bug#65049: Minor update to the repro steps

[Eli Zaretskii]

> Date: Mon, 28 Aug 2023 20:39:24 +0300
> Cc: juri@linkov.net, habamax@gmail.com, 65049@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 28/08/2023 19:57, Eli Zaretskii wrote:
> > Remove that?  What will happen to non-vc-root-diff clients of that?
> 
> It is my understanding that all (or almost all?) users of vc-diff and 
> other callers of vc-diff-internal use vc-root-diff just as often (and 
> don't complain about it).
> 
> There could be some exceptions, of course. Like people who use CVS 
> exclusively.
> 
> > Or do you mean remove the vc-coding-system-for-diff call, and use
> > undecided-unix instead?
> 
> That's also an option, but I'd have to see a scenario where this binding 
> changes the observed behavior.
> 
>  > If the latter, then it is sub-optimal when vc-coding-system-for-diff
> does produce non-undecided value for some reason.
> 
> The question is how often that actually happens, and how useful the 
> result is compared to the default behavior.

Even if it happens in 1% of cases, it is useful in those cases.  I
think it's a net win.