branching: merge with stable

changelog: add missing entry for 9af212b8565a

evolve: test that target is not orig in _solveunstable() (issue6097) `newer` is the result of obsutil.successorssets() and can be [[orig.node()]], in which case later on in this function evolve will try to rebase orig onto orig, which is not correct. So let's just check this particular case. This fix doesn't cover cases when successorssets() result contains orig.node() not at [0][0]. Such cases need tests.

tests: demonstrate an orphan changeset cause "relocate node on top of itself" See issue6097.

obslog: only indent the first chunk and chunks just after newlines (issue6175)

tests: demonstrate too many spaces in olog -p output with word-diff

rewind: add --keep flag that "doesn't modify working directory" The actual logic is more complicated than the flag description, but it's sufficiently similar to other --keep flags in action. Unlike strip (or prune), rewind always needs to modify the working directory to commit new revisions that "revive" old ones [1], see _revive_revision() (and rewriteutil.rewrite()). Because of that we don't prevent rewind from modifying wdir, but instead use hg.updaterepo() to update to the old changeset after the "revival" process is complete. Then we rebuild the dirstate based on the commit that rewind would update to without --keep. Since dirstate.rebuild() doesn't restore status of some files (added, removed, also copies and renames), we rely on cmdutil.revert(). It's a fairly crude solution and needs to be removed when implementing the missing copy tracing between oldctx and newctx (which are related only by obsolescence). [1] IOW this means that --keep doesn't allow rewinding if wdir is dirty (unlike e.g. strip).