don't cast random items to Item_result_field*

do it only for items that inherit from Item_result_field*

1 files changed, 9 insertions, 9 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 62365f48404..eb9e0492dc7 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -16281,27 +16281,27 @@ Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
 
     /* Fall through */
   case Item::COND_ITEM:
+  case Item::SUBSELECT_ITEM:
+  case Item::REF_ITEM:
+  case Item::EXPR_CACHE_ITEM:
+    if (make_copy_field)
+    {
+      DBUG_ASSERT(((Item_result_field*)item)->result_field);
+      *from_field= ((Item_result_field*)item)->result_field;
+    }
+    /* Fall through */
   case Item::FIELD_AVG_ITEM:
   case Item::FIELD_STD_ITEM:
-  case Item::SUBSELECT_ITEM:
-    /* The following can only happen with 'CREATE TABLE ... SELECT' */
   case Item::PROC_ITEM:
   case Item::INT_ITEM:
   case Item::REAL_ITEM:
   case Item::DECIMAL_ITEM:
   case Item::STRING_ITEM:
   case Item::DATE_ITEM:
-  case Item::REF_ITEM:
   case Item::NULL_ITEM:
   case Item::VARBIN_ITEM:
   case Item::CACHE_ITEM:
-  case Item::EXPR_CACHE_ITEM:
   case Item::PARAM_ITEM:
-    if (make_copy_field)
-    {
-      DBUG_ASSERT(((Item_result_field*)item)->result_field);
-      *from_field= ((Item_result_field*)item)->result_field;
-    }
     return create_tmp_field_from_item(thd, item, table,
                                       (make_copy_field ? 0 : copy_func),
                                        modify_item);