MDEV-23248 Server crashes in mi_extra / ha_partition::loop_extra_alter upon REORGANIZE

This also fixes some issues with
MDEV-23730 s3.replication_partition 'innodb,mix' segv

The problem was that mysql_change_partitions() closes all handler files
in case of error, which was not properly reflected in
fast_alter_partition_table(). This caused handle_alter_part_error() to
try to close already closed tables, which caused the crash.

Fixed fast_alter_partion_table() to reflect when tables are opened.
I also fixed that ha_partition::change_partitions() resets m_new_file in
case of errors.
Either of the above changes fixes the issue, but both are needed to ensure
that the code works as expected.

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

+#
+# MDEV-23248 Server crashes in mi_extra /
+# ha_partition::loop_extra_alter upon REORGANIZE
+#
+CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM PARTITION BY RANGE (a) SUBPARTITION BY HASH (a) SUBPARTITIONS 70 (PARTITION p1 VALUES LESS THAN (100), PARTITION p2 VALUES LESS THAN MAXVALUE);
+INSERT INTO t1 SELECT 4, 6 FROM seq_1_to_131072;
+UPDATE t1 SET a = 7;
+set @org_debug=@@debug_dbug;
+set @@debug_dbug="+d,debug_abort_copy_partitions";
+ALTER TABLE t1 REORGANIZE PARTITION p1,p2 INTO (PARTITION p1 VALUES LESS THAN (5), PARTITION p2 VALUES LESS THAN MAXVALUE);
+ERROR 42000: Table 't1' uses an extension that doesn't exist in this MariaDB version
+set @@debug_dbug=@org_debug;
+DROP TABLE t1;

mysql-test/suite/parts/t/reorganize.test

+--source include/have_sequence.inc
+--source include/have_partition.inc
+--source include/have_debug.inc
+
+--echo #
+--echo # MDEV-23248 Server crashes in mi_extra /
+--echo # ha_partition::loop_extra_alter upon REORGANIZE
+--echo #
+
+CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM PARTITION BY RANGE (a) SUBPARTITION BY HASH (a) SUBPARTITIONS 70 (PARTITION p1 VALUES LESS THAN (100), PARTITION p2 VALUES LESS THAN MAXVALUE);
+INSERT INTO t1 SELECT 4, 6 FROM seq_1_to_131072;
+UPDATE t1 SET a = 7;
+
+set @org_debug=@@debug_dbug;
+set @@debug_dbug="+d,debug_abort_copy_partitions";
+--error ER_UNSUPPORTED_EXTENSION
+ALTER TABLE t1 REORGANIZE PARTITION p1,p2 INTO (PARTITION p1 VALUES LESS THAN (5), PARTITION p2 VALUES LESS THAN MAXVALUE);
+set @@debug_dbug=@org_debug;
+
+DROP TABLE t1;

sql/ha_partition.cc

@@ -2025,6 +2025,7 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
     DBUG_ASSERT(part_elem->part_state == PART_TO_BE_REORGED);
     part_elem->part_state= PART_TO_BE_DROPPED;
   }
+  DBUG_ASSERT(m_new_file == 0);
   m_new_file= new_file_array;
   if (unlikely((error= copy_partitions(copied, deleted))))
   {
@@ -2033,6 +2034,7 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
       They will later be deleted through the ddl-log.
     */
     cleanup_new_partition(part_count);
+    m_new_file= 0;
   }
   DBUG_RETURN(error);
 }
@@ -2124,6 +2126,8 @@ int ha_partition::copy_partitions(ulonglong * const copied,
     file->ha_rnd_end();
     reorg_part++;
   }
+  DBUG_EXECUTE_IF("debug_abort_copy_partitions",
+                  DBUG_RETURN(HA_ERR_UNSUPPORTED); );
   DBUG_RETURN(FALSE);
 error:
   m_reorged_file[reorg_part]->ha_rnd_end();

sql/sql_partition.cc

@@ -7487,11 +7487,11 @@ uint fast_alter_partition_table(THD *thd, TABLE *table,
         mysql_write_frm(lpt, WFRM_WRITE_SHADOW) ||
         ERROR_INJECT_CRASH("crash_change_partition_2") ||
         ERROR_INJECT_ERROR("fail_change_partition_2") ||
-        (close_table_on_failure= TRUE, FALSE) ||
         write_log_add_change_partition(lpt) ||
         ERROR_INJECT_CRASH("crash_change_partition_3") ||
         ERROR_INJECT_ERROR("fail_change_partition_3") ||
         mysql_change_partitions(lpt) ||
+        (close_table_on_failure= TRUE, FALSE) ||
         ERROR_INJECT_CRASH("crash_change_partition_4") ||
         ERROR_INJECT_ERROR("fail_change_partition_4") ||
         wait_while_table_is_used(thd, table, HA_EXTRA_NOT_USED) ||