I ran an upgraded Clippy on the codebase. All the changes seem to be
about using variables directly in format strings instead of passing
them as separate arguments.
This will be a building block of 'parents(base)' revset. 'base---' will
be .filter_by_generation(3..4) for example. I think 'ancestors(base)' can
also have an optional generation parameter, but I haven't considered any
particular syntax yet.
This basically transforms 's1 & (f() | s2)' to
's1.iter().filter(all && f || s2)'. Still the predicate part includes "all",
the filter function doesn't need to load commit data for every entry since
's1.iter().filter(all)' is tested first. To optimize "all" predicate out,
maybe we can add a wrapper that returns '|_: &IndexEntry| true'.
Instead of inserting AsFilter(_) node, I could add a recursive is_filter()
function. That would also work so long as the height of RevsetExpression tree
is limited. I chose node insertion just for ease of snapshot testing.
@yuja asked on #701 about the difference between the state in the
`git_export_view` and what we have in `mut_repo.view()`. It's true
that the branches in `mut_repo.view().git_refs()` should match what we
wrote to disk. We can therefore remove the on-disk storage and
simplify quite a bit. For now, I create the `last_export_view` from
the `mut_repo.view().git_refs()` before calling
`export_changes()`. I'll clean up a bit more next.
I think this is correct even considering e.g. undo. Let's consider
what would happen in a non-colocated Git repo (not because tricky
cases cannot happen there but because the explicit exports and imports
make it easier to discuss, and more cases can occur). If the user
moved a branch and then did `jj git export`, `jj undo`, and then `jj
git export` again, we would think on the second export that we should
perform the same changes to the Git repo, which should have no effect.
This patch also fixes the bug we were forced to work around in the
test case in the previous patch.
This removes one of our uses of Thrift.
This fixes the bugs shown by the tests added in the previous patch by
checking that the git branches we're about to update have not been
updated by git since our last export. If they have, we fail those
branches. The user can then re-import from the git repo and resolve
any conflicts before exporting again.
I had to update the `test_export_import_sequence` to make it
pass. That shows a new bug, which I'll fix next. The problem is that
the exported view doesn't get updated on import, so we would try to
export changes compared to an earlier export, even though we actually
knew (because of the `jj git import`) that the state in git had
changed.
If you update a branch using regular `git` (or some Git-based tool)
between two `jj git export`, we will overwrite that change if you had
also changed the branch in jj land. There's a similar problem if you
delete the branch in jj land. Let's have a test for that. I'm going to
make us not overwrite it soon. This patch adds a test for those cases,
plus many other cases in consistent way. Since the new test covers
some cases tested by existing tests, I removed those tests.
It seems that we didn't have a test for this simple case. I wrote this
test case while working on #111 but I don't know why I didn't push it
back then.
A new FileType, GitSubmodule is added which is ignored. Files or
directories having this type are not added to the work queue and
are ignored in snapshot. Submodules are not created by jujutsu
when resetting or checking out a tree, they should be currently
managed using git.
Because a unary negation node '~y' is more primitive than the corresponding
difference node 'x~y', '~y' is easier to deal with while rewriting the tree.
That's the main reason to add RevsetExpression::NotIn node.
As we have a NotIn node, it makes sense to add an operator for that. This
patch reuses '~' token, which I feel intuitive since the other set operators
looks like bitwise ops. Another option is '!'.
The unary '~' operator has the highest precedence among the set operators,
but they are lower than the ranges. This might be counter intuitive, but
useful because a prefix range ':x' can be negated without parens.
Maybe we can remove the redundant infix operator 'x ~ y', but it isn't
decided yet.
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.
Follows up c5ed3e1477. Now change/commit ids are resolved at the same
precedence, which means there are at least three types of ambiguity.
I don't think we would need to discriminate these.
Because the use of the change id is recommended, any operation should abort
if a valid change id happens to match a commit id. We still try the commit
id lookup first as the change id lookup is more costly.
Ambiguous change/commit id is reported as AmbiguousCommitIdPrefix for now.
Maybe we can merge AmbiguousCommit/ChangeIdPrefix errors into one?
Closes#799
The CLI will load aliases from config, insert them one by one, and warn if
declaration part is invalid. That's why RevsetAliasesMap is a public struct
and needs to be instantiated by the caller.
To reduce conflicts between branches like `main` and `main/sub`, it's
better to first delete refs in git that have been deleted in jj, and
then add/update refs that have been added/updated in jj.
