changegroup: move deltaparent() from narrow I'm not keen on performing the attribute sniff to test for presence of ellipses mode: I'd rather we use a separate packer instance that was ellipses mode specific. But I've tried to formalize a better API without narrow in core and I can't make sense of all the monkeypatching. My goal is to inline as much of the monkeypatching as possible then refactor the changegroup generation API. We add this code to the cg2packer because narrow doesn't work with cg1. Differential Revision: https://phab.mercurial-scm.org/D4062

changegroup: move _packellipsischangegroup() from narrow The behavior here is not ideal, as the function constructs a packer then adds attributes to it. This will be cleaned up in subsequent commits. Moving this code is necessary to move the remainder of the bundle2-level changegroup part generation code into core. Differential Revision: https://phab.mercurial-scm.org/D4061