Re: [Emacs-diffs] emacs-26 ee512e9: Ignore buffers whose name begins with a space in save-some-buffers

[Stefan Monnier]

> "If b-o-s is t and PRED is t the buffer will be saved, unless b-o-s is
> 'always in which case it doesn't matter what PRED is, unless PRED is a
> function in which case the only thing that matters is what that function
> returns, so long as buffer has a file name."
>
> I'm exaggerating for effect, but still. I still don't quite understand
> the use of passing a boolean in for PRED.

It's historical.  `pred = t` means "all possible buffers", whereas
`pred = nil` means "all buffers where we usually want to do it" and
another value of `pred` means just those buffers selected by pred.


        Stefan