diff --git a/bdb/dist/s_all b/bdb/dist/s_all
index 132017def3c..97ce572a4ae 100644
--- a/bdb/dist/s_all
+++ b/bdb/dist/s_all
@@ -1,6 +1,21 @@
 #!/bin/sh -
 #	$Id: s_all,v 1.10 2001/08/04 14:01:44 bostic Exp $
 
+# Search an AWK program, use GNU awk if available
+for x in gawk awk ; do
+  if type $x; then
+    AWK=$x
+    break
+  fi
+done
+
+if test -z "$AWK"; then
+  echo 'No AWK program found'
+  exit 1
+fi
+export AWK
+# end of AWK search
+
 sh s_dir
 
 #sh s_perm		# permissions.
diff --git a/bdb/dist/s_include b/bdb/dist/s_include
index 878b4a38af1..5cb3a666dc0 100755
--- a/bdb/dist/s_include
+++ b/bdb/dist/s_include
@@ -79,7 +79,7 @@ for i in db btree clib common dbreg env fileops hash hmac \
 	[ $i = os ] && f="$f ../os_win32/*.c"
 	[ $i = rpc_server ] && f="../$i/c/*.c"
 	[ $i = crypto ] && f="../$i/*.c ../$i/*/*.c"
-	awk -f gen_inc.awk \
+	$AWK -f gen_inc.awk \
 	    -v db_version_unique_name=$DB_VERSION_UNIQUE_NAME \
 	    -v e_dfile=$e_dfile \
 	    -v e_pfile=$e_pfile \
@@ -97,7 +97,7 @@ done
 # files.
 for i in dbm hsearch; do
 	f="../$i/*.c"
-	awk -f gen_inc.awk \
+	$AWK -f gen_inc.awk \
 	    -v db_version_unique_name=$DB_VERSION_UNIQUE_NAME \
 	    -v e_dfile=$e_dfile \
 	    -v e_pfile=$e_pfile \
@@ -142,7 +142,7 @@ head space defonly _DB_EXT_185_DEF_IN_ > $e_dfile
 head space _DB_EXT_185_PROT_IN_ > $e_pfile
 
 f="../db185/*.c"
-awk -f gen_inc.awk \
+$AWK -f gen_inc.awk \
     -v db_version_unique_name=$DB_VERSION_UNIQUE_NAME \
     -v e_dfile=$e_dfile \
     -v e_pfile=$e_pfile \
diff --git a/bdb/dist/s_recover b/bdb/dist/s_recover
index fc2e160c083..f6d2ad33e5a 100755
--- a/bdb/dist/s_recover
+++ b/bdb/dist/s_recover
@@ -45,7 +45,7 @@ cmp $loglist $f > /dev/null 2>&1 ||
 for i in db dbreg btree fileops hash qam txn; do
 	for f in ../$i/*.src; do
 		subsystem=`basename $f .src`
-		awk -f gen_rec.awk \
+		$AWK -f gen_rec.awk \
 		    -v source_file=$source \
 		    -v header_file=$header \
 		    -v template_file=$template < $f
diff --git a/bdb/dist/s_rpc b/bdb/dist/s_rpc
index cdafa669d85..f9495ec121f 100644
--- a/bdb/dist/s_rpc
+++ b/bdb/dist/s_rpc
@@ -43,7 +43,7 @@ rm -f   $client_file \
 xidsize=\
 `awk '/^#define/ { if ($2 == "DB_XIDDATASIZE") { print $3 }}' $dbinc_file`
 
-awk -f gen_rpc.awk \
+$AWK -f gen_rpc.awk \
     -v major=$DB_VERSION_MAJOR \
     -v minor=$DB_VERSION_MINOR \
     -v xidsize=$xidsize \
diff --git a/configure.in b/configure.in
index 06586d6487e..ff0e9de9ec2 100644
--- a/configure.in
+++ b/configure.in
@@ -7,7 +7,7 @@ AC_INIT(sql/mysqld.cc)
 AC_CANONICAL_SYSTEM
 # The Docs Makefile.am parses this line!
 # remember to also change ndb version below and update version.c in ndb
-AM_INIT_AUTOMAKE(mysql, 5.0.76)
+AM_INIT_AUTOMAKE(mysql, 5.0.77)
 AM_CONFIG_HEADER([include/config.h:config.h.in])
 
