X-Git-Url: http://nitlanguage.org

diff --git a/lib/privileges.nit b/lib/privileges.nit
index d91a9a6..f17a28e 100644
--- a/lib/privileges.nit
+++ b/lib/privileges.nit
@@ -47,16 +47,20 @@ class UserGroup
 	# Group name
 	var group: nullable String
 
-	# Drop privileges of a user and set his privileges back to default (program privileges)
+	# Drop privileges of the running program to those of `self`
+	#
+	# require: `user.user_exists and (group == null or group.group_exists)`
 	fun drop_privileges
 	do
 		var passwd = new Passwd.from_name(user)
+		assert not passwd.address_is_null
 		var uid = passwd.uid
 
 		var group = group
 		var gid
 		if group != null then
 			var gpasswd = new Group.from_name(group)
+			assert not gpasswd.address_is_null
 			gid = gpasswd.gid
 		else gid = passwd.gid
 
@@ -71,8 +75,11 @@ class OptionUserAndGroup
 
 	redef type VALUE: nullable UserGroup
 
-	init for_dropping_privileges do init("Drop privileges to user:group or simply user", "-u", "--usergroup")
-	init(help: String, names: String...) do super(help, null, names)
+	# Create an `OptionUserAndGroup` for dropping privileges
+	init for_dropping_privileges
+	do
+		init("Drop privileges to user:group or simply user", null, ["-u", "--usergroup"])
+	end
 
 	redef fun convert(str)
 	do
@@ -83,8 +90,7 @@ class OptionUserAndGroup
 			return new UserGroup(words[0], words[1])
 		else
 			errors.add("Option {names.join(", ")} expected parameter in the format \"user:group\" or simply \"user\".\n")
-			abort # FIXME only for nitc, remove and replace with next line when FFI is working in nitg
-			#return null
+			return null
 		end
 	end
 end