Remove calls to current_thd() in Item functions

- Added THD argument to functions that calls current_thd() or
  new without a mem_root argument:
  make_same(), set_comparator_func(), set_cmp_func(), set_cmp_func*(),
  set_aggregator() and prepare_sum_aggregators()
- Changed "new Class" to "new (thd->mem_root) Class"

Almost all changes mechanical, no logic changes.

12 files changed, 184 insertions, 164 deletions

diff --git a/plugin/type_inet/sql_type_inet.cc b/plugin/type_inet/sql_type_inet.cc
index ab251d660b3..58aa9ed6bde 100644
--- a/plugin/type_inet/sql_type_inet.cc
+++ b/plugin/type_inet/sql_type_inet.cc
@@ -601,9 +601,9 @@ public:
     DBUG_ASSERT(!tmp->m_null_value);
     return m_native.cmp(tmp->m_native);
   }
-  cmp_item *make_same() override
+  cmp_item *make_same(THD *thd) override
   {
-    return new cmp_item_inet6();
+    return new (thd->mem_root) cmp_item_inet6();
   }
 };
 
diff --git a/plugin/type_inet/sql_type_inet.h b/plugin/type_inet/sql_type_inet.h
index 0f110314620..a00b2d35f18 100644
--- a/plugin/type_inet/sql_type_inet.h
+++ b/plugin/type_inet/sql_type_inet.h
@@ -697,9 +697,9 @@ public:
     DBUG_ASSERT(b.length() == Inet6::binary_length());
     return memcmp(a.ptr(), b.ptr(), Inet6::binary_length());
   }
-  bool set_comparator_func(Arg_comparator *cmp) const override
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override
   {
-    return cmp->set_cmp_func_native();
+    return cmp->set_cmp_func_native(thd);
   }
   bool Item_const_eq(const Item_const *a, const Item_const *b,
                              bool binary_cmp) const override
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 97252b419e4..972ebb44054 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -355,8 +355,9 @@ static bool convert_const_to_int(THD *thd, Item_field *field_item,
 
       if (0 == field_cmp)
       {
-        Item *tmp= new (thd->mem_root) Item_int_with_ref(thd, field->val_int(), *item,
-                                         MY_TEST(field->flags & UNSIGNED_FLAG));
+        Item *tmp= (new (thd->mem_root)
+                    Item_int_with_ref(thd, field->val_int(), *item,
+                                      MY_TEST(field->flags & UNSIGNED_FLAG)));
         if (tmp)
           thd->change_item_tree(item, tmp);
         result= 1;					// Item was replaced
@@ -418,7 +419,7 @@ bool Item_func::setup_args_and_comparator(THD *thd, Arg_comparator *cmp)
   DBUG_ASSERT(functype() != LIKE_FUNC);
   convert_const_compared_to_int_field(thd);
 
-  return cmp->set_cmp_func(this, &args[0], &args[1], true);
+  return cmp->set_cmp_func(thd, this, &args[0], &args[1], true);
 }
 
 
@@ -466,7 +467,7 @@ bool Item_bool_rowready_func2::fix_length_and_dec()
   items, holding the cached converted value of the original (constant) item.
 */
 
-int Arg_comparator::set_cmp_func(Item_func_or_sum *owner_arg,
+int Arg_comparator::set_cmp_func(THD *thd, Item_func_or_sum *owner_arg,
                                  Item **a1, Item **a2)
 {
   owner= owner_arg;
@@ -477,15 +478,15 @@ int Arg_comparator::set_cmp_func(Item_func_or_sum *owner_arg,
   Type_handler_hybrid_field_type tmp;
   if (tmp.aggregate_for_comparison(owner_arg->func_name(), tmp_args, 2, false))
   {
-    DBUG_ASSERT(current_thd->is_error());
+    DBUG_ASSERT(thd->is_error());
     return 1;
   }
   m_compare_handler= tmp.type_handler();
-  return m_compare_handler->set_comparator_func(this);
+  return m_compare_handler->set_comparator_func(thd, this);
 }
 
 
-bool Arg_comparator::set_cmp_func_for_row_arguments()
+bool Arg_comparator::set_cmp_func_for_row_arguments(THD *thd)
 {
   uint n= (*a)->cols();
   if (n != (*b)->cols())
@@ -494,7 +495,7 @@ bool Arg_comparator::set_cmp_func_for_row_arguments()
     comparators= 0;
     return true;
   }
-  if (!(comparators= new Arg_comparator[n]))
+  if (!(comparators= new (thd->mem_root) Arg_comparator[n]))
     return true;
   for (uint i=0; i < n; i++)
   {
@@ -503,25 +504,24 @@ bool Arg_comparator::set_cmp_func_for_row_arguments()
       my_error(ER_OPERAND_COLUMNS, MYF(0), (*a)->element_index(i)->cols());
       return true;
     }
-    if (comparators[i].set_cmp_func(owner, (*a)->addr(i),
-                                           (*b)->addr(i), set_null))
+    if (comparators[i].set_cmp_func(thd, owner, (*a)->addr(i),
+                                    (*b)->addr(i), set_null))
       return true;
   }
   return false;
 }
 
