#!/bin/sh
# Copyright (c) 2008, Nanako Shiraishi
# Prime rerere database from existing merge commits

setvar me = 'rerere-train'
setvar USAGE = ""$me rev-list-args""

setvar SUBDIRECTORY_OK = 'Yes'
setvar OPTIONS_SPEC = ''
source "$(git --exec-path)/git-sh-setup"
require_work_tree
cd_to_toplevel

# Remember original branch
setvar branch = $(git symbolic-ref -q HEAD) ||
setvar original_HEAD = $(git rev-parse --verify HEAD) || do {
	echo >&2 "Not on any branch and no commit yet?>&2 "Not on any branch and no commit yet?"
	exit 1
}

mkdir -p "$GIT_DIR/rr-cache" || exit

git rev-list --parents @ARGV |
while read commit parent1 other_parents
{
	if test -z $other_parents
	{
		# Skip non-merges
		continue
	}
	git checkout -q "$parent1^0"
	if git merge $other_parents >/dev/null 2>&1
	{
		# Cleanly merges
		continue
	}
	if test -s "$GIT_DIR/MERGE_RR"
	{
		git show -s --pretty=format:"Learning from %h %s" $commit
		git rerere
		git checkout -q $commit -- .
		git rerere
	}
	git reset -q --hard
}

if test -z $branch
{
	git checkout $original_HEAD
} else {
	git checkout ${branch#refs/heads/}
}