Cast MYSQL_TYPE_DECIMAL AND MYSQL_TYPE_NEWDECIMAL to integer if number of decimals is 0

Otherwise aggregate functions like SUM will produce decimals even when summing integers

Author: wok

ext/mysql2/result.c

@@ -237,7 +237,9 @@ static VALUE rb_mysql_result_fetch_row(VALUE self, ID db_timezone, ID app_timezo
           break;
         case MYSQL_TYPE_DECIMAL:    // DECIMAL or NUMERIC field
         case MYSQL_TYPE_NEWDECIMAL: // Precision math DECIMAL or NUMERIC field (MySQL 5.0.3 and up)
-          if (strtod(row[i], NULL) == 0.000000){
+          if (fields[i].decimals == 0) {
+            val = rb_cstr2inum(row[i], 10);
+          } else if (strtod(row[i], NULL) == 0.000000){
             val = rb_funcall(cBigDecimal, intern_new, 1, opt_decimal_zero);
           }else{
             val = rb_funcall(cBigDecimal, intern_new, 1, rb_str_new(row[i], fieldLengths[i]));