addon_*_bsd.cfg: don't try to modify if file doesn't exist

This exhibits an ugly error message if no such file exists,
so let's check if any such file exists before trying to
operate on them

diff --git a/templates/grub-pxelinux_config b/templates/grub-pxelinux_config
index 50fc1bd..8360ac3 100644 (file)
--- a/templates/grub-pxelinux_config
+++ b/templates/grub-pxelinux_config
@@ -107,7 +107,9 @@ if [ -d "$MOUNT_POINT_"/boot/release ] ; then
 fi
 
 # adjust ldbsd.com bootline
-sed -i -e 's#\(.*kernel .*/ldbsd.com\)#\1 set image /boot/addons/bsd4grml/bsd.rd`echo Type "boot" to load MirOS bsd4grml via keeppxe#' "$TFTPD_DATA_DIR_/"addon_*_bsd.cfg
+if ls "$TFTPD_DATA_DIR_/"addon_*_bsd.cfg >/dev/null 2>&1; then
+  sed -i -e 's#\(.*kernel .*/ldbsd.com\)#\1 set image /boot/addons/bsd4grml/bsd.rd`echo Type "boot" to load MirOS bsd4grml via keeppxe#' "$TFTPD_DATA_DIR_/"addon_*_bsd.cfg
+fi
 
 # remove grub entries
 rm -f "$TFTPD_DATA_DIR_/"addon_*grub*.cfg