MDEV-16222 Assertion `0' failed in row_purge_remove_sec_if_poss_leaf on table with virtual columns and indexes

Cause
Stale thd->m_stmt_da->m_sql_errno which is from different invocation.

Fix
Reset error state before attempt to open table.

mysql-test/suite/innodb/r/purge_secondary_mdev-16222.result

@@ -0,0 +1,30 @@
+#
+# MDEV-16222 Assertion `0' failed in row_purge_remove_sec_if_poss_leaf on table with virtual columns and indexes
+#
+set @saved_frequency= @@global.innodb_purge_rseg_truncate_frequency;
+set global innodb_purge_rseg_truncate_frequency= 1;
+set @saved_dbug= @@global.debug_dbug;
+set global debug_dbug= "+d,ib_purge_virtual_mdev_16222_1,ib_purge_virtual_mdev_16222_2";
+create table t1 (
+pk serial, vb tinyblob as (b) virtual, b tinyblob,
+primary key(pk), index (vb(64)))
+engine innodb;
+insert ignore into t1 (b) values ('foo');
+select * into outfile 'load.data' from t1;
+load data infile 'load.data' replace into table t1;
+set debug_sync= "now WAIT_FOR latch_released";
+set global debug_dbug= "-d,ib_purge_virtual_mdev_16222_1";
+drop table t1;
+set debug_sync= "now SIGNAL drop_started WAIT_FOR got_no_such_table";
+create table t1 (
+pk serial, vb tinyblob as (b) virtual, b tinyblob,
+primary key(pk), index (vb(64)))
+engine innodb;
+insert ignore into t1 (b) values ('foo');
+select * into outfile 'load.data' from t1;
+load data infile 'load.data' replace into table t1;
+set debug_sync= "now WAIT_FOR got_no_such_table";
+set global debug_dbug= @saved_dbug;
+drop table t1;
+set global innodb_purge_rseg_truncate_frequency= @saved_frequency;
+set debug_sync= "RESET";

mysql-test/suite/innodb/t/purge_secondary_mdev-16222.opt

@@ -0,0 +1 @@
+--innodb-purge-threads=1

mysql-test/suite/innodb/t/purge_secondary_mdev-16222.test

@@ -0,0 +1,53 @@
+--source include/have_debug.inc
+--source include/have_innodb.inc
+
+--echo #
+--echo # MDEV-16222 Assertion `0' failed in row_purge_remove_sec_if_poss_leaf on table with virtual columns and indexes
+--echo #
+
+--let $datadir= `select @@datadir`
+set @saved_frequency= @@global.innodb_purge_rseg_truncate_frequency;
+set global innodb_purge_rseg_truncate_frequency= 1;
+set @saved_dbug= @@global.debug_dbug;
+set global debug_dbug= "+d,ib_purge_virtual_mdev_16222_1,ib_purge_virtual_mdev_16222_2";
+
+create table t1 (
+  pk serial, vb tinyblob as (b) virtual, b tinyblob,
+  primary key(pk), index (vb(64)))
+engine innodb;
+
+insert ignore into t1 (b) values ('foo');
+
+select * into outfile 'load.data' from t1;
+load data infile 'load.data' replace into table t1;
+
+set debug_sync= "now WAIT_FOR latch_released";
+set global debug_dbug= "-d,ib_purge_virtual_mdev_16222_1";
+drop table t1;
+--remove_file $datadir/test/load.data
+
+set debug_sync= "now SIGNAL drop_started WAIT_FOR got_no_such_table";
+
+create table t1 (
+  pk serial, vb tinyblob as (b) virtual, b tinyblob,
+  primary key(pk), index (vb(64)))
+engine innodb;
+
+insert ignore into t1 (b) values ('foo');
+
+select * into outfile 'load.data' from t1;
+load data infile 'load.data' replace into table t1;
+
+set debug_sync= "now WAIT_FOR got_no_such_table";
+# FIXME: Racing condition here:
+# 1. purge thread goes into sending got_no_such_table
+# 2. test thread finishes debug_sync= "RESET" below
+# 3. purge thread sends got_no_such_table
+set global debug_dbug= @saved_dbug;
+
+# cleanup
+drop table t1;
+--remove_file $datadir/test/load.data
+
+set global innodb_purge_rseg_truncate_frequency= @saved_frequency;
+set debug_sync= "RESET";

sql/sql_class.cc

@@ -4491,6 +4491,11 @@ unsigned long long thd_get_query_id(const MYSQL_THD thd)
   return((unsigned long long)thd->query_id);
 }
 
