From efa825c9d79e472aa24e50ead8dd87dca1b8b3fc Mon Sep 17 00:00:00 2001
From: Bruno Ploumhans <13494793+Technici4n@users.noreply.github.com>
Date: Tue, 24 Dec 2024 14:23:34 +0100
Subject: [PATCH] Fix NPE in WaterPotionStorage#isWaterPotion (#4313)

* Fix NPE in WaterPotionStorage#isWaterPotion

* Make checkstyle happy
---
 .../fabric/impl/transfer/fluid/WaterPotionStorage.java | 10 +++-------
 .../fabric/test/transfer/unittests/FluidItemTests.java |  8 ++++++++
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/fabric-transfer-api-v1/src/main/java/net/fabricmc/fabric/impl/transfer/fluid/WaterPotionStorage.java b/fabric-transfer-api-v1/src/main/java/net/fabricmc/fabric/impl/transfer/fluid/WaterPotionStorage.java
index 922abf68e4..de790a8344 100644
--- a/fabric-transfer-api-v1/src/main/java/net/fabricmc/fabric/impl/transfer/fluid/WaterPotionStorage.java
+++ b/fabric-transfer-api-v1/src/main/java/net/fabricmc/fabric/impl/transfer/fluid/WaterPotionStorage.java
@@ -16,8 +16,6 @@
 
 package net.fabricmc.fabric.impl.transfer.fluid;
 
-import java.util.Optional;
-
 import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.component.DataComponentTypes;
@@ -25,9 +23,7 @@
 import net.minecraft.fluid.Fluids;
 import net.minecraft.item.ItemStack;
 import net.minecraft.item.Items;
-import net.minecraft.potion.Potion;
 import net.minecraft.potion.Potions;
-import net.minecraft.registry.entry.RegistryEntry;
 
 import net.fabricmc.fabric.api.transfer.v1.context.ContainerItemContext;
 import net.fabricmc.fabric.api.transfer.v1.fluid.FluidConstants;
@@ -52,9 +48,9 @@ public static WaterPotionStorage find(ContainerItemContext context) {
 
 	private static boolean isWaterPotion(ContainerItemContext context) {
 		ItemVariant variant = context.getItemVariant();
-		Optional<? extends PotionContentsComponent> potionContents = variant.getComponents().get(DataComponentTypes.POTION_CONTENTS);
-		RegistryEntry<Potion> potion = potionContents.map(PotionContentsComponent::potion).orElse(null).orElse(null);
-		return variant.isOf(Items.POTION) && potion == Potions.WATER;
+		PotionContentsComponent potionContents = variant.getComponentMap()
+				.getOrDefault(DataComponentTypes.POTION_CONTENTS, PotionContentsComponent.DEFAULT);
+		return variant.isOf(Items.POTION) && potionContents.potion().orElse(null) == Potions.WATER;
 	}
 
 	private final ContainerItemContext context;
diff --git a/fabric-transfer-api-v1/src/test/java/net/fabricmc/fabric/test/transfer/unittests/FluidItemTests.java b/fabric-transfer-api-v1/src/test/java/net/fabricmc/fabric/test/transfer/unittests/FluidItemTests.java
index 16d7c2fc0a..8b0fdb98f2 100644
--- a/fabric-transfer-api-v1/src/test/java/net/fabricmc/fabric/test/transfer/unittests/FluidItemTests.java
+++ b/fabric-transfer-api-v1/src/test/java/net/fabricmc/fabric/test/transfer/unittests/FluidItemTests.java
@@ -173,6 +173,14 @@ public void testWaterPotion() {
 		if (StorageUtil.findStoredResource(luckyStorage) != null) {
 			throw new AssertionError("Found a resource in an unhandled potion.");
 		}
+
+		// Make sure extraction returns nothing for no potion at all
+		testInventory.setStack(0, new ItemStack(Items.POTION));
+		Storage<FluidVariant> defaultStorage = new InventoryContainerItem(testInventory, 0).find(FluidStorage.ITEM);
+
+		if (StorageUtil.findStoredResource(defaultStorage) != null) {
+			throw new AssertionError("Found a resource in empty potion.");
+		}
 	}
 
 	@Test