From 8e24a17d0d7f6ebe5fe7b9e242ce8e696ceeacbf Mon Sep 17 00:00:00 2001
From: Emanuele Torre <torreemanuele6@gmail.com>
Date: Sat, 20 Jun 2020 05:20:50 +0200
Subject: [PATCH] Meta: default SUDO_UID and SUDO_GID to 0 in build-image-*.sh
 scripts

In the GNU coreutils version of chown, ":" is a valid argument
(the command will result in a no-op), but POSIX chown does not
consider that valid.

If the user who ran build-image-*.sh was root, SUDO_UID and SUDO_GID
would not be set and, if the version of chown installed on the system
did not allow passing just a ":" as argument, the script would fail.

Let's default the value of SUDO_UID and SUDO_GID to 0 just in case.
---
 Meta/build-image-grub.sh | 2 ++
 Meta/build-image-qemu.sh | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/Meta/build-image-grub.sh b/Meta/build-image-grub.sh
index 6c1a428d24..fff4f64eb5 100755
--- a/Meta/build-image-grub.sh
+++ b/Meta/build-image-grub.sh
@@ -9,6 +9,8 @@ die() {
 
 if [ "$(id -u)" != 0 ]; then
     exec sudo -E -- "$0" "$@" || die "this script needs to run as root"
+else
+    : "${SUDO_UID:=0}" "${SUDO_GID:=0}"
 fi
 
 grub=$(command -v grub-install 2>/dev/null) || true
diff --git a/Meta/build-image-qemu.sh b/Meta/build-image-qemu.sh
index 578a56c4b1..86d6d271d6 100755
--- a/Meta/build-image-qemu.sh
+++ b/Meta/build-image-qemu.sh
@@ -9,6 +9,8 @@ die() {
 
 if [ "$(id -u)" != 0 ]; then
     exec sudo -E -- "$0" "$@" || die "this script needs to run as root"
+else
+    : "${SUDO_UID:=0}" "${SUDO_GID:=0}"
 fi
 
 if [ "$(uname -s)" = "Darwin" ]; then