[txorphanage] add GetTx so that orphan vin can be read

src/test/fuzz/txorphan.cpp

@@ -157,5 +157,8 @@ FUZZ_TARGET(txorphan, .init = initialize_orphanage)
             ptx_potential_parent = tx;
         }
 
+        const bool have_tx{orphanage.HaveTx(tx->GetWitnessHash())};
+        const bool get_tx_nonnull{orphanage.GetTx(tx->GetWitnessHash()) != nullptr};
+        Assert(have_tx == get_tx_nonnull);
     }
 }

src/test/orphanage_tests.cpp

@@ -250,7 +250,9 @@ BOOST_AUTO_TEST_CASE(same_txid_diff_witness)
     // EraseTx fails as transaction by this wtxid doesn't exist.
     BOOST_CHECK_EQUAL(orphanage.EraseTx(mutated_wtxid), 0);
     BOOST_CHECK(orphanage.HaveTx(normal_wtxid));
+    BOOST_CHECK(orphanage.GetTx(normal_wtxid) == child_normal);
     BOOST_CHECK(!orphanage.HaveTx(mutated_wtxid));
+    BOOST_CHECK(orphanage.GetTx(mutated_wtxid) == nullptr);
 
     // Must succeed. Both transactions should be present in orphanage.
     BOOST_CHECK(orphanage.AddTx(child_mutated, peer));

src/txorphanage.cpp

@@ -179,6 +179,12 @@ bool TxOrphanage::HaveTx(const Wtxid& wtxid) const
     return m_orphans.count(wtxid);
 }
 
+CTransactionRef TxOrphanage::GetTx(const Wtxid& wtxid) const
+{
+    auto it = m_orphans.find(wtxid);
+    return it != m_orphans.end() ? it->second.tx : nullptr;
+}
+
 bool TxOrphanage::HaveTxFromPeer(const Wtxid& wtxid, NodeId peer) const
 {
     auto it = m_orphans.find(wtxid);

src/txorphanage.h

@@ -33,6 +33,8 @@ public:
     /** Add an additional announcer to an orphan if it exists. Otherwise, do nothing. */
     bool AddAnnouncer(const Wtxid& wtxid, NodeId peer);
 
+    CTransactionRef GetTx(const Wtxid& wtxid) const;
+
     /** Check if we already have an orphan transaction (by wtxid only) */
     bool HaveTx(const Wtxid& wtxid) const;