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.
{
    
    int outIdx = atoi(strOutIdx);
    if (outIdx < 0 || outIdx >= (int)tx.vout.size()) {
        std::string strErr = "Invalid TX output index '" + strOutIdx + "'";
        throw std::runtime_error(strErr.c_str());
    }
    
    tx.vout.erase(tx.vout.begin() + outIdx);
}
static const unsigned int N_SIGHASH_OPTS = 6;
static const struct {
    const char *flagStr;
    int flags;
} sighashOptions[N_SIGHASH_OPTS] = {
    {"ALL", SIGHASH_ALL},
    {"NONE", SIGHASH_NONE},
    {"SINGLE", SIGHASH_SINGLE},
    {"ALL|ANYONECANPAY", SIGHASH_ALL|SIGHASH_ANYONECANPAY},
    {"NONE|ANYONECANPAY", SIGHASH_NONE|SIGHASH_ANYONECANPAY},
    {"SINGLE|ANYONECANPAY", SIGHASH_SINGLE|SIGHASH_ANYONECANPAY},
};
static bool findSighashFlags(int& flags, const std::string& flagStr)