From c82f3f1b041b877ac0a149e594756a61d1f6ef48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@mariadb.com>
Date: Mon, 14 Nov 2022 13:08:00 +0200
Subject: [PATCH] MDEV-29978 Corruption errors upon CHECK on temporary InnoDB
 table

row_check_index(): Treat secondary indexes of temporary tables as if
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED
is in effect. That is, only consider the delete-mark and nothing else.
---
 .../suite/innodb/r/temporary_table.result     | 12 ++++++++++++
 .../suite/innodb/t/temporary_table.test       | 11 +++++++++++
 storage/innobase/row/row0sel.cc               | 19 +++++++++----------
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/mysql-test/suite/innodb/r/temporary_table.result b/mysql-test/suite/innodb/r/temporary_table.result
index a8a073cb257..ffcee726f0d 100644
--- a/mysql-test/suite/innodb/r/temporary_table.result
+++ b/mysql-test/suite/innodb/r/temporary_table.result
@@ -789,4 +789,16 @@ CHECK TABLE t EXTENDED;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
 DROP TEMPORARY TABLE t;
+#
+# MDEV-29978 Corruption errors upon CHECK on temporary InnoDB table
+#
+CREATE TEMPORARY TABLE t (f INT UNIQUE) ENGINE=InnoDB;
+INSERT INTO t (f) VALUES (1),(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
diff --git a/mysql-test/suite/innodb/t/temporary_table.test b/mysql-test/suite/innodb/t/temporary_table.test
index 0cc3b29feb1..5d7e5d51696 100644
--- a/mysql-test/suite/innodb/t/temporary_table.test
+++ b/mysql-test/suite/innodb/t/temporary_table.test
@@ -624,4 +624,15 @@ UPDATE t SET a=2;
 CHECK TABLE t;
 CHECK TABLE t EXTENDED;
 DROP TEMPORARY TABLE t;
+
+--echo #
+--echo # MDEV-29978 Corruption errors upon CHECK on temporary InnoDB table
+--echo #
+
+CREATE TEMPORARY TABLE t (f INT UNIQUE) ENGINE=InnoDB;
+INSERT INTO t (f) VALUES (1),(2);
+CHECK TABLE t;
+CHECK TABLE t EXTENDED;
+DROP TEMPORARY TABLE t;
+
 --echo # End of 10.6 tests
diff --git a/storage/innobase/row/row0sel.cc b/storage/innobase/row/row0sel.cc
index 82079cbd06b..f65b47c0af8 100644
--- a/storage/innobase/row/row0sel.cc
+++ b/storage/innobase/row/row0sel.cc
@@ -6300,14 +6300,16 @@ rec_loop:
     goto next_rec;
   }
 
-  if (index->is_clust())
+  if (prebuilt->table->is_temporary())
+  {
+  count_or_not:
+    if (rec_deleted)
+      goto next_rec;
+  }
+  else if (index->is_clust())
   {
     if (prebuilt->trx->isolation_level == TRX_ISO_READ_UNCOMMITTED)
-    {
-      if (!rec_deleted)
-        goto count_row;
-      goto next_rec;
-    }
+      goto count_or_not;
 
     trx_id_t rec_trx_id= row_get_rec_trx_id(rec, index, offsets);
 
@@ -6371,10 +6373,7 @@ rec_loop:
                           ER_NOT_KEYFILE, "InnoDB: %s", w.m_oss.str().c_str());
     }
 
-    if (!rec_deleted)
-      goto count_row;
-
-    goto next_rec;
+    goto count_or_not;
   }
   else if (const trx_id_t page_trx_id= page_get_max_trx_id(page_align(rec)))
   {