rebase: set `prepared = True` at very end of `_preparenewrebase()` Once we've set `rebaseruntime.prepared = True`, `rebaseruntime.repo` starts returning the unfiltered repo. That will make my next patch break, because that patch moves the call to `rewriteutil.precheck()` after the call to `_handleskippingobsolete()`, which current happens after `prepared = True`. We therefore need to prepare by moving `prepared = True` a bit later, after `_handleskippingobsolete()`. I don't think that matters for that call. Differential Revision: https://phab.mercurial-scm.org/D10257

rebase: filter out descendants of divergence-causing commits earlier `hg rebase` treats obsolete commits differently depending what has happened to the commit: 1) Obsolete commit without non-obsolete successors: Skipped, and a note is printed ("it has no successor"). 2) Obsolete commit with a successor in the destination (ancestor of it): Skipped, and a note is printed ("already in destination"). 3) Obsolete commit with a successor in the rebase set: The commit and its descendants are skipped, and a note is printed ("not rebasing <commit> and its descendants as this would cause divergence"), unless `allowdivergence` config set. 4) Obsolete commit with a successor elsewhere: Error ("this rebase will cause divergences"), unless `allowdivergence` config set. Before this patch, we did all those checks up front, except for (3), which was checked later. The later check consisted of two parts: 1) filtering out of descendants, and 2) conditionally printing message if the `allowdivergence` config was not set. This patch makes it so we do the filtering early. A consequence of filtering out divergence-causing commits earlier is that we rebase commits in slightly different order, which has some impact on tests. Differential Revision: https://phab.mercurial-scm.org/D10249

rebase: clarify names of variables and function related to obsolete revisions Differential Revision: https://phab.mercurial-scm.org/D10248