#!/bin/sh

# Especially during feature development it can easily happen that a patch that

# was added to base branch as fix is added to derived branch as part of a

# feature by different developer under different name. Merging the base branch

# then becomes difficult.

# This script checks a few patch tags to match patch files across two

# kernel-source branches and moves patch files in the working tree to match

# filenames in the branch you specify.

# This then allows merging more easily: instead of duplicated patch files that

# git does not know how to detect you get conflicting added files under same

# filename which git does point out.

# Also if the reference branch contains duplicate files the rename is not

# stable. That is if you run renamefiles, commit the result, run it again, and

# there are changes again you have duplicate patches in the reference branch

# with which you are trying to aling patch names. This can be either false

# positive because mutiple patch tags are checked or an actual patch that

# applies indefinitely because it adds the same context it applies to which is

# applied multiple times.

if [ $# != 1 ] ; then

	echo Usage: $0 "<branch name>"

	echo Run in kernel-source to rename patches in the current branch to the same filename as they ahve in the given branch.

	exit 1

fi

branch=$1

trap 'rm -f "$temp"' EXIT

temp=$(mktemp)

git grep -iE '^(Git-commit:|No-fix:|\(cherry picked from commit)' $branch -- 'patches.*' | tr ':' ' ' | \

		awk '!/patches.kernel.org/ {fn=$2; hash=$NF; map[hash]=map[hash] fn;}

		      END				   { for (hash in map) printf("map[%s]=\"%s\"\n", hash, map[hash]); }' \

		>$temp

declare -A map

source $temp

grep -E "^[[:space:]]*patches\.[a-z]+/" < series.conf | while read patch ; do

	[ ! -f "$patch" ] && continue

	commit="$(awk -v IGNORECASE=1 '/^(Git-commit|No-fix):/ { print $2}

	/^\(cherry picked from commit/ { print $5}' $patch)"

	[ -z "$commit" ] && continue

	for fn in ${map[$commit]} ; do

		[ $fn != $patch ] && git mv $patch  $fn && sed -i -e "s,$patch,$fn," series.conf

	done

done