John Wiegley <jwiegley@gmail.com> schrieb am Mi., 20. Sep. 2017 um
17:38 Uhr:

> >>>>> "CP" == Clément Pit-Claudel <cpitclaudel@gmail.com> writes:
>
> CP> I'm not too sure: take the example of visual-line-mode: how do you make
> CP> that idempotent without explicitly checking whether the mode has
> already
> CP> been activated?
>
> Also, is there a motivation for introducing this new requirement, seeing as
> how we've never had such a restriction in the past?
>

Some cases I've come across (for lsp-mode, which is currently not
idempotent):
- Enabling a minor mode in both a parent and a derived mode hook.
- Restoring buffers from the desktop file.
In such cases minor modes are activated twice, causing errors if they are
not idempotent.