forked from mirrors/jj
316ab8efb8
Previously, the function relied on both the `self.parent_mapping` and `self.rebased`. If `(A,B)` was in `parent_mapping` and `(B,C)` was in `rebased`, `new_parents` would map `A` to `C`. Now, `self.rebased` is ignored by `new_parents`. In the same situation, DescendantRebaser is changed so that both `(A,B)` and `(B,C)` are in `parent_mapping` before. `new_parents` now applies `parent_mapping` repeatedly, and will map `A` to `C` in this situation. ## Cons - The semantics are changed; `new_parents` now panics if `self.parent_mapping` contain cycles. AFAICT, such cycles never happen in `jj` anyway, except for one test that I had to fix. I think it's a sensible restriction to live with; if you do want to swap children of two commits, you can call `rebase_descendants` twice. ## Pros - I find the new logic much easier to reason about. I plan to extract it into a function, to be used in refactors for `jj rebase -r` and `jj new --after`. It will make it much easier to have a correct implementation of `jj rebase -r --after`, even when rebasing onto a descendant. - The de-duplication is no longer O(n^2). I tried to keep the common case fast. ## Alternatives - We could make `jj rebase` and `jj new` use a separate function with the algorithm shown here, without changing DescendantRebaser. I believe that the new algorithm makes DescendatRebaser easier to understand, though, and it feels more elegant to reduce code duplication. - The de-duplication optimization here is independent of other changes, and could be used on its own. |
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| benches | ||
| gen-protos | ||
| src | ||
| tests | ||
| testutils | ||
| Cargo.toml | ||
| LICENSE | ||