MDEV-32532 Assertion failure in ddl_log_increment_phase_no_lock upon ..

The reason for the bug was that spider plugin does some ALTER TABLE
commands before recovery is done, which was not expected.

Fixed by resetting the ddl_log lists in create_ddl_log()

sql/ddl_log.cc

@@ -181,6 +181,8 @@ static constexpr unsigned DDL_LOG_BACKUP_OFFSET_POS= 8;
 /* Sum of the above variables */
 static constexpr unsigned DDL_LOG_HEADER_SIZE= 4+2+2+1;
 
+static void ddl_log_free_lists();
+
 /**
   Sync the ddl log file.
 
@@ -734,6 +736,7 @@ static bool create_ddl_log()
   char file_name[FN_REFLEN];
   DBUG_ENTER("create_ddl_log");
 
+  ddl_log_free_lists();
   global_ddl_log.open= 0;
   global_ddl_log.created= 1;
   global_ddl_log.num_entries= 0;
@@ -2826,24 +2829,11 @@ int ddl_log_execute_recovery()
 }
 
 
-/**
-  Release all memory allocated to the ddl log and delete the ddl log
-*/
-
-void ddl_log_release()
+static void ddl_log_free_lists()
 {
-  char file_name[FN_REFLEN];
-  DDL_LOG_MEMORY_ENTRY *free_list;
-  DDL_LOG_MEMORY_ENTRY *used_list;
-  DBUG_ENTER("ddl_log_release");
+  DDL_LOG_MEMORY_ENTRY *free_list= global_ddl_log.first_free;
+  DDL_LOG_MEMORY_ENTRY *used_list= global_ddl_log.first_used;
 
-  if (!global_ddl_log.initialized)
-    DBUG_VOID_RETURN;
-
-  global_ddl_log.initialized= 0;
-
-  free_list= global_ddl_log.first_free;
-  used_list= global_ddl_log.first_used;
   while (used_list)
   {
     DDL_LOG_MEMORY_ENTRY *tmp= used_list->next_log_entry;
@@ -2856,6 +2846,25 @@ void ddl_log_release()
     my_free(free_list);
     free_list= tmp;
   }
+  global_ddl_log.first_free= global_ddl_log.first_used= 0;
+}
+
+
+/**
+  Release all memory allocated to the ddl log and delete the ddl log
+*/
+
+void ddl_log_release()
+{
+  char file_name[FN_REFLEN];
+  DBUG_ENTER("ddl_log_release");
+
+  if (!global_ddl_log.initialized)
+    DBUG_VOID_RETURN;
+
+  global_ddl_log.initialized= 0;
+  ddl_log_free_lists();
+
   my_free(global_ddl_log.file_entry_buf);
   global_ddl_log.file_entry_buf= 0;
   close_ddl_log();

storage/spider/mysql-test/spider/bugfix/r/ddl_log.result

+# restart: --plugin-load-add=ha_spider
+#
+# MDEV-32532 Assertion failure in ddl_log_increment_phase_no_lock upon
+# partition operations with spider plugin loaded
+#
+CREATE TABLE t1 (a INT) PARTITION BY HASH (a) PARTITIONS 2;
+ALTER TABLE t1 REBUILD PARTITION p0;
+drop table t1;
+#
+# End of 10.10
+#
+uninstall plugin spider;

storage/spider/mysql-test/spider/bugfix/t/ddl_log.test

+--source include/have_partition.inc
+--let $restart_parameters= --plugin-load-add=ha_spider
+--source include/restart_mysqld.inc
+
+--echo #
+--echo # MDEV-32532 Assertion failure in ddl_log_increment_phase_no_lock upon
+--echo # partition operations with spider plugin loaded
+--echo #
+CREATE TABLE t1 (a INT) PARTITION BY HASH (a) PARTITIONS 2;
+ALTER TABLE t1 REBUILD PARTITION p0;
+drop table t1;
+
+--echo #
+--echo # End of 10.10
+--echo #
+
+uninstall plugin spider;