This allows us to use "if(description,)" to test empty description. And
I think this change is unavoidable if we want to add support for commit
template.
Otherwise the description set by -m would differ from the one set by editor.
This fixes test_describe() which says "make no changes", but previously "\n"
would be added by the second "jj describe".
As you can see, almost all hashes change in CLI tests. This means in-flight
PRs will need to be rebased to update insta snapshots.
Description text could be normalized by CommitBuilder, but the caller would
have to normalize it beforehand to compare with the current description, so
we would need an explicit function anyway. Another idea is to add a newtype
that represents a normalized description, and make CommitBuilder require it.
Commit::description() will return &Description in place of &str to ensure
that commit.description() == raw_str wouldn't compile.
Git CLI provides --cleanup=<mode> option to switch normalization rules, but
I don't think we'll need such feature.
Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
It seems simpler to do the snapshotting after merging any concurrent
operations instead of snapshotting on top of one of the operations,
especially since the attempt to snapshot may end up noticing that the
working copy is stale.
More importantly, snapshotting before resolving operations resulted in
a crash if the working copy was modified. That happened because we
held a lock on the operation heads (`locked_op_heads`) while we tried
to record the operation committing the working copy. I noticed this
only after adding the test.
It can be confusing that some commits (typically the working copy)
don't have a description. Let's show a placeholder text in such cases.
I chose the format to match the "(no email configured)" message we
already have.
It's useful for testing to be able to specify some operation that's
not the latest one.
I didn't update the changelog because this feature is mostly for
testing.
This involved copying `UnresolvedHeadRepo::resolve()` into the CLI
crate (and modifying it a bit to print number of rebased commit),
which is unfortunate.
