Merge bitcoin/bitcoin#25677: refactor: make active_chain_tip a reference

9376a6dae41022874df3b9302667796a9fb7b81d refactor: make active_chain_tip a reference (Aurèle Oulès)

Pull request description:

  This PR fixes a TODO introduced in #21055.

  Makes `active_chain_tip` argument in `CheckFinalTxAtTip` function a reference instead of a pointer.

ACKs for top commit:
  dongcarl:
    ACK 9376a6dae41022874df3b9302667796a9fb7b81d

Tree-SHA512: c36d1769e0b9598b7f79334704b26b73e958d54caa3bd7e4eff954f3964fcf3f5e3a44a5a760497afad51b76e1614c86314fe035e4083c855e3574a620de7f4d

1 files changed, 5 insertions, 6 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index d30333f710..d276cea2f7 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -157,10 +157,9 @@ bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
                        std::vector<CScriptCheck>* pvChecks = nullptr)
                        EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-bool CheckFinalTxAtTip(const CBlockIndex* active_chain_tip, const CTransaction& tx)
+bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx)
 {
     AssertLockHeld(cs_main);
-    assert(active_chain_tip); // TODO: Make active_chain_tip a reference
 
     // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate
     // nLockTime because when IsFinalTx() is called within
@@ -168,14 +167,14 @@ bool CheckFinalTxAtTip(const CBlockIndex* active_chain_tip, const CTransaction&
     // evaluated is what is used. Thus if we want to know if a
     // transaction can be part of the *next* block, we need to call
     // IsFinalTx() with one more than active_chain_tip.Height().
-    const int nBlockHeight = active_chain_tip->nHeight + 1;
+    const int nBlockHeight = active_chain_tip.nHeight + 1;
 
     // BIP113 requires that time-locked transactions have nLockTime set to
     // less than the median time of the previous block they're contained in.
     // When the next block is created its previous block will be the current
     // chain tip, so we use that to calculate the median time passed to
     // IsFinalTx().
-    const int64_t nBlockTime{active_chain_tip->GetMedianTimePast()};
+    const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()};
 
     return IsFinalTx(tx, nBlockHeight, nBlockTime);
 }
@@ -337,7 +336,7 @@ void CChainState::MaybeUpdateMempoolForReorg(
         const CTransaction& tx = it->GetTx();
 
         // The transaction must be final.
-        if (!CheckFinalTxAtTip(m_chain.Tip(), tx)) return true;
+        if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true;
         LockPoints lp = it->GetLockPoints();
         const bool validLP{TestLockPointValidity(m_chain, lp)};
         CCoinsViewMemPool view_mempool(&CoinsTip(), *m_mempool);
@@ -714,7 +713,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
-    if (!CheckFinalTxAtTip(m_active_chainstate.m_chain.Tip(), tx)) {
+    if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) {
         return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final");
     }