A_Die address zero crash

[Apeirogon]

If world thing damaged/died event meet monster which call a_die() function, gzdoom crash with vm error "tried to read from address zero", if in such event dont provide check

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if (e.inflictor/damage source/target != null) {other actions}

before accessing inflictor/damage source/target actor.

[_mental_]

Please post a runnable sample.

Writing in your native language along with this “English” might help too.
I’m not a native speaker but it’s very hard for me to comprehend this report.

[Arctangent]

I'm pretty sure he's just running into the issue of not checking for null before trying to access something from an object.

[Graf Zahl]

I'm pretty sure...

That's the problem: We are just guessing.
Either we get a more usable description or this will get closed. I have no idea what he did.

[Apeirogon]

If monster die with null "target" pointer, and I try give something to killer of this monster, gzdoom crash.

[Graf Zahl]

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		if(ticks >= 150){owner.a_die(); self.destroy(); return;}

That's not correct. It has to be:

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		if(ticks >= 150){ if (owner != null) owner.a_die(); self.destroy(); return;}

If it crashes, that's a different matter.

[AFADoomer]

A crash is when the engine stops working and gives you an operating system error message. This is not a crash, it is a VM abort.

GZDoom is telling you that you told it to read from an object variable that has never been assigned a value. You must check for null values before referencing a pointer. That is how the engine works.

In addition to what Graf just posted, line 15 should probably check that e.Thing actually had a target before trying to give something to that target:

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if (e.Thing.Target) { e.Thing.Target.giveinventory("healthbonus", 1); }

If you don't do that, and the thing had no target (like if you use the 'kill monsters' cheat), then the engine will abort.