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.

remoteAddr = ", peeraddr=" + pfrom->addr.ToString();
        LogPrintf("receive version message: %s: version %d, blocks=%d, us=%s, peer=%d%s\n",
                  pfrom->cleanSubVer, pfrom->nVersion,
                  pfrom->nStartingHeight, addrMe.ToString(), pfrom->id,
                  remoteAddr);
        int64_t nTimeOffset = nTime - GetTime();
        pfrom->nTimeOffset = nTimeOffset;
        AddTimeData(pfrom->addr, nTimeOffset);
    }
    else if (pfrom->nVersion == 0)
    {
        
        LOCK(cs_main);
        Misbehaving(pfrom->GetId(), 1);
        return false;
    }
    else if (strCommand == NetMsgType::VERACK)
    {
        pfrom->SetRecvVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
        
        if (pfrom->fNetworkNode) {
            LOCK(cs_main);
            State(pfrom->GetId())->fCurrentlyConnected = true;
        }
        if (pfrom->nVersion >= SENDHEADERS_VERSION) {
            
            
            
            
            pfrom->PushMessage(NetMsgType::SENDHEADERS);