#!/bin/sh

accept_rerere=t generate=no
while case "$#,$1" in 0,*) break;; *,-*) ;; esac
do
	case "$1" in
	-n)	accept_rerere= ;;
	*)	generate=yes
		break ;;
	esac
	shift
done

case "$generate" in
no)
	accept_rerere () {
		if test -z "$accept_rerere"
		then
			return 1
		fi
		if git diff |
		   grep -e "^.+" -e "^+." |
		   grep -e "^..<<<<<<<" -e "^..=======" -e "^..>>>>>>>" >/dev/null
		then
			return 1
		else
			EDITOR=: git commit -a --no-verify
			return 0
		fi
	}

	while read branch eh
	do
		case "$eh" in
		"")
			echo >&2 "* $branch"
			git merge "$branch" || accept_rerere || exit
			if git show-ref -q --verify "refs/merge-fix/$branch"
			then
				git cherry-pick --no-commit "refs/merge-fix/$branch" &&
				EDITOR=: git commit --amend -a
			fi
			;;
		pick" "*)
			echo >&2 "* $eh"
			git cherry-pick "$branch" || exit ;;
		*) echo >&2 "Eh? $branch $eh"; exit ;;
		esac
	done
	exit
esac

merge_msg="Merge branch '\(.*\)'"
x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
x40="$x40$x40$x40$x40$x40$x40$x40$x40"
LF='
'

show_merge () {
	branch=$(expr "$msg" : "$merge_msg") &&
	tip=$(git rev-parse --verify "refs/heads/$branch" 2>/dev/null) &&
	merged=$(git name-rev --refs="refs/heads/$branch" "$other" 2>/dev/null) &&
	merged=$(expr "$merged" : "$x40 \(.*\)") &&
	test "$merged" != undefined || {
		other=$(git log -1 --pretty='format:%s' $other) &&
		merged="$branch :rebased? $other"
	}
}

show_pick () {
	merged="$(git rev-parse --verify "$commit") pick $msg" 
}

echo '#!/bin/sh'
echo "$0 <<\\EOF"

git log --pretty=oneline --first-parent "$1" |
{
	series=
	while read commit msg
	do
		if other=$(git rev-parse -q --verify "$commit^2")
		then
			show_merge
		else
			show_pick
		fi

		if test -z "$series"
		then
			series="$merged"
		else
			series="$merged$LF$series"
		fi
	done
	echo "$series"
}

echo EOF