mysql-test/r/union.result:
  Added test for lp:732124
mysql-test/t/union.test:
  Added test for lp:732124
sql/sp_rcontext.cc:
  Updated function definition for ::send_data()
sql/sp_rcontext.h:
  Updated function definition for ::send_data()
sql/sql_analyse.cc:
  Test if send_data() returned an error
sql/sql_class.cc:
  Updated function definition for ::send_data()
sql/sql_class.h:
  Changed select_result::send_data(List<Item> &items) to return -1 in case of duplicate row that should not be counted as part of LIMIT
sql/sql_cursor.cc:
  Check if send_data returned error
sql/sql_delete.cc:
  Updated function definition for ::send_data()
sql/sql_insert.cc:
  Updated function definition for ::send_data()
sql/sql_select.cc:
  Don't count rows which send_data() tells you to ignore
sql/sql_union.cc:
  Inform caller that the row should be ignored. This is the real bug fix for lp:732124
sql/sql_update.cc:
  Updated function definition for ::send_data()