When a TNT block is placed next to a trapped chest, and specific item swaps are performed while the TNT is activated, there is a chance that an extra grass block will appear after the explosion. Both resulting grass blocks are fully usable. This issue does not occur every time and appears to be probability-dependent.
Steps to Reproduce:
Place a trapped chest next to a TNT block.
Prepare the following items:
A podzol block inside the trapped chest.
A grass block in the 9th slot of your hotbar.
Trigger the TNT (e.g., by powering the trapped chest).
While the TNT is counting down, repeatedly swap the podzol from the chest and the grass block from the hotbar (moving them back and forth).
Wait for the TNT to explode.
Repeat steps 3–5 multiple times, as the issue occurs only occasionally.
Observed Result:
After the explosion, there is a chance that two grass blocks will appear instead of one. Both can be placed and function normally.
Expected Result:
No item duplication should occur. Only one grass block should remain.
Attachments
Comments 2
I’ve tested this in multiple versions, and it seems to work in every single release version, and even beta, and it works with regular chests:
26.1.1 - Bug occurs as stated.
1.21.11 - Bug occurs as stated.
1.12.2 - Bug occurs as stated, although is much harder to achieve as holding the number key swaps much slower.
1.7.2 - Bug occurs as stated, although is much harder to achieve as you must click between the items quickly rather than holding a button.
1.5 - Bug occurs, though the overwritten duplicated item is truly a duplicate, not a bugged version of the block, and will stack with the original.
1.0 - Bug occurs, even in a version before trapped chests were implemented, can be done with a regular Chest and a block of TNT, creates true duplicate much like 1.5.
Beta 1.8.1 - Bug occurs, though the duplicated item cannot be picked up at all.
Can confirm this works, holding the '9' key to quick swap the two blocks make it a lot more consistent (still only works about 1/4 of the time)
It seems like less of a duplication glitch and more like it temporarily replacing one block with a copy of the other, since picking up the dropped block doesn’t automatically stack with the one in your hotbar, and
placing down the glitched block, or moving it around in your inventory returns it to its original state. It also works with blocks other than Podzol and Grass Blocks. Also works in both survival and creative mode.