setdiscovery: rearrange code deciding if we will grow the sample The new code is clearer and will make the next update simpler. Differential Revision: https://phab.mercurial-scm.org/D10232

debugdiscovery: document relevant config option These config option are here for people to experiment with it. So lets document them in the command that is used for experimentation. Differential Revision: https://phab.mercurial-scm.org/D10231

re2: feed unicode string to re2 module when necessary My previous test were using the `pyre2` Python project, that wrap the Google RE2 library in python as a `re2` module and accept bytes as input. However the `fb-re2` Python project is also offering a wrapping of the Google RE2 library in python as a `re2` module ans accept only unicode on python3. So we detect this situation and convert thing to unicode when necessary. Hooray… We should consider using a rust wrapping for regexp handling. We needs regexps in Rust anyway and this give use more control with less variants and more sanity. Differential Revision: https://phab.mercurial-scm.org/D10284

rebase: skip obsolete commits even if they have pruned successors Issue 5782 reported that `hg rebase -r <obsolete commit with pruned successor>` failed with an error saying that it would cause divergence. Commit b7e2cf114e85 (rebase: do not consider extincts for divergence detection (issue5782), 2018-02-09) fixed it by letting you rebase the commit. However, that fix seems inconsistent with how we handle `hg rebase -r <pruned commit>`. To me, it should make no difference whether a commit is pruned itself or if it has (only) pruned successors. This patch changes it so we treat these two kinds of commits the same way. I let the message we print remain "note: not rebasing <commit>, it has no successor" even though that last part is not technically correct for commits with pruned successors. I doubt it will confuse users. Differential Revision: https://phab.mercurial-scm.org/D10240