Regression introduced in trunk r13201 (large rock merge)

Hi,
  it appears that the large rock merge has introduced a regression,
probably related to the handling of keepalive and/or about finishing
to send an object to a client.

I have confirmed that the issue is NOT present in revno 13200, but it
is present in r13203 (r13201 and r13202 do not compile).
To reproduce, it is enough to use ab on squid, NOT enabling keepalive
(with keepalive enabled, squid works just fine).

$ ab -c10 -n100 -X localhost:3128 http://www.example.com/

Notice: it doesn't make a difference whether a rock cache_dir is used
or whether collapsed_forwarding is enabled or not; the issue is
present regardless.

-- 
    Kinkie