 
-bool Arg_comparator::set_cmp_func_row()
+bool Arg_comparator::set_cmp_func_row(THD *thd)
 {
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_row :
                                 &Arg_comparator::compare_row;
-  return set_cmp_func_for_row_arguments();
+  return set_cmp_func_for_row_arguments(thd);
 }
 
 
-bool Arg_comparator::set_cmp_func_string()
+bool Arg_comparator::set_cmp_func_string(THD *thd)
 {
-  THD *thd= current_thd;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_string :
                                 &Arg_comparator::compare_string;
   if (compare_type() == STRING_RESULT &&
@@ -557,9 +557,8 @@ bool Arg_comparator::set_cmp_func_string()
 }
 
 
-bool Arg_comparator::set_cmp_func_time()
+bool Arg_comparator::set_cmp_func_time(THD *thd)
 {
-  THD *thd= current_thd;
   m_compare_collation= &my_charset_numeric;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_time :
                                 &Arg_comparator::compare_time;
@@ -569,9 +568,8 @@ bool Arg_comparator::set_cmp_func_time()
 }
 
 
-bool Arg_comparator::set_cmp_func_datetime()
+bool Arg_comparator::set_cmp_func_datetime(THD *thd)
 {
-  THD *thd= current_thd;
   m_compare_collation= &my_charset_numeric;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_datetime :
                                 &Arg_comparator::compare_datetime;
@@ -581,9 +579,8 @@ bool Arg_comparator::set_cmp_func_datetime()
 }
 
 
-bool Arg_comparator::set_cmp_func_native()
+bool Arg_comparator::set_cmp_func_native(THD *thd)
 {
-  THD *thd= current_thd;
   m_compare_collation= &my_charset_numeric;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_native :
                                 &Arg_comparator::compare_native;
@@ -593,9 +590,8 @@ bool Arg_comparator::set_cmp_func_native()
 }
 
 
-bool Arg_comparator::set_cmp_func_int()
+bool Arg_comparator::set_cmp_func_int(THD *thd)
 {
-  THD *thd= current_thd;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_int :
                                 &Arg_comparator::compare_int_signed;
   if ((*a)->field_type() == MYSQL_TYPE_YEAR &&
@@ -624,7 +620,7 @@ bool Arg_comparator::set_cmp_func_int()
 }
 
 
-bool Arg_comparator::set_cmp_func_real()
+bool Arg_comparator::set_cmp_func_real(THD *thd)
 {
   if ((((*a)->result_type() == DECIMAL_RESULT && !(*a)->const_item() &&
         (*b)->result_type() == STRING_RESULT  &&  (*b)->const_item()) ||
@@ -639,10 +635,9 @@ bool Arg_comparator::set_cmp_func_real()
      Do comparison as decimal rather than float, in order not to lose precision.
     */
     m_compare_handler= &type_handler_newdecimal;
-    return set_cmp_func_decimal();
+    return set_cmp_func_decimal(thd);
   }
 
-  THD *thd= current_thd;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_real :
                                 &Arg_comparator::compare_real;
   if ((*a)->decimals < NOT_FIXED_DEC && (*b)->decimals < NOT_FIXED_DEC)
@@ -658,9 +653,8 @@ bool Arg_comparator::set_cmp_func_real()
   return false;
 }
 
-bool Arg_comparator::set_cmp_func_decimal()
+bool Arg_comparator::set_cmp_func_decimal(THD *thd)
 {
-  THD *thd= current_thd;
   func= is_owner_equal_func() ? &Arg_comparator::compare_e_decimal :
                                 &Arg_comparator::compare_decimal;
   a= cache_converted_constant(thd, a, &a_cache, compare_type_handler());
@@ -4019,24 +4013,24 @@ bool Predicant_to_list_comparator::make_unique_cmp_items(THD *thd,
 }
 
 
-cmp_item* cmp_item_sort_string::make_same()
+cmp_item* cmp_item_sort_string::make_same(THD *thd)
 {
-  return new cmp_item_sort_string_in_static(cmp_charset);
+  return new (thd->mem_root) cmp_item_sort_string_in_static(cmp_charset);
 }
 
-cmp_item* cmp_item_int::make_same()
+cmp_item* cmp_item_int::make_same(THD *thd)
 {
-  return new cmp_item_int();
+  return new (thd->mem_root) cmp_item_int();
 }
 
-cmp_item* cmp_item_real::make_same()
+cmp_item* cmp_item_real::make_same(THD *thd)
 {
-  return new cmp_item_real();
+  return new (thd->mem_root) cmp_item_real();
 }
 
-cmp_item* cmp_item_row::make_same()
+cmp_item* cmp_item_row::make_same(THD *thd)
 {
-  return new cmp_item_row();
+  return new (thd->mem_root) cmp_item_row();
 }
 
 
@@ -4100,7 +4094,7 @@ void cmp_item_row::store_value_by_template(THD *thd, cmp_item *t, Item *item)
     item->null_value= 0;
     for (uint i=0; i < n; i++)
     {
-      if (!(comparators[i]= tmpl->comparators[i]->make_same()))
+      if (!(comparators[i]= tmpl->comparators[i]->make_same(thd)))
 	break;					// new failed
       comparators[i]->store_value_by_template(thd, tmpl->comparators[i],
 					      item->element_index(i));
@@ -4184,9 +4178,9 @@ int cmp_item_decimal::compare(cmp_item *arg)
 }
 
