Paper/nms-patches/CraftingManager.patch

--- a/net/minecraft/server/CraftingManager.java
+++ b/net/minecraft/server/CraftingManager.java
@@ -22,11 +22,13 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap; // CraftBukkit
+
 public class CraftingManager extends ResourceDataJson {
 
     private static final Gson a = (new GsonBuilder()).setPrettyPrinting().disableHtmlEscaping().create();
     private static final Logger LOGGER = LogManager.getLogger();
-    public Map<Recipes<?>, Map<MinecraftKey, IRecipe<?>>> recipes = ImmutableMap.of();
+    public Map<Recipes<?>, Object2ObjectLinkedOpenHashMap<MinecraftKey, IRecipe<?>>> recipes = ImmutableMap.of(); // CraftBukkit
     private boolean d;
 
     public CraftingManager() {
@@ -35,7 +37,7 @@
 
     protected void a(Map<MinecraftKey, JsonObject> map, IResourceManager iresourcemanager, GameProfilerFiller gameprofilerfiller) {
         this.d = false;
-        Map<Recipes<?>, Builder<MinecraftKey, IRecipe<?>>> map1 = Maps.newHashMap();
+        Map<Recipes<?>, Object2ObjectLinkedOpenHashMap<MinecraftKey, IRecipe<?>>> map1 = Maps.newHashMap(); // CraftBukkit
         Iterator iterator = map.entrySet().iterator();
 
         while (iterator.hasNext()) {
@@ -45,24 +47,42 @@
             try {
                 IRecipe<?> irecipe = a(minecraftkey, (JsonObject) entry.getValue());
 
-                ((Builder) map1.computeIfAbsent(irecipe.g(), (recipes) -> {
-                    return ImmutableMap.builder();
-                })).put(minecraftkey, irecipe);
+                // CraftBukkit start - SPIGOT-4638: last recipe gets priority
+                (map1.computeIfAbsent(irecipe.g(), (recipes) -> {
+                    return new Object2ObjectLinkedOpenHashMap<>();
+                })).putAndMoveToFirst(minecraftkey, irecipe);
+                // CraftBukkit end
             } catch (IllegalArgumentException | JsonParseException jsonparseexception) {
                 CraftingManager.LOGGER.error("Parsing error loading recipe {}", minecraftkey, jsonparseexception);
             }
         }
 
         this.recipes = (Map) map1.entrySet().stream().collect(ImmutableMap.toImmutableMap(Entry::getKey, (entry1) -> {
-            return ((Builder) entry1.getValue()).build();
+            return (entry1.getValue()); // CraftBukkit
         }));
         CraftingManager.LOGGER.info("Loaded {} recipes", map1.size());
     }
 
+    // CraftBukkit start
+    public void addRecipe(IRecipe<?> irecipe) {
+        Object2ObjectLinkedOpenHashMap<MinecraftKey, IRecipe<?>> map = this.recipes.get(irecipe.g()); // CraftBukkit
+
+        if (map.containsKey(irecipe.getKey())) {
+            throw new IllegalStateException("Duplicate recipe ignored with ID " + irecipe.getKey());
+        } else {
+            map.putAndMoveToFirst(irecipe.getKey(), irecipe); // CraftBukkit - SPIGOT-4638: last recipe gets priority
+        }
+    }
+    // CraftBukkit end
+
     public <C extends IInventory, T extends IRecipe<C>> Optional<T> craft(Recipes<T> recipes, C c0, World world) {
-        return this.a(recipes).values().stream().flatMap((irecipe) -> {
+        // CraftBukkit start
+        Optional<T> recipe = this.a(recipes).values().stream().flatMap((irecipe) -> {
             return SystemUtils.a(recipes.a(irecipe, world, c0));
         }).findFirst();
+        c0.setCurrentRecipe(recipe.orElse(null)); // CraftBukkit - Clear recipe when no recipe is found
+        // CraftBukkit end
+        return recipe;
     }
 
     public <C extends IInventory, T extends IRecipe<C>> List<T> b(Recipes<T> recipes, C c0, World world) {
@@ -74,7 +94,7 @@
     }
 
     private <C extends IInventory, T extends IRecipe<C>> Map<MinecraftKey, IRecipe<C>> a(Recipes<T> recipes) {
-        return (Map) this.recipes.getOrDefault(recipes, Collections.emptyMap());
+        return (Map) this.recipes.getOrDefault(recipes, new Object2ObjectLinkedOpenHashMap<>()); // CraftBukkit
     }
 
     public <C extends IInventory, T extends IRecipe<C>> NonNullList<ItemStack> c(Recipes<T> recipes, C c0, World world) {
@@ -95,7 +115,7 @@
 
     public Optional<? extends IRecipe<?>> a(MinecraftKey minecraftkey) {
         return this.recipes.values().stream().map((map) -> {
-            return (IRecipe) map.get(minecraftkey);
+            return map.get(minecraftkey); // CraftBukkit - decompile error
         }).filter(Objects::nonNull).findFirst();
     }
 
@@ -118,4 +138,14 @@
             return new JsonSyntaxException("Invalid or unsupported recipe type '" + s + "'");
         })).a(minecraftkey, jsonobject);
     }
+
+    // CraftBukkit start
+    public void clearRecipes() {
+        this.recipes = Maps.newHashMap();
+
+        for (Recipes<?> recipeType : IRegistry.RECIPE_TYPE) {
+            this.recipes.put(recipeType, new Object2ObjectLinkedOpenHashMap<>());
+        }
+    }
+    // CraftBukkit end
 }