 PROTOCOL_VERSION=10
@@ -23,7 +23,7 @@ NDB_SHARED_LIB_VERSION=$NDB_SHARED_LIB_MAJOR_VERSION:0:0
 # ndb version
 NDB_VERSION_MAJOR=5
 NDB_VERSION_MINOR=0
-NDB_VERSION_BUILD=76
+NDB_VERSION_BUILD=77
 NDB_VERSION_STATUS=""
 
 # Set all version vars based on $VERSION. How do we do this more elegant ?
diff --git a/mysql-test/r/greedy_optimizer.result b/mysql-test/r/greedy_optimizer.result
index 1da49fbedb0..534038ee626 100644
--- a/mysql-test/r/greedy_optimizer.result
+++ b/mysql-test/r/greedy_optimizer.result
@@ -655,3 +655,80 @@ show status like 'Last_query_cost';
 Variable_name	Value
 Last_query_cost	794.837037
 drop table t1,t2,t3,t4,t5,t6,t7;
+CREATE TABLE t1 (a int, b int, d int, i int);
+INSERT INTO t1 VALUES (1,1,1,1);
+CREATE TABLE t2 (b int, c int, j int);
+INSERT INTO t2 VALUES (1,1,1);
+CREATE TABLE t2_1 (j int);
+INSERT INTO t2_1 VALUES (1);
+CREATE TABLE t3 (c int, f int);
+INSERT INTO t3 VALUES (1,1);
+CREATE TABLE t3_1 (f int);
+INSERT INTO t3_1 VALUES (1);
+CREATE TABLE t4 (d int, e int, k int);
+INSERT INTO t4 VALUES (1,1,1);
+CREATE TABLE t4_1 (k int);
+INSERT INTO t4_1 VALUES (1);
+CREATE TABLE t5 (g int, d int, h int, l int);
+INSERT INTO t5 VALUES (1,1,1,1);
+CREATE TABLE t5_1 (l int);
+INSERT INTO t5_1 VALUES (1);
+SET optimizer_search_depth = 3;
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 LEFT JOIN (t3 JOIN t3_1 ON t3.f = t3_1.f) ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+(t2 JOIN t2_1 ON t2.j = t2_1.j) JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+(t4 JOIN t4_1 ON t4.k = t4_1.k) LEFT JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 LEFT JOIN (t5 JOIN t5_1 ON t5.l = t5_1.l) ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SET optimizer_search_depth = DEFAULT;
+DROP TABLE t1,t2,t2_1,t3,t3_1,t4,t4_1,t5,t5_1;
+End of 5.0 tests
diff --git a/mysql-test/r/having.result b/mysql-test/r/having.result
index f113304c767..bc8596100f8 100644
--- a/mysql-test/r/having.result
+++ b/mysql-test/r/having.result
@@ -424,3 +424,10 @@ select f1 from t1 group by f1 having max(f1)=f1;
 f1
 set session sql_mode='';
 drop table t1;
+CREATE TABLE t1 ( a INT, b INT);
+INSERT INTO t1 VALUES (1, 1), (2,2), (3, NULL);
+SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
+b	COUNT(DISTINCT a)
+NULL	1
+DROP TABLE t1;
+End of 5.0 tests
diff --git a/mysql-test/r/innodb_cache.result b/mysql-test/r/innodb_cache.result
index 5e8611655a2..36fa3c5c352 100644
--- a/mysql-test/r/innodb_cache.result
+++ b/mysql-test/r/innodb_cache.result
@@ -66,10 +66,10 @@ a
 2
 show status like "Qcache_queries_in_cache";
 Variable_name	Value
-Qcache_queries_in_cache	3
+Qcache_queries_in_cache	6
 show status like "Qcache_hits";
 Variable_name	Value
-Qcache_hits	3
+Qcache_hits	0
 insert into t1 values (3);
 insert into t2 values (3);
 insert into t1 values (4);
@@ -90,14 +90,14 @@ a
 2
 show status like "Qcache_queries_in_cache";
 Variable_name	Value
-Qcache_queries_in_cache	1
