Custom git command autocompletion

Question

I have implemented a custom git command by writing a shell script located in /usr/local/bin. It works fine, but I would like the script to autocomplete branches in the command line, just like git checkout [TAB][TAB]. How could this be done?

EDIT: Just adding some context: git allows you to very easily add your own commands by creating a script git-$subcommandName. In my case here git-install, the script facilitates checking out a branch, building, packaging, and installing the source code.

Answer 1

Figured it out. I needed to download git bash completion (here), create a new file in /etc/bash_completion.d with the following contents:

source ~/.git-completion.bash
_git_install ()
{
  __gitcomp_nl "$(__git_refs)"
}

and then exec bash to reload completion scripts.