Re: [PATCH] git-submodule: fix expansion of depth for cmd_update

[Junio C Hamano <gitster@pobox.com>]

Jacob Keller <jacob.e.keller@intel.com> writes:

> From: Jacob Keller <jacob.keller@gmail.com>
>
> The depth variable already contains "--depth=", so expanding it with an
> additional --depth when invoking the update-clone git submodule--helper
> is incorrect.
>
> Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
> ---
>
> I'm *reasonably* sure this is correct, but I am not sure how to test it.
> It's possible that it expands to "--depth --depth=N" and somehow this gets
> handled properly?

I agree with your eyeballing of all the assignments to the variable,
and other references to $depth take either one of these two forms:

	git submodule--helper ... ${depth:+"$depth"} ...
	git submodule--helper ... $depth ...

As long as "git submodule ... --depth <depth> ..." gets called with
<depth> that does not have $IFS, either would work fine, but the
former is correct even when <depth> has problematic characters in it
and your patch uses that form, too).

However.

The command line parser for update_clone() stuffs --depth as a
string to suc.depth, and then the machinery ends up calling 
prepare_to_clone_next_submodule() with such an instance of suc
(struct submodule_update_clone).  Then that function just pushes the
suc->depth to an argv array used to spawn a "submodule--helper clone".

So passing "--depth --depth=23" would be "correct", sadly, in that
codepath (I am not saying other codepaths would not call the same
prepare_to_clone_next_submodule() with "--depth 23", as I didn't
check, and if there is such a codepath, it would break).  

We may need to clean the mess up X-<.

> diff --git a/git-submodule.sh b/git-submodule.sh
> index c7f58c5756f7..4e7fc8bf3652 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -547,7 +547,7 @@ cmd_update()
>  		${update:+--update "$update"} \
>  		${reference:+"$reference"} \
>  		${dissociate:+"--dissociate"} \
> -		${depth:+--depth "$depth"} \
> +		${depth:+"$depth"} \
>  		$recommend_shallow \
>  		$jobs \
>  		-- \