$ cat tools/semgrep-rules/dupe-ghost-inventory.yaml 
rules:
  - id: mcla-find-ghost-inventory-dupes
    message: >-
      This might be a ghost inventory dupe.
    severity: WARNING
    languages:
      - lua
    pattern: |
      $X = minetest.get_meta(...);
      ...
      $Y = $X;
      ...
      $X.from_table(...);
      ...
      $X.from_table($Y:to_table());
$ semgrep --config tools/seemgrep-rules/dupe-ghost-inventory.yaml --max-lines-per-finding 20
Scanning 306 files.
  100%|███████████████████████████████████████████████████████████|306/306 tasks

Findings:

  mods/ITEMS/REDSTONE/mcl_dispensers/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


         84┆ local meta = minetest.get_meta(pos)
         85┆ local meta2 = meta
         86┆ meta:from_table(oldmetadata)
         87┆ local inv = meta:get_inventory()
         88┆ for i=1, inv:get_size("main") do
         89┆ 	local stack = inv:get_stack("main", i)
         90┆ 	if not stack:is_empty() then
         91┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
         92┆ 		minetest.add_item(p, stack)
         93┆ 	end
         94┆ end
         95┆ meta:from_table(meta2:to_table())


  mods/ITEMS/REDSTONE/mcl_droppers/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


         57┆ local meta = minetest.get_meta(pos)
         58┆ local meta2 = meta
         59┆ meta:from_table(oldmetadata)
         60┆ local inv = meta:get_inventory()
         61┆ for i=1, inv:get_size("main") do
         62┆ 	local stack = inv:get_stack("main", i)
         63┆ 	if not stack:is_empty() then
         64┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
         65┆ 		minetest.add_item(p, stack)
         66┆ 	end
         67┆ end
         68┆ meta:from_table(meta2:to_table())


  mods/ITEMS/REDSTONE/mcl_droppers/init_new.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


         55┆ local meta = minetest.get_meta(pos)
         56┆ local meta2 = meta
         57┆ meta:from_table(oldmetadata)
         58┆ local inv = meta:get_inventory()
         59┆ for i=1, inv:get_size("main") do
         60┆ 	local stack = inv:get_stack("main", i)
         61┆ 	if not stack:is_empty() then
         62┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
         63┆ 		minetest.add_item(p, stack)
         64┆ 	end
         65┆ end
         66┆ meta:from_table(meta2:to_table())


  mods/ITEMS/mcl_anvils/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


        321┆ local meta = minetest.get_meta(pos)
        322┆ local meta2 = meta
        323┆ meta:from_table(oldmetadata)
        324┆ drop_anvil_items(pos, meta)
        325┆ meta:from_table(meta2:to_table())


  mods/ITEMS/mcl_chests/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


        348┆ local meta = minetest.get_meta(pos)
        349┆ local meta2 = meta
        350┆ if oldmetadata then
        351┆ 	meta:from_table(oldmetadata)
        352┆ end
        353┆ local inv = meta:get_inventory()
        354┆ for i=1,inv:get_size("main") do
        355┆ 	local stack = inv:get_stack("main", i)
        356┆ 	if not stack:is_empty() then
        357┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
        358┆ 		minetest.add_item(p, stack)
        359┆ 	end
        360┆ end
        361┆ meta:from_table(meta2:to_table())


  mods/ITEMS/mcl_furnaces/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


        453┆ local meta = minetest.get_meta(pos)
        454┆ local meta2 = meta
        455┆ meta:from_table(oldmetadata)
        456┆ local inv = meta:get_inventory()
        457┆ for _, listname in ipairs({"src", "dst", "fuel"}) do
        458┆ 	local stack = inv:get_stack(listname, 1)
        459┆ 	if not stack:is_empty() then
        460┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
        461┆ 		minetest.add_item(p, stack)
        462┆ 	end
        463┆ end
        464┆ meta:from_table(meta2:to_table())
          ⋮┆----------------------------------------
        529┆ local meta = minetest.get_meta(pos)
        530┆ local meta2 = meta
        531┆ meta:from_table(oldmetadata)
        532┆ local inv = meta:get_inventory()
        533┆ for _, listname in ipairs({"src", "dst", "fuel"}) do
        534┆ 	local stack = inv:get_stack(listname, 1)
        535┆ 	if not stack:is_empty() then
        536┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
        537┆ 		minetest.add_item(p, stack)
        538┆ 	end
        539┆ end
        540┆ meta:from_table(meta2:to_table())


  mods/ITEMS/mcl_hoppers/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


         63┆ local meta = minetest.get_meta(pos)
         64┆ local meta2 = meta
         65┆ meta:from_table(oldmetadata)
         66┆ local inv = meta:get_inventory()
         67┆ for i=1,inv:get_size("main") do
         68┆ 	local stack = inv:get_stack("main", i)
         69┆ 	if not stack:is_empty() then
         70┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
         71┆ 		minetest.add_item(p, stack)
         72┆ 	end
         73┆ end
         74┆ meta:from_table(meta2:to_table())
          ⋮┆----------------------------------------
        251┆ local meta = minetest.get_meta(pos)
        252┆ local meta2 = meta
        253┆ meta:from_table(oldmetadata)
        254┆ local inv = meta:get_inventory()
        255┆ for i=1,inv:get_size("main") do
        256┆ 	local stack = inv:get_stack("main", i)
        257┆ 	if not stack:is_empty() then
        258┆ 		local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
        259┆ 		minetest.add_item(p, stack)
        260┆ 	end
        261┆ end
        262┆ meta:from_table(meta2:to_table())


  mods/ITEMS/mcl_jukebox/init.lua 
     tools.semgrep-rules.mcla-find-ghost-inventory-dupes
        This might be a ghost inventory dupe.


        200┆ local meta = minetest.get_meta(pos)
        201┆ local meta2 = meta
        202┆ meta:from_table(oldmetadata)
        203┆ local inv = meta:get_inventory()
        204┆ local stack = inv:get_stack("main", 1)
        205┆ if not stack:is_empty() then
        206┆ 	local p = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
        207┆ 	local dropped_item = minetest.add_item(p, stack)
        208┆ 	-- Rotate record to match with “slot” texture
        209┆ 	dropped_item:set_yaw(math.pi/2)
        210┆ 	if active_tracks[name] ~= nil then
        211┆ 		minetest.sound_stop(active_tracks[name])
        212┆ 		active_tracks[name] = nil
        213┆ 	end
        214┆ 	if active_huds[name] ~= nil then
        215┆ 		digger:hud_remove(active_huds[name])
        216┆ 		active_huds[name] = nil
        217┆ 	end
        218┆ end
        219┆ meta:from_table(meta2:to_table())

Some files were skipped.
  Scan was limited to files tracked by git.

Ran 1 rule on 306 files: 10 findings.