[BUG] git config --unset is not idempotent

[BUG] git config --unset is not idempotent

[Arturo Seijas Fernandez]

The command "git config --unset [option]" is not idempotent. It is
currently returning a success  code when the property had already been
set and a 5 error code otherwise.

I would expect the error code to be set according to the current state
when compared to the target state, regardless of the previous state of
the option.

Thank you,

Arturo Seijas

Re: [BUG] git config --unset is not idempotent

[Jeff King]

On Thu, Aug 25, 2022 at 10:52:16AM +0200, Arturo Seijas Fernandez wrote:

> The command "git config --unset [option]" is not idempotent. It is
> currently returning a success  code when the property had already been
> set and a 5 error code otherwise.
> 
> I would expect the error code to be set according to the current state
> when compared to the target state, regardless of the previous state of
> the option.

You can get what you want in the shell with:

  # passes "set -e", but could also be used in an "if"
  git config --unset ... || test $? = 5

That's obviously not as convenient. The flip side is that returning 0
would make it very hard for callers to tell if they removed something
(if they care).

If we were designing the tool now, I could definitely see an argument
for returning 0 in this case. But we have over a decade with the "5"
exit code documented for a plumbing tool. We won't change it now without
a good reason and without a deprecation schedule, and IMHO this doesn't
rise to that level.

-Peff

Re: [BUG] git config --unset is not idempotent

[Junio C Hamano]

Arturo Seijas Fernandez <arturo.seijas@canonical.com> writes:

> The command "git config --unset [option]" is not idempotent. It is
> currently returning a success  code when the property had already been
> set and a 5 error code otherwise.

"rm" is not "idempotent", either.

    echo >file
    rm file ; echo $?
    rm file ; echo $?

The "git config --unset" command signals the inability to unset a
variable when the variable to be unset does not even exist.