RE: show whitespace problems by default in diff-mode

["Drew Adams" <drew.adams@oracle.com>]

> Trailing whitespace is an annoyance most of the time,

That's the question - is it? For most Emacs users most of the time? Dunno; just
asking.

> and it's not to be conflated with the rest of the whitespace
> differences (which diff-mode can ignore just fine -- C-c C-w).

Yes, I know, which is why I didn't conflate them. I mentioned both, in case
there is also some desire to deal with whitespace in general this way.

There could be a `diff' switch (or a pseudo-`diff' switch, handled only by
Emacs) for trailing whitespace. Just as patch submitters need to get the `diff'
switches right for context diff etc. (`-c -w' or whatever), so could they set
the switch to show trailing whitespace.

>   > I don't have a particular axe to grind, here. It's just 
>   > not clear that most people will want to show whitespace
>   > diffs (or even trailing whitespace) most of the time.
>   > If you can support that claim, then sure, go for it.
> 
> I have yet to see anyone that wants to have trailing whitespace (which
> are the only thing that might post is concerned with), but it's common
> to see patches being rejected, or people asked to fix the patches
> because of trailing whitespace problems.  Making it easy to 
> spot and fix such issues just helps our users.

As I see it, the claim is still not supported. The question is about most Emacs
users of `diff' most of the time. You seem to be addressing the population of
most submitters of Emacs patches most of the time that they submit an Emacs
patch (or other patch where trailing whitespace is a no-no). Those aren't the
same thing.

Again, I don't know whether your claim might also be true for most Emacs users
of `diff' most of the time. But you haven't supported that, at least.

(And yes, I'm likely to be bit by this gotcha, myself. The question still should
be about Emacs users of `diff' in general, not about Emacs patch submitters.)