Re: [PATCH] checkout: add --autostash option for branch switching

>> Why is the dry-run of unpack_trees() not an extra check? I was assuming 
>> that it was because we do the dry-run and then do it for real after 
>> possibly stashing any local changes. That's why I was wondering if we 
>> could avoid the dry-run by creating the stash if the non-dry-run 
>> unpack_trees() failed.
>
> Ah, I didn't even think about that possibility.
>
> Try to unpack anyway, and if unpack_trees() branch switching
> succeeds, we are done.  Otherwise, we can trust that unpack_trees()
> did not do _anything_ to the index or the working tree files, so we
> can create the stash at that time.
>
> Makes sense.