If a stackable item has a 'tag' (such as custom names, lores, or enchantments), it can still be stacked and unstacked normally in the inventory. However, if you drop multiple instances of such an item on the ground, they do not stack.
This disrupts item detectors which rely on stacking mechanics, and thus limits the use of custom items in maps (yes, this is how I ran into the issue - so much for having magical relics that act as keys).
What I expected to happen was...:
The custom items should have joined together into a stack on the ground.
What actually happened was...:
The items did not stack on the ground, as though they were non-stackable.
Steps to Reproduce:
1. Take a stack of any item and rename it on an anvil.
2. Observe that the items can be unstacked and restacked freely in the inventory.
3. Drop the items on the ground. Observe that they do not stack.
4. Drop normal stackable items on the ground. Observe that they join to form a single stack. There may be some delay before this happens.
Linked issues
Comments
This bug is back, I guess, but this time it also doesn't stack in your inventory.
You scared me for a second, but when I tried, I couldn't reproduce. Are you sure the tags are exact? What tags are you using?
Note that if you anvil an item a different amount of times, it has a different internal anvil cost, meaning its NBT tags aren't the same.
I tried enchanting and renaming a sapling, and it stacked fine, in my inventory and on the ground.
Erik Broes
Fixed/resolved already?! Wow, that was really quick!
Thank you, Grum 😃
Cheers!