test/fuzz: Invoke LoadMempool via CChainState

Not only does this increase coverage, it is also more correct in that
when ::LoadMempool is called with a mempool and chainstate, it calls
AcceptToMemoryPool with just the chainstate.

AcceptToMemoryPool will then act on the chainstate's mempool via
CChainState::GetMempool, which may be different from the mempool
originally passed to ::LoadMempool. (In this fuzz test's case, it
definitely is different)

Also, move DummyChainstate to its own file since it's now used by the
validation_load_mempool fuzz test to replace CChainState's m_mempool.

1 files changed, 1 insertions, 9 deletions

diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index 2d88ee295b..63fbf0516a 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -8,6 +8,7 @@
 #include <node/miner.h>
 #include <test/fuzz/FuzzedDataProvider.h>
 #include <test/fuzz/fuzz.h>
+#include <test/fuzz/mempool_utils.h>
 #include <test/fuzz/util.h>
 #include <test/util/mining.h>
 #include <test/util/script.h>
@@ -34,15 +35,6 @@ struct MockedTxPool : public CTxMemPool {
     }
 };
 
-class DummyChainState final : public CChainState
-{
-public:
-    void SetMempool(CTxMemPool* mempool)
-    {
-        m_mempool = mempool;
-    }
-};
-
 void initialize_tx_pool()
 {
     static const auto testing_setup = MakeNoLogFileContext<const TestingSetup>();