Partial backporting of 7b50447aa6d051b8d14bb01ef14802cb8ffee223

(MDEV-9407, MDEV-9408) from 10.1

Needed to fix MDEV-10317 easier.

11 files changed, 87 insertions, 127 deletions

diff --git a/sql/item.h b/sql/item.h
index 8650eb9382c..1905e0f1216 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -657,6 +657,8 @@ protected:
 
   SEL_TREE *get_mm_tree_for_const(RANGE_OPT_PARAM *param);
 
+  Field *create_tmp_field(bool group, TABLE *table, uint convert_int_length);
+
 public:
   /*
     Cache val_str() into the own buffer, e.g. to evaluate constant
@@ -1021,8 +1023,6 @@ public:
   int save_str_value_in_field(Field *field, String *result);
 
   virtual Field *get_tmp_table_field() { return 0; }
-  /* This is also used to create fields in CREATE ... SELECT: */
-  virtual Field *tmp_table_field(TABLE *t_arg) { return 0; }
   virtual Field *create_field_for_create_select(TABLE *table);
   virtual Field *create_field_for_schema(THD *thd, TABLE *table);
   virtual const char *full_name() const { return name ? name : "???"; }
@@ -1630,6 +1630,15 @@ public:
   // used in row subselects to get value of elements
   virtual void bring_value() {}
 
+  virtual Field *create_tmp_field(bool group, TABLE *table)
+  {
+    /*
+      Values with MY_INT32_NUM_DECIMAL_DIGITS digits may or may not fit into
+      Field_long : make them Field_longlong.
+    */
+    return create_tmp_field(false, table, MY_INT32_NUM_DECIMAL_DIGITS - 2);
+  }
+
   Field *tmp_table_field_from_field_type(TABLE *table,
                                          bool fixed_length,
                                          bool set_blob_packlength);
@@ -2224,7 +2233,6 @@ public:
   {}
   ~Item_result_field() {}			/* Required with gcc 2.95 */
   Field *get_tmp_table_field() { return result_field; }
-  Field *tmp_table_field(TABLE *t_arg) { return result_field; }
   /*
     This implementation of used_tables() used by Item_avg_field and
     Item_variance_field which work when only temporary table left, so theu
@@ -3397,8 +3405,6 @@ public:
   { return val_real_from_date(); }
   my_decimal *val_decimal(my_decimal *decimal_value)
   { return  val_decimal_from_date(decimal_value); }
-  Field *tmp_table_field(TABLE *table)
-  { return tmp_table_field_from_field_type(table, false, false); }
   int save_in_field(Field *field, bool no_conversions)
   { return save_date_in_field(field); }
 };
@@ -3903,7 +3909,6 @@ public:
   enum_field_types field_type() const   { return (*ref)->field_type(); }
   Field *get_tmp_table_field()
   { return result_field ? result_field : (*ref)->get_tmp_table_field(); }
-  Field *tmp_table_field(TABLE *t_arg) { return 0; } 
   Item *get_tmp_table_item(THD *thd);
   table_map used_tables() const;		
   void update_used_tables(); 
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index f3196c55873..bd1e8b72157 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -2263,11 +2263,6 @@ uint Item_func_case_abbreviation2::decimal_precision2(Item **args) const
 }
 
 
-Field *Item_func_ifnull::tmp_table_field(TABLE *table)
-{
-  return tmp_table_field_from_field_type(table, false, false);
-}
-
 double
 Item_func_ifnull::real_op()
 {
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 2f66382941d..2e066b895e9 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -951,7 +951,9 @@ public:
     maybe_null= args[1]->maybe_null;
   }
   const char *func_name() const { return "ifnull"; }
-  Field *tmp_table_field(TABLE *table);
+  Field *create_field_for_create_select(TABLE *table)
+  { return tmp_table_field_from_field_type(table, false, false); }
+
   table_map not_null_tables() const { return 0; }
   uint decimal_precision() const
   {
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 6edb276ca20..0d21183cac8 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -509,43 +509,6 @@ bool Item_func::eq(const Item *item, bool binary_cmp) const
 }
 
