There actually was 3 different problems -
hash_user_connections wasn't cleaned
one strdupped database name wasn't freed
and stmt->mem_root wasn't cleaned as it was
replased with mysql->field_alloc for result
For the last one - i made the library using stmt's
fields to store result if it's the case.


include/mysql.h:
  statement pointer added to the advanced_command to be checked in
  embedded server
include/sql_common.h:
  stmt added to the cli_advanced_command interface
libmysql/libmysql.c:
  stmt pointer now sent to advanced_command
libmysqld/embedded_priv.h:
  it's enough to send database name to check_embedded_connection
libmysqld/lib_sql.cc:
  Now we store result directly in the MYSQL_STMT structure to
  avoid extra copying
libmysqld/libmysqld.c:
  it's enough to only send database pointer to check_embedded_connection
sql-common/client.c:
  stmt fake attribute added to cli_advanced_command
sql/sql_parse.cc:
  hash_user_connections isn't used if no access checks compiled