git-merge-topics

#!/bin/bash

# © Copyright 2014-2023 by Geert Uytterhoeven
#
# This file is subject to the terms and conditions of the GNU General Public
# License.

set -e

STATEDIR=.git-merge-topics
FILE=$STATEDIR/topics
STATE=$STATEDIR/state

function usage()
{
        cat <<END

Usage: $(basename $0) [<topicfile>]

END
	exit -1
}

case $# in
0)
	if [ -d $STATEDIR -a -f $FILE ]; then
		read topicfile < $FILE
	else
		echo No merge in progress
		exit -1
	fi
	;;

1)
	case $1 in
	-h|--help)
		usage
		;;

	*)
		topicfile=$1
		;;
	esac
	;;

*)
	usage
	;;
esac

i=0
done=0
if [ -d $STATEDIR -a -f $FILE ]; then
	rm -f $FILE.tmp
	echo $topicfile > $FILE.tmp
	if ! cmp $FILE $FILE.tmp > /dev/null; then
		echo $(basename $0) $(cat $FILE) still in progress
		exit -1
	fi
	rm $FILE.tmp
	if [ -f $STATE ]; then
		done=$(cat $STATE)
	fi
else
	mkdir -p $STATEDIR
	echo $topicfile > $FILE
fi

# Merge various topic branches
sed -e 's/\s\s*#.*$//g' < $topicfile | grep -v '^#' | grep -v '^$' | \
while IFS= read line; do
	i=$((i + 1))
	if [ $done -lt $i ]; then
		cmd=${line%% *}
		args=${line#* }
		case $cmd in
		BREAK|BRK)
			echo
			echo Paused.  Remove BREAK to continue.
			exit -1
			;;

		merge)
			echo === Merging $args ===
			case $args in
			*\ *~*)
				remote=${args%~*}
				suffix=~${args#*~}
				git fetch -q $remote
				branch=FETCH_HEAD$suffix
				;;
			*\ *)
				git fetch -q $args
				branch=FETCH_HEAD
				;;

			*)
				branch=$args
				;;
			esac
			git show -s --oneline $branch
			git merge --no-ff --no-edit $branch
			;;

		pick)
			for commit in $args; do
				echo === Cherry-picking \"$(git show -s --pretty=%s $commit)\" ===
				git cherry-pick $commit
			done
			;;

		revert)
			for commit in $args; do
				echo === Reverting \"$(git show -s --pretty=%s $commit)\" ===
				git revert $commit
			done
			;;

		*)
			echo
			echo Unknown command $cmd
			exit -1
			;;
		esac

		echo $i > $STATE
	else 
		echo Skipping $line
	fi
done

rm -rf $STATEDIR