Applied Sanja's patch to fix LP bug #784297 in the tree for mwl106.

The patch imposes unconditional materialization for derived tables
used in update and multi-update statements.
Fixed a bug with a wrong order of processing derived tables/views
at the prepare stage that caused a crash for the variant of the 
query from test case for bug 52157.

mysql-test/r/multi_update.result

@@ -654,6 +654,9 @@ INSERT INTO t3 VALUES (1), (2);
 UPDATE IGNORE
 ( SELECT ( SELECT COUNT(*) FROM t1 GROUP BY a, @v ) a FROM t2 ) x, t3
 SET t3.a = 0;
+Warnings:
+Error	1242	Subquery returns more than 1 row
+Error	1242	Subquery returns more than 1 row
 DROP TABLE t1, t2, t3;
 SET SESSION sql_safe_updates = DEFAULT;
 #
@@ -662,6 +665,14 @@ SET SESSION sql_safe_updates = DEFAULT;
 CREATE FUNCTION f1 () RETURNS BLOB RETURN 1;
 CREATE TABLE t1 (f1 DATE);
 INSERT INTO t1 VALUES('2001-01-01');
+UPDATE (SELECT 1 FROM t1 WHERE f1 = (SELECT f1() FROM t1)) x, t1 SET f1 = 1;
+Warnings:
+Warning	1292	Truncated incorrect datetime value: '1'
+CREATE view v1 as SELECT f1() FROM t1;
+UPDATE (SELECT 1 FROM t1 WHERE f1 = (select * from v1)) x, t1 SET f1 = 1;
+Warnings:
+Warning	1292	Truncated incorrect datetime value: '1'
+DROP VIEW v1;
 DROP FUNCTION f1;
 DROP TABLE t1;
 end of tests

mysql-test/suite/innodb/r/innodb_multi_update.result

@@ -79,4 +79,6 @@ drop table bug38999_1,bug38999_2;
 #
 CREATE TABLE t1(f1 INT) ENGINE=INNODB;
 INSERT INTO t1 VALUES(1);
+UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
+ERROR 21000: Operand should contain 1 column(s)
 DROP TABLE t1;

mysql-test/suite/innodb/t/innodb_multi_update.test

@@ -34,9 +34,7 @@ drop table bug38999_1,bug38999_2;
 --echo #
 CREATE TABLE t1(f1 INT) ENGINE=INNODB;
 INSERT INTO t1 VALUES(1);
-# !!! This query returns a wrong error due to a bug in the code of mwl106
-# !!! Uncomment it when the bug is fixed
-# --error ER_OPERAND_COLUMNS
-# UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
+--error ER_OPERAND_COLUMNS
+UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
 DROP TABLE t1;
 

mysql-test/suite/innodb_plugin/r/innodb_multi_update.result

@@ -79,4 +79,6 @@ drop table bug38999_1,bug38999_2;
 #
 CREATE TABLE t1(f1 INT) ENGINE=INNODB;
 INSERT INTO t1 VALUES(1);
+UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
+ERROR 21000: Operand should contain 1 column(s)
 DROP TABLE t1;

mysql-test/suite/innodb_plugin/t/innodb_multi_update.test

@@ -34,9 +34,7 @@ drop table bug38999_1,bug38999_2;
 --echo #
 CREATE TABLE t1(f1 INT) ENGINE=INNODB;
 INSERT INTO t1 VALUES(1);
-# !!! This query returns a wrong error due to a bug in the code of mwl106
-# !!! Uncomment it when the bug is fixed
-# --error ER_OPERAND_COLUMNS
-# UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
+--error ER_OPERAND_COLUMNS
+UPDATE (SELECT ((SELECT 1 FROM t1), 1) FROM t1 WHERE (SELECT 1 FROM t1)) x, (SELECT 1) AS d SET d.f1 = 1;
 DROP TABLE t1;
 

mysql-test/t/multi_update.test

@@ -684,9 +684,10 @@ SET SESSION sql_safe_updates = DEFAULT;
 CREATE FUNCTION f1 () RETURNS BLOB RETURN 1;
 CREATE TABLE t1 (f1 DATE);
 INSERT INTO t1 VALUES('2001-01-01');
-# !!! This query returns a wrong error due to a bug in the code of mwl106
-# !!! Uncomment it when the bug is fixed
-# UPDATE (SELECT 1 FROM t1 WHERE f1 = (SELECT f1() FROM t1)) x, t1 SET f1 = 1;
+UPDATE (SELECT 1 FROM t1 WHERE f1 = (SELECT f1() FROM t1)) x, t1 SET f1 = 1;
+CREATE view v1 as SELECT f1() FROM t1;
+UPDATE (SELECT 1 FROM t1 WHERE f1 = (select * from v1)) x, t1 SET f1 = 1;
+DROP VIEW v1;
 DROP FUNCTION f1;
 DROP TABLE t1;
 

sql/sql_lex.h

@@ -585,6 +585,8 @@ class st_select_lex_unit: public st_select_lex_node {
   void set_thd(THD *thd_arg) { thd= thd_arg; }
   inline bool is_union (); 
 
+  void set_unique_exlude();
+
   friend void lex_start(THD *thd);
   friend int subselect_union_engine::exec();
 

sql/sql_union.cc

@@ -944,3 +944,27 @@ void st_select_lex::cleanup_all_joins(bool full)
     for (sl= unit->first_select(); sl; sl= sl->next_select())
       sl->cleanup_all_joins(full);
 }
+
+
+/**
+  Set exclude_from_table_unique_test for selects of this unit and all
+  underlying selects.
+
+  @note used to exclude materialized derived tables (views) from unique
+  table check.
+*/
+
+void st_select_lex_unit::set_unique_exlude()
+{
+  for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
+  {
+    sl->exclude_from_table_unique_test= TRUE;
+    for (SELECT_LEX_UNIT *unit= sl->first_inner_unit();
+         unit;
+         unit= unit->next_unit())
+    {
+      unit->set_unique_exlude();
+    }
+  }
+}
+

sql/sql_update.cc

@@ -1040,8 +1040,8 @@ int mysql_multi_update_prepare(THD *thd)
   //We need to merge for insert prior to prepare.
   if (mysql_handle_list_of_derived(lex, table_list, DT_MERGE_FOR_INSERT))
     DBUG_RETURN(1);
-  if  (mysql_handle_list_of_derived(lex, table_list, DT_PREPARE))
-    DBUG_RETURN(1);
+  if (mysql_handle_derived(lex, DT_PREPARE))
+    DBUG_RETURN(TRUE);
 
   if (setup_tables_and_check_access(thd, &lex->select_lex.context,
                                     &lex->select_lex.top_join_list,

sql/table.cc

@@ -5851,7 +5851,9 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view)
   if (!is_view())
   {
     /* A subquery might be forced to be materialized due to a side-effect. */
-    if (!is_materialized_derived() && first_select->is_mergeable())
+    if (!is_materialized_derived() && first_select->is_mergeable() &&
+        !(thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
+          thd->lex->sql_command == SQLCOM_UPDATE))
       set_merged_derived();
     else
       set_materialized_derived();
@@ -5862,9 +5864,7 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view)
   */
   if (is_materialized_derived())
   {
-    SELECT_LEX *sl;
-    for (sl= first_select ;sl ; sl= sl->next_select())
-      sl->exclude_from_table_unique_test= TRUE;
+    unit->master_unit()->set_unique_exlude();
   }
   /*
     Create field translation for mergeable derived tables/views.