+Qcache_queries_in_cache	2
 show status like "Qcache_hits";
 Variable_name	Value
-Qcache_hits	4
+Qcache_hits	1
 commit;
 show status like "Qcache_queries_in_cache";
 Variable_name	Value
-Qcache_queries_in_cache	1
+Qcache_queries_in_cache	2
 drop table t3,t2,t1;
 CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY  (id)) ENGINE=InnoDB;
 select count(*) from t1;
diff --git a/mysql-test/r/not_embedded_server.result b/mysql-test/r/not_embedded_server.result
index e471b5a3afa..edb698ade83 100644
--- a/mysql-test/r/not_embedded_server.result
+++ b/mysql-test/r/not_embedded_server.result
@@ -3,3 +3,10 @@ execute stmt1;
 Id	User	Host	db	Command	Time	State	Info
 number	root	localhost	test	Query	time	NULL	show full processlist
 deallocate prepare stmt1;
+FLUSH STATUS;
+SHOW GLOBAL STATUS LIKE 'com_select';
+Variable_name	Value
+Com_select	101
+SHOW GLOBAL STATUS LIKE 'com_select';
+Variable_name	Value
+Com_select	101
diff --git a/mysql-test/r/query_cache.result b/mysql-test/r/query_cache.result
index fa80a44c177..a2b73db77a9 100644
--- a/mysql-test/r/query_cache.result
+++ b/mysql-test/r/query_cache.result
@@ -1681,3 +1681,54 @@ Qcache_hits	1
 DROP TABLE t1;
 SET GLOBAL concurrent_insert= @save_concurrent_insert;
 SET GLOBAL query_cache_size= default;
+DROP TABLE IF EXISTS t1;
+FLUSH STATUS;
+SET GLOBAL query_cache_size=1048576;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5);
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	0
+SELECT * FROM t1;
+a
+1
+2
+3
+4
+5
+BEGIN;
+SELECT * FROM t1;
+a
+1
+2
+3
+4
+5
+COMMIT;
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	2
+SHOW STATUS LIKE "Qcache_hits";
+Variable_name	Value
+Qcache_hits	0
+SELECT * FROM t1;
+a
+1
+2
+3
+4
+5
+BEGIN;
+SELECT * FROM t1;
+a
+1
+2
+3
+4
+5
+COMMIT;
+SHOW STATUS LIKE "Qcache_hits";
+Variable_name	Value
+Qcache_hits	2
+DROP TABLE t1;
+SET GLOBAL query_cache_size= default;
diff --git a/mysql-test/r/query_cache_notembedded.result b/mysql-test/r/query_cache_notembedded.result
index 8e5df012cfb..bf582bfaec6 100644
--- a/mysql-test/r/query_cache_notembedded.result
+++ b/mysql-test/r/query_cache_notembedded.result
@@ -345,3 +345,19 @@ id
 drop table t1;
 drop function f1;
 set GLOBAL query_cache_size=0;
+DROP TABLE IF EXISTS t1;
+FLUSH STATUS;
+SET GLOBAL query_cache_size=1048576;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5);
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	0
+LOCK TABLES t1 WRITE;
+SELECT * FROM t1;
+UNLOCK TABLES;
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	0
+DROP TABLE t1;
+SET GLOBAL query_cache_size= default;
diff --git a/mysql-test/t/greedy_optimizer.test b/mysql-test/t/greedy_optimizer.test
index b73f70c6a3e..5131c97f122 100644
--- a/mysql-test/t/greedy_optimizer.test
+++ b/mysql-test/t/greedy_optimizer.test
@@ -311,3 +311,76 @@ explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and
 show status like 'Last_query_cost';
 
