incorrect results when the input was a constant across a multi-row SELECT
statement. (Bug #8248)


sql/item_strfunc.h:
  Add tmp_value member
sql/item_strfunc.cc:
  Always allocate a new string for QUOTE(), in case the field is being reused
  for multiple rows.
mysql-test/t/func_str.test:
  Add regression test
mysql-test/r/func_str.result:
  Add test results