On IRC it is confusing when an XMPP user "corrects" a message, but on
the other side a new message is sent. To prevent spam and confusion, do
not allow message corrections at all, and instead return an error if
attempted.
Fixes: #3436Fixes: #3480
This has the following advantages:
- Works while all resources are offline (persistent channels)
- Helps with combating duplicate messages when sent to different
resources, resources going offline, carbon-copying etc. etc.
As a side effect, this also makes the MUC PMs not be MUC PMs and
always be emitted from the server-wide JID of the sending user.
Fixes#3313.
Because we actually don’t change the nick, we ignore it, just like in the
case of a normal join (of an other resource, or an other channel on the same
server).
Some duplication is avoided, but most importantly: it’s much much cleaner,
easier to find, functions have been cleaned up (functools.partial usages are
now hidden), etc.
Luca Matei Pintilie