Null key problem (Run-time)

ID:1381524
 
Sep 21 2013, 6:26 am
(See the best response by Ter13.)
Code:
Small_Power(var/mob/new_player/M as mob in player_list)
            var/datum/CodersWork/Healing_Touch/HealingPower=new/datum/CodersWork/Healing_Touch()
            var/chance=5
            world<<"<font color =purple>A little bug has been seen, it may have infected someone with an unknown virus!"
            if(M.key=="Adlofs")
                usr<<output("<font color=purple> Oh mighty Special Coder, you were infected by the bug automatically!")
                usr.Thiswillhappen=0
            if(M&&!M.Thiswillhappen)
                M<<output("<font color=red>You feel strange, like a sudden change in your temperature.")
                HealingPower.Healing_Touchs()
            else if(M&&M.Thiswillhappen)
                if(prob(chance))
                    M<<output("<font color=red>You feel strange, like a sudden change in your temperature.")
                    HealingPower.Healing_Touchs()
                else
                    return 0
            else if(!M)
                return 0


Problem description:

Causes a run-time, can't execute null.key, can you provide me with a better way to program this code?
Sep 21 2013, 8:44 am
Best response
You need to test that M is not null first:

if(M&&M.key=="Adlofs")
Sep 21 2013, 9:39 am
I already tried that, it's still equal to null.
Sep 21 2013, 12:30 pm
1. Is this a verb? Can you provide the whole defined path?
2. You don't need to preface datums with /datum when you define them. They can simply be /CoderWorks.
3. You should check that M exists at the top of the procedure, not for if statement.
4. You don't need "as mob", the path is already declared as a mob.
Sep 21 2013, 12:37 pm
The if(!M) should be at the top. Also the real issue is something is calling the proc with a null M as an argument.
Sep 21 2013, 1:07 pm
Ter13 had it right. Nothing in the proc is exactly wrong other than you aren't checking if M exists. The issue is what ever your doing is getting a null M.
Sep 21 2013, 2:40 pm (Edited on Sep 21 2013, 2:51 pm)
Try using M.client.ckey, rather than Key.. I know it's not going to fix any problems, but the client is always there, at least I would assume.

But with that, of course, comes the need for
if(M && M.client && M.client.ckey)
Which should check everything.