merge of MDEV-5356 5.1->5.3 (with more fixes and test suite).

THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
  1) func1 saves current arena and activates copy1 of statement arena
  2) func2 saves copy1 of statement arena setup by func1 and activates copy2
  3) some changes made for copy 2
  4) func2 stores changed copy2 back to statenet arena and activates copy1
  5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.

1 files changed, 22 insertions, 0 deletions

diff --git a/mysql-test/r/derived.result b/mysql-test/r/derived.result
index 3ad9d99651a..dcf54d55886 100644
--- a/mysql-test/r/derived.result
+++ b/mysql-test/r/derived.result
@@ -479,5 +479,27 @@ SELECT * FROM
 WHERE tmp.a;
 a	b
 100	200
+#
+# MDEV-5356: Server crashes in Item_equal::contains on 2nd
+# execution of a PS
+#
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1,2),(3,4);
+CREATE TABLE t2 (c INT);
+INSERT INTO t2 VALUES (5),(6);
+CREATE TABLE t3 (d INT);
+INSERT INTO t3 VALUES (7),(8);
+CREATE PROCEDURE pr()
+UPDATE t3,
+(SELECT c FROM
+(SELECT 1 FROM t1 WHERE a=72 AND NOT b) sq, 
+t2
+) sq2
+SET d=sq2.c;
+CALL pr();
+CALL pr();
+CALL pr();
+drop procedure pr;
+drop table t1,t2,t3;
 # End of 5.3 tests
 set optimizer_switch=@save_derived_optimizer_switch;