refactor: add BuildNewListFromBlock overload accepting explicit prevList

UdjinM6 · claude · UdjinM6 · commit 496ed897c5a7 · 2025-11-13T03:24:45.000+03:00
Add overload that takes an explicit starting CDeterministicMNList instead of
loading from GetListForBlock. This allows rebuilding masternode lists from
trusted snapshots without depending on potentially corrupted diffs in the
database.

Key changes:
- Add new overload taking prevList parameter (specialtxman.h)
- Refactor original method to delegate to new overload (specialtxman.cpp)
- Add assert to verify prevList is either empty or matches previous block
- Skip collateral validation when using dummy coins view (historical blocks)

Co-authored-by: Claude (Anthropic AI) &lt;noreply@anthropic.com&gt;
diff --git a/src/evo/specialtxman.cpp b/src/evo/specialtxman.cpp
@@ -176,10 +176,24 @@ bool CSpecialTxProcessor::BuildNewListFromBlock(const CBlock& block, gsl::not_nu
                                                 BlockValidationState& state, CDeterministicMNList& mnListRet)
 {
     AssertLockHeld(cs_main);
+    CDeterministicMNList oldList = m_dmnman.GetListForBlock(pindexPrev);
+    return BuildNewListFromBlock(block, pindexPrev, oldList, view, debugLogs, state, mnListRet);
+}
+
+bool CSpecialTxProcessor::BuildNewListFromBlock(const CBlock& block, gsl::not_null<const CBlockIndex*> pindexPrev,
+                                                const CDeterministicMNList& prevList, const CCoinsViewCache& view,
+                                                bool debugLogs, BlockValidationState& state,
+                                                CDeterministicMNList& mnListRet)
+{
+    AssertLockHeld(cs_main);
+
+    // Verify that prevList either represents an empty/initial state (default-constructed),
+    // or it matches the previous block's hash.
+    assert(prevList == CDeterministicMNList() || prevList.GetBlockHash() == pindexPrev->GetBlockHash());
 
     int nHeight = pindexPrev->nHeight + 1;
 
-    CDeterministicMNList oldList = m_dmnman.GetListForBlock(pindexPrev);
+    CDeterministicMNList oldList = prevList;
     CDeterministicMNList newList = oldList;
     newList.SetBlockHash(uint256()); // we can't know the final block hash, so better not return a (invalid) block hash
     newList.SetHeight(nHeight);
@@ -235,13 +249,18 @@ bool CSpecialTxProcessor::BuildNewListFromBlock(const CBlock& block, gsl::not_nu
                 dmn->collateralOutpoint = proTx.collateralOutpoint;
             }
 
-            Coin coin;
-            CAmount expectedCollateral = GetMnType(proTx.nType).collat_amount;
-            if (!proTx.collateralOutpoint.hash.IsNull() && (!view.GetCoin(dmn->collateralOutpoint, coin) ||
-                                                            coin.IsSpent() || coin.out.nValue != expectedCollateral)) {
-                // should actually never get to this point as CheckProRegTx should have handled this case.
-                // We do this additional check nevertheless to be 100% sure
-                return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-protx-collateral");
+            // Complain about spent collaterals only when we process the tip.
+            // This is safe because blocks below the tip were verified
+            // when they were connected initially.
+            if (!view.GetBestBlock().IsNull()) {
+                Coin coin;
+                CAmount expectedCollateral = GetMnType(proTx.nType).collat_amount;
+                if (!proTx.collateralOutpoint.hash.IsNull() && (!view.GetCoin(dmn->collateralOutpoint, coin) ||
+                                                                coin.IsSpent() || coin.out.nValue != expectedCollateral)) {
+                    // should actually never get to this point as CheckProRegTx should have handled this case.
+                    // We do this additional check nevertheless to be 100% sure
+                    return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-protx-collateral");
+                }
             }
 
             auto replacedDmn = newList.GetMNByCollateral(dmn->collateralOutpoint);
diff --git a/src/evo/specialtxman.h b/src/evo/specialtxman.h
@@ -79,6 +79,13 @@ class CSpecialTxProcessor
                                const CCoinsViewCache& view, bool debugLogs, BlockValidationState& state,
                                CDeterministicMNList& mnListRet) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
+    // Variant that takes an explicit starting list instead of loading from GetListForBlock
+    // Used for rebuilding diffs from trusted snapshots
+    bool BuildNewListFromBlock(const CBlock& block, gsl::not_null<const CBlockIndex*> pindexPrev,
+                               const CDeterministicMNList& prevList, const CCoinsViewCache& view, bool debugLogs,
+                               BlockValidationState& state, CDeterministicMNList& mnListRet)
+        EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+
 private:
     bool CheckCreditPoolDiffForBlock(const CBlock& block, const CBlockIndex* pindex, const CCbTx& cbTx,
                                      BlockValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
