MDEV-7810 Wrong result on execution of a query as a PS (both 1st and further executions)

Alternative fix that doesn't cause view.test crash in --ps:
Remember when Item_ref was fixed right in the constructor
and did not have a full Item_ref::fix_fields() call. Later
in PS/SP, after Item_ref::cleanup, we use this knowledge
to avoid doing full fix_fields() for items that were never
supposed to be fix_field'ed.

Simplify the test case.

mysql-test/r/subselect_mat.result

@@ -2150,20 +2150,11 @@ drop database mysqltest4;
 # (both 1st and further executions)
 CREATE TABLE t1 (a INT NOT NULL) ENGINE=MyISAM;
 INSERT INTO t1 VALUES (0),(8);
-SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2;
-a
-0
-8
-SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a));
-MIN(t3.a)
-0
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) );
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2));
 a
 0
 PREPARE stmt FROM "
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) )
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2))
 ";
 execute stmt;
 a

mysql-test/r/subselect_sj_mat.result

@@ -2190,20 +2190,11 @@ drop database mysqltest4;
 # (both 1st and further executions)
 CREATE TABLE t1 (a INT NOT NULL) ENGINE=MyISAM;
 INSERT INTO t1 VALUES (0),(8);
-SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2;
-a
-0
-8
-SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a));
-MIN(t3.a)
-0
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) );
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2));
 a
 0
 PREPARE stmt FROM "
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) )
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2))
 ";
 execute stmt;
 a

mysql-test/t/subselect_sj_mat.test

@@ -1848,13 +1848,9 @@ drop database mysqltest4;
 CREATE TABLE t1 (a INT NOT NULL) ENGINE=MyISAM;
 INSERT INTO t1 VALUES (0),(8);
 
-SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2;
-SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a));
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) );
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2));
 PREPARE stmt FROM "
-SELECT a FROM ( SELECT DISTINCT t9.* FROM t1 AS t9, t1 AS t2 ) AS sq 
-WHERE a IN ( SELECT MIN(t3.a) FROM ( t1 AS t3 INNER JOIN t1 AS t4 ON (t3.a = t4.a) ) )
+SELECT a FROM (SELECT DISTINCT * FROM t1) AS sq WHERE a IN (SELECT MIN(t2.a) FROM (t1 AS t2))
 ";
 execute stmt;
 execute stmt;

sql/item.cc

@@ -6754,7 +6754,7 @@ Item_ref::Item_ref(Name_resolution_context *context_arg,
   /*
     This constructor used to create some internals references over fixed items
   */
-  if (ref && *ref && (*ref)->fixed)
+  if ((set_properties_only= (ref && *ref && (*ref)->fixed)))
     set_properties();
 }
 
@@ -6798,7 +6798,7 @@ Item_ref::Item_ref(TABLE_LIST *view_arg, Item **item,
   /*
     This constructor is used to create some internal references over fixed items
   */
-  if (ref && *ref && (*ref)->fixed)
+  if ((set_properties_only= (ref && *ref && (*ref)->fixed)))
     set_properties();
 }
 
@@ -6873,7 +6873,11 @@ bool Item_ref::fix_fields(THD *thd, Item **reference)
   DBUG_ASSERT(fixed == 0);
   SELECT_LEX *current_sel= thd->lex->current_select;
 
-  if (!ref || ref == not_found_item)
+  if (set_properties_only)
+  {
+    /* do nothing */
+  }
+  else if (!ref || ref == not_found_item)
   {
     DBUG_ASSERT(reference_trough_name != 0);
     if (!(ref= resolve_ref_in_select_and_group(thd, this,

sql/item.h

@@ -2946,6 +2946,7 @@ class Item_ref :public Item_ident
 {
 protected:
   void set_properties();
+  bool set_properties_only; // the item doesn't need full fix_fields
 public:
   enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF, AGGREGATE_REF };
   Field *result_field;			 /* Save result here */
@@ -2955,7 +2956,7 @@ public:
            const char *db_arg, const char *table_name_arg,
            const char *field_name_arg)
     :Item_ident(context_arg, db_arg, table_name_arg, field_name_arg),
-    result_field(0), ref(0), reference_trough_name(1) {}
+    set_properties_only(0), result_field(0), ref(0), reference_trough_name(1) {}
   /*
     This constructor is used in two scenarios:
     A) *item = NULL
@@ -2978,7 +2979,7 @@ public:
 
   /* Constructor need to process subselect with temporary tables (see Item) */
   Item_ref(THD *thd, Item_ref *item)
-    :Item_ident(thd, item), result_field(item->result_field), ref(item->ref) {}
+    :Item_ident(thd, item), set_properties_only(0), result_field(item->result_field), ref(item->ref) {}
   enum Type type() const		{ return REF_ITEM; }
   enum Type real_type() const           { return ref ? (*ref)->type() :
                                           REF_ITEM; }

sql/item_subselect.cc

@@ -2007,37 +2007,6 @@ Item_in_subselect::create_single_in_to_exists_cond(JOIN *join,
   *where_item= NULL;
   *having_item= NULL;
 
-  /*
-    For PS we have to do fix_fields(expr) here to ensure that it's
-    evaluated in the outer context.  If not, then fix_having() will do
-    a fix_fields(expr) in the inner context and mark expr as
-    'depended', which will cause update_ref_and_keys() to find wrong
-    keys.
-    When not running PS, fix_fields(expr) as already been done earlier and
-    the following test does nothing.
-  */
-  if (expr && !expr->fixed)
-  {
-    bool tmp;
-    SELECT_LEX *save_current_select= thd->lex->current_select;
-    Item_subselect *save_item;
-
-    thd->lex->current_select= thd->lex->current_select->outer_select();
-    /*
-      For st_select_lex::mark_as_dependent, who needs to mark
-      this sub query as correlated.
-    */
-    save_item= thd->lex->current_select->master_unit()->item;
-    thd->lex->current_select->master_unit()->item= this;
-
-    tmp= expr->fix_fields(thd, 0);
-
-    thd->lex->current_select->master_unit()->item= save_item;
-    thd->lex->current_select= save_current_select;
-    if (tmp)
-      DBUG_RETURN(true);
-  }
-
   if (join_having || select_lex->with_sum_func ||
       select_lex->group_list.elements)
   {

sql/sql_base.cc

@@ -6936,6 +6936,8 @@ find_field_in_tables(THD *thd, Item_ident *item,
       return found;
     }
   }
+  else
+    item->can_be_depended= TRUE;
 
   if (db && lower_case_table_names)
   {