Merge branch '10.2' into 10.3

1 files changed, 17 insertions, 10 deletions

diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 4603a85aa87..1bac7b6e527 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -1518,16 +1518,23 @@ bool Item_exists_subselect::fix_length_and_dec()
 {
   DBUG_ENTER("Item_exists_subselect::fix_length_and_dec");
   init_length_and_dec();
-  /*
-    We need only 1 row to determine existence (i.e. any EXISTS that is not
-    an IN always requires LIMIT 1)
-  */
-  Item *item= new (thd->mem_root) Item_int(thd, (int32) 1);
-  if (!item)
-    DBUG_RETURN(TRUE);
-  thd->change_item_tree(&unit->global_parameters()->select_limit,
-                        item);
-  DBUG_PRINT("info", ("Set limit to 1"));
+  // If limit is not set or it is constant more than 1
+  if (!unit->global_parameters()->select_limit ||
+      (unit->global_parameters()->select_limit->basic_const_item() &&
+       unit->global_parameters()->select_limit->val_int() > 1))
+  {
+    /*
+       We need only 1 row to determine existence (i.e. any EXISTS that is not
+       an IN always requires LIMIT 1)
+     */
+    Item *item= new (thd->mem_root) Item_int(thd, (int32) 1);
+    if (!item)
+      DBUG_RETURN(TRUE);
+    thd->change_item_tree(&unit->global_parameters()->select_limit,
+                          item);
+    unit->global_parameters()->explicit_limit= 1; // we set the limit
+    DBUG_PRINT("info", ("Set limit to 1"));
+  }
   DBUG_RETURN(FALSE);
 }