Script showing a bug in git: `stash save --untracked` makes an empty stash; it *looks* empty but it's not

bug_git_stash_untracked.sh

#!/bin/bash
# Test bug in git
# if you stash untracked files only
# then the stash looks empty by `stash show -p`
# but actually `stash apply` restores the empty files.
#

REPO_DIR=/tmp/test-git-stash-bug-$( date +%F_%H%M%S )


gs() {
  git status $@
}

pause_steps() {
  echo
  read -p "Type any key to continue to the next step"
  echo -e "\n\n"
  clear
}

step_header() {
  echo -e "\t\t\t"$@
  echo
}

define_first_step() {
  clear
  step_header $@
}

define_step() {
  pause_steps
  step_header $@
}





define_first_step "create new fresh git repo in $REPO_DIR"
git init $REPO_DIR
cd $REPO_DIR


define_step "create a couple of files/dirs and commit"
cat > file.txt <<-EOF
  osijfd oijgioasg
  dsgeigj et
  sdgtrh
EOF
mkdir src
cat > src/MyClass.java <<-EOF
  public class MyClass {

  
  }
EOF
git add file.txt src/
gs
git commit -m "initial"



define_step "edit src/MyClass.java and commit"
cat >> src/MyClass.java <<-EOF
  private class HiddenClass {
    public void foo(){}
  }
EOF
git add -u
gs
git commit -m "update MyClass"



define_step "create dir src/new-dir with one file inside"
mkdir src/new-dir
cat > src/new-dir/newfile-in-newdir.js <<-EOF
  ## aoijasiofjiofd
  #sdjfoisdjf

EOF



define_step "edit file.txt and stage it"
cat >> file.txt <<-EOF  

  [EDIT]
  dofjgih riuhg 
  oksjg eripoisdjg ';df;lpd
  '
EOF
git add file.txt
gs



define_step "stash"
git stash
gs



define_step "stash untracked"
git stash save -u "buggy-stash"
gs



define_step "stash list"
git stash list



define_step "stash show untracked, i.e. \`git stash show stash@{0} -p\`"
STASH_SHOW_OUT=$( git stash show stash@{0} -p )
if [[ -z "$STASH_SHOW_OUT" ]] ; then
  echo -e "\n\n\t\t>>>>>>>>>>>>>> BUG <<<<<<<<<<<<"
  echo -e "\t\tthe stash looks empty\n\n"
fi


define_step "apply stash with untracked files"
STASH_APPLY=$( git stash apply | grep 'ntracked files' | wc -l )
if [[ "$STASH_APPLY" -eq 0 ]] ; then
  echo -e "\n\n\t\t>>>>>>>>>>>>>> BUG <<<<<<<<<<<<"
  echo -e "\t\tuntracked files are lost!\n\n"
else
  echo -e "\n\n\t\t>>>>>>>>>>>>>> PASSED <<<<<<<<<<<<"
  echo -e "\t\tuntracked files are NOT lost!\n\n"
fi



echo
echo "For more inspection: $REPO_DIR"