[Question] Turn an interdiff into a change

[Doran-Penner]

Say my coworker pushes change A followed by a modified version B. I can use the evolog to see the diff from A to B, but what if I (or my coworker) want to turn that diff into a second change on top of A? You can manually jj split -r B and then select everything that's in A, but I'm wondering if there's some way to automatically do this (e.g. jj split -r B -base=A or whatever). Could also try piping a diff into a patch file or something for git, but maybe there's a better way? Thank you for any suggestions!

[jennings]

There might be a better way, but if A and B have the same parent, then this would work:

$ jj new A
$ jj restore --from B

If B's parent was rewritten, this might not be exactly right.

[Doran-Penner]

This is great, thank you! In the more general case, I found you can

$ jj new A
$ jj diff --from A --to B --git | git apply -

if parents were rewritten. (Or maybe interdiff?) Now I'm thinking about making a jj patch command (jj apply?) to emulate git apply... but that's a separate concern. In any case thanks 🙂