zfsbootmenu/install-helpers.sh: preserve relative symlinks

zfsbootmenu/install-helpers.sh

@@ -170,7 +170,42 @@ create_zbm_profiles() {
  ln -s "/root/.bashrc" "${BUILDROOT}/root/.profile"
 }
 
+zbm_install_symlink() {
+ [ -L "${1}" ] || return 1
+
+ # shellcheck disable=SC2154
+ case "${1}" in
+ "${zfsbootmenu_module_root}"/*) ;;
+ *) return 1 ;;
+ esac
+
+ local dest src
+
+ dest="$(readlink "${1}")" || dest=
+ [ -n "${dest}" ] || return 1
+
+ case "${dest}" in
+ /*) return 1 ;;
+ esac
+
+ src="${2:-"${1}"}"
+
+ # Attempt to install the target of the symlink
+ local rpath
+ if rpath="$(realpath -f "${1}")"; then
+ if [ -e "${rpath}" ] && [ ! -L "${rpath}" ]; then
+ zbm_install_file "${rpath}" "$(dirname "${src}")/${dest}" || return 1
+ fi
+ fi
+
+ ln -Ts "${dest}" "${BUILDROOT}/${src}" || return 1
+ return 0
+}
+
 zbm_install_file() {
+ # All symlinks in the ZBM module root should be relative
+ zbm_install_symlink "$@" && return 0
+
  case "${ZBM_BUILDSTYLE,,}" in
  mkinitcpio)
  if ! add_file "${1}" "${2}"; then
@@ -253,7 +288,7 @@ install_zbm_docs() {
 
 install_zbm_fonts() {
 
- [ -d "${zfsbootmenu_module_root}/fonts" ] || return 1 
+ [ -d "${zfsbootmenu_module_root}/fonts" ] || return 1
 
  # Install into a non-standard path so that the Dracut i18n module doesn't stomp over our custom fonts