Solved TFS 1.2 interesting bug with destroy.lua onDestroyItem, added video and ss to explain

[Shadow Dan]

Lua Script Error: [Action Interface]
data/actions/scripts/other/destroy.lua:onUse
data/actions/lib/actions.lua:89: attempt to call method 'isItem' (a nil value)
stack traceback:
        [C]: in function 'isItem'
        data/actions/lib/actions.lua:89: in function <data/actions/lib/actions.lua:88>

If you stand on this position and use sword (or any weapon that uses script destroy.lua) on wall
red = bug in console
green = no bug all fine

So bug happens when you are behind the wall and use sword on it.
actions/lib/actions.lua

88 function onDestroyItem(player, item, fromPosition, target, toPosition, isHotkey)
89     if not target or not target:isItem() then
90         return false
91     end

destroy.lua

function onUse(player, item, fromPosition, target, toPosition, isHotkey)
    return onDestroyItem(player, item, fromPosition, target, toPosition, isHotkey)
end

I couldn't explain it easier, maybe it's known bug or not, let's see what scripters will say. I'm really curious why that happens.

#I'll edit soon to add video. It's in progress to be available.

 

[RazorBlade]

I would have to assume it's to do with walls being inaccessible from one side. Imagine if you could access the item on the wall. If there was a trophy or tapestry there, you could take it. I believe it considers the item to be nil if accessing it from that side, and thus, target is not a thing, so isItem() cannot be called on it. If you do Item(target):isItem() it should stop erroring.

 

[Shadow Dan]

If i do:

if not target or not Item(target):isItem() then

it is erroring from every side.

Lua Script Error: [Action Interface]
data/actions/scripts/other/destroy.lua:onUse
data/actions/lib/actions.lua:89: attempt to index a nil value
stack traceback:
        [C]: in function '__index'
        data/actions/lib/actions.lua:89: in function <data/actions/lib/actions.lua:88>

I'm waiting for more ideas.

 

[RazorBlade]

hm. I'll try on my server and see what happens.

 

[RazorBlade]

this is my actions.lua

function destroyItem(player, target, toPosition)
    if target == nil or not target:isItem() then
        return false
    end

    if target:hasAttribute(ITEM_ATTRIBUTE_UNIQUEID) or target:hasAttribute(ITEM_ATTRIBUTE_ACTIONID) then
        return false
    end

    if toPosition.x == CONTAINER_POSITION then
        player:sendCancelMessage(Game.getReturnMessage(RETURNVALUE_NOTPOSSIBLE))
        return true
    end

    local destroyId = ItemType(target.itemid):getDestroyId()
    if destroyId == 0 then
        return false
    end

    if math.random(7) == 1 then
        local item = Game.createItem(destroyId, 1, toPosition)
        if item ~= nil then
            item:decay()
        end

        -- Move items outside the container
        if target:isContainer() then
            for i = target:getSize() - 1, 0, -1 do
                  local containerItem = target:getItem(i)
                if containerItem then
                    containerItem:moveTo(toPosition)
                end
            end
        end

        target:remove(1)
    end

    toPosition:sendMagicEffect(CONST_ME_POFF)
    return true
end

 

[Lordfire]

You do not need to use "Item(target):isItem()", "Item(target)" is enough.

 

[Ninja]

You may wonder why target is unable to call the method isItem, and it's because target becomes an array when it's being targeted from an "inaccessable" position.

Edit:

You can make the error disappear by changing

if not target or not target:isItem() then

to

if not target or type(target) ~= "userdata" or not target:isItem() then

 

[Shadow Dan]

Someone create issue on github, i created issue and its closed because of invaild label. Dunno which label is correct.

 

[RazorBlade]

I don't believe it's an issue, as I posted, my actions.lua is different. As is the one on the github. I think yours is just outdated. Update and see if it works.

 

[Shadow Dan]

My lib/actions.lua has 670 lines and yours 41.
I have lastest files from github.

Btw. i tested your code and same error so please don't say its fault because of outdated files.
I downloaded it few days ago.

 

[RazorBlade]

Might I ask where you got it?
https://github.com/otland/forgottenserver/blob/master/data/actions/lib/actions.lua

Edit:
No wonder your issue was closed by Mark. This is an ORTS issue, not a TFS issue. As for a solution, Ninjabuddy seems to have posted one and being that he's a smartypants, I would give it a try

 

[Shadow Dan]

I tested twice code from TFS and it's still same error.

Edit:

You can make the error disappear by changing

if not target or not target:isItem() then

to

if not target or type(target) ~= "userdata" or not target:isItem() then

That fixed my error, thank you Ninja!

 

[Blasphemy]

I tested twice code from TFS and it's still same error.


That fixed my error, thank you Ninja!

@Shadow Dan , did you applied both arrangements?

from Ninja and Lordfire?

 

[Shadow Dan]

    if not target or type(target) ~= "userdata" or not target:isItem() then
        return false
    end

 

[jaicob]

Well i don't like bumping old threads but i ran into the same problem and found out why, I'm working on a comletely custom ot where i cleaned all my sprites and items in item.otb and tibia.dat, and for those who also have this problem my problem was that i just needed to change the item to multi use in item.otb (was making a schythe that should destoy hay :>