Current bitcoin-master on testnet, `maxconnections=8` in the config file. Running in VM that doesn't have public IP and is not reachable from the Internet.

Wait until you have 8 peers.

```
telnet localhost 18333
```

It will result in:

```
Assertion failed: (nMaxInbound > 0), function AcceptConnection, file net.cpp, line 973.
```

First found in https://github.com/bitcoin/bitcoin/pull/8996, but can be reproduced on master.

DeleteNode(pnode);
    }
    vNodes.clear();
    vNodesDisconnected.clear();
    vhListenSocket.clear();
    delete semOutbound;
    semOutbound = NULL;
    if(pnodeLocalHost)
        DeleteNode(pnodeLocalHost);
    pnodeLocalHost = NULL;
}
void CConnman::DeleteNode(CNode* pnode)
{
    assert(pnode);
    bool fUpdateConnectionTime = false;
    GetNodeSignals().FinalizeNode(pnode->GetId(), fUpdateConnectionTime);
    if(fUpdateConnectionTime)
        addrman.Connected(pnode->addr);
    delete pnode;
}
CConnman::~CConnman()
{
    Stop();
}
size_t CConnman::GetAddressCount() const
{
    return addrman.size();
}
void CConnman::SetServices(const CService &addr, ServiceFlags nServices)