[2.0.72] LuaSurface::clone_area skips some trees on ore during cloning

Data · Post by **Data** » Thu Jan 15, 2026 5:04 am

What did you do?

Run Factorio 2.0.72, base game without mods and without Space age DLC
Single Player > New Game > Freeplay
Set seed to 4288898516 (any seed will work, but you need to find an ore patch with fair amount of trees over it)
Start the game with default settings
Skip the cutscene
Run the command (twice to suppress achievements disable warning):
Code: Select all
```
/editor
```
Run the command, which will position you on an ore patch with some trees:
Code: Select all
```
/c game.player.teleport({255,560})
```
Don't move and wait for nearby chunks to be generated

Run the command, which will copy using LuaSurface::clone_area the middle of the observed area to the right side and create some out-of-map gaps for easier visual inspection:

Code: Select all

/c
local pos = {x = math.floor(game.player.position.x), y = math.floor(game.player.position.y)}

local size = 64
local gap = 8

local area = {left_top = {pos.x - size/2, pos.y - size/2}, right_bottom = {pos.x + size/2, pos.y + size/2},}
local dest_area = {
    left_top = {area.left_top[1] + size + gap, area.left_top[2]},
    right_bottom = {area.right_bottom[1] + size + gap, area.right_bottom[2]},
}

local gap_tiles = {}
for y = 0, size-1 do
    for x = 0, gap-1 do
        gap_tiles[#gap_tiles+1] = { name = 'out-of-map', position = { area.left_top[1] - gap + x, area.left_top[2] + y } }
    end
end
for y = 0, size-1 do
    for x = 0, gap-1 do
        gap_tiles[#gap_tiles+1] = { name = 'out-of-map', position = { area.right_bottom[1] + x, area.left_top[2] + y } }
    end
end
for y = 0, size-1 do
    for x = 0, gap-1 do
        gap_tiles[#gap_tiles+1] = { name = 'out-of-map', position = { dest_area.right_bottom[1] + x, dest_area.left_top[2] + y } }
    end
end
game.player.surface.set_tiles(gap_tiles)

local request = {
    source_area = area,
    destination_area = dest_area,
    destination_surface = game.player.surface,
    clone_tiles = true,
    clone_entities = true,
    clone_decoratives = true,
    clear_destination_entities = true,
    clear_destination_decoratives = true,
    create_build_effect_smoke = false,
    expand_map = true,
}
game.player.surface.clone_area(request)

Observe how destination area has less trees on ore patch than original source area

What happened?
LuaSurface::clone_area has failed to properly clone trees on ore (see screenshots attached)

What did you expect to happen instead?
All trees are copied

Does it happen always, once, or sometimes?
It always happens, but unfortunately it's not 1-to-1 reproducible on default map generation duo to this bug, which was marked as duplicate of another bug

Notes

Bug is reproducible in it's nature, you can save before running the last command, reload and run the command again: given same ores and trees it will fail to clone the same trees. But if you run the command without reloading (effectively overriding the copy of the original area), each time clone_area will skip different trees
Seems like trees outside of ore are unaffected and properly cloned
Painfully resembles already mentioned bug