wallet: limit v3 tx weight in coin selection

diff --git a/src/policy/truc_policy.h b/src/policy/truc_policy.h
index dbc77696..acd8ae56 100644
--- a/src/policy/truc_policy.h
+++ b/src/policy/truc_policy.h
@@ -28,8 +28,10 @@ static constexpr unsigned int TRUC_ANCESTOR_LIMIT{2};
 
 /** Maximum sigop-adjusted virtual size of all v3 transactions. */
 static constexpr int64_t TRUC_MAX_VSIZE{10000};
+static constexpr int64_t TRUC_MAX_WEIGHT{TRUC_MAX_VSIZE * WITNESS_SCALE_FACTOR};
 /** Maximum sigop-adjusted virtual size of a tx which spends from an unconfirmed TRUC transaction. */
 static constexpr int64_t TRUC_CHILD_MAX_VSIZE{1000};
+static constexpr int64_t TRUC_CHILD_MAX_WEIGHT{TRUC_CHILD_MAX_VSIZE * WITNESS_SCALE_FACTOR};
 // These limits are within the default ancestor/descendant limits.
 static_assert(TRUC_MAX_VSIZE + TRUC_CHILD_MAX_VSIZE <= DEFAULT_ANCESTOR_SIZE_LIMIT_KVB * 1000);
 static_assert(TRUC_MAX_VSIZE + TRUC_CHILD_MAX_VSIZE <= DEFAULT_DESCENDANT_SIZE_LIMIT_KVB * 1000);
diff --git a/src/wallet/coinselection.h b/src/wallet/coinselection.h
index 08889c8e..c86765c4 100644
--- a/src/wallet/coinselection.h
+++ b/src/wallet/coinselection.h
@@ -174,6 +174,8 @@ struct CoinSelectionParams {
      * 1) Received from other wallets, 2) replacing other txs, 3) that have been replaced.
      */
     bool m_include_unsafe_inputs = false;
+    /** The version of the transaction we are trying to create. */
+    uint32_t m_version{CTransaction::CURRENT_VERSION};
     /** The maximum weight for this transaction. */
     std::optional<int> m_max_tx_weight{std::nullopt};
 
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 8d120cc3..b643183e 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -8,6 +8,7 @@
 #include <key_io.h>
 #include <node/types.h>
 #include <policy/policy.h>
+#include <policy/truc_policy.h>
 #include <rpc/rawtransaction_util.h>
 #include <rpc/util.h>
 #include <script/script.h>
@@ -717,6 +718,12 @@ CreatedTransactionResult FundTransaction(CWallet& wallet, const CMutableTransact
         coinControl.m_max_tx_weight = options["max_tx_weight"].getInt<int>();
     }
 
+    if (tx.version == TRUC_VERSION) {
+        if (!coinControl.m_max_tx_weight.has_value() || coinControl.m_max_tx_weight.value() > TRUC_MAX_WEIGHT) {
+            coinControl.m_max_tx_weight = TRUC_MAX_WEIGHT;
+        }
+    }
+
     if (recipients.empty())
         throw JSONRPCError(RPC_INVALID_PARAMETER, "TX must have at least one output");
 
@@ -1316,6 +1323,7 @@ RPCHelpMan send()
             if (options.exists("max_tx_weight")) {
                 coin_control.m_max_tx_weight = options["max_tx_weight"].getInt<int>();
             }
+
             SetOptionsInputWeights(options["inputs"], options);
             // Clear tx.vout since it is not meant to be used now that we are passing outputs directly.
             // This sets us up for a future PR to completely remove tx from the function signature in favor of passing inputs directly
@@ -1455,6 +1463,12 @@ RPCHelpMan sendall()
                 }
             }
 
