bug#44617: 26.3; diff-mode ignores diff-switches

[Francesco Potortì]

>> diff-mode relies on the diff-command variables defined in diff.el, but
>> ignores diff-switches
>>
>> I think this is a bug
>
>Do you mean the `diff-refresh-hunk' command?

No, it's a different issue.

>What's the use case you have for diff-switches where you'd want this
>command to heed diff-switches?

I have two use cases.

1) When using dired-diff (hit = in a dired buffer) diff-switches is not used.

2) Same is when using vc-diff (C-x v =) in a VC buffer.

Apparently case 2) is a bug, because the docs of vc-diff-switches says
that diff-switches should be used.  Case 1) could simply be unexpected
behaviour.