[Maria-developers] convert_tz unexpectedly returning fractional seconds

Using the ubuntu 14.04 mariadb (5.5.46), convert_tz unexpectedly returns a time with fractional seconds if its first argument is an expression using a column. This doesn't happen with mysqldb 5.5.46. Example: select convert_tz(concat('2006-05-25 17:45:00',''),'+00:00','+00:00') no_columns_used, convert_tz(concat('2006-05-25 17:45:00',blank),'+00:00','+00:00') column_used from (select '' blank) foo \G *************************** 1. row *************************** no_columns_used: 2006-05-25 17:45:00 column_used: 2006-05-25 17:45:00.000000