Teleporting NPCs directly after dimension-shifting crashes the game

[Standing-Storm]

Describe the bug

While working on #83451, I managed to get basically everything working except that sometimes I had a crash when teleporting. On experimentation, it seems that it's bringing an NPC along that causes problems--going alone (dimension-shift -> teleport) causes no problems.

Attach save file

Sky Island-trimmed.tar.gz

Steps to reproduce

1. Talk to the obelisk
2. Select Quick Expedition -> Target field
3. Game crashes

You will need the JSON changes in #83451 to reproduce the error

Expected behavior

Game does not crash

Screenshots

No response

Versions and configuration

• OS: Windows
  • OS Version: 10.0.26100.6899 (24H2)
• Game Version: cdda-experimental-2025-10-22-1656 [64-bit]
• Graphics Version: Tiles
• Game Language: System language []
• Mods loaded: [
  Dark Days Ahead [dda],
  Disable NPC Needs [no_npc_food],
  Portal Storms Ignore NPCs [personal_portal_storms],
  Sky Island [skyisland]
  ]

Additional context

@Blueflowerss mentioned that it's due to teleporting an NPC immediately after dimension-hopping, and if so, I could just force a short activity to pass time, but that wouldn't fix the bug.

crash.log
debug.log

[ehughsbaird]

This is quite an interesting bug: It stops reproducing if you turn off the compass sidebar element.

It crashes here, on the call to get_attitude, when n seems to be a valid pointer (it is at least not null, the underlying memory may not be there):

Cataclysm-DDA/src/display.cpp

Lines 1312 to 1324 in cf29719

	for( npc *n : mon_visible.unique_types[d] ) {
	switch( n->get_attitude() ) {
	case NPCATT_KILL:
	syms.emplace_back( "@", c_red );
	break;
	case NPCATT_FOLLOW:
	syms.emplace_back( "@", c_light_green );
	break;
	default:
	syms.emplace_back( "@", c_pink );
	break;
	}
	}

And get_attitude is the following.

Cataclysm-DDA/src/npc.cpp

Lines 3747 to 3750 in cf29719

	npc_attitude npc::get_attitude() const
	{
	return attitude;
	}

[Light-Wave]

There is a function that seems to update mon_visible here

Cataclysm-DDA/src/game.cpp

Line 3744 in cf29719

void game::mon_info_update( )

Perhaps calling it before you return true at the end of travel_to_dimension could help?

Cataclysm-DDA/src/game.cpp

Lines 10769 to 10771 in cf29719

	}
	return true;
	}

[ehughsbaird]

That is probably it. I won't be able to test that for a bit though.