Late API change to KWayland for upcoming Frameworks release

[Martin Flöser]

Am 2018-05-02 06:19, schrieb Roman Gilg:
> I have the following patch to KWayland adding a property for per
> OutputDevcie color correction via color curve adjustment:
> https://phabricator.kde.org/D12388
> 
> The problem is that Frameworks tag is on Saturday, but if the patch
> does not get in with next Frameworks release, I'm blocked on multiple
> other patches for KWin and Plasma that otherwise could land in 5.13.
> 
> There seems to be an unwritten rule against API changes to Frameworks
> in the last week before tagging, but since KWayland is an independent
> framework only relevant to the fast-moving Wayland session and the
> additional code paths will only become relevant in practice with the
> upcoming changes to Plasma in 5.13 I would like to make an exception
> to this unwritten rule. Because of the unwritten rule I want to hear
> other opinions on this decision first though.
> 
> Regarding the API changes one other question: I have not increased the
> Wayland protocol version numbers of the affected protocol extensions
> in the patch, because they are only used internally and KScreen as
> well as KWin will just ignore the additional property functioning as
> before as long as no support has been added to them with a future
> Plasma release. Is this alright?

No, we need to be compatible and should follow the common Wayland way. 
If we add requests, we increase the version. I just pointed that out in 
the review.

What's worse is that you added the events/requests in between which is 
not API compatible.

Like what David said in the phab request: don't rush. In the worst case 
everything is delayed, in the half-worst case you need compile time 
checks in kwin and remove them once we branched 5.13.

Cheers
Martin