Affects Version/s: None
Fix Version/s: 2.0
PooledObject#compareTo only returns 0 if the getLastRuntime values are equal AND the identityHashCodes are equal.
This will work OK for the identity comparison, but is not guaranteed to work in all other cases.
It's possible for two distinct objects to have the same identityHashCode.
If such objects happen to have the same lastRuntime, then compareTo will return 0, but equals (which defaults to Object#equals) will return false.
It's not very likely, but it is possible.
A simple fix would be to define equals() to return true only in the case that the lastRuntime values and identityHashCodes are equal.
Also, the Javadoc for the compareTo method ought to make clear what the ordering is intended to achieve.