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.

}
    else if (strCommand == NetMsgType::TX)
    {
        
        
        if (!fRelayTxes && (!pfrom->fWhitelisted || !GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)))
        {
            LogPrint("net", "transaction sent in violation of protocol peer=%d\n", pfrom->id);
            return true;
        }
        deque<COutPoint> vWorkQueue;
        vector<uint256> vEraseQueue;
        CTransaction tx;
        vRecv >> tx;
        CInv inv(MSG_TX, tx.GetHash());
        pfrom->AddInventoryKnown(inv);
        LOCK(cs_main);
        bool fMissingInputs = false;
        CValidationState state;
        pfrom->setAskFor.erase(inv.hash);
        mapAlreadyAskedFor.erase(inv.hash);
        if (!AlreadyHave(inv) && AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs)) {
            mempool.check(pcoinsTip);
            RelayTransaction(tx);
            for (unsigned int i = 0; i < tx.vout.size(); i++) {
                vWorkQueue.emplace_back(inv.hash, i);
            }
            pfrom->nLastTXTime = GetTime();
            LogPrint("mempool", "AcceptToMemoryPool: peer=%d: accepted %s (poolsz %u txn, %u kB)\n",
                pfrom->id,