Some commands of `bitcoin-tx` accept an index of an existing input/output, e.g. `delin` or `delout`.  And while the index is checked for being out-of-bounds, garbage (non-numeral characters) are happily accepted.  All of the following are fine:

    $ bitcoin-tx -create outaddr=1:1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd delout=
    $ bitcoin-tx -create outaddr=1:1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd delout=foobar
    $ bitcoin-tx -create outaddr=1:1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd delout=0bla

I think all of them should throw an error instead of silently treating the index as zero.

The reason for this is that internally, `atoi` is called - and that by design discards anything after the first non-numeric character (and may just return zero if there are no numerals at all).

A possible fix would be to use `strtol` instead and to verify that the returned `endptr` is actually the end of the input string.  Alternatively, one could convert the integer back to a string and require that it matches the input string exactly.
if (scriptPubKey.size() > MAX_SCRIPT_SIZE) {
        throw std::runtime_error(strprintf(
                    "script exceeds size limit: %d > %d", scriptPubKey.size(), MAX_SCRIPT_SIZE));
    }
    if (bSegWit) {
        scriptPubKey = GetScriptForWitness(scriptPubKey);
    }
    if (bScriptHash) {
        if (scriptPubKey.size() > MAX_SCRIPT_ELEMENT_SIZE) {
            throw std::runtime_error(strprintf(
                        "redeemScript exceeds size limit: %d > %d", scriptPubKey.size(), MAX_SCRIPT_ELEMENT_SIZE));
        }
        scriptPubKey = GetScriptForDestination(CScriptID(scriptPubKey));
    }
    
    CTxOut txout(value, scriptPubKey);
    tx.vout.push_back(txout);
}
static void MutateTxDelInput(CMutableTransaction& tx, const std::string& strInIdx)
{
    
    int inIdx = atoi(strInIdx);
    if (inIdx < 0 || inIdx >= (int)tx.vin.size()) {
        std::string strErr = "Invalid TX input index '" + strInIdx + "'";
        throw std::runtime_error(strErr.c_str());
    }
    
    tx.vin.erase(tx.vin.begin() + inIdx);
}
static void MutateTxDelOutput(CMutableTransaction& tx, const std::string& strOutIdx)