LuaObject's Call metamethod is not passed in Self

[XILO1106]

When I use LuaObject

[LuaMetamethod(LuaObjectMetamethod.Call)]
public void Func() {}

to declare the meta method
object() call,

error: bad argument #1 to 'call' (value expected)

It's going to be object(object)

[nuskey8]

Could you please provide more detailed Lua/C# code? This comment alone doesn't allow us to pinpoint the exact cause.

[XILO1106]

Could you please provide more detailed Lua/C# code? This comment alone doesn't allow us to pinpoint the exact cause.能否提供更详细的Lua/C#代码？仅凭此评论并不能让我们查明确切原因。

Technically, at lua

local MyTable = {}
local MyMetatable = {}
MyMetatable.__call = function(self)
print(self)
end

setmetatable(MyTable, MyMetatable)

MyTable()

table:0x.... will be printed
Because when you call MyTable() you automatically pass in MyTable as self

But in C#:

[LuaObject]
[LuaMetamethod(LuaObjectMetamethod.Call)]
public void _Call()
{
Console.Write("Hello LuaObject");
}

Lua:

TestLuaObject()

Will report an error test1.lua:1: bad argument #1 to 'call' (value expected)

Must be written
TestLuaObject(TestLuaObject) -- Hello LuaObject

The __call meta-method of the class we declare in C# requires us to pass self ourselves, This does not conform to lua.

[SyBozzDEV]

I found that when creating an lua object with __call in the metatable in lua it also is missing the table as the first parameter.

local t = setmetatable({}, {
    __call = function(tb)
        print(tb)
    end
})

t()

Expected result would be -> table: xyz
Actual result -> nil

Source Code --------------------------------------------------
local t = setmetatable({
}
, {
    __call = function(tb)
        print(tb)
    end
    
}
)
t()

Chunk[0]==================================================
Parameters:0
Instructions --------------------------------------------------
[0]     (1,10)          GETTABUP  0 0 256
[1]     (1,23)          NEWTABLE  1 0 0
[2]     (1,27)          NEWTABLE  2 0 1
[3]     (2,13)          CLOSURE   3 0
[4]     (2,4)           SETTABLE  2 257 3
[5]     (1,10)          CALL      0 3 2
[6]     (7,0)           MOVE      1 0
[7]     (7,0)           CALL      1 1 1
[8]     (7,0)           RETURN    0 1
Constants --------------------------------------------------
[0]     setmetatable
[1]     __call
UpValues --------------------------------------------------
[0]     _ENV    0       -1

Chunk[0]==================================================
Parameters:1
Instructions --------------------------------------------------
[0]     (3,8)           GETTABUP  1 0 256
[1]     (3,14)          MOVE      2 0
[2]     (3,8)           CALL      1 2 1
[3]     (3,8)           RETURN    0 1
Constants --------------------------------------------------
[0]     print
UpValues --------------------------------------------------
[0]     _ENV    0       0

Output --------------------------------------------------
nil
Result --------------------------------------------------
End --------------------------------------------------

I just started to read a bit into the lua instructions / opcodes.
I checked with luac(dot)nl on version 5.2.4 and get the same source tree.

On line 7 we have a move and a call, where the call indicates no arguments (as expected) but we got the table loaded by the previous move instruction (if I understand it correctly).
So I think the problem is in the lua vm handeling the call instruction, as the argument count / argument was set by the previous instruction.

I hope this is somewhat helpful, as I didn't get any further information debugging it due to missing knowledge/understanding.
I'm not even completely sure it's the same problem of the issue but I just assume it is.