The `move_commits` function accepts a set of target commits to shift to
a new location given by `new_parents` and `new_children`. The roots of
the target set will be reparented onto `new_parents`. `new_children`
will then be reparented onto the heads of the target set.
The commits will be rebased in reverse topological order based on the
new set of parents of each commit, which avoids the need for multiple
sets of rebase operations.
I will be updating `rebase -r` to avoid simplifying ancestor merges in a
subsequent commit, which will cause existing tests to fail for the Git
backend due to ancestor merges with the root commit.
This lets users use "large" revsets in commands such as `jj rebase`, without
needing the `all:` modifier.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Change-Id: Ica80927324f3d634413d3cc79fbc73057ccefd8a
One less CLI revset helper. It might look odd that "jj rebase" says "Merge
failed" whereas "jj new" doesn't, but that depends on where the BackendError
is detected.
I think the user usually wants to abandon only newly empty commits. I
think they should use `jj abandon` if they want to get rid of already
empty commits. By keeping already empty commits, we don't need to
special-case the working copy and merge commits.
I think I prefer this behavior because it's less lossy. The user can
manually simplify the history with `jj rebase -s <merge commit> -d
<one of the parents>` afterwards. We can roll this change back later
if we find it annoying.
this greatly speeds up the time to run all tests, at the cost of slightly larger recompile times for individual tests.
this unfortunately adds the requirement that all tests are listed in `runner.rs` for the crate.
to avoid forgetting, i've added a new test that ensures the directory is in sync with the file.
## benchmarks
before this change, recompiling all tests took 32-50 seconds and running a single test took 3.5 seconds:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test test_working_copy'
Time (mean ± σ): 3.543 s ± 0.168 s [User: 2.597 s, System: 1.262 s]
Range (min … max): 3.400 s … 3.847 s 10 runs
```
after this change, recompiling all tests take 4 seconds:
```
; hyperfine 'touch lib/src/lib.rs ; cargo t --test runner --no-run'
Time (mean ± σ): 4.055 s ± 0.123 s [User: 3.591 s, System: 1.593 s]
Range (min … max): 3.804 s … 4.159 s 10 runs
```
and running a single test takes about the same:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test runner -- test_working_copy'
Time (mean ± σ): 4.129 s ± 0.120 s [User: 3.636 s, System: 1.593 s]
Range (min … max): 3.933 s … 4.346 s 10 runs
```
about 1.4 seconds of that is the time for the runner, of which .4 is the time for the linker. so
there may be room for further improving the times.
Note that one of the new tests panics; this is a newly discovered bug.
In Git, a commit's direct parent is allowed to also be an indirect ancestor
at the same time. `jj` currently tries to prevent this situation, but does
allow it. The correctness of `rebase -r A -d descendant_of_A` currently depends
on this jj-specific behavior; we should change that.
Cc #2600
This follows up on 3967f63 (see that commit's description for more
motivation) and e79c8b6.
In a discussion linked below, it was decided that forbidding `-r --skip-empty`
entirely is preferable to the mixed behavior introduced in 3967f63.
3967f637dc (commitcomment-133539911)
They are shown next to the change and commit id, since they are other names the
commit can be referred by.
The description is separated from the branches by a ` | ` when there are
branches, so that one can tell the branches from the description without color.
The result looks like this: 
