bug#30397: Random numbers in grep mode-line

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

> > But `C-h m' says nothing about this (it should).
> >
> > And clicking `compilation-mode' (the parent) in the `C-h m' output
> > shows that mode's doc, but it too says nothing about this.
> 
> I don't see modes whose "C-h m" tells anything about mode-line
> indicators.  Do you?

No. And?

How many modes do you see that have mode-line info
that needs explanation?  There might well be some
others - in that case, feel free to file bugs for
those too.

The point is that if something the mode does is not
obvious from the UI, it might help for the mode doc
to say something about it.

For `grep', in particular, these numbers, even with
their mouseover tooltips, may leave users scratching
their heads.

Juri is hardly a novice, to either Emacs or `grep'.
I'm not that much of a novice either.  We both,
apparently, feel that this mode-line indication is
not sufficiently self-expanatory.  There may even
be some question (e.g. for `grep') how useful it is.

If you agree that better help about this would be
in order, where would you suggest putting that help,
if not on `C-h m'?  (If you don't agree that
improvement is needed then why ask about putting it
on `C-h m'?)