I have an interesting problem with Qt Qlist container.
Trying to append QList to QList makes my iterator to point to unknown part of memory.

```
QList<int> listSmall;
QList<QList<int>> listBig;

for(int i = 0; i < 3; ++i)
    listSmall.append(i);

for(auto it = listSmall.begin(); it != listSmall.end(); ++it)
    listBig.append(listSmall);

```

Condition `it != listSmall.end();` always true if i append small list to big.
Why does this happen?

P.S. STL list works just fine.