Improve exploit fix (#8)

font_api/fontform.lua

@@ -54,13 +54,7 @@ local function show_node_formspec(playername, pos)
 	fs = fs:gsub("context", nodemeta)
 
 	-- Change all ${} to their corresponding metadata values
-	fs = fs:gsub("(.)${(.-)}", function(prefix, key)
-		-- Don't alter escaped keys
-		if prefix == "\\" then
-			return prefix .. "${" .. key .. "}"
-		end
-
-		-- Get the node meta value
+	fs = fs:gsub("([^\\])${(.-)}", function(prefix, key)
 		return prefix .. minetest.formspec_escape(meta:get_string(key))
 	end)
 

signs_api/init.lua

@@ -28,11 +28,6 @@ local FS = function(...) return minetest.formspec_escape(S(...)) end
 
 function signs_api.set_display_text(pos, text, font)
 	local meta = minetest.get_meta(pos)
-	-- Horrible workaround to prevent the engine from trying to resolve
-	-- metadata keys
-	if text:sub(1, 2) == "${" and text:sub(-1) == "}" then
-		text = text .. " "
-	end
 	meta:set_string("display_text", text)
 	if text and text ~= "" then
 		meta:set_string("infotext", "\""..text.."\"")