Rihanna -- Gets Long Term Protection From 'Future Husband'

The man accused of stalking Rihanna -- and claiming to be her "future husband" -- must continue to stay away from her for the next 2 years ... TMZ has learned.

As we first told you ... Jonathan Whooper was arrested earlier this month for multiple trespasses at the home RiRi was renting in Pacific Palisades. A security guard at the home says Whooper claimed he was going to marry the singer.

A judge in L.A. just granted Rihanna a permanent restraining order against Whooper. He has to stay 100 yards away from her ... the same restriction as the temporary restraining order which was already in place.