mod_roster_command: Fix subscription when the "user JID" is a bare domain. Do not attempt to update the roster when the user is bare domain (e.g. a component), since they don't have rosters and the attempt results in an error: $ prosodyctl mod_roster_command subscribe proxy.example.com contact@example.com xxxxxxxxxxFailed to execute command: Error: /usr/lib/prosody/core/rostermanager.lua:104: attempt to concatenate local 'username' (a nil value) stack traceback: /usr/lib/prosody/core/rostermanager.lua:104: in function 'load_roster' /usr/lib/prosody/core/rostermanager.lua:305: in function 'set_contact_pending_out' mod_roster_command.lua:44: in function 'subscribe'

local allowed_presence_types = { probe = true, unavailable = true };

function filter_presence(event)
	local stanza = event.stanza;
	local presence_type = stanza.attr.type;
	if presence_type == nil or allowed_presence_types[presence_type] then
		return;
	end
	return true; -- Drop
end

module:hook("pre-presence/bare", filter_presence, 200); -- Client sending
module:hook("presence/bare", filter_presence, 200); -- Client receiving