MDEV-14026 ALTER TABLE ... DELAY_KEY_WRITE=1 creates table copy for partitioned MyISAM table with DATA DIRECTORY/INDEX DIRECTORY options

set data_file_name and index_file_name in HA_CREATE_INFO
before calling check_if_incompatible_data()

1 files changed, 25 insertions, 9 deletions

diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index 459af18f737..34c253cc48a 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -8133,20 +8133,36 @@ uint ha_partition::alter_table_flags(uint flags)
 bool ha_partition::check_if_incompatible_data(HA_CREATE_INFO *create_info,
                                               uint table_changes)
 {
-  handler **file;
-  bool ret= COMPATIBLE_DATA_YES;
-
   /*
     The check for any partitioning related changes have already been done
     in mysql_alter_table (by fix_partition_func), so it is only up to
     the underlying handlers.
   */
-  for (file= m_file; *file; file++)
-    if ((ret=  (*file)->check_if_incompatible_data(create_info,
-                                                   table_changes)) !=
-        COMPATIBLE_DATA_YES)
-      break;
-  return ret;
+  List_iterator<partition_element> part_it(m_part_info->partitions);
+  HA_CREATE_INFO dummy_info= *create_info;
+  uint i=0;
+  while (partition_element *part_elem= part_it++)
+  {
+    if (m_is_sub_partitioned)
+    {
+      List_iterator<partition_element> subpart_it(part_elem->subpartitions);
+      while (partition_element *sub_elem= subpart_it++)
+      {
+        dummy_info.data_file_name= sub_elem->data_file_name;
+        dummy_info.index_file_name= sub_elem->index_file_name;
+        if (m_file[i++]->check_if_incompatible_data(&dummy_info, table_changes))
+          return COMPATIBLE_DATA_NO;
+      }
+    }
+    else
+    {
+      dummy_info.data_file_name= part_elem->data_file_name;
+      dummy_info.index_file_name= part_elem->index_file_name;
+      if (m_file[i++]->check_if_incompatible_data(&dummy_info, table_changes))
+        return COMPATIBLE_DATA_NO;
+    }
+  }
+  return COMPATIBLE_DATA_YES;
 }