Subject: Re: [PATCH v9 2/3] introduce submodule.hasSuperproject record

From: Emily Shaffer <[email-masked]>
Date: Tue, 15 Mar 2022 11:39:02 -0700

On Thu, Mar 10, 2022 at 02:10:55PM -0800, Junio C Hamano wrote:
> 
> Glen Choo <[email-masked]> writes:
> 
> > Junio C Hamano <[email-masked]> writes:
> >
> >> Emily Shaffer <[email-masked]> writes:
> >>
> >>> @@ -2617,6 +2622,12 @@ static int run_update_procedure(int argc, const char **argv, const char *prefix)
> >>>  
> >>>  	free(prefixed_path);
> >>>  
> >>> +	/*
> >>> +	 * This entry point is always called from a submodule, so this is a
> >>> +	 * good place to set a hint that this repo is a submodule.
> >>> +	 */
> >>> +	git_config_set("submodule.hasSuperproject", "true");
> >>> +
> >>>  	if (!oideq(&update_data.oid, &update_data.suboid) || update_data.force)
> >>>  		return do_run_update_procedure(&update_data);
> >>
> >> In Glen's update to rewrite "submodule update" in C, this part is
> >> replaced with a call to update_submodule2().  I am not sure what the
> >> current repository is at this point of the code with and without
> >> Glen's topic, but are we sure we are in a submodule we discovered?
> >
> > Rereading this, I realize you probably meant that this conflicts with
> > part1, not part2...
> >
> > At the end of part1, update_submodule2() is called from inside the
> > submodule (specifically from run_update_procedure()). So a good merge
> > conflict resolution would be to set the config _before_ calling
> > update_submodule2(). e.g.
> >
> > ----- >8 --------- >8 --------- >8 --------- >8 --------- >8 ----
> > diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> > index bef9ab22d4..f53808d995 100644
> > --- a/builtin/submodule--helper.c
> > +++ b/builtin/submodule--helper.c
> > @@ -2672,6 +2677,11 @@ static int run_update_procedure(int argc, const char **argv, const char *prefix)
> >                                             &update_data.update_strategy);
> >
> >         free(prefixed_path);
> > +       /*
> > +        * This entry point is always called from a submodule, so this is a
> > +        * good place to set a hint that this repo is a submodule.
> > +        */
> > +       git_config_set("submodule.hasSuperproject", "true");
> >         return update_submodule2(&update_data);
> >  }
> 
> That matched my tentative resolution I made last night, but what do
> you think about this part of the test added by the patch?
> 
> diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
> index 11cccbb333..ec2397fc69 100755
> --- a/t/t7406-submodule-update.sh
> +++ b/t/t7406-submodule-update.sh
> @@ -1061,4 +1061,12 @@ test_expect_success 'submodule update --quiet passes quietness to fetch with a s
>  	)
>  '
>  
> +test_expect_success 'submodule update adds submodule.hasSuperproject to older repos' '
> +	(cd super &&
> +	 test_unconfig submodule.hasSuperproject &&
> +	 git submodule update &&
> +	 test_cmp_config -C submodule true --type=bool submodule.hasSuperproject
> +	)
> +'
> +
>  test_done
> 
> We go to "super", make sure that superproject does not have
> submodule.hasSuperproject set, run "git submodule update", and see
> if the configuration file in "submodule" subdirectory has the
> variable set.  It does not clear the variable from the submodule
> before starting, so the variable given to the submodule when it was
> cloned would be there, even if "git submodule update" failed to set
> it.
> 
> I am wondering if it should do something like the attached instead.
> 
> We
> 
>  * clear the variable from "super" and "super/submodule"
>    repositories;
> 
>  * run "git submodule update";
> 
>  * ensure that "git submodule update" did not touch "super/.git/config";

Yeah, this is a good idea, and indeed when I add this step the bug
pointed out downthread becomes clear. Thanks.

> 
>  * ensure that "git submodule update" added the variable to
>    "super/submodule/.git/config".
> 
> Clearing the variable from "super" is technically wrong because the
> repository is set up as a submodule of "recursivesuper" and if we
> had further tests, we should restore it in "super", but the point is
> that we are makng sure "git submodule update" sets the variable in
> the configuration file of the submodule, and not in the superproject's. 
> 
> With the conflict resolution above, this "corrected" test fails and
> shows that superproject's configuration file is updated after "git
> submodule update".
> 
> This series alone, without your topic, this "corrected" test fails,
> and that is where my "are we sure we are mucking with the
> configuration file in the submodule"? comes from.
> 
> diff --git c/t/t7406-submodule-update.sh w/t/t7406-submodule-update.sh
> index 000e055811..c9912bb242 100755
> --- c/t/t7406-submodule-update.sh
> +++ w/t/t7406-submodule-update.sh
> @@ -1083,4 +1083,16 @@ test_expect_success 'submodule update --filter sets partial clone settings' '
>  	test_cmp_config -C super-filter/submodule blob:none remote.origin.partialclonefilter
>  '
>  
> +test_expect_success 'submodule update adds submodule.hasSuperproject to older repos' '
> +	(cd super &&
> +	 test_unconfig submodule.hasSuperproject &&
> +	 test_unconfig -C submodule submodule.hasSuperproject &&
> +	 git submodule update &&
> +	 echo in super &&
> +	 test_cmp_config false --type=bool submodule.hasSuperproject &&
> +	 echo in submodule &&
> +	 test_cmp_config -C submodule true --type=bool submodule.hasSuperproject
> +	)
> +'
> +
>  test_done