Environment

$ jruby -v
jruby 9.1.5.0 (2.3.1) 2016-09-07 036ce39 Java HotSpot(TM) 64-Bit Server VM 25.102-b14 on 1.8.0_102-b14 +jit [linux-x86_64]

$ uname -a
Linux localhost 4.7.5-pclos1 #1 SMP Sun Sep 25 17:05:47 CDT 2016 x86_64 x86_64 x86_64 GNU/Linux

Expected Behavior

> require 'openssl'
> 5.to_bn.prime?
 => true
> -5.to_bn.prime?
 => false

Actual Behavior

> require 'openssl'
> 5.to_bn.prime?
 => true
> -5.to_bn.prime?     
 => true                  -- should be false, this is an error for all negative primes