joyent/libuv — pull request #817 by wynnw (2013-05-29 18:17:27+00:00)
Title:  darwin: fix sendfile call to respect the caller's length parameter

The darwin sendfile implementation uses the &len parameter as input
and output. The code was sending 0 (not using the value of
req->len) so the behavior wasn't what the caller was expecting.
This makes sure to initialize len with req->len to ensure that the
caller can send portions of a file (not always everything to the
end of the file).

(sorry for the churn - messed up the commit message format again)