Fix for trigger.test failure in --debug mode.

We can't have Item_trigger_field as aggregated object inside of
sp_instr_set_trigger_field class since in this case its destructor
will be called twice. So instead let us create this Item separately
and store pointer to it in instruction object.

sql/sp_head.cc

@@ -1499,8 +1499,8 @@ sp_instr_set_trigger_field::execute(THD *thd, uint *nextp)
   DBUG_ENTER("sp_instr_set_trigger_field::execute");
   /* QQ: Still unsure what should we return in case of error 1 or -1 ? */
   if (!value->fixed && value->fix_fields(thd, 0, &value) ||
-      trigger_field.fix_fields(thd, 0, 0) ||
-      (value->save_in_field(trigger_field.field, 0) < 0))
+      trigger_field->fix_fields(thd, 0, 0) ||
+      (value->save_in_field(trigger_field->field, 0) < 0))
     res= -1;
   *nextp= m_ip + 1;
   DBUG_RETURN(res);
@@ -1510,7 +1510,7 @@ void
 sp_instr_set_trigger_field::print(String *str)
 {
   str->append("set ", 4);
-  trigger_field.print(str);
+  trigger_field->print(str);
   str->append(":=", 2);
   value->print(str);
 }

sql/sp_head.h

@@ -467,9 +467,9 @@ class sp_instr_set_trigger_field : public sp_instr
 public:
 
   sp_instr_set_trigger_field(uint ip, sp_pcontext *ctx,
-                             LEX_STRING field_name, Item *val)
+                             Item_trigger_field *trg_fld, Item *val)
     : sp_instr(ip, ctx),
-      trigger_field(Item_trigger_field::NEW_ROW, field_name.str),
+      trigger_field(trg_fld),
       value(val)
   {}
 
@@ -480,9 +480,8 @@ class sp_instr_set_trigger_field : public sp_instr
 
   virtual void print(String *str);
 
-  Item_trigger_field trigger_field;
-
 private:
+  Item_trigger_field *trigger_field;
   Item *value;
 }; // class sp_instr_trigger_field : public sp_instr
 

sql/sql_yacc.yy

@@ -7565,6 +7565,7 @@ sys_option_value:
           {
             /* We are in trigger and assigning value to field of new row */
             Item *it;
+            Item_trigger_field *trg_fld;
             sp_instr_set_trigger_field *i;
             if ($1)
             {
@@ -7585,17 +7586,19 @@ sys_option_value:
               it= new Item_null();
             }
 
-            if (!(i= new sp_instr_set_trigger_field(
-                lex->sphead->instructions(), lex->spcont,
-                $2.base_name, it)))
+            if (!(trg_fld= new Item_trigger_field(Item_trigger_field::NEW_ROW,
+                                                  $2.base_name.str)) ||
+                !(i= new sp_instr_set_trigger_field(
+                           lex->sphead->instructions(), lex->spcont,
+                           trg_fld, it)))
               YYABORT;
 
             /*
               Let us add this item to list of all Item_trigger_field
               objects in trigger.
             */
-            lex->trg_table_fields.link_in_list((byte *)&i->trigger_field,
-            (byte **)&i->trigger_field.next_trg_field);
+            lex->trg_table_fields.link_in_list((byte *)trg_fld,
+                                    (byte **)&trg_fld->next_trg_field);
 
             lex->sphead->add_instr(i);
           }