Check item and capability before attempting to extract/insert (#2731)

Author: ALongStringOfNumbers

src/main/java/gregtech/api/metatileentity/MetaTileEntity.java

@@ -1162,6 +1162,10 @@ public void fillInternalTankFromFluidContainer() {
     public void fillInternalTankFromFluidContainer(IFluidHandler fluidHandler) {
         for (int i = 0; i < importItems.getSlots(); i++) {
             ItemStack inputContainerStack = importItems.extractItem(i, 1, true);
+            if (inputContainerStack.isEmpty() ||
+                    !inputContainerStack.hasCapability(CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null)) {
+                continue;
+            }
             FluidActionResult result = FluidUtil.tryEmptyContainer(inputContainerStack, fluidHandler, Integer.MAX_VALUE,
                     null, false);
             if (result.isSuccess()) {
@@ -1184,6 +1188,10 @@ public void fillContainerFromInternalTank() {
     public void fillContainerFromInternalTank(IFluidHandler fluidHandler) {
         for (int i = 0; i < importItems.getSlots(); i++) {
             ItemStack emptyContainer = importItems.extractItem(i, 1, true);
+            if (emptyContainer.isEmpty() ||
+                    !emptyContainer.hasCapability(CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null)) {
+                continue;
+            }
             FluidActionResult result = FluidUtil.tryFillContainer(emptyContainer, fluidHandler, Integer.MAX_VALUE, null,
                     false);
             if (result.isSuccess()) {