util.stanza: Allow U+7F
Allowed by XML despite arguably being a control character.
Drops the part of the range meant to rule out octets invalid in UTF-8
(\247 starts a 4-byte sequence), since UTF-8 correctness is validated by
util.encodings.utf8.valid().
-- XEP-0307: Unique Room Names for Multi-User Chat
local st = require "util.stanza";
local unique_name = require "util.id".medium;
module:add_feature "http://jabber.org/protocol/muc#unique"
module:hook("iq-get/host/http://jabber.org/protocol/muc#unique:unique", function(event)
local origin, stanza = event.origin, event.stanza;
origin.send(st.reply(stanza)
:tag("unique", {xmlns = "http://jabber.org/protocol/muc#unique"})
:text(unique_name():lower())
);
return true;
end,-1);