 
-cmp_item* cmp_item_decimal::make_same()
+cmp_item* cmp_item_decimal::make_same(THD *thd)
 {
-  return new cmp_item_decimal();
+  return new (thd->mem_root) cmp_item_decimal();
 }
 
 
@@ -4227,15 +4221,15 @@ int cmp_item_temporal::compare(cmp_item *ci)
 }
 
 
-cmp_item *cmp_item_datetime::make_same()
+cmp_item *cmp_item_datetime::make_same(THD *thd)
 {
-  return new cmp_item_datetime();
+  return new (thd->mem_root) cmp_item_datetime();
 }
 
 
-cmp_item *cmp_item_time::make_same()
+cmp_item *cmp_item_time::make_same(THD *thd)
 {
-  return new cmp_item_time();
+  return new (thd->mem_root) cmp_item_time();
 }
 
 
@@ -4275,9 +4269,9 @@ int cmp_item_timestamp::compare(cmp_item *arg)
 }
 
 
-cmp_item* cmp_item_timestamp::make_same()
+cmp_item* cmp_item_timestamp::make_same(THD *thd)
 {
-  return new cmp_item_timestamp();
+  return new (thd->mem_root) cmp_item_timestamp();
 }
 
 
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 33838d9f92c..99f17077e3b 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -56,7 +56,8 @@ class Arg_comparator: public Sql_alloc
   Item *a_cache, *b_cache;         // Cached values of a and b items
                                    //   when one of arguments is NULL.
 
-  int set_cmp_func(Item_func_or_sum *owner_arg, Item **a1, Item **a2);
+  int set_cmp_func(THD *thd, Item_func_or_sum *owner_arg,
+                   Item **a1, Item **a2);
 
   int compare_not_null_values(longlong val1, longlong val2)
   {
@@ -83,21 +84,21 @@ public:
     a_cache(0), b_cache(0) {};
 
 public:
-  bool set_cmp_func_for_row_arguments();
-  bool set_cmp_func_row();
-  bool set_cmp_func_string();
-  bool set_cmp_func_time();
-  bool set_cmp_func_datetime();
-  bool set_cmp_func_native();
-  bool set_cmp_func_int();
-  bool set_cmp_func_real();
-  bool set_cmp_func_decimal();
+  bool set_cmp_func_for_row_arguments(THD *thd);
+  bool set_cmp_func_row(THD *thd);
+  bool set_cmp_func_string(THD *thd);
+  bool set_cmp_func_time(THD *thd);
+  bool set_cmp_func_datetime(THD *thd);
+  bool set_cmp_func_native(THD *thd);
+  bool set_cmp_func_int(THD *thd);
+  bool set_cmp_func_real(THD *thd);
+  bool set_cmp_func_decimal(THD *thd);
 
-  inline int set_cmp_func(Item_func_or_sum *owner_arg,
+  inline int set_cmp_func(THD *thd, Item_func_or_sum *owner_arg,
 			  Item **a1, Item **a2, bool set_null_arg)
   {
     set_null= set_null_arg;
-    return set_cmp_func(owner_arg, a1, a2);
+    return set_cmp_func(thd, owner_arg, a1, a2);
   }
   inline int compare() { return (this->*func)(); }
 
@@ -538,9 +539,9 @@ public:
     return this;
   }
   bool fix_length_and_dec();
-  int set_cmp_func()
+  int set_cmp_func(THD *thd)
   {
-    return cmp.set_cmp_func(this, tmp_arg, tmp_arg + 1, true);
+    return cmp.set_cmp_func(thd, this, tmp_arg, tmp_arg + 1, true);
   }
   CHARSET_INFO *compare_collation() const { return cmp.compare_collation(); }
   const Type_handler *compare_type_handler() const
@@ -1560,7 +1561,7 @@ public:
   virtual int cmp_not_null(const Value *value)= 0;
   // for optimized IN with row
   virtual int compare(cmp_item *item)= 0;
-  virtual cmp_item *make_same()= 0;
+  virtual cmp_item *make_same(THD *thd)= 0;
   virtual void store_value_by_template(THD *thd, cmp_item *tmpl, Item *item)
   {
     store_value(item);
@@ -1633,7 +1634,7 @@ public:
     cmp_item_string *l_cmp= (cmp_item_string *) ci;
     return sortcmp(value_res, l_cmp->value_res, cmp_charset);
   } 
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
   void set_charset(CHARSET_INFO *cs)
   {
     cmp_charset= cs;
@@ -1667,7 +1668,7 @@ public:
     cmp_item_int *l_cmp= (cmp_item_int *)ci;
     return (value < l_cmp->value) ? -1 : ((value == l_cmp->value) ? 0 : 1);
   }
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 /*
@@ -1696,7 +1697,7 @@ public:
   }
   int cmp_not_null(const Value *val);
   int cmp(Item *arg);
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 
@@ -1713,7 +1714,7 @@ public:
   }
   int cmp_not_null(const Value *val);
   int cmp(Item *arg);
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 
@@ -1726,7 +1727,7 @@ public:
   int cmp_not_null(const Value *val);
   int cmp(Item *arg);
   int compare(cmp_item *ci);
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 
@@ -1756,7 +1757,7 @@ public:
     cmp_item_real *l_cmp= (cmp_item_real *) ci;
     return (value < l_cmp->value)? -1 : ((value == l_cmp->value) ? 0 : 1);
   }
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 
@@ -1769,7 +1770,7 @@ public:
   int cmp(Item *arg);
   int cmp_not_null(const Value *val);
   int compare(cmp_item *c);
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
 };
 
