The bug

For some plants when the block supporting it is instantly (e.g. using 0-ticks) replaced with the same block type the plant will grow.

The expected behavior is that the the plant should break, or that nothing special should happen.

As it currently stands this behavior allows for mass duplication of these items on the order of tens of thousands of items per hour. Far, far faster than any conventional farming method.

This bug may relate to MC-165023 where crop growth is randomly updated via falling sand on boats.

Affected plants

How to reproduce

Set the value for the gamerule randomTickSpeed to 0 /gamerule randomTickSpeed 0 Build a contraption like the one shown in Chorus flower update setup (17w06a).png

Code analysis

Based on 1.13.1 decompiled using MCPConfig