To duplicate:
be in SMP on latest snapshot (13w19a)
mount horse (or in my case, donkey with chest attached)
log out
log back in
suddenly, an extra [insert mount here]!
Environment
OSX 10.7.5
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06-451-11M4406)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01-451, mixed mode)
Duplicate of MC-13737, please use the search function to see if your bug has already been submitted. Currently over 56% of tickets are being closed as duplicate.