BUG#912513: Wrong result (missing rows) with join_cache_hashed+materialization+semijoin=on

- equality substitution code was geared towards processing WHERE/ON clauses.
  that is, it assumed that it was doing substitions on the code that 
   = wasn't attached to any particular join_tab yet
   = was going to be fed to make_join_select() which would take the condition
     apart and attach various parts of it to tables inside/outside semi-joins.
- However, somebody added equality substition for ref access. That is, if 
  we have a ref access on TBL.key=expr, they would do equality substition in
  'expr'. This possibility wasn't accounted for.
- Fixed equality substition code by adding a mode that does equality 
  substition under assumption that the processed expression will be 
  attached to a certain particular table TBL.

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 81a18bb594e..ad4f889f4df 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -1712,7 +1712,7 @@ public:
   /** Add a non-constant item to the multiple equality */
   void add(Item *f) { equal_items.push_back(f); }
   bool contains(Field *field);
-  Item* get_first(Item *field);
+  Item* get_first(struct st_join_table *context, Item *field);
   /** Get number of field items / references to field items in this object */   
   uint n_field_items() { return equal_items.elements-test(with_const); }
   void merge(Item_equal *item);