Re: [PATCH v3 4/4] submodule: port submodule subcommand 'summary' from shell to C

> On Fri, 2020-08-21 at 12:54 -0700, Junio C Hamano wrote:
> > Kaartic Sivaraam <kaartic.sivaraam@gmail.com> writes:
> > 
> > > So, we could easily suppress it by doing something like this (while
> > > also fixing the test):
> > 
> > Yup.  That is a very good idea.  
> > 
> > Or the caller of verify_submodule_committish() should refrain from
> > calling it for the path?  After all, it is checking sm_path is a
> > path to where a submodule should be before calling the function
> > (instead of calling it for every random path), iow its criteria to
> > make the call currently may be "the path in the index says it is a
> > submodule", but it should easily be updated to "the path in the
> > index says it is a submodule, and the submodule actually is
> > populated", right?
> > 
> 
> Ah, this reminds me of the initial version of the patch which did
> exactly that. Quoting it here for reference:
> 
> +	strbuf_addstr(&sm_git_dir_sb, p->sm_path);
> +	if (is_nonbare_repository_dir(&sm_git_dir_sb))
> +		is_sm_git_dir = 1;
> +
> +	if (is_sm_git_dir && S_ISGITLINK(p->mod_src))
> +		missing_src = verify_submodule_object_name(p->sm_path,
> +							   oid_to_hex(&p->oid_src));
> +
> +	if (is_sm_git_dir && S_ISGITLINK(p->mod_dst))
> +		missing_dst = verify_submodule_object_name(p->sm_path,
> +							   oid_to_hex(&p->oid_dst));
> +
> 
> Note: `verify_submodule_object_name` is now renamed to
> `verify_submodule_committish`.
> 
> That does sound like a sane approach to me. There's not much point in
> invoking `rev-parse` in a non-populated (a.k.a. de-initialized) or non-
> existent submodule but we removed that check as we thought it was
> unnecessary redundant because `capture_command` would fail anyway.
> Looks like we failed to notice the additional `fatal` message fallout
> then.
> 

> Also, I think it would be better to something like the following in
> t7421 to ensure that `fatal` doesn't sneak up accidentally in the
> future:
> 
> -- 8< --
> diff --git t/t7421-submodule-summary-add.sh t/t7421-submodule-summary-add.sh
> index 59a9b00467..b070f13714 100755
> --- t/t7421-submodule-summary-add.sh
> +++ t/t7421-submodule-summary-add.sh
> @@ -58,7 +58,7 @@ test_expect_success 'submodule summary output for submodules with changed paths'
>         git commit -m "change submodule path" &&
>         rev=$(git -C sm rev-parse --short HEAD^) &&
>         git submodule summary HEAD^^ -- my-subm >actual 2>err &&
> -       grep "fatal:.*my-subm" err &&
> +       test_must_be_empty err &&
>         cat >expected <<-EOF &&
>         * my-subm ${rev}...0000000:
>  
> -- >8 --
>