Revert "MDEV-24454 Crash at change_item_tree"

This patch reverts the fixes of the bugs MDEV-24454 and MDEV-25631 from
the commit 3690c549c6e72646ba74f6b4c83813ee4ac3aea4.
It leaves the changes in plugin/feedback/feedback.cc and corresponding
test files introduced in this commit intact.

Proper fixes for the bug MDEV-24454 and MDEV-25631 will follow immediately.

8 files changed, 39 insertions, 173 deletions

diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index 001d26fc466..d278eb1f870 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -6833,49 +6833,6 @@ sum(z)
 DROP TABLE t1;
 DROP VIEW v1;
 #
-# MDEV-24454: Crash at change_item_tree
-#
-CREATE TABLE t1(f0 INT);
-CREATE VIEW v1 AS
-SELECT
-f0 AS f1
-FROM t1;
-CREATE VIEW v2 AS
-SELECT
-(SELECT GROUP_CONCAT(v1.f1 SEPARATOR ', ')
-FROM v1 n) AS f2,
-GROUP_CONCAT('' SEPARATOR ', ') AS f3
-FROM v1;
-CREATE VIEW v3 AS
-SELECT 1 as f4 FROM v2;
-CREATE PROCEDURE p1()
-SELECT * FROM v3;
-CALL p1();
-f4
-1
-CALL p1();
-f4
-1
-drop procedure p1;
-drop view v1,v2,v3;
-drop table t1;
-#
-# MDEV-25631: Crash in st_select_lex::mark_as_dependent with
-# VIEW, aggregate and subquery
-#
-CREATE TABLE t1 (i1 int);
-insert into t1 values (1),(2),(3);
-CREATE VIEW v1 AS
-SELECT t1.i1 FROM (t1 a JOIN t1 ON (t1.i1 = (SELECT t1.i1 FROM t1 b)));
-SELECT 1 FROM (SELECT count(((SELECT i1 FROM v1))) FROM v1) dt ;
-ERROR 21000: Subquery returns more than 1 row
-delete from t1 where i1 > 1;
-SELECT 1 FROM (SELECT count(((SELECT i1 FROM v1))) FROM v1) dt ;
-1
-1
-drop view v1;
-drop table t1;
-#
 # MDEV-26299: Some views force server (and mysqldump) to generate
 # invalid SQL for their definitions
 #
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index e6e6ccce8bd..4fb1806fac9 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -6560,56 +6560,6 @@ DROP TABLE t1;
 DROP VIEW v1;
 
 --echo #
---echo # MDEV-24454: Crash at change_item_tree
---echo #
-
-CREATE TABLE t1(f0 INT);
-
-CREATE VIEW v1 AS
-SELECT
-  f0 AS f1
-FROM t1;
-
-CREATE VIEW v2 AS
-SELECT
-  (SELECT GROUP_CONCAT(v1.f1 SEPARATOR ', ')
-   FROM v1 n) AS f2,
-  GROUP_CONCAT('' SEPARATOR ', ') AS f3
-FROM v1;
-
-CREATE VIEW v3 AS
-SELECT 1 as f4 FROM v2;
-
-CREATE PROCEDURE p1()
-  SELECT * FROM v3;
-
-CALL p1();
-CALL p1();
-
-drop procedure p1;
-drop view v1,v2,v3;
-drop table t1;
-
---echo #
---echo # MDEV-25631: Crash in st_select_lex::mark_as_dependent with
---echo # VIEW, aggregate and subquery
---echo #
-
-CREATE TABLE t1 (i1 int);
-insert into t1 values (1),(2),(3); #not important
-CREATE VIEW v1 AS
-	SELECT t1.i1 FROM (t1 a JOIN t1 ON (t1.i1 = (SELECT t1.i1 FROM t1 b)));
-
---error ER_SUBQUERY_NO_1_ROW
-SELECT 1 FROM (SELECT count(((SELECT i1 FROM v1))) FROM v1) dt ;
-delete from t1 where i1 > 1;
-SELECT 1 FROM (SELECT count(((SELECT i1 FROM v1))) FROM v1) dt ;
-
-drop view v1;
-drop table t1;
-
-
---echo #
 --echo # MDEV-26299: Some views force server (and mysqldump) to generate
 --echo # invalid SQL for their definitions
 --echo #
diff --git a/sql/item.cc b/sql/item.cc
index a5b313b786d..2317d54d3e5 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -61,12 +61,11 @@ bool cmp_items(Item *a, Item *b)
 /**
   Set max_sum_func_level if it is needed
 */
-inline void set_max_sum_func_level(SELECT_LEX *select)
+inline void set_max_sum_func_level(THD *thd, SELECT_LEX *select)
 {
-  LEX *lex_s= select->parent_lex;
-  if (lex_s->in_sum_func &&
-      lex_s->in_sum_func->nest_level >= select->nest_level)
-    set_if_bigger(lex_s->in_sum_func->max_sum_func_level,
+  if (thd->lex->in_sum_func &&
+      thd->lex->in_sum_func->nest_level >= select->nest_level)
+    set_if_bigger(thd->lex->in_sum_func->max_sum_func_level,
                   select->nest_level - 1);
 }
 
