The bug
When summoning a falling block with another entity as a passenger (that passenger could be another falling block as well), that passenger will be inside of the block once the block lands on the ground. Before 1.14, it used to be ejected on top of the block.
Most noteworthy, this causes falling blocks riding other falling blocks to pop off as items instead of being placed, rendering so-called "one command creations" unusable.
How to reproduce
1. Example:
/summon minecraft:falling_block ~5 ~10 ~ {Time:1,BlockState:{Name:"minecraft:redstone_block"},Passengers:[{id:"minecraft:cow"}]}→ ❌ The cow will be inside of the block once the block lands
2. Example:
/summon minecraft:falling_block ~5 ~10 ~ {Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1}]}]}]}→ ❌ The sand blocks will be drop of the block once the first block lands
3. Example with more blocks:
/summon minecraft:falling_block ~5 ~10 ~ {Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1,Passengers:[{id:"minecraft:falling_block",Time:1}]}]}]}]}]}]}]}]}→ ❌ The sand blocks will be drop of the block once the first block lands
Linked issues
is duplicated by 11
MC-145310
Passenger Falling Blocks Break
Resolved
MC-148767
falling_blocks riding falling_blocks will not land correctly
Resolved
MC-150041
falling_block as Passengers of falling_blocks make phantom blocks
Resolved
MC-151804
Falling blocks that are passengers of falling blocks never land in 1.14
Resolved
MC-151873
falling_blocks riding falling_blocks will not land correctly
Resolved
Attachments
Comments 29
For those interested, I had not been able to find this bug, all I could find was a similar one with the new blocks destroying themselves. To show what was happening when I made a new bug post, I made this video: https://youtu.be/KpcxiOI0Bjs
This, if left in the game, would break a lot of commands.