Backport fix to GRUB_DISABLE_SUBMENU value parsing

Fixes QubesOS/qubes-issues#4801

0021-Fix-bad-test-on-GRUB_DISABLE_SUBMENU.patch

@@ -0,0 +1,38 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Prarit Bhargava <[email protected]>
+Date: Wed, 12 Mar 2014 10:58:16 -0400
+Subject: [PATCH] Fix bad test on GRUB_DISABLE_SUBMENU.
+
+The file /etc/grub.d/10_linux does
+
+if [ "x$is_top_level" = xtrue ] && [ "x${GRUB_DISABLE_SUBMENU}" != xy ]; then
+
+when it should do
+
+if [ "x$is_top_level" = xtrue ] && [ "x${GRUB_DISABLE_SUBMENU}" != xtrue ]; then
+
+which results in submenus in /boot/grub2/grub.cfg when
+GRUB_DISABLE_SUBMENU="yes".
+
+Resolves: rhbz#1063414
+---
+ util/grub.d/10_linux.in | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
+index 61ebd7dc714..87a7da34982 100644
+--- a/util/grub.d/10_linux.in
++++ b/util/grub.d/10_linux.in
+@@ -261,7 +261,11 @@ while [ "x$list" != "x" ] ; do
+     fi
+   fi
+
+-  if [ "x$is_top_level" = xtrue ] && [ "x${GRUB_DISABLE_SUBMENU}" != xy ]; then
++  if [ "x${GRUB_DISABLE_SUBMENU}" = "xyes" ] || [ "x${GRUB_DISABLE_SUBMENU}" = "xy" ]; then
++    GRUB_DISABLE_SUBMENU="true"
++  fi
++
++  if [ "x$is_top_level" = xtrue ] && [ "x${GRUB_DISABLE_SUBMENU}" != xtrue ]; then
+     linux_entry "${OS}" "${version}" simple \
+     "${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_LINUX_DEFAULT}"
+

grub2.spec

@@ -588,6 +588,7 @@ Source13:	99-grub-mkconfig.install
 Patch0000: 0000-compiler-unused.patch
 Patch0007: 0007-re-write-.gitignore.patch
 Patch0012: 0012-Move-bash-completion-script-922997.patch
+Patch0021: 0021-Fix-bad-test-on-GRUB_DISABLE_SUBMENU.patch
 Patch0041: 0041-Don-t-say-GNU-Linux-in-generated-menus.patch
 Patch0044: 0044-Add-.eh_frame-to-list-of-relocations-stripped.patch
 Patch0048: 0048-Replace-a-lot-of-man-pages-with-slightly-nicer-ones.patch