Allow saving list_errors output to file

libraries/api/general_api.json

@@ -178,6 +178,12 @@
                   "description" : "the maximum number of errors to return",
                   "type" : "uint32_t",
                   "default_value" : "20"
+               },
+               {
+                  "name" : "filename",
+                  "type" : "string",
+                  "description" : "the filename to save json error list to",
+                  "default_value" : ""
                }
         ],
         "is_const"   : true,

libraries/blockchain/chain_database.cpp

@@ -1735,6 +1735,7 @@ namespace bts { namespace blockchain {
       if( filename == "" )
           return out.str();
 
+      FC_ASSERT( !fc::exists( fc::path( filename ) ) );
       std::ofstream fileout( filename.generic_string().c_str() );
       fileout << out.str();
 

libraries/client/client.cpp

@@ -2523,7 +2523,7 @@ config load_config( const fc::path& datadir )
       return _chain_db->get_transactions_for_block(id);
    }
 
-   map<fc::time_point, fc::exception> client_impl::list_errors( const fc::time_point& start_time, int32_t first_error_number, uint32_t limit )const
+   map<fc::time_point, fc::exception> client_impl::list_errors( const fc::time_point& start_time, int32_t first_error_number, uint32_t limit, const string& filename )const
    {
       map<fc::time_point, fc::exception> result;
       auto itr = _exception_db.lower_bound( start_time );
@@ -2536,8 +2536,17 @@ config load_config( const fc::path& datadir )
          if (--limit == 0)
              break;
       }
+
+      if( filename != "" )
+      {
+          auto file_path = fc::path( filename );
+          FC_ASSERT( !fc::exists( file_path ) );
+          fc::json::save_to_file( result, file_path, true );
+      }
+
       return result;
    }
+
    map<fc::time_point, std::string> client_impl::list_errors_brief( const fc::time_point& start_time, int32_t first_error_number, uint32_t limit )const
    {
       map<fc::time_point, std::string> result;