Bug#8057

  Fix crash with LAST_INSERT_ID() in UPDATE,
  Tests included,

mysql-test/r/update.result

@@ -212,3 +212,10 @@ insert into t1 values (1, "t1c2-1", 10), (2, "t1c2-2", 20);
 update t1 left join t2 on t1.c1 = t2.c1 set t2.c2 = "t2c2-1";
 update t1 left join t2 on t1.c1 = t2.c1 set t2.c2 = "t2c2-1" where t1.c3 = 10;
 drop table t1, t2;
+create table t1 (id int not null auto_increment primary key, id_str varchar(32));
+insert into t1 (id_str) values ("test");
+update t1 set id_str = concat(id_str, id) where id = last_insert_id();
+select * from t1;
+id	id_str
+1	test1
+drop table t1;

mysql-test/t/update.test

@@ -170,3 +170,12 @@ insert into t1 values (1, "t1c2-1", 10), (2, "t1c2-2", 20);
 update t1 left join t2 on t1.c1 = t2.c1 set t2.c2 = "t2c2-1";
 update t1 left join t2 on t1.c1 = t2.c1 set t2.c2 = "t2c2-1" where t1.c3 = 10;
 drop table t1, t2;
+
+#
+# Bug #8057
+#
+create table t1 (id int not null auto_increment primary key, id_str varchar(32));
+insert into t1 (id_str) values ("test");
+update t1 set id_str = concat(id_str, id) where id = last_insert_id();
+select * from t1;
+drop table t1;

sql/item_func.cc

@@ -2284,14 +2284,10 @@ longlong Item_func_last_insert_id::val_int()
     longlong value=args[0]->val_int();
     current_thd->insert_id(value);
     null_value=args[0]->null_value;
-    return value;
   }
   else
-  {
-    Item *it= get_system_var(current_thd, OPT_SESSION, "last_insert_id", 14,
-			     "last_insert_id()");
-    return it->val_int();
-  }
+    current_thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
+  return current_thd->insert_id();
 }
 
 /* This function is just used to test speed of different functions */