/** rename ref, return 0 on success **/
extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
-extern int create_symref(const char *ref, const char *refs_heads_master, const char *logmsg);
+extern int create_symref(const char *refname, const char *target, const char *logmsg);
+
+/*
+ * Update HEAD of the specified gitdir.
+ * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but
+ * this can update the main working tree's HEAD regardless of where
+ * $GIT_DIR points to.
+ * Return 0 if successful, non-zero otherwise.
+ * */
+extern int set_worktree_head_symref(const char *gitdir, const char *target);
enum action_on_err {
UPDATE_REFS_MSG_ON_ERR,