 drop table t1,t2,t3,t4,t5,t6,t7;
+
+
+#
+# Bug # 38795: Automatic search depth and nested join's results in server
+# crash
+#
+
+CREATE TABLE t1 (a int, b int, d int, i int); INSERT INTO t1 VALUES (1,1,1,1);
+CREATE TABLE t2 (b int, c int, j int); INSERT INTO t2 VALUES (1,1,1);
+CREATE TABLE t2_1 (j int); INSERT INTO t2_1 VALUES (1);
+CREATE TABLE t3 (c int, f int); INSERT INTO t3 VALUES (1,1);
+CREATE TABLE t3_1 (f int); INSERT INTO t3_1 VALUES (1);
+CREATE TABLE t4 (d int, e int, k int); INSERT INTO t4 VALUES (1,1,1);
+CREATE TABLE t4_1 (k int); INSERT INTO t4_1 VALUES (1);
+CREATE TABLE t5 (g int, d int, h int, l int); INSERT INTO t5 VALUES (1,1,1,1);
+CREATE TABLE t5_1 (l int); INSERT INTO t5_1 VALUES (1);
+
+SET optimizer_search_depth = 3;
+
+SELECT 1
+FROM t1
+LEFT JOIN (
+  t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+  t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+
+SELECT 1
+FROM t1
+LEFT JOIN (
+  t2 LEFT JOIN (t3 JOIN t3_1 ON t3.f = t3_1.f) ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+  t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+
+SELECT 1
+FROM t1
+LEFT JOIN (
+ (t2 JOIN t2_1 ON t2.j = t2_1.j) JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+  t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+
+SELECT 1
+FROM t1
+LEFT JOIN (
+  t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+  (t4 JOIN t4_1 ON t4.k = t4_1.k) LEFT JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+
+SELECT 1
+FROM t1
+LEFT JOIN (
+  t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+  t4 LEFT JOIN (t5 JOIN t5_1 ON t5.l = t5_1.l) ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+
+SET optimizer_search_depth = DEFAULT;
+DROP TABLE t1,t2,t2_1,t3,t3_1,t4,t4_1,t5,t5_1;
+
+--echo End of 5.0 tests
diff --git a/mysql-test/t/having.test b/mysql-test/t/having.test
index 827b83f11a0..adabbb711d4 100644
--- a/mysql-test/t/having.test
+++ b/mysql-test/t/having.test
@@ -432,3 +432,14 @@ select f1 from t1 having max(f1)=f1;
 select f1 from t1 group by f1 having max(f1)=f1;
 set session sql_mode='';
 drop table t1;
+
+
+#
+# Bug #38637: COUNT DISTINCT prevents NULL testing in HAVING clause
+#
+CREATE TABLE t1 ( a INT, b INT);
+INSERT INTO t1 VALUES (1, 1), (2,2), (3, NULL);
+SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
+DROP TABLE t1;
+
+--echo End of 5.0 tests
diff --git a/mysql-test/t/not_embedded_server.test b/mysql-test/t/not_embedded_server.test
index 83ec03d6706..044d8665a18 100644
--- a/mysql-test/t/not_embedded_server.test
+++ b/mysql-test/t/not_embedded_server.test
@@ -16,3 +16,31 @@ execute stmt1;
 deallocate prepare stmt1;
 
 # End of 4.1 tests
+
+#
+# Bug#31222: com_% global status counters behave randomly with
+# mysql_change_user.
+#
+
+FLUSH STATUS;
+
+--disable_result_log
+--disable_query_log
+
+let $i = 100;
+
+while ($i)
+{
+  dec $i;
+
+  SELECT 1;
+}
+
+--enable_query_log
+--enable_result_log
+
+SHOW GLOBAL STATUS LIKE 'com_select';
+
+--change_user
+
+SHOW GLOBAL STATUS LIKE 'com_select';
diff --git a/mysql-test/t/query_cache.test b/mysql-test/t/query_cache.test
index ebd24bf2b89..2dd70f415a1 100644
--- a/mysql-test/t/query_cache.test
+++ b/mysql-test/t/query_cache.test
@@ -1276,4 +1276,31 @@ DROP TABLE t1;
 SET GLOBAL concurrent_insert= @save_concurrent_insert;
 SET GLOBAL query_cache_size= default;
 
