Bourne-shell snippet for fixing up a git repo cloned from github to add the PR fetch set, for CLI diff of a PR.

fixup-repo

origin_url=$(git config --local --get remote.origin.url)
case $origin_url in
  github:*|git@github.*|*//github.*)
    fetches="$(git config --local --get-all remote.origin.fetch)"
    case $fetches in 
      *origin/pr/*) # no action
        ;;                      
      *)                
        git config --local --add remote.origin.fetch '+refs/pull/*/head:refs/remotes/origin/pr/*'
        ;;                      
    esac        
    ;;          
esac