Re: backup method

[Richard Stallman]

    If the directory permissions are 777, then you can't do any further
    operation using the file _name_ after doing the creat system call (at
    which point its name is known and accessible).  All you want to do
    with the file, you have to do via the file descriptor returned by
    creat.

I designed the patch on that basis.  The file is written using
write-region, and nothing else is written after that.

However, it's true that the modes are set separately later on.  There
is no way to avoid that without further changes in write-region.
I don't feel like writing such changes now, but in principle they
seem to be needed here.