[#MDEV-8353] STOP SLAVE may hang when replication is in inconsistent state

There is this slave where replication failed a long time ago, but for some reason is completely impossible to stop. Here is the output of SHOW SLAVE STATUS:

mysql> show slave status\G

*************************** 1. row ***************************

               Slave_IO_State:

                  Master_Host: (redacted)

                  Master_User: replicate

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.031549

          Read_Master_Log_Pos: 350895547

               Relay_Log_File: mysql-relay-bin.036016

                Relay_Log_Pos: 350557624

        Relay_Master_Log_File: mysql-bin.031549

             Slave_IO_Running: No

            Slave_SQL_Running: Yes

              Replicate_Do_DB:

          Replicate_Ignore_DB:

           Replicate_Do_Table:

       Replicate_Ignore_Table:

      Replicate_Wild_Do_Table:

  Replicate_Wild_Ignore_Table:

                   Last_Errno: 0

                   Last_Error:

                 Skip_Counter: 0

          Exec_Master_Log_Pos: 350557340

              Relay_Log_Space: 350896811

              Until_Condition: None

               Until_Log_File:

                Until_Log_Pos: 0

           Master_SSL_Allowed: No

           Master_SSL_CA_File:

           Master_SSL_CA_Path:

              Master_SSL_Cert:

            Master_SSL_Cipher:

               Master_SSL_Key:

        Seconds_Behind_Master: NULL

Master_SSL_Verify_Server_Cert: No

                Last_IO_Errno: 1236

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'

               Last_SQL_Errno: 0

               Last_SQL_Error:

  Replicate_Ignore_Server_Ids:

             Master_Server_Id: 42343306

150622 14:28:23 [Warning] Slave SQL: Request to stop slave SQL Thread received while applying a group that has non-transactional changes; waiting for completion of the group ... , Error_code : 0

When this is done, this causes threads in KILL state to appear, then as slave will never stop it is necessary to SIGKILL mysqld. unfortunately skip-slave-start seems to be ignored, as the IO thread is not running, but mysqld considers that the slave is still running and I can't reset it (even though I could probably just remove the master.info file and be done with it)

[MDEV-8353] STOP SLAVE may hang when replication is in inconsistent state Created: 2015-06-22 Updated: 2019-04-06
Status:	Open
Project:	MariaDB Server
Component/s:	Replication
Affects Version/s:	5.5.42
Fix Version/s:	5.5

[MDEV-8353] STOP SLAVE may hang when replication is in inconsistent state Created: 2015-06-22 Updated: 2019-04-06