[Nix-dev] Can't understand how pull requests work

[Marco Maggesi]

I submitted this pull request last week

https://github.com/NixOS/nixpkgs/pull/216

I cannot understand how this request could be marked as merged and
closed by me (I don't have commit access on the nixpkgs project, i
think).

Also I noticed that no commit is associated to this pull request.
Can someone enlighten what actually happened?

Thansk,
M.