MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))

Different fix. Don't allow Item_func_sp to be evaluated unless
all tables are prelocked.

Extend the test case to make sure Item_func_sp::val_str is called
(the table must have at least one row for that).

mysql-test/r/sp.result

@@ -8027,6 +8027,7 @@ CREATE TABLE `t1` (
 CREATE TABLE `t2` (
 `ap_close_to` varchar(8) COLLATE utf8_bin DEFAULT NULL
 ) DEFAULT CHARSET=utf8 COLLATE=utf8_bin ;
+insert t1 values (1);
 CREATE  FUNCTION `f1`(`P_DC_CD` VARBINARY(50), `P_SYS_DATE` DATETIME) RETURNS datetime
 DETERMINISTIC
 SQL SECURITY INVOKER

mysql-test/t/sp.test

@@ -9316,6 +9316,7 @@ CREATE TABLE `t1` (
 CREATE TABLE `t2` (
   `ap_close_to` varchar(8) COLLATE utf8_bin DEFAULT NULL
 ) DEFAULT CHARSET=utf8 COLLATE=utf8_bin ;
+insert t1 values (1);
 
 
 --delimiter $$

sql/item.h

@@ -3294,7 +3294,7 @@ public:
     if (result_type() == ROW_RESULT)
       orig_item->bring_value();
   }
-  virtual bool is_expensive() { return orig_item->is_expensive(); }
+  bool is_expensive() { return orig_item->is_expensive(); }
   bool is_expensive_processor(uchar *arg)
   { return orig_item->is_expensive_processor(arg); }
   bool check_vcol_func_processor(uchar *arg)

sql/item_func.cc

@@ -6778,7 +6778,8 @@ Item_func_sp::init_result_field(THD *thd)
 
 bool Item_func_sp::is_expensive()
 {
-  return !(m_sp->m_chistics->detistic);
+  return !m_sp->m_chistics->detistic ||
+          current_thd->locked_tables_mode < LTM_LOCK_TABLES;
 }