This moves the logic for handling the root commit when writing commits
from `CommitBuilder` into the individual backends. It always bothered
me a bit that the `commit::Commit` wrapper had a different idea of the
number of parents than the wrapped `backend::Commit` had.
With this change, the `LocalBackend` will now write the root commit in
the list of parents if it's there in the argument to
`write_commit()`. Note that root commit itself won't be written. The
main argument for not writing it is that we can then keep the fake
all-zeros hash for it. One argument for writing it, if we were to do
so, is that it would make the set of written objects consistent, so
any future processing of them (such as GC) doesn't have to know to
ignore the root commit in the list of parents.
We still treat the two backends the same, so the user won't be allowed
to create merges including the root commit even when using the
`LocalBackend`.
The `CommitBuilder::store` field is used only in
`CommitBuilder::write_to_repo()`, but we can easily get access to the
`Store` from the `repo` argument there, so let's remove the field.
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.
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.
This patch introduces a `JJ_TIMESTAMP` environment variable that lets
us specify the timestamp to use in tests. It also updates the tests to
use it, which means we get to simplify the tests a lot now that that
the hashes are predictable.
The recent e5dd93cbf712, whose description says "cleanup: make Vec
inside CommitId etc. non-public", made all ID types in the `backend`
module *except* for `CommitId` non-public :P This patch makes
This is part of removing support for evolution (#32). Since
`CommitBuilder` now records rewritten commits in `MutableRepo`, we can
use that recorded information to automatically rebase descendants.
I suspect that at least one reason that I didn't make
`MutableRepo::base_repo` by an `Arc<ReadonlyRepo>` before was that I
thought that that would mean that `start_transaction()` would need be
moved off of `ReadonlyRepo` so it can be given an
`&Arc<ReadonlyRepo>`, which would make it much less convenient to
use. It turns out that a `self` argument can actually be of type
`&Arc<ReadonlyRepo>`.
Most methods on `Transaction` only need the `MutableRepo`, so it makes
for that functionality to be on the latter. That will let us update
the methods to also update the index, which would otherwise have been
harder because it would require a mutable borrow of both the view and
the index. This patch makes most current methods on `Transaction` just
delegate to `MutableRepo`. We may want to remove some of these
delegating methods later.
