Fix malformed client ready packet crashing server

mods/MISC/mcl_engine_workarounds/init.lua

@@ -204,3 +204,26 @@ local test_minetest_find_nodes_in_area_implementation_equivalence = function()
 end
 
 minetest.after( 0, test_minetest_find_nodes_in_area_implementation_equivalence )
+
+--Workaround for Minetest bug #12073
+-- <https://github.com/minetest/minetest/issues/12073#issuecomment-1039389509>
+minetest.register_on_joinplayer(function(p)
+	p:get_meta():set_string("joined","true")
+end)
+minetest.register_on_leaveplayer(function(p)
+	p:get_meta():set_string("joined","")
+end)
+
+local function is_real_player(p)
+	if p:get_meta():get("joined") then return true end
+end
+
+local mgcp = minetest.get_connected_players
+
+function minetest.get_connected_players()
+	local pp={}
+	for k,p in pairs(mgcp()) do
+		if is_real_player(p) then table.insert(pp,p) end
+	end
+	return pp
+end