From 419eb9aacc6b3a3d635030d5007ff6b4cbeccd9b Mon Sep 17 00:00:00 2001
From: unknown <gshchepa/uchum@gleb.loc>
Date: Sat, 10 Nov 2007 23:44:48 +0400
Subject: Fixed bug #28076: inconsistent binary/varbinary comparison.

After adding an index the <VARBINARY> IN (SELECT <BINARY> ...)
clause returned a wrong result: the VARBINARY value was illegally padded
with zero bytes to the length of the BINARY column for the index search.
(<VARBINARY>, ...) IN (SELECT <BINARY>, ... ) clauses are affected too.


sql/item.cc:
  Fixed bug #28076.
  The Item_cache_str::save_in_field method has been overloaded
  to check cached values for an illegal padding before the saving
  into a field.
sql/item.h:
  Fixed bug #28076.
  The Item_cache_str::is_varbinary flag has been added and the
  Item_cache_str::save_in_field method has been overloaded to prevent
  cached values from an illegal padding when saving in fields.
  The signature of the Item_cache::get_cache method has been
  changed to accept pointers to Item instead of Item_result
  values.
sql/item_cmpfunc.cc:
  Fixed bug #28076.
  The Item_in_optimizer::fix_left method has been modified to
  to call Item_cache::get_cache in a new manner.
sql/item_subselect.cc:
  Fixed bug #28076.
  The subselect_indexsubquery_engine::exec method has been
  modified to take into account field conversion errors
  (copy&paste from subselect_uniquesubquery_engine::exec).
sql/sp_rcontext.cc:
  Fixed bug #28076.
  The sp_rcontext::create_case_expr_holder method has been
  modified to call Item_cache::get_cache in a new manner.
sql/sp_rcontext.h:
  Fixed bug #28076.
  The sp_rcontext::create_case_expr_holder method signature
  has been modified to pass Item pointers to the
  Item_cache::get_cache method.
sql/sql_class.cc:
  Fixed bug #28076.
  The select_max_min_finder_subselect::send_data method has been
  modified to call Item_cache::get_cache in a new manner.
mysql-test/t/subselect.test:
  Added test case for bug #28076.
mysql-test/r/subselect.result:
  Added test case for bug #28076.
---
 sql/item.h | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

(limited to 'sql/item.h')

diff --git a/sql/item.h b/sql/item.h
index 2f504badec0..a1135c2c725 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -2469,7 +2469,7 @@ public:
   };
   virtual void store(Item *)= 0;
   enum Type type() const { return CACHE_ITEM; }
-  static Item_cache* get_cache(Item_result type);
+  static Item_cache* get_cache(const Item *item);
   table_map used_tables() const { return used_table_map; }
   virtual void keep_array() {}
   // to prevent drop fixed flag (no need parent cleanup call)
@@ -2531,9 +2531,16 @@ class Item_cache_str: public Item_cache
 {
   char buffer[STRING_BUFFER_USUAL_SIZE];
   String *value, value_buff;
+  bool is_varbinary;
+  
 public:
-  Item_cache_str(): Item_cache(), value(0) { }
-
+  Item_cache_str(const Item *item) :
+    Item_cache(), value(0),
+    is_varbinary(item->type() == FIELD_ITEM &&
+                 ((const Item_field *) item)->field->type() ==
+                   MYSQL_TYPE_VARCHAR &&
+                 !((const Item_field *) item)->field->has_charset())
+  {}
   void store(Item *item);
   double val_real();
   longlong val_int();
@@ -2541,6 +2548,7 @@ public:
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type() const { return STRING_RESULT; }
   CHARSET_INFO *charset() const { return value->charset(); };
+  int save_in_field(Field *field, bool no_conversions);
 };
 
 class Item_cache_row: public Item_cache
-- 
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