Builtin: Disallow registering users with the same name

Prevents duplicate names: 'NickName', 'nickname', 'NICKNAME'.
Skips already registered users, so they can connect as usual.

diff --git a/builtin/game/auth.lua b/builtin/game/auth.lua
index deb811b1448133077e8af1e61020053ec3fcbf03..46fe3d342778c50e15dac1d681ac7929a543a45d 100644 (file)
--- a/builtin/game/auth.lua
+++ b/builtin/game/auth.lua
@@ -199,3 +199,19 @@ core.register_on_joinplayer(function(player)
        record_login(player:get_player_name())
 end)
 
+core.register_on_prejoinplayer(function(name, ip)
+       local auth = core.auth_table
+       if auth[name] ~= nil then
+               return
+       end
+
+       local name_lower = name:lower()
+       for k in pairs(auth) do
+               if k:lower() == name_lower then
+                       return string.format("\nCannot create new player called '%s'. "..
+                                       "Another account called '%s' is already registered. "..
+                                       "Please check the spelling if it's your account "..
+                                       "or use a different nickname.", name, k)
+               end
+       end
+end)