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

> -----Original Message-----
> From: git-owner@vger.kernel.org [mailto:git-owner@vger.kernel.org] On Behalf Of
> Junio C Hamano
> Sent: Thursday, August 22, 2019 2:01 PM
> To: Keller, Jacob E <jacob.e.keller@intel.com>
> Cc: git@vger.kernel.org; Jacob Keller <jacob.keller@gmail.com>
> Subject: Re: [PATCH] git-submodule: fix expansion of depth for cmd_update
> 
> 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).
> 

> > 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 \
> >  		-- \