Re: [gmane.emacs.bugs] Emacs fails to start properly if the current working directory is on a vfat or ntfs filesystem

[Richard Stallman]

    There's no need to investigate, as the problem is clearly evident:
    Windows-based filesystems don't allow certain characters in file
    names, and `*' is one of these characters.  So a file name such as
    `#*scratch*#20913s5z#' is not allowed.

If this were just a minor problem, it would make sense to say "use a
different name".  But this is such a painful and broad problem that it
is worth fixing if possible.

One possible solution would be for Fdo_auto_save to detect that errno
code when `open' fails, and modify the file name.  Maybe it should
also set a flag which Lisp code can see.