Improved comments

1 files changed, 5 insertions, 1 deletions

diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index a125a119ad8..97ded8bdd55 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -179,7 +179,11 @@ public:
     rewriting, mandated by a SQL:2003 exception in the specification.
     The only caller of this method is handle_sql2003_note184_exception(),
     see the code there for more details.
-    Do not call this method for other purposes.
+    Note that this method breaks the object internal integrity, by
+    removing it's association with the corresponding SELECT_LEX,
+    making this object orphan from the parse tree.
+    No other method, beside the destructor, should be called on this
+    object, as it is now invalid.
     @return the SELECT_LEX structure that was given in the constructor.
   */
   st_select_lex* invalidate_and_restore_select_lex();