When saving data about a column of blocks at 0, 0 (XZ), all blocks in the structure file get saved as having the same coordinate - the top of the column. As a result, when loading this structure only the top block gets set correctly.

The position of the structure block does not appear to matter, only the position of the structure does.

Steps to reproduce:

• Create a void world.
• Go to 0, 0.
• Place a few blocks at 0, 0, 0 and in a pillar upwards.
• Place a structure block and set it to save the pillar.
• Destroy the pillar, switch the structure block over to load and attempt to load the structure.

Result:

• Note that all blocks except the top one fail to load.

Expected result:

• All the blocks load.

The exact same repro case works as intended if you move it one block over from 0, 0.

I've attached a world file with this exact setup (1.10.2) - Test and Test3 are both generated from the column at 0, 0 by two structure blocks, one above and one to the side of the column. Test2 is an identical copy of Test, shifted one block over.

The same bug is also present in 16w40a.