[PATCH v6 2/7] submodule: don't pass empty string arguments to submodule--helper clone

[Jacob Keller <jacob.e.keller@intel.com>]

From: Jacob Keller <jacob.keller@gmail.com>

When --reference or --depth are unused, the current git-submodule.sh
results in empty "" arguments appended to the end of the argv array
inside git submodule--helper clone. This is not caught because the argc
count is not checked today.

Fix git-submodule.sh to only pass an argument when --reference or
--depth are used, preventing the addition of two empty string arguments
on the tail of the argv array.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
---
This is a split of a previous patch as suggested by Junio, to make it
easier to review the changes.

 git-submodule.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 9bc5c5f94d1d..2dd29b3df0e6 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -347,7 +347,7 @@ Use -f if you really want to add it." >&2
 				echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
 			fi
 		fi
-		git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" "$reference" "$depth" || exit
+		git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" ${reference:+"$reference"} ${depth:+"$depth"} || exit
 		(
 			clear_local_git_env
 			cd "$sm_path" &&
@@ -709,7 +709,7 @@ Maybe you want to use 'update --init'?")"
 
 		if ! test -d "$sm_path"/.git && ! test -f "$sm_path"/.git
 		then
-			git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$prefix" --path "$sm_path" --name "$name" --url "$url" "$reference" "$depth" || exit
+			git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$prefix" --path "$sm_path" --name "$name" --url "$url" ${reference:+"$reference"} ${depth:+"$depth"} || exit
 			cloned_modules="$cloned_modules;$name"
 			subsha1=
 		else
-- 
2.7.1.429.g45cd78e