Post-merge fixes for Bug#9096 "select doesn't return all matched

records if prepared statements is used" (see comments to 
the changed files).


mysql-test/r/ps.result:
  Post-merge fix for Bug#9096: test results fixed.
mysql-test/r/type_datetime.result:
  Post-merge fix for Bug#9096: now we do better constants comparison,
  so the optimizer is able to guess from the index that we don't
  need to evaluate WHERE clause.
sql/item.cc:
  Post-merge fixes for Bug#9096: implement by-value comparison for
  new 5.0 DECIMAL type.
  Item_real is renamed to Item_float in 5.0
  Item_varbinary is renamed to Item_hex_string in 5.0
sql/item.h:
  Post-merge fixes for Bug#9096: declaration for Item_decimal::eq

mysql-test/r/ps.result

@@ -570,3 +570,28 @@ id
 deallocate prepare stmt|
 drop procedure p1|
 drop table t1|
+drop table if exists t1;
+Warnings:
+Note	1051	Unknown table 't1'
+create table t1 (c1 int(11) not null, c2 int(11) not null,
+primary key  (c1,c2), key c2 (c2), key c1 (c1));
+insert into t1 values (200887, 860);
+insert into t1 values (200887, 200887);
+select * from t1 where (c1=200887 and c2=200887) or c2=860;
+c1	c2
+200887	860
+200887	200887
+prepare stmt from
+"select * from t1 where (c1=200887 and c2=200887) or c2=860";
+execute stmt;
+c1	c2
+200887	860
+200887	200887
+prepare stmt from
+"select * from t1 where (c1=200887 and c2=?) or c2=?";
+set @a=200887, @b=860;
+execute stmt using @a, @b;
+c1	c2
+200887	860
+200887	200887
+deallocate prepare stmt;

mysql-test/r/type_datetime.result

@@ -88,7 +88,7 @@ date	numfacture	expedition
 0000-00-00 00:00:00	1212	0001-00-00 00:00:00
 EXPLAIN SELECT * FROM t1 WHERE expedition='0001-00-00 00:00:00';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	expedition	expedition	8	const	1	Using where
+1	SIMPLE	t1	ref	expedition	expedition	8	const	1	
 drop table t1;
 create table t1 (a datetime not null, b datetime not null);
 insert into t1 values (now(), now());

sql/item.cc

@@ -1448,6 +1448,24 @@ void Item_decimal::print(String *str)
 }
 
 
+bool Item_decimal::eq(const Item *item, bool binary_cmp) const
+{
+  if (type() == item->type() && item->basic_const_item())
+  {
+    /*
+      We need to cast off const to call val_decimal(). This should
+      be OK for a basic constant. Additionally, we can pass 0 as
+      a true decimal constant will return its internal decimal
+      storage and ignore the argument.
+    */
+    Item *arg= (Item*) item;
+    my_decimal *value= arg->val_decimal(0);
+    return !my_decimal_cmp(&decimal_value, value);
+  }
+  return 0;
+}
+
+
 String *Item_float::val_str(String *str)
 {
   // following assert is redundant, because fixed=1 assigned in constructor
@@ -2217,7 +2235,7 @@ Item_param::new_item()
   case INT_VALUE:
     return new Item_int(name, value.integer, max_length);
   case REAL_VALUE:
-    return new Item_real(name, value.real, decimals, max_length);
+    return new Item_float(name, value.real, decimals, max_length);
   case STRING_VALUE:
   case LONG_DATA_VALUE:
     return new Item_string(name, str_value.c_ptr_quick(), str_value.length(),
@@ -2251,7 +2269,7 @@ Item_param::eq(const Item *arg, bool binary_cmp) const
     return value.integer == item->val_int() &&
            unsigned_flag == item->unsigned_flag;
   case REAL_VALUE:
-    return value.real == item->val();
+    return value.real == item->val_real();
   case STRING_VALUE:
   case LONG_DATA_VALUE:
     if (binary_cmp)
@@ -3520,7 +3538,7 @@ void Item_float::print(String *str)
   In number context this is a longlong value.
 */
 
-bool Item_real::eq(const Item *arg, bool binary_cmp) const
+bool Item_float::eq(const Item *arg, bool binary_cmp) const
 {
   if (arg->basic_const_item() && arg->type() == type())
   {
@@ -3529,7 +3547,7 @@ bool Item_real::eq(const Item *arg, bool binary_cmp) const
       a basic constant.
     */
     Item *item= (Item*) arg;
-    return item->val() == value;
+    return item->val_real() == value;
   }
   return FALSE;
 }
@@ -3605,7 +3623,7 @@ int Item_hex_string::save_in_field(Field *field, bool no_conversions)
 }
 
 
-bool Item_varbinary::eq(const Item *arg, bool binary_cmp) const
+bool Item_hex_string::eq(const Item *arg, bool binary_cmp) const
 {
   if (arg->basic_const_item() && arg->type() == type())
   {

sql/item.h

@@ -1039,8 +1039,10 @@ public:
     unsigned_flag= !decimal_value.sign();
     return this;
   }
+  bool eq(const Item *, bool binary_cmp) const;
 };
 
+
 class Item_float :public Item_num
 {
   char *presentation;