 
@@ -1806,7 +1807,7 @@ public:
     cmp_item_string *l_cmp= (cmp_item_string *) ci;
     return sortcmp(value_res, l_cmp->value_res, cmp_charset);
   }
-  cmp_item *make_same()
+  cmp_item *make_same(THD *thd)
   {
     return new cmp_item_sort_string_in_static(cmp_charset);
   }
@@ -2515,7 +2516,7 @@ public:
     return TRUE;
   }
   int compare(cmp_item *arg);
-  cmp_item *make_same();
+  cmp_item *make_same(THD *thd);
   void store_value_by_template(THD *thd, cmp_item *tmpl, Item *);
   friend class Item_func_in;
   cmp_item *get_comparator(uint i) { return comparators[i]; }
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 58e9a5acd7b..d64f93e917c 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -118,6 +118,7 @@ void Item_subselect::init(st_select_lex *select_lex,
   else
   {
     SELECT_LEX *outer_select= unit->outer_select();
+    THD *thd= unit->thd;
     /*
       do not take into account expression inside aggregate functions because
       they can access original table fields
@@ -127,9 +128,11 @@ void Item_subselect::init(st_select_lex *select_lex,
                     outer_select->parsing_place);
     if (unit->is_unit_op() &&
         (unit->first_select()->next_select() || unit->fake_select_lex))
-      engine= new subselect_union_engine(unit, result, this);
+      engine= new (thd->mem_root)
+        subselect_union_engine(unit, result, this);
     else
-      engine= new subselect_single_select_engine(select_lex, result, this);
+      engine= new (thd->mem_root)
+        subselect_single_select_engine(select_lex, result, this);
   }
   DBUG_PRINT("info", ("engine: %p", engine));
   DBUG_VOID_RETURN;
@@ -3318,7 +3321,7 @@ bool Item_exists_subselect::exists2in_processor(void *opt_arg)
     }
     else
     {
-      List<Item> *and_list= new List<Item>;
+      List<Item> *and_list= new (thd->mem_root) List<Item>;
       if (!and_list)
       {
         res= TRUE;
@@ -3598,7 +3601,8 @@ bool Item_in_subselect::setup_mat_engine()
   select_engine= (subselect_single_select_engine*) engine;
 
   /* Create/initialize execution objects. */
-  if (!(mat_engine= new subselect_hash_sj_engine(thd, this, select_engine)))
+  if (!(mat_engine= new (thd->mem_root)
+        subselect_hash_sj_engine(thd, this, select_engine)))
     DBUG_RETURN(TRUE);
 
   if (mat_engine->prepare(thd) ||
@@ -3636,7 +3640,7 @@ bool Item_in_subselect::init_left_expr_cache()
   if (!outer_join || !outer_join->table_count || !outer_join->tables_list)
     return TRUE;
 
-  if (!(left_expr_cache= new List<Cached_item>))
+  if (!(left_expr_cache= new (thd->mem_root) List<Cached_item>))
     return TRUE;
 
   for (uint i= 0; i < left_expr->cols(); i++)
@@ -3867,8 +3871,9 @@ int subselect_single_select_engine::prepare(THD *thd)
   {
     select_lex->cleanup();
   }
-  join= new JOIN(thd, select_lex->item_list,
-		 select_lex->options | SELECT_NO_UNLOCK, result);
+  join= (new (thd->mem_root)
+         JOIN(thd, select_lex->item_list,
+              select_lex->options | SELECT_NO_UNLOCK, result));
   if (!join || !result)
     return 1; /* Fatal error is set already. */
   prepared= 1;
@@ -5280,7 +5285,7 @@ bool subselect_hash_sj_engine::make_semi_join_conds()
   tmp_table_ref->init_one_table(&empty_clex_str, &table_name, NULL, TL_READ);
   tmp_table_ref->table= tmp_table;
 
-  context= new Name_resolution_context;
+  context= new (thd->mem_root) Name_resolution_context;
   context->init();
   context->first_name_resolution_table=
     context->last_name_resolution_table= tmp_table_ref;
@@ -5348,8 +5353,9 @@ subselect_hash_sj_engine::make_unique_engine()
   tab->preread_init_done= FALSE;
   tab->ref.tmp_table_index_lookup_init(thd, tmp_key, it, FALSE);
 
