grubby-bls: lookup default entry by either id or title on grub2

There is a grub2-set-default script that can be used to set the default
entry. It can take an entry id, title or index as a parameter so grubby
should be able to also lookup a default entry using the title on grub2.

Related: rhbz#1654936

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

grubby-bls

@@ -125,25 +125,13 @@ get_default_index() {
 	index="$default"
     fi
 
-    # GRUB2 and zipl use different fields to set the default entry
-    if [[ $bootloader = "grub2" ]]; then
-	id="$default"
-    else
-	title="$default"
-    fi
-
     for i in ${!bls_file[@]}; do
         if [[ $i -eq $index ]]; then
             echo $i
             return
         fi
 
-        if [[ $bootloader = "grub2" && $id = ${bls_id[$i]} ]]; then
-            echo $i
-            return
-        fi
-
-        if [[ $bootloader = "zipl" && $title = ${bls_title[$i]} ]]; then
+        if [[ $default = ${bls_id[$i]} || $default = ${bls_title[$i]} ]]; then
             echo $i
             return
         fi

grubby.spec

@@ -1,6 +1,6 @@
 Name: grubby
 Version: 8.40
-Release: 22%{?dist}
+Release: 23%{?dist}
 Summary: Command line tool for updating bootloader configs
 License: GPLv2+
 URL: https://github.com/rhinstaller/grubby
@@ -130,6 +130,10 @@ current boot environment.
  %{_mandir}/man8/*.8*
 
 %changelog
+* Tue Dec 11 2018 Javier Martinez Canillas <javierm@redhat.com> - 8.40-23
+- grubby-bls: lookup default entry by either id or title on grub2
+  Related: rhbz#1654936
+
 * Fri Nov 30 2018 Javier Martinez Canillas <javierm@redhat.com> - 8.40-22
 - grubby-bls: also print the absolute path in the --default-kernel option
   Resolves: rhbz#1649778