text: // Copyright (c) 2020 The C1pzo Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <optional.h>
  #include <streams.h>
  #include <test/fuzz/FuzzedDataProvider.h>
  #include <test/fuzz/fuzz.h>
  #include <test/fuzz/util.h>
  
  #include <array>
  #include <cstdint>
  #include <iostream>
  #include <optional>
  #include <string>
  #include <vector>
  
  FUZZ_TARGET(buffered_file)
  {
      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
      FuzzedFileProvider fuzzed_file_provider = ConsumeFile(fuzzed_data_provider);
      std::optional<CBufferedFile> opt_buffered_file;
      FILE* fuzzed_file = fuzzed_file_provider.open();
      try {
          opt_buffered_file.emplace(fuzzed_file, fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeIntegral<int>());
      } catch (const std::ios_base::failure&) {
          if (fuzzed_file != nullptr) {
              fclose(fuzzed_file);
          }
      }
      if (opt_buffered_file && fuzzed_file != nullptr) {
          bool setpos_fail = false;
          while (fuzzed_data_provider.ConsumeBool()) {
              CallOneOf(
                  fuzzed_data_provider,
                  [&] {
                      std::array<uint8_t, 4096> arr{};
                      try {
                          opt_buffered_file->read((char*)arr.data(), fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096));
                      } catch (const std::ios_base::failure&) {
                      }
                  },
                  [&] {
                      opt_buffered_file->SetLimit(fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096));
                  },
                  [&] {
                      if (!opt_buffered_file->SetPos(fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096))) {
                          setpos_fail = true;
                      }
                  },
                  [&] {
                      if (setpos_fail) {
                          // Calling FindByte(...) after a failed SetPos(...) call may result in an infinite loop.
                          return;
                      }
                      try {
                          opt_buffered_file->FindByte(fuzzed_data_provider.ConsumeIntegral<char>());
                      } catch (const std::ios_base::failure&) {
                      }
                  },
                  [&] {
                      ReadFromStream(fuzzed_data_provider, *opt_buffered_file);
                  });
          }
          opt_buffered_file->GetPos();
          opt_buffered_file->GetType();
          opt_buffered_file->GetVersion();
      }
  }
  