Since we now write a (partial) view object of the exported branches to
disk (since 7904474320), we can safely skip exporting some
branches. We already skip conflicted branches. This commit makes us
also skip branches that we fail to write to the backing Git repo,
instead of failing the whole operation (after possibly updating some
Git refs).
I made the `export_refs()` function return the branches that
failed. We should probably make that a struct later and have a
separate field for branches that we skipped due to conflicts.
Closes#493.
This adds a test for attempting to export both a branch called `main`
and one called `main/sub` (#493), as well as for exporting a branch
with an empty string as name (reported directly to me by @lkorinth).
The expression 'x ~ empty()' is identical to 'x & file(".")', but more
intuitive.
Note that 'x ~ empty()' is slower than 'x & file(".")' since the negative
intersection isn't optimized right now. I think that can be handled as
follows: 'x ~ filter(f)' -> 'x & filter(!f)' -> 'filter(!f, x)'
There are no "non-normal" files, so "normal" is not needed. We have
symlinks and conflicts, but they are not files, so I think just "file"
is unambiguous.
I left `testutils::write_normal_file()` because there it's used to
mean "not executable file" (there's also a `write_executable_file()`).
I left `working_copy::FileType::Normal` since renaming `Normal` there
to `File` would also suggest we should rename `FileType`, and I don't
know what would be a better name for that type.
We currently get the hostname and username from the `whoami` crate. We
do that in lib crate, without giving the caller a way to override
them. That seems wrong since it might be used in a server and
performing operations on behalf of some other user. This commit makes
the hostname and username configurable, so the calling crate can pass
them in. If they have not been passed in, we still default to the
values from the `whoami` crate.
When we export branches to Git, we didn't update our own record of
Git's refs. This frequently led to spurious conflicts in these refs
(e.g. #463). This is typically what happened:
1. Import a branch pointing to commit A from Git
2. Modify the branch in jj to point to commit B
3. Export the branch to Git
4. Update the branch in Git to point to commit C
5. Import refs from Git
In step 3, we forgot to update our record of the branch in the repo
view's `git_refs` field. That led to the import in step 5 to think
that the branch moved from A to C in Git, which conflicts with the
internal branch target of B.
This commit fixes the bug by updating the refs in the `MutableRepo`.
Closes#463.
As I said in the previous patch, I don't know why I made the initial
export to Git a no-op. Exporting everything makes more sense to
(current-)me. It will make it slightly easier to skip exporting
conflicted branches (#463). It also lets us remove a `jj export` call
from `test_templater.rs`.
To fix#463, I think we want to skip conflicted branches when we
export instead of erroring out. It seems we didn't have test case for
the current behavior, so let's add one.
This is a test case for #463. It's not exactly the same case, but I'm
confident that the root cause is the same (that the
`.jj/repo/git_export_operation_id` doesn't include the git refs we
just updated).
These calls often appear in expressions long enough that not having to
qualify it means that we can sometimes avoid wrapping a line. I
noticed because IntelliJ told me that `test_git.rs` had some
unnecessary qualificiations (the function was already imported there).
The `testutils` module should ideally not be part of the library
dependencies. Since they're used by the integration tests (and the CLI
tests), we need to move them to a separate crate to achieve that.
If you remove all refs from the backing Git repo and then run `jj git
import`, we would see that all commits disappeared from the Git repo,
so we would remove them from the jj repo too. However, we do that by
doing a history walk from old heads to the new heads, which includes
the root commit when the new heads is an empty set. That means that we
mark the root commit as abandoned, which led to a crash in
`rewrite.rs` (when we try pick the root commit's first parent to use
as parent for rebased commits).
I was trying to create a reproduction script for #412, but the script
ran into another bug first. The script removed all the local and
remote branches from the backing Git repo. I noticed that we would
then try to abandon all commits. We should still count Git HEAD's
target as visible and not try to abandon it. This patch fixes that.
Since 'merges()' just filters the candidates set per item, it doesn't need
a candidates argument. Perhaps, 'merges(x)' could be a predicate to select
merge commits within a subgraph 'x', but I don't know if that would be
useful.
Since d56ae79d3f, `WorkingCopy` no longer reads `.gitignores`
directly from `$HOME/.gitignore`, so we don't need the workaround to
prevent it in the tests.
More workspace-derived parameters will be added, and I don't think wrapping
with Option for each makes sense because all parameters should be available
if workspace exists.
