Fix fluid stack not doubling (#151)

src/main/java/com/glodblock/github/client/gui/container/base/FCContainerEncodeTerminal.java

@@ -525,10 +525,18 @@ public abstract class FCContainerEncodeTerminal extends ContainerItemMonitor
 
     static boolean canDouble(SlotFake[] slots, int mult) {
         for (Slot s : slots) {
-            if (s.getStack() != null) {
-                long result = (long) s.getStack().stackSize * mult;
-                if (result > Integer.MAX_VALUE) {
-                    return false;
+            ItemStack st = s.getStack();
+            if (st != null) {
+                if (st.getItem() instanceof ItemFluidPacket) {
+                    long result = (long) ItemFluidPacket.getFluidAmount(st) * mult;
+                    if (result > Integer.MAX_VALUE) {
+                        return false;
+                    }
+                } else {
+                    long result = (long) s.getStack().stackSize * mult;
+                    if (result > Integer.MAX_VALUE) {
+                        return false;
+                    }
                 }
             }
         }
@@ -540,8 +548,11 @@ public abstract class FCContainerEncodeTerminal extends ContainerItemMonitor
         for (final Slot s : enabledSlots) {
             ItemStack st = s.getStack();
             if (st != null) {
-                st.stackSize *= mult;
-                s.putStack(st);
+                if (st.getItem() instanceof ItemFluidPacket) {
+                    ItemFluidPacket.setFluidAmount(st, ItemFluidPacket.getFluidAmount(st) * mult);
+                } else {
+                    st.stackSize *= mult;
+                }
             }
         }
     }

src/main/java/com/glodblock/github/common/item/ItemFluidPacket.java

@@ -12,6 +12,7 @@ import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumChatFormatting;
 import net.minecraft.util.IIcon;
 import net.minecraft.util.StatCollector;
+import net.minecraftforge.common.util.Constants;
 import net.minecraftforge.fluids.Fluid;
 import net.minecraftforge.fluids.FluidRegistry;
 import net.minecraftforge.fluids.FluidStack;
@@ -88,6 +89,22 @@ public class ItemFluidPacket extends FCBaseItem {
         return stack != null ? getFluidStack(stack.getItemStack()) : null;
     }
 
+    public static void setFluidAmount(ItemStack stack, int amount) {
+        if (stack == null || !stack.hasTagCompound()
+                || stack.getTagCompound().hasKey("FluidStack", Constants.NBT.TAG_COMPOUND)) {
+            return;
+        }
+        stack.getTagCompound().getCompoundTag("FluidStack").setInteger("Amount", amount);
+    }
+
+    public static int getFluidAmount(ItemStack stack) {
+        if (stack == null || !stack.hasTagCompound()) {
+            return 0;
+        }
+        // Default to 0 if no tag exists
+        return stack.getTagCompound().getCompoundTag("FluidStack").getInteger("Amount");
+    }
+
     @Nullable
     public static ItemStack newStack(@Nullable FluidStack fluid) {
         if (fluid == null || fluid.amount == 0) {