let's play the optimization game featuring lighting (#12310)

* debug proc

* kinda quirky

* let's play the lighting game

* let's play the macro game

* let's play the refactor game

* let's play the optimization game

* let's play the optimization game x2

* yeehaw

* e

* let's play the memory game

* fix

* lighting fix

* sanitization and checks

* mh

* hotkeys fix

* ok

code/modules/client/preferences_savefile.dm

@@ -317,8 +317,23 @@ SAVEFILE UPDATING/VERSIONING - 'Simplified', or rather, more coder-friendly ~Car
 	no_tetris_storage		= sanitize_integer(no_tetris_storage, 0, 1, initial(no_tetris_storage))
 	key_bindings 	= sanitize_islist(key_bindings, list())
 
+	verify_keybindings_valid()		// one of these days this will runtime and you'll be glad that i put it in a different proc so no one gets their saves wiped
+
 	return 1
 
+/datum/preferences/proc/verify_keybindings_valid()
+	// Sanitize the actual keybinds to make sure they exist.
+	for(var/key in key_bindings)
+		if(!islist(key_bindings[key]))
+			key_bindings -= key
+		var/list/binds = key_bindings[key]
+		for(var/bind in binds)
+			if(!GLOB.keybindings_by_name[bind])
+				binds -= bind
+		if(!length(binds))
+			key_bindings -= key
+	// End
+
 /datum/preferences/proc/save_preferences()
 	if(!path)
 		return 0