As segwit is active on testnet, blocks will only be downloaded from NODE_WITNESS peers. Though, exactly those peers are disconnected after `BLOCK_STALLING_TIMEOUT = 2` seconds. I am running master (6e6ab2c)

This behavior is consistent across restarts. Sample [debug.log](http://pastebin.ubuntu.com/23058327/) and [getchaintips](http://pastebin.ubuntu.com/23058325/).

It is possible that I shot my own foot at some point, but it seemed smelly enough to create an issue.

map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
    if (it == mapNodeState.end())
        return NULL;
    return &it->second;
}
int GetHeight()
{
    LOCK(cs_main);
    return chainActive.Height();
}
void UpdatePreferredDownload(CNode* node, CNodeState* state)
{
    nPreferredDownload -= state->fPreferredDownload;
    
    state->fPreferredDownload = (!node->fInbound || node->fWhitelisted) && !node->fOneShot && !node->fClient;
    nPreferredDownload += state->fPreferredDownload;
}
void InitializeNode(NodeId nodeid, const CNode *pnode) {