fpga: Make formspec usage less prone to breakage

mesecons_fpga/init.lua

@@ -142,7 +142,7 @@ plg.to_formspec_string = function(is)
 	local function dropdown_action(x, y, name, val)
 		local s = "dropdown[" .. tostring(x) .. "," .. tostring(y) .. ";"
 				.. "1.125,0.5;" .. name .. ";" -- the height seems to be ignored?
-		s = s .. " , AND, OR, NOT, XOR,NAND,   =,XNOR;"
+		s = s .. " , AND,  OR, NOT, XOR,NAND,   =,XNOR;"
 		if val == nil then
 			return s .. "0]" -- actually selects no field at all
 		end
@@ -203,14 +203,15 @@ plg.from_formspec_fields = function(fields)
 			return nil
 		end
 		local mapping = {
-			[" AND"] = "and",
-			["  OR"] = "or",
-			[" NOT"] = "not",
-			[" XOR"] = "xor",
+			["AND"] = "and",
+			["OR"] = "or",
+			["NOT"] = "not",
+			["XOR"] = "xor",
 			["NAND"] = "nand",
-			["   ="] = "buf",
+			["="] = "buf",
 			["XNOR"] = "xnor",
 		}
+		s = s:gsub("^%s*", "") -- remove leading spaces
 		return mapping[s]
 	end
 	local is = {}