Variable Acting Wrong After Updating Lua/IUP

Hello,

I'm having a problem with a variable after updating an old app from Lua 5.0/IUP 2.4 to Lua 5.1/IUP 3.30.

In the old version, the variable behaves the way I want, but in the updated version, it decrements by 1 and I can't figure out why.

I tried checking https://www.lua.org/manual/5.1/manual.html#7 and https://www.tecgraf.puc-rio.br/iup/en/migration_guide.html

for ideas about what might've changed, but couldn't find anything. I'm guessing it's probably a Lua issue, unless there's some

change to iup.list that could be affecting this.

I managed to create a stand-alone script that demonstrates the problem, but it's long because I'm fixing up an old app made

by someone more experienced than I, so there's a lot of complicated-looking nested arrays that made it difficult to come up

with something simpler.

How to trigger the problem: Run the script and for Offensive Power Type, select #3 ("Ranged"). Then, change Character Class to "Mage".

Some message boxes with info about the variables will pop up during an update function.

What I want to happen is despite the change in Class updating the Power Types available in box #2, the box #2 selection should remain

on item #3, although the item's text will change. That's how it works when I test it with Lua 5.0 and IUP 2.4.

What happens since the update is during the update function, when 'i' gets to iteration #3, the Power Types listbox value decrements to 2 and

shows "Cast Spell", while the "Available Powers" list is populated by the powers associated with the correct value, #3 ("Summon").

If you select Power Type #2 and then change Class, the same decrementing variable problem occurs, but happens at iteration #2, which

is also when one of the strings I'm watching via iup.Message updates to a new value.

I wrote some comments in the script with more details.

Does anyone know what might be causing this?

Lua script:

-----------------------------------------------------------------

require'iuplua'

local profile = "">

profile.__index = profile

local t = {}

t.className = "Warrior" --name of character class initially displayed in listbox #1

t.classNum = 1 --# corresponding to character class initially displayed in listbox #1

t.offensePowerType = 1 --# corresponding to the offensive power category initially displayed in listbox #2

setmetatable(t,profile) --in actual app, a Profile saves settings that can be loaded later

local dlg = {}

local powersBox = iup.list{size = "80x100"} --displays available powers based on choices made from listboxes

-- POWER TABLES -----------------------------------------------------------

local offensePowTypeTable = {

--These are displayed in listbox #2 and change depending on what character class is selected in listbox #1.

--I'm not sure why there's a separate table for this. Maybe to use ipairs instead of pairs?

--Warrior > Offense >

{"Brawl","Melee","Ranged"},

--Mage > Offense >

{"Use Potion","Cast Spell","Summon"}

}

local powersTable = {

["Warrior"] = {

["Offense"] = {

["Brawl"] = {

[1] = "Punch",

[2] = "Kick"

["Melee"] = {

[1] = "Swing Mace",

[2] = "Swing Sword"

["Ranged"] = {

[1] = "Shoot Bow",

[2] = "Throw Shuriken"

}

--["Defense"] = {} --table shortened for brevity

["Mage"] = {

["Offense"] = {

["Use Potion"] = {

[1] = "Heal",

[2] = "Boost Power"

["Cast Spell"] = {

[1] = "Shoot Fireball",

[2] = "Shoot Lightning Chain"

["Summon"] = {

[1] = "Not the Bees!",

[2] = "Call Demons"

}

--["Defense"] = {}

}

-- LIST CREATION/CONTROL FUNCTIONS -------------------------------------------------

local function makeListbox(label,list,val,callback) --creates a dropdown list with label and callback

local ttable = {}

for i = 1,#list do ttable[i] = list[i] end

ttable.dropdown = "YES"

ttable.value = val --what index should be selected(shown) in dropdown

local tlist = iup.list(ttable)

tlist.size = "100x"

tlist.action = "">

return iup.hbox{iup.label{title = label}, tlist}, tlist --function will return 2 results

end

local function updateListbox(listbox,newtable,inspect,getVal)

for i,v in ipairs(newtable) do

listbox[i] = v --copies the list from newtable to listbox

if inspect then --my makeshift debug method. I don't know much about debuggers.

iup.Message("t.offensePowerType #"..t.offensePowerType.." "..getVal[t.offensePowerType],

"Iteration #"..i..":"..

"\ntOffListbox["..i.."] == "..v..

"\ntOffListbox.value (selected): #"..getVal.value.." "..getVal[getVal.value])

-- I want 't.offensePowerType' and 'tOffListbox.value' to match so the selection stays in the same position

--regardless of the items in the list changing. When the mesg box shows that 'i' and 'tOffListbox.value' are about to equal

--each other, the number of 'tOffListbox.value' decrements by 1. That's also the moment that the value of

--'tOffListbox[t.offensePowerType]' swaps to the other character class's equivalent power type.

end

local function reloadPowListbox(t) --when user selects new class in listbox #1, change the list of power types in listbox #2

local powersList = {"Run","Jump"} --starts by adding basic abilities all classes have

for i,v in ipairs(powersTable[t.className]["Offense"][offensePowTypeTable[t.classNum][t.offensePowerType]]) do

--ex. powersTable > Warrior > Offense >? offensePowTypeTable > array 1: Warrior > index 1: Melee > iterate over warrior's offensive melee powers

--How is it possible to use ipairs on 2 tables like that? I don't understand the syntax.

table.insert(powersList,v)

end

t.powersList = powersList

end

-- CREATE AND PLACE ITEMS ------------------------------------------------------------

local tOff, tOffListbox = makeListbox("Offensive Power Types: ",offensePowTypeTable[t.classNum],t.offensePowerType,

function(_,str,i,v)

t.modified = true

if v == 1 then

t.offensePowerType = i

reloadPowListbox(t)

updateListbox(powersBox,t.powersList)

end

end)

--I don't know why 2 variables are being used. tOff is the label, hbox, listbox. tOffListbox is just the listbox.

--Can the listbox not be changed if enclosed in the hbox?

--Do tOffListbox and tOff refer to the same listbox or are there 2 identical copies of a listbox?

local tClassBox = makeListbox("Choose Character Class: ",{"Warrior","Mage"},t.classNum,

function(_,str,i,v)

t.modified = true

if v == 1 then --clicked on an item in list

t.className = str --stores the currently selected class name

t.classNum = i --is updated to hold current index number

updateListbox(tOffListbox,offensePowTypeTable[i],"inspect",tOffListbox)

reloadPowListbox(t)

updateListbox(powersBox,t.powersList) --update available powers box

end

)

table.insert(dlg,tClassBox)

table.insert(dlg,tOff)

reloadPowListbox(t)

updateListbox(powersBox,t.powersList)

local dialog = iup.dialog{title = "a dialog", iup.hbox{

iup.vbox(dlg), iup.vbox{iup.label{title = "Available Powers:"}, powersBox};

cgap = "5x5", ncmargin = "10x10"

}}

dialog:show()

if (iup.MainLoopLevel()==0) then

iup.MainLoop()

dialog:destroy()

iup.Close()

end