push: put phase in the same bundle2 than changegroup and obsmarkers Note that the usual phase push from core will be performed in all case. But the discovery should find already in sync phase at that time. The old ways sync will be properly skipped when this logic is introduced into core.

push: put obsmarkers in the same bundle2 than changeset When client is Mercurial 3.1 and server have proper evolve version and both side have bundle2 enabled, we'll includes a part containing obsolescence markers. When obsmarkers are included to the main bundle2 push, they will failed to be pushed if the changeset failed to be pushed (and reciprocally).

push: extract obsmarkers discovery in a dedicated function The need to factorise the computation of the markers to send in a dedicated function. This prepare the inclusion of obsmarkers in an atomic bundle2 push. For now, when obsmarkers are pushed using bundle2, they are still doing it on their own, in a dedicated bundle2 push.