Wierd bug with null string

06-03-2007, 06:30 AM

I'm having a really wierd bug with a null string. Ill post the code first then fill you all in.

JASS:

private function UnitToChat takes nothing returns nothing
    local unit u = NPCunit[toNPC]
    local real x1 = GetUnitX(u)
    local real y1 = GetUnitY(u)
    local real x2 = GetUnitX(heroUnit)
    local real y2 = GetUnitY(heroUnit)
    local string key = KEY_NPC+I2S(toNPC)
    local integer chat = GetStoredInteger(ESE_cache, key, KEY_NPC_WANT_CHAT)
    if toNPC!=0 then        
        if SquareRoot((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)) <= NPC_TALK_DISTANCE then
            if chat!=0 then
                call displayChat(chat, GetStoredString(ESE_cache, key, KEY_NPC_NAME))
                call DestroyEffect(NPCeffect[toNPC])
                call FlushStoredInteger(ESE_cache, key, KEY_NPC_WANT_CHAT)   
            else
                call displayChat(GetStoredInteger(ESE_cache, key, KEY_NPC_CHAT), GetStoredString(ESE_cache, key, KEY_NPC_NAME))
            endif
            call SetUnitFacing(u, bj_RADTODEG*Atan2(y2-y1, x2-x1))
            call BJDebugMsg(NPCcam[toNPC])
            if NPCcam[toNPC] != "" then
                call BJDebugMsg("Code Exists!")
                set tempNPC = u
                call ExecuteFunc(NPCcam[toNPC])
            endif
            set toNPC = 0
            call IssueImmediateOrder(heroUnit, "stop")
            call SetUnitFacing(heroUnit, bj_RADTODEG*Atan2(y1-y2, x1-x2))
            call PauseUnit(heroUnit, true)   
        else
            call IssuePointOrder(heroUnit, "move", x1, y1)
            call TimerStart(NPC_Timer, NPC_PERIOD, false, function UnitToChat)
        endif
    endif
    set u = null
endfunction 

private function npcOrdered takes nothing returns nothing
    local unit u = GetTriggerUnit()
    local integer i = GetUnitUserData(u)
    local real x1 = GetUnitX(u)
    local real y1 = GetUnitY(u)
    local real x2 = GetUnitX(heroUnit)
    local real y2 = GetUnitY(heroUnit)
    local string key = KEY_NPC+I2S(i)
    local integer chat = GetStoredInteger(ESE_cache, key, KEY_NPC_WANT_CHAT)
    if i!=0 and not chatVisible then        
        if SquareRoot((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)) <= NPC_TALK_DISTANCE then
            set questVisible = false
            if chat!=0 then
                call displayChat(chat, GetStoredString(ESE_cache, key, KEY_NPC_NAME))
                call DestroyEffect(NPCeffect[i])
                call FlushStoredInteger(ESE_cache, key, KEY_NPC_WANT_CHAT)   
            else
                call displayChat(GetStoredInteger(ESE_cache, key, KEY_NPC_CHAT), GetStoredString(ESE_cache, key, KEY_NPC_NAME))
            endif
            call SetUnitFacing(u, bj_RADTODEG*Atan2(y2-y1, x2-x1))
            call SetUnitFacing(heroUnit, bj_RADTODEG*Atan2(y1-y2, x1-x2))
            call BJDebugMsg(NPCcam[toNPC])
            if NPCcam[toNPC] != "" then
                call BJDebugMsg("Code Exists!")
                set tempNPC = u
                call ExecuteFunc(NPCcam[toNPC])
            endif
            call PauseUnit(heroUnit, true)   
        else
            set toNPC = i
            call IssuePointOrder(heroUnit, "move", x1, y1)
            call TimerStart(NPC_Timer, NPC_PERIOD, false, function UnitToChat)
        endif
    endif
    set u = null
endfunction

The first function works fine, and is used within a loop to check when the unit does come within range of the NPC unit. The second function fires through a selection event trigger. Both work fine except for the highlighted parts.

The cream highlight is the problem-ed if/then/else check. For some reason, even if the string is null, it will still run. It is the same lines of code, copied directly from the first function. Now, the problem is that if the string is null and it passes the check, it will try to run a function of name null. This crashes the game.

I've tried re-copying the problem-ed lines of code multiple times, and still no luck. Help?

06-20-2007, 03:35 AM	#2
Here-b-Trollz	Well, all I know is that I've had a few instances where if then's bug out, and sometimes it is best to use an "==true". I have no idea why though. -.-*

06-20-2007, 04:44 AM	#3
Vexorian	oh noh no more ==true non-sense that's totally unrelated to this. And it is perfectly safe not to use ==true inside if conditions. . There are 2 "null strings" , one is null and ""

06-20-2007, 06:06 AM	#4
Ammorth	I don't have to worry about a null string, since the string is never used unless it is set to "" or some other value. The issue was that both functions used the same method to check, yet they yielded different results. This really doesn't matter anymore because I think I found a way around it. I've also taking some time off of modding to study for finals.