Auth Patch for Minetest 0.4.14
https://forum.minetest.net/viewtopic.php?f=6&t=16656
------------------------------------

This patch resolves a critical bug in the builtin authentication handler of Minetest 0.4.14 which can potentially hang the server 
thread during excessive I/O operations to auth.txt. The lag spikes are particularly noticeable on high-traffic servers with tens 
of thousands of registered users.

As a workaround, all writing and reading of auth.txt is disabled until startup and shutdown via a new auth.commit( ) function or 
upon operator request using an "auth_commit" chat command.

Simply copy the files from this archive into the "builtin/game" subdirectory, then restart the Minetest server. The changes will 
take affect immediately.

NB: If you are deploying this patch for Minetest 0.4.15, then you will need to manually update chatcommands.lua, rather than 
overwriting the entire file.

core.register_chatcommand("auth_reload", {
        params = "",
        description = "read authentication data from disk",
        privs = {server=true},
        func = function(name, param)
                local done = core.auth_reload()
                return done, (done and "Authentication data successfully loaded from disk." or "Failed to read the auth.txt file.")
        end,
})

core.register_chatcommand("auth_commit", {
        params = "",
        description = "write authentication data to disk",
        privs = {server=true},
        func = function(name, param)
                local done = core.auth_commit()
                return done, (done and "Authentication data successfully saved to disk." or "Failed to write the auth.txt file.")
        end,
})

~SorceryKid