+#
+# Bug#36326: nested transaction and select
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+FLUSH STATUS;
+SET GLOBAL query_cache_size=1048576;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5);
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+SELECT * FROM t1;
+BEGIN;
+SELECT * FROM t1;
+COMMIT;
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+SHOW STATUS LIKE "Qcache_hits";
+SELECT * FROM t1;
+BEGIN;
+SELECT * FROM t1;
+COMMIT;
+SHOW STATUS LIKE "Qcache_hits";
+DROP TABLE t1;
+SET GLOBAL query_cache_size= default;
+
 # End of 5.0 tests
diff --git a/mysql-test/t/query_cache_notembedded.test b/mysql-test/t/query_cache_notembedded.test
index a4f4144d9c6..c427e0d1afc 100644
--- a/mysql-test/t/query_cache_notembedded.test
+++ b/mysql-test/t/query_cache_notembedded.test
@@ -222,3 +222,34 @@ disconnect con2;
 connection default;
 
 set GLOBAL query_cache_size=0;
+
+#
+# Bug#40264: Aborted cached query causes query to hang indefinitely on next cache hit
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+FLUSH STATUS;
+SET GLOBAL query_cache_size=1048576;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5);
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+LOCK TABLES t1 WRITE;
+connect(con1,localhost,root,,);
+--send SELECT * FROM t1
+connection default;
+let $show_type= open tables where `table`='t1' and in_use=2;
+let $show_pattern= '%t1%2%';
+--source include/wait_show_pattern.inc
+dirty_close con1;
+UNLOCK TABLES;
+let $show_type= open tables where `table`='t1' and in_use=0;
+let $show_pattern= '%t1%0%';
+--source include/wait_show_pattern.inc
+SHOW STATUS LIKE 'Qcache_queries_in_cache';
+DROP TABLE t1;
+SET GLOBAL query_cache_size= default;
+
+# End of 5.0 tests
diff --git a/sql/item.cc b/sql/item.cc
index 2a89c86cd88..b67639d70b2 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -2041,6 +2041,12 @@ bool Item_field::val_bool_result()
 }
 
 
+bool Item_field::is_null_result()
+{
+  return (null_value=result_field->is_null());
+}
+
+
 bool Item_field::eq(const Item *item, bool binary_cmp) const
 {
   Item *real_item= ((Item *) item)->real_item();
@@ -5629,6 +5635,15 @@ double Item_ref::val_result()
 }
 
 
+bool Item_ref::is_null_result()
+{
+  if (result_field)
+    return (null_value=result_field->is_null());
+
+  return is_null();
+}
+
+
 longlong Item_ref::val_int_result()
 {
   if (result_field)
@@ -5734,7 +5749,9 @@ String *Item_ref::val_str(String* tmp)
 bool Item_ref::is_null()
 {
   DBUG_ASSERT(fixed);
-  return (*ref)->is_null();
+  bool tmp=(*ref)->is_null_result();
+  null_value=(*ref)->null_value;
+  return tmp;
 }
 
 
diff --git a/sql/item.h b/sql/item.h
index 250bb3f67ef..1058cc5dbb8 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -652,6 +652,7 @@ public:
   virtual my_decimal *val_decimal_result(my_decimal *val)
   { return val_decimal(val); }
   virtual bool val_bool_result() { return val_bool(); }
+  virtual bool is_null_result() { return is_null(); }
 
   /* bit map of tables used by item */
   virtual table_map used_tables() const { return (table_map) 0L; }
@@ -1301,6 +1302,7 @@ public:
   String *str_result(String* tmp);
   my_decimal *val_decimal_result(my_decimal *);
   bool val_bool_result();
+  bool is_null_result();
   bool send(Protocol *protocol, String *str_arg);
   void reset_field(Field *f);
   bool fix_fields(THD *, Item **);
@@ -1942,6 +1944,7 @@ public:
   String *str_result(String* tmp);
   my_decimal *val_decimal_result(my_decimal *);
   bool val_bool_result();
+  bool is_null_result();
   bool send(Protocol *prot, String *tmp);
   void make_field(Send_field *field);
   bool fix_fields(THD *, Item **);
diff --git a/sql/item_func.cc b/sql/item_func.cc
index c0d08d9b213..913b32ccb88 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -4285,6 +4285,15 @@ my_decimal *Item_func_set_user_var::val_decimal_result(my_decimal *val)
 }
 