@@ -781,7 +780,6 @@ Item_ident::Item_ident(THD *thd, Name_resolution_context *context_arg,
 {
   name = (char*) field_name_arg;
   name_length= name ? strlen(name) : 0;
-  DBUG_ASSERT(!context || context->select_lex);
 }
 
 
@@ -796,7 +794,6 @@ Item_ident::Item_ident(THD *thd, TABLE_LIST *view_arg, const char *field_name_ar
 {
   name = (char*) field_name_arg;
   name_length= name ? strlen(name) : 0;
-  DBUG_ASSERT(!context || context->select_lex);
 }
 
 
@@ -818,9 +815,7 @@ Item_ident::Item_ident(THD *thd, Item_ident *item)
    cached_table(item->cached_table),
    depended_from(item->depended_from),
    can_be_depended(item->can_be_depended)
-{
-  DBUG_ASSERT(!context || context->select_lex);
-}
+{}
 
 void Item_ident::cleanup()
 {
@@ -5162,14 +5157,7 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
   */
   Name_resolution_context *last_checked_context= context;
   Item **ref= (Item **) not_found_item;
-  /*
-    There are cases when name resolution context is absent (when we are not
-    doing name resolution), but here the name resolution context should
-    be present because we are doing name resolution
-  */
-  DBUG_ASSERT(context);
-  SELECT_LEX *current_sel=  context->select_lex;
-  LEX *lex_s= context->select_lex->parent_lex;
+  SELECT_LEX *current_sel= thd->lex->current_select;
   Name_resolution_context *outer_context= 0;
   SELECT_LEX *select= 0;
   /* Currently derived tables cannot be correlated */
@@ -5270,18 +5258,18 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
               return -1;
             thd->change_item_tree(reference, rf);
             select->inner_refs_list.push_back(rf, thd->mem_root);
-            rf->in_sum_func= lex_s->in_sum_func;
+            rf->in_sum_func= thd->lex->in_sum_func;
           }
           /*
             A reference is resolved to a nest level that's outer or the same as
             the nest level of the enclosing set function : adjust the value of
             max_arg_level for the function if it's needed.
           */
-          if (lex_s->in_sum_func &&
-              lex_s->in_sum_func->nest_level >= select->nest_level)
+          if (thd->lex->in_sum_func &&
+              thd->lex->in_sum_func->nest_level >= select->nest_level)
           {
             Item::Type ref_type= (*reference)->type();
-            set_if_bigger(lex_s->in_sum_func->max_arg_level,
+            set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                           select->nest_level);
             set_field(*from_field);
             fixed= 1;
@@ -5302,10 +5290,10 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
                             ((ref_type == REF_ITEM || ref_type == FIELD_ITEM) ?
                              (Item_ident*) (*reference) :
                              0), false);
-          if (lex_s->in_sum_func &&
-              lex_s->in_sum_func->nest_level >= select->nest_level)
+          if (thd->lex->in_sum_func &&
+              thd->lex->in_sum_func->nest_level >= select->nest_level)
           {
-            set_if_bigger(lex_s->in_sum_func->max_arg_level,
+            set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                           select->nest_level);
           }
           /*
@@ -5397,7 +5385,7 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
     {
       outer_context->select_lex->inner_refs_list.push_back((Item_outer_ref*)rf,
                                                            thd->mem_root);
-      ((Item_outer_ref*)rf)->in_sum_func= lex_s->in_sum_func;
+      ((Item_outer_ref*)rf)->in_sum_func= thd->lex->in_sum_func;
     }
     thd->change_item_tree(reference, rf);
     /*
@@ -5412,7 +5400,7 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
       We can not "move" aggregate function in the place where
       its arguments are not defined.
     */
-    set_max_sum_func_level(select);
+    set_max_sum_func_level(thd, select);
     mark_as_dependent(thd, last_checked_context->select_lex,
                       context->select_lex, rf,
                       rf, false);
@@ -5425,7 +5413,7 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
       We can not "move" aggregate function in the place where
       its arguments are not defined.
     */
-    set_max_sum_func_level(select);
+    set_max_sum_func_level(thd, select);
     mark_as_dependent(thd, last_checked_context->select_lex,
                       context->select_lex,
                       this, (Item_ident*)*reference, false);
@@ -5502,20 +5490,7 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
   DBUG_ASSERT(fixed == 0);
   Field *from_field= (Field *)not_found_field;
   bool outer_fixed= false;
-  SELECT_LEX *select;
-  LEX *lex_s;
-  if (context)
-  {
-    select= context->select_lex;
-    lex_s= context->select_lex->parent_lex;
-  }
-  else
-  {
-    // No real name resolution, used somewhere in SP
-    DBUG_ASSERT(field);
-    select= NULL;
-    lex_s= NULL;
-  }
+  SELECT_LEX *select= thd->lex->current_select;
 
