grubby-bls: strip only /boot from paths

If the /boot directory is a mount point, then the paths of the kernel and
initramfs images paths in the BLS snippet have to be relative to the root
of the boot partition. So the /boot prefix has to be stripped from paths
in this case.

But the function was wrongly stripping the entire path instead of only the
/boot prefix, which prevented having kernels and initrds in subdirectories.

Signed-off-by: Yuval Turgeman <yturgema@redhat.com>

grubby-bls

@@ -544,24 +544,28 @@ set_default_bls() {
 }
 
 remove_var_prefix() {
+    local prefix="$1"
+
+    [ -z "${prefix}" ] && return
+
     if [[ -n $remove_kernel && $remove_kernel =~ ^/ ]]; then
-       remove_kernel="/${remove_kernel##*/}"
+       remove_kernel="/${remove_kernel##${prefix}/}"
     fi
 
     if [[ -n $initrd ]]; then
-	initrd="/${initrd##*/}"
+	initrd="/${initrd##${prefix}/}"
     fi
 
     if [[ -n $extra_initrd ]]; then
-	extra_initrd=" /${extra_initrd##*/}"
+	extra_initrd=" /${extra_initrd##${prefix}/}"
     fi
 
     if [[ -n $kernel ]]; then
-	kernel="/${kernel##*/}"
+	kernel="/${kernel##${prefix}/}"
     fi
 
     if [[ -n $update_kernel && $update_kernel =~ ^/ ]]; then
-	update_kernel="/${update_kernel##*/}"
+	update_kernel="/${update_kernel##${prefix}/}"
     fi
 }
 
@@ -762,9 +766,7 @@ if [[ -n $display_info ]]; then
     display_info_values "${display_info}"
 fi
 
-if [[ $(get_prefix) == "/boot" ]]; then
-    remove_var_prefix
-fi
+remove_var_prefix "$(get_prefix)"
 
 if [[ -n $kernel ]]; then
     if [[ $copy_default = "true" ]]; then

grubby.spec

@@ -1,6 +1,6 @@
 Name: grubby
 Version: 8.40
-Release: 35%{?dist}
+Release: 36%{?dist}
 Summary: Command line tool for updating bootloader configs
 License: GPLv2+
 URL: https://github.com/rhinstaller/grubby
@@ -131,6 +131,9 @@ current boot environment.
  %{_mandir}/man8/*.8*
 
 %changelog
+* Tue Aug 06 2019 Yuval Turgeman <yturgema@redhat.com> - 8.40-36
+- grubby-bls: strip only /boot from paths
+
 * Thu Jul 25 2019 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-35
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild