Prove that the queries mentioned in
  Bugs#5980: NULL requires a characterset in a union
  works fine after recent changes related to itroducing
  more coercibility level: IRNORABLE and SYSCONST.


mysql-test/r/ctype_utf8.result:
  Prove that the queries mentioned in
  Bugs#5980: NULL requires a characterset in a union
  works fine after recent changes related to itroducing
  more coercibility level: IRNORABLE and SYSCONST.
mysql-test/r/func_system.result:
  Prove that the queries mentioned in
  Bugs#5980: NULL requires a characterset in a union
  works fine after recent changes related to itroducing
  more coercibility level: IRNORABLE and SYSCONST.
mysql-test/t/ctype_utf8.test:
  Prove that the queries mentioned in
  Bugs#5980: NULL requires a characterset in a union
  works fine after recent changes related to itroducing
  more coercibility level: IRNORABLE and SYSCONST.
mysql-test/t/func_system.test:
  Prove that the queries mentioned in
  Bugs#5980: NULL requires a characterset in a union
  works fine after recent changes related to itroducing
  more coercibility level: IRNORABLE and SYSCONST.