Sending to gajim from another resource with carbon copies enabled duplicates the message.
If I use conversations on android to send to my gajim on the desktop I see the message duplicated in gajim, I think gajim should deduplicate based on the msg ids.
<!-- Incoming Mon 18 Dec 2017 19:00:29 CET -->
<message type='chat' to='apollo13@test.com/gajim.LQCZ1P3G' from='apollo13@test.com'>
<sent xmlns='urn:xmpp:carbons:2'>
<forwarded xmlns='urn:xmpp:forward:0'>
<message id='da50da97-e951-44ee-a97d-b8e5a692a0f0' type='chat' xmlns='jabber:client' from='apollo13@test.com/phone'>
<body>Asd</body>
<request xmlns='urn:xmpp:receipts'/>
<markable xmlns='urn:xmpp:chat-markers:0'/>
<origin-id id='da50da97-e951-44ee-a97d-b8e5a692a0f0' xmlns='urn:xmpp:sid:0'/>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
</forwarded>
</sent>
</message>
<message id='da50da97-e951-44ee-a97d-b8e5a692a0f0' type='chat' from='apollo13@test.com/phone'>
<body>Asd</body>
<request xmlns='urn:xmpp:receipts'/>
<markable xmlns='urn:xmpp:chat-markers:0'/>
<origin-id id='da50da97-e951-44ee-a97d-b8e5a692a0f0' xmlns='urn:xmpp:sid:0'/>
<active xmlns='http://jabber.org/protocol/chatstates'/>
<stanza-id id='fd5009ce-6c7d-44d5-9230-3a3b26c2ae68' by='apollo13@test.com' xmlns='urn:xmpp:sid:0'/>
</message>