Let WorkspaceCommandHelper clone it. WorkspaceCommandHelper could return
workspace_id by reference, but doing that would introduce noisy .clone()
calls and lifetime mess.
This changes `RepoLoader` to take a map of functions that load a
specific type of backend, keyed by the backend type. The backend type
is read from `.jj/repo/store/backend`.
The `ReadonlyRepo::init_*()` functions were unused or used only in
tests. Let's remove them, thereby making the repo less aware of
specific backend implementations.
In many of these places, we don't need an owned value, so using a
reference means we don't force the caller to clone the value. I really
doubt it will have any noticeable impact on performance (I think these
are all once-per-repo paths); it's just a little simpler this way.
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`.
I feel the original -------/+++++++ pair is slightly confusing because
each half can be a separator by itself. I don't know what character other
than '-'/'+' is preferred, but let's pick '%' (for "mod") per @martinvonz
suggestion.
`wc_commit` seems clearer than `checkout` and not too much longer. I
considered `working_copy` but it was less clear (could be the path to
the working copy, or an instance of `WorkingCopy`). I also considered
`working_copy_commit`, but that seems a bit too long.
This will be a basic building block of 'jj log PATH'. The implementation
is naive, but works fine for small repos like jj. For mid-size repos,
there would be various areas which need to be optimized.
Otherwise a file could be created out of the working copy directory.
This only works for untracked symlinks and sequentially "added" symlinks
and files. For "removed" and "modified" entries, the parent directories are
considered valid and fs::remove_file() will be called. This also doesn't
prevent race conditions caused by concurrent checkouts.
New create_parent_dirs() would be slightly slower than the original because
it traverses directories from the root whereas fs::create_dir_all() does that
from the leaf and exits when reached to a directory.
One advantage of our conflict marker style (compared to the usual
3-way markers) is that they provide the user with the diff between the
base and one side so the user doesn't have to do that in their head
(which is how I use 3-way markers anyway). However, since we currently
always use the "first" side for the diff, that diff can be larger than
if we had picked the other side, which makes the marker style worse
than the usual 3-way markers. This has bothered me many times and it's
about time we fix it.
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.
When rebasing commits after rewrites, we also update all workspaces'
checkouts. If the new commit is closed, we create a new commit on
top. Since we're hoping to remove the open/closed concept, we need a
new condition. I considered creating a new commit on top if the change
ID was different from before the rewrite. However, that would make at
least `jj split` more complicated because it makes the first commit
keep the change ID but it wants the second commit to be checked
out. This patch instead creates the new commit on top only when the
original commit was abandoned.
This patch makes us treat special files (e.g. Unix sockets) as absent
when snapshotting the working copy. We can consider later reporting
such files back to the caller (possibly via callback) so it can inform
the user about them.
Closes#258
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.
We don't even have any settings that affect the repo, so there's no
point in passing the settings. I think this was a leftover from before
we separated out the "workspace" concept; now we no longer create a
working-copy commit when we initialize a repo (we do that when we
attach the workspace).
The request to show the log output with more recent commits at the
bottom comes up once in a while (among Mercurial users, and now also
for jj from @arxanas). It's pretty easy to implement by adding an
adapter to the current `RevsetGraphIterator`. It works by first
collecting all nodes and edges into a vector and then yielding them in
reverse order and with reversed edges. That means it's no longer lazy,
but that seems fine since the feature is optional. Also, it's only the
subset of nodes that are in the selected revset that will be
collected.
Making the CLI use the new iterator adapter will come in a later
patch.
I think I copied the name `write_tree()` from Git, but I find it quite
confusing, since it's not clear if it write a tree to the working copy
or reads the working copy and writes a tree to the store (it's the
former).
Now that I'm using GitHub PRs instead of pushing directly to the main
branch, it's quite annoying to have to abandon the old commits after
GitHub rebases them. This patch makes it so we compare the remote's
previous heads to the new heads and abandons any commits that were
removed on the remote. As usual, that means that descendants get
rebased onto the closest remaining commit.
This is half of #241. The other half is to detect rewritten branches
and rebase on top.
Let's say we have a simple history like this:
```
B C D
\|/
A
```
Branch `main` initially points to commit B. Two concurrent operations
then move the branch to commits C and D. When the two concurrent
operations get merged, the branch will be recorded as pointing to
"C+D-B". If a subsequent operation now abandons commit B, we would
update the "removed" side of the branch conflict. That seems a little
dishonest. I think the reason I did it that way was in order to not
keep B visible back when having it present in the "removed" side would
keep it visible (before 33bf6ce1d5).
