checkout: Use submodule.*.ignore settings from .git/config and .gitmodules

For "git status" and the diff family the submodule.*.ignore settings from
.git/config and .gitmodules can be used to override the default set via
diff.ignoreSubmodules on a per-submodule basis. Let's do this consistently
and teach checkout to use these settings too.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -608,6 +608,10 @@ static int git_checkout_config(const char *var, const char *value, void *cb)
 		handle_ignore_submodules_arg(&opts->diff_options, value);
 		return 0;
 	}
+
+	if (!prefixcmp(var, "submodule."))
+		return parse_submodule_config_option(var, value);
+
 	return git_xmerge_config(var, value, NULL);
 }
 
@@ -689,6 +693,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	memset(&opts, 0, sizeof(opts));
 	memset(&new, 0, sizeof(new));
 
+	gitmodules_config();
 	git_config(git_checkout_config, &opts);
 
 	opts.track = BRANCH_TRACK_UNSPECIFIED;

t/t2013-checkout-submodule.sh

@@ -46,4 +46,20 @@ test_expect_success '"checkout <submodule>" honors diff.ignoreSubmodules' '
 	! test -s actual
 '
 
+test_expect_success '"checkout <submodule>" honors submodule.*.ignore from .gitmodules' '
+	git config diff.ignoreSubmodules none &&
+	git config -f .gitmodules submodule.submodule.path submodule &&
+	git config -f .gitmodules submodule.submodule.ignore untracked &&
+	git checkout HEAD >actual 2>&1 &&
+	! test -s actual
+'
+
+test_expect_success '"checkout <submodule>" honors submodule.*.ignore from .git/config' '
+	git config -f .gitmodules submodule.submodule.ignore none &&
+	git config submodule.submodule.path submodule &&
+	git config submodule.submodule.ignore all &&
+	git checkout HEAD >actual 2>&1 &&
+	! test -s actual
+'
+
 test_done