FULL PRODUCT VERSION :


A DESCRIPTION OF THE PROBLEM :
the code fails to compile
{code}
interface StubElement<T>{
    T getPsi();
}

abstract class StubElementBase<T> implements StubElement<T> {
    @Override
    public T getPsi() {
        return null;
    }
}

abstract class MyStubbedElement<T extends StubElementBase<?> & Runnable>  {}

{code}

error message: Error:(14, 33) java: getPsi() in aa.StubElementBase cannot implement getPsi() in aa.StubElement
  return type capture#1 of ? is not compatible with capture#2 of ?

BTW

if we would omit Runnable in type parameter declaration, then the code would compile. Moreover if  StubElementBase<T> would be an interface with default method, then the code also would compile.

THE PROBLEM WAS REPRODUCIBLE WITH -Xint FLAG: Did not try

THE PROBLEM WAS REPRODUCIBLE WITH -server FLAG: Did not try

REGRESSION.  Last worked in version 6u43

REPRODUCIBILITY :
This bug can be reproduced always.