makepkg: allow using GIT source URLs

Allow specifing GIT sources using the following syntax

source=('<folder>::<repo>#<fragment>')

This will download the git repo <repo> into <folder> (into $SRCDIR
if set, otherwise $startdir). <repo> must start with "git", but
non-git protocols are handled using (e.g.) "git+http://...".

The <fragment> can be used to specify a branch, tag, or commit to
build from. e.g. branch=maint.

Checksum entries for git sources should be "SKIP".

Signed-off-by: Allan McRae <allan@archlinux.org>

scripts/makepkg.sh.in

@@ -343,6 +343,88 @@ download_file() {
 	ln -s "$SRCDEST/$filename" "$srcdir/"
 }
 
+download_git() {
+	local netfile=$1
+
+	local fragment=${netfile##*#}
+	if [[ $fragment = "$netfile" ]]; then
+		unset fragment
+	fi
+
+	local dir=${netfile%%::*}
+	local repo=${netfile##*/}
+	repo=${repo%%#*}
+	repo=${repo%%.git*}
+
+	if [[ $dir = "$netfile" ]]; then
+		dir="${repo}"
+	fi
+
+	if [[ ! -d "$startdir"/$dir ]]; then
+		dir="$SRCDEST"/$dir
+	else
+		dir="$startdir"/$dir
+	fi
+
+	local url=$(get_url "$netfile")
+	url=${url##*git+}
+	url=${url%%#*}
+
+	if [[ ! -d "$dir" ]]; then
+		msg2 "$(gettext "Cloning %s %s repo...")" "${repo}" "git"
+		if ! git clone --mirror "$url" "$dir"; then
+			error "$(gettext "Failure while downloading %s %s repo")" "${repo}" "git"
+			plain "$(gettext "Aborting...")"
+			exit 1
+		fi
+	else
+		msg2 "$(gettext "Updating %s %s repo...")" "${repo}" "git"
+		cd_safe "$dir"
+		if ! git fetch --all -p; then
+			# only warn on failure to allow offline builds
+			warning "$(gettext "Failure while updating %s %s repo")" "${repo}" "git"
+		fi
+	fi
+
+	msg2 "$(gettext "Creating working copy of %s %s repo...")" "${repo}" "git"
+	pushd "$srcdir" &>/dev/null
+	rm -rf "${dir##*/}"
+
+	if ! git clone "$dir"; then
+		error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "git"
+		plain "$(gettext "Aborting...")"
+		exit 1
+	fi
+
+	cd_safe "${dir##*/}"
+
+	local ref
+	if [[ -n $fragment ]]; then
+		case ${fragment%%=*} in
+			commit|tag)
+				ref=${fragment##*=}
+				;;
+			branch)
+				ref=origin/${fragment##*=}
+				;;
+			*)
+				error "$(gettext "Unrecognized reference: %s")" "${fragment}"
+				plain "$(gettext "Aborting...")"
+				exit 1
+		esac
+	fi
+
+	if [[ -n $ref ]]; then
+		if ! git checkout -b makepkg $ref; then
+			error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "git"
+			plain "$(gettext "Aborting...")"
+			exit 1
+		fi
+	fi
+
+	popd &>/dev/null
+}
+
 download_sources() {
 	msg "$(gettext "Retrieving Sources...")"
 
@@ -359,6 +441,9 @@ download_sources() {
 			ftp|http|https|rsync|scp)
 				download_file "$netfile"
 				;;
+			git*)
+				download_git "$netfile"
+				;;
 			*)
 				error "$(gettext "Unknown download protocol: %s")" "$proto"
 				plain "$(gettext "Aborting...")"