joyent/libuv — pull request #815 by wynnw (2013-05-29 14:28:59+00:00)
Title: Fix the usage of sendfile on OSX to respect the caller's length request.

- The osx version of sendfile takes the length from the &len pointer, so initialize it with the req->len
instead of just using 0. This was causing the sendfile call to always send to the end of the file,
making it impossible to send a middle section of a file.