tj.git-extras/bin/git-create-branch

#!/usr/bin/env bash

test $# -eq 0 && echo "branch argument required." 1>&2 && exit 1

# preference takes lowest priority; look for remote from prefs first
REMOTE_PREF=$(git config git-extras.create-branch.remote)
if [ -n "$REMOTE_PREF" ]; then
	REMOTE=$REMOTE_PREF
fi

while test $# != 0
do
	case $1 in
		-r|--remote)
			if [[ -n $2 ]]
			then
				REMOTE=$2
				shift
			else
				REMOTE=origin
			fi
			;;
		--from)
			if [[ -n $2 ]]; then
				START_POINT=$2
				shift
			fi
			;;
		*)
			BRANCH=$1
	esac
	shift
done

# handle ambiguous `-r` option argument by shift
if [[ -z $BRANCH ]] && [[ -n $REMOTE ]]
then
	BRANCH=$REMOTE
	REMOTE=origin
fi

test -z $BRANCH && echo "branch argument required." 1>&2 && exit 1

if [[ -n $REMOTE ]]
then
	stderr=$(git_extra_mktemp)
	git ls-remote --exit-code "$REMOTE" 1>/dev/null 2>"$stderr"
	REMOTE_EXIT=$?
	REMOTE_ERROR=$(<"$stderr")
	rm -f "$stderr"
	if [ $REMOTE_EXIT -eq 0 ]
	then
		if [[ -n $START_POINT ]]; then
			git fetch "$REMOTE"
			git checkout --track -b "$BRANCH" "$START_POINT"
			git push "$REMOTE" "HEAD:refs/heads/$BRANCH"
		else
			git push "$REMOTE" "HEAD:refs/heads/$BRANCH"
			git fetch "$REMOTE"
			git checkout --track -b "$BRANCH" "$REMOTE/$BRANCH"
		fi
		exit $?
	else
		echo
		echo "    Error connecting to remote '$REMOTE': $REMOTE_ERROR"
		echo
		exit $REMOTE_EXIT
	fi
fi

if [[ -n $START_POINT ]]
then
    git checkout -b "$BRANCH" "$START_POINT"
else
    git checkout -b "$BRANCH"
fi