Re: show whitespace problems by default in diff-mode

[Dan Nicolaescu <dann@ics.uci.edu>]

"Drew Adams" <drew.adams@oracle.com> writes:

  > > 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.

Yes, it is, please go to your favorite search engine and search for 
trailing whitespace patch or trailing whitespace diff and see you many
hits you get.

  > > 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.

No, there isn't, I intentionally limited the topic to one thing because
of not wanting to have a long discussion that ends nowhere.  So please
stick to the topic at hand.

  > 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.

There isn't such a flag, and more, users might not use diff, but
vc-diff.