I noticed this issue while working on #241 because
`test_import_refs_reimport()` started failing. That test case is
pretty much exactly the case above.
This patch makes room for sparse patterns in the `TreeState` proto
message. We also start setting that value to a list of just the
pattern `.` when we create new working copies. Old working copies
without the sparse patterns are also interpreted as having that single
pattern. Note that this absence of sparse patterns is different from a
present list of no patterns. The latter is a valid state and means
that no paths are included in the sparse checkout.
The `DescendantRebaser` keeps a map of branches from the source
commit, so it gets efficient lookup of branches to update when a
commit has been rebased. This map was not kept up to date as we
rebased. That could lead to branches getting left on hidden
intermediate commits. Specifically, if a commit with a branch was
rewritten by some command, and an ancestor of it was also rewritten,
then we'd only update the branch only the first step and not update it
again when rebasing onto the rewritten ancestor.
When a directory is missing in one merge input (base or one side), we
would consider that a merge conflict. This patch changes that so we
instead merge trees by treating the missing tree as empty.
This introduces a `connected(x)` function, which is simply the same as
`x:x`. It's occasionally useful if `x` is a long expression. It's also
useful as a building block for `root(x)` (coming soon).
We do it for all the other kinds of objects already. It's useful to
have the path for backends that store objects by path (we don't have
any such backends yet). I think the reason I didn't do it from the
beginning was because we had separate `RepoPath` types for files and
directories back then.
We depend on comparing the workspace root with the Git repo's path to
know if we're sharing the working copy with it. For that to work
reliably, we need the paths to be canonicalized, so that's what this
patch tries to do.
There was a TODO about adding a test case for a delete/modify conflict
in a branch target that got resolved by abandoning a commit. The
resolution is to delete the branch. That case couldn't happend with
our old evolution-based mechanism for tracking rewrites (because we
couldn't un-prune a commit then).
If we have recorded in `MutableRepo` that commits have been abandoned
or rewritten, we should always rebase descendants before committing
the transaction (otherwise there's no reason to record the
rewrites). That's not much of a risk in the CLI because we already
have that logic in a central place there (`finish_transaction()`), but
other users of the library crate could easily miss it. Perhaps we
should automatically do any necessary rebasing we commit the
transaction in the library crate instead, but for now let's just have
a check for that to catch such bugs.
It's unusual for the current commit to have descendants, but it can
happen. In particular, it can easily happen when you run `jj new`. You
probably don't want to abandon it in those cases.
The library crate shouldn't look up the user's `$HOME` directory
(maybe the library is used by a server process), so let's have the
caller pass it into the library crate instead.
We no longer need the commit ID, so we shouldn't make the callers pass
it. This lets us simplify several tests, because they no longer to
create commits just to check out a tree in the working copy.
We used to use the value to detect races, but we use the tree ID and
the operation ID these days, so we don't need the commit ID.
By changing this, we can avoid creating some commit IDs in tests,
which is why I tackled this issue now.
There are only two callers of `LockedWorkingCopy::check_out()`. One is
in `commands.rs`. That caller already checks after taking the lock
that the old commit ID is as expected. The other caller is
`WorkingCopy::check_out()`. We can simply move the check to that level
since it's the only caller that cares now.
We resolve checkouts in favor of the first-committed operation (which
is more likely to have managed to update the working copy). The test
case has been flaky on GitHub lately. I've run it 1000 times on my
machine without failure. I don't know if GitHub's machines are just
faster in some way (SSD, maybe) that makes them finish the two
operations in the test in the same millisecond. Let's add a
1-millisecond sleep to see if that helps. If it doesn't, then maybe
the issue is that the clock has lower precision (or their clocks can
go backwards?).
`LockedWorkingCopy::discard()` shouldn't result in changes to the
on-disk state, but `LockedWorkingCopy::check_out()` may have already
written a state file, which is surprising. The changes also remain in
memory, which is also surprising. Let's fix both of those issues.
One of the .gitignore tests writes a tree from the working copy
twice. However, it discards the `LockedWorkingCopy` instance after the
first write, so the second write shouldn't really see the changes from
the first write. It does see them because we don't clear them in
memory (and we also surprisingly write them to disk). I'm about to fix
that, so the test needs to be fixed first.
