From 0647e985fa05d09a7fecc801e9e23d6b513b7de4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rapha=C3=ABl=20Hertzog?= <raphael@offensive-security.com>
Date: Thu, 19 Dec 2019 16:21:58 +0100
Subject: [PATCH] chroot_live-packages: use dpkg-query to see if a package is
 installed

Closes: #944983
---
 functions/chroot.sh                | 11 +++++++++++
 scripts/build/chroot_live-packages |  4 ++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/functions/chroot.sh b/functions/chroot.sh
index 88c5466b8..0b54a3925 100755
--- a/functions/chroot.sh
+++ b/functions/chroot.sh
@@ -36,3 +36,14 @@ Chroot ()
 
 	return "${?}"
 }
+
+Chroot_has_package() {
+	PACKAGE="${1}"; shift
+	CHROOT="${2:-chroot}"; shift
+
+	if dpkg-query --admindir=${CHROOT}/var/lib/dpkg -s ${PACKAGE} >/dev/null 2>&1 | grep -q "^Status: install"
+	then
+		return 0
+	fi
+	return 1
+}
diff --git a/scripts/build/chroot_live-packages b/scripts/build/chroot_live-packages
index f3e52fc0f..a04e37667 100755
--- a/scripts/build/chroot_live-packages
+++ b/scripts/build/chroot_live-packages
@@ -53,7 +53,7 @@ case "${LB_INITSYSTEM}" in
 	systemd)
 		_PACKAGES="${_PACKAGES} systemd-sysv"
 
-		if [ -e chroot/var/lib/dpkg/info/sysvinit.list ]
+		if Chroot_has_package sysvinit
 		then
 			Chroot chroot "dpkg --force-remove-essential --purge sysvinit"
 		fi
@@ -62,7 +62,7 @@ case "${LB_INITSYSTEM}" in
 	sysvinit)
 		_PACKAGES="${_PACKAGES} sysvinit"
 
-		if [ -e chroot/var/lib/dpkg/info/systemd-sysv.list ]
+		if Chroot_has_package systemd-sysv
 		then
 			Chroot chroot "dpkg --force-remove-essential --purge systemd systemd-sysv"
 		fi