bug#3250: 23.0.93; tab completion flakey with tramp when insert-default-directory is nil

[Chong Yidong]

Chris Withers <chris@simplistix.co.uk> writes:

>>> -(setq insert-default-directory nil) in .emacs
>>> -restart
>>> C-x C-f
>>> ..
>>> - then try using tab completion
>>
>> Pressing TAB shows the contents of my home directory.  This is expected
>> behavior.  What behavior do you observe?
>
> Did you do the all important '..' to go to a parent directory?

After typing `..', I type TAB.  The text in the minibuffer completes to

  ../

After typing TAB again, Emacs offers a completions list showing the
directories in /home.  This is expected.