-  DBUG_RETURN(new subselect_uniquesubquery_engine(thd, tab, item_in,
-                                                  semi_join_conds));
+  DBUG_RETURN(new (thd->mem_root)
+              subselect_uniquesubquery_engine(thd, tab, item_in,
+                                              semi_join_conds));
 }
 
 
@@ -5745,14 +5751,15 @@ int subselect_hash_sj_engine::exec()
     if (strategy == PARTIAL_MATCH_MERGE)
     {
       pm_engine=
-        new subselect_rowid_merge_engine((subselect_uniquesubquery_engine*)
-                                         lookup_engine, tmp_table,
-                                         count_pm_keys,
-                                         has_covering_null_row,
-                                         has_covering_null_columns,
-                                         count_columns_with_nulls,
-                                         item, result,
-                                         semi_join_conds->argument_list());
+        (new (thd->mem_root)
+         subselect_rowid_merge_engine((subselect_uniquesubquery_engine*)
+                                      lookup_engine, tmp_table,
+                                      count_pm_keys,
+                                      has_covering_null_row,
+                                      has_covering_null_columns,
+                                      count_columns_with_nulls,
+                                      item, result,
+                                      semi_join_conds->argument_list()));
       if (!pm_engine ||
           pm_engine->prepare(thd) ||
           ((subselect_rowid_merge_engine*) pm_engine)->
@@ -5772,13 +5779,14 @@ int subselect_hash_sj_engine::exec()
     if (strategy == PARTIAL_MATCH_SCAN)
     {
       if (!(pm_engine=
-            new subselect_table_scan_engine((subselect_uniquesubquery_engine*)
-                                            lookup_engine, tmp_table,
-                                            item, result,
-                                            semi_join_conds->argument_list(),
-                                            has_covering_null_row,
-                                            has_covering_null_columns,
-                                            count_columns_with_nulls)) ||
+            (new (thd->mem_root)
+             subselect_table_scan_engine((subselect_uniquesubquery_engine*)
+                                         lookup_engine, tmp_table,
+                                         item, result,
+                                         semi_join_conds->argument_list(),
+                                         has_covering_null_row,
+                                         has_covering_null_columns,
+                                         count_columns_with_nulls))) ||
           pm_engine->prepare(thd))
       {
         /* This is an irrecoverable error. */
@@ -6409,8 +6417,9 @@ subselect_rowid_merge_engine::init(MY_BITMAP *non_null_key_parts,
   /* Create the only non-NULL key if there is any. */
   if (non_null_key_parts)
   {
-    non_null_key= new Ordered_key(cur_keyid, tmp_table, left,
-                                  0, 0, 0, row_num_to_rowid);
+    non_null_key= (new (thd->mem_root)
+                   Ordered_key(cur_keyid, tmp_table, left,
+                               0, 0, 0, row_num_to_rowid));
     if (non_null_key->init(non_null_key_parts))
       return TRUE;
     merge_keys[cur_keyid]= non_null_key;
@@ -6439,13 +6448,13 @@ subselect_rowid_merge_engine::init(MY_BITMAP *non_null_key_parts,
           result_sink->get_null_count_of_col(i) == row_count)
         continue;
 
-      merge_keys[cur_keyid]= new Ordered_key(
-                                     cur_keyid, tmp_table,
-                                     left->element_index(i),
-                                     result_sink->get_null_count_of_col(i),
-                                     result_sink->get_min_null_of_col(i),
-                                     result_sink->get_max_null_of_col(i),
-                                     row_num_to_rowid);
+      merge_keys[cur_keyid]= new (thd->mem_root)
+          Ordered_key(cur_keyid, tmp_table,
+                      left->element_index(i),
+                      result_sink->get_null_count_of_col(i),
+                      result_sink->get_min_null_of_col(i),
+                      result_sink->get_max_null_of_col(i),
+                      row_num_to_rowid);
       if (merge_keys[cur_keyid]->init(i))
         return TRUE;
       merge_keys[cur_keyid]->first();
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 6acf7bb234b..e86327e22e5 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -478,7 +478,7 @@ Item_sum::Item_sum(THD *thd, Item_sum *item):
   init_aggregator();
   with_distinct= item->with_distinct;
   if (item->aggr)
-    set_aggregator(item->aggr->Aggrtype());
+    set_aggregator(thd, item->aggr->Aggrtype());
 }
 
 
@@ -579,7 +579,7 @@ Item *Item_sum::set_arg(uint i, THD *thd, Item *new_val)
 }
 
 
-int Item_sum::set_aggregator(Aggregator::Aggregator_type aggregator)
+int Item_sum::set_aggregator(THD *thd, Aggregator::Aggregator_type aggregator)
 {
   /*
     Dependent subselects may be executed multiple times, making
@@ -600,10 +600,10 @@ int Item_sum::set_aggregator(Aggregator::Aggregator_type aggregator)
   switch (aggregator)
   {
   case Aggregator::DISTINCT_AGGREGATOR:
-    aggr= new Aggregator_distinct(this);
+    aggr= new (thd->mem_root) Aggregator_distinct(this);
     break;
   case Aggregator::SIMPLE_AGGREGATOR:
-    aggr= new Aggregator_simple(this);
+    aggr= new (thd->mem_root) Aggregator_simple(this);
     break;
   };
   return aggr ? FALSE : TRUE;
@@ -763,7 +763,7 @@ bool Aggregator_distinct::setup(THD *thd)
     List<Item> list;
     SELECT_LEX *select_lex= thd->lex->current_select;
 