+void thd_clear_error(MYSQL_THD thd)
+{
+  thd->clear_error();
+}
+
 extern "C" const struct charset_info_st *thd_charset(MYSQL_THD thd)
 {
   return(thd->charset());

sql/sql_table.cc

@@ -2077,6 +2077,11 @@ bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
     }
   }
 
+  DBUG_EXECUTE_IF("ib_purge_virtual_mdev_16222_1",
+                  DBUG_ASSERT(!debug_sync_set_action(
+                                thd,
+                                STRING_WITH_LEN("now SIGNAL drop_started"))););
+
   /* mark for close and remove all cached entries */
   thd->push_internal_handler(&err_handler);
   error= mysql_rm_table_no_locks(thd, tables, if_exists, drop_temporary,

sql/table.cc

@@ -7682,6 +7682,7 @@ int TABLE::update_virtual_fields(handler *h, enum_vcol_update_mode update_mode)
 
 int TABLE::update_virtual_field(Field *vf)
 {
+  DBUG_ASSERT(!in_use->is_error());
   Query_arena backup_arena;
   DBUG_ENTER("TABLE::update_virtual_field");
   in_use->set_n_backup_active_arena(expr_arena, &backup_arena);

storage/innobase/handler/ha_innodb.cc

@@ -119,6 +119,8 @@ this program; if not, write to the Free Software Foundation, Inc.,
 
 extern "C" void thd_mark_transaction_to_rollback(MYSQL_THD thd, bool all);
 unsigned long long thd_get_query_id(const MYSQL_THD thd);
+void thd_clear_error(MYSQL_THD thd);
+
 TABLE *find_fk_open_table(THD *thd, const char *db, size_t db_len,
 			  const char *table, size_t table_len);
 MYSQL_THD create_thd();
@@ -21493,6 +21495,8 @@ static TABLE* innodb_acquire_mdl(THD* thd, dict_table_t* table)
 		return NULL;
 	}
 
+	DEBUG_SYNC(thd, "ib_purge_virtual_latch_released");
+
 	const table_id_t table_id = table->id;
 retry_mdl:
 	const bool unaccessible = !table->is_readable() || table->corrupted;
@@ -21504,6 +21508,10 @@ retry_mdl:
 
 	TABLE*	mariadb_table = open_purge_table(thd, db_buf, db_buf_len,
 						 tbl_buf, tbl_buf_len);
+	if (!mariadb_table)
+		thd_clear_error(thd);
+
+	DEBUG_SYNC(thd, "ib_purge_virtual_got_no_such_table");
 
 	table = dict_table_open_on_id(table_id, false, DICT_TABLE_OP_NORMAL);
 
@@ -21553,6 +21561,20 @@ fail:
 for purge thread */
 static TABLE* innodb_find_table_for_vc(THD* thd, dict_table_t* table)
 {
+	DBUG_EXECUTE_IF(
+		"ib_purge_virtual_mdev_16222_1",
+		DBUG_ASSERT(!debug_sync_set_action(
+			    thd,
+			    STRING_WITH_LEN("ib_purge_virtual_latch_released "
+					    "SIGNAL latch_released "
+					    "WAIT_FOR drop_started"))););
+	DBUG_EXECUTE_IF(
+		"ib_purge_virtual_mdev_16222_2",
+		DBUG_ASSERT(!debug_sync_set_action(
+			    thd,
+			    STRING_WITH_LEN("ib_purge_virtual_got_no_such_table "
+					    "SIGNAL got_no_such_table"))););
+
 	if (THDVAR(thd, background_thread)) {
 		/* Purge thread acquires dict_operation_lock while
 		processing undo log record. Release the dict_operation_lock
@@ -21888,6 +21910,7 @@ innobase_get_computed_value(
 	dbug_tmp_restore_column_map(mysql_table->write_set, old_write_set);
 
 	if (ret != 0) {
+	// FIXME: Why this error message is macro-hidden?
 #ifdef INNODB_VIRTUAL_DEBUG
 		ib::warn() << "Compute virtual column values failed ";
 		fputs("InnoDB: Cannot compute value for following record ",