Crash if enemy sees player through 0 target Line_Portal

Bauul · Post by **Bauul** » Wed May 31, 2017 9:11 pm

I was having a lot of issues with hard crashes on a map that used Line_Portals, and I think I've worked out why:

If a map contains a Line_Portal (Type 156) that has the exit line tag set to "0" (which is useful if you want to turn the portal on later, as you can't create portals at runtime) and an enemy sights you through it, it seems as though GZDoom crashes to desktop. Tested on 3.0.1

Attached is an example WAD. The Lost Soul sights the player as soon as the map launches, so the crash is almost instant. If you turn the Lost Soul to face away from the player, the crash only happens if you alert it and it faces you. Interesting from what I can tell if the enemy is alerted via sound, it doesn't crash straight away, it's specifically when they see you.

I've also attached a crash report, but hopefully it's easy enough to reproduce.

Bauul · Post by **Bauul** » Sat Jun 10, 2017 6:12 pm

Was anyone able to replicate this, or was it just my machine?

Post by **_mental_** » Sat Jun 10, 2017 11:04 pm

No, it's hardware independent issue. I can fix the crash but I'm not sure that the problem isn't on the higher level of portal handling logic.

Post by **Graf Zahl** » Sat Aug 12, 2017 4:52 am

There is no problem in the portal handling here. It was just a missing null pointer check.

ZDoom