Don't let the kernel parameters override the subvol for the snapshot (#85)

Previously, the kernel parameters came after the `rootflags=subvol=<snapshot>`
argument. This means that when the user's standard kernel parameters also
contain a `rootflags=subvol=<root>`, it will override the subvol flag of the
snapshot. So put the snapshot's subvol flag last.

41_snapshots-btrfs

@@ -152,6 +152,7 @@ test_btrfs()
 	fi
 	set -e
 }
+
 ##############
 ### Script ###
 ##############
@@ -207,7 +208,7 @@ make_menu_entries()
 		fi
 		echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
 		echo 'Loading Kernel: "${k}" ...'
-		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
+		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw ${kernel_parameters} rootflags=subvol=\""${snap_dir_name}"\""
 				if [[ -f "${boot_dir}"/"${u}" && "${i}" != "${prefix_i}-${kversion}-${alt_suffix_i}" ]] ; then
 					entry "\
 		echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
@@ -238,12 +239,17 @@ snapshot_list()
 {
 	# Query info from snapper if it is installed
 	type snapper >/dev/null 2>&1
-	if [[ $? -eq 0 ]]; then
-		local snapper_ids=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 1))
-		local snapper_types=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 2))
+	if [ $? -eq 0 ]; then
+		if [ -s "/etc/snapper/configs/$snapper_config" ]; then
+			printf "# Info: snapper detected, using config '$snapper_config'\n" >&2
+			local snapper_ids=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 1))
+			local snapper_types=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 2))
 
-		IFS=$'\n'
-		local snapper_descriptions=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | rev | cut -d'|' -f 2 | rev))
+			IFS=$'\n'
+			local snapper_descriptions=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | rev | cut -d'|' -f 2 | rev))
+		else
+			printf "# Warning: snapper detected but config '$snapper_config' does not exist\n" >&2
+		fi
 	fi
 
 	IFS=$'\n'
@@ -523,11 +529,11 @@ check_uuid_required
 if [[ "$override_boot_partition_detection" == "true" ]]; then
 	printf "# Info: Override boot partition detection : enable \n" >&2 ;
 	boot_separate
-	else
+else
 	if [[ "$root_uuid" != "$boot_uuid" ]]; then
 		printf "# Info: Separate boot partition detected \n" >&2 ;
 		boot_separate
-		else
+	else
 		printf "# Info: Separate boot partition not detected \n" >&2 ;
 		boot_bounded
 	fi

README.md

@@ -132,10 +132,10 @@ You have the possibility to modify many parameters in `/etc/default/grub-btrfs/c
 	
 ##
 ### Automatically update grub
-If you would like Grub to automatically update when a snapshots is made or deleted:
+If you would like Grub to automatically update when a snapshot is made or deleted:
 * Mount your subvolume which contains snapshots to `/.snapshots`
 * Use `systemctl start/enable grub-btrfs.path`
-* `grub-btrfs.path` automatically (re)generate `grub.cfg` when a modification appear in `/.snapshots`
+* `grub-btrfs.path` automatically (re)generates `grub.cfg` when a modification appears in `/.snapshots`
 ##
 ### Special thanks for assistance and contributions
 * [maximbaz](https://github.com/maximbaz)