This is following on the rewrite for `parallelize`.
- https://github.com/martinvonz/jj/pull/3521
Since rebase_descendants from rebase.rs is no longer used outside of that file,
it can be made private again.
This is the same as the `test_split_siblings_with_merge_child` added in
https://github.com/martinvonz/jj/pull/3485, but without the siblings flag. I
forgot to add the non-siblings version in that PR.
#3485
Ilya reported this in https://github.com/martinvonz/jj/issues/3483.
The bug was introduced in 976320726d.
Before this fix, `jj split` dropped any parents what weren't involved in the
split when it rebased the children of the commit being split. This meant that
any children which were merge commits lost their other parents unintentionally.
Fixes#3483
When a commit is split, any branches pointing to it are moved to the second
commit created by the split. This is true even if the --siblings option is
used.
#3419
If the --siblings option is used, the target commit is split into two sibling
commits instead of parent and child commits. Any children of the original
commit will have both siblings as their new parents.
#2274
It's inconsistent that some warnings have headings and some don't, and it seems
the choice is arbitrary. Let's unify the style. There are two exceptions:
1. continued line following labeled message,
2. "unrecognized response" followed by prompt.
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.
At some point, I tried `new_commit` instead of `rewrite_commit` in the split
command. That seemed to work, but messed up the dates in a subtle way.
This commit should prevents repeats of this mistake and emphasize the
importance of the author dates being preserved.
One use case for `jj split` is when creating a new commit from some of
the changes in the working copy. If there's no description on the
working-copy commit in that case, it seems better to not ask the user
to provide one when they're splitting the commit either.
