refactor: Change FindTxForGetData to take GenTxid instead of CInv

Addresses
bitcoin/bitcoin#32631 (comment)
from #32631

Author: marcofleon

src/net_processing.cpp

@@ -947,7 +947,7 @@ class PeerManagerImpl final : public PeerManager
     std::atomic<std::chrono::seconds> m_last_tip_update{0s};
 
     /** Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed). */
-    CTransactionRef FindTxForGetData(const Peer::TxRelay& tx_relay, const CInv& inv)
+    CTransactionRef FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
         EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, NetEventsInterface::g_msgproc_mutex);
 
     void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
@@ -2391,15 +2391,14 @@ void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv&
     }
 }
 
-CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay, const CInv& inv)
+CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
 {
-    auto gtxid{ToGenTxid(inv)};
-    // If a tx was in the mempool prior to the last INV for this peer, permit the request.
     auto txinfo{std::visit(
         [&](const auto& id) EXCLUSIVE_LOCKS_REQUIRED(NetEventsInterface::g_msgproc_mutex) {
             return m_mempool.info_for_relay(id, tx_relay.m_last_inv_sequence);
         },
         gtxid)};
+
     if (txinfo.tx) {
         return std::move(txinfo.tx);
     }
@@ -2442,7 +2441,7 @@ void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic
             continue;
         }
 
-        if (auto tx{FindTxForGetData(*tx_relay, inv)}) {
+        if (auto tx{FindTxForGetData(*tx_relay, ToGenTxid(inv))}) {
             // WTX and WITNESS_TX imply we serialize with witness
             const auto maybe_with_witness = (inv.IsMsgTx() ? TX_NO_WITNESS : TX_WITH_WITNESS);
             MakeAndPushMessage(pfrom, NetMsgType::TX, maybe_with_witness(*tx));