Merge pull request #1195 from cogutvalera/valera_issue_1109

CLI wallet: avoid directly overwriting wallet file on exit #1109

libraries/wallet/wallet.cpp

@@ -799,6 +799,7 @@ class wallet_api_impl
       wlog( "saving wallet to file ${fn}", ("fn", wallet_filename) );
 
       string data = fc::json::to_pretty_string( _wallet );
+
       try
       {
          enable_umask_protection();
@@ -808,14 +809,40 @@ class wallet_api_impl
          //
          // http://en.wikipedia.org/wiki/Most_vexing_parse
          //
-         fc::ofstream outfile{ fc::path( wallet_filename ) };
+         std::string tmp_wallet_filename = wallet_filename + ".tmp";
+         fc::ofstream outfile{ fc::path( tmp_wallet_filename ) };
          outfile.write( data.c_str(), data.length() );
          outfile.flush();
          outfile.close();
+
+         wlog( "saved successfully wallet to tmp file ${fn}", ("fn", tmp_wallet_filename) );
+
+         std::string wallet_file_content;
+         fc::read_file_contents(tmp_wallet_filename, wallet_file_content);
+
+         if (wallet_file_content == data) {
+            wlog( "validated successfully tmp wallet file ${fn}", ("fn", tmp_wallet_filename) );
+
+            fc::rename( tmp_wallet_filename, wallet_filename );
+
+            wlog( "renamed successfully tmp wallet file ${fn}", ("fn", tmp_wallet_filename) );
+         } 
+         else 
+         {
+            FC_THROW("tmp wallet file cannot be validated ${fn}", ("fn", tmp_wallet_filename) );
+         }
+
+         wlog( "successfully saved wallet to file ${fn}", ("fn", wallet_filename) );
+
          disable_umask_protection();
       }
       catch(...)
       {
+         string ws_password = _wallet.ws_password;
+         _wallet.ws_password = "";
+         wlog("wallet file content is next: ${data}", ("data", fc::json::to_pretty_string( _wallet ) ) );
+         _wallet.ws_password = ws_password;
+
          disable_umask_protection();
          throw;
       }