Not a KTorrent user, but saw this and thought I would mention it.

Just been on a swarm, and had some code so that I could see what reserved bits various clients were sending as part of their BT handshake. I saw one KTorrent peer (I think it was a 2.0 peer) which was setting the 5th bit (indexing from 0) in each byte.

In hexadecimal format, the reserved bits looked like this: 0404040404040404

Does KTorrent still do that? Is it meant to do that?

Current code doesn't do this. I had a look at the 2.0 code and it seems that we indeed did this, so it's an old bug.