Merge branch '11.8' into 12.0

main/statistics_json.result is updated for f8ba5ced55 (MDEV-36099)

The test uses 'delete from t1' in many places and then populates
the table again. The natural order of rows in a MyISAM table is well
defined and the test was implicitly relying on that.

before f8ba5ced55 delete was deleting rows one by one, using
ha_myisam::delete_row() because the connection was stuck in rbr mode.
This caused rows to be shown in the reverse insertion order (because of
the delete link list).

MDEV-36099 fixes this bug and the server now correctly uses
ha_myisam::delete_all_rows(). This makes rows to be shown in the
insertion order as expected.

sql/sql_class.cc

@@ -60,6 +60,7 @@
 #include "lock.h"
 #include "wsrep_mysqld.h"
 #include "sql_connect.h"
+#include "sql_cursor.h"                         //Select_materialize
 #ifdef WITH_WSREP
 #include "wsrep_thd.h"
 #include "wsrep_trans_observer.h"
@@ -910,7 +911,6 @@ THD::THD(my_thread_id id, bool is_wsrep_applier)
 
 #ifdef WITH_WSREP
   mysql_cond_init(key_COND_wsrep_thd, &COND_wsrep_thd, NULL);
-  wsrep_info[sizeof(wsrep_info) - 1] = '\0'; /* make sure it is 0-terminated */
 #endif
   /* Call to init() below requires fully initialized Open_tables_state. */
   reset_open_tables_state();
@@ -9054,6 +9054,12 @@ void Charset_loader_server::raise_not_applicable_error(const char *cs,
 }
 
 
+bool THD::is_cursor_execution() const
+{
+  return dynamic_cast<Select_materialize*>(this->lex->result);
+}
+
+
 LEX_CSTRING make_string(THD *thd, const char *start_ptr,
                         const char *end_ptr)
 {