-    if (!(tmp_table_param= new TMP_TABLE_PARAM))
+    if (!(tmp_table_param= new (thd->mem_root) TMP_TABLE_PARAM))
       return TRUE;
 
     /* Create a table with an unique key over all parameters */
@@ -863,8 +863,9 @@ bool Aggregator_distinct::setup(THD *thd)
         }
       }
       DBUG_ASSERT(tree == 0);
-      tree= new Unique(compare_key, cmp_arg, tree_key_length,
-                       item_sum->ram_limitation(thd));
+      tree= (new (thd->mem_root)
+             Unique(compare_key, cmp_arg, tree_key_length,
+                    item_sum->ram_limitation(thd)));
       /*
         The only time tree_key_length could be 0 is if someone does
         count(distinct) on a char(0) field - stupid thing to do,
@@ -921,8 +922,9 @@ bool Aggregator_distinct::setup(THD *thd)
       simple_raw_key_cmp because the table contains numbers only; decimals
       are converted to binary representation as well.
     */
-    tree= new Unique(simple_raw_key_cmp, &tree_key_length, tree_key_length,
-                     item_sum->ram_limitation(thd));
+    tree= (new (thd->mem_root)
+           Unique(simple_raw_key_cmp, &tree_key_length, tree_key_length,
+                  item_sum->ram_limitation(thd)));
 
     DBUG_RETURN(tree == 0);
   }
@@ -1278,9 +1280,9 @@ void Item_sum_min_max::setup_hybrid(THD *thd, Item *item, Item *value_arg)
   /* Don't cache value, as it will change */
   if (!item->const_item())
     arg_cache->set_used_tables(RAND_TABLE_BIT);
-  cmp= new Arg_comparator();
+  cmp= new (thd->mem_root) Arg_comparator();
   if (cmp)
-    cmp->set_cmp_func(this, (Item**)&arg_cache, (Item**)&value, FALSE);
+    cmp->set_cmp_func(thd, this, (Item**)&arg_cache, (Item**)&value, FALSE);
   DBUG_VOID_RETURN;
 }
 
@@ -4292,7 +4294,7 @@ bool Item_func_group_concat::setup(THD *thd)
   if (table || tree)
     DBUG_RETURN(FALSE);
 
-  if (!(tmp_table_param= new TMP_TABLE_PARAM))
+  if (!(tmp_table_param= new (thd->mem_root) TMP_TABLE_PARAM))
     DBUG_RETURN(TRUE);
 
   /* Push all not constant fields to the list and create a temp table */
@@ -4381,7 +4383,7 @@ bool Item_func_group_concat::setup(THD *thd)
     with ORDER BY | DISTINCT and BLOB field count > 0.    
   */
   if (order_or_distinct && table->s->blob_fields)
-    table->blob_storage= new Blob_mem_storage();
+    table->blob_storage= new (thd->mem_root) Blob_mem_storage();
 
   /*
      Need sorting or uniqueness: init tree and choose a function to sort.
@@ -4407,10 +4409,11 @@ bool Item_func_group_concat::setup(THD *thd)
   }
 
   if (distinct)
-    unique_filter= new Unique(get_comparator_function_for_distinct(),
-                              (void*)this,
-                              tree_key_length + get_null_bytes(),
-                              ram_limitation(thd));
+    unique_filter= (new (thd->mem_root)
+                    Unique(get_comparator_function_for_distinct(),
+                           (void*)this,
+                           tree_key_length + get_null_bytes(),
+                           ram_limitation(thd)));
   if ((row_limit && row_limit->cmp_type() != INT_RESULT) ||
       (offset_limit && offset_limit->cmp_type() != INT_RESULT))
   {
diff --git a/sql/item_sum.h b/sql/item_sum.h
index 9c9ee34037d..02da520048b 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -512,7 +512,7 @@ public:
   */
   virtual void no_rows_in_result()
   {
-    set_aggregator(with_distinct ?
+    set_aggregator(current_thd, with_distinct ?
                    Aggregator::DISTINCT_AGGREGATOR :
                    Aggregator::SIMPLE_AGGREGATOR);
     aggregator_clear();
@@ -576,7 +576,7 @@ public:
     May be called multiple times.
   */
 
