git 1.7.1 freezing during http transport with sideband

Hey guys,

Git 1.7.1 is freezing when I push something via http and the hook has
some output. From the client side, I see the hook output prefixed with
"remote: " as expected - and then the process just hangs.

The interesting part is I could work around it by adding a sleep to the hook.

Tested on debian 5.0.4 and git 1.7.1. Couldn't reproduce on a mac.

I started digging in the code to attempt to fix it but it will take me
a while heh, not proficient with C.