https://bugs.winehq.org/show_bug.cgi?id=42412
--- Comment #4 from bobben@wigilius.se --- Forgot to add, that the log output with +winsock is from downloading a 1.2Mb file from my local file server over FTP.
The downloaded file ended up at 1230701 bytes, with the original file being 1230727 bytes, that is with the default MTU of 1500. Lowering the MTU will eventually get me to one byte from the original size, but never spot on.