On Thu, Mar 16, 2023 at 4:46 PM Glen Choo [off-list ref] wrote:

Felipe Contreras [off-list ref] writes:

quoted

quoted

--[no-]rebase-merges [--rebase-merges-mode=(rebase-cousins|no-rebase-cousins)]

I don't think there would be any confusion.
[...]
(Having --rebase-merges-mode
be a no-op without --rebase-merges is probably even more confusing to
users, plus this would break backwards compatibility, so I don't think
this is a good idea at all.)

I don't find it confusing. And how would it break backwards
compatibility if --rebase-merges-mode doesn't exist now?

I meant that for the above example to work, we would need to have
`--[no-]rebase-merges` as a boolean that says whether we rebase merges at
all, and `--rebase-merges-mode=[whatever]` would tell us what mode to
use _if_ we were rebasing merges.

No, we don't need --no-rebase-merges for --rebase-merges-mode to work.
It would be nice, but not necessary.

This means that
`--rebase-merges=not-a-boolean` would become invalid.

No, it would not become invalid, that's yet another decision to make.
`--rebase-merges=mode` could become synonymous with `--rebase-merges
--rebase-merges-mode=mode`. A shortcut.

Because it's redundant it could be deprecated in the future, but not
necessarily invalid.

We were in this position before, actually, with `git log -p -m`. The
conclusion on a recent series [1] is that having such a no-op flag was
probably a mistake (and unfortunately, one that is extremely hard to fix
due to backwards compatibility requirements),

No, `git log -m` was a mistake *only* if -p isn't turned on as well,
which is an interface wart that could be fixed today.

so introducing more no-op flags is probably a bad idea :)

Whether --rebase-merges-mode turns on --rebase-merges by default is a
decision that could be made in the future. Just like `git log -m`
turning on `-p` by default is a decision that could be made in the
future (and probably should).

---

Either way: introducing a new option cannot possibly break backwards
compatibility.

Cheers.

-- 
Felipe Contreras