#!/bin/sh
#
# When updating a branch, ensure it has the latest changes
# from other branches, e.g. stable.
#
# While this forces merging sooner than devs may like, it
# assures deployment and qa staff that the latest revisions
# they are qa'ing will always have the last stable release
# in it.
#

# Command line
refname="$1"
oldrev="$2"
newrev="$3"

# Look up the config variable and exit if not set
follows=$(git config hooks.ensure-follows)
if [[ $? -ne 0 ]] ; then
	exit 0
fi

# Branch deletions are okay
if expr "$newrev" : '0*$' >/dev/null ; then
	exit 0
fi

# We only care about branches moving--ignore tags.
case "$refname" in
	refs/heads/*)
		short_refname=${refname##refs/heads/}
		;;
	*)
		exit 0
		;;
esac

follows=($follows)
count=${#follows[@]}
for ((i = 0 ; i < count ; i++)) do
	follow="${follows[$i]}"
	missing_commits=$(git log ^$newrev $follow --pretty=oneline | wc -l)
	if [ $missing_commits -ne 0 ] ; then
		echo "----------------------------------------------------"
		echo
		echo "You need to merge $follow into $short_refname"
		echo
		echo "----------------------------------------------------"
		exit 1
	fi
done

exit 0