More tests, fixed patcher error handler

core/src/mindustry/world/meta/Attribute.java

@@ -1,6 +1,7 @@
 package mindustry.world.meta;
 
 import arc.struct.*;
+import arc.util.*;
 import mindustry.*;
 
 public class Attribute{
@@ -47,6 +48,11 @@ public class Attribute{
         return map.getThrow(name, () -> new IllegalArgumentException("Unknown Attribute type: " + name));
     }
 
+    /** May return null. */
+    public static @Nullable Attribute getOrNull(String name){
+        return map.get(name);
+    }
+
     /** @return Whether an attribute exists. */
     public static boolean exists(String name){
         return map.containsKey(name);