When a pass of CreateTransaction fails to select enough bitcoin to meet the nFeeNeeded the next pass through may select a far smaller collection of inputs.  Currently it will continue to use the old fee amount based on the larger set of inputs, which can cause a non-trivial over-payment.

This may be the cause of the behavior reported here: https://www.reddit.com/r/Bitcoin/comments/5ltw5n/bitcoin_core_v0131_sends_enormously_high_fee/

Long ago fixing this was tricky due to a catch-22 between signing the transaction and knowing how much fee was required.  But after #9465 the whole algorithm will run using a dummy signature, so when there is already a change output fixing up the fee after finding a sufficient transaction should be a matter of a ~2 line change.

#ifndef BITCOIN_WALLET_WALLET_H
#define BITCOIN_WALLET_WALLET_H
#include "amount.h"
#include "streams.h"
#include "tinyformat.h"
#include "ui_interface.h"
#include "utilstrencodings.h"
#include "validationinterface.h"
#include "script/ismine.h"
#include "wallet/crypter.h"
#include "wallet/walletdb.h"
#include "wallet/rpcwallet.h"
#include <algorithm>
#include <atomic>
#include <map>
#include <set>
#include <stdexcept>
#include <stdint.h>
#include <string>
#include <utility>
#include <vector>