[Nitro Cao <jaycecao520@gmail.com>]

Hi Junio and thanks for your time! I'm a newbie, sorry for the last
reply :(

> While your change may skip the code that segfaults, wouldn't it also
> stop noticing a broken case where .peer_ref should have been set but
> didn't, even when --revision=<rev> parameter is not used in the
> command invocation?  IOW, it is better to segfault and draw attention
> by Git developers when a valid input is given by the end user and our
> code misbehaves (e.g., and fails to to set .peer_ref as it should).

I totally agree with you.


> Wouldn't the correct fix be more like the following?
>
> - split out parts from update_remote_refs() that are needed even in
>   option_rev mode into a separate helper function, and call that
>   from cmd_clone().
>
> - make the call to update_remote_refs() conditional---specifically,
>   we shouldn't be calling it when option_rev is in effect.

Do we have another fix to make a conditional call to `find_ref_by_name()`
when `option_rev` is in effect? Because from the doc of `--revision`,
"... and detach `HEAD` to_<rev>_. ...", that means we don't need to
know where the real HEAD points to?

> Also, isn't this something we can specify the expected behaviour in
> tests?  Not only we want to ensure that nothing segfaults, we would
> want to make sure that the resulting repository has no refs and HEAD
> is detached at the specified revision.

I'll add several tests to cover the bug after we make sure how to fix it.