in v0.12 https://github.com/bitcoin/bitcoin/pull/7081 (by @luke-jr) was merged adding `-bytespersigop` (with default of 20).

this is preventing simple bare multisig transactions from being accepted into mempool when the size is < 400 bytes.  
eg; https://gist.github.com/rubensayshi/ac4f617207f7a50559e85d61c05800be

from 1-of-7 and onwards they are accepted because the ratio of bytes:sigops is high enough.  
also having 2 or more inputs will work because it again tips the ratio of bytes:sigops over.

the reason mainly being that `GetLegacySigOpCount` calls `GetSigOpCount` with `fAccurate=false`.

It looks like changing `GetLegacySigOpCount` to use `fAccurate=true` would cause side effects in the few other places (`ConnectBlock`, `CheckBlock`, `CreateNewBlock`) and simply adding `fAccurate` as arg to `GetLegacySigOpCount` would affect the value stored in `CTxMemPoolEntry.sigOpCount` which in turn affects a bunch of other things.

LOCK(cs_main);
    CNodeState &state = mapNodeState.insert(std::make_pair(nodeid, CNodeState())).first->second;
    state.name = pnode->addrName;
    state.address = pnode->addr;
}
void FinalizeNode(NodeId nodeid) {
    LOCK(cs_main);
    CNodeState *state = State(nodeid);
    if (state->fSyncStarted)
        nSyncStarted--;
    if (state->nMisbehavior == 0 && state->fCurrentlyConnected) {
        AddressCurrentlyConnected(state->address);
    }
    BOOST_FOREACH(const QueuedBlock& entry, state->vBlocksInFlight) {
        mapBlocksInFlight.erase(entry.hash);
    }
    EraseOrphansFor(nodeid);
    nPreferredDownload -= state->fPreferredDownload;
    nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
    assert(nPeersWithValidatedDownloads >= 0);
    mapNodeState.erase(nodeid);
    if (mapNodeState.empty()) {
        
        assert(mapBlocksInFlight.empty());
        assert(nPreferredDownload == 0);
        assert(nPeersWithValidatedDownloads == 0);
    }
}
bool MarkBlockAsReceived(const uint256& hash) {