Sadly, this does not work.

In the function, the remote (_ie_ origin) is already set, and the only argument should be a branch name. However, since this is a function, not an alias, Zsh completion is unable to see that the first argument to `git pull` is already there. As a result, using `git-pull` for completion will return a choice of remote names, instead of branch names.

I found using `git-checkout` is a good workaround, since it does complete branch names as first argument.

Again, if someone has a better solution, let me hear it. =D