A minor bug with the vanilla dispenser in the following setup:
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Note: the hopper does not need to receive mechanical power for this bug.
When the inventory of the hopper is completely filled and the button is pushed, the dispenser will dispense two items out of its inventory (one when it receives the redstone signal, and one when the redstone signal stops). Placing a block next to the dispenser seems to trigger it to dispense something as well.
Verified, also verified this happens with unpowered hopper (but not unfilled hopper) and verified this doesn't happen with just the dispenser, but if the dispenser has a steady redstone signal (like the filled hopper would give) this will happen.
Basically if the dispenser is being powered (i.e. signal from the filled hopper) and then receives a redstone update (the button's pulse ending) it dispenses twice. Once for the pulse itself and once as the redstone turns off.
Exactly. If the Dispenser is powered, any redstone update will cause it to fire. So an ON-OFF signal will cause it to fire twice (2 updates).
Not a bug.
