Add option to avoid spending unconfirmed change

src/init.cpp

@@ -274,6 +274,7 @@ std::string HelpMessage(HelpMessageMode hmm)
     strUsage += "  -upgradewallet         " + _("Upgrade wallet to latest format") + "\n";
     strUsage += "  -wallet=<file>         " + _("Specify wallet file (within data directory)") + "\n";
     strUsage += "  -walletnotify=<cmd>    " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n";
+    strUsage += "  -spendzeroconfchange   " + _("Spend unconfirmed change when sending transactions (default: 1)") + "\n";
 #endif
     strUsage += "\n" + _("Block creation options:") + "\n";
     strUsage += "  -blockminsize=<n>      " + _("Set minimum block size in bytes (default: 0)") + "\n";
@@ -539,6 +540,7 @@ bool AppInit2(boost::thread_group& threadGroup)
         if (nTransactionFee > 0.25 * COIN)
             InitWarning(_("Warning: -paytxfee is set very high! This is the transaction fee you will pay if you send a transaction."));
     }
+    bSpendZeroConfChange = GetArg("-spendzeroconfchange", true);
 
     strWalletFile = GetArg("-wallet", "wallet.dat");
 #endif

src/wallet.cpp

@@ -18,6 +18,7 @@ using namespace std;
 
 // Settings
 int64_t nTransactionFee = 0;
+bool bSpendZeroConfChange = true;
 
 //////////////////////////////////////////////////////////////////////////////
 //
@@ -1192,7 +1193,7 @@ bool CWallet::SelectCoins(int64_t nTargetValue, set<pair<const CWalletTx*,unsign
 
     return (SelectCoinsMinConf(nTargetValue, 1, 6, vCoins, setCoinsRet, nValueRet) ||
             SelectCoinsMinConf(nTargetValue, 1, 1, vCoins, setCoinsRet, nValueRet) ||
-            SelectCoinsMinConf(nTargetValue, 0, 1, vCoins, setCoinsRet, nValueRet));
+            (bSpendZeroConfChange && SelectCoinsMinConf(nTargetValue, 0, 1, vCoins, setCoinsRet, nValueRet)));
 }
 
 

src/wallet.h

@@ -25,6 +25,7 @@
 
 // Settings
 extern int64_t nTransactionFee;
+extern bool bSpendZeroConfChange;
 
 class CAccountingEntry;
 class CCoinControl;