 
+bool Item_func_set_user_var::is_null_result()
+{
+  DBUG_ASSERT(fixed == 1);
+  check(TRUE);
+  update();					// Store expression
+  return is_null();
+}
+
+
 void Item_func_set_user_var::print(String *str)
 {
   str->append(STRING_WITH_LEN("(@"));
diff --git a/sql/item_func.h b/sql/item_func.h
index 89c841abb75..7e15a536cf2 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -1302,6 +1302,7 @@ public:
   longlong val_int_result();
   String *str_result(String *str);
   my_decimal *val_decimal_result(my_decimal *);
+  bool is_null_result();
   bool update_hash(void *ptr, uint length, enum Item_result type,
   		   CHARSET_INFO *cs, Derivation dv, bool unsigned_arg);
   bool send(Protocol *protocol, String *str_arg);
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 8a8513ac745..b855af9a8d3 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -651,6 +651,8 @@ struct Query_cache_query_flags
   unsigned int client_long_flag:1;
   unsigned int client_protocol_41:1;
   unsigned int more_results_exists:1;
+  unsigned int in_trans:1;
+  unsigned int autocommit:1;
   unsigned int pkt_nr;
   uint character_set_client_num;
   uint character_set_results_num;
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
index b487f092f75..b55fa148e24 100644
--- a/sql/sql_cache.cc
+++ b/sql/sql_cache.cc
@@ -710,7 +710,12 @@ void query_cache_end_of_result(THD *thd)
   if (thd->net.query_cache_query == 0)
     DBUG_VOID_RETURN;
 
-  if (thd->killed)
+  /*
+    Check if the NET layer raised a unreported error -- my_error() and
+    as a consequence query_cache_abort() haven't been called. Abort the
+    cached result as it might be only partially complete.
+  */
+  if (thd->killed || thd->net.report_error)
   {
     query_cache_abort(&thd->net);
     DBUG_VOID_RETURN;
@@ -859,6 +864,8 @@ void Query_cache::store_query(THD *thd, TABLE_LIST *tables_used)
                                    CLIENT_PROTOCOL_41);
     flags.more_results_exists= test(thd->server_status &
                                     SERVER_MORE_RESULTS_EXISTS);
+    flags.in_trans= test(thd->server_status & SERVER_STATUS_IN_TRANS);
+    flags.autocommit= test(thd->server_status & SERVER_STATUS_AUTOCOMMIT);
     flags.pkt_nr= net->pkt_nr;
     flags.character_set_client_num=
       thd->variables.character_set_client->number;
@@ -879,7 +886,7 @@ void Query_cache::store_query(THD *thd, TABLE_LIST *tables_used)
     DBUG_PRINT("qcache", ("long %d, 4.1: %d, more results %d, pkt_nr: %d, \
 CS client: %u, CS result: %u, CS conn: %u, limit: %lu, TZ: 0x%lx, \
 sql mode: 0x%lx, sort len: %lu, conncat len: %lu, div_precision: %lu, \
-def_week_frmt: %lu",                          
+def_week_frmt: %lu, in_trans: %d, autocommit: %d",
                           (int)flags.client_long_flag,
                           (int)flags.client_protocol_41,
                           (int)flags.more_results_exists,
@@ -893,7 +900,10 @@ def_week_frmt: %lu",
                           flags.max_sort_length,
                           flags.group_concat_max_len,
                           flags.div_precision_increment,
-                          flags.default_week_format));
+                          flags.default_week_format,
+                          (int)flags.in_trans,
+                          (int)flags.autocommit));
+
     /*
      Make InnoDB to release the adaptive hash index latch before
      acquiring the query cache mutex.
@@ -1144,6 +1154,8 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length)
                                  CLIENT_PROTOCOL_41);
   flags.more_results_exists= test(thd->server_status &
                                   SERVER_MORE_RESULTS_EXISTS);
+  flags.in_trans= test(thd->server_status & SERVER_STATUS_IN_TRANS);
+  flags.autocommit= test(thd->server_status & SERVER_STATUS_AUTOCOMMIT);
   flags.pkt_nr= thd->net.pkt_nr;
   flags.character_set_client_num= thd->variables.character_set_client->number;
   flags.character_set_results_num=
@@ -1162,7 +1174,7 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length)
   DBUG_PRINT("qcache", ("long %d, 4.1: %d, more results %d, pkt_nr: %d, \
 CS client: %u, CS result: %u, CS conn: %u, limit: %lu, TZ: 0x%lx, \
 sql mode: 0x%lx, sort len: %lu, conncat len: %lu, div_precision: %lu, \
-def_week_frmt: %lu",                          
+def_week_frmt: %lu, in_trans: %d, autocommit: %d",
                           (int)flags.client_long_flag,
                           (int)flags.client_protocol_41,
                           (int)flags.more_results_exists,
@@ -1176,7 +1188,9 @@ def_week_frmt: %lu",
                           flags.max_sort_length,
                           flags.group_concat_max_len,
                           flags.div_precision_increment,
-                          flags.default_week_format));
+                          flags.default_week_format,
+                          (int)flags.in_trans,
+                          (int)flags.autocommit));
   memcpy((void *)(sql + (tot_length - QUERY_CACHE_FLAGS_SIZE)),
 	 &flags, QUERY_CACHE_FLAGS_SIZE);
   query_block = (Query_cache_block *)  hash_search(&queries, (byte*) sql,
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 883291ec460..91c0aa66761 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -391,6 +391,10 @@ void THD::init_for_queries()
 
