresses are being
delivered together (for example, multiple RCPT commands in an SMTP session),
$local_part is not set.

I tried this out (with exim -bs) with 2 RCPT commands and the message got
delivered to both envelope recipients. It was a local delivery, and the
transport looks like this:

local_delivery:
  driver = appendfile
  file = ${lookup pgsql{select home_dir from local_users where \
    local_part = '$local_part'}{$value}fail}
  delivery_date_add
  envelope_to_add
  return_path_add

I'm confused, can anyone please help me out?

Cheers
Rich