merge.mergestate: set merge driver state to 's' if there's none present This allows mergestate.mdstate() to return 's' if there's nothing to be done on the merge driver end.

merge.mergestate: only check for merge driver when property is accessed Otherwise 'hg update --clean', 'hg rebase --abort' etc wouldn't work.

localrepo.commit: abort if merge driver's conclude step hasn't been run yet This case also requires 'hg resolve --all' to be run before continuing.

merge.mergestate: add a way to get the merge driver state This will be useful to check what the status of the merge driver is.

merge.mergestate: add a way to get the other side of the merge It's surprising there was no API at all for this until now. In any case this will be needed from custom merge drivers.

commands.resolve: support printing out driver-resolved files There's no user-visible way to mark files as driver-resolved, so this status won't be visible.

histedit: make histedit prune when obsolete is enabled Back in June we made histedit use obsolete markers to cleanup when possible. This was rolled back as part of 54f9561088c7 (which should have only rolled back the --abort stuff, but rolled back everything). This caused a nasty bug when used in conjuction with the inhibit+directaccess extensions where histedit would leave old nodes around even after they had been squashed away. The root of the problem is that we first clean up old nodes, and then we clean up temp nodes. In the first pass, when we obsoleted old nodes, some would become unobsolete because they had temp nodes on top of them, thus making them stick around even after the histedit finished. The fix is to A) move the temp node cleanup to be before the old node cleanup (since they are topological on top of the old nodes), and B) use obsolete markers instead of stripping.

clonebundles: rewrite documentation There are a lot of considerations server operators need to know before deploying clone bundles. They should be documented. So I rewrote the extension docs to contain this information.