[wallet] Refactor to use new MIN_CHANGE

* Introduce new constant MIN_CHANGE and use it instead of the
hardcoded "CENT"
* Add test case for MIN_CHANGE
* Introduce new constant for -mintxfee default:
  DEFAULT_TRANSACTION_MINFEE = 1000

1 files changed, 11 insertions, 0 deletions

diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index bd30b67b09..143ca22bdc 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -41,8 +41,12 @@ extern bool fPayAtLeastCustomFee;
 static const CAmount DEFAULT_TRANSACTION_FEE = 0;
 //! -paytxfee will warn if called with a higher fee than this amount (in satoshis) per KB
 static const CAmount nHighTransactionFeeWarning = 0.01 * COIN;
+//! -mintxfee default
+static const CAmount DEFAULT_TRANSACTION_MINFEE = 1000;
 //! -maxtxfee default
 static const CAmount DEFAULT_TRANSACTION_MAXFEE = 0.1 * COIN;
+//! minimum change amount
+static const CAmount MIN_CHANGE = CENT;
 //! -txconfirmtarget default
 static const unsigned int DEFAULT_TX_CONFIRM_TARGET = 2;
 //! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
@@ -544,7 +548,14 @@ public:
     //! check whether we are allowed to upgrade (or already support) to the named feature
     bool CanSupportFeature(enum WalletFeature wf) { AssertLockHeld(cs_wallet); return nWalletMaxVersion >= wf; }
 
+    /**
+     * populate vCoins with vector of available COutputs.
+     */
     void AvailableCoins(std::vector<COutput>& vCoins, bool fOnlyConfirmed=true, const CCoinControl *coinControl = NULL, bool fIncludeZeroValue=false) const;
+    /**
+     * Select coins until nTargetValue is reached. Return the actual value
+     * and the corresponding coin set.
+     */
     bool SelectCoinsMinConf(const CAmount& nTargetValue, int nConfMine, int nConfTheirs, std::vector<COutput> vCoins, std::set<std::pair<const CWalletTx*,unsigned int> >& setCoinsRet, CAmount& nValueRet) const;
 
     bool IsSpent(const uint256& hash, unsigned int n) const;