 void THD::change_user(void)
 {
+  pthread_mutex_lock(&LOCK_status);
+  add_to_status(&global_status_var, &status_var);
+  pthread_mutex_unlock(&LOCK_status);
+
   cleanup();
   cleanup_done= 0;
   init();
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 230b9bb36cf..53e24414f01 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -100,7 +100,7 @@ static COND* substitute_for_best_equal_field(COND *cond,
                                              void *table_join_idx);
 static COND *simplify_joins(JOIN *join, List<TABLE_LIST> *join_list,
                             COND *conds, bool top);
-static bool check_interleaving_with_nj(JOIN_TAB *last, JOIN_TAB *next);
+static bool check_interleaving_with_nj(JOIN_TAB *next);
 static void restore_prev_nj_state(JOIN_TAB *last);
 static void reset_nj_counters(List<TABLE_LIST> *join_list);
 static uint build_bitmap_for_nested_joins(List<TABLE_LIST> *join_list,
@@ -4718,6 +4718,18 @@ greedy_search(JOIN      *join,
     */
     join->positions[idx]= best_pos;
 
+    /*
+      Update the interleaving state after extending the current partial plan
+      with a new table.
+      We are doing this here because best_extension_by_limited_search reverts
+      the interleaving state to the one of the non-extended partial plan 
+      on exit.
+    */
+    IF_DBUG(bool is_interleave_error= )
+    check_interleaving_with_nj (best_table);
+    /* This has been already checked by best_extension_by_limited_search */
+    DBUG_ASSERT(!is_interleave_error);
+
     /* find the position of 'best_table' in 'join->best_ref' */
     best_idx= idx;
     JOIN_TAB *pos= join->best_ref[best_idx];
@@ -4735,7 +4747,7 @@ greedy_search(JOIN      *join,
     --size_remain;
     ++idx;
 
-    DBUG_EXECUTE("opt", print_plan(join, join->tables,
+    DBUG_EXECUTE("opt", print_plan(join, idx,
                                    record_count, read_time, read_time,
                                    "extended"););
   } while (TRUE);
@@ -4886,7 +4898,7 @@ best_extension_by_limited_search(JOIN      *join,
     table_map real_table_bit= s->table->map;
     if ((remaining_tables & real_table_bit) && 
         !(remaining_tables & s->dependent) && 
-        (!idx || !check_interleaving_with_nj(join->positions[idx-1].table, s)))
+        (!idx || !check_interleaving_with_nj(s)))
     {
       double current_record_count, current_read_time;
 
@@ -5031,7 +5043,7 @@ find_best(JOIN *join,table_map rest_tables,uint idx,double record_count,
   {
     table_map real_table_bit=s->table->map;
     if ((rest_tables & real_table_bit) && !(rest_tables & s->dependent) &&
-        (!idx|| !check_interleaving_with_nj(join->positions[idx-1].table, s)))
+        (!idx|| !check_interleaving_with_nj(s)))
     {
       double records, best;
       best_access_path(join, s, thd, rest_tables, idx, record_count, 
@@ -8403,9 +8415,6 @@ static void reset_nj_counters(List<TABLE_LIST> *join_list)
 
