src/share/classes/com/sun/tools/javac/comp/Attr.java

*** 3018,3028 ****
              }
  
              // Check that argument types of a reference ==, != are
              // castable to each other, (JLS???).
              if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
!                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
                      log.error(tree.pos(), "incomparable.types", left, right);
                  }
              }
  
              chk.checkDivZero(tree.rhs.pos(), operator, right);
--- 3018,3029 ----
              }
  
              // Check that argument types of a reference ==, != are
              // castable to each other, (JLS???).
              if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
!                 if (!types.isEqualityComparable(left, right,
!                                                 new Warner(tree.pos()))) {
                      log.error(tree.pos(), "incomparable.types", left, right);
                  }
              }
  
              chk.checkDivZero(tree.rhs.pos(), operator, right);