Crash when extinguishing/igniting campfire using dispenser with Backhand installed

[huihiuhuai]

https://pastebin.com/TqXR2YGN

[connor135246]

This is an incompatibility with Campfire Backport in case that wasn't clear. The crash occurs because I use a FakePlayer to damage the item in the dispenser, and the FakePlayer doesn't have an offhand.

This bug isn't exclusive to Campfire Backport. I've been able to cause the same crash with EnderIO's Killer Joe block (it attacks mobs automatically). There may be other blocks that have this issue.

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Details:

I use a FakePlayer to do a couple things when extinguishing/igniting the campfire from a dispenser.
It looks like Backhand excludes FakePlayers from getting the offhand extended entity property:

Backhand/src/main/java/mods/battlegear2/BattlemodeHookContainerClass.java

Lines 70 to 75 in 23dd30c

	@SubscribeEvent(priority = EventPriority.HIGHEST)
	public void onEntityConstructing(EntityEvent.EntityConstructing event) {
	if (!(event.entity instanceof EntityPlayer && ! (isFake(event.entity))))
	return;
	event.entity.registerExtendedProperties("OffhandStorage",new OffhandExtendedProperty((EntityPlayer) event.entity));
	}

So when I try to damage the item, this patch tries to get the offhand item on line 81:

Backhand/src/main/java/net/tclproject/mysteriumlib/asm/fixes/MysteriumPatchesFixesO.java

Lines 74 to 81 in 23dd30c

	@Fix(insertOnExit = true)
	public static void damageItem(ItemStack itemStack, int p_77972_1_, EntityLivingBase p_77972_2_)
	{
	if (!(p_77972_2_ instanceof EntityPlayer) || itemStack == null)
	return;
	EntityPlayer player = (EntityPlayer) p_77972_2_;
	ItemStack offhandItem = BattlegearUtils.getOffhandItem(player);

And then there's a null pointer exception on line 79 here:

Backhand/src/main/java/mods/battlegear2/api/core/BattlegearUtils.java

Lines 75 to 79 in 23dd30c

	public static ItemStack getOffhandItem(EntityPlayer player) {
	if (Backhand.UseInventorySlot) {
	return player.inventory.getStackInSlot(Backhand.AlternateOffhandSlot);
	} else {
	return getOffhandEP(player).getOffhandItem();

Because this returns null:

Backhand/src/main/java/mods/battlegear2/api/core/BattlegearUtils.java

Lines 83 to 85 in 23dd30c

	public static OffhandExtendedProperty getOffhandEP(EntityPlayer player) {
	return ((OffhandExtendedProperty)player.getExtendedProperties("OffhandStorage"));
	}

So I think some null checks around getting the offhand property would be a good way to fix it.