Interactive Stacked Sector Portals - Crash to Desktop

[Dragonfly]

Hello. I've spoken to Rachael in a private message via Discord regarding this issue who requested I post about this issue here.

I've been making a map which has caused a crash to desktop. It is reproducible, but not entirely reliably.



Rachael asked me to PM the map to both _mental_ and Graf - so shortly after this post being submitted I will PM you two with the report and the offending map. The player start has been moved to the area which causes the crash.

I can't reliably recreate the crash but it happens "While fighting the boss" in this map. Seemingly at random, although I suspected it was to do with the projectiles passing through the portal. Rachael said "you're right it's a portal issue, it's crashing at a portal transfer, but I think it has to do with the map setup (and possibly an error thereof) - note that the crash is triggered by firing the plasma gun above the level structures".

If you could please advise of the error I would be very appreciative. Thank you!

[Rachael]

This is the information I was able to gather from the crash: (simply aim the plasma gun up above the level structures and fire from the ground to get a similar crash, it's a bit tricky to get it to happen but I suspect there's a hole in the map's portal group that's responsible for making it happen)


Crash is on g_levellocals.h line 231

Stack trace:

Code: Select all

>	gzdoom.exe!sector_t::GetOppositePortalGroup(int plane) Line 231	C++
 	gzdoom.exe!P_TryMove(AActor * thing, const TVector2<double> & pos, int dropoff, const secplane_t * onfloor, FCheckPosition & tm, bool missileCheck) Line 2710	C++
 	gzdoom.exe!P_XYMovement(AActor * mo, TVector2<double> scroll) Line 2534	C++
 	gzdoom.exe!AActor::Tick() Line 4468	C++
 	gzdoom.exe!AF_DThinker_Tick(VMValue * param, TArray<VMValue,VMValue> & defaultparam, int numparam, VMReturn * ret, int numret) Line 653	C++
 	gzdoom.exe!VMCall(VMFunction * func, VMValue * params, int numparams, VMReturn * results, int numresults) Line 438	C++
 	gzdoom.exe!DThinker::CallTick() Line 662	C++
 	gzdoom.exe!DThinker::TickThinkers(FThinkerList * list, FThinkerList * dest) Line 580	C++
 	gzdoom.exe!DThinker::RunThinkers() Line 499	C++
 	gzdoom.exe!P_Ticker() Line 149	C++
 	gzdoom.exe!G_Ticker() Line 1229	C++
 	gzdoom.exe!TryRunTics() Line 1953	C++
 	gzdoom.exe!D_DoomLoop() Line 1067	C++
 	gzdoom.exe!D_DoomMain() Line 2760	C++
 	gzdoom.exe!DoMain(HINSTANCE__ * hInstance) Line 1042	C++
 	gzdoom.exe!WinMain(HINSTANCE__ * hInstance, HINSTANCE__ * nothing, char * cmdline, int nCmdShow) Line 1359	C++
 	gzdoom.exe!invoke_main() Line 99	C++
 	gzdoom.exe!__scrt_common_main_seh() Line 253	C++
 	gzdoom.exe!__scrt_common_main() Line 296	C++
 	gzdoom.exe!WinMainCRTStartup() Line 17	C++
 	kernel32.dll!00007ffcb62c1fe4()	Unknown
 	ntdll.dll!00007ffcb720ef91()	Unknown

Active variables:

Code: Select all

+		Portals	0x000002425a1111f0 {0, 0}	unsigned int[2]
		Portals[plane]	0	unsigned int
+		level	{md5=0x00007ff7c51b15c0 "¡Ùùsv\aìar ý|\v~R¡... time=7068 maptime=7068 ...}	FLevelLocals
+		level.sectorPortals	{Array=0x000002424e24bc50 {mType=0 mFlags=1 mPartner=0 ...} Count=7 Most=16 }	TArray<FSectorPortal,FSectorPortal>
		plane	1	int
+		this	0x000002425a110fb0 {planes=0x000002425a110fb0 {{xform={xOffs=0.00000000000000000 yOffs=0.00000000000000000 ...} ...}, ...} ...}	sector_t *

I am not entirely sure I can fix this one on my own. If any more information is needed I can try and make it crash again.

[Graf Zahl]

You will have to wait a bit. I got hit by the flu and won't be able to do much checking over the next few days.

[Rachael]

I got hit by the flu and won't be able to do much checking over the next few days.

Oh no! Get better soon, Graf!

[_mental_]

It's the same issue as this one. There is a pull request that fixes the crash.
Unfortunately I still have no idea is it correct or not. For this report I can give exact steps to reproduce with a screenshot if needed.

[Graf Zahl]

I originally wanted to check the PRs this weekend, now that Timidity is nearly done. Well, bad luck, it'll probably have to wait for another week.

[Dragonfly]

@Graf - get better soon! I'm on the 'recovering half' of a flu myself, nasty stuff.

@_mental_ if you could please demonstrate the cause of the crash for me I would be very thankful. Also, what will happen if this error occurs again in future versions of GZDoom what will happen?, I assume 'nothing, the game will carry on as normal'.

Thanks guys; I really appreciate all the hours you've put into making (G)ZDoom a brilliant engine to mod for.

[_mental_]

if you could please demonstrate the cause of the crash for me I would be very thankful.

Replied in PM with my steps to reproduce.

Also, what will happen if this error occurs again in future versions of GZDoom what will happen?, I assume 'nothing, the game will carry on as normal'.

When this will be fixed the game won't crash. Projectiles should behave the same independently from presence of portals.

[Dragonfly]

Thank you _mental_ for the pm, makes sense to me. To fix this for 3.2.5 users I've simply made the portal visual. Since the ceiling of the power portal is sky the projectiles gracefully vanish instead of causing a major crash, heh.

I appreciate all the help; good luck working on the fix for this issue.