1 files changed, 67 insertions, 1 deletions

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 35ae85a7e1..3d37c3f182 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -124,6 +124,55 @@ static int module_name(int argc, const char **argv, const char *prefix)
 
 	return 0;
 }
+
+/*
+ * Rules to sanitize configuration variables that are Ok to be passed into
+ * submodule operations from the parent project using "-c". Should only
+ * include keys which are both (a) safe and (b) necessary for proper
+ * operation.
+ */
+static int submodule_config_ok(const char *var)
+{
+	if (starts_with(var, "credential."))
+		return 1;
+	return 0;
+}
+
+static int sanitize_submodule_config(const char *var, const char *value, void *data)
+{
+	struct strbuf *out = data;
+
+	if (submodule_config_ok(var)) {
+		if (out->len)
+			strbuf_addch(out, ' ');
+
+		if (value)
+			sq_quotef(out, "%s=%s", var, value);
+		else
+			sq_quote_buf(out, var);
+	}
+
+	return 0;
+}
+
+static void prepare_submodule_repo_env(struct argv_array *out)
+{
+	const char * const *var;
+
+	for (var = local_repo_env; *var; var++) {
+		if (!strcmp(*var, CONFIG_DATA_ENVIRONMENT)) {
+			struct strbuf sanitized_config = STRBUF_INIT;
+			git_config_from_parameters(sanitize_submodule_config,
+						   &sanitized_config);
+			argv_array_pushf(out, "%s=%s", *var, sanitized_config.buf);
+			strbuf_release(&sanitized_config);
+		} else {
+			argv_array_push(out, *var);
+		}
+	}
+
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, const char *reference, int quiet)
 {
@@ -145,7 +194,7 @@ static int clone_submodule(const char *path, const char *gitdir, const char *url
 	argv_array_push(&cp.args, path);
 
 	cp.git_cmd = 1;
-	cp.env = local_repo_env;
+	prepare_submodule_repo_env(&cp.env_array);
 	cp.no_stdin = 1;
 
 	return run_command(&cp);
@@ -259,6 +308,22 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+static int module_sanitize_config(int argc, const char **argv, const char *prefix)
+{
+	struct strbuf sanitized_config = STRBUF_INIT;
+
+	if (argc > 1)
+		usage(_("git submodule--helper sanitize-config"));
+
+	git_config_from_parameters(sanitize_submodule_config, &sanitized_config);
+	if (sanitized_config.len)
+		printf("%s\n", sanitized_config.buf);
+
+	strbuf_release(&sanitized_config);
+
+	return 0;
+}
+
 struct cmd_struct {
 	const char *cmd;
 	int (*fn)(int, const char **, const char *);
@@ -268,6 +333,7 @@ static struct cmd_struct commands[] = {
 	{"list", module_list},
 	{"name", module_name},
 	{"clone", module_clone},
+	{"sanitize-config", module_sanitize_config},
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)