Useful pre-commit hook for submodules

readme.md

Put pre-commit file into your submodule's hooks directory and make it executable.

In recent git versions submodule hooks directory will be located in $(parent-repo-path)/.git/modules/<relative path of your submodule>/hooks/.

pre-commit

#!/bin/sh

if git status | grep -i 'HEAD detached' > /dev/null 2>&1; then
    echo "You should not commit while in detached state, either create a new brach or checkout existing one before committing."
    exit 1
fi