website-build: avoid unnecessary git fetch

When we already have the right untitled revision checked out, we don't
need to try to fetch its revision again. This also enable offline
builds in that case.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
Acked-by: Adrien 'neox' Bourmault <neox@gnu.org>

website-build/build.sh

@@ -51,12 +51,17 @@ sync_repo()
 			git -C "${dst_path}" checkout "${src_revision}"
 		fi
 	elif [ -z "${src_path}" ] ; then
+		localrev="$(git --no-pager log --oneline HEAD -1 --format='%H')"
+
 		git -C "${dst_path}" remote get-url origin || \
 		    git -C "${dst_path}" remote add origin "${src_uri}"
 		git -C "${dst_path}" remote set-url origin "${src_uri}"
 		git -C "${dst_path}" clean -dfx
+
+		if [ "${localrev}" != "${src_revision}" ] ; then
 			git -C "${dst_path}" fetch origin
 			git -C "${dst_path}" checkout "${src_revision}"
+		fi
 
 	else
 		rm -rf "${dst_path}"