-  int set_aggregator(Aggregator::Aggregator_type aggregator);
+  int set_aggregator(THD *thd, Aggregator::Aggregator_type aggregator);
 
   virtual void clear()= 0;
   virtual bool add()= 0;
diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index edefbc83787..b3871254e6e 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -448,7 +448,8 @@ int opt_sum_query(THD *thd,
           const_result= 0;
           break;
         }
-        item_sum->set_aggregator(item_sum->has_with_distinct() ? 
+        item_sum->set_aggregator(thd,
+                                 item_sum->has_with_distinct() ?
                                  Aggregator::DISTINCT_AGGREGATOR :
                                  Aggregator::SIMPLE_AGGREGATOR);
         /*
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 48f18ecd64f..fa20e2a8d0d 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -277,7 +277,8 @@ static void update_tmptable_sum_func(Item_sum **func,TABLE *tmp_table);
 static void copy_sum_funcs(Item_sum **func_ptr, Item_sum **end);
 static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab);
 static bool setup_sum_funcs(THD *thd, Item_sum **func_ptr);
-static bool prepare_sum_aggregators(Item_sum **func_ptr, bool need_distinct);
+static bool prepare_sum_aggregators(THD *thd, Item_sum **func_ptr,
+                                    bool need_distinct);
 static bool init_sum_functions(Item_sum **func, Item_sum **end);
 static bool update_sum_func(Item_sum **func);
 static void select_describe(JOIN *join, bool need_tmp_table,bool need_order,
@@ -3605,7 +3606,7 @@ bool JOIN::make_aggr_tables_info()
       {
         if (make_sum_func_list(*curr_all_fields, *curr_fields_list, true, true))
           DBUG_RETURN(true);
-        if (prepare_sum_aggregators(sum_funcs,
+        if (prepare_sum_aggregators(thd, sum_funcs,
                                     !join_tab->is_using_agg_loose_index_scan()))
           DBUG_RETURN(true);
         group_list= NULL;
@@ -3715,7 +3716,7 @@ bool JOIN::make_aggr_tables_info()
     }
     if (make_sum_func_list(*curr_all_fields, *curr_fields_list, true, true))
       DBUG_RETURN(true);
-    if (prepare_sum_aggregators(sum_funcs,
+    if (prepare_sum_aggregators(thd, sum_funcs,
                                 !join_tab ||
                                 !join_tab-> is_using_agg_loose_index_scan()))
       DBUG_RETURN(true);
@@ -3920,7 +3921,7 @@ JOIN::create_postjoin_aggr_table(JOIN_TAB *tab, List<Item> *table_fields,
       goto err;
     if (make_sum_func_list(all_fields, fields_list, true))
       goto err;
-    if (prepare_sum_aggregators(sum_funcs,
+    if (prepare_sum_aggregators(thd, sum_funcs,
                                 !(tables_list && 
                                   join_tab->is_using_agg_loose_index_scan())))
       goto err;
@@ -3932,7 +3933,7 @@ JOIN::create_postjoin_aggr_table(JOIN_TAB *tab, List<Item> *table_fields,
   {
     if (make_sum_func_list(all_fields, fields_list, false))
       goto err;
-    if (prepare_sum_aggregators(sum_funcs,
+    if (prepare_sum_aggregators(thd, sum_funcs,
                                 !join_tab->is_using_agg_loose_index_scan()))
       goto err;
     if (setup_sum_funcs(thd, sum_funcs))
@@ -15134,7 +15135,7 @@ static bool check_row_equality(THD *thd, const Arg_comparator *comparators,
     {
       Item_func_eq *eq_item;
       if (!(eq_item= new (thd->mem_root) Item_func_eq(thd, left_item, right_item)) ||
-          eq_item->set_cmp_func())
+          eq_item->set_cmp_func(thd))
         return FALSE;
       eq_item->quick_fix_field();
       eq_list->push_back(eq_item, thd->mem_root);
@@ -15894,7 +15895,7 @@ Item *eliminate_item_equal(THD *thd, COND *cond, COND_EQUAL *upper_levels,
           Don't produce equality if const is equal to item_const.
         */
         Item_func_eq *func= new (thd->mem_root) Item_func_eq(thd, item_const, upper_const);
-        func->set_cmp_func();
+        func->set_cmp_func(thd);
         func->quick_fix_field();
         if (func->val_int())
           item= 0;
@@ -15942,7 +15943,7 @@ Item *eliminate_item_equal(THD *thd, COND *cond, COND_EQUAL *upper_levels,
                                                 field_item->remove_item_direct_ref(),
                                                 head_item->remove_item_direct_ref());
 
-      if (!eq_item || eq_item->set_cmp_func())
+      if (!eq_item || eq_item->set_cmp_func(thd))
         return 0;
       eq_item->quick_fix_field();
     }
@@ -16360,7 +16361,7 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
         So make sure to use set_cmp_func() only for non-LIKE operators.
       */
       if (functype != Item_func::LIKE_FUNC)
-        ((Item_bool_rowready_func2*) func)->set_cmp_func();
+        ((Item_bool_rowready_func2*) func)->set_cmp_func(thd);
     }
   }
   else if (can_change_cond_ref_to_const(func, left_item, right_item,
@@ -16385,7 +16386,7 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
 	  save_list->push_back(tmp2);
       }
       if (functype != Item_func::LIKE_FUNC)
-        ((Item_bool_rowready_func2*) func)->set_cmp_func();
+        ((Item_bool_rowready_func2*) func)->set_cmp_func(thd);
     }
   }
 }
@@ -25915,13 +25916,15 @@ static bool setup_sum_funcs(THD *thd, Item_sum **func_ptr)
 }
 
