// Sign
                int nIn = 0;
                BOOST_FOREACH(const PAIRTYPE(const CWalletTx*,unsigned int)& coin, setCoins)
                    if (!SignSignature(*this, *coin.first, wtxNew, nIn++))
                    {
                        strFailReason = _("Signing transaction failed");
                        return false;
                    }

bool SignSignature(const CKeyStore &keystore, const CScript& fromPubKey, CTransaction& txTo, unsigned int nIn, int nHashType)
{
    assert(nIn < txTo.vin.size());
    CTxIn& txin = txTo.vin[nIn];

    // Leave out the signature from the hash, since a signature can't sign itself.
    // The checksig op will also drop the signatures from its hash.
    uint256 hash = SignatureHash(fromPubKey, txTo, nIn, nHashType);

    txnouttype whichType;
    if (!Solver(keystore, fromPubKey, hash, nHashType, txin.scriptSig, whichType))
        return false;

    if (whichType == TX_SCRIPTHASH)
    {
        // Solver returns the subscript that need to be evaluated;
        // the final scriptSig is the signatures from that
        // and then the serialized subscript:
        CScript subscript = txin.scriptSig;

        // Recompute txn hash using subscript in place of scriptPubKey:
        uint256 hash2 = SignatureHash(subscript, txTo, nIn, nHashType);

        txnouttype subType;
        bool fSolved =
            Solver(keystore, subscript, hash2, nHashType, txin.scriptSig, subType) && subType != TX_SCRIPTHASH;
        // Append serialized subscript whether or not it is completely signed:
        txin.scriptSig << static_cast<valtype>(subscript);
        if (!fSolved) return false;
    }

    // Test solution
    return VerifyScript(txin.scriptSig, fromPubKey, txTo, nIn, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC, 0);
}

bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType)
{
    assert(nIn < txTo.vin.size());
    CTxIn& txin = txTo.vin[nIn];
    assert(txin.prevout.n < txFrom.vout.size());
    const CTxOut& txout = txFrom.vout[txin.prevout.n];

    return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, nHashType);
}