This change makes it so we rebase descendants based on the rewrite
information recorded in `MutableRepo` instead of using evolution for
it. This is an important step towards removing evolution (#32).
When we remove evolution (#32), I don't intend to replicate the hack
it had for rebasing descendants onto a split commit. Let's instead
have `jj split` manually rebase descendants of the original commit
onto the second part of the split. We use `DescendantRebaser` for
that. Branches and the working copy pointing to the split commit are
still updated using evolution in
`RepoCommandHelper::finish_transaction()`. I plan to have
`DescendantRebaser` update branches and working copies as well. That
should then also work as expected for `jj split`.
This change makes `jj squash` and `jj unsquash` record the child or
parent (respectively) as abandoned if it becomes empty. We need to do
that because it won't get automatically recorded by
`CommitBuilder`. We could make `CommitBuilder` record abandoned
commits when `set_pruned()` was called, but that would be
short-sighted since we're about to delete that function as part of
removing support for evolution (#32).
After writing a new working copy commit, we update branches pointing
to it, and we rebase descendants on top. However, we should be doing
that in the opposite order, so the branch updates apply to rewritten
descendants as well.
This makes it so that almost every command will remove non-visible
heads. That shouldn't have much visible effect, except that the
`all_heads()` revset will become the same as
`non_obsolete_heads()`.
It will help us remove support for evolution by cleaning up existing
repos. Existing repos (like mine) will lose the unwanted heads (~8.5k
heads in my case), so they don't clutter the repo once evolution is
gone.
This is part of issue #32.
This change makes it so `jj abandon` uses `DescendantRebaser` for
rebasing descendants of the abandoned commits. That makes it not
depend on evolution for it.
Descendants of abandoned commits should be rebased onto their parents,
or the rewritten parents if they had been rewritten. This patch
teaches `DescendantRebaser` to do that. It updates `jj rebase -r` to
use the functionality. I plan to also use it in `jj abandon`
(naturally, given the name), and for rebasing descendants of deleted
refs imported from `jj git refresh/fetch/push`.
The command's help text says "Abandon a revision", which I think is a
good indication that the command's name should be `abandon`. This
patch renames the command and other user-facing occurrences of the
word. The remaining occurrences should be removed when I remove
support for evolution.
This makes conflicted branches pointing to the working copy get
updated when the working copy changes, just like they are when it
changes for other reason (such as `jj describe`).
This patch moves the function for updating branches after rewrite from
`commands.rs` into `rewrite.rs`.
It also changes the function to update branches even if they were
conflicted or become conflicted. I think that seems better than
leaving branches on old commits. For example, let's say you have start
with this:
```
C main
|
B origin@main
|
A
```
You now pull from origin, which has updated the main branch from B to
B'. We apply that change to both the remote branch and the local
branch, which results in a conflict in the local branch:
```
C main?
|
B B' main? origin@main
|/
A
```
If you now rewrite C to C', the conflicted main branch will still
point to C, which is just weird. This patch changes that so the
conflicted side of main gets repointed to C'.
I also refactored the code to reuse our existing
`MutableRepo::merge_single_ref()`, which improves the behavior in
several cases, such as the conflict-resolution case in the last test
case.
I don't know why I hadn't already updated these. Maybe I thought it
wasn't necessary. That's probably true right now, but I want to make
`jj git fetch` and `jj git refresh` automatically rebase commits when
branches were updated on a remote or in the underlying Git repo. We
want to make sure that the working copy also gets updated then.
I forgot to remove the `fetch_head` from a variable name when I
recently realized that Git's `FETCH_HEAD` is not what we want to check
out after fetching.
It turns out that `FETCH_HEAD` is not the remote's `HEAD` (it's
actually not even a normal symbolic ref; it contains many lines of
commits and names). We're supposed to ask the remote for its default
branch instead. That's what this patch does.
It's annoying to have to add `--branch main` every time I push to
GitHub.
Maybe we should make it push only the current branch by default, but
we don't even have a concept of a current branch yet...
I'm not sure what the interface should be, but until public heads are
automatically removed when they disappear from a remote, this will at
least be useful as a workaround.
For example:
```
main: 4f2efc5bb873 cli: make `jj branches` say how much remote branches are ahead/behind
@origin (behind by 2 commits): 5023d8d360 Merge pull request #26 from martinvonz/git-comparison
```
It turns out that `--help` provides a longer version of the help text
than `-h` does. I only discovered that because I was wondering what
the difference between `clap::App::about()` and
`clap::App::long_about()` was. There's clap-rs/clap#1015 for tracking
it in clap, but let's clarify it ourselves for now by changing the
help text for `-h/--help`.
With this commit, you can run `jj concepts branches` to get help about
the "branches" concept. We don't have much help for other commands and
their arguments yet, but I'm starting with concept guides so we can
point to them as we add help for commands and their arguments.
I initially tried to make the command to get help be `jj help
--concept branches`. That would require replacing clap's
implementation of the help command with our own. clap-rs/clap#1350
prevented me from doing that. But I'm pretty happy with having it
under `jj concepts` anyway. It's probably more discoverable that way.
I tried to mimic clap's styling with yellow headings.
Clap uses present tense by default (e.g. "Prints help information"). I
considered switching our message to that style, but I found it harder
to describe some flags that way.
I think it makes sense to have a version of rebase that rebases the
descendants of the rebased commit onto the parents of the rebased
commit. Let's make `jj rebase -r` do just that. Let's also add `jj
rebase -s` (matching Mercurial's `hg rebase -s`) for rebasing a commit
and its descendants onto another commit.
Since both flavors of the command now explicitly rebase the
descendants (just to different destinations), I also made the command
not evolve orphans afterwards. That would have made sense regardless
of this commit.
This change makes `jj status` include a section about conflicted local
branches and another section about conflicted remote branches. They
show up only if there are conflicts. They include hints about how to
resolve.
The auto-rebasing of descendants doesn't work if you have an open
commit checked out, which means that you may still end up with orphans
in that case (though that's usually a short-lived problem since they
get rebased when you close the commit). I'm also about to make
branches update to successors, but that also doesn't work when the
branch is on a working copy commit that gets rewritten. To fix this
problem, I've decided to let the caller of `WorkingCopy::commit()`
responsible for the transaction.
I expect that some of the code that this change moves from the lib
crate to the cli crate will later move back into the lib crate in some
form.
I want to reuse this bit of code for evolving descendants of a
rewritten working copy commit.
I expect this to change again soon (I'll probably make it do a regular
rebase instead of evolve), but this will do for now.
This makes it so (local) branches get updated when the commit they
point to gets rewritten. If the branch was conflicted, we just print a
warning and don't update the branch (though one could imagine
rewriting the conflict). We also just print a warning if the new
target is unclear because the commit was rewritten into multiple new
commits (divergent).
The updating doesn't work when the working copy commit gets rewritten
because the working copy changed on disk. That's because that's done
in a separate transaction inside `working_copy.rs`. That's similar to
how orphans of the working copy commit don't get automatically
evolved. I'll fix both problems soon.