   if (!field)					// If field is not checked
   {
@@ -5576,7 +5551,7 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
               We can not "move" aggregate function in the place where
               its arguments are not defined.
             */
-            set_max_sum_func_level(select);
+            set_max_sum_func_level(thd, select);
             set_field(new_field);
             depended_from= (*((Item_field**)res))->depended_from;
             return 0;
@@ -5605,7 +5580,7 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
               We can not "move" aggregate function in the place where
               its arguments are not defined.
             */
-            set_max_sum_func_level(select);
+            set_max_sum_func_level(thd, select);
             return FALSE;
           }
         }
@@ -5642,11 +5617,10 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
         goto mark_non_agg_field;
     }
 
-    if (lex_s &&
-        lex_s->in_sum_func &&
-        lex_s->in_sum_func->nest_level ==
+    if (thd->lex->in_sum_func &&
+        thd->lex->in_sum_func->nest_level == 
         select->nest_level)
-      set_if_bigger(lex_s->in_sum_func->max_arg_level,
+      set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                     select->nest_level);
     /*
       if it is not expression from merged VIEW we will set this field.
@@ -5712,9 +5686,8 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
   if (field->vcol_info)
     fix_session_vcol_expr_for_read(thd, field, field->vcol_info);
   if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY &&
-      !outer_fixed &&
+      !outer_fixed && !thd->lex->in_sum_func &&
       select &&
-      !lex_s->in_sum_func &&
       select->cur_pos_in_select_list != UNDEF_POS &&
       select->join)
   {
@@ -5749,13 +5722,13 @@ mark_non_agg_field:
       */
       select_lex= context->select_lex;
     }
-    if (!lex_s || !lex_s->in_sum_func)
+    if (!thd->lex->in_sum_func)
       select_lex->set_non_agg_field_used(true);
     else
     {
       if (outer_fixed)
-        lex_s->in_sum_func->outer_fields.push_back(this, thd->mem_root);
-      else if (lex_s->in_sum_func->nest_level !=
+        thd->lex->in_sum_func->outer_fields.push_back(this, thd->mem_root);
+      else if (thd->lex->in_sum_func->nest_level !=
           select->nest_level)
         select_lex->set_non_agg_field_used(true);
     }
@@ -7248,12 +7221,6 @@ Item *get_field_item_for_having(THD *thd, Item *item, st_select_lex *sel)
   return NULL; 
 }
 
-Item *Item_ident::derived_field_transformer_for_having(THD *thd, uchar *arg)
-{
-  st_select_lex *sel= (st_select_lex *)arg;
-  context= &sel->context;
-  return this;
-}
 
 Item *Item_field::derived_field_transformer_for_having(THD *thd, uchar *arg)
 {
@@ -7273,13 +7240,12 @@ Item *Item_field::derived_field_transformer_for_having(THD *thd, uchar *arg)
 Item *Item_direct_view_ref::derived_field_transformer_for_having(THD *thd,
                                                                  uchar *arg)
 {
-  st_select_lex *sel= (st_select_lex *)arg;
-  context= &sel->context;
   if ((*ref)->marker & SUBSTITUTION_FL)
   {
     this->marker|= SUBSTITUTION_FL;
     return this;
   }
+  st_select_lex *sel= (st_select_lex *)arg;
   table_map tab_map= sel->master_unit()->derived->table->map;
   if ((item_equal && !(item_equal->used_tables() & tab_map)) ||
       !item_equal)
@@ -7575,9 +7541,7 @@ bool Item_ref::fix_fields(THD *thd, Item **reference)
 {
   enum_parsing_place place= NO_MATTER;
   DBUG_ASSERT(fixed == 0);
-
-  SELECT_LEX *current_sel= context->select_lex;
-  LEX *lex_s= context->select_lex->parent_lex;
+  SELECT_LEX *current_sel= thd->lex->current_select;
 
