bug#18851: 24.4; emacs cannot be started if the current directory has been removed

[Stefan Monnier]

> The shell has no problems when the current directory has been
> removed. It can still run without needing to switch to $HOME.

The problem is that the `emacs' process only access files using absolute
file names (it basically doesn't use the process's current working
directory, because every buffer has its own "current working
directory"), so when the Emacs user thinks he's using a relative file
name, Emacs really concatenates this relative file name to the value of
`default-directory' and passes *that* to the OS.

So the current Emacs C code really has no way to access a directory/file
which is not accessible from the root directory.


        Stefan