MDEV-35840 Eliminate -warray-bounds triggered by TABLE_SHARE::db_type()

The warnings are triggered with -O3

sql/sql_base.cc

@@ -8953,8 +8953,9 @@ my_bool mysql_rm_tmp_tables(void)
           memcpy(path_copy, path, path_len - ext_len);
           path_copy[path_len - ext_len]= 0;
           init_tmp_table_share(thd, &share, "", 0, "", path_copy);
+          handlerton *ht= share.db_type();
           if (!open_table_def(thd, &share))
-            share.db_type()->drop_table(share.db_type(), path_copy);
+            ht->drop_table(share.db_type(), path_copy);
           free_table_share(&share);
         }
         /*

sql/sql_partition.cc

@@ -721,9 +721,11 @@ static bool handle_list_of_fields(THD *thd, List_iterator<const char> it,
     }
     else
     {
-      if (table->s->db_type()->partition_flags &&
-          (table->s->db_type()->partition_flags() & HA_USE_AUTO_PARTITION) &&
-          (table->s->db_type()->partition_flags() & HA_CAN_PARTITION))
+      handlerton *ht= table->s->db_type();
+      if (ht->partition_flags &&
+          ((ht->partition_flags() &
+            (HA_USE_AUTO_PARTITION | HA_CAN_PARTITION)) ==
+           (HA_USE_AUTO_PARTITION | HA_CAN_PARTITION)))
       {
         /*
           This engine can handle automatic partitioning and there is no
@@ -1927,6 +1929,7 @@ bool fix_partition_func(THD *thd, TABLE *table, bool is_create_table_ind)
   bool result= TRUE;
   partition_info *part_info= table->part_info;
   enum_column_usage saved_column_usage= thd->column_usage;
+  handlerton *ht;
   DBUG_ENTER("fix_partition_func");
 
   if (part_info->fixed)
@@ -2056,8 +2059,9 @@ bool fix_partition_func(THD *thd, TABLE *table, bool is_create_table_ind)
     goto end;
   if (unlikely(check_primary_key(table)))
     goto end;
-  if (unlikely((!(table->s->db_type()->partition_flags &&
-      (table->s->db_type()->partition_flags() & HA_CAN_PARTITION_UNIQUE))) &&
+  ht= table->s->db_type();
+  if (unlikely((!(ht->partition_flags &&
+      (ht->partition_flags() & HA_CAN_PARTITION_UNIQUE))) &&
                check_unique_keys(table)))
     goto end;
   if (unlikely(set_up_partition_bitmaps(thd, part_info)))
@@ -2713,12 +2717,14 @@ bool partition_key_modified(TABLE *table, const MY_BITMAP *fields)
 {
   Field **fld;
   partition_info *part_info= table->part_info;
+  handlerton *ht;
   DBUG_ENTER("partition_key_modified");
 
   if (!part_info)
     DBUG_RETURN(FALSE);
-  if (table->s->db_type()->partition_flags &&
-      (table->s->db_type()->partition_flags() & HA_CAN_UPDATE_PARTITION_KEY))
+  ht= table->s->db_type();
+  if (ht->partition_flags &&
+      (ht->partition_flags() & HA_CAN_UPDATE_PARTITION_KEY))
     DBUG_RETURN(FALSE);
   for (fld= part_info->full_part_field_array; *fld; fld++)
     if (bitmap_is_set(fields, (*fld)->field_index))
@@ -4927,11 +4933,10 @@ uint prep_alter_part_table(THD *thd, TABLE *table, Alter_info *alter_info,
          if default partitioning is used.
       */
 
+      handlerton *ht= table->s->db_type();
       if (tab_part_info->part_type != HASH_PARTITION ||
-          ((table->s->db_type()->partition_flags() & HA_USE_AUTO_PARTITION) &&
-           !tab_part_info->use_default_num_partitions) ||
-          ((!(table->s->db_type()->partition_flags() & HA_USE_AUTO_PARTITION)) &&
-           tab_part_info->use_default_num_partitions))
+          !(ht->partition_flags() & HA_USE_AUTO_PARTITION) ==
+          tab_part_info->use_default_num_partitions)
       {
         my_error(ER_REORG_NO_PARAM_ERROR, MYF(0));
         goto err;