bug#70587: More buffers that ought to be read-only

[Stefan Monnier]

> Does it mean you will not be terribly mad if I remove the read-only
> setting from "M-x diff", and let it behave as every other client of
> diff-mode?

I don't have a strong opinion on this, no (diff-mode buffers are
among those where I use `C-x C-q` most frequently).

`C-x v =` is an important "client of diff-mode" (arguably more
important than `M-x diff`), and it does make `*vc-diff*` read-only,
so if you want to change `M-x diff`, I suggest you change `C-x v =` at
the same time.


        Stefan