Re: write-region docstring/behavior inconsistency

[Richard Stallman]

    The documentation for write-region says that START and END should be
    buffer positions, but auto_save_1 calls it with START and END being
    nil.  There is an inconsistency here.  

That means those arguments are omitted.  They default to the
whole buffer.

    If write-region should grok nil for START and/or END, should all
    filename handlers be checked so that they do so, as well?

Yes.