All kinds of reversers (just like planes) and all kinds of logic and safe guards.
However, with the lessons learned in most transport jets, an unwanted reverser deployment can be bad news. Thus the need for weight on wheels switches, reverser unlock switches and FCOM manuals of what to do.
Simply as one poster has already said if below V1 abort, if above V1 bring the engine to idle ... and leave it there. (one guy didn't and upon reapplying thrust the reverser deployed)
Most protection logic in the design should auto-command a stow of the reverser for a simple unlock light warning if there is no weight on wheels. However its still up to the pilot to command the engine to idle.