git-mm.sh

#!/usr/bin/env bash

# Do an octopus merge and select a strategy for each branch you
# want to merge.

STRATEGY="recursive"
HEADS=( $(git rev-parse HEAD) )
git checkout HEAD^{}

while [ $# -gt 0 ]; do
    if [ "$1" = "-s" ]; then
	shift; STRATEGY="$1"
    else
	printf "Merging $1 with $STRATEGY strategy... "
	HEADS[${#HEADS[*]}]=$(git rev-parse $1)
	if ! git merge -s $STRATEGY $1 1>/dev/null 2>&1; then
	    printf "failed\n"; exit 1
	fi
	printf "\n"
    fi

    shift
done

n=$(( ${#HEADS[*]} - 1 ))
git reset --soft HEAD~$n

rm -f .git/MERGE_HEAD
for head in ${HEADS[@]}; do
    echo $head >> .git/MERGE_HEAD
done

git commit