Infinite loop and RAM exhaustion when attempting to split vehicle

[olanti-p]

Describe the bug

Infinite loop with RAM exhaustion happens when attempting to split vehicle.

Steps To Reproduce

1. Have a task manager or a debugger on standby to quickly stop the process
2. Load the attached save: cbn-stack-exhaust-veh-split.zip OR do step 3
3. Spawn a car, wield a crowbar, give yourself 200 strength and stand on the car's right side in the middle
4. Keep smashing to the left until the car splits into 2
5. Instead of splitting, the game will hang and RAM usage will skyrocket

Screenshots

No response

Versions and configuration

Game version eb8ffb2

Additional context

Related: #2250.

Found while testing #3550, but is not affected by that PR.

LLDB backtrace when the game was paused while in the loop

frame #0: 0x00007ffff79e6cca libc.so.6`__memcpy_avx_unaligned_erms at memmove-vec-unaligned-erms.S:708
frame #1: 0x0000555556455535 cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] item** std::__copy_move<true, true, std::random_access_iterator_tag>::__copy_m<item*>(__first=<unavailable>, __last=<unavailable>, __result=0x00005555e74831a0) at stl_algobase.h:431:6
frame #2: 0x000055555645552a cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] item** std::__copy_move_a2<true, item**, item**>(__first=<unavailable>, __last=<unavailable>, __result=0x00005555e74831a0) at stl_algobase.h:494:14
frame #3: 0x000055555645552a cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] item** std::__copy_move_a1<true, item**, item**>(__first=<unavailable>, __last=<unavailable>, __result=0x00005555e74831a0) at stl_algobase.h:522:14
frame #4: 0x000055555645552a cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] __gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>> std::__copy_move_a<true, __gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>>, __gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>>>(__first=<unavailable>, __last=<unavailable>, __result=__normal_iterator<item **, std::vector<item *, std::allocator<item *> > > @ scalar) at stl_algobase.h:530:3
frame #5: 0x000055555645552a cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] __gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>> std::move<__gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>>, __gnu_cxx::__normal_iterator<item**, std::vector<item*, std::allocator<item*>>>>(__first=<unavailable>, __last=<unavailable>, __result=__normal_iterator<item **, std::vector<item *, std::allocator<item *> > > @ scalar) at stl_algobase.h:652:14
frame #6: 0x000055555645552a cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] std::vector<item*, std::allocator<item*>>::_M_erase(this=<unavailable>, __position=std::vector<item *, std::allocator<item *> >::iterator @ scalar) at vector.tcc:175:2
frame #7: 0x000055555645551c cataclysm-tiles`location_vector<item>::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] std::vector<item*, std::allocator<item*>>::erase(this=<unavailable>, __position=std::vector<item *, std::allocator<item *> >::const_iterator @ scalar) at stl_vector.h:1431:16
frame #8: 0x000055555645551c cataclysm-tiles`location_vector<item>::erase(this=0x000055556b2f5090, it=<unavailable>, out=0x0000000000000000) at location_vector.cpp:304:56
frame #9: 0x0000555556b6ced3 cataclysm-tiles`vehicle_stack::erase(location_vector<item>::const_iterator, detached_ptr<item>*) [inlined] vehicle::remove_item(this=0x000055556b1d6dd0, part=<unavailable>, it=item_stack::const_iterator @ 0x00007fffffffcf90, ret=<unavailable>) at vehicle.cpp:5507:54
frame #10: 0x0000555556b6ce86 cataclysm-tiles`vehicle_stack::erase(this=0x00007fffffffd000, it=item_stack::const_iterator @ 0x00007fffffffd028, out=0x0000000000000000) at vehicle.cpp:235:22
frame #11: 0x0000555556b816e2 cataclysm-tiles`vehicle::part_removal_cleanup(this=0x000055556b1d6dd0) at vehicle.cpp:1970:23
frame #12: 0x00005555564b6f6e cataclysm-tiles`map::vehmove(this=0x0000555558124e10) at map.cpp:507:19
frame #13: 0x00005555560a4d59 cataclysm-tiles`game::do_turn(this=0x000055555762e780) at game.cpp:1502:7
frame #14: 0x0000555556c8c93c cataclysm-tiles`main(argc=<unavailable>, argv=<unavailable>) at main.cpp:766:20
frame #15: 0x00007ffff786fd90 libc.so.6`__libc_start_call_main(main=(cataclysm-tiles`main at main.cpp:191), argc=1, argv=0x00007fffffffda88) at libc_start_call_main.h:58:16
frame #16: 0x00007ffff786fe40 libc.so.6`__libc_start_main_impl(main=(cataclysm-tiles`main at main.cpp:191), argc=1, argv=0x00007fffffffda88, init=<unavailable>, fini=<unavailable>, rtld_fini=<unavailable>, stack_end=0x00007fffffffda78) at libc-start.c:392:3
frame #17: 0x00005555557ba9e5 cataclysm-tiles`_start + 37

[olanti-p]

Looks like when the vehicle parts are erased by it = parts.erase( it ) here

Cataclysm-BN/src/vehicle.cpp

Lines 1966 to 1979 in d82fd66

	for( std::vector<vehicle_part>::iterator it = parts.begin(); it != parts.end(); /* noop */ ) {
	if( it->removed ) {
	auto items = get_items( std::distance( parts.begin(), it ) );
	while( !items.empty() ) {
	items.erase( items.begin() );
	}
	const tripoint &pt = global_part_pos3( *it );
	here.clear_vehicle_point_from_cache( this, pt );
	it = parts.erase( it );
	changed = true;
	} else {
	++it;
	}
	}

parts, which is of type std::vector<vehicle_part>, reallocates the vehicle parts by copying them like this:

Cataclysm-BN/src/vehicle_part.cpp

Lines 109 to 117 in d82fd66

	vehicle_part &vehicle_part::operator=( const vehicle_part &source )
	{
	copy_static_from( source );
	base = item::spawn( *source.base );
	for( item * const &it : source.items ) {
	items.push_back( item::spawn( *it ) );
	}
	return *this;
	}

Which ends up spawning extra items.