Works for me:

    > c = console
    Console {  }
    > window.console = {}
    Object {  }
    > c.log("hello")
    undefined
    "hello"

If you could provide specific steps-to-reproduce and/or a test case, then dropping those in a bug is the best way to get the behavior fixed: https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox&c...