 
-Field *Item_func::tmp_table_field(TABLE *table)
-{
-  Field *field= NULL;
-  MEM_ROOT *mem_root= table->in_use->mem_root;
-
-  switch (result_type()) {
-  case INT_RESULT:
-    if (max_char_length() > MY_INT32_NUM_DECIMAL_DIGITS)
-      field= new (mem_root)
-        Field_longlong(max_char_length(), maybe_null, name,
-                       unsigned_flag);
-    else
-      field= new (mem_root)
-        Field_long(max_char_length(), maybe_null, name,
-                   unsigned_flag);
-    break;
-  case REAL_RESULT:
-    field= new (mem_root)
-      Field_double(max_char_length(), maybe_null, name, decimals);
-    break;
-  case STRING_RESULT:
-    return make_string_field(table);
-  case DECIMAL_RESULT:
-    field= Field_new_decimal::create_from_item(mem_root, this);
-    break;
-  case ROW_RESULT:
-  case TIME_RESULT:
-    // This case should never be chosen
-    DBUG_ASSERT(0);
-    field= 0;
-    break;
-  }
-  if (field)
-    field->init(table);
-  return field;
-}
-
 /*
 bool Item_func::is_expensive_processor(uchar *arg)
 {
@@ -2910,10 +2873,10 @@ void Item_func_min_max::fix_length_and_dec()
     collation.set_numeric();
     fix_char_length(float_length(decimals));
     /*
-      Set type to DOUBLE, as Item_func::tmp_table_field() does not
+      Set type to DOUBLE, as Item_func::create_tmp_field() does not
       distinguish between DOUBLE and FLOAT and always creates Field_double.
       Perhaps we should eventually change this to use agg_field_type() here,
-      and fix Item_func::tmp_table_field() to create Field_float when possible.
+      and fix Item_func::create_tmp_field() to create Field_float when possible.
     */
     set_handler_by_field_type(MYSQL_TYPE_DOUBLE);
     break;
@@ -6805,16 +6768,6 @@ longlong Item_func_found_rows::val_int()
 }
 
 
-Field *
-Item_func_sp::tmp_table_field(TABLE *t_arg)
-{
-  DBUG_ENTER("Item_func_sp::tmp_table_field");
-
-  DBUG_ASSERT(sp_result_field);
-  DBUG_RETURN(sp_result_field);
-}
-
-
 /**
   @brief Checks if requested access to function can be granted to user.
     If function isn't found yet, it searches function first.
diff --git a/sql/item_func.h b/sql/item_func.h
index a6d0374d491..47af2a3f898 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -173,12 +173,10 @@ public:
   }
   void signal_divide_by_null();
   friend class udf_handler;
-  Field *tmp_table_field() { return result_field; }
-  Field *tmp_table_field(TABLE *t_arg);
   Field *create_field_for_create_select(TABLE *table)
   {
     return result_type() != STRING_RESULT ?
-           tmp_table_field(table) :
+           create_tmp_field(false, table, MY_INT32_NUM_DECIMAL_DIGITS) :
            tmp_table_field_from_field_type(table, false, false);
   }
   Item *get_tmp_table_item(THD *thd);
@@ -1765,7 +1763,7 @@ public:
   Field *create_field_for_create_select(TABLE *table)
   {
     return result_type() != STRING_RESULT ?
-           tmp_table_field(table) :
+           create_tmp_field(false, table, MY_INT32_NUM_DECIMAL_DIGITS) :
            tmp_table_field_from_field_type(table, false, true);
   }
   table_map used_tables() const
@@ -2106,8 +2104,12 @@ public:
 
   enum enum_field_types field_type() const;
 
-  Field *tmp_table_field(TABLE *t_arg);
-
+  Field *create_field_for_create_select(TABLE *table)
+  {
+    return result_type() != STRING_RESULT ?
+           sp_result_field :
+           tmp_table_field_from_field_type(table, false, false);
+  }
   void make_field(Send_field *tmp_field);
 
   Item_result result_type() const;
diff --git a/sql/item_geofunc.cc b/sql/item_geofunc.cc
index 76e4a85e865..c856aa985b3 100644
--- a/sql/item_geofunc.cc
+++ b/sql/item_geofunc.cc
@@ -40,7 +40,7 @@
 #include "opt_range.h"
 
