MDEV-4756: 10.0-monty tree: log_state.test fails

- make the test output stable
- make Log_to_csv_event_handler::log_slow() to write the value 
  of thd->thread_id (it didn't, and so 0 was always logged).

mysql-test/r/log_state.result

@@ -45,7 +45,7 @@ select sleep(@long_query_time + 1);
 sleep(@long_query_time + 1)
 0
 select * from mysql.slow_log where sql_text NOT LIKE '%slow_log%';
-start_time	user_host	query_time	lock_time	rows_sent	rows_examined	db	last_insert_id	insert_id	server_id	sql_text
+start_time	user_host	query_time	lock_time	rows_sent	rows_examined	db	last_insert_id	insert_id	server_id	sql_text	thread_id
 # Switch to connection default
 set global slow_query_log= ON;
 # Switch to connection con1
@@ -54,8 +54,8 @@ select sleep(@long_query_time + 1);
 sleep(@long_query_time + 1)
 0
 select * from mysql.slow_log where sql_text NOT LIKE '%slow_log%';
-start_time	user_host	query_time	lock_time	rows_sent	rows_examined	db	last_insert_id	insert_id	server_id	sql_text
-TIMESTAMP	USER_HOST	QUERY_TIME	00:00:00.000000	1	0	test	0	0	1	select sleep(@long_query_time + 1)
+start_time	user_host	query_time	lock_time	rows_sent	rows_examined	db	last_insert_id	insert_id	server_id	sql_text	thread_id
+TIMESTAMP	USER_HOST	QUERY_TIME	00:00:00.000000	1	0	test	0	0	1	select sleep(@long_query_time + 1)	THREAD_ID
 # Switch to connection default
 show global variables
 where Variable_name = 'log' or Variable_name = 'log_slow_queries' or

mysql-test/t/log_state.test

@@ -48,7 +48,7 @@ connection con1;
 set @long_query_time = 2;
 set session long_query_time = @long_query_time;
 select sleep(@long_query_time + 1);
---replace_column 1 TIMESTAMP 2 USER_HOST 3 QUERY_TIME
+--replace_column 1 TIMESTAMP 2 USER_HOST 3 QUERY_TIME 12 THREAD_ID
 select * from mysql.slow_log where sql_text NOT LIKE '%slow_log%';
 --echo # Switch to connection default
 connection default;
@@ -58,7 +58,7 @@ set global slow_query_log= ON;
 connection con1;
 set session long_query_time = @long_query_time;
 select sleep(@long_query_time + 1);
---replace_column 1 TIMESTAMP 2 USER_HOST 3 QUERY_TIME
+--replace_column 1 TIMESTAMP 2 USER_HOST 3 QUERY_TIME 12 THREAD_ID
 select * from mysql.slow_log where sql_text NOT LIKE '%slow_log%';
 --echo # Switch to connection default
 connection default;

sql/log.cc

@@ -895,6 +895,9 @@ bool Log_to_csv_event_handler::
   if (table->field[10]->store(sql_text, sql_text_len, client_cs) < 0)
     goto err;
 
+  if (table->field[11]->store((longlong) thd->thread_id, TRUE))
+    goto err;
+
   /* log table entries are not replicated */
   if (table->file->ha_write_row(table->record[0]))
     goto err;