revlog: don't cache parsed tuples in the C module A cached entry creates ~8 Python objects per cached changeset, which comes to around 200 Bytes per cached changeset on AMD64. Especially for operations that touch a lot of changesets, that can easily sum up to more than a 100MB of memory. Simple tests on large repositories show <2% runtime penalty for ripping out the cache, even for cache heavy operations like "hg log" for all revisions. Differential Revision: https://phab.mercurial-scm.org/D9155

fix: only check for obsolete commits in the --rev case With both `--all` and `--source`, we already exclude obsolete revisions in the revset, so there's no need to call `checkfixablectx()` in those cases. Differential Revision: https://phab.mercurial-scm.org/D9227

fix: don't include obsolete descendants with -s The `-s/--source` option is for regular users (`-r` is there for power users). If there are obsolete commits that are descendants of the given revision(s), then they almost definitely should just be left alone. That's what `hg rebase` does as well. So this patch makes it so we skip obsolete commits (including those in the input set itself). Differential Revision: https://phab.mercurial-scm.org/D9226

tests: add test showing how `hg fix -s` deals with obsolete and orphan nodes We didn't have any tests for how `hg fix -s` behaves with obsolete commits among the descendants. The next patch will change the behavior in this area. Differential Revision: https://phab.mercurial-scm.org/D9225