tests: Add fuzzing harness for functions/classes in merkleblock.h

src/test/fuzz/merkleblock.cpp

@@ -0,0 +1,27 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <merkleblock.h>
+#include <optional.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+#include <uint256.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    Optional<CPartialMerkleTree> partial_merkle_tree = ConsumeDeserializable<CPartialMerkleTree>(fuzzed_data_provider);
+    if (!partial_merkle_tree) {
+        return;
+    }
+    (void)partial_merkle_tree->GetNumTransactions();
+    std::vector<uint256> matches;
+    std::vector<unsigned int> indices;
+    (void)partial_merkle_tree->ExtractMatches(matches, indices);
+}