Fixes #759 Add sanity check on restore height

src/simplewallet/simplewallet.cpp

@@ -1588,8 +1588,18 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
       }
     }
     if (m_restoring)
+    {
+      uint64_t estimate_height = m_wallet->estimate_blockchain_height();
+      if (m_restore_height >= estimate_height)
+      {
+        success_msg_writer() << tr("Restore height ") << m_restore_height << (" is not yet reached. The current estimated height is ") << estimate_height;
+        std::string confirm = input_line(tr("Still apply restore height?  (Y/Yes/N/No): "));
+        if (std::cin.eof() || command_line::is_no(confirm))
+          m_restore_height = 0;
+      }
       m_wallet->set_refresh_from_block_height(m_restore_height);
     }
+  }
   else
   {
     assert(!m_wallet_file.empty());

src/wallet/wallet2.cpp

@@ -2413,6 +2413,34 @@ crypto::secret_key wallet2::generate(const std::string& wallet_, const std::stri
 
   // try asking the daemon first
   if(m_refresh_from_block_height == 0 && !recover){
+    uint64_t height = estimate_blockchain_height();
+    m_refresh_from_block_height = height >= blocks_per_month ? height - blocks_per_month : 0;
+  }
+
+  bool r = store_keys(m_keys_file, password, false);
+  THROW_WALLET_EXCEPTION_IF(!r, error::file_save_error, m_keys_file);
+
+  r = file_io_utils::save_string_to_file(m_wallet_file + ".address.txt", m_account.get_public_address_str(m_testnet));
+  if(!r) MERROR("String with address text not saved");
+
+  cryptonote::block b;
+  generate_genesis(b);
+  m_blockchain.push_back(get_block_hash(b));
+  add_subaddress_account(tr("Primary account"));
+
+  store();
+  return retval;
+}
+
+ uint64_t wallet2::estimate_blockchain_height()
+ {
+   // -1 month for fluctuations in block time and machine date/time setup.
+   // avg seconds per block
+   const int seconds_per_block = DIFFICULTY_TARGET_V2;
+   // ~num blocks per month
+   const uint64_t blocks_per_month = 60*60*24*30/seconds_per_block;
+
+   // try asking the daemon first
    std::string err;
    uint64_t height = 0;
 
@@ -2433,24 +2461,9 @@ crypto::secret_key wallet2::generate(const std::string& wallet_, const std::stri
    uint64_t local_height = get_daemon_blockchain_height(err);
    if (err.empty() && local_height > height)
      height = local_height;
-    m_refresh_from_block_height = height >= blocks_per_month ? height - blocks_per_month : 0;
+   return height;
  }
 
-  bool r = store_keys(m_keys_file, password, false);
-  THROW_WALLET_EXCEPTION_IF(!r, error::file_save_error, m_keys_file);
-
-  r = file_io_utils::save_string_to_file(m_wallet_file + ".address.txt", m_account.get_public_address_str(m_testnet));
-  if(!r) MERROR("String with address text not saved");
-
-  cryptonote::block b;
-  generate_genesis(b);
-  m_blockchain.push_back(get_block_hash(b));
-  add_subaddress_account(tr("Primary account"));
-
-  store();
-  return retval;
-}
-
 /*!
 * \brief Creates a watch only wallet from a public address and a view secret key.
 * \param  wallet_        Name of wallet file

src/wallet/wallet2.h

@@ -709,6 +709,7 @@ namespace tools
     * \brief Calculates the approximate blockchain height from current date/time.
     */
     uint64_t get_approximate_blockchain_height() const;
+    uint64_t estimate_blockchain_height();
     std::vector<size_t> select_available_outputs_from_histogram(uint64_t count, bool atleast, bool unlocked, bool allow_rct, bool trusted_daemon);
     std::vector<size_t> select_available_outputs(const std::function<bool(const transfer_details &td)> &f);
     std::vector<size_t> select_available_unmixable_outputs(bool trusted_daemon);