MDEV-29886 Assertion !index->table->is_temporary() failed in CHECK TABLE

ha_innobase::check(): Do not enable READ UNCOMMITTED isolation level
for temporary tables, because it would report index count mismatch
for secondary indexes.

row_check_index(): Ignore EXTENDED for temporary tables, because
the tables are private to the current connection and there will be
no purge of committed transaction history.

mysql-test/suite/innodb/r/temporary_table.result

@@ -775,3 +775,18 @@ INSERT INTO t VALUES (1);
 START TRANSACTION READ ONLY;
 UPDATE t SET a = NULL;
 ROLLBACK;
+DROP TABLE t;
+#
+# MDEV-29886 Assertion !index->table->is_temporary() failed
+# in trx_undo_prev_version_build upon CHECK
+#
+CREATE TEMPORARY TABLE t (a INT, KEY(a)) ENGINE=InnoDB SELECT 1;
+UPDATE t SET a=2;
+CHECK TABLE t;
+Table	Op	Msg_type	Msg_text
+test.t	check	status	OK
+CHECK TABLE t EXTENDED;
+Table	Op	Msg_type	Msg_text
+test.t	check	status	OK
+DROP TEMPORARY TABLE t;
+# End of 10.6 tests

mysql-test/suite/innodb/t/temporary_table.test

@@ -613,3 +613,15 @@ INSERT INTO t VALUES (1);
 START TRANSACTION READ ONLY;
 UPDATE t SET a = NULL;
 ROLLBACK;
+DROP TABLE t;
+
+--echo #
+--echo # MDEV-29886 Assertion !index->table->is_temporary() failed
+--echo # in trx_undo_prev_version_build upon CHECK
+--echo #
+CREATE TEMPORARY TABLE t (a INT, KEY(a)) ENGINE=InnoDB SELECT 1;
+UPDATE t SET a=2;
+CHECK TABLE t;
+CHECK TABLE t EXTENDED;
+DROP TEMPORARY TABLE t;
+--echo # End of 10.6 tests

storage/innobase/handler/ha_innodb.cc

@@ -15220,6 +15220,7 @@ ha_innobase::check(
 	of records in some index; to play safe, we normally use
 	REPEATABLE READ here */
 	m_prebuilt->trx->isolation_level = high_level_read_only
+		&& !m_prebuilt->table->is_temporary()
 		? TRX_ISO_READ_UNCOMMITTED
 		: TRX_ISO_REPEATABLE_READ;
 

storage/innobase/row/row0sel.cc

@@ -6228,6 +6228,7 @@ dberr_t row_check_index(row_prebuilt_t *prebuilt, ulint *n_rows)
   ReadView check_table_extended_view;
   ReadView &view=
     prebuilt->need_to_access_clustered &&
+    !prebuilt->table->is_temporary() &&
     prebuilt->trx->isolation_level != TRX_ISO_READ_UNCOMMITTED
     ? check_table_extended_view : prebuilt->trx->read_view;
   if (&view == &check_table_extended_view)