+            if (coin_control.m_version == TRUC_VERSION) {
+                coin_control.m_max_tx_weight = TRUC_MAX_WEIGHT;
+            } else {
+                coin_control.m_max_tx_weight = MAX_STANDARD_TX_WEIGHT;
+            }
+
             const bool rbf{options.exists("replaceable") ? options["replaceable"].get_bool() : pwallet->m_signal_rbf};
 
             FeeCalculation fee_calc_out;
@@ -1497,6 +1511,10 @@ RPCHelpMan sendall()
                     if (send_max && fee_rate.GetFee(output.input_bytes) > output.txout.nValue) {
                         continue;
                     }
+                    // we are spending an unconfirmed TRUC transaction, so lower max weight
+                    if (output.depth == 0 && coin_control.m_version == TRUC_VERSION) {
+                        coin_control.m_max_tx_weight = TRUC_CHILD_MAX_WEIGHT;
+                    }
                     CTxIn input(output.outpoint.hash, output.outpoint.n, CScript(), rbf ? MAX_BIP125_RBF_SEQUENCE : CTxIn::SEQUENCE_FINAL);
                     rawTx.vin.push_back(input);
                     total_input_value += output.txout.nValue;
@@ -1529,7 +1547,7 @@ RPCHelpMan sendall()
             }
 
             // If this transaction is too large, e.g. because the wallet has many UTXOs, it will be rejected by the node's mempool.
-            if (tx_size.weight > MAX_STANDARD_TX_WEIGHT) {
+            if (tx_size.weight > coin_control.m_max_tx_weight) {
                 throw JSONRPCError(RPC_WALLET_ERROR, "Transaction too large.");
             }
 
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index b65317b8..d76e6118 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -925,11 +925,17 @@ util::Result<SelectionResult> AutomaticCoinSelection(const CWallet& wallet, Coin
         // If no solution is found, return the first detailed error (if any).
         // future: add "error level" so the worst one can be picked instead.
         std::vector<util::Result<SelectionResult>> res_detailed_errors;
+        CoinSelectionParams updated_selection_params = coin_selection_params;
         for (const auto& select_filter : ordered_filters) {
             auto it = filtered_groups.find(select_filter.filter);
             if (it == filtered_groups.end()) continue;
+            if (updated_selection_params.m_version == TRUC_VERSION && (select_filter.filter.conf_mine == 0 || select_filter.filter.conf_theirs == 0)) {
+                if (updated_selection_params.m_max_tx_weight > (TRUC_CHILD_MAX_WEIGHT)) {
+                    updated_selection_params.m_max_tx_weight = TRUC_CHILD_MAX_WEIGHT;
+                }
+            }
             if (auto res{AttemptSelection(wallet.chain(), value_to_select, it->second,
-                                          coin_selection_params, select_filter.allow_mixed_output_types)}) {
+                                          updated_selection_params, select_filter.allow_mixed_output_types)}) {
                 return res; // result found
             } else {
                 // If any specific error message appears here, then something particularly wrong might have happened.
@@ -1046,6 +1052,7 @@ static util::Result<CreatedTransactionResult> CreateTransactionInternal(
     coin_selection_params.m_avoid_partial_spends = coin_control.m_avoid_partial_spends;
     coin_selection_params.m_include_unsafe_inputs = coin_control.m_include_unsafe_inputs;
     coin_selection_params.m_max_tx_weight = coin_control.m_max_tx_weight.value_or(MAX_STANDARD_TX_WEIGHT);
+    coin_selection_params.m_version = coin_control.m_version;
     int minimum_tx_weight = MIN_STANDARD_TX_NONWITNESS_SIZE * WITNESS_SCALE_FACTOR;
     if (coin_selection_params.m_max_tx_weight.value() < minimum_tx_weight || coin_selection_params.m_max_tx_weight.value() > MAX_STANDARD_TX_WEIGHT) {
         return util::Error{strprintf(_("Maximum transaction weight must be between %d and %d"), minimum_tx_weight, MAX_STANDARD_TX_WEIGHT)};