[PATCH 13/13] submodule--helper update-clone: check for --filter and --init

[Glen Choo <chooglen@google.com>]

"git submodule update --filter" also requires the "--init" option. Teach
update-clone to do this usage check in C and remove the check from
git-submodule.sh.

In addition, change update-clone's usage string so that it teaches users
about "git submodule update" instead of "git submodule--helper
update-clone" (the string is copied from git-submodule.sh). This should
be more helpful to users since they don't invoke update-clone directly.

Signed-off-by: Glen Choo <chooglen@google.com>
---
Since we expect users to act upon the usage string, I've updated it to
reflect "git submodule update" [1] (since that's what users actually
invoke), but I feel a bit iffy about not being able to use
usage_with_options() (because the options and usage string are for
different commands).

This might indicate that this is work we should put off until the
conversion to C is mostly complete, but on the other hand, the usage
string is still more helpful than it used to be because we never
presented users with the options anyway.

[1] It's not immediately obvious which command we prefer to show - some
other commands use "git submodule--helper" and others use "git
submodule".

 builtin/submodule--helper.c | 20 +++++++++++++++++++-
 git-submodule.sh            |  5 -----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 0fc07d35ae..ea88f39fb4 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -2544,7 +2544,12 @@ static int update_clone(int argc, const char **argv, const char *prefix)
 	};
 
 	const char *const git_submodule_helper_usage[] = {
-		N_("git submodule--helper update-clone [--prefix=<path>] [<path>...]"),
+		N_("git submodule [--quiet] update"
+		"[--init [--filter=<filter-spec>]] [--remote]"
+		"[-N|--no-fetch] [-f|--force]"
+		"[--checkout|--merge|--rebase]"
+		"[--[no-]recommend-shallow] [--reference <repository>]"
+		"[--recursive] [--[no-]single-branch] [--] [<path>...]"),
 		NULL
 	};
 	suc.prefix = prefix;
@@ -2555,6 +2560,19 @@ static int update_clone(int argc, const char **argv, const char *prefix)
 	memset(&filter_options, 0, sizeof(filter_options));
 	argc = parse_options(argc, argv, prefix, module_update_clone_options,
 			     git_submodule_helper_usage, 0);
+
+	if (filter_options.choice && !suc.init) {
+		/*
+		 * NEEDSWORK: Don't use usage_with_options() because the
+		 * usage string is for "git submodule update", but the
+		 * options are for "git submodule--helper update-clone".
+		 *
+		 * This will no longer be an issue when "update-clone"
+		 * is replaced by "git submodule--helper update".
+		 */
+		usage(git_submodule_helper_usage[0]);
+	}
+
 	suc.filter_options = &filter_options;
 
 	if (update)
diff --git a/git-submodule.sh b/git-submodule.sh
index 51be7c7f7e..aa8bdfca9d 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -356,11 +356,6 @@ cmd_update()
 		shift
 	done
 
-	if test -n "$filter" && test "$init" != "1"
-	then
-		usage
-	fi
-
 	{
 	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper update-clone \
 		${GIT_QUIET:+--quiet} \
-- 
2.33.GIT