Add -respendnotify option and new RPC data

-respendnotify=<cmd> Execute command when a network tx respends wallet
tx input (%s=respend TxID, %t=wallet TxID)

Add respendsobserved array to gettransaction, listtransactions, and
listsinceblock RPCs.  This omits the malleated clones that are included
in the walletconflicts array.

Add RPC help for respendsobserved and walletconflicts (help was missing
for the latter).

contrib/debian/manpages/bitcoin-qt.1

@@ -139,6 +139,9 @@ Execute command when the best block changes (%s in cmd is replaced by block hash
 \fB\-walletnotify=\fR<cmd>
 Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)
 .TP
+\fB\-respendnotify=\fR<cmd>
+Execute command when a network tx respends wallet tx input (%s=respend TxID, %t=wallet TxID)
+.TP
 \fB\-alertnotify=\fR<cmd>
 Execute command when a relevant alert is received (%s in cmd is replaced by message)
 .TP

src/init.cpp

@@ -260,6 +260,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += "  -upgradewallet         " + _("Upgrade wallet to latest format") + " " + _("on startup") + "\n";
     strUsage += "  -wallet=<file>         " + _("Specify wallet file (within data directory)") + " " + _("(default: wallet.dat)") + "\n";
     strUsage += "  -walletnotify=<cmd>    " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n";
+    strUsage += "  -respendnotify=<cmd>   " + _("Execute command when a network tx respends wallet tx input (%s=respend TxID, %t=wallet TxID)") + "\n";
     strUsage += "  -zapwallettxes=<mode>  " + _("Delete all wallet transactions and only recover those part of the blockchain through -rescan on startup") + "\n";
     strUsage += "                         " + _("(default: 1, 1 = keep tx meta data e.g. account owner and payment request information, 2 = drop tx meta data)") + "\n";
 #endif

src/rpcwallet.cpp

@@ -58,6 +58,10 @@ void WalletTxToJSON(const CWalletTx& wtx, Object& entry)
     BOOST_FOREACH(const uint256& conflict, wtx.GetConflicts())
         conflicts.push_back(conflict.GetHex());
     entry.push_back(Pair("walletconflicts", conflicts));
+    Array respends;
+    BOOST_FOREACH(const uint256& respend, wtx.GetConflicts(false))
+        respends.push_back(respend.GetHex());
+    entry.push_back(Pair("respendsobserved", respends));
     entry.push_back(Pair("time", wtx.GetTxTime()));
     entry.push_back(Pair("timereceived", (int64_t)wtx.nTimeReceived));
     BOOST_FOREACH(const PAIRTYPE(string,string)& item, wtx.mapValue)
@@ -1211,6 +1215,12 @@ Value listtransactions(const Array& params, bool fHelp)
             "    \"blockindex\": n,          (numeric) The block index containing the transaction. Available for 'send' and 'receive'\n"
             "                                          category of transactions.\n"
             "    \"txid\": \"transactionid\", (string) The transaction id. Available for 'send' and 'receive' category of transactions.\n"
+            "    \"walletconflicts\" : [\n"
+            "        \"conflictid\",  (string) Ids of transactions, including equivalent clones, that re-spend a txid input.\n"
+            "    ],\n"
+            "    \"respendsobserved\" : [\n"
+            "        \"respendid\",  (string) Ids of transactions, NOT equivalent clones, that re-spend a txid input. \"Double-spends.\"\n"
+            "    ],\n"
             "    \"time\": xxx,              (numeric) The transaction time in seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in seconds since epoch (midnight Jan 1 1970 GMT). Available \n"
             "                                          for 'send' and 'receive' category of transactions.\n"
@@ -1376,6 +1386,12 @@ Value listsinceblock(const Array& params, bool fHelp)
             "    \"blockindex\": n,          (numeric) The block index containing the transaction. Available for 'send' and 'receive' category of transactions.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\",  (string) The transaction id. Available for 'send' and 'receive' category of transactions.\n"
+            "    \"walletconflicts\" : [\n"
+            "        \"conflictid\",  (string) Ids of transactions, including equivalent clones, that re-spend a txid input.\n"
+            "    ],\n"
+            "    \"respendsobserved\" : [\n"
+            "        \"respendid\",  (string) Ids of transactions, NOT equivalent clones, that re-spend a txid input. \"Double-spends.\"\n"
+            "    ],\n"
             "    \"time\": xxx,              (numeric) The transaction time in seconds since epoch (Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in seconds since epoch (Jan 1 1970 GMT). Available for 'send' and 'receive' category of transactions.\n"
             "    \"comment\": \"...\",       (string) If a comment is associated with the transaction.\n"
@@ -1448,6 +1464,12 @@ Value gettransaction(const Array& params, bool fHelp)
             "  \"blockindex\" : xx,       (numeric) The block index\n"
             "  \"blocktime\" : ttt,       (numeric) The time in seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"txid\" : \"transactionid\",   (string) The transaction id.\n"
+            "  \"walletconflicts\" : [\n"
+            "      \"conflictid\",  (string) Ids of transactions, including equivalent clones, that re-spend a txid input.\n"
+            "  ],\n"
+            "  \"respendsobserved\" : [\n"
+            "      \"respendid\",  (string) Ids of transactions, NOT equivalent clones, that re-spend a txid input. \"Double-spends.\"\n"
+            "  ],\n"
             "  \"time\" : ttt,            (numeric) The transaction time in seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"timereceived\" : ttt,    (numeric) The time received in seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"details\" : [\n"

src/wallet.cpp

@@ -600,6 +600,14 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFromLoadWallet)
                 if (IsFromMe(txConflict) || IsMine(txConflict))
                 {
                     NotifyTransactionChanged(this, conflictHash, CT_GOT_CONFLICT);  //Throws dialog
+                    // external respend notify
+                    std::string strCmd = GetArg("-respendnotify", "");
+                    if (!strCmd.empty())
+                    {
+                        boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
+                        boost::replace_all(strCmd, "%t", conflictHash.GetHex());
+                        boost::thread t(runCommand, strCmd); // thread runs free
+                    }
                 }
             }
         }