Merge branch 'defense-in-depth'

This topic branch adds a couple of measures designed to make it much
harder to exploit any bugs in Git's recursive clone machinery that might
be found in the future.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

1 files changed, 55 insertions, 0 deletions

diff --git a/setup.c b/setup.c
index 9d401ae4c8..c3301f5ab8 100644
--- a/setup.c
+++ b/setup.c
@@ -6,6 +6,7 @@
 #include "chdir-notify.h"
 #include "promisor-remote.h"
 #include "quote.h"
+#include "exec-cmd.h"
 
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
@@ -1720,3 +1721,57 @@ int daemonize(void)
 	return 0;
 #endif
 }
+
+#ifndef DEFAULT_GIT_TEMPLATE_DIR
+#define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
+#endif
+
+struct template_dir_cb_data {
+	char *path;
+	int initialized;
+};
+
+static int template_dir_cb(const char *key, const char *value, void *d)
+{
+	struct template_dir_cb_data *data = d;
+
+	if (strcmp(key, "init.templatedir"))
+		return 0;
+
+	if (!value) {
+		data->path = NULL;
+	} else {
+		char *path = NULL;
+
+		FREE_AND_NULL(data->path);
+		if (!git_config_pathname((const char **)&path, key, value))
+			data->path = path ? path : xstrdup(value);
+	}
+
+	return 0;
+}
+
+const char *get_template_dir(const char *option_template)
+{
+	const char *template_dir = option_template;
+
+	if (!template_dir)
+		template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
+	if (!template_dir) {
+		static struct template_dir_cb_data data;
+
+		if (!data.initialized) {
+			git_protected_config(template_dir_cb, &data);
+			data.initialized = 1;
+		}
+		template_dir = data.path;
+	}
+	if (!template_dir) {
+		static char *dir;
+
+		if (!dir)
+			dir = system_path(DEFAULT_GIT_TEMPLATE_DIR);
+		template_dir = dir;
+	}
+	return template_dir;
+}