Crash ContainerIterator::advance()

[Newone0]

Thread 2 (Thread 0x7ffff79d8700 (LWP 642687)):
#0  0x0000555555874a63 in ContainerIterator::advance() ()
No symbol table info available.
#1  0x00005555558b8c8a in Game::internalQuickLootCorpse(Player*, Container*) ()
No symbol table info available.
#2  0x00005555558b4b24 in Game::playerQuickLoot(unsigned int, Position const&, unsigned short, unsigned char, Item*) ()
No symbol table info available.
#3  0x0000555555892da2 in Dispatcher::threadMain() ()
No symbol table info available.
#4  0x00007ffff7d3dde4 in ?? () from /lib/x86_64-linux-gnu/libstdc++.so.6
No symbol table info available.
#5  0x00007ffff7fa6609 in start_thread (arg=<optimized out>) at pthread_create.c:477
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737347684096, 4238485523897402098, 140737488346334, 140737488346335, 140737488346336, 140737347682176, -4238503962232601870, -4238503162985037070}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = 0
#6  0x00007ffff7b79133 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

container.cpp:

void ContainerIterator::advance()
{
    if (Item* i = *cur) {
        if (Container* c = i->getContainer()) {
            if (!c->empty()) {
                over.push_back(c);
            }
        }
    }

    ++cur;

    if (cur == over.front()->itemlist.end()) {
        over.pop_front();
        if (!over.empty()) {
            cur = over.front()->itemlist.begin();
        }
    }
}

It is the same like in canary or tfs.
Any idea what happened?