MDEV-33101 Server crashes when starting the server with...

MDEV-33101 Server crashes when starting the server with innodb-force-recovery=6 and enabling the innodb_truncate_temporary_tablespace_now variable

The issue is introduced by "MDEV-28699: Shrink temporary tablespaces
without restart". SRV_FORCE_NO_LOG_REDO forces server to read only mode
and we don't initialize temporary tablespace in read only mode.

solution: innodb_truncate_temporary_tablespace_now should be no-op in
read only mode.

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

@@ -29,6 +29,9 @@ UPDATE t SET a=3 WHERE a=1;
 # Starting with MariaDB 10.2, innodb_read_only implies READ UNCOMMITTED.
 # In earlier versions, this would return the last committed version
 # (empty table)!
+SHOW VARIABLES LIKE "innodb_read_only";
+Variable_name	Value
+innodb_read_only	ON
 SELECT * FROM t;
 a
 3
@@ -39,6 +42,8 @@ a
 SET GLOBAL innodb_max_purge_lag_wait=0;
 INSERT INTO mysql.innodb_index_stats
 SELECT * FROM mysql.innodb_index_stats LIMIT 0;
+Test Temp tablespace truncate in read only mode
+SET GLOBAL innodb_truncate_temporary_tablespace_now=1;
 # restart
 SELECT * FROM t;
 a

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

+# MDEV-33101 Server crashes when starting the server with
+# innodb-force-recovery=6 and enabling the
+# innodb_truncate_temporary_tablespace_now variable
+# restart: --innodb-force-recovery=6
+SHOW VARIABLES LIKE "innodb_read_only";
+Variable_name	Value
+innodb_read_only	ON
+SET GLOBAL innodb_truncate_temporary_tablespace_now=1;
 # restart
 CREATE TEMPORARY TABLE t1(f1 INT NOT NULL,
 f2 INT NOT NULL)ENGINE=InnoDB;

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

@@ -35,12 +35,15 @@ UPDATE t SET a=3 WHERE a=1;
 --echo # Starting with MariaDB 10.2, innodb_read_only implies READ UNCOMMITTED.
 --echo # In earlier versions, this would return the last committed version
 --echo # (empty table)!
+SHOW VARIABLES LIKE "innodb_read_only";
 SELECT * FROM t;
 SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
 SELECT * FROM t;
 SET GLOBAL innodb_max_purge_lag_wait=0;
 INSERT INTO mysql.innodb_index_stats
 SELECT * FROM mysql.innodb_index_stats LIMIT 0;
+--echo Test Temp tablespace truncate in read only mode
+SET GLOBAL innodb_truncate_temporary_tablespace_now=1;
 --let $restart_parameters=
 --source include/restart_mysqld.inc
 SELECT * FROM t;

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

 --source include/have_innodb.inc
 --source include/have_sequence.inc
 
+--echo # MDEV-33101 Server crashes when starting the server with
+--echo # innodb-force-recovery=6 and enabling the
+--echo # innodb_truncate_temporary_tablespace_now variable
+
+--let $restart_parameters=--innodb-force-recovery=6
+--source include/restart_mysqld.inc
+SHOW VARIABLES LIKE "innodb_read_only";
+SET GLOBAL innodb_truncate_temporary_tablespace_now=1;
+
+--let $restart_parameters=
 --source include/restart_mysqld.inc
 CREATE TEMPORARY TABLE t1(f1 INT NOT NULL,
 			  f2 INT NOT NULL)ENGINE=InnoDB;

storage/innobase/handler/ha_innodb.cc

@@ -18482,7 +18482,8 @@ static
 void
 innodb_trunc_temp_space_update(THD*, st_mysql_sys_var*, void*, const void* save)
 {
-  if (!*static_cast<const my_bool*>(save))
+  /* Temp tablespace is not initialized in read only mode. */
+  if (!*static_cast<const my_bool*>(save) || srv_read_only_mode)
     return;
   mysql_mutex_unlock(&LOCK_global_system_variables);
   fsp_shrink_temp_space();