copies: simplify merging of copy dicts on merge commits After we removed some filtering in 35d674a3d5db (copies: don't filter out copy targets created on other side of merge commit, 2019-04-18), we will always include all entries from "copies1", so we can simplify the code based on that. Differential Revision: https://phab.mercurial-scm.org/D6561

copies: remove a redundant matcher filtering in _changesetforwardcopies() We filter before pushing items on the queue, so we don't need to filter after popping. Differential Revision: https://phab.mercurial-scm.org/D6560

copies: delete obsolete comment in _changesetforwardcopies() IIRC, the comment applied to the filtering we did before 35d674a3d5db (copies: don't filter out copy targets created on other side of merge commit, 2019-04-18). Differential Revision: https://phab.mercurial-scm.org/D6559

merge with stable

copies: avoid reusing the same variable for two different copy dicts "childcopies" is initally the copies the current changeset to one of its children and then we reassign it with the copies from the start of the chain to the child. Let's use different names for these two things. Differential Revision: https://phab.mercurial-scm.org/D6564

drawdag: don't crash when writing copy info to changesets When writing copies to the changeset, localrepo.commitctx() will call ctx.p1copies() and ctx.p2copies(). These crashed on simplecommitctx because they ended up trying to access the manifest. drawdag doesn't support copies at all, so we can simply override the methods to return empty dicts. Differential Revision: https://phab.mercurial-scm.org/D6565

merge with stable