   SYNOPSIS
     check_interleaving_with_nj()
-      join       Join being processed
-      last_tab   Last table in current partial join order (this function is
-                 not called for empty partial join orders)
       next_tab   Table we're going to extend the current partial join with
 
   DESCRIPTION
@@ -8490,10 +8499,10 @@ static void reset_nj_counters(List<TABLE_LIST> *join_list)
     TRUE   Requested join order extension not allowed.
 */
 
-static bool check_interleaving_with_nj(JOIN_TAB *last_tab, JOIN_TAB *next_tab)
+static bool check_interleaving_with_nj(JOIN_TAB *next_tab)
 {
   TABLE_LIST *next_emb= next_tab->table->pos_in_table_list->embedding;
-  JOIN *join= last_tab->join;
+  JOIN *join= next_tab->join;
 
   if (join->cur_embedding_map & ~next_tab->embedding_map)
   {
diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 50f03a1a086..0fddffebf82 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -16354,6 +16354,63 @@ static void test_bug40365(void)
 
   DBUG_VOID_RETURN;
 }
+
+
+/**
+  Bug#36326: nested transaction and select
+*/
+
+#ifdef HAVE_QUERY_CACHE
+
+static void test_bug36326()
+{
+  int rc;
+
+  DBUG_ENTER("test_bug36326");
+  myheader("test_bug36326");
+
+  rc= mysql_autocommit(mysql, TRUE);
+  myquery(rc);
+  rc= mysql_query(mysql, "DROP TABLE IF EXISTS t1");
+  myquery(rc);
+  rc= mysql_query(mysql, "CREATE  TABLE t1 (a INTEGER)");
+  myquery(rc);
+  rc= mysql_query(mysql, "INSERT INTO t1 VALUES (1)");
+  myquery(rc);
+  rc= mysql_query(mysql, "SET GLOBAL query_cache_type = 1");
+  myquery(rc);
+  rc= mysql_query(mysql, "SET GLOBAL query_cache_size = 1048576");
+  myquery(rc);
+  DIE_UNLESS(!(mysql->server_status & SERVER_STATUS_IN_TRANS));
+  DIE_UNLESS(mysql->server_status & SERVER_STATUS_AUTOCOMMIT);
+  rc= mysql_query(mysql, "BEGIN");
+  myquery(rc);
+  DIE_UNLESS(mysql->server_status & SERVER_STATUS_IN_TRANS);
+  rc= mysql_query(mysql, "SELECT * FROM t1");
+  myquery(rc);
+  rc= my_process_result(mysql);
+  DIE_UNLESS(rc == 1);
+  rc= mysql_rollback(mysql);
+  myquery(rc);
+  rc= mysql_query(mysql, "ROLLBACK");
+  myquery(rc);
+  DIE_UNLESS(!(mysql->server_status & SERVER_STATUS_IN_TRANS));
+  rc= mysql_query(mysql, "SELECT * FROM t1");
+  myquery(rc);
+  DIE_UNLESS(!(mysql->server_status & SERVER_STATUS_IN_TRANS));
+  rc= my_process_result(mysql);
+  DIE_UNLESS(rc == 1);
+  rc= mysql_query(mysql, "DROP TABLE t1");
+  myquery(rc);
+  rc= mysql_query(mysql, "SET GLOBAL query_cache_size = 0");
+  myquery(rc);
+
+  DBUG_VOID_RETURN;
+}
+
+#endif
+
+
 /*
   Read and parse arguments and MySQL options from my.cnf
 */
@@ -16652,6 +16709,9 @@ static struct my_tests_st my_tests[]= {
   { "test_bug40365", test_bug40365 },
 #ifdef HAVE_SPATIAL
   { "test_bug37956", test_bug37956 },
+#endif
+#ifdef HAVE_QUERY_CACHE
+  { "test_bug36326", test_bug36326 },
 #endif
   { 0, 0 }
 };