Implements hash_name for anonymous surveys

internal.lua

@@ -30,6 +30,17 @@ end
 
 function yl_survey.priv_exists(priv) return priv_exists(priv) end
 
+-- Hash name
+
+local function hash_name(name)
+    if ((type(name) ~= "string") or (name = "")) then
+        return nil
+    end
+    return minetest.sha256(name, false)
+end
+
+function yl_survey.hash_name(name) return hash_name(name) end
+
 -- Load and save
 
 local function get_savepath()