MDEV-28576 RENAME COLUMN with NOCOPY algorithm leads to corrupt parti…

…tioned table

When f.ex. table is partitioned by HASH(a) and we rename column `a' to
`b' partitioning filter stays unchanged: HASH(a). That's the wrong
behavior.

The patch updates partitioning filter in accordance to the new columns
names. That includes partition/subpartition expression and
partition/subpartition field list.

mysql-test/main/partition_alter.result

@@ -200,4 +200,15 @@ pk
 2
 delete from t1;
 drop table t1;
+#
+# MDEV-28576 RENAME COLUMN with NOCOPY algorithm leads to corrupt partitioned table
+#
+create table t (a int, b int) partition by list (b) (partition p1 values in (1, 2));
+insert into t values (0, 1), (2, 2);
+alter table t change b f int, change a b int, algorithm=nocopy;
+check table t;
+Table	Op	Msg_type	Msg_text
+test.t	check	status	OK
+delete from t order by b limit 1;
+drop table t;
 # End of 10.3 tests

mysql-test/main/partition_alter.test

@@ -185,4 +185,15 @@ select * from t1 partition(p1);
 delete from t1;
 drop table t1;
 
+--echo #
+--echo # MDEV-28576 RENAME COLUMN with NOCOPY algorithm leads to corrupt partitioned table
+--echo #
+create table t (a int, b int) partition by list (b) (partition p1 values in (1, 2));
+insert into t values (0, 1), (2, 2);
+alter table t change b f int, change a b int, algorithm=nocopy;
+check table t;
+delete from t order by b limit 1;
+# cleanup
+drop table t;
+
 --echo # End of 10.3 tests

sql/sql_table.cc

@@ -7975,6 +7975,20 @@ void append_drop_column(THD *thd, String *str, Field *field)
 }
 
 
+static inline
+void rename_field_in_list(Create_field *field, List<const char> *field_list)
+{
+  DBUG_ASSERT(field->change.str);
+  List_iterator<const char> it(*field_list);
+  while (const char *name= it++)
+  {
+    if (my_strcasecmp(system_charset_info, name, field->change.str))
+      continue;
+    it.replace(field->field_name.str);
+  }
+}
+
+
 /**
   Prepare column and key definitions for CREATE TABLE in ALTER TABLE.
 
@@ -8284,6 +8298,39 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       new_create_tail.push_back(def, thd->mem_root);
     }
   }
+
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+  if (alter_info->flags & ALTER_RENAME_COLUMN)
+  {
+    if (thd->work_part_info)
+    {
+      partition_info *part_info= thd->work_part_info;
+      List_iterator<Create_field> def_it(column_rename_param.fields);
+      const bool part_field_list= !part_info->part_field_list.is_empty();
+      const bool subpart_field_list= !part_info->subpart_field_list.is_empty();
+      if (part_info->part_expr)
+        part_info->part_expr->walk(&Item::rename_fields_processor, 1,
+                                  &column_rename_param);
+      if (part_info->subpart_expr)
+        part_info->subpart_expr->walk(&Item::rename_fields_processor, 1,
+                                      &column_rename_param);
+      if (part_field_list || subpart_field_list)
+      {
+        while (Create_field *def= def_it++)
+        {
+          if (def->change.str)
+          {
+            if (part_field_list)
+              rename_field_in_list(def, &part_info->part_field_list);
+            if (subpart_field_list)
+              rename_field_in_list(def, &part_info->subpart_field_list);
+          } /* if (def->change.str) */
+        } /* while (def) */
+      } /* if (part_field_list || subpart_field_list) */
+    } /* if (part_info) */
+  }
+#endif
+
   dropped_sys_vers_fields &= VERS_SYSTEM_FIELD;
   if ((dropped_sys_vers_fields ||
        alter_info->flags & ALTER_DROP_PERIOD) &&