Problems in KWayland causes by API and ABI compatibility promises

[Vlad Zahorodnii]

Hi,

On 3/24/20 6:55 PM, David Edmundson wrote:
> I just had a near miss with XdgOutputV1(version2) which luckily we
> were able to easily guard. Had the spec claimed that in version2
> sending xdg_output.name was mandatory we would have been completely
> screwed.

Unfortunately, I have bad news. We're screwed. I poked people to clarify 
the language that is used in many specs. Here's the summary: if a spec 
says that an event is sent after creating an object and nowhere it says 
that the event is optional, then the compositor _must_ send the event.

xdg_output::description is an optional event because the spec mentions 
it. On the other hand, xdg_output::name is mandatory because the spec 
has no a single word about it being optional.

Cheers,
Vlad