MDEV-26127 Assertion `err != DB_DUPLICATE_KEY' failed or InnoDB: Failing assertion: id != 0 on ALTER ... REBUILD PARTITION

During rebuild of partition, the partitioning engine calls
alter_close_table(), which does not unlock and close some table
instances of the target table.
Then, the engine fails to rename partitions because there are table
instances that are still locked.

Closing all the table instance of the target table fixes the bug.

mysql-test/suite/parts/inc/part_alter_values.inc

@@ -78,3 +78,11 @@ if (`SELECT IF('$engine' != 'InnoDB', 1, 0)`)
 
 --remove_files_wildcard $MYSQLTEST_VARDIR/tmp/mdev_27065 *
 --rmdir $MYSQLTEST_VARDIR/tmp/mdev_27065
+
+--echo #
+--echo # MDEV-26127 Assertion `err != DB_DUPLICATE_KEY' failed or InnoDB: Failing assertion: id != 0 on ALTER ... REBUILD PARTITION
+--echo #
+--eval CREATE TABLE t1 (c INT) ENGINE=$engine PARTITION BY KEY(c) PARTITIONS 4;
+LOCK TABLES t1 WRITE, t1 AS a READ;
+ALTER TABLE t1 REBUILD PARTITION p0;
+DROP TABLE t1;

mysql-test/suite/parts/r/partition_alter_innodb.result

@@ -61,3 +61,10 @@ PARTITION p1 VALUES LESS THAN MAXVALUE
 Warnings:
 Warning	1618	<DATA DIRECTORY> table option of old schema is ignored
 DROP TABLE t1;
+#
+# MDEV-26127 Assertion `err != DB_DUPLICATE_KEY' failed or InnoDB: Failing assertion: id != 0 on ALTER ... REBUILD PARTITION
+#
+CREATE TABLE t1 (c INT) ENGINE=InnoDB PARTITION BY KEY(c) PARTITIONS 4;;
+LOCK TABLES t1 WRITE, t1 AS a READ;
+ALTER TABLE t1 REBUILD PARTITION p0;
+DROP TABLE t1;

mysql-test/suite/parts/r/partition_alter_maria.result

@@ -95,3 +95,10 @@ PARTITION p1 VALUES LESS THAN MAXVALUE
 Warnings:
 Warning	1618	<INDEX DIRECTORY> table option of old schema is ignored
 DROP TABLE t2;
+#
+# MDEV-26127 Assertion `err != DB_DUPLICATE_KEY' failed or InnoDB: Failing assertion: id != 0 on ALTER ... REBUILD PARTITION
+#
+CREATE TABLE t1 (c INT) ENGINE=Aria PARTITION BY KEY(c) PARTITIONS 4;;
+LOCK TABLES t1 WRITE, t1 AS a READ;
+ALTER TABLE t1 REBUILD PARTITION p0;
+DROP TABLE t1;

mysql-test/suite/parts/r/partition_alter_myisam.result

@@ -68,6 +68,13 @@ PARTITION p1 VALUES LESS THAN MAXVALUE
 Warnings:
 Warning	1618	<INDEX DIRECTORY> table option of old schema is ignored
 DROP TABLE t2;
+#
+# MDEV-26127 Assertion `err != DB_DUPLICATE_KEY' failed or InnoDB: Failing assertion: id != 0 on ALTER ... REBUILD PARTITION
+#
+CREATE TABLE t1 (c INT) ENGINE=MyISAM PARTITION BY KEY(c) PARTITIONS 4;;
+LOCK TABLES t1 WRITE, t1 AS a READ;
+ALTER TABLE t1 REBUILD PARTITION p0;
+DROP TABLE t1;
 create table t1 ( c1 int, c2 int, c3 varchar(100)) delay_key_write=1
 partition by key(c1) (
 partition p01 data directory = 'MYSQL_TMP_DIR'

sql/sql_partition.cc

@@ -1,5 +1,5 @@
 /* Copyright (c) 2005, 2017, Oracle and/or its affiliates.
-   Copyright (c) 2009, 2018, MariaDB
+   Copyright (c) 2009, 2022, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -6929,14 +6929,29 @@ static void alter_partition_lock_handling(ALTER_PARTITION_PARAM_TYPE *lpt)
 
 static int alter_close_table(ALTER_PARTITION_PARAM_TYPE *lpt)
 {
+  THD *thd= lpt->thd;
+  TABLE_SHARE *share= lpt->table->s;
   DBUG_ENTER("alter_close_table");
 
-  if (lpt->table->db_stat)
+  TABLE *table= thd->open_tables;
-  {
+  do {
-    mysql_lock_remove(lpt->thd, lpt->thd->lock, lpt->table);
+    table= find_locked_table(table, share->db.str, share->table_name.str);
-    lpt->table->file->ha_close();
+    if (!table)
-    lpt->table->db_stat= 0;                        // Mark file closed
+    {
-  }
+      DBUG_RETURN(0);
+    }
+
+    if (table->db_stat)
+    {
+      mysql_lock_remove(thd, thd->lock, table);
+      if (int error= table->file->ha_close())
+      {
+        DBUG_RETURN(error);
+      }
+      table->db_stat= 0; // Mark file closed
+    }
+  } while ((table= table->next));
+
   DBUG_RETURN(0);
 }