util.signal: Fix signalfd closure on non-Linux systems The loop was incorrect for 0-indexed arrays. It started at signalfd_num, which is the total number of signalfds, and decremented to 1 (condition was >0). So if 1 signalfd was registered, it would check only signalfds[1]. At capacity (32 signalfds) it would read past the end of the array. In every case, it would always skip the entry at position [0], leading to a leak. The swap-with-tail removal of the matched item used the post-decrement operator, leading to accessing the array slot just beyond the tail. Finally, it didn't break after finding a match. Probably harmless, but there isn't expected to be more than a single entry per fd, as far as I can tell.

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local st = require "prosody.util.stanza";

module:add_feature("urn:xmpp:ping");

local function ping_handler(event)
	event.origin.send(st.reply(event.stanza));
	return true;
end

module:hook("iq-get/bare/urn:xmpp:ping:ping", ping_handler);
module:hook("iq-get/host/urn:xmpp:ping:ping", ping_handler);