kbuild: package: add -e and -u options to some shell scripts

Set -e to make these scripts fail on the first error.

Set -u because these scripts are invoked by Makefile, and do not work
properly without necessary variables defined.

I tweaked mkdebian to cope with optional environment variables.

Remove the explicit "test -n ..." from install-extmod-build.

Both options are described in POSIX. [1]

[1]: https://pubs.opengroup.org/onlinepubs/009604499/utilities/set.htmlSigned-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

scripts/package/builddeb

@@ -10,7 +10,7 @@
 # specified in KDEB_HOOKDIR) that will be called on package install and
 # removal.
 
-set -e
+set -eu
 
 is_enabled() {
 	grep -q "^$1=y" include/config/auto.conf

scripts/package/buildtar

@@ -11,7 +11,7 @@
 # Wichert Akkerman <wichert@wiggy.net>.
 #
 
-set -e
+set -eu
 
 #
 # Some variables and settings used throughout the script

scripts/package/gen-diff-patch

 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0-only
 
+set -eu
+
 diff_patch=$1
 
 mkdir -p "$(dirname "${diff_patch}")"

scripts/package/install-extmod-build

 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0-only
 
-set -e
+set -eu
 
 destdir=${1}
 
-test -n "${srctree}"
-test -n "${SRCARCH}"
-
 is_enabled() {
 	grep -q "^$1=y" include/config/auto.conf
 }

scripts/package/mkdebian

@@ -4,7 +4,7 @@
 #
 # Simple script to generate a debian/ directory for a Linux kernel.
 
-set -e
+set -eu
 
 is_enabled() {
 	grep -q "^$1=y" include/config/auto.conf
@@ -19,7 +19,7 @@ if_enabled_echo() {
 }
 
 set_debarch() {
-	if [ -n "$KBUILD_DEBARCH" ] ; then
+	if [ "${KBUILD_DEBARCH:+set}" ]; then
 		debarch="$KBUILD_DEBARCH"
 		return
 	fi
@@ -135,13 +135,21 @@ else
 fi
 maintainer="${name} <${email}>"
 
-if [ "$1" = --need-source ]; then
-	gen_source
-fi
+while [ $# -gt 0 ]; do
+	case "$1" in
+	--need-source)
+		gen_source
+		shift
+		;;
+	*)
+		break
+		;;
+	esac
+done
 
 # Some variables and settings used throughout the script
 version=$KERNELRELEASE
-if [ -n "$KDEB_PKGVERSION" ]; then
+if [ "${KDEB_PKGVERSION:+set}" ]; then
 	packageversion=$KDEB_PKGVERSION
 else
 	packageversion=$(${srctree}/scripts/setlocalversion --no-local ${srctree})-$($srctree/scripts/build-version)
@@ -158,7 +166,7 @@ debarch=
 set_debarch
 
 # Try to determine distribution
-if [ -n "$KDEB_CHANGELOG_DIST" ]; then
+if [ "${KDEB_CHANGELOG_DIST:+set}" ]; then
         distribution=$KDEB_CHANGELOG_DIST
 # In some cases lsb_release returns the codename as n/a, which breaks dpkg-parsechangelog
 elif distribution=$(lsb_release -cs 2>/dev/null) && [ -n "$distribution" ] && [ "$distribution" != "n/a" ]; then

scripts/package/mkspec

@@ -9,6 +9,8 @@
 #	Patched for non-x86 by Opencon (L) 2002 <opencon@rio.skydome.net>
 #
 
+set -eu
+
 output=$1
 
 mkdir -p "$(dirname "${output}")"