A fix and test case for Bug#9777 " Empty set returned by Prepared Statement when it

 should return a non empty one"
(see comments for the changed files for details).


mysql-test/r/ps.result:
  A test case for Bug#9777: tests results fixed.
mysql-test/t/ps.test:
  A test case for Bug#9777
sql/item.cc:
  A fix for Bug#9777: when creating a constant item from within 
  Item_int_with_ref::new_item, create the item by value, not by name.
  This should work with prepared statements placeholders.
  Item_int_with_ref is a special optimization case used
   when we compare datetime constants with datetime value.
  Converting the item to integer early is OK as it is in line
  with the purpose of Item_int_with_ref - to speed up comparison by 
  using integers.
  Minor cleanups.
sql/item.h:
  Declaration for Item_int_with_ref::new_item

mysql-test/r/ps.result

@@ -519,3 +519,41 @@ c1	c2
 200887	860
 200887	200887
 deallocate prepare stmt;
+drop table t1;
+create table t1 (
+id bigint(20) not null auto_increment,
+code varchar(20) character set utf8 collate utf8_bin not null default '',
+company_name varchar(250) character set utf8 collate utf8_bin default null,
+setup_mode tinyint(4) default null,
+start_date datetime default null,
+primary key  (id), unique key code (code)
+);
+create table t2 (
+id bigint(20) not null auto_increment,
+email varchar(250) character set utf8 collate utf8_bin default null,
+name varchar(250) character set utf8 collate utf8_bin default null,
+t1_id bigint(20) default null,
+password varchar(250) character set utf8 collate utf8_bin default null,
+primary_contact tinyint(4) not null default '0',
+email_opt_in tinyint(4) not null default '1',
+primary key  (id), unique key email (email), key t1_id (t1_id),
+constraint t2_fk1 foreign key (t1_id) references t1 (id)
+);
+insert into t1 values
+(1, 'demo', 'demo s', 0, current_date()),
+(2, 'code2', 'name 2', 0, current_date()),
+(3, 'code3', 'name 3', 0, current_date());
+insert into t2 values
+(2, 'email1', 'name1', 3, 'password1', 0, 0),
+(3, 'email2', 'name1', 1, 'password2', 1, 0),
+(5, 'email3', 'name3', 2, 'password3', 0, 0);
+prepare stmt from 'select t2.id from t2, t1 where (t1.id=? and t2.t1_id=t1.id)';
+set @a=1;
+execute stmt using @a;
+id
+3
+select t2.id from t2, t1 where (t1.id=1 and t2.t1_id=t1.id);
+id
+3
+deallocate prepare stmt;
+drop table t1, t2;

mysql-test/t/ps.test

@@ -522,3 +522,50 @@ set @a=200887, @b=860;
 # this query did not return all matching rows
 execute stmt using @a, @b;
 deallocate prepare stmt;
+drop table t1;
+
+#
+# Bug#9777 - another occurrence of the problem stated in Bug#9096:
+# we can not compare basic constants by their names, because a placeholder
+# is a basic constant while his name is always '?'
+#
+
+create table t1 (
+   id bigint(20) not null auto_increment,
+   code varchar(20) character set utf8 collate utf8_bin not null default '',
+   company_name varchar(250) character set utf8 collate utf8_bin default null,
+   setup_mode tinyint(4) default null,
+   start_date datetime default null,
+   primary key  (id), unique key code (code)
+);
+
+create table t2 (
+   id bigint(20) not null auto_increment,
+   email varchar(250) character set utf8 collate utf8_bin default null,
+   name varchar(250) character set utf8 collate utf8_bin default null,
+   t1_id bigint(20) default null,
+   password varchar(250) character set utf8 collate utf8_bin default null,
+   primary_contact tinyint(4) not null default '0',
+   email_opt_in tinyint(4) not null default '1',
+   primary key  (id), unique key email (email), key t1_id (t1_id),
+   constraint t2_fk1 foreign key (t1_id) references t1 (id)
+);
+
+insert into t1 values
+(1, 'demo', 'demo s', 0, current_date()),
+(2, 'code2', 'name 2', 0, current_date()),
+(3, 'code3', 'name 3', 0, current_date());
+
+insert into t2 values
+(2, 'email1', 'name1', 3, 'password1', 0, 0),
+(3, 'email2', 'name1', 1, 'password2', 1, 0),
+(5, 'email3', 'name3', 2, 'password3', 0, 0);
+
+prepare stmt from 'select t2.id from t2, t1 where (t1.id=? and t2.t1_id=t1.id)';
+set @a=1;
+execute stmt using @a;
+
+select t2.id from t2, t1 where (t1.id=1 and t2.t1_id=t1.id);
+
+deallocate prepare stmt;
+drop table t1, t2;

sql/item.cc

@@ -769,6 +769,13 @@ Item_uint::Item_uint(const char *str_arg, uint length):
 }
 
 
+Item_uint::Item_uint(const char *str_arg, longlong i, uint length):
+  Item_int(str_arg, i, length)
+{
+  unsigned_flag= 1;
+}
+
+
 String *Item_uint::val_str(String *str)
 {
   // following assert is redundant, because fixed=1 assigned in constructor
@@ -1377,7 +1384,9 @@ Item_param::new_item()
   case NULL_VALUE:
     return new Item_null(name);
   case INT_VALUE:
-    return new Item_int(name, value.integer, max_length);
+    return (unsigned_flag ?
+            new Item_uint(name, value.integer, max_length) :
+            new Item_int(name, value.integer, max_length));
   case REAL_VALUE:
     return new Item_real(name, value.real, decimals, max_length);
   case STRING_VALUE:
@@ -2023,6 +2032,19 @@ bool Item_int::eq(const Item *arg, bool binary_cmp) const
 }
 
 
+Item *Item_int_with_ref::new_item()
+{
+  DBUG_ASSERT(ref->basic_const_item());
+  /*
+    We need to evaluate the constant to make sure it works with
+    parameter markers.
+  */
+  return (ref->unsigned_flag ?
+          new Item_uint(ref->name, ref->val_int(), ref->max_length) :
+          new Item_int(ref->name, ref->val_int(), ref->max_length));
+}
+
+
 Item_num *Item_uint::neg()
 {
   return new Item_real(name, - ((double) value), 0, max_length);

sql/item.h

@@ -651,6 +651,7 @@ class Item_uint :public Item_int
 {
 public:
   Item_uint(const char *str_arg, uint length);
+  Item_uint(const char *str_arg, longlong i, uint length);
   Item_uint(uint32 i) :Item_int((longlong) i, 10) 
     { unsigned_flag= 1; }
   double val()
@@ -1046,11 +1047,7 @@ class Item_int_with_ref :public Item_int
   {
     return ref->save_in_field(field, no_conversions);
   }
-  Item *new_item()
-  {
-    return (ref->unsigned_flag)? new Item_uint(ref->name, ref->max_length) :
-                                 new Item_int(ref->name, ref->max_length);
-  }
+  Item *new_item();
 };