Fix ClientPickBlockApplyCallback.EVENT not working as expected Fixes #1493 (#1498)

Co-authored-by: Player <player@player.to>

fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/mixin/event/interaction/MixinMinecraftClient.java

@@ -105,7 +105,7 @@ public abstract class MixinMinecraftClient {
 	@Shadow
 	public abstract ItemStack addBlockEntityNbt(ItemStack itemStack_1, BlockEntity blockEntity_1);
 
-	@ModifyVariable(at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/player/PlayerInventory;getSlotWithStack(Lnet/minecraft/item/ItemStack;)I"), method = "doItemPick", ordinal = 0)
+	@ModifyVariable(at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/player/PlayerInventory;getSlotWithStack(Lnet/minecraft/item/ItemStack;)I", shift = At.Shift.BEFORE), method = "doItemPick", ordinal = 0)
 	public ItemStack modifyItemPick(ItemStack stack) {
 		MinecraftClient client = (MinecraftClient) (Object) this;
 		ItemStack result = ClientPickBlockApplyCallback.EVENT.invoker().pick(client.player, client.crosshairTarget, stack);

fabric-events-interaction-v0/src/testmod/java/net/fabricmc/fabric/test/event/interaction/PlayerPickBlockTests.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.test.event.interaction;
+
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.util.Hand;
+
+import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.client.player.ClientPickBlockApplyCallback;
+
+public class PlayerPickBlockTests implements ModInitializer {
+	@Override
+	public void onInitialize() {
+		ClientPickBlockApplyCallback.EVENT.register((player, result, stack) -> {
+			if (player.getStackInHand(Hand.MAIN_HAND).getItem() == Items.DIAMOND) {
+				return new ItemStack(Items.OBSIDIAN);
+			}
+
+			if (stack.getItem() == Items.GRASS_BLOCK) {
+				return ItemStack.EMPTY;
+			}
+
+			return stack;
+		});
+	}
+}

fabric-events-interaction-v0/src/testmod/resources/fabric.mod.json

@@ -10,7 +10,8 @@
   },
   "entrypoints": {
     "main": [
-      "net.fabricmc.fabric.test.event.interaction.PlayerBreakBlockTests"
+      "net.fabricmc.fabric.test.event.interaction.PlayerBreakBlockTests",
+      "net.fabricmc.fabric.test.event.interaction.PlayerPickBlockTests"
     ]
   }
 }