git()
{
  if [[ $1 == "merge" ]] || [[ $1 == "rebase" ]] || [[ $1 == "pull" ]]; then
    command git "$@"
    rc=$?
    if [[ $rc == 1 ]]; then
      echo "There are conflicts, better run git-mergetool!!!"
      # There might be some other condition that returns a '1',
      # if so you can add another check like this:
      # if grep Conflicts $(git --git-dir)/MERGE_MSG;
      FILE="MERGETOOL"
      if [ -f $FILE ]; then
          command git mergetool
      fi
    fi
  else
    command git "$@"
  fi
}
ub