From dff459a75f3ce7926d187e80e3c9d3bde63990fa Mon Sep 17 00:00:00 2001
From: reidbhuntley <reidbhuntley@gmail.com>
Date: Sat, 5 Jun 2021 00:08:24 -0400
Subject: [PATCH] Fix bad behavior with small-max-stack-sized items when
 extracting multiple items at once

---
 .../create/foundation/item/ItemHelper.java    | 15 ++++++++-----
 .../inventory/InvManipulationBehaviour.java   | 21 ++++++++++++-------
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/main/java/com/simibubi/create/foundation/item/ItemHelper.java b/src/main/java/com/simibubi/create/foundation/item/ItemHelper.java
index e8a901d58..2121a6a71 100644
--- a/src/main/java/com/simibubi/create/foundation/item/ItemHelper.java
+++ b/src/main/java/com/simibubi/create/foundation/item/ItemHelper.java
@@ -7,6 +7,8 @@ import java.util.function.Predicate;
 
 import javax.annotation.Nullable;
 
+import net.minecraft.item.Item;
+
 import org.apache.commons.lang3.mutable.MutableInt;
 
 import com.simibubi.create.foundation.config.AllConfigs;
@@ -161,7 +163,7 @@ public class ItemHelper {
 					continue;
 				if (!test.test(stack))
 					continue;
-				if (!extracting.isEmpty() && !ItemHandlerHelper.canItemStacksStack(stack, extracting)) {
+				if (!extracting.isEmpty() && !canItemStackAmountsStack(stack, extracting)) {
 					potentialOtherMatch = true;
 					continue;
 				}
@@ -174,8 +176,7 @@ public class ItemHelper {
 				if (!simulate && hasEnoughItems)
 					inv.extractItem(slot, stack.getCount(), false);
 
-				if (extracting.getCount() >= maxExtractionCount
-					|| extracting.getCount() >= extracting.getMaxStackSize()) {
+				if (extracting.getCount() >= maxExtractionCount) {
 					if (checkHasEnoughItems) {
 						hasEnoughItems = true;
 						checkHasEnoughItems = false;
@@ -225,7 +226,7 @@ public class ItemHelper {
 
 			if (!test.test(stack))
 				continue;
-			if (!extracting.isEmpty() && !ItemHandlerHelper.canItemStacksStack(stack, extracting))
+			if (!extracting.isEmpty() && !canItemStackAmountsStack(stack, extracting))
 				continue;
 
 			if (extracting.isEmpty())
@@ -235,13 +236,17 @@ public class ItemHelper {
 
 			if (!simulate)
 				inv.extractItem(slot, stack.getCount(), false);
-			if (extracting.getCount() >= maxExtractionCount || extracting.getCount() >= extracting.getMaxStackSize())
+			if (extracting.getCount() >= maxExtractionCount)
 				break;
 		}
 
 		return extracting;
 	}
 
+	public static boolean canItemStackAmountsStack(ItemStack a, ItemStack b) {
+		return ItemHandlerHelper.canItemStacksStack(a,b) && a.getCount() + b.getCount() <= a.getMaxStackSize();
+	}
+
 	public static ItemStack findFirstMatch(IItemHandler inv, Predicate<ItemStack> test) {
 		int slot = findFirstMatchingSlotIndex(inv, test);
 		if (slot == -1)
diff --git a/src/main/java/com/simibubi/create/foundation/tileEntity/behaviour/inventory/InvManipulationBehaviour.java b/src/main/java/com/simibubi/create/foundation/tileEntity/behaviour/inventory/InvManipulationBehaviour.java
index eac304882..ba96a9fc2 100644
--- a/src/main/java/com/simibubi/create/foundation/tileEntity/behaviour/inventory/InvManipulationBehaviour.java
+++ b/src/main/java/com/simibubi/create/foundation/tileEntity/behaviour/inventory/InvManipulationBehaviour.java
@@ -107,12 +107,19 @@ public class InvManipulationBehaviour extends TileEntityBehaviour {
 			return ItemStack.EMPTY;
 
 		Predicate<ItemStack> test = getFilterTest(filter);
-		ItemStack extract = ItemStack.EMPTY;
-		if (amount != -1)
-			extract = ItemHelper.extract(inventory, test, amount, shouldSimulate);
-		else
-			extract = ItemHelper.extract(inventory, test, amountThreshold, shouldSimulate);
-		return extract;
+
+		ItemStack simulatedItems = extractAmountOrThresh(inventory, test, amount, amountThreshold, true);
+		if (shouldSimulate || simulatedItems.isEmpty())
+			return simulatedItems;
+
+		return extractAmountOrThresh(inventory, test, amount, amountThreshold, false);
+	}
+
+	private static ItemStack extractAmountOrThresh(IItemHandler inventory, Predicate<ItemStack> test, int amount,
+	   Function<ItemStack, Integer> amountThreshold, boolean shouldSimulate) {
+		if (amount == -1)
+			return ItemHelper.extract(inventory, test, amountThreshold, shouldSimulate);
+		return ItemHelper.extract(inventory, test, amount, shouldSimulate);
 	}
 
 	public ItemStack insert(ItemStack stack) {
@@ -156,7 +163,7 @@ public class InvManipulationBehaviour extends TileEntityBehaviour {
 		if (!targetCapability.isPresent())
 			findNewCapability();
 	}
-	
+
 	@Override
 	public void tick() {
 		super.tick();