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.

(fAlreadyInFlight && blockInFlightIt->second.first == pfrom->GetId())) {
                list<QueuedBlock>::iterator *queuedBlockIt = NULL;
                if (!MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), chainparams.GetConsensus(), pindex, &queuedBlockIt)) {
                    if (!(*queuedBlockIt)->partialBlock)
                        (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&mempool));
                    else {
                        
                        LogPrint("net", "Peer sent us compact block we were already syncing!\n");
                        return true;
                    }
                }
                PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock;
                ReadStatus status = partialBlock.InitData(cmpctblock);
                if (status == READ_STATUS_INVALID) {
                    MarkBlockAsReceived(pindex->GetBlockHash()); 
                    Misbehaving(pfrom->GetId(), 100);
                    LogPrintf("Peer %d sent us invalid compact block\n", pfrom->id);
                    return true;
                } else if (status == READ_STATUS_FAILED) {
                    
                    std::vector<CInv> vInv(1);
                    vInv[0] = CInv(MSG_BLOCK, cmpctblock.header.GetHash());
                    pfrom->PushMessage(NetMsgType::GETDATA, vInv);
                    return true;
                }
                BlockTransactionsRequest req;
                for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
                    if (!partialBlock.IsTxAvailable(i))
                        req.indexes.push_back(i);
                }