Draft: [RFC] Xorg-only release branches

The last major X server release has been done more than three years ago on May 2018. Since March 2021 the Xwayland DDX has been released as a separate sub-project with its own release schedule that does not depend on the X server as a whole.

There are new features in the Xorg DDX that I would like to see released, so I'm volunteering to do the releasing work.

XWayland has established a good practice (see !582 (closed)) of cutting single-DDX releases.

The following proposal is basically a copy-paste of Michel's work with replacement of xwayland with xorg-server.

Proposal

• Xorg and Xvfb DDXen are released using the DDX-only release process together.
• New Xorg development continues on the master branch. Everything applicable must land there first, in order to prevent divergent forks of DIX code.
• When there are new Xorg features ready to ship, a new stable xorg-server-<year>.<minor> branch can be forked off from the master branch, and parts of the tree which aren't used by Xorg or Xvfb can be pruned from that branch.
• Bug fixes can be backported from master to xorg-server-x.y the same way as for the existing server-1.y-branch stable branches.
• The initial major release and subsequent minor releases are made from the xorg-server-x.y branch.
• For release cadence, make a .1 release in Q1 of each year, and if there are new features available by Q3, optionally make a .2 release as well. Releases should be aimed to align with regular Q1/Q3 distribution releases.
• One xorg-server-<year>.<minor> branch will be active at any time in general.
• There may be one final x.y.z release from the previous branch after the next x.y.0 release though.

Contents of this MR

Just like !582 (closed), this MR drops all DDXen that are not Xorg or Xvfb and builds Xorg unconditionally. The name of the project is not changed as it's xorg-server already.

Impact for other DDXen

There should be no direct impact, since Xorg-only releases would be made from separate branches, and development continues on the master branch.

If there's a new full xserver major release in the future, Xorg should probably be excluded from it.

Downstream impact

The implementation of this proposal has exactly the same impact to the downstreams as the Xwayland-only releases. Distributions may still decide to ship Xorg and other DDXen from git with all the consequences, or may attempt to integrate Xorg, Xvfb and Xwayland from the DDX-specific xwayland-x.y and xorg-server-x.y stable releases plus other DDXen from the last stable 1.20.x release series.