submodule--helper: move config-sanitizing to submodule.c

These functions should be used by any code which spawns a
submodule process, which may happen in submodule.c (e.g.,
for spawning fetch). Let's move them there and make them
public so that submodule--helper can continue to use them.

Since they're now public, let's also provide a basic overview
of their intended use.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/submodule.c b/submodule.c
index b83939c294..24e8182f59 100644
--- a/submodule.c
+++ b/submodule.c
@@ -13,6 +13,7 @@
 #include "argv-array.h"
 #include "blob.h"
 #include "thread-utils.h"
+#include "quote.h"
 
 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
 static struct string_list changed_submodule_paths;
@@ -1097,3 +1098,50 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
 	strbuf_release(&rel_path);
 	free((void *)real_work_tree);
 }
+/*
+ * 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;
+}
+
+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;
+}
+
+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);
+		}
+	}
+
+}