Merge commit 'dkg/master'

1 files changed, 24 insertions, 3 deletions

diff --git a/packaging/debian/monkeysphere.prerm b/packaging/debian/monkeysphere.prerm
index 5835f53..1a5135a 100755
--- a/packaging/debian/monkeysphere.prerm
+++ b/packaging/debian/monkeysphere.prerm
@@ -2,10 +2,31 @@
 
 # prerm script for monkeysphere
 
-# Author: Jameson Rollins <jrollins@finestructure.net>
-# Copyright 2008-2009
+# the only thing we're doing here is making sure that the local
+# administrator is not trying to downgrade to a version below 0.23,
+# since there was such a major reorganization of system data during
+# the transition to 0.23.
 
-true
+# Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+# Copyright 2009
+
+set -e
+
+case "$1" in
+    upgrade)
+	if dpkg --compare-versions "$2" lt 0.23 ; then
+	    cat >&2 <<EOF
+
+Downgrading the monkeysphere to a version earlier than 0.23 can have
+BAD CONSEQUENCES, including potentially locking you out of the system.
+Downgrading in this fashion is NOT SUPPORTED.
+
+EOF
+
+	    exit 1
+	fi
+    ;;
+esac
 
 # dh_installdeb will replace this with shell code automatically
 # generated by other debhelper scripts.