Strange problem when using default parameters

[mstoykov]

The following code (the original is the current harness/compareArray.js in tc39 which is a lot longer):

function A() {};
A.B = function () {};
function D(message = '') {
  var C = A.B;
  C([1,2,3]); // throws "Value is not an object: undefined"
};

D()

Throws "Value is not an object: undefined" at the line C is called (as commented). This does not happen if

1. A.B is used directly
2. message = '' is just message - remove the default value