Yes this is how jj does it, except that jj is more powerful because it does automatic rebase of all the downstream commits.
If you have any descendants of the gir history split (i.e. it's not the most recent) you'll have to do some more work (a rebase) to get back to a useful history. I think you can do this in the middle of an interactive rebase which is ok, but still not as easy.
If you have any descendants of the gir history split (i.e. it's not the most recent) you'll have to do some more work (a rebase) to get back to a useful history. I think you can do this in the middle of an interactive rebase which is ok, but still not as easy.