MDEV-21187: log_slow_filter="" logs queries not using indexes

Consistent with MDEV-4206 and empty log_slow_filter still means
no explict filtering. Since 21518ab2e453 however the
log_queries_not_using_indexes became stored in the same variable.

As we need to test for the absense of log_queries_not_using_indexes
the SERVER_QUERY_NO_INDEX USED part of log_slow_statement, the empty
criteria resulted in an always true to log queries not using indexes if
log_slow_filter was set to empty.

Adjusted the log_slow.test for MDEV-4206 as slow_log_query has been
global and session for a while and it was relying on the MDEV-21187
buggy behavior to detect a slow query.

Reviewer: Monty

1 files changed, 19 insertions, 2 deletions

diff --git a/mysql-test/main/log_slow.test b/mysql-test/main/log_slow.test
index b51777d859e..d2e314cf667 100644
--- a/mysql-test/main/log_slow.test
+++ b/mysql-test/main/log_slow.test
@@ -50,14 +50,14 @@ flush slow logs;
 # MDEV-4206 (empty filter should be no filter)
 set long_query_time=0.1;
 set log_slow_filter='';
-set global slow_query_log=1;
+set slow_query_log=1;
 set global log_output='TABLE';
 select sleep(0.5);
 select count(*) FROM mysql.slow_log;
 
 # Reset used variables
 set @@long_query_time=default;
-set global slow_query_log= @org_slow_query_log;
+set @@slow_query_log=default;
 set @@log_slow_filter=default;
 set @@log_slow_verbosity=default;
 set global log_output= default;
@@ -102,3 +102,20 @@ SET log_slow_filter=DEFAULT;
 
 SET @@long_query_time=default;
 SET GLOBAL slow_query_log= @org_slow_query_log;
+
+--echo #
+--echo # MDEV-21187: log_slow_filter="" logs queries not using indexes
+--echo #
+
+flush status;
+create table t (id int);
+insert into t values (1),(4);
+set log_slow_filter='';
+select * from t;
+show session status like 'Slow_queries';
+
+drop table t;
+
+--echo #
+--echo # End of 10.3 tests
+--echo #