message: txdb: don't reset during in-memory cache resize
  We can't support a reset of the dbwrapper object when in-memory configuration is used
  because it results in the permanent loss of coins. This only affects unittest
  configurations (since that's the only place we use in-memory CCoinsViewDB instances).
diff: @@ -47,12 +47,16 @@ CCoinsViewDB::CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory, b
  void CCoinsViewDB::ResizeCache(size_t new_cache_size)
  {
  + // We can't do this operation with an in-memory DB since we'll lose all the coins upon
  + // reset.
  + if (!m_is_memory) {
  // Have to do a reset first to get the original `m_db` state to release its
  // filesystem lock.
  m_db.reset();
  m_db = MakeUnique<CDBWrapper>(
  m_ldb_path, new_cache_size, m_is_memory, /*fWipe*/ false, /*obfuscate*/ true);
  }
  +}
  bool CCoinsViewDB::GetCoin(const COutPoint &outpoint, Coin &coin) const {
  return m_db->Read(CoinEntry(&outpoint), coin);
  