From 07e8552a3ec20b54ee5537ebaeb05217e4ed4d40 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
Date: Fri, 21 Feb 2014 00:30:34 +0100
Subject: [PATCH 3/3] Clone the repository into working directory.

This should fix most of the issues weird build systems have. Not all
possible -- e.g. they still can't know what branch is it -- but it's
a good step ahead.
---
 eclass/git-r3.eclass | 60 +++++++++++++++++++++-------------------------------
 1 file changed, 24 insertions(+), 36 deletions(-)

diff --git a/eclass/git-r3.eclass b/eclass/git-r3.eclass
index fb75cff..fd3610d 100644
--- a/eclass/git-r3.eclass
+++ b/eclass/git-r3.eclass
@@ -410,53 +410,46 @@ git-r3_checkout() {
 	local out_dir=${2:-${EGIT_CHECKOUT_DIR:-${WORKDIR}/${P}}}
 	local local_id=${3:-${CATEGORY}/${PN}/${SLOT%/*}}
 
-	local -x GIT_DIR GIT_WORK_TREE
+	local -x GIT_DIR
 	_git-r3_set_gitdir "${repos[0]}"
-	GIT_WORK_TREE=${out_dir}
-	mkdir -p "${GIT_WORK_TREE}" || die
 
 	einfo "Checking out ${repos[0]} to ${out_dir} ..."
 
-	if ! git cat-file -e refs/git-r3/"${local_id}"/__main__
-	then
+	if ! git cat-file -e refs/git-r3/"${local_id}"/__main__; then
 		if [[ ${EVCS_OFFLINE} ]]; then
 			die "No local clone of ${repos[0]}. Unable to work with EVCS_OFFLINE."
 		else
 			die "Logic error: no local clone of ${repos[0]}. git-r3_fetch not used?"
 		fi
 	fi
+	local new_commit_id=$(
+		git rev-parse --verify refs/git-r3/"${local_id}"/__main__
+	)
 
-	# Note: this is a hack to avoid parallel checkout issues.
-	# I will try to handle it without locks when I have more time.
-	local lockfile=${GIT_DIR}/.git-r3_checkout_lock
-	local lockfile_l=${lockfile}.${BASHPID}
-	touch "${lockfile_l}" || die
-	until ln "${lockfile_l}" "${lockfile}" &>/dev/null; do
-		sleep 1
-	done
-	rm "${lockfile_l}" || die
-
-	set -- git checkout -f refs/git-r3/"${local_id}"/__main__ .
+	set -- git clone --shared --no-checkout "${GIT_DIR}" "${out_dir}"/
 	echo "${@}" >&2
-	"${@}"
-	local ret=${?}
-
-	# Remove the lock!
-	rm "${lockfile}" || die
+	"${@}" || die "git clone (for checkout) failed"
 
-	[[ ${ret} == 0 ]] || die "git checkout refs/git-r3/${local_id}/__main__ failed"
+	git-r3_sub_checkout() {
+		local -x GIT_DIR=${out_dir}/.git
+		local -x GIT_WORK_TREE=${out_dir}
 
-	# diff against previous revision (if any)
-	local new_commit_id=$(git rev-parse --verify refs/git-r3/"${local_id}"/__main__)
-	local old_commit_id=$(
-		git rev-parse --verify refs/git-r3/"${local_id}"/__old__ 2>/dev/null
-	)
+		set -- git checkout --quiet "${new_commit_id}"
+		echo "${@}" >&2
+		"${@}" || die "git checkout ${new_commit_id} failed"
+	}
+	git-r3_sub_checkout
 
-	if [[ ! ${old_commit_id} ]]; then
+	if ! git cat-file -e refs/git-r3/"${local_id}"/__old__; then
 		echo "GIT NEW branch -->"
 		echo "   repository:               ${repos[0]}"
 		echo "   at the commit:            ${new_commit_id}"
 	else
+		# diff against previous revision
+		local old_commit_id=$(
+			git rev-parse --verify refs/git-r3/"${local_id}"/__old__ 2>/dev/null
+		)
+
 		echo "GIT update -->"
 		echo "   repository:               ${repos[0]}"
 		# write out message based on the revisions
@@ -473,10 +466,10 @@ git-r3_checkout() {
 	git update-ref refs/git-r3/"${local_id}"/{__old__,__main__} || die
 
 	# recursively checkout submodules
-	if [[ -f ${GIT_WORK_TREE}/.gitmodules ]]; then
+	if [[ -f ${out_dir}/.gitmodules ]]; then
 		local submodules
 		_git-r3_set_submodules \
-			"$(<"${GIT_WORK_TREE}"/.gitmodules)"
+			"$(<"${out_dir}"/.gitmodules)"
 
 		while [[ ${submodules[@]} ]]; do
 			local subname=${submodules[0]}
@@ -487,7 +480,7 @@ git-r3_checkout() {
 				url=${repos[0]%%/}/${url}
 			fi
 
-			git-r3_checkout "${url}" "${GIT_WORK_TREE}/${path}" \
+			git-r3_checkout "${url}" "${out_dir}/${path}" \
 				"${local_id}/${subname}"
 
 			submodules=( "${submodules[@]:3}" ) # shift
@@ -497,11 +490,6 @@ git-r3_checkout() {
 	# keep this *after* submodules
 	export EGIT_DIR=${GIT_DIR}
 	export EGIT_VERSION=${new_commit_id}
-
-	# create a fake '.git' directory to satisfy 'git rev-parse HEAD'
-	GIT_DIR=${GIT_WORK_TREE}/.git
-	git init || die
-	echo "${EGIT_VERSION}" > "${GIT_WORK_TREE}"/.git/HEAD || die
 }
 
 # @FUNCTION: git-r3_peek_remote_ref
-- 
1.9.0