MDEV-8836 - Server crashed in my_copy_8bit on querying I_S.PROCESSLIST

Fixed race condition in code filling INFORMATION_SCHEMA.PROCESSLIST.INFO_BINARY. When loading query string/length of another connection one must have LOCK_thd_data locked.

Author: svoj

sql/sql_show.cc

@@ -2888,6 +2888,15 @@ int fill_schema_processlist(THD* thd, TABLE_LIST* tables, COND* cond)
  table->field[7]->set_notnull();
  }
 
+ /* INFO_BINARY */
+ if (tmp->query())
+ {
+ table->field[15]->store(tmp->query(),
+ MY_MIN(PROCESS_LIST_INFO_WIDTH,
+ tmp->query_length()), &my_charset_bin);
+ table->field[15]->set_notnull();
+ }
+
  /*
  Progress report. We need to do this under a lock to ensure that all
  is from the same stage.
@@ -2916,15 +2925,6 @@ int fill_schema_processlist(THD* thd, TABLE_LIST* tables, COND* cond)
  /* QUERY_ID */
  table->field[14]->store(tmp->query_id, TRUE);
 
- /* INFO_BINARY */
- if (tmp->query())
- {
- table->field[15]->store(tmp->query(),
- MY_MIN(PROCESS_LIST_INFO_WIDTH,
- tmp->query_length()), &my_charset_bin);
- table->field[15]->set_notnull();
- }
-
  table->field[16]->store(tmp->os_thread_id);
 
  if (schema_table_store_record(thd, table))