inittab: Start shell only if console is not null

[Harald Becker]

> But I didn't know this. So it seems that if I use "console" as the id,
> the device open succeeds when the system boots with console=ttyS0 but
> fails when booting with console=null (not sure why -- shouldn't it be
> possible to open /dev/null ?).

Have not looked into code, but I ought it depends on the special 
function of the console.
If you specify null as tty it usually succeeds, but if you give the name 
of a device which fail on open (as with console=null) the entry is skipped.

Harald