mg-update

#!/bin/sh

[ ! -n "${mg_home}" ] && . mg
need_mg_dir

git_current_branch() {
  git branch --no-color | grep '^\* ' | grep -v 'no branch' | sed 's/^* //g'
}

### Update child repositories

for child in $children; do
  # if child dir doesn't exist
  if [ ! -e $child ]; then
    url=`$git_config_cmd --get repo.$child.url`
    mg_exec_parent git clone $url $child

    # if child isn't a directory
  elif [ ! -d $child ]; then
    echo_fail "$child: exists and is not a directory, skipping!"

    # child must exist as directory
  else
    # if there's no .git dir
    if [ ! -d $child/.git ]; then
      echo_fail "$child: exists and isn't a git repository, skipping!"
    else
      mg_exec $child git fetch
      cd $child

      branch=`git_current_branch`
      remote=`git config branch.$branch.remote`
      remote_ref=`git config branch.$branch.merge`
      remote_branch=$remote/${remote_ref#refs/heads/}

      merge_base=`git merge-base $branch $remote_branch`

      local_dirty=( $(git status --porcelain -uall | awk '{ print $2 }' | sort) )
      local_diff=( $(git diff --name-only $merge_base $branch | sort) )
      remote_diff=( $(git diff --name-only $merge_base $remote_branch | sort) )

      conflicts=( $(printf "%s\\n" "${local_dirty[@]}" "${local_diff[@]}" "${remote_diff[@]}"  | sort | uniq -d) )

      cd $parent_dir

      if [ ! -z $conflicts ]; then
        echo_fail "Not auto-merging; the following files may cause conflicts: $conflicts"
        echo_fail "Please merge manually: $(fmt_cmd cd $child), $(fmt_cmd git commit) any recent changes, then $(fmt_cmd git merge $remote_branch)"
      else
        mg_exec $child git merge $remote_branch
      fi
    fi
  fi
done