SPIGOT-3257: Issue with AdvancementRewards function

nms-patches/AdvancementRewards.patch

@@ -0,0 +1,20 @@
+--- a/net/minecraft/server/AdvancementRewards.java
++++ b/net/minecraft/server/AdvancementRewards.java
+@@ -98,7 +98,7 @@
+                 }
+ 
+                 public boolean getSendCommandFeedback() {
+-                    return minecraftserver.worldServer[0].getGameRules().getBoolean("commandBlockOutput");
++                    return minecraftserver.worlds.get(0).getGameRules().getBoolean("commandBlockOutput"); // CraftBukkit
+                 }
+ 
+                 public void a(CommandObjectiveExecutor.EnumCommandResult commandobjectiveexecutor_enumcommandresult, int i) {
+@@ -156,7 +156,7 @@
+             return new AdvancementRewards(i, aminecraftkey, aminecraftkey1, customfunction_a);
+         }
+ 
+-        public Object deserialize(JsonElement jsonelement, Type type, JsonDeserializationContext jsondeserializationcontext) throws JsonParseException {
++        public AdvancementRewards deserialize(JsonElement jsonelement, Type type, JsonDeserializationContext jsondeserializationcontext) throws JsonParseException { // CraftBukkit - decompile error
+             return this.a(jsonelement, type, jsondeserializationcontext);
+         }
+     }