 
-Field *Item_geometry_func::tmp_table_field(TABLE *t_arg)
+Field *Item_geometry_func::create_field_for_create_select(TABLE *t_arg)
 {
   Field *result;
   if ((result= new Field_geom(max_length, maybe_null, name, t_arg->s,
diff --git a/sql/item_geofunc.h b/sql/item_geofunc.h
index 6b991a1b643..121e122d939 100644
--- a/sql/item_geofunc.h
+++ b/sql/item_geofunc.h
@@ -40,7 +40,7 @@ public:
   Item_geometry_func(THD *thd, List<Item> &list): Item_str_func(thd, list) {}
   void fix_length_and_dec();
   enum_field_types field_type() const  { return MYSQL_TYPE_GEOMETRY; }
-  Field *tmp_table_field(TABLE *t_arg);
+  Field *create_field_for_create_select(TABLE *table);
 };
 
 class Item_func_geometry_from_text: public Item_geometry_func
diff --git a/sql/item_sum.h b/sql/item_sum.h
index 11d2f802af7..8568eaae907 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -481,7 +481,7 @@ public:
   }
   virtual void make_unique() { force_copy_fields= TRUE; }
   Item *get_tmp_table_item(THD *thd);
-  virtual Field *create_tmp_field(bool group, TABLE *table);
+  Field *create_tmp_field(bool group, TABLE *table);
   virtual bool collect_outer_ref_processor(uchar *param);
   bool init_sum_func_check(THD *thd);
   bool check_sum_func(THD *thd, Item **ref);
@@ -1084,7 +1084,6 @@ public:
     fixed= true;
   }
   table_map used_tables() const { return (table_map) 1L; }
-  Field *tmp_table_field(TABLE *) { DBUG_ASSERT(0); return NULL; }
   void set_result_field(Field *) { DBUG_ASSERT(0); }
   void save_in_result_field(bool no_conversions) { DBUG_ASSERT(0); }
 };
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index bb840987089..2c1a0943699 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -500,7 +500,7 @@ public:
   bool get_date(MYSQL_TIME *res, ulonglong fuzzy_date) { DBUG_ASSERT(0); return 1; }
   my_decimal *val_decimal(my_decimal *decimal_value)
   { return  val_decimal_from_date(decimal_value); }
-  Field *tmp_table_field(TABLE *table)
+  Field *create_field_for_create_select(TABLE *table)
   { return tmp_table_field_from_field_type(table, false, false); }
   int save_in_field(Field *field, bool no_conversions)
   { return save_date_in_field(field); }
diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index 3efdd2535c2..b97bae6b23c 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -3927,8 +3927,8 @@ void select_insert::abort_result_set() {
 Field *Item::create_field_for_create_select(TABLE *table)
 {
   Field *def_field, *tmp_field;
-  return create_tmp_field(table->in_use, table, this, type(),
-                          (Item ***) 0, &tmp_field, &def_field, 0, 0, 0, 0);
+  return ::create_tmp_field(table->in_use, table, this, type(),
+                            (Item ***) 0, &tmp_field, &def_field, 0, 0, 0, 0);
 }
 
 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 86a7309315a..387e0403f96 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -15837,6 +15837,60 @@ Field *create_tmp_field_from_field(THD *thd, Field *org_field,
   return new_field;
 }
 
