Re: [PATCH 5/8] rebase: preserve interactive todo file on checkout failure

[Oswald Buddenhagen <oswald.buddenhagen@gmx.de>]

On Thu, Mar 23, 2023 at 01:16:47PM -0700, Junio C Hamano wrote:
>Oswald Buddenhagen <oswald.buddenhagen@gmx.de> writes:
>
>> Creating a suitable todo file is a potentially labor-intensive process,
>> so be less cavalier about discarding it when something goes wrong (e.g.,
>> the user messed with the repo while editing the todo).
>
>Is there a reason why we do not always keep it?  Why is the file
>sometimes precious but not precious at all in other times?
>
the unedited initial todo just isn't precious. that implies that in a 
non-interactive rebase, it is always worthless at the time of the 
initial reset.

>Tying the previous bit to "-i was explicitly given" feels a bit
>unintuitive---when the sequencer machinery was implicitly chosen,
>and gives the control back to the user, should a user be forbidden
>to muck with the todo list?
>
that would be an --edit-todo and --continue during a mid-rebase stop.  
rather different case.

>No // comments, please.
>
(apparently with a special exception for examples in the apidocs, 
presumably because escaping nested comments would be just too ugly.)

>> -	test_path_is_missing .git/rebase-merge &&
>> +	test_path_is_dir .git/rebase-merge &&
>
>Are we happy to just see that the directory still exists?  I thought
>the original motivation explained in the proposed log message was to
>keep the todo list file, so shouldn't you be checking if the file is
>there
>
fair point.

>(and if you can reliably ensure that the file has contents
>that are expected, that would be even better)?
>
i could grep for a shortened sha1 i would obtain from the branch. but 
given that the error scenario of a present but somehow corrupted todo 
seems implausible given the circumstances, that seems like overkill.

>Also, as the keeping of the todo list is now conditional, we should
>have another test that checks that the file is gone when that
>condition ("INTERACTIVE_EXPLICIT"?) does not trigger, I think.
>
that would be for t3400-rebase.sh.
i suppose we could extend 'Show verbose error when HEAD could not be 
detached'.