Merge #9222: Add 'subtractFeeFromAmount' option to 'fundrawtransaction'.

453bda6 Add 'subtractFeeFromOutputs' option to 'fundrawtransaction'. (Chris Moore)

1 files changed, 31 insertions, 7 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 82f8990562..2428ef04e2 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2479,7 +2479,8 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
         throw runtime_error(
                             "fundrawtransaction \"hexstring\" ( options )\n"
                             "\nAdd inputs to a transaction until it has enough in value to meet its out value.\n"
-                            "This will not modify existing inputs, and will add one change output to the outputs.\n"
+                            "This will not modify existing inputs, and will add at most one change output to the outputs.\n"
+                            "No existing outputs will be modified unless \"subtractFeeFromOutputs\" is specified.\n"
                             "Note that inputs which were signed may need to be resigned after completion since in/outputs have been added.\n"
                             "The inputs added will not be signed, use signrawtransaction for that.\n"
                             "Note that all existing inputs must have their previous output transaction be in the wallet.\n"
@@ -2491,11 +2492,17 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
                             "1. \"hexstring\"           (string, required) The hex string of the raw transaction\n"
                             "2. options                 (object, optional)\n"
                             "   {\n"
-                            "     \"changeAddress\"     (string, optional, default pool address) The bitcoin address to receive the change\n"
-                            "     \"changePosition\"    (numeric, optional, default random) The index of the change output\n"
-                            "     \"includeWatching\"   (boolean, optional, default false) Also select inputs which are watch only\n"
-                            "     \"lockUnspents\"      (boolean, optional, default false) Lock selected unspent outputs\n"
-                            "     \"feeRate\"           (numeric, optional, default not set: makes wallet determine the fee) Set a specific feerate (" + CURRENCY_UNIT + " per KB)\n"
+                            "     \"changeAddress\"          (string, optional, default pool address) The bitcoin address to receive the change\n"
+                            "     \"changePosition\"         (numeric, optional, default random) The index of the change output\n"
+                            "     \"includeWatching\"        (boolean, optional, default false) Also select inputs which are watch only\n"
+                            "     \"lockUnspents\"           (boolean, optional, default false) Lock selected unspent outputs\n"
+                            "     \"feeRate\"                (numeric, optional, default not set: makes wallet determine the fee) Set a specific feerate (" + CURRENCY_UNIT + " per KB)\n"
+                            "     \"subtractFeeFromOutputs\" (array, optional) A json array of integers.\n"
+                            "                              The fee will be equally deducted from the amount of each specified output.\n"
+                            "                              The outputs are specified by their zero-based index, before any change output is added.\n"
+                            "                              Those recipients will receive less bitcoins than you enter in their corresponding amount field.\n"
+                            "                              If no outputs are specified here, the sender pays the fee.\n"
+                            "                                  [vout_index,...]\n"
                             "   }\n"
                             "                         for backward compatibility: passing in a true instead of an object will result in {\"includeWatching\":true}\n"
                             "\nResult:\n"
@@ -2523,6 +2530,8 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
     bool lockUnspents = false;
     CFeeRate feeRate = CFeeRate(0);
     bool overrideEstimatedFeerate = false;
+    UniValue subtractFeeFromOutputs;
+    set<int> setSubtractFeeFromOutputs;
 
     if (request.params.size() > 1) {
       if (request.params[1].type() == UniValue::VBOOL) {
@@ -2541,6 +2550,7 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
                 {"includeWatching", UniValueType(UniValue::VBOOL)},
                 {"lockUnspents", UniValueType(UniValue::VBOOL)},
                 {"feeRate", UniValueType()}, // will be checked below
+                {"subtractFeeFromOutputs", UniValueType(UniValue::VARR)},
             },
             true, true);
 
@@ -2567,6 +2577,9 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
             feeRate = CFeeRate(AmountFromValue(options["feeRate"]));
             overrideEstimatedFeerate = true;
         }
+
+        if (options.exists("subtractFeeFromOutputs"))
+            subtractFeeFromOutputs = options["subtractFeeFromOutputs"].get_array();
       }
     }
 
@@ -2581,10 +2594,21 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
     if (changePosition != -1 && (changePosition < 0 || (unsigned int)changePosition > tx.vout.size()))
         throw JSONRPCError(RPC_INVALID_PARAMETER, "changePosition out of bounds");
 
+    for (unsigned int idx = 0; idx < subtractFeeFromOutputs.size(); idx++) {
+        int pos = subtractFeeFromOutputs[idx].get_int();
+        if (setSubtractFeeFromOutputs.count(pos))
+            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid parameter, duplicated position: %d", pos));
+        if (pos < 0)
+            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid parameter, negative position: %d", pos));
+        if (pos >= int(tx.vout.size()))
+            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid parameter, position too large: %d", pos));
+        setSubtractFeeFromOutputs.insert(pos);
+    }
+
     CAmount nFeeOut;
     string strFailReason;
 
-    if(!pwalletMain->FundTransaction(tx, nFeeOut, overrideEstimatedFeerate, feeRate, changePosition, strFailReason, includeWatching, lockUnspents, changeAddress))
+    if(!pwalletMain->FundTransaction(tx, nFeeOut, overrideEstimatedFeerate, feeRate, changePosition, strFailReason, includeWatching, lockUnspents, setSubtractFeeFromOutputs, changeAddress))
         throw JSONRPCError(RPC_INTERNAL_ERROR, strFailReason);
 
     UniValue result(UniValue::VOBJ);