SPIGOT-7664: Item meta should prevail over block states

By: md_5 <git@md-5.net>

paper-server/nms-patches/net/minecraft/core/component/DataComponentPatch.patch

@@ -18,7 +18,7 @@
          }
      };
      private static final String REMOVED_PREFIX = "!";
-@@ -270,6 +270,38 @@
+@@ -270,6 +270,42 @@
  
          a() {}
  
@@ -31,6 +31,10 @@
 +            this.map.remove(type);
 +        }
 +
++        public boolean isSet(DataComponentType<?> type) {
++            return map.containsKey(type);
++        }
++
 +        public boolean isEmpty() {
 +            return this.map.isEmpty();
 +        }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java

@@ -212,7 +212,7 @@ public class CraftMetaBlockState extends CraftMetaItem implements BlockStateMeta
             tag.put(BLOCK_ENTITY_TAG, CustomData.of(blockEntityTag.getSnapshotNBTWithoutComponents()));
 
             for (TypedDataComponent<?> component : blockEntityTag.collectComponents()) {
-                tag.builder.set(component);
+                tag.putIfAbsent(component);
             }
         }
     }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java

@@ -45,6 +45,7 @@ import net.minecraft.core.IRegistryCustom;
 import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.core.component.DataComponentType;
 import net.minecraft.core.component.DataComponents;
+import net.minecraft.core.component.TypedDataComponent;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.nbt.DynamicOpsNBT;
 import net.minecraft.nbt.NBTBase;
@@ -173,13 +174,20 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
     static final class Applicator {
 
-        final DataComponentPatch.a builder = DataComponentPatch.builder();
+        private final DataComponentPatch.a builder = DataComponentPatch.builder();
 
         <T> Applicator put(ItemMetaKeyType<T> key, T value) {
             builder.set(key.TYPE, value);
             return this;
         }
 
+        <T> Applicator putIfAbsent(TypedDataComponent<?> component) {
+            if (!builder.isSet(component.type())) {
+                builder.set(component);
+            }
+            return this;
+        }
+
         DataComponentPatch build() {
             return builder.build();
         }