BUG#40704 main.events_restart fails sporadically in pushbuild: "server has gone away"

mysqltest command 'shutdown_server' is supposed to shutdown the server
and wait for it to be gone, and kill it when timeout. But because the
arguments passed to my_kill were in the wrong order, 'shutdown_server'
does not wait nor kill the server at all. So after 'shutdown_server',
the server is still running, and the server may still accepting
connections.

client/mysqltest.cc

@@ -4177,9 +4177,9 @@ void do_shutdown_server(struct st_command *command)
 
   /* Check that server dies */
   while(timeout--){
-    if (my_kill(0, pid) < 0){
+    if (my_kill(pid, 0) < 0){
       DBUG_PRINT("info", ("Process %d does not exist anymore", pid));
-      break;
+      DBUG_VOID_RETURN;
     }
     DBUG_PRINT("info", ("Sleeping, timeout: %d", timeout));
     my_sleep(1000000L);
@@ -4187,7 +4187,7 @@ void do_shutdown_server(struct st_command *command)
 
   /* Kill the server */
   DBUG_PRINT("info", ("Killing server, pid: %d", pid));
-  (void)my_kill(9, pid);
+  (void)my_kill(pid, 9);
 
   DBUG_VOID_RETURN;
 

mysql-test/include/mtr_warnings.sql

@@ -102,6 +102,7 @@ INSERT INTO global_suppressions VALUES
  ("Failed to open log"),
  ("Failed to open the existing master info file"),
  ("Forcing shutdown of [0-9]* plugins"),
+ ("Forcing close of thread"),
 
  /*
    Due to timing issues, it might be that this warning

mysql-test/include/restart_mysqld.inc

@@ -9,9 +9,6 @@ EOF
 # it 10 seconds to die before zapping it
 shutdown_server 10;
 
-# Check server is gone
---source include/wait_until_disconnected.inc
-
 # Write file to make mysql-test-run.pl start up the server again
 --append_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
 restart