Add the current branch name to the beginning of commit messages

prepare-commit-msg

#!/bin/sh

branch_name=$(git symbolic-ref -q HEAD)
branch_name=${branch_name##refs/heads/}
branch_name=${branch_name:-HEAD}

firstLine=$(head -n1 $1)

if [ -z "$firstLine"  ] ;then #Check that this is not an amend by checking that the first line is empty
    sed -i "1s@^@$branch_name: \n@" $1 #Insert branch name at the start of the commit message file
fi