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

rebase: calculate obsolescense-related info earlier My goal is to use `rewriteutil.precheck()` in the rebase code. Since rebase does its own handling of divergent commits (it skips them instead of erroring out), we need to have divergence-causing commits filtered out early. This patch helps prepare for that. Differential Revision: https://phab.mercurial-scm.org/D10247

rebase: let _handleskippingobsolete(self) read directly from self The function already has `self` as an argument, so there's no need to pass data from `self` into it. Differential Revision: https://phab.mercurial-scm.org/D10246

tests: test divergence created during interrupted rebase If a rebase runs into conflicts and the user somehow rewrites an unrebased commit in the rebase set while the rebase is interrupted, continuing it might result in divergence. It turns out that we decide to skip the commit. That seems to make sense, but it wasn't obvious to me that that's what we should do. Either way, this patch adds a test case for the current behavior. Differential Revision: https://phab.mercurial-scm.org/D10256

tests: split up test-rebase-obsolete.t in four pieces The test case took 42 seconds to run the test before this patch and 12 seconds after (wall time, of course). Differential Revision: https://phab.mercurial-scm.org/D10255

path: error out if the `path://` reference point to an unknown path Differential Revision: https://phab.mercurial-scm.org/D10265