 
-static bool prepare_sum_aggregators(Item_sum **func_ptr, bool need_distinct)
+static bool prepare_sum_aggregators(THD *thd,Item_sum **func_ptr,
+                                    bool need_distinct)
 {
   Item_sum *func;
   DBUG_ENTER("prepare_sum_aggregators");
   while ((func= *(func_ptr++)))
   {
-    if (func->set_aggregator(need_distinct && func->has_with_distinct() ?
+    if (func->set_aggregator(thd,
+                             need_distinct && func->has_with_distinct() ?
                              Aggregator::DISTINCT_AGGREGATOR :
                              Aggregator::SIMPLE_AGGREGATOR))
       DBUG_RETURN(TRUE);
diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index b2128d1dfce..7c60bf09ae9 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -4347,46 +4347,54 @@ int Type_handler_int_result::Item_save_in_field(Item *item, Field *field,
 
 /***********************************************************************/
 
-bool Type_handler_row::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_row::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_row();
+  return cmp->set_cmp_func_row(thd);
 }
 
-bool Type_handler_int_result::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_int_result::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_int();
+  return cmp->set_cmp_func_int(thd);
 }
 
-bool Type_handler_real_result::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_real_result::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_real();
+  return cmp->set_cmp_func_real(thd);
 }
 
-bool Type_handler_decimal_result::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_decimal_result::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_decimal();
+  return cmp->set_cmp_func_decimal(thd);
 }
 
-bool Type_handler_string_result::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_string_result::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_string();
+  return cmp->set_cmp_func_string(thd);
 }
 
-bool Type_handler_time_common::set_comparator_func(Arg_comparator *cmp) const
+bool Type_handler_time_common::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_time();
+  return cmp->set_cmp_func_time(thd);
 }
 
 bool
-Type_handler_temporal_with_date::set_comparator_func(Arg_comparator *cmp) const
+Type_handler_temporal_with_date::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_datetime();
+  return cmp->set_cmp_func_datetime(thd);
 }
 
 bool
-Type_handler_timestamp_common::set_comparator_func(Arg_comparator *cmp) const
+Type_handler_timestamp_common::
+set_comparator_func(THD *thd, Arg_comparator *cmp) const
 {
-  return cmp->set_cmp_func_native();
+  return cmp->set_cmp_func_native(thd);
 }
 
 
diff --git a/sql/sql_type.h b/sql/sql_type.h
index 6cd462430f9..bf2c92b3f50 100644
--- a/sql/sql_type.h
+++ b/sql/sql_type.h
@@ -4181,7 +4181,7 @@ public:
     DBUG_ASSERT(0);
     return 0;
   }
-  virtual bool set_comparator_func(Arg_comparator *cmp) const= 0;
+  virtual bool set_comparator_func(THD *thd, Arg_comparator *cmp) const= 0;
   virtual bool Item_const_eq(const Item_const *a, const Item_const *b,
                              bool binary_cmp) const
   {
@@ -4521,7 +4521,7 @@ public:
     DBUG_ASSERT(0);
     return NULL;
   }
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
@@ -4818,7 +4818,7 @@ public:
                          const override;
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp)
                                        const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
@@ -4954,7 +4954,7 @@ public:
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp) const
     override;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
@@ -5188,7 +5188,7 @@ public:
   int Item_save_in_field(Item *item, Field *field, bool no_conversions) const override;
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp) const override;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
@@ -5452,7 +5452,7 @@ public:
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp) const
     override;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
@@ -6168,7 +6168,7 @@ public:
   bool Item_func_int_val_fix_length_and_dec(Item_func_int_val*) const override;
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp)
                                        const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   cmp_item *make_cmp_item(THD *thd, CHARSET_INFO *cs) const override;
   in_vector *make_in_vector(THD *, const Item_func_in *, uint nargs)
                             const override;
@@ -6262,7 +6262,7 @@ public:
                          const override;
   Item *make_const_item_for_comparison(THD *, Item *src, const Item *cmp)
                                        const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   cmp_item *make_cmp_item(THD *thd, CHARSET_INFO *cs) const override;
   in_vector *make_in_vector(THD *, const Item_func_in *, uint nargs)
                             const override;
@@ -6632,7 +6632,7 @@ public:
   longlong Item_func_min_max_val_int(Item_func_min_max *) const override;
   my_decimal *Item_func_min_max_val_decimal(Item_func_min_max *,
                                             my_decimal *) const override;
-  bool set_comparator_func(Arg_comparator *cmp) const override;
+  bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
diff --git a/sql/sql_window.cc b/sql/sql_window.cc
index 621a4b24227..ce0462f1bb0 100644
--- a/sql/sql_window.cc
+++ b/sql/sql_window.cc
@@ -2964,7 +2964,8 @@ bool Window_func_runner::exec(THD *thd, TABLE *tbl, SORT_INFO *filesort_result)
     win_func->set_phase_to_computation();
     // TODO(cvicentiu) Setting the aggregator should probably be done during
     // setup of Window_funcs_sort.
-    win_func->window_func()->set_aggregator(Aggregator::SIMPLE_AGGREGATOR);
+    win_func->window_func()->set_aggregator(thd,
+                                            Aggregator::SIMPLE_AGGREGATOR);
   }
   it.rewind();