Bug#20836 Selecting into variables results in wrong results being returned

This error is displayed anytime the SELECT statement needs a temp table to
return correct results because the object (select_dumpvar) that represents
variables named in the INTO clause stored the results before the temp
table was considered.  The problem was fixed by creating the necessary
Item_func_set_user_var objects once the correct data is ready.


mysql-test/r/distinct.result:
  Bug#20836 Selecting into variables results in wrong results being returned
  - Added results
mysql-test/t/distinct.test:
  Bug#20836 Selecting into variables results in wrong results being returned
  - Added various Selects that use the INTO statement and a temp table.
  - Added Select Into Outfile variant tests also.
sql/sql_class.cc:
  Bug#20836 Selecting into variables results in wrong results being returned
  - The select_dumpvar variable created a Item_func_set_user_var too early
  and once set, it was not possible to change.  The Item_func_set_user_var
  is now created once the final results are available.
sql/sql_class.h:
  Bug#20836 Selecting into variables results in wrong results being returned
  - Removed unnecessary object members.

1 files changed, 1 insertions, 2 deletions

diff --git a/sql/sql_class.h b/sql/sql_class.h
index 7cf0b474ed7..b61403e4b0a 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -1573,8 +1573,7 @@ class select_dumpvar :public select_result_interceptor {
   ha_rows row_count;
 public:
   List<LEX_STRING> var_list;
-  List<Item_func_set_user_var> vars;
-  select_dumpvar(void)  { var_list.empty(); vars.empty(); row_count=0;}
+  select_dumpvar()  { var_list.empty(); row_count= 0;}
   ~select_dumpvar() {}
   int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
   bool send_data(List<Item> &items);