wallet: throw error at conflicting tx versions in pre-selected inputs

Author: ishaanam

src/wallet/spend.cpp

@@ -283,6 +283,14 @@ util::Result<PreSelectedInputs> FetchSelectedInputs(const CWallet& wallet, const
             if (input_bytes == -1) {
                 input_bytes = CalculateMaximumSignedInputSize(txout, &wallet, &coin_control);
             }
+            const CWalletTx& parent_tx = txo->GetWalletTx();
+            if (wallet.GetTxDepthInMainChain(parent_tx) == 0) {
+                if (parent_tx.tx->version == TRUC_VERSION && coin_control.m_version != TRUC_VERSION) {
+                    return util::Error{strprintf(_("Can't spend unconfirmed version 3 pre-selected input with a version %d tx"), coin_control.m_version)};
+                } else if (coin_control.m_version == TRUC_VERSION && parent_tx.tx->version != TRUC_VERSION) {
+                    return util::Error{strprintf(_("Can't spend unconfirmed version %d pre-selected input with a version 3 tx"), parent_tx.tx->version)};
+                }
+            }
         } else {
             // The input is external. We did not find the tx in mapWallet.
             const auto out{coin_control.GetExternalOutput(outpoint)};