Fix for bug #32260: User variables in query cause server crash

  
Problem: there's no guarantee that the user variable item's result_field
is assigned when we're adjusting its table read map.
  
Fix: check the result_field before using it.


mysql-test/r/user_var.result:
  Fix for bug #32260: User variables in query cause server crash
    - test result.
mysql-test/t/user_var.test:
  Fix for bug #32260: User variables in query cause server crash
    - test case.
sql/item_func.cc:
  Fix for bug #32260: User variables in query cause server crash
    - using the result_field ensure it is set.

1 files changed, 11 insertions, 0 deletions

diff --git a/mysql-test/r/user_var.result b/mysql-test/r/user_var.result
index 6fd7b39f226..431134b03c7 100644
--- a/mysql-test/r/user_var.result
+++ b/mysql-test/r/user_var.result
@@ -353,3 +353,14 @@ select @a:=f4, count(f4) from t1 group by 1 desc;
 2.6	1
 1.6	4
 drop table t1;
+create table t1(a int);
+insert into t1 values(5),(4),(4),(3),(2),(2),(2),(1);
+set @rownum := 0;
+set @rank := 0;
+set @prev_score := NULL;
+select @rownum := @rownum + 1 as row,
+@rank := IF(@prev_score!=a, @rownum, @rank) as rank,
+@prev_score := a as score
+from t1 order by score desc;
+drop table t1;
+End of 5.1 tests