Most tests need a repo but don't need a working copy. Let's have a
function for setting up a test repo. But first, let's free up the name
`init_repo()` by renaming it to `init_workspace()` (which is also more
accurate).
As part of creating a new repository, we create an open commit on top
of the root and set that as the current checkout. Now that we have
support for multiple checkouts in the model, we also have support for
zero checkouts, which means we don't need to create that commit on top
of the root when creating the repo. We can therefore move out of
`ReadonlyRepo`'s initialization code and let `Workspace` instead take
care of it. A user-visible effect of this change is that we now create
one operation for initilizing the repo and another one for checking
out the root commit. That seems fine, and will be consistent with the
additional operation we will create when adding further workspaces.
Because we record each workspace's checkout in the repo view, we can
-- unlike other VCSs -- let the user refer to any workspace's checkout
in revsets. This patch adds syntax for that, so you can show the
contents of the checkout in workspace "foo" with `jj show foo@`. That
won't automatically commit that workspace's working copy, however.
When checking out a new commit, we look at the old checkout to see if
it's empty so we should abandon it. We current use the default
workspace's checkout. We need to respect the workspace ID we're given
in `MutableRepo::check_out()`, and we need to be able to deal with
that workspace not existing yet (i.e. this being the first checkout in
that workspace).
The `.jj/` directory contains information about two distinct parts:
the repo and the working copy. Most subdirectories are related to the
repo; only `.jj/working_copy/` is about the working copy. Let's move
the repo-related bits into a new `.jj/repo/` subdirectory. That makes
it clearer that they're related to the repo. It will probably also be
easier to manage when we have support for multiple workspaces backed
by a single repo.
The `DescendantRebaser` was designed to help with rebasing in two
different use cases: 1) after regular rewriting of commits where the
change ID is preserved, and 2) after importing moved branches from
other repo (e.g. backing Git repo or remote). Many of the tests are
for the second use case, such as where a branch was moved
forward. However, I just noticed that there's a pretty common scenario
from the first use case that is not supported.
Let's say you have this history:
```
D
|
C C'
|/
B B'
|/
A
```
Here we want C' to be rebased onto B' and then D to be rebased onto
C''. However, because of the support for moving branches forward, we
would not rebase commits that were already rewritten, such as C' here
(see affected tests for details), which resulted in D getting rebased
onto C', and both B and B' remaining visible.
I think I was thinking when I designed it that it would be nice if you
could just tell `DescendantRebaser` that any descendants of a commit
should be moved forward. That may be useful, but I don't think we'll
want that for the general case of a branch moving forward. Perhaps
we'll want to make it configurable which branches it should happen
for. Either way, the way it was coded by not rebasing already
rewritten commits did not work for the case above. We may be able to
handle both cases better by considering each rewrite separately
instead of all destinations at once. For now, however, I've decided to
keep it simple, so I'm fixing the case above by sacrificing some of
the potentially useful functionality for moving branches forward.
Another fix necessary for the scenario shown above was to make sure we
always rebase C' before D. Before this patch, that depended on the
order in the index. This patch fixes that by modifying the topological
order to take rewrites into account, making D depend not only on C but
also on C'. (I suppose you could instead say that C depends on both B
and C'; I don't know if that'd make a difference.)
Despite what the documentation said, we don't clear the record of
rewritten and abandoned commits at the end. This change fixes that,
and adds a test showing that it's possible to call
`MutableRepo::rebase_descendants()` multiple times.
When there are concurrent operations that want to update the working
copy, it's useful to know which operation was the last to successfully
update the working copy. That can help use decide how to resolve a
mismatch between the repo view's record and the working copy's
record. If we detect such a difference, we can look at the working
copy's operation ID to see if it was updated by an operation before or
after we loaded the repo.
If the working copy's record says that it was updated at operation A
and we have loaded the repo at operation B (after A), we know that the
working copy is stale, so we can automatically update it (or tell the
user to run some command to update it if we think that's more
user-friendly).
Conversely, if we have loaded the repo at operation A and the working
copy's record says that it was updated at operation B, we know that
there was some concurrent operation that updated it. We can then
decide to print a warning telling the user that we skipped updating
because of the conflict. We already have logic for not updating the
working copy if the repo is loaded at an earlier operation, but maybe
we can drop that if we record the operation in the working copy (as
this patch does).
