uncommit: simplify condition for keeping commit We used to keep the commit if it would have become empty and --keep was not passed. Since we just changed it so we also keep it if any patterns were passed on the command line, the only remaining case where we prune the commit is when no arguments were passed and --keep was not passed either, we can simplify the "not files and not allowempty" to just "not allowempty". Let's also rename "allowempty" to "keepcommit" since it's no longer about allowing an empty commit. Differential Revision: https://phab.mercurial-scm.org/D2891

uncommit: document when the commit will be pruned Differential Revision: https://phab.mercurial-scm.org/D2890

uncommit: leave empty commit if all files are uncommitted We had instructions for our internal users to add copy information after commit like this: hg uncommit <srcfile> <dstfile> hg cp --after <srcfile> <dstfile> hg amend That usually works, but if the rename was the only change in that commit, then the commit would get pruned. It's easy to fix the recipe: just pass the --keep option. However, it seems too subtle, so I think this is an indication that the commit should not be pruned if any patterns were given. Differential Revision: https://phab.mercurial-scm.org/D2862

test-template-engine: do not evaluate unused keywords by custom engine If the custom engine, "mytemplater", were installed as the default, it would enter to an infinite recursion at stringify(v) because template keywords may generate a nested mapping containing the same keywords. Spotted by a future patch which will replace context.resource('templ')(...) with context.process(...).

py3: make test-template-engine.t bytes-safe

test-template-engine: deduplicate methods of custom template engine

revbranchcache: advertise and use 'rbc' exchange capability The feature is now advertised and use. Updating the branchmap cache can be very expensive (up to minutes on large repository) and fetching revision branch data is about 80% of that. Exchanging the rev branch cache over the wire really help to recover from branch map invalidation. (There is a good chance other in flight chance would conflict on test-http-bad-server.t and other. So here is a small note to help update that test again: capabilities=19bytes, part-107bytes)