fuzz: don't bypass_limits for most mempool harnesses

Using bypass_limits=true is essentially fuzzing part of a
reorg only, and results in TRUC invariants unable to be
checked. Remove most instances of bypassing limits, leaving
one harness able to do so.

Author: instagibbs

src/test/fuzz/package_eval.cpp

@@ -325,7 +325,7 @@ FUZZ_TARGET(ephemeral_package_eval, .init = initialize_tx_pool)
                                     return ProcessNewPackage(chainstate, tx_pool, txs, /*test_accept=*/single_submit, /*client_maxfeerate=*/{}));
 
         const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, txs.back(), GetTime(),
-                                   /*bypass_limits=*/fuzzed_data_provider.ConsumeBool(), /*test_accept=*/!single_submit));
+                                   /*bypass_limits=*/false, /*test_accept=*/!single_submit));
 
         if (!single_submit && result_package.m_state.GetResult() != PackageValidationResult::PCKG_POLICY) {
             // We don't know anything about the validity since transactions were randomly generated, so

src/test/fuzz/tx_pool.cpp

@@ -296,7 +296,6 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
         std::set<CTransactionRef> added;
         auto txr = std::make_shared<TransactionsDelta>(removed, added);
         node.validation_signals->RegisterSharedValidationInterface(txr);
-        const bool bypass_limits = fuzzed_data_provider.ConsumeBool();
 
         // Make sure ProcessNewPackage on one transaction works.
         // The result is not guaranteed to be the same as what is returned by ATMP.
@@ -311,7 +310,7 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
                    it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID);
         }
 
-        const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx, GetTime(), bypass_limits, /*test_accept=*/false));
+        const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx, GetTime(), /*bypass_limits=*/false, /*test_accept=*/false));
         const bool accepted = res.m_result_type == MempoolAcceptResult::ResultType::VALID;
         node.validation_signals->SyncWithValidationInterfaceQueue();
         node.validation_signals->UnregisterSharedValidationInterface(txr);
@@ -394,6 +393,9 @@ FUZZ_TARGET(tx_pool, .init = initialize_tx_pool)
 
     chainstate.SetMempool(&tx_pool);
 
+    // If we ever bypass limits, do not do TRUC invariants checks
+    bool ever_bypassed_limits{false};
+
     LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 300)
     {
         const auto mut_tx = ConsumeTransaction(fuzzed_data_provider, txids);
@@ -412,13 +414,17 @@ FUZZ_TARGET(tx_pool, .init = initialize_tx_pool)
             tx_pool.PrioritiseTransaction(txid, delta);
         }
 
+        const bool bypass_limits{fuzzed_data_provider.ConsumeBool()};
+        ever_bypassed_limits |= bypass_limits;
+
         const auto tx = MakeTransactionRef(mut_tx);
-        const bool bypass_limits = fuzzed_data_provider.ConsumeBool();
         const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx, GetTime(), bypass_limits, /*test_accept=*/false));
         const bool accepted = res.m_result_type == MempoolAcceptResult::ResultType::VALID;
         if (accepted) {
             txids.push_back(tx->GetHash());
-            CheckMempoolTRUCInvariants(tx_pool);
+            if (!ever_bypassed_limits) {
+                CheckMempoolTRUCInvariants(tx_pool);
+            }
         }
     }
     Finish(fuzzed_data_provider, tx_pool, chainstate);