Fix for Bug#42602 main.status: random failures

+ minor improvements

mysql-test/t/status.test

@@ -4,6 +4,9 @@
 # embedded server causes different stat
 -- source include/not_embedded.inc
 
+# Save the initial number of concurrent sessions
+--source include/count_sessions.inc
+
 # Disable concurrent inserts to avoid sporadic test failures as it might
 # affect the the value of variables used throughout the test case.
 set @old_concurrent_insert= @@global.concurrent_insert;
@@ -88,7 +91,7 @@ show status like 'last_query_cost';
 drop table t1;
 
 #
-# Test for Bug #15933 max_used_connections is wrong after FLUSH STATUS
+# Test for Bug#15933 max_used_connections is wrong after FLUSH STATUS
 # if connections are cached
 #
 #
@@ -188,7 +191,7 @@ disconnect con1;
 
 
 #
-# Bug #30377: EXPLAIN loses last_query_cost when used with UNION
+# Bug#30377 EXPLAIN loses last_query_cost when used with UNION
 #
 
 CREATE TABLE t1 ( a INT );
@@ -261,7 +264,7 @@ drop function f1;
 show status like 'Com%function';
 
 #
-# Bug#37908: Skipped access right check caused server crash.
+# Bug#37908 Skipped access right check caused server crash.
 #
 connect (root, localhost, root,,test);
 connection root;
@@ -280,13 +283,13 @@ delimiter ;|
 connect (user1,localhost,mysqltest_1,,test);
 connection user1;
 
---error 1142
+--error ER_TABLEACCESS_DENIED_ERROR
 select * from db37908.t1;
---error 1142
+--error ER_TABLEACCESS_DENIED_ERROR
 show status where variable_name ='uptime' and 2 in (select * from db37908.t1);
---error 1142
+--error ER_TABLEACCESS_DENIED_ERROR
 show procedure status where name ='proc37908' and 1 in (select f1 from db37908.t1);
---error 1142
+--error ER_TABLEACCESS_DENIED_ERROR
 show function status where name ='func37908' and 1 in (select func37908());
 
 connection default;
@@ -297,6 +300,8 @@ drop procedure proc37908;
 drop function func37908;
 REVOKE ALL PRIVILEGES, GRANT OPTION FROM mysqltest_1@localhost;
 DROP USER mysqltest_1@localhost;
+# Wait till we reached the initial number of concurrent sessions
+--source include/wait_until_count_sessions.inc
 
 #
 # Bug#41131 "Questions" fails to increment - ignores statements instead stored procs
@@ -339,3 +344,7 @@ DROP FUNCTION f1;
 # Restore global concurrent_insert value. Keep in the end of the test file.
 --connection default
 set @@global.concurrent_insert= @old_concurrent_insert;
+
+# Wait till we reached the initial number of concurrent sessions
+--source include/wait_until_count_sessions.inc
+