Pocketmine-mp: BaseInventory->addItem() with a list of separate, stackable items puts each stack in its own slot

[dktapps]

Issue description

$inventory->addItem(
    Item::get(Item::PLANKS, 0, 16),
    Item::get(Item::PLANKS, 0, 16),
    Item::get(Item::PLANKS, 0, 16),
    Item::get(Item::PLANKS, 0, 16)
);

will put each of the stacks in a separate slot instead of combining them as expected.

Steps to reproduce the issue

1. use the above code
2. profit

[jasonwynn10]

Why should the stacks combine instead of be individual?

[dktapps]

because that is vanilla behaviour. The current behaviour is off and quite annoying. You can see it when you close a crafting grid after failing to craft something.