no test case needed since simply creating a partitioned table 
reproduces it.


sql/sql_partition.cc:
  the O_RDWR mode and MY_WME were used in this code before the switch
  was made to create_temp_file.  The parameters are still there
  so we just plug in the mode and WME so the underlying code will 
  create the temp file with the right mode.  This only affected 
  Windows.