+
+Field *Item::create_tmp_field(bool group, TABLE *table, uint convert_int_length)
+{
+  Field *UNINIT_VAR(new_field);
+  MEM_ROOT *mem_root= table->in_use->mem_root;
+
+  switch (cmp_type()) {
+  case REAL_RESULT:
+    new_field= new (mem_root)
+      Field_double(max_length, maybe_null, name, decimals, TRUE);
+    break;
+  case INT_RESULT:
+    /*
+      Select an integer type with the minimal fit precision.
+      convert_int_length is sign inclusive, don't consider the sign.
+    */
+    if (max_char_length() > convert_int_length)
+      new_field= new (mem_root)
+        Field_longlong(max_char_length(), maybe_null, name, unsigned_flag);
+    else
+      new_field= new (mem_root)
+        Field_long(max_char_length(), maybe_null, name, unsigned_flag);
+    break;
+  case TIME_RESULT:
+    new_field= tmp_table_field_from_field_type(table, true, false);
+    break;
+  case STRING_RESULT:
+    DBUG_ASSERT(collation.collation);
+    /*
+      GEOMETRY fields have STRING_RESULT result type.
+      To preserve type they needed to be handled separately.
+    */
+    if (field_type() == MYSQL_TYPE_GEOMETRY)
+      new_field= tmp_table_field_from_field_type(table, true, false);
+    else
+      new_field= make_string_field(table);
+    new_field->set_derivation(collation.derivation, collation.repertoire);
+    break;
+  case DECIMAL_RESULT:
+    new_field= Field_new_decimal::create_from_item(mem_root, this);
+    break;
+  case ROW_RESULT:
+    // This case should never be choosen
+    DBUG_ASSERT(0);
+    new_field= 0;
+    break;
+  }
+  if (new_field)
+    new_field->init(table);
+  return new_field;
+}
+
+
+
 /**
   Create field for temporary table using type of given item.
 
@@ -15862,58 +15916,9 @@ Field *create_tmp_field_from_field(THD *thd, Field *org_field,
 static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table,
                                          Item ***copy_func, bool modify_item)
 {
-  bool maybe_null= item->maybe_null;
   Field *UNINIT_VAR(new_field);
-  MEM_ROOT *mem_root= thd->mem_root;
-
-  /*
-    To preserve type or DATE/TIME and GEOMETRY fields,
-    they need to be handled separately.
-  */
-  if (item->cmp_type() == TIME_RESULT ||
-      item->field_type() == MYSQL_TYPE_GEOMETRY)
-    new_field= item->tmp_table_field_from_field_type(table, true, false);
-  else
-  switch (item->result_type()) {
-  case REAL_RESULT:
-    new_field= new (mem_root)
-      Field_double(item->max_length, maybe_null,
-                   item->name, item->decimals, TRUE);
-    break;
-  case INT_RESULT:
-    /* 
-      Select an integer type with the minimal fit precision.
-      MY_INT32_NUM_DECIMAL_DIGITS is sign inclusive, don't consider the sign.
-      Values with MY_INT32_NUM_DECIMAL_DIGITS digits may or may not fit into 
-      Field_long : make them Field_longlong.  
-    */
-    if (item->max_length >= (MY_INT32_NUM_DECIMAL_DIGITS - 1))
-      new_field=new (mem_root)
-        Field_longlong(item->max_length, maybe_null,
-                       item->name, item->unsigned_flag);
-    else
-      new_field=new (mem_root)
-        Field_long(item->max_length, maybe_null, item->name,
-                   item->unsigned_flag);
-    break;
-  case STRING_RESULT:
-    DBUG_ASSERT(item->collation.collation);
-    new_field= item->make_string_field(table);
-    new_field->set_derivation(item->collation.derivation,
-                              item->collation.repertoire);
-    break;
-  case DECIMAL_RESULT:
-    new_field= Field_new_decimal::create_from_item(mem_root, item);
-    break;
-  case ROW_RESULT:
-  default:
-    // This case should never be choosen
-    DBUG_ASSERT(0);
-    new_field= 0;
-    break;
-  }
-  if (new_field)
-    new_field->init(table);
+  DBUG_ASSERT(thd == table->in_use);
+  new_field= item->Item::create_tmp_field(false, table);
     
   if (copy_func && item->real_item()->is_result_field())
     *((*copy_func)++) = item;			// Save for copy_funcs
@@ -16005,8 +16010,7 @@ Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
   switch (type) {
   case Item::SUM_FUNC_ITEM:
   {
-    Item_sum *item_sum=(Item_sum*) item;
-    result= item_sum->create_tmp_field(group, table);
+    result= item->create_tmp_field(group, table);
     if (!result)
       my_error(ER_OUT_OF_RESOURCES, MYF(ME_FATALERROR));
     return result;