I've encountered that if you receive a file via dcc from two different sources (same file), both will be accepted and you'll end up with a bigger than original end file, plus corrupted.

I've seen it happen both on beta 16 & 19 (on 16 I waited till the download was completed and saw it was corrupted while on 19 I just noticed the dual send still happened, but didn't want to pursue pointless downloading)

Sorry if this was already discussed.

Thanks this has been fixed for the next version.