   if (set_properties_only)
   {
@@ -7738,10 +7702,10 @@ bool Item_ref::fix_fields(THD *thd, Item **reference)
           the nest level of the enclosing set function : adjust the value of
           max_arg_level for the function if it's needed.
         */
-        if (lex_s->in_sum_func &&
-            lex_s->in_sum_func->nest_level >=
+        if (thd->lex->in_sum_func &&
+            thd->lex->in_sum_func->nest_level >= 
             last_checked_context->select_lex->nest_level)
-          set_if_bigger(lex_s->in_sum_func->max_arg_level,
+          set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                         last_checked_context->select_lex->nest_level);
         return FALSE;
       }
@@ -7761,10 +7725,10 @@ bool Item_ref::fix_fields(THD *thd, Item **reference)
         the nest level of the enclosing set function : adjust the value of
         max_arg_level for the function if it's needed.
       */
-      if (lex_s->in_sum_func &&
-          lex_s->in_sum_func->nest_level >=
+      if (thd->lex->in_sum_func &&
+          thd->lex->in_sum_func->nest_level >= 
           last_checked_context->select_lex->nest_level)
-        set_if_bigger(lex_s->in_sum_func->max_arg_level,
+        set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                       last_checked_context->select_lex->nest_level);
     }
   }
diff --git a/sql/item.h b/sql/item.h
index 997352ef27a..086d85e989f 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -2630,7 +2630,6 @@ public:
     Collect outer references
   */
   virtual bool collect_outer_ref_processor(void *arg);
-  Item *derived_field_transformer_for_having(THD *thd, uchar *arg);
   friend bool insert_fields(THD *thd, Name_resolution_context *context,
                             const char *db_name,
                             const char *table_name, List_iterator<Item> *it,
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 3f9a760ce09..25621dfe104 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -5190,9 +5190,8 @@ bool subselect_hash_sj_engine::make_semi_join_conds()
                                 NULL, TL_READ);
   tmp_table_ref->table= tmp_table;
 
-  context= new (thd->mem_root) Name_resolution_context;
+  context= new Name_resolution_context;
   context->init();
-  context->select_lex= item_in->unit->first_select();
   context->first_name_resolution_table=
     context->last_name_resolution_table= tmp_table_ref;
   semi_join_conds_context= context;
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index f20be3b5226..dd65f04a652 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -68,7 +68,6 @@ size_t Item_sum::ram_limitation(THD *thd)
 bool Item_sum::init_sum_func_check(THD *thd)
 {
   SELECT_LEX *curr_sel= thd->lex->current_select;
-  LEX *lex_s= (curr_sel ? curr_sel->parent_lex : thd->lex);
   if (curr_sel && !curr_sel->name_visibility_map)
   {
     for (SELECT_LEX *sl= curr_sel; sl; sl= sl->context.outer_select())
@@ -83,9 +82,9 @@ bool Item_sum::init_sum_func_check(THD *thd)
     return TRUE;
   }
   /* Set a reference to the nesting set function if there is  any */
-  in_sum_func= lex_s->in_sum_func;
+  in_sum_func= thd->lex->in_sum_func;
   /* Save a pointer to object to be used in items for nested set functions */
-  lex_s->in_sum_func= this;
+  thd->lex->in_sum_func= this;
   nest_level= thd->lex->current_select->nest_level;
   ref_by= 0;
   aggr_level= -1;
@@ -152,7 +151,6 @@ bool Item_sum::init_sum_func_check(THD *thd)
 bool Item_sum::check_sum_func(THD *thd, Item **ref)
 {
   SELECT_LEX *curr_sel= thd->lex->current_select;
-  LEX *lex_s= curr_sel->parent_lex;
   nesting_map allow_sum_func= (thd->lex->allow_sum_func &
                                curr_sel->name_visibility_map);
   bool invalid= FALSE;
@@ -312,7 +310,7 @@ bool Item_sum::check_sum_func(THD *thd, Item **ref)
   }
   aggr_sel->set_agg_func_used(true);
   update_used_tables();
-  lex_s->in_sum_func= in_sum_func;
+  thd->lex->in_sum_func= in_sum_func;
   return FALSE;
 }
 
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 5173df260d5..9a66b27a454 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -6440,7 +6440,6 @@ set_new_item_local_context(THD *thd, Item_ident *item, TABLE_LIST *table_ref)
   if (!(context= new (thd->mem_root) Name_resolution_context))
     return TRUE;
   context->init();
-  context->select_lex= table_ref->select_lex;
   context->first_name_resolution_table=
     context->last_name_resolution_table= table_ref;
   item->context= context;
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index bb1a99d9eef..64e4cd30561 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -3060,7 +3060,6 @@ void reinit_stmt_before_use(THD *thd, LEX *lex)
   }
   for (; sl; sl= sl->next_select_in_list())
   {
-    sl->parent_lex->in_sum_func= NULL;
     if (sl->changed_elements & TOUCHED_SEL_COND)
     {
       /* remove option which was put by mysql_explain_union() */
@@ -3191,6 +3190,7 @@ void reinit_stmt_before_use(THD *thd, LEX *lex)
     lex->result->set_thd(thd);
   }
   lex->allow_sum_func= 0;
+  lex->in_sum_func= NULL;
   DBUG_VOID_RETURN;
 }