The native backend is just a proof of concept and there's no real
reason to use it other than for testing, so let's reduce the risk of
accidentally creating repos using it.
By adding `ui.open-commits=false` in your config, you can now make `jj
checkout` always create a new working-copy commit on top of the
specified commit. If the config is set, open commits will also appear
in the same color as closed commits in `jj log` etc. This will let
some of us experiment with the new UX before we decide if it's a good
idea or not. I left `jj close` in place because it's useful for
setting a description and creating a new commit in one step.
I didn't mention the new config in the release notes because I hope we
can reach a decision and remove the config before the next release.
If a commit's author field has the placeholder user/email values
(i.e. "(no name configured)" and "(no email configured)"), and they
have now configured their email and username, they probably want us to
update the author field with the new information, so that's what this
patch does. Thanks to durin42@ for the suggestion on #322.
I'm not sure it'll be useful, but it seems nice to be able to set the
same values via config or environment variables. Perhap we should
simply use `config::Environment` to make everything configurable via
environment variables, but I'll leave that for later.
It's useful to have `signature()` live on `UserSettings` because that
will let us cache information (such as the timestamp) in the
instance. It will also make it easier to have the timestamp settable
via regular config files. I don't know that that will be useful, but
it seems like a clean way of implementing it if we can have
environment variables simply as an overlay of configs.
