Fix: Remove generated .sfo file on clean #49

	name: Commit checker

	on:
	pull_request:

	jobs:
	commit-checker:
	name: Commit checker
	runs-on: ubuntu-latest

	steps:
	- name: Checkout
	uses: actions/checkout@v2
	with:
	fetch-depth: 4

	- name: Get pull-request commits
	run: \|
	set -x
	# actions/checkout did a merge checkout of the pull-request. As such, the first
	# commit is the merge commit. This means that on HEAD^ is the base branch, and
	# on HEAD^2 are the commits from the pull-request. We now check if those trees
	# have a common parent. If not, we fetch a few more commits till we do. In result,
	# the log between HEAD^ and HEAD^2 will be the commits in the pull-request.
	DEPTH=4
	while [ -z "$(git merge-base HEAD^ HEAD^2)" ]; do
	git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --deepen=${DEPTH} origin HEAD
	DEPTH=$(( ${DEPTH} * 4 ))
	done

	# Just to show which commits we are going to evaluate.
	git log --oneline HEAD^..HEAD^2

	- name: Checkout commit-checker
	uses: actions/checkout@v2
	with:
	repository: OpenTTD/OpenTTD-git-hooks
	path: git-hooks
	ref: master

	- name: Check commits
	run: \|
	set -x
	HOOKS_DIR=./git-hooks/hooks GIT_DIR=.git ./git-hooks/hooks/check-commits.sh HEAD^..HEAD^2
	echo "Commit checks passed"

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