[rpc] walletcreatefundedpsbt: don't automatically append inputs

When the user doesn't specificy inputs, it makes sense to automatically select them. But when the user does specify inputs, we now fail if the amount is insufficient, unless addInputs is set to true.

4 files changed, 24 insertions, 7 deletions

diff --git a/src/wallet/coincontrol.cpp b/src/wallet/coincontrol.cpp
index c83e59882..720877ead 100644
--- a/src/wallet/coincontrol.cpp
+++ b/src/wallet/coincontrol.cpp
@@ -10,6 +10,7 @@ void CCoinControl::SetNull()
 {
     destChange = CNoDestination();
     m_change_type.reset();
+    m_add_inputs = true;
     fAllowOtherInputs = false;
     fAllowWatchOnly = false;
     m_avoid_partial_spends = gArgs.GetBoolArg("-avoidpartialspends", DEFAULT_AVOIDPARTIALSPENDS);
@@ -23,4 +24,3 @@ void CCoinControl::SetNull()
     m_min_depth = DEFAULT_MIN_DEPTH;
     m_max_depth = DEFAULT_MAX_DEPTH;
 }
-
diff --git a/src/wallet/coincontrol.h b/src/wallet/coincontrol.h
index 2893d0ab3..c499b0ff2 100644
--- a/src/wallet/coincontrol.h
+++ b/src/wallet/coincontrol.h
@@ -26,6 +26,8 @@ public:
     CTxDestination destChange;
     //! Override the default change type if set, ignored if destChange is set
     Optional<OutputType> m_change_type;
+    //! If false, only selected inputs are used
+    bool m_add_inputs;
     //! If false, allows unselected inputs, but requires all selected inputs be used
     bool fAllowOtherInputs;
     //! Includes watch only addresses which are solvable
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 24df94740..80328e0b8 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3016,13 +3016,12 @@ static UniValue listunspent(const JSONRPCRequest& request)
     return results;
 }
 
-void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& fee_out, int& change_position, UniValue options)
+void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& fee_out, int& change_position, UniValue options, CCoinControl& coinControl)
 {
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    CCoinControl coinControl;
     change_position = -1;
     bool lockUnspents = false;
     UniValue subtractFeeFromOutputs;
@@ -3037,6 +3036,7 @@ void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& f
         RPCTypeCheckArgument(options, UniValue::VOBJ);
         RPCTypeCheckObj(options,
             {
+                {"add_inputs", UniValueType(UniValue::VBOOL)},
                 {"changeAddress", UniValueType(UniValue::VSTR)},
                 {"changePosition", UniValueType(UniValue::VNUM)},
                 {"change_type", UniValueType(UniValue::VSTR)},
@@ -3050,6 +3050,10 @@ void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& f
             },
             true, true);
 
+        if (options.exists("add_inputs") ) {
+            coinControl.m_add_inputs = options["add_inputs"].get_bool();
+        }
+
         if (options.exists("changeAddress")) {
             CTxDestination dest = DecodeDestination(options["changeAddress"].get_str());
 
@@ -3224,7 +3228,8 @@ static UniValue fundrawtransaction(const JSONRPCRequest& request)
 
     CAmount fee;
     int change_position;
-    FundTransaction(pwallet, tx, fee, change_position, request.params[1]);
+    CCoinControl coin_control;
+    FundTransaction(pwallet, tx, fee, change_position, request.params[1], coin_control);
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("hex", EncodeHexTx(CTransaction(tx)));
@@ -4146,10 +4151,10 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
     }
 
             RPCHelpMan{"walletcreatefundedpsbt",
-                "\nCreates and funds a transaction in the Partially Signed Transaction format. Inputs will be added if supplied inputs are not enough\n"
+                "\nCreates and funds a transaction in the Partially Signed Transaction format.\n"
                 "Implements the Creator and Updater roles.\n",
                 {
-                    {"inputs", RPCArg::Type::ARR, RPCArg::Optional::NO, "The inputs",
+                    {"inputs", RPCArg::Type::ARR, RPCArg::Optional::NO, "The inputs. Leave empty to add inputs automatically. See add_inputs option.",
                         {
                             {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                 {
@@ -4180,6 +4185,7 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
                     {"locktime", RPCArg::Type::NUM, /* default */ "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
                     {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                         {
+                            {"add_inputs", RPCArg::Type::BOOL, /* default */ "false", "If inputs are specified, automatically include more if they are not enough."},
                             {"changeAddress", RPCArg::Type::STR_HEX, /* default */ "pool address", "The bitcoin address to receive the change"},
                             {"changePosition", RPCArg::Type::NUM, /* default */ "random", "The index of the change output"},
                             {"change_type", RPCArg::Type::STR, /* default */ "set by -changetype", "The output type to use. Only valid if changeAddress is not specified. Options are \"legacy\", \"p2sh-segwit\", and \"bech32\"."},
@@ -4237,7 +4243,11 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
         rbf = replaceable_arg.isTrue();
     }
     CMutableTransaction rawTx = ConstructTransaction(request.params[0], request.params[1], request.params[2], rbf);
-    FundTransaction(pwallet, rawTx, fee, change_position, request.params[3]);
+    CCoinControl coin_control;
+    // Automatically select coins, unless at least one is manually selected. Can
+    // be overriden by options.add_inputs.
+    coin_control.m_add_inputs = rawTx.vin.size() == 0;
+    FundTransaction(pwallet, rawTx, fee, change_position, request.params[3], coin_control);
 
     // Make a blank psbt
     PartiallySignedTransaction psbtx(rawTx);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 79e29d050..62b200500 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2149,6 +2149,11 @@ void CWallet::AvailableCoins(interfaces::Chain::Lock& locked_chain, std::vector<
         }
 
         for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
+            // Only consider selected coins if add_inputs is false
+            if (coinControl && !coinControl->m_add_inputs && !coinControl->IsSelected(COutPoint(entry.first, i))) {
+                continue;
+            }
+
             if (wtx.tx->vout[i].nValue < nMinimumAmount || wtx.tx->vout[i].nValue > nMaximumAmount)
                 continue;