exit if specified wallet file doesn't exist

src/simplewallet/simplewallet.cpp

@@ -3456,6 +3456,17 @@ bool simple_wallet::open_wallet(const boost::program_options::variables_map& vm)
     fail_msg_writer() << tr("wallet file path not valid: ") << m_wallet_file;
     return false;
   }
+
+  bool keys_file_exists;
+  bool wallet_file_exists;
+
+  tools::wallet2::wallet_exists(m_wallet_file, keys_file_exists, wallet_file_exists);
+  if(!keys_file_exists)
+  {
+    fail_msg_writer() << tr("Key file not found. Failed to open wallet");
+    return false;
+  }
+  
   epee::wipeable_string password;
   try
   {