`WorkingCopy::check_out()` currently fails if the commit recorded on
disk has changed since it was last read. It fails with a "concurrent
checkout" error. That usually works well in practice, but one can
imagine cases where it's not correct. For an example where the current
behavior is wrong, consider this sequence of events:
1. Process A loads the repo and working copy.
2. Process B loads the repo at operation A. It has not loaded the
working copy yet.
3. Process A writes an operation and updates the working copy.
4. Process B loads the working copy and sees that it is checked out
to the commit process B set it to. We don't currently have any
checks that the working copy commit matches the view's checkout
(though I plan to add that).
5. Process B finishes its operation (which is now divergent with the
operation written by process A). It updates the working copy to
the checkout set in the repo view by process B. There's no data
loss here, but the behavior is surprising because we would usually
tell the user that we detected a concurrent update to the working
copy.
We should instead check that the working copy's commit on disk matches
what the previous repo view said, i.e. the view at the start of the
operation we just committed. This patch does that by having the caller
pass in the expected old commit ID.
We already have two usecases that can be modeled as updating the
`TreeState` without touching the working copy:
1. `jj untrack` can be implemented as removing paths from the tree
object and then doing a reset of the working copy state.
2. Importing Git HEAD when sharing the working copy with a Git repo.
This patch adds that functionality to `TreeState`.
This patch changes the interface for making changes to the working
copy by replacing `write_tree()` and `untrack()` by a single
`start_mutation()` method. The two functions now live on the returned
`LockedWorkingCopy` object instead. That is more flexible because the
caller can make multiple changes while the working copy is locked. It
also helps us reduce the risk of buggy callers that read the commit ID
before taking the lock, because we can now make it accessible only on
`LockedWorkingCopy`.
`WorkingCopy::current_commit()` has been there from the beginning. It
has made less sense since we made the repo view keep track of the
current checkout. Let's remove it.
If you import Git refs, then rebase a commit pointed to by some Git
ref, and then re-import Git refs, you don't want the old commit to be
made a visible head again. That's particularly annoying when Git refs
are automatically updated by every command.
I recently (0c441d9558) made it so we don't create an operation when
nothing changed. Soon thereafter (94e03f5ac8), I broke that when I
introduced a cache-invalidation bug when I made the filtering-out of
non-heads be lazy. This patch fixes that and also adds a test to
prevent regressions.
This patch adds a place for tracking the current `HEAD` commit in the
underlying Git repo. It updates `git::import_refs()` to record it. We
don't use it anywhere yet.
This is part of #44.
I'm about to change `ReadonlyRepo::load()` to take the path to the
`.jj/` directory, so this patch prepares for that. It already works
because `ReadonlyRepo::load()` will search up the directory tree for
the `.jj/` entry.
`ReadonlyRepo::init_*()` currently calls `WorkingCopy::init()`. In
order to remove that dependency, this patch wraps the
`ReadonlyRepo::init_*()` functions in new `Workspace` functions. A
later patch will have those functions call `WorkspaceCopy::init()`.`
The `Repo` doesn't do anything with the `WorkingCopy` except keeping a
reference to it for its users to use. In fact, the entire lib crate
doesn't do antyhing with the `WorkingCopy`. It therefore seems simpler
to have the users of the crate manage the `WorkingCopy` instance. This
patch does that by letting `Workspace` own it. By not keeping an
instance in `Repo`, which is `Sync`, we can also drop the
`Arc<Mutex<>>` wrapping.
I left `Repo::working_copy()` for convenience for now, but now it
creates a new instance every time. It's only used in tests.
This further decoupling should help us add support for multiple
working copies (#13).
The recent e5dd93cbf7, 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
A while ago, I replaced a call to git2-rs's `Remote::fetch()` by calls
to `Remote::download()` and `Remote::update_tips()`. The function is
documented to be a convenience for those function, but it turns out
that the pruning of deleted remote refs is a separate call
(`Remote::prune()`), so we need to call that too.
Since the working copy can now handle conflicts, we don't need to
materialize conflicts when checking out a commit.
Before this patch, we used to create a new commit on top whenever we
checked out a commit with conflicts. That new commit was intended just
for resolving the conflicts. The typical workflow was the resolve the
conflicts and then amend. To use the same workflow after this patch,
one needs to explicitly create a new commit on top with `jj new` after
checking out a commit with conflict.
I realized only recently that we can try to parse conflict markers in
files and leave them as conflicted if they haven't changed. If they
have changed and some conflict markers have been removed, we can even
update the conflict with that partial resolution.
This change teaches the working copy to write conflicts to the working
copy. It used to expect that the caller had already updated the tree
by materializing conflicts. With this change, we also start parsing
the conflict markers and leave the conflicts unresolved in the working
copy if the conflict markers remain.
There are some cases that we don't handle yet. For example, we don't
even try to set the executable bit correctly when we write
conflicts. OTOH, we didn't do that even before this change.
We still never actually write conflicts to the working copy (outside
of tests) because we currently materialize conflicts in
`MutRepo::check_out()`. I'll change that next.
I initially made the working copy materialize conflicts in its
`check_out()` method. Then I changed it later (exactly a year ago, on
Halloween of 2020, actually) so that the working copy expected
conflicts to already have been materalized, which happens in
`MutableRepo::check_out`().
I think my reasoning then was that the file system cannot represent a
conflict. While it's true that the file system itself doesn't have
information to know whether a file represents a conflict, we can
record that ourselves. We already record whether a file is executable
or not and then preserve that if we're on a file system that isn't
able to record it. It's not that different to do the same for
conflicts if we're on a file system that doesn't understand conflicts
(i.e. all file systems).
The plan is to have the working copy remember whether a file
represents a conflict. When we check if it has changed, we parse the
file, including conflict markers, and recreate the conflict from
it. We should be able to do that losslessly (and we should adjust
formats to make it possible if we find cases where it's not).
Having the working copy preserve conflict states has several
advantages:
* Because conflicts are not materialized in the working copy, you can
rebase the conflicted commit and the working copy without causing
more conflicts (that's currently a UX bug I run into every now and
then).
* If you don't change anything in the working copy, it will be
unchanged compared to its parent, which means we'll automatically
abandon it if you update away from it.
* The user can choose to resolve only some of the conflicts in a file
and squash those in, and it'll work they way you'd hope.
* It should make it easier to implement support for external merge
tools (#18) without having them treat the working copy differently.
This patch prepares for that work by adding support for parsing
materialized conflicts.
While working on demos, I noticed that `jj log` output in the
octocat/Hello-World repo was unstable: sometimes the first parent of
the merge was on the left and sometimes it was on the right. This
patch fixes that by sorting the edges by position in the index just
before returning them. It seems that most applications would want
stable output so I put it in the `RevsetGraphIterator` rather than
doing at the call site in the CLI. I ordered them with the reverse
index position rather than forward because it seemed to make the
graphs in the git.git repo slight nicer, with the left-most edge going
between subsequent releases.
There performance difference is within the noise level.
If you rewrite a commit that's also available on some remote, you'll
currently see both the old version and the new version in the view,
which means they're divergent. They're not logically divergent (the
rewritten version should replace the old version), so this is a UX
bug. I think it indicates that the set of current heads should be
redefined to be the *desired* heads. That's also what I had suspected
in the TODO removed by this change. I think another indication that
we should hide the old heads even if they have e.g. a remote branch
pointing to them is that we don't want them to be rebased if we
rewrite an ancestor.
So that's what I decided to do: let the view's heads be the desired
heads. The user can still define revsets for showing non-current
commits pointed to by e.g. remote branches.
This fixes a bug I've run into somewhat frequently. What happens is
that if you have a conflict on top of another conflict and you resolve
the conflict in the bottom commit, we just simplify the `Conflict`
object in the second commit, but we don't try to resolve the new
conflict. That shows up as an unexpected "conflict" in `jj log`
output, and when you check out the commit, there are actually no
conflicts, so you can just `jj squash` right away.
This patch fixes that bug. It also teaches the code to work with more
than 3 parts in the merge, so if there's a 5-way conflict, for
example, we still try to resolve it if possible.
With this change, you can do e.g. `heads(remote_branches())`. That
should currently be the same as `public_heads()`, except that we don't
yet remove public heads when remote branches have been updated. Having
this support should be generally useful, but I may use it in the short
term specifically for depending less on the public heads, until I get
around to keeping them up to date.
It's been a lot of work, but now we're finally able to remove the
`Evolution` state! `jj obslog` still works as before (it just walks
the predecessor pointers).
The removal of hidden heads was just there to help with the transition
away from evolution (#32). Now that we no longer depend on evolution
for removing old heads, we can remove the hack.
This patch teaches `DescendantRebaser` to also update heads. That's
done at the end of the rebase (when `rebase_next()` starts returning
`None`), which is a little weird. We should probably change the
interface, but this will do for now.
With this change, we should no longer need to remove hidden heads when
the transaction commits. That will remove one of the last bits of
dependence on evolution from most commands (#32).
Now that we remove hidden heads whenever a transaction commits,
`non_obsolete_heads()` should always be the same as `all_heads()`,
except during a transaction. I don't think we depend on the difference
even during a transaction. Let's simplify a bit by removing the revset
function `all_heads()` and renaming `non_obsolete_heads()` to
`heads()`. This is part of issue #32.
This is similar to how a recent change taught `DescendantRebaser` to
update branches pointing to rewritten commits. Now we also update the
checkout if it pointed to a rewritten commit.
This patch moves the logic for updating branches from
`update_branches_after_rewrite()` into `DescendantRebaser`. The
branches are now updated along with each rebased commit rather than
all being updated at the end. The new code uses the information about
rewritten and abandoned commits that `DescendantRebaser` gets from
`MutableRepo`. That is different from the old code, which used the
evolution state. This patch thus moves us one step closer to removing
evolution (#32).
I'm going to teach `DescendantRebaser` to also update local branches
pointing to rewritten commits, taking over the responsibility from
`rewrite::update_branches_after_rewrite()`. For commits that have been
rewritten as multiple new commits (divergent, not split), that
function makes local branches pointing to the old commit point to all
the new commits. To replicate that behavior in `DescendantRebaser`, it
needs to know about divergent changes. This change addresses that.
I recently made the CLI remove hidden heads when a transaction is
committed (38474a9). Let's move that to `Transaction::commit()`, so
the library crate becomes more similar to how the CLI behaves and more
similar to our evolution-less future (#32).
The next patch would otherwise make this test fail because
"transaction 2" tries to point a branch to a commit that's not visible
(because it's created by the concurrent "transaction 1").
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.
When we remove support for evolution (#32), we need to still make it
easy for application code to rebase descendants of rewritten and
abandoned commits. The way applications currently do that is by using
e.g. `CommitBuilder::for_rewrite_from()` followed by
`evolve_orphans()`. This patch puts some bookkeeping in `MutableRepo`
for rewritten and abandoned commits, along with a function for
creating a `DescendantRebaser` based on it. I'll then make
`CommitBuilder` record rewritten commits there.
The default branch relies on checking the value of `HEAD`. The `empty_git_commit` function updates the ref `refs/heads/main`, but since `HEAD` was never updated to point to that ref, the default branch can't be determined. The fix is to explicitly set `HEAD`.
Personally, this test failed reliably for me on macOS. I don't know why this behavior would be non-deterministic on other platforms.
It seems it wasn't Windows that behaved differently when it comes
getting the remote's default branch; the test failed on Ubuntu
too.
The documentation for `Remote::default_branch()` says that it can be
called even after the connection has been closed, but let's see if
calling it while the connection is open helps anyway. To do that, we
have to replicate what `Remote::fetch()` does.
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 fact that `DescendantRebaser` visits some commits that don't need
to be rebased is mostly an implementation detail. I can't think of a
reason that callers would care about these commits.
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 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.
As the updates test case shows, when rebasing forward, we missed
commits that fork off from the section between the source and the
destination.
As part of the fix, I also restructured the code a bit to prepare for
support for rebasing descendants of multiple rewritten commits.
Before this change, you could end up with an index segment with 10
commits, then a child segment with 9 commits, then another child with
8 commits, and so on. That's not what I had intended. This changes
makes it so we squash if a segment has more than half as many commits
as its parent instead.
Git doesn't want `.git` entries in its trees, so at least when using
the Git backend, we need to ignore such paths. Let's just ignore
`.git` paths regardless of backend to keep it simple.
Closes#24.
When I added the function for rebasing descendants, I forgot to call
the existing `rebase()` function and instead simply created a new
commit with the new parents but the old contents.
This should be useful in lots of places. For example, `jj rebase -r`
currently rebases all descendants, because that's what the auto-evolve
feature does. I think it would be nice to instead copy from
Mercurial's `-s` flag for also rebasing descendants. Then `jj rebase
-r` can be made to pull a commit out of a stack, rebasing descendants
onto the rebased commit's parents. I also intend to use this
functionality for rebasing descendants when remote branches have been
rewritten.
