MDEV-19345 Cleanup inconsistency in setting HA_(BLOB|VAR_LENGTH|BIT)_PART flags

sql/field.h

@@ -1025,6 +1025,8 @@ class Field: public Value_source
   virtual bool binary() const { return 1; }
   virtual bool zero_pack() const { return 1; }
   virtual enum ha_base_keytype key_type() const { return HA_KEYTYPE_BINARY; }
+  virtual uint16 key_part_flag() const { return 0; }
+  virtual uint16 key_part_length_bytes() const { return 0; }
   virtual uint32 key_length() const { return pack_length(); }
   virtual const Type_handler *type_handler() const= 0;
   virtual enum_field_types type() const
@@ -3653,6 +3655,8 @@ class Field_varstring :public Field_longstr {
 
   const Type_handler *type_handler() const { return &type_handler_varchar; }
   enum ha_base_keytype key_type() const;
+  uint16 key_part_flag() const { return HA_VAR_LENGTH_PART; }
+  uint16 key_part_length_bytes() const { return HA_KEY_BLOB_LENGTH; }
   uint row_pack_length() const { return field_length; }
   bool zero_pack() const { return 0; }
   int  reset(void) { bzero(ptr,field_length+length_bytes); return 0; }
@@ -3868,6 +3872,8 @@ class Field_blob :public Field_longstr {
   }
   enum ha_base_keytype key_type() const
     { return binary() ? HA_KEYTYPE_VARBINARY2 : HA_KEYTYPE_VARTEXT2; }
+  uint16 key_part_flag() const { return HA_BLOB_PART; }
+  uint16 key_part_length_bytes() const { return HA_KEY_BLOB_LENGTH; }
   Type_std_attributes type_std_attributes() const
   {
     return Type_std_attributes(Field_blob::max_display_length(), decimals(),
@@ -4354,6 +4360,7 @@ class Field_bit :public Field {
             enum utype unireg_check_arg, const LEX_CSTRING *field_name_arg);
   const Type_handler *type_handler() const { return &type_handler_bit; }
   enum ha_base_keytype key_type() const { return HA_KEYTYPE_BIT; }
+  uint16 key_part_flag() const { return HA_BIT_PART; }
   uint32 key_length() const { return (uint32) (field_length + 7) / 8; }
   uint32 max_data_length() const { return (field_length + 7) / 8; }
   uint32 max_display_length() const { return field_length; }

sql/sql_select.cc

@@ -18628,19 +18628,8 @@ bool Create_tmp_table::finalize(THD *thd,
         m_key_part_info->store_length+= HA_KEY_NULL_LENGTH;
         m_key_part_info->key_part_flag |= HA_NULL_PART;
       }
-      if ((*reg_field)->type() == MYSQL_TYPE_BLOB ||
-          (*reg_field)->real_type() == MYSQL_TYPE_VARCHAR ||
-          (*reg_field)->type() == MYSQL_TYPE_GEOMETRY)
-      {
-        if ((*reg_field)->type() == MYSQL_TYPE_BLOB ||
-            (*reg_field)->type() == MYSQL_TYPE_GEOMETRY)
-          m_key_part_info->key_part_flag|= HA_BLOB_PART;
-        else
-          m_key_part_info->key_part_flag|= HA_VAR_LENGTH_PART;
-
-        m_key_part_info->store_length+=HA_KEY_BLOB_LENGTH;
-      }
-
+      m_key_part_info->key_part_flag|= (*reg_field)->key_part_flag();
+      m_key_part_info->store_length+= (*reg_field)->key_part_length_bytes();
       keyinfo->key_length+= m_key_part_info->store_length;
 
       m_key_part_info->type=     (uint8) (*reg_field)->key_type();

sql/table.cc

@@ -2552,7 +2552,7 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
         KEY_PART_INFO *new_key_part= (keyinfo-1)->key_part +
                                      (keyinfo-1)->ext_key_parts;
         uint add_keyparts_for_this_key= add_first_key_parts;
-        uint length_bytes= 0, len_null_byte= 0, ext_key_length= 0;
+        uint len_null_byte= 0, ext_key_length= 0;
         Field *field;
 
         if ((keyinfo-1)->algorithm == HA_KEY_ALG_LONG_HASH)
@@ -2564,19 +2564,15 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
 	*/ 
         for (i= 0; i < keyinfo->user_defined_key_parts; i++)
         {
+          uint length_bytes= 0;
           uint fieldnr= keyinfo->key_part[i].fieldnr;
           field= share->field[fieldnr-1];
 
           if (field->null_ptr)
             len_null_byte= HA_KEY_NULL_LENGTH;
 
-          if ((field->type() == MYSQL_TYPE_BLOB ||
-             field->real_type() == MYSQL_TYPE_VARCHAR ||
-             field->type() == MYSQL_TYPE_GEOMETRY) &&
-             keyinfo->algorithm != HA_KEY_ALG_LONG_HASH )
-          {
-            length_bytes= HA_KEY_BLOB_LENGTH;
-          }
+          if (keyinfo->algorithm != HA_KEY_ALG_LONG_HASH)
+            length_bytes= field->key_part_length_bytes();
 
           ext_key_length+= keyinfo->key_part[i].length + len_null_byte
                             + length_bytes;
@@ -2665,20 +2661,11 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
           keyinfo->flags|=HA_NULL_PART_KEY;
           keyinfo->key_length+= HA_KEY_NULL_LENGTH;
         }
-        if (field->type() == MYSQL_TYPE_BLOB ||
-            field->real_type() == MYSQL_TYPE_VARCHAR ||
-            field->type() == MYSQL_TYPE_GEOMETRY)
-        {
-          if (field->type() == MYSQL_TYPE_BLOB ||
-              field->type() == MYSQL_TYPE_GEOMETRY)
-            key_part->key_part_flag|= HA_BLOB_PART;
-          else
-            key_part->key_part_flag|= HA_VAR_LENGTH_PART;
-          key_part->store_length+=HA_KEY_BLOB_LENGTH;
-          keyinfo->key_length+= HA_KEY_BLOB_LENGTH;
-        }
-        if (field->type() == MYSQL_TYPE_BIT)
-          key_part->key_part_flag|= HA_BIT_PART;
+
+        key_part->key_part_flag|= field->key_part_flag();
+        uint16 key_part_length_bytes= field->key_part_length_bytes();
+        key_part->store_length+= key_part_length_bytes;
+        keyinfo->key_length+= key_part_length_bytes;
 
         if (i == 0 && key != primary_key)
           field->flags |= (((keyinfo->flags & HA_NOSAME ||
@@ -7481,14 +7468,9 @@ void TABLE::create_key_part_by_field(KEY_PART_INFO *key_part_info,
   {
     key_part_info->store_length+= HA_KEY_NULL_LENGTH;
   }
-  if (field->type() == MYSQL_TYPE_BLOB || 
-      field->type() == MYSQL_TYPE_GEOMETRY ||
-      field->real_type() == MYSQL_TYPE_VARCHAR)
-  {
-    key_part_info->store_length+= HA_KEY_BLOB_LENGTH;
-    key_part_info->key_part_flag|=
-      field->type() == MYSQL_TYPE_BLOB ? HA_BLOB_PART: HA_VAR_LENGTH_PART;
-  }
+
+  key_part_info->key_part_flag|= field->key_part_flag();
+  key_part_info->store_length+= field->key_part_length_bytes();
 
   key_part_info->type=     